PATENT DOCUMENT

Publication Number: US-10396339-B1
Application Number: US-201615093675-A
Country: US
Kind Code: B1

Title: Bi-metal battery tab

Abstract:
A bi-metal tab includes an internal tab segment that can be coupled to a battery cell terminal within an interior of the cell and an external tab segment that can be coupled to an element external to the cell. One tab segment includes a pin tab segment that comprises a pin, and another tab segment includes a socket tab segment comprised of a separate metal material, that comprises a socket. The socket can be at least partially enclosed, on at least two opposing sides, by the structure of the socket tab segment, and the socket and pin of the separate segments can be configured to couple, to form the tab, where at least two surfaces of the pin are in flush contact with the socket tab segment structure. A protection layer that restricts electronic transport across the tab based on exposure to particular physical conditions can be included between the tab segments.

Claims:
What is claimed is: 
     
       1. A battery, comprising:
 a conductive tab fixed to the battery and in electrical communication with a battery cell terminal of a battery cell of the battery, the conductive tab positioned partially external to the battery cell, the conductive tab comprising:
 a socket segment composed at least in part of a first metal; and 
 a pin segment composed at least in part of a second metal, the pin segment comprising a pin surface positioned at least partially within the socket segment and in contact with at least a first socket wall of the socket segment, 
 
 wherein the conductive tab is configured to electrically connect the battery to an external component to provide power from the battery, and wherein the conductive tab including the socket segment and the pin segment remain fixed to the battery when the battery is not connected to the external component. 
 
     
     
       2. The battery of  claim 1 , further comprising a seal positioned at a boundary of an internal portion of the battery cell, the seal positioned about a portion of the conductive tab. 
     
     
       3. The battery of  claim 1 , further comprising a seal positioned about a portion of the conductive tab, the seal at least partially covering a joint between the socket segment and the pin segment. 
     
     
       4. The battery of  claim 1 , further comprising a protection layer in contact with at least a portion of the pin surface and at least a portion of the first socket wall, the protection layer positioned between the pin surface and the first socket wall. 
     
     
       5. The battery of  claim 4 , wherein the protection layer is configured to, in response to exposure of the protection layer to one or more physical conditions, at least partially inhibit electrical transmission within the battery. 
     
     
       6. The battery of  claim 1 , further comprising a protection layer in contact with at least a portion of the pin surface and at least a portion of a second socket wall of the socket segment. 
     
     
       7. The battery of  claim 1 , wherein the socket segment and pin segment are laminated together. 
     
     
       8. The battery of  claim 1 , wherein no portion of the pin segment is exposed within the battery cell. 
     
     
       9. The battery of  claim 1 , wherein the second metal is aluminum. 
     
     
       10. The battery of  claim 1 , wherein the first metal is either copper or nickel. 
     
     
       11. A method, comprising:
 at least partially fabricating a battery, the at least partially fabricating the battery comprising:
 fabricating a conductive tab fixed to the battery and in electrical communication with a battery cell terminal of a battery cell of the battery, the conductive tab comprising:
 a socket segment composed at least in part of a first metal; and 
 a pin segment composed at least in part of a second metal, the pin segment positioned at least partially external to the battery cell, the pin segment comprising a pin surface positioned at least partially within the socket segment and in contact with at least a portion of a socket wall of the socket segment, 
 
 wherein the conductive tab is configured to electrically connect the battery to an external component to provide power from the battery, and wherein the conductive tab including the socket segment and the pin segment remain fixed to the battery when the battery is not connected to the external component. 
 
 
     
     
       12. The method of  claim 11 , further comprising joining the socket segment and the pin segment by lamination. 
     
     
       13. The method of  claim 11  further comprising joining the socket segment and the pin segment by press-fitting. 
     
     
       14. The method of  claim 11 , further comprising fabricating a seal positioned at a boundary of an internal portion of the battery cell, the seal positioned about a portion of the conductive tab. 
     
     
       15. The method of  claim 11 , further comprising fabricating a protection layer in contact with at least a portion of the pin surface and at least a portion of the socket wall, the protection layer positioned between the pin surface and the socket wall. 
     
     
       16. The method of  claim 15 , wherein the protection layer is configured to, in response to exposure of the protection layer to one or more physical conditions, at least partially inhibit electrical transmission within the battery. 
     
     
       17. The method of  claim 16 , wherein the one or more particular physical conditions comprise one or more of:
 a temperature condition; 
 a voltage condition; 
 a current condition; and 
 a pressure condition. 
 
     
     
       18. The method of  claim 11 , further comprising fabricating a protection layer in contact with at least a portion of the socket segment external the socket wall and at least a portion of the pin segment. 
     
     
       19. A portable electronic device, comprising:
 at least one functional component configured to consume electrical power; and 
 a battery configured to provide electrical power support to the at least one functional component, the battery comprising a battery cell and a conductive tab fixed to the battery, the conductive tab comprising:
 a socket segment composed at least in part of a first metal; and 
 a pin segment composed at least in part of a second metal, the pin segment positioned at least partially external to the battery cell, the pin segment comprising a pin surface positioned at least partially within the socket segment and in contact with at least a first socket wall of the socket segment, 
 wherein the conductive tab is configured to electrically connect the battery to the at least one functional component to provide power from the battery, and wherein the conductive tab including the socket segment and the pin segment remain fixed to the battery when the battery is not connected to the at least one functional component. 
 
 
     
     
       20. The portable electronic device of  claim 19 , wherein the battery further comprises a seal positioned at a boundary of an internal portion of the battery cell, the seal positioned about at least a portion of the conductive tab.

Description:
This application claims priority from U.S. Provisional Application No. 62/144,295, entitled “Bi-Metal Battery Tab” and filed Apr. 7, 2015, the contents of which is incorporated by reference in its entirety herein. 
    
    
     BACKGROUND 
     Technical Field 
     The disclosed embodiments relate to batteries configured to provide electrical power. More specifically, the disclosed embodiments relate to bi-metal tabs that can electrically couple one or more terminals of a battery cell to one or more other elements external to the battery cell. 
     Description of the Related Art 
     Rechargeable batteries are presently used to provide power to a wide variety of portable electronic devices, including laptop computers, cell phones, PDAs, digital music players and cordless power tools. As these electronic devices become increasingly smaller and more powerful, the batteries that are used to power these devices need to store more energy in a smaller volume. 
     The most commonly used type of rechargeable battery is a lithium battery, which can include a lithium-ion battery, a lithium-polymer battery, any of various other lithium battery variations, or a combination of the foregoing. Lithium batteries typically contain, among other parts, a cathode current collector, a cathode comprised of an active material, a separator, an anode current collector, and an anode comprised of an active material. The cathode can comprise a cathode coating and the anode can comprise an anode coating. 
     A battery cell can include a tab that can electrically couple a battery cell to another portion of the battery. For example, where a battery includes multiple battery cells, the terminals of the battery cells can be coupled to a bus bar via separate tabs. 
     SUMMARY OF EMBODIMENTS 
     A bi-metal tab that is configured to electrically couple a battery cell terminal to an element external to the battery cell includes an internal tab segment that can be coupled to a battery cell terminal within an interior of the cell and an external tab segment that can be coupled to an element external to the cell. One tab segment includes a pin tab segment that comprises a pin, and another tab segment includes a socket tab segment comprised of a separate metal material, that comprises a socket. The socket can be at least partially enclosed, on at least two opposing sides, by the structure of the socket tab segment, and the socket and pin of the separate segments can be configured to couple, to form the tab, where at least two surfaces of the pin are in flush contact with the socket tab segment structure. A protection layer restricts electronic transport across the tab based on exposure to particular physical conditions can be included between the tab segments. 
     Some embodiments include an apparatus that further includes a pin tab segment and a socket tab segment that are coupled together via an engagement of a pin included in the pin tab segment with a socket included in the socket tab segment. The socket tab segment includes at least two socket structures that bound opposite sides of the socket, and engaging the pin with the socket includes engaging opposite surfaces of the pin in flush contact with the at least two socket structures. The pin can be configured to be enclosed within the socket when the pin is engaged with the socket. One or more of the pin and the socket can be configured to accommodate at least one protection layer on at least one surface of the at least one of the socket and the pin, so that the tab includes at least one protection layer that is located between the pin tab segment and the socket tab segment and that is configured to at least partially restrict electronic transport between the pin tab segment and the socket tab segment based on exposure to one or more particular physical conditions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a battery that comprises bi-metal tabs that couple battery cell terminals to elements external to a battery cell, according to some embodiments. 
         FIGS. 2A and 2B  illustrate orthogonal views of a bi-metal tab that comprises a pin tab segment and a socket tab segment that are configured to be coupled together via engagement of a pin structure of the pin tab segment with a socket of the socket tab segment, according to some embodiments. 
         FIGS. 3A and 3B  illustrate orthogonal views of a bi-metal tab, where the separate segments comprising the tab are coupled, in a complete fit of the socket and pin established via engaging the pin with the socket, to form the tab, according to some embodiments. 
         FIGS. 4A-D  illustrate cross sections of a tab comprising the coupled pin tab segments and socket tab segments, according to some embodiments. 
         FIGS. 5A and 5B  illustrate a bi-metal tab that includes a protection layer, according to some embodiments. 
         FIGS. 6A-C  illustrate a bi-metal tab that includes a pin tab segment and a socket tab segment configured to couple so that at least one surface of the pin structure remains exposed, according to some embodiments. 
         FIG. 7  illustrates a fabrication system configured to fabricate a bi-metal tab, according to some embodiments. 
         FIG. 8  illustrates a fabrication system configured to fabricate a battery, according to some embodiments. 
     
    
    
     This specification includes references to “one embodiment” or “an embodiment.” The appearances of the phrases “in one embodiment” or “in an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure. 
     “Comprising.” This term is open-ended. As used in the appended claims, this term does not foreclose additional structure or steps. Consider a claim that recites: “An apparatus comprising one or more processor units . . . .” Such a claim does not foreclose the apparatus from including additional components (e.g., a network interface unit, graphics circuitry, etc.). 
     “Configured To.” Various units, circuits, or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the units/circuits/components include structure (e.g., circuitry) that performs those task or tasks during operation. As such, the unit/circuit/component can be said to be configured to perform the task even when the specified unit/circuit/component is not currently operational (e.g., is not on). The units/circuits/components used with the “configured to” language include hardware—for example, circuits, memory storing program instructions executable to implement the operation, etc. Reciting that a unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112, sixth paragraph, for that unit/circuit/component. Additionally, “configured to” can include generic structure (e.g., generic circuitry) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in manner that is capable of performing the task(s) at issue. “Configure to” may also include adapting a manufacturing process (e.g., a semiconductor fabrication facility) to fabricate devices (e.g., integrated circuits) that are adapted to implement or perform one or more tasks. 
     “First,” “Second,” etc. As used herein, these terms are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, a buffer circuit may be described herein as performing write operations for “first” and “second” values. The terms “first” and “second” do not necessarily imply that the first value must be written before the second value. 
     “Based On.” As used herein, this term is used to describe one or more factors that affect a determination. This term does not foreclose additional factors that may affect a determination. That is, a determination may be solely based on those factors or based, at least in part, on those factors. Consider the phrase “determine A based on B.” While in this case, B is a factor that affects the determination of A, such a phrase does not foreclose the determination of A from also being based on C. In other instances, A may be determined based solely on B. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Various embodiments of an apparatus that includes a bi-metal tab configured to electrically couple a battery cell terminal to an element external to the battery cell are disclosed. 
       FIG. 1  illustrates a battery that comprises bi-metal tabs that couple battery cell terminals to elements external to a battery cell, according to some embodiments. 
     The battery  100  shown in  FIG. 1  includes a battery cell  110  that includes an anode  150  and cathode  140  and current collectors  120 A and  120 B coupled to distal surfaces of the electrodes  140 ,  150  respectively, where the distal surfaces include, on each electrode of electrodes  140 ,  150 , at least one surface that face away from the other electrode of electrodes  140 ,  150 . The battery cell  110  may further include one or more electrolyte substances positioned between the anode  150  and the cathode  140 . Battery cell  110  further includes a battery separator layer  160  that separates the two electrodes, and an electrolyte  170  in that at least some of the components of the cell  110  are immersed. The electrolyte  170  can include one or more various liquid electrolytes. In some embodiments, the liquid electrolyte is included in a limited portion of the battery  100 , including a limited portion of the cell. For example, the electrolyte  170  can be included in the separator  160  and not in other portions of the cell. In some embodiments, the cell includes one or more electrolyte layers  180  that are located between the electrodes. The electrolyte layer  180  can include a solid electrolyte layer. In some embodiments, the separator  160  is absent from cell  110 . Specifically, although shown in  FIG. 1  as having both a separator  160  with a liquid electrolyte  170  and a solid electrolyte layer  180 , it should be appreciated that at least some of the battery embodiments discussed here may include a separator  160  with liquid electrolyte  170  and no solid electrolyte layer  180 , at least some of the battery embodiments discussed here may include a solid electrolyte layer  180  and no separator  160  and liquid electrolyte  170 , etc. 
     A battery cell  110  can include at least one cathode  140 , anode  150 , and electrolyte  170 ,  180  that are comprised of various materials. In some embodiments, a battery cell  110  includes a cathode  140  that is comprised of one or more various metal oxides. The battery cell  110  can include electrolytes in one or more various phases. For example, a battery  100  that includes a lithium battery can include a liquid electrolyte  170  that can include one or more various lithium salts in an organic solvent. In some embodiments, a battery  100  that can include a lithium battery, includes an electrolyte layer  180 , in one or more cells  110  that includes a molten salt layer. In another example, a battery  100  that can include a lithium battery, can include one or more solid electrolyte layers  180  that can include lithium phosphorous oxynitride (“LiPON”) that can be mixed with one or more various binder substances that can include one or more of polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), one or more Acrylic substances, etc. A solid electrolyte can form a layer in a battery cell between the electrodes  140 ,  150  of the battery cell  110 . In some embodiments, a battery cell  110  includes at least one liquid electrolyte and at least one solid electrolyte. 
     In some embodiments, battery cell  110  includes a separator  160  that comprises an at least partially permeable structure that permits the transport of at least some charge carriers, including one or more ions, between the electrodes  140 ,  150  of the cell  110 . In some embodiments, the battery cell  110  is a lithium ion battery cell that comprises a separator  160  that permits the transport  192  of lithium ions between the electrodes  140 ,  150  of the cell  110 . In some embodiments, the separator  160  includes one or more pores via that one or more charge carriers can pass. In some embodiments, the separator comprises a polymer separator. In some embodiments, the separator  160  is configured to inhibit the charge carrier transport between the electrodes based at least in part upon a temperature to that the separator  160  is exposed. Exposure of a component, including one or more layers, of a battery cell to one or more conditions can include the component having that condition; for example, exposure of the separator  160  to a particular temperature can be referred to as at least one portion of the separator  160  being at the particular temperature, the particular temperature being the temperature of the separator  160 , etc. A separator  160  can be referred to as a “shutdown separator”, because, by forming an impermeable structure and inhibiting ion transport  192  based on temperature, the separator  160  is configured to shut down the battery cell  110  in response to the battery temperature exceeding a certain temperature. As a result, in addition to keeping the electrodes separated, the separator  160  mitigates safety hazards associated with operation of the battery  100 . Such a configuration can be associated with the physical structure and composition of the separator. For example, a shutdown separator can be at least partially comprised of one or more polymer materials, including polyethylene, that can melt in response to the local temperature exceeding a threshold, where the melted material coats one or more portions of the separator with a nonconductive layer that inhibits charge carrier transport across the separator, and thus inhibits charge carrier transport between the electrodes. 
     In some embodiments, a battery  100  comprises a lithium battery  100  that is independent of any battery separator  160 . For example, battery cell  110  can include an electrolyte layer  180  that can include a layer including a solid electrolyte material and does not include a separator  160  between the electrodes  140 ,  150 . In some embodiments, battery cell  110  includes a liquid electrolyte  170  that is included within one or more other portions of the battery, including one or more electrodes, such that the liquid electrolyte  170  enables ion transport  192  between a solid electrolyte layer  180  and one or more other portions of the battery. For example, where layer  180  is a solid electrolyte layer, cathode  140  can comprise a porous structure in that a liquid electrolyte  170  is included, where the liquid electrolyte  170  can enable ion transport  192  between the solid electrolyte layer  180  and the cathode  140 . 
     In some embodiments, the anode  150  of one or more battery cells  110  is comprised of one or more materials that include lithium metal. For example, the anode  150  can be comprised entirely of lithium metal. 
     Current collectors  120 A and  120 B shown in  FIG. 1  each include a foil layer  124 A or  124 B coupled to an electrode, an electric terminal  122 A or  122 B coupled to the respective foil layer  124 A or  124 B, and a tab  126 A or  126 B that is coupled to the respective terminal  122 A or  122 B. Each tab  126  can couple with one or more elements external to the battery cell  110 , including portions of the battery  100  that are external to the cell  110 . As shown, each tab  126 A or  126 B can be coupled to a separate connector  128 A or  128 B of an external element. In some embodiments, the connectors  128 A and  128 B are included in one or more bus bars. Coupling a tab  126  to a connector  128  can include electrically coupling at least the terminal  122 , via the tab  126 , to the connector  128 . As a result, coupling tabs  126 A and  126 B with connectors  128 A and  128 B can result in facilitating electronic transport between cell  110  and one or more external elements via one or more of the tabs  126 A and  126 B. 
     As shown, cell  110  includes seals  130 A and  130 B that are each coupled to a separate tab  126 A or  126 B and are each configured to isolate an interior of the cell  110  from an exterior of the cell  110 . A seal  130  is configured to seal off a portion of the cell exterior  110  through which a tab  126  extends, thereby isolating the cell  110  interior from the exterior and mitigating transfer of internal cell  110  components, including electrolyte  170  substances, through a portion of the cell  110  exterior through which the tab  126  extends. 
     In some embodiments, a tab  126 A or  126 B is comprised of one or more various materials that are configured to conduct electricity, thereby enabling electronic transport across the tab. The one or more various materials can include one or more metal materials. For example, a tab  126  can be comprised of one or more of aluminum, copper, nickel, iron, tin, titanium, any other known metallic composition, etc. In some embodiments, a tab comprises one or more of a laminated material, an alloy material, etc. 
     Current collectors  120 A and  120 B each comprise a respective foil layer  124 . A foil layer can facilitate electron transport, also referred to herein as electronic transport  194 , between an electrode and an electric terminal. A foil layer can extend over some or all of a surface of an electrode, thereby enabling an increased uniformity in electronic transport across the surface of the electrode. For example, foil layer  124 A in  FIG. 1  extends over a surface of cathode  140  and facilitates electronic transport between the cathode  140  and the terminal  122 A of the current collector  120 A. The foil layer  124 A can be comprised of a conductive material, including one or more metallic substances that conducts electrical power between the cathode  140  and the terminal  122 A. 
     In some embodiments, a foil layer, to be “coupled” to an electrode layer, is applied to the electrode layer. Applying a layer can be referred to herein interchangeably as adhering a layer, and one or more substances can be applied to a foil layer to facilitate adhesion of a foil layer to an applied electrode layer. For example, a given surface of a foil layer can be coated with a layer of carbon black and applied to an electrode layer, where the carbon black material augments adhesion of the foil layer to the electrode layer. 
     In some embodiments, coupling a foil layer to an electrode layer includes application of the electrode layer to the foil layer, such that the foil layer is a substrate upon that at least a portion of the electrode layer is applied. Applying a layer can be referred to herein interchangeably as adhering a layer, and one or more substances can be applied to a foil layer to facilitate adhesion of a foil layer to an applied electrode layer. For example, a given surface of a foil layer can be coated with a layer of carbon black and an electrode layer can be applied to the carbon black layer, where the carbon black material augments adhesion of the foil layer to the electrode layer. 
     In some embodiments, a tab that can be coupled to a terminal of a battery cell and can couple the terminal to an element that is external to the cell is comprised of multiple separate metal materials. The tab can be comprised of separate tab segments that are coupled together and that are each comprised of a separate metal material. One or more of the metal materials, referred to herein as internal metal materials, can be configured to be in contact with one or more components of the battery cell interior, and one or more separate metal materials, referred to herein as external metal materials, included in the tab can be configured to be in contact with one or more elements external to the battery cell. 
     For example, a tab can be comprised of a particular tab segment that is comprised of an internal metal material and a separate segment that is comprised of an external metal material. The particular segment that is comprised of an internal metal material can be referred to herein as the internal tab segment, and the separate segment that is comprised of an external metal material can be referred to herein as the external tab segment. 
     The internal metal material can be configured to resist reaction with various components within a battery cell. For example, the internal tab segment can be comprised of an internal metal material that is chemically neutral, inert, etc. with regard to one or more electrolyte substances included within the interior of the battery cell. As a result, the internal tab segment, when located at least partially within the interior of the battery cell, is resistant to damage resulting from exposure to internal battery cell components. In another example, the external tab segment can be comprised of an external metal material that may be at least partially reactive with regard to one or more components of the battery cell interior, including one or more electrolyte substances included therein. The external metal material can be less expensive than the internal metal material, more conductive, etc. As a result, the external metal material can be advantageous to include in portions of a tab that are exposed to an exterior of the battery cell, as reduced usage of internal metal material may be advantageous through reducing a cost of the cell. 
     A tab that includes two separate segments, comprised of separate ones of an internal metal material or an external metal material, is referred to herein as a bi-metal tab. In some embodiments, the internal tab segment is comprised of an internal metal material that includes one or more of nickel, copper, etc. In some embodiments, the external tab segment is comprised of an external metal material that includes one or more of aluminum. 
     In some embodiments, the separate tab segments included in a bi-metal tab are coupled together to form the bi-metal tab. Separate tab segments can be coupled via one or more various metal segment bonding techniques known in the art, including one or more of laminating separate tab segments together, press-fitting separate segments together, bonding separate segments together, etc. In some embodiments, separate tab segments are coupled together at corresponding flush cross sections, resulting in a contact area between the two tab segments that approximately corresponds to a cross-sectional area of the tab. In some embodiments, the separate tab segments each include complementary ends that are angled, resulting in a contact area that is greater than the tab cross section when the tab segments are coupled together. Increased contact area between the metal materials of the separate tab segments can augment performance of a tab, based at least in part upon reduced resistance of conduction between the separate tab segments that can result from increased contact area and increased mechanical strength of the joint between tab segments. 
     In some embodiments, a bi-metal tab comprises two separate segments that are configured to couple in a pin and socket configuration, where one tab segment comprises a pin structure and another tab segment comprises a socket structure and where the pin structure and the socket structure are configured to engage in a complete fit. As referred to herein, a complete fit between a pin structure and a socket structure includes the pin being coupled to the socket so that the pin substantially encompasses the volume of the socket and the surfaces of the pin are substantially in contact with the surfaces of the socket. As referred to herein, substantially encompassing the volume of the socket can include encompassing the volume of the socket to the extent permitted by the fabrication tolerances of components and processes via that the pin and socket structures are fabricated. 
     In some embodiments, a bi-metal tab that comprises a pin tab segment and a socket tab segment can include an increased contact area between the separate segments when the pin tab segment is coupled to the socket tab segment, thereby providing reduced resistance of electrical conduction between the separate tab segments and thus reduced resistance of the tab to electrical conduction, relative to other tabs having less contact area between separate tab segments. As referred to herein, coupling the pin tab segment with the socket tab segment can include engaging a pin structure of the pin tab segment into a socket of the socket tab segment that results in a complete fit between the pin structure and the socket. Such engaging can include inserting the pin structure into the socket, slidably engaging the pin structure into the socket, some combination thereof, etc. In some embodiments, the socket tab segment comprises the internal tab segment and is comprised of an internal metal material, and the pin tab segment comprises the external tab segment and is comprised of an external metal material. In some embodiments, the socket tab segment comprises the external tab segment and is comprised of an external metal material, and the pin tab segment comprises the internal tab segment and is comprised of an internal metal material. 
     In some embodiments, the pin and socket configuration of the tab segments provides augmented physical strength of the tab when the segments are coupled together, relative to a tab that comprises separate tab segments coupled via a plane of contact, including a coupling of cross sections, angled planes, etc. Because the pin structure is bounded by at least a portion of the socket structure, the resulting tab can be more resistant to shear forces than a tab formed from coupling cross sections, planes, etc. of separate tab segments. In addition, where a pin tab segment is comprised of external metal material and is at least partially bounded by the socket structure of the socket tab segment when the pin tab segment is coupled with the socket tab segment, at least a portion of the internal metal material can be located within the interior of the battery cell, as the socket tab segment material can preclude the internal metal material from being exposed to internal battery cell components, thereby enabling a reduced amount of the tab being located external to the cell and enabling reduced utilization of internal metal material, as the internal tab segment can be a sheath for the internal metal material located within the battery cell interior rather than comprising a partial, majority, entirety, etc. fraction of the tab. 
       FIGS. 2A and 2B  illustrate orthogonal views of a bi-metal tab  200  that comprises a pin tab segment  210  and a socket tab segment  220  that are configured to be coupled together via engaging a pin structure of the pin tab segment with a socket of the socket tab segment, according to some embodiments. Engaging the pin structure with the socket can include engaging the pin structure and the socket in a complete fit. A coupling of a pin tab segment and a socket tab segment that includes engaging the pin structure in the socket can be referred to herein as a pin-socket interlock. 
       FIGS. 2A and 2B  illustrate orthogonal views  201 ,  250  of the separate segments  210 ,  220  comprising the tab  200  in a configuration where the separate segments  210 ,  220  are in a decoupled configuration. The tab  200  illustrated in  FIGS. 2A and 2B  can be included in any of the embodiments of a bi-metal tab herein, including one or more of the tabs  126 A and  126 B illustrated in  FIG. 1 . 
     Pin tab segment,  210 , also referred to herein as a “pin segment”, includes an outer body  212  that has a certain width  249  and height  231  and a pin structure  216 , also referred to herein as a “pin”, that protrudes outward from one end of the outer body  212  to a depth  218  and has a certain width  245  and height  233 . In some embodiments, including the illustrated embodiment shown in  FIGS. 2A and 2B , one or more of the width  245  and height  233  of the pin  216  is less than that of the corresponding width  249  and height  231  of the outer body  212 . The pin  216  can be spaced inward, in at least one dimension, from at least two opposing surfaces of the outer body  212 , so that a body surface  213  is present adjacent to opposite surfaces of the pin  216  and the opposite surfaces of the pin  216  are not flush with the corresponding opposite surfaces of the outer body  212 . For example, as shown in the illustrated embodiment, a body surface  213  is present adjacent to opposite pin surfaces  217 A and  217 B and  217 C and  217 D and none of the surfaces  217  of the pin  216  are flush with the surfaces of the outer body  212 . 
     Socket tab segment,  220 , also referred to herein as a “socket segment”, includes an outer body  222  that has a certain width  247  and height  235  and a socket  226  that protrudes inward into the interior of the segment  220  from one end of the outer body  22  to a depth  228  and has a certain width  243  and height  237 . In some embodiments, including the illustrated embodiment shown in  FIGS. 2A and 2B , one or more of the width  243  and height  237  of the socket  226  is less than that of the corresponding width  247  and height  235  of the outer body  222 , that results in at least a portion of the socket  226  being bounded by one or more socket structures of the segment  220 . The socket structures  227  that bound one or more portions of the socket can be referred to herein as “socket walls”. In the illustrated embodiment, the width  243  and height  237  of socket  226  is less than the width  247  and height  235  of the outer body  222 , so the socket  226  is bounded by socket structures  227 A- 227 D that collectively bound the width and the height of the socket. The socket  226  has an opening  229  in the segment  220  that is unbounded by socket structure. In some embodiments, the socket  226  is bounded on opposite sides by two or more socket walls. For example, in the illustrated embodiment, socket  226  is bounded on opposite sides by opposite walls  227 A and  227 B and is further bounded on opposite sides by opposite walls  227 C and  227 D. 
     In some embodiments, one or more of the pin  216  and the socket  226  is configured to establish a complete fit with one or more of the socket  226  and the pin  216  when the pin  216  is engaged with the socket  226 . In the illustrated embodiment, both the socket  226  and the pin  216  are configured to establish a complete fit with each other when the pin  216  is engaged into the socket  226  via socket opening  229 . For example, the height  223 , depth  218 , and width  245  of pin  216  can match, within fabrication tolerances, the height  237 , depth  228 , and width  243  of socket  226 , so that, when pin  216  is engaged into socket  226 , the pin surfaces  217 A-E of pin  216  can each be in flush contact with a corresponding portion of the socket tab segment that bounds a corresponding portion of the socket. For example, pin surfaces  217 A,  217 B,  217 D, and  217 E can be configured to be in flush contact with socket walls  227 A-D when pin  216  is engaged in a complete fit with socket  226 , thereby providing contact area for electrical conduction, also referred to herein as electronic transport, through an entirety of the pin surfaces  217 A-E and corresponding socket surfaces. Engaging in a complete fit between the pin  216  and the socket  226  can result in the outer bodies  212  and  222  of the separate segments  210  and  220 , establishing a flush exterior fit between the segments. 
     In some embodiments, one or more of the socket  226  and the pin  216  are configured to engage in an incomplete fit. For example, the depth  228  of the socket  226  can be greater than the depth  218  of the pin, such that engaging pin  216  into socket  226  results in pin surfaces  217 A,  217 B,  217 D, and  217 E being in flush contact with the respective sockets walls  227 A-D and pin surface  217 C being exposed to a gap space between the pin surface  217  and a portion of the outer body  222  that bounds the portion of the socket that is distal from opening  229 . 
       FIGS. 3A and 3B  illustrate orthogonal views  301 ,  350  of the tab  200 , where the separate segments  210 ,  220  comprising the tab  200  are coupled, in a complete fit of the socket  226  and pin  216  established via engaging the pin  216  with the socket  226 , to form the tab  200 , according to some embodiments.  FIGS. 4A-4D  illustrate cross sections  360 ,  370 ,  380 ,  390  of the tab  200  comprising the coupled segments  210 ,  220 , according to some embodiments. The tab  200  illustrated in  FIGS. 3A and 3B and 4A-4D  can be included in any of the embodiments of a bi-metal tab herein, including one or more of the tabs  126 A and  126 B illustrated in  FIG. 1 . 
     As shown in  FIGS. 3A and 4C-4D , the segments  210 ,  220  are coupled together, via engagement of the pin  216  of segment  210  into the socket  226  of segment  220 , forming a complete fit of the pin  216  within the socket  226 , so that the pin  216  is in flush contact with the socket walls  227 A- 227 D that bound the socket  226 . As shown, the coupled segments  210 ,  220  establish a flush coupling of the exterior surfaces of the segment  210 ,  220 , so that the tab  200  formed from the coupling of the segment  210 ,  220  includes a flush exterior at the interface  372  between the segments. 
     As shown in  FIGS. 3A and 3B , a seal  340  can be coupled to the tab  200  and can partition the exterior of the tab  200  into two isolated portions  342 A and  342 B located on opposite sides of the seal  340 . As shown in  FIG. 4C , the seal can comprise a cylindrical structure through which the tab  200  can fit, where the interior of the seal structure is in contact with the exterior surface of the tab  200 . Coupling the seal to the tab can include sliding the tab  200  through the interior  342  of the seal structure  340  and positioning the tab  200  in a particular configuration, with regard to the portion of the tab  200  enclosed by seal  340 , which results in a partitioning of the tab  200  exterior surface into two separate portions  342 A and  342 B where at least one portion  342  includes an exposed exterior that is exclusively an exposed exterior of the external tab segment of segments  210 ,  220 . In some embodiments, the other portion  342 , which does not include an exposed exterior that is exclusively an exposed exterior of the external tab segment, can include exposed exteriors of both the external tab segment and the internal tab segment. In the illustrated embodiment, the seal  340  is coupled to a portion of the tab  200  in a particular configuration that results in the seal  340  isolating the external interface  372  of the segments  210 ,  220  from being included in the exposed exterior of the tab in either portion  342 A or  342 B. 
     In addition, the illustrated configuration of seal  340  results in the exposed surfaces included in portion  342 A being restricted to exterior surfaces of socket tab segment  220  and the exposed surfaces included in portion  342 B being restricted to exterior surfaces of pin tab segment  210 . As a result, where one of the pin tab segment  210  or the socket tab segment  220  comprises an external tab segment and the other segment comprises an internal tab segment, one of the portions  342 A or  342 B that includes exposed surfaces exclusively of an interior tab segment is configured to be included within an interior of a battery cell, thereby precluding the other portion  342 A or  342 B, that includes at least exposed surfaces of an exterior tab segment, from exposure to interior components of the battery cell with that the internal metal material comprising the internal tab segment may react. 
     In some embodiments, the pin tab segment  210  is the internal tab segment, such that portion  342 B is configured to be included in an interior of a battery cell, where body  212  can be coupled to a terminal included in the interior of the battery cell, and the exposed surfaces of the exterior tab segment in portion  342 A are configured to be isolated from exposure to the interior of the cell via seal  340 . In some embodiments, the pin tab segment  210  is the external tab segment, such that portion  342 A is configured to be included in an interior of a battery cell, where body  222  can be coupled to a terminal included in the interior of the battery cell, and the exposed surfaces of the exterior tab segment in portion  342 B are configured to be isolated from exposure to the interior of the cell via seal  340 . In addition, where the pin tab segment  210  is the internal tab segment, the pin structure  216  can be located within the portion  342 A of the tab  200  that can be located within the volume of the interior of the battery cell, as the pin  216  is isolated from exposure to the interior of the battery cell via the socket walls  227  bounding the socket  226 . In addition, as noted above, the seal  240  can isolate the interface  372  between the segments  210 ,  220  from exposure to the interior of the cell. 
     In some embodiments, a battery includes a particular layer included in a bi-metal tab that at least partially restricts electronic transport through one or more battery cells, between a battery cell and an external environment, etc. based on exposure to one or more physical conditions within at least the particular layer. Such a layer is referred to herein as a “protection layer”. As referred to herein, a “protection layer” can be referred to interchangeably as a “functional layer”, a “protection layer material” comprised in the protection layer can be referred to as a “functional layer material”, and a “protection material” included in the protection layer can be referred to as a “functional material”. A battery cell can include one or more bi-metal tabs that include one or more various protection layers that are configured to restrict electronic transport between separate portion of the bi-metal tab, thereby restricting operation (e.g., charging, discharging) of the battery cell under certain conditions. 
       FIGS. 5A and 5B  illustrate a bi-metal tab  500  that includes a protection layer applied to surfaces of the pin tab segment  510 , where the protection layer separates the pin tab segment  510  and the socket tab segment  520  when the segments  510 ,  520  are coupled together and is configured to electrically isolate the coupled segments  510 ,  520  based on exposure to one or more particular physical conditions, according to some embodiments. The tab  500  illustrated in  FIGS. 5A and 5B  can be included in any of the embodiments of a bi-metal tab herein, including one or more of the tabs  126 A and  126 B illustrated in  FIG. 1 . 
     As shown in  FIG. 5A , a protection layer  530  is applied to surfaces of at least the pin structure  516  and portions of the pin outer body  512  that are configured to be in flush contact with one or more socket tab segment  520  surfaces when the segments  510 ,  520  are coupled together. In some embodiments, a protection layer  530  is applied to one or more surfaces of at least the socket  526  included in the socket tab segment  520 . In some embodiments, the dimensions of the pin  516  are less than the corresponding dimensions of the socket  526 , so that the protection layer can fit between the socket tab segment  520  and the pin tab segment  510  when the pin  516  is coupled with the socket  526 . The protection layer  530  can have dimensions that correspond to a difference between the pin  516  dimensions and the socket  526  dimensions, so that the protection layer  530  forms a connection between the pin  516  and the socket  526  when the pin  526  and the socket  530  are coupled. For example, as shown in  FIG. 5A , the total depth  528  of the socket  526  can correspond to the total depth  519  of the pin  516  to that the protection layer  530  is applied, where the depth  518  of the pin alone is less than depth  528  and the additional depth resulting from application of layer  530  to pin  516  results in a layered pin having a depth  519  that corresponds to the depth  528  of socket  526 . Similarly, the total height  537  of the socket  526  can correspond to the total height  533  of the pin  516  to that the protection layer  530  is applied, where the height  531  of the pin alone is less than height  537  and the additional height resulting from application of layer  530  to pin  516  results in a layered pin having a height  533  that corresponds to the height  537  of socket  526 . 
     As shown in  FIG. 5B , when the layered pin  516  is engaged into the socket  536 , the external surface of the layered pin can lie in flush contact with the surfaces of the socket  526 , thereby establishing a uniform connection between the segments  510 ,  520  via at least some of the surfaces of the pin  516  and the socket  526 . In some embodiments, the uniform connection is established via an entirety of the surfaces of the pin  516  and the socket  526  when the pin is engaged with the socket  526 . The resulting tab  500 , shown in  FIG. 5B , includes a protection layer that bridges a connection between the separate segments  510 ,  520 . The protection layer can include one or more instances of binder materials that can at least partially adhere the surfaces of pin tab segment  510  to the surfaces of the socket tab segment  520 . The protection layer can include one or more instances of active materials that facilitate electronic transport between the separate segments  510 ,  520 . 
     The protection layer  530  can provide adhesion of segments  510 ,  520  and can, under regular battery operating conditions, conduct electricity between the segments  510 ,  520 , thereby facilitating electronic transport. Upon exposure to one or more particular physical conditions, the protection layer  530  can at least partially restrict electronic transport across the layer  530 , thereby restricting electronic transport between segments  510  and,  520 , which can result in shutting down operation of a battery cell to that the tab  500  is coupled. In some embodiments, the layer  530  is isolated from an interior of the battery cell to that tab  500  is coupled. As a result, the layer  530  can be isolated from corruption, degradation, etc. by various materials included in the cell, including various electrolyte substances, thereby augmenting the shut-down functionality and resulting protection provided by the layer  530 . 
     The protection layer can mitigate the effects of a failure, fault, etc. of the cell, one or more conditions that can lead to a failure, fault, etc., by shutting down the cell. In particular, the protection layer can be configured to restrict electronic transport based on exposure to physical conditions that can result from one or more various failures of the battery cell. Such failures can include one or more of excessive current through the cell during charging or discharging, an electrical short, an overcharging state associated with excessive voltage, an excessive discharge state associated with an undervoltage, excessive temperature in the cell, an overheating state of the cell that is associated with one or more temperature values, an overpressure state in the cell, some combination thereof, etc. For example, the one or more conditions can include physical conditions associated with an electrical short of the battery cell, including one or more of temperature, voltage, etc. that exceeds one or more threshold values. Because the protection layer restricts electronic transport based on exposure to one or more of such physical conditions, the protection layer can shut down a battery cell that is experiencing one or more various faults. As a result, the physical effects of such a failure, fault, etc. are mitigated, thereby mitigating the risk of physical damage to elements external to the cell. 
     In some embodiments, a protection layer can conduct or restrict electronic transport across the layer, based on the physical conditions to that it is exposed, independently of the composition, phase, type, etc. of electrolytes that are present in the battery cell. For example, the protection layer  530  shown in  FIGS. 5A and 5B  can be comprised of materials that are chemically neutral, inert, etc. with regard to the one or more electrolytes that can be present in the cell to that tab  500  is coupled. In some embodiments, the protection layer  530  is electrochemically neutral. As a result, the protection layer  530  can provide a “shut down” ability for the battery that can be utilized without consideration for the type and composition of electrolytes included in the battery cell, as the protection layer  530  may operate, i.e., conduct or restrict electronic transport, independently of the electrolyte materials included in the cell. The protection layer  530  can thus provide augmented shutdown capability with respect to a battery separator layer as a result of operating independently of the various electrolytes that can be included in the battery cell. The protection layer can thereby provide at least partial shutdown of batteries that include solid electrolyte materials. In addition, the protection layer  530  can restrict electronic transport between separate battery cells via the tab  500  and can provide at least partial shutdown, electrical isolation, etc. between separate battery cells in a battery. The protection layer can thereby provide at least partial shutdown of bipolar batteries. 
     In some embodiments, the protection layer provides augmented adhesion between the separate segments  510 ,  520  of the tab  500 , reduced contact resistance between the separate segments  510 ,  520 , etc. The protection layer can be comprised of a mixture of various materials, referred to herein as the protection layer material, where at least some of the protection layer material comprises materials that provide various functions of the protection layer. The protection layer material can include one or more binder materials that provide adhesion by the protection layer between the separate tab segments  510 ,  520 . A binder material can include one or more of CMC, PVDF, Acrylic binders, some combination thereof, etc. The protection layer material can include one or more conductive materials, also referred to herein as active materials, that are electrically conductive and therefore at least partially facilitate electronic transport across the protection layer. Conductive materials can include one or more of carbon black materials, carbon nanotube materials, silver materials, etc. The protection layer material can include one or more thermally-activated binder materials that are activated based on the temperature of the binder materials exceeding one or more threshold temperatures. 
     In some embodiments, a protection layer, to restrict electronic transport across the layer based on exposure of the layer to one or more physical conditions, changes from being an electrically conductive layer to being an electrically insulating layer based on exposure to the one or more physical conditions. Physical conditions can include one or more of a temperature of at least the protection layer, a voltage of at least the protection layer, some combination thereof, etc. For example, a protection layer can change to an electrically insulating layer, thereby shutting down a battery cell, in response to exposure of at least a portion of the layer to a temperature that exceeds one or more threshold temperature values, that can include one or more of a high temperature threshold, a low temperature threshold, some combination thereof, etc. Exposure of at least one portion of a protection layer to a physical condition that comprises at least a particular temperature can include exposure of the at least one portion of the protection layer to a physical condition that causes the temperature of the at least one portion of the protection layer to be at least the particular temperature. Exposure of at least one portion of a protection layer to a physical condition that comprises at least a particular temperature can include the temperature of the at least one portion of the protection layer being at least the particular temperature. Exposure of at least one portion of a protection layer to a physical condition that comprises at least a particular voltage can include exposure of the at least one portion of the protection layer to a physical condition that causes the voltage across the at least one portion of the protection layer to be at least the particular voltage. Exposure of at least one portion of a protection layer to a physical condition that comprises at least a particular voltage can include the voltage across the at least one portion of the protection layer being at least the particular voltage. 
     To change from being electrically conductive to being electrically insulating, the protection layer can be comprised of one or more materials that, in response to exposure to one or more particular physical conditions, including one or more physical conditions that exceed one or more threshold values, change state to an electrically insulating state. Such materials are referred to herein as “protection materials”. A protection material, upon changing state to an electrically insulating state, can overcome conductivity of one or more active materials included in the protection layer, thereby rendering the protection layer as an electrically insulating layer. The change in state can be irreversible, such that the battery cell is permanently shut down. In some embodiments, the change in state is reversible, such that the battery cell can be re-started upon physical conditions to that the protection layer is exposed being within one or more threshold value ranges. 
     A change of state of a protection material in the protection layer can include a change in molecular structure of the material within the layer, including polymerization of the material, depolymerization, decomposition, some combination thereof, etc. A change of state of a material in the protection layer can include a change in phase of the material within the layer including the material changing from a solid to a gas phase. A change of state of a material can include a combination of a change in molecular structure and a change in phase; for example, a material can, based on a local temperature of the material, decompose into one or more different substances that are in a different phase, which can result in outgassing from the material within the layer. Where a material changes molecular structure, composition, phase, some combination thereof, etc., the resulting one or more materials, in the one or more resulting phases, can be electrically insulating and can, in some embodiments, overcome one or more electrically conductive materials in the protection layer such that the protection layer becomes electrically insulating. Such overcoming of conductive materials can include the resulting one or more insulating materials terminating some or all electrically conductive pathways through the protection layer. 
     In some embodiments, a protection layer comprises various protection materials that each change to an electrically insulating state in response to different physical conditions. A protection layer can comprise a mixture of multiple different materials, where one or more materials change to an electrically insulating state in response to a local temperature of the material exceeding a particular threshold value and one or more different materials change to an electrically insulating state in response to a local voltage exceeding a particular threshold value and one or more different materials change to an electrically insulating state in response to the local voltage exceeding a different particular threshold value. 
     For example, a protection layer can include a protection material that is stable within a certain range of exposed temperatures, including a range from −40 degrees Celsius to +80 degrees Celsius, and changes state to an electrically insulating state upon exposure to a temperature beyond that range. Such a material can include one or more various polymers, additives, some combination thereof, etc., including, for example, Li 2 CO 3 . Such a protection material can respond to exposure to a physical condition beyond a certain range or threshold value by changing state, including expanding, decomposing, generating gases, some combination thereof, etc. In some embodiments, a protection layer includes a protection material that is stable when exposed to a temperature that is below a certain threshold temperature and changes state to an electrically insulating state upon exposure to a temperature above that certain threshold temperature. In some embodiments, a protection layer includes a protection material that is stable when exposed to a temperature that is above a certain threshold temperature and changes state to an electrically insulating state upon exposure to a temperature below that certain threshold temperature. 
     In another example, a protection layer can include a protection material that is stable within a certain range of exposed operating voltages, including a range from 3.0 volts to 4.4 volts, and changes state to an electrically insulating state upon exposure to a voltage beyond that range. Such a material can include one or more various substances, additives, some combination thereof, etc., including, for example, Biphenyl. Such a protection material can respond to exposure to a physical condition beyond a certain range or threshold value by changing state, including expanding, decomposing, generating gases, some combination thereof, etc. In some embodiments, a protection layer includes a protection material that is stable when exposed to an operating voltage that is below a certain threshold operating voltage and changes state to an electrically insulating state upon exposure to a voltage above that certain threshold operating voltage. In some embodiments, a protection layer includes a protection material that is stable when exposed to an operating voltage that is above a certain threshold operating voltage and changes state to an electrically insulating state upon exposure to a voltage below that certain threshold operating voltage. 
     A protection layer can comprise a mixture of various protection materials, some of that are configured to change to an electrically insulating state based on exposure to different sets of one or more physical conditions. Protection materials that change to an electrically insulating state in response to one or more physical conditions can be included in one or more “additive” materials that can be included in the mixture of materials comprising the protection layer material. In some embodiments, the additive materials comprise a minority portion of the mixture of materials comprising the protection layer material. For example, a protection layer can be comprised of a mixture of one or more additive materials, where each additive material comprises approximately 5-10% of the mixture by one or more of mass, volume, etc. In another example, a protection layer can be comprised of a mixture of one or more additive materials that collectively comprise approximately 5-10% of the mixture by one or more of mass, volume, etc. In another example, a protection layer can be comprised of a mixture of one or more additive materials, where each additive material comprises approximately 5-10% of the mixture by one or more of mass, volume, etc., one or more binder materials that comprise approximately 5-10% of the mixture by one or more of mass, volume, etc., and mixture of one or more active materials that comprise a remainder of the mixture by one or more of mass, volume, etc. In some embodiments, the protection layer comprises a slurry of various materials, including one or more active materials, protection materials, binder materials, etc. that is applied to one or more surfaces of one or more layers of a battery cell to form the protection layer. 
     In some embodiments, the protection layer  530  comprises a mixture of one or more protection materials, as described above, that are configured to change to an electrically insulating state based on at least some of the protection layer  530  being exposed to one or more physical conditions, that can include physical conditions that exceed one or more physical condition thresholds. As a result, the protection layer  530  can, based on at least the layer  530  being exposed to one or more particular physical conditions, restrict electronic transport through the tab  500 , and therefore between a terminal of a battery cell and an exterior of the cell. Such restricting of electronic transport can result in a shutting down of discharging, charging, etc. of a battery cell, which can mitigate a catastrophic failure of a battery that could result in physical damage to an exterior environment that is external to the battery. 
     In some embodiments, a pin structure included in a pin tab segment extends along an entirety of at least one dimension of the pin, so that the pin is at least partially exposed when the pin is coupled to a corresponding socket of a corresponding socket tab segment.  FIGS. 6A-6C  illustrate a bi-metal tab  600  that includes a pin tab segment  610  and a socket tab segment  620 , according to some embodiments. As shown in cross-sectional view  650  illustrated in  FIG. 6C , the pin tab segment  610  extends along a width  601 , and the pin structure  616  included in the segment  610  extends along a common width  601  as the outer body  612  of the pin tab segment. 
     The corresponding socket tab segment  620  includes a corresponding socket  626  that extends along a common width  601  as the outer body  622  of the socket tab segment  620 . The socket  626  and the pin  616 , in some embodiments, extend along a common width  601 . As shown in  FIG. 6A , the socket  626  is bounded on two opposite sides by socket walls  627 A and  627 B. Because the socket  626  extends along the same length of width dimension  601  as the socket outer body  622 , the docket  626  is unbounded on two opposite sides that are orthogonal to the sides bounded by walls  627 A and  627 B. 
     As further shown in  FIG. 6A , the height  633  of pin  616  can correspond to the height  637  of socket  626 , and the depth  628  of socket  626  can correspond to the depth  618  of pin  616 , so that the socket  626  is configured to couple with the pin  616  in a flush fit, and the pin  616  is configured to couple with the socket  626  in a flush fit. The height  631  of the pin outer body  612  can correspond to the height  635  of the socket outer body  622 , so that the tab  600  includes a flush outer surface when the segments  610 ,  620  are coupled in a flush fit between the pin  616  and the socket  626 . 
     As shown in  FIGS. 6B-6C , when the pin tab segment  610  and the socket tab segment  620  are coupled, via engagement, insertion, etc. of the pin  616  into the socket  626 , at least one surface  617  of the pin  616  is exposed to an exterior environment of the tab  600 . As shown, because the width of the pin  616 , the socket  626 , and the outer bodies  612 ,  622  are common, and the sides of the socket  626  on opposite sides of the width  601  of the segment  622  are unbounded by socket walls  627 A and  627 B, the opposite side surfaces  617 A and  617 B of the pin remain exposed when pin  616  is inserted into socket  626 , while surfaces of pin  6161  that are orthogonal to surfaces  617 A and  617 B are bounded by socket walls  627 A and  627 B, to that the orthogonal surfaces are coupled extends along a common width  601  as the outer body. As a result, the tab  600  is configured to facilitate electronic coupling across the surfaces of the pin  616  that are engaged in contact with the socket tab segment  622 . 
     As shown in  FIG. 6B , tab  600  can include a seal  640  that is coupled to the tab  600  so that the seal  640  extends around the exterior of the tab  600  and separates the exposed portions of the tab into two portions  642 A and  642 B that are separated by the seal  640 . The seal can be incorporated into an exterior surface of a battery cell, so that the seal  610  isolates one portion  642  that is internal to the battery cell from another portion  642  that is external to the battery cell. In some embodiments, where the pin tab segment  610  is comprised of an external metal material and the socket tab segment  620  is comprised of an internal metal material, the seal  640  is coupled to the tab  600  at a position that isolates any exposed portion of pin tab segment  610 , including the exposed surfaces  617 A and  617 B of pin  616 , from being included in a portion  642 A that is configured to be included in an interior of a battery cell. For example, as shown in  FIG. 6B , the seal  640  is coupled to the tab  600  at a position that separates the tab  600  into a portion  642 A that includes the exposed material of segment  620  and a separate portion  642 B that includes the exposed materials of both segments  610  and  620 . The illustrated configuration of seal  640  can be implemented where the pin tab segment  610  is comprised of an external metal material and the socket tab segment  620  is comprised of an internal metal material, as the illustrated configuration of seal  640  isolates the external material comprising segment  610  from being exposed in at least one isolated portion,  642 A, that can be included in the interior of a battery cell. In some embodiments, where the socket tab segment  620  is comprise do internal metal material, the seal  640  can be coupled to the tab  600  in a configuration that separates the exposed portions of the tab  600  into a portion  642 A that includes exposed surfaces of segments  610 ,  620  and is configured to be included on an exterior of a battery cell and an isolated portion  642 B that includes exposed surfaces of segment  610  and is configured to be included in an exterior of a battery cell, where the exposed surfaces of segment  620  are isolated from portion  642 B. 
     Those skilled in the art will appreciate that a number of techniques may be used to fabricate a battery, including a lithium battery that includes at least one bi-metal tab according to any of the embodiments included herein. In some embodiments, a battery that is configured to at least partially suppress electronic transport through one or more battery cells, between one or more battery cells and one or more portions of a battery, etc. based on one or more physical conditions at a protection layer included in one or more bi-metal tabs included in one or more battery cells, can be at least partially fabricated via various techniques. One or more various processes for fabrication of a bi-metal tab can be implemented, as shown and described below. 
       FIG. 7  illustrates a fabrication system configured to fabricate a bi-metal tab, according to some embodiments. The fabricating can be controlled by one or more computer systems, which are described further below. 
     The system  700  can include a mixing process  710  where various protection layer materials are received and mixed to form a protection layer material that is applied to one or more surfaces of one or more tab segment. A pin tab segment and a socket tab segment, and one or more protection layers can be applied at step  722  to one or more surfaces of one or more of the segments pin tab and socket tab segments. 
     Each separate segment can be comprised of a separate metal material, where one material is configured to resist corrosion in an interior of a battery cell and is referred to as the internal metal. A segment that is comprised of the internal metal can be referred to as the internal tab segment, and the other segment, which can be comprised of a separate metal material can be referred to as the external tab segment. In some embodiments, the pin tab segment is the internal tab segment and the socket tab segment is the external tab segment. In some embodiments, the pin tab segment is the external tab segment and the socket tab segment is the internal tab segment. 
     Process  720  can include applying a protection layer to one or more surfaces of one or more of a pin tab segment and a socket tab segment. The process  720  can further include curing  724  the applied one or more layers. 
     The protection layer material formed in process  710  can include a mixture of a particular selection of the protection layer materials received at the process  710 . The mixture can include a slurry mixture that is formed via a slurry mixing process comprised within process  710 . In some embodiments, the layer applied at  722  can include multiple protection layers, and some protection layers can include separate protection layers that are comprised of different sets of materials and are configured to respond differently to different physical conditions. Processes  710 - 720  can be controlled by one or more computer systems via one or more communication links. In some embodiments, separate processes  710 - 720  are controlled by separate computer systems via separate communication links. 
     In some embodiments, one or more sets of protection layer materials used to form one or more components of one or more protection layers are provided to mixing process  710  as material stock, including a power stock, liquid stock, gaseous stock. At least some of the material can be provided as bulk material that is mixed, in separate amounts, in process  710  to form one or more batches of protection layer material that is provided, in one or more processes  720 , to form one or more protection layers on one or more surfaces of one or more of a pin segment and a socket segment. 
     The protection layer materials provided to the mixing process  710  can include on or more active materials, also referred to as conductive materials, that can facilitate electronic transport, one or more binder materials, and one or more protection materials that are configured to change state based at least in part upon being exposed to one or more physical conditions. Multiple different protection materials can be received, and one or more of the received materials can be mixed together, in process  710 , to form a protection layer material that can be provided to processes  720  to form a protection layer that can restrict electronic transport based on the layer being exposed to one or more different physical conditions. For example, one material that is received can include a material, including Li 2 CO 3  that changes state to an electrically-insulating state in response to being exposed to a physical condition that causes a temperature of the material to exceed one or more thresholds, including a temperature that is beyond a particular range or “window” of temperature values. In another example, one material that is received can include a material, including Biphenyl, that changes state to an electrically-insulating state in response to being exposed to a voltage that exceeds one or more thresholds, including a voltage that is beyond a particular range or “window” of voltage values. 
     The above protection layer materials, in some embodiments, can be mixed together in process  710  to form a mixture that, when applied in processes  720  to form one or more protection layers, form one or more protection layers that can at least partially restrict electronic transport across the layer in response to one or more of temperature or voltage within, across, etc. the one or more protection layers exceeding one or more threshold values. In some embodiments, separate materials can be mixed into separate mixtures that are provided to processes to form different protection layers; for example, Li 2 CO 3  can be mixed into a first mixture that is provided to process  720  to form a first protection layer and Biphenyl can be mixed into a second mixture that is provided to process  720  to form a second protection layer. 
     In some embodiments, one or more protection layer materials formed at process  710  are provided to protection layer application process  720  to form one or more protection layers on one or more surfaces of one or more tab segments. Such application processes can result in a layer that includes multiple protection layers that are applied to different surfaces of one or more of the tab segments, multiple protection layers applied in sequence to one or more particular surfaces of one or more tab segments, some combination thereof, etc. For example, a particular protection layer material can be applied to one or more surfaces of a pin included in the pin tab segment, and a separate protection layer material can be applied to one or more surfaces of a socket included in the socket tab segment. As a result, the multiple protection layers can be applied separately in separate application processes. 
     At  730 , a bi-metal tab  740  is fabricated from coupling at least one pin tab segment and at least one socket tab segment. The coupling can include inserting a pin included in the pin tab segment into a socket included in the socket tab segment, securing the pin in the socket via one or more known bi-metal bonding processes, coupling a seal structure to a portion of the bi-metal tab that separates the tab  740  into two separate portions, where the internal metal material is absent from being exposed on one of the separate portions. 
       FIG. 8  illustrates a fabrication system  800  configured to fabricate a battery, according to some embodiments. The fabricating can be controlled by one or more computer systems, which are described further below. 
     A set of battery components are received into a battery cell fabrication process at step  812 , where the components are assembled to form one or more battery cells. Battery components can include one or more bi-metal tabs. Battery components can also include one or more battery electrode layers, collector layers, battery separator layers, and electrolyte materials. In some embodiments, one or more of the current collector layers comprises a foil layer coupled to a terminal. In some embodiments, one or more of the bi-metal tabs includes one or more of the tabs  740  fabricated in the processes shown in  FIG. 7 . The electrolyte materials can include one or more of a solid electrolyte layer, a liquid electrolyte material, some combination thereof, etc. It will be understood that various other materials can be received into the battery cell fabrication process  810 . 
     In some embodiments, fabrication process  810  includes coupling or joining one or more tab segments together to form a bi-metal tab at step  814 . Coupling or joining one or more tab segments together may include, for example, positioning a pin segment at least partially within a socket segment and joining the pin segment with the socket segment, for example by lamination, press-fitting, or any other suitable coupling method as will be apparent to one having ordinary skill in the art. In some examples of cell fabrication process  810 , one or more protection layers may be applied to one or more of various surfaces of tabs or tab segments. 
     Some embodiments include coupling one or more bi-metal tabs to one or more terminals included in one or more current collectors, at step  816 . Coupling a bi-metal tab to a terminal can include one or more of coupling an internal portion of the bi-metal tab to a portion of the terminal, coupling a battery cell seal to a portion of the tab that separates the external portion of the tab from the interior of a battery cell in that the portion of the terminal is included, etc. 
     In some embodiments, one or more of the battery components is received as a complete layer that can be applied, in the process  810 , to at least partially assemble a battery cell via stacking the complete layer onto another layer. For example, the current collectors can be received as complete current collector layers, each comprising a particular amount of foil layer coupled to a terminal, which can be applied to an electrode layer, including a cathode layer, that is received as an electrode material, such that process  810  does not include forming the separate electrode layer and current collector. In some embodiments, one or more of the battery components are obtained as a set of materials that can be used to form one or more layers of the battery as part of process  810 . For example, one or more of the electrode materials can be received as a roll of layer material that can be cut, segmented, partitioned, etc. as part of the fabrication process  810  to form an individual electrode layer for an individual battery cell. In another example, the electrolyte material of an electrolyte layer, including LiPON, one or more additional materials, including PVDF binders, CMC binders, Acrylic binders, etc., can be obtained as a mass of material stock that can be applied to one or more surfaces, that can include a surface of one or more other layers of the battery cell, as described further below, to form one or more electrolyte layers. In some embodiments, obtaining the electrode materials includes obtaining an anode material that is used to form one or more anodes of the battery, where the anode material comprises lithium metal. 
     The battery cell fabrication process  810 , which can be controlled by computer via a communication link, produces one or more battery cells as an output, based on fabricating the cells from the components received into the process  810 . As further shown, the one or more cells can be received into a battery fabrication process  830 , which can be controlled by one or more computers via one or more communication links, and which fabricates a battery from at least the battery cells. For example, process  830  can include assembling separate battery cells into a symmetrical configuration of the cells to form a battery, for example at step  834 . In some embodiments, process  830  includes applying one or more protection layers between cells within a battery (step  836 ) as an input into the process, where the fabrication of the battery includes applying a protection layer to a foil layer of at least one battery cell and coupling the battery cell to another battery cell, so that the protection layer lies between foil layers of the separate cells. In some embodiments, the fabrication process  830  produces a bipolar battery. 
     The fabrication process  830  can include coupling an external portion of one or more bi-metal tabs included in a battery cell to one or more other portions of the battery at step  832 . For example, where the battery includes a bus bar, fabrication  830  can include coupling one or more bi-metal tabs included in a battery cell to the bus bar, which can result in electrically coupling at least one terminal of the battery cell to one or more various portions of the battery. 
     Processes  810  and  830 , in some embodiments, are controlled by separate computers via separate communication links. 
     The methods described herein may be implemented in software, hardware, or a combination thereof, in different embodiments. In addition, the order of the blocks of the methods may be changed, and various elements may be added, reordered, combined, omitted, modified, etc. Various modifications and changes may be made as would be obvious to a person skilled in the art having the benefit of this disclosure. The various embodiments described herein are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, for example, plural instances may be provided for components described herein as a single instance. Other allocations of functionality are envisioned and may fall within the scope of claims that follow. Finally, structures and functionality presented as discrete components in the example configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of embodiments as defined in the claims that follow.

Metadata:
Filing Date: 20160407
Publication Date: 20190827
Grant Date: 20190827
Priority Date: 20150407
Inventors: ZENG, Qingcheng
DAFOE, DONALD G.
CHU, ANDREW
HARVEY, ASHLEY S.
JIANG, JUNWEI
Assignee: APPLE INC
CPC Classifications: [{"code": "H01M50/186", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M50/176", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/553", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/55", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/534", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M2220/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M2/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M2/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M2220/30", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M50/534", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/553", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/55", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/186", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/176", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/571", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/578", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/581", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/052", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y02E60/10", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 67700573