PATENT DOCUMENT

Publication Number: US-10033029-B2
Application Number: US-201314041773-A
Country: US
Kind Code: B2

Title: Battery with increased energy density and method of manufacturing the same

Abstract:
A battery core includes an anode electrode collector and a cathode current collector. The battery core is created by defining an anode solution cavity on an anode electrode collector; defining a cathode solution cavity on a cathode electrode collector; depositing an anode solution into the anode solution cavity; depositing a cathode solution into the cathode solution cavity; curing the anode solution within the anode solution cavity; and curing the cathode solution within the cathode solution cavity. The anode electrode collector and the cathode current collector may be combined in a sandwich configuration and may be separated by one or more separators.

Claims:
We claim: 
     
       1. A method for creating a battery core, comprising:
 forming an anode solution cavity on an anode electrode collector; 
 forming a cathode solution cavity on a cathode electrode collector by bending or folding edges of the cathode electrode collector to form a first flow barrier wall around a perimeter of the cathode electrode collector; 
 depositing an anode solution into the anode solution cavity; 
 depositing a cathode solution into the cathode solution cavity; 
 curing the anode solution within the anode solution cavity; and 
 curing the cathode solution within the cathode solution cavity. 
 
     
     
       2. The method of  claim 1 , wherein the anode solution cavity is formed by a second flow barrier wall operably connected to the anode electrode collector. 
     
     
       3. The method of  claim 2 , further comprising etching the first flow barrier wall after curing the cathode solution. 
     
     
       4. The method of  claim 2 , wherein the second flow barrier wall is formed by bending or folding a portion of the anode electrode collector. 
     
     
       5. The method of  claim 2 , wherein the second flow barrier wall is formed during an injection molding or masking process. 
     
     
       6. The method of  claim 2 , wherein the second flow barrier wall is ring-shaped. 
     
     
       7. The method of  claim 1 , further comprising encapsulating at least one of the cured anode solution or the cured cathode solution. 
     
     
       8. The method of  claim 7 , wherein said encapsulating at least one of the cured anode solution or the cured cathode solution further comprises encapsulating the at least one of the cured anode solution or the cured cathode solution utilizing at least one polymer. 
     
     
       9. The method of  claim 1 , further comprising combining the anode electrode collector and the cathode electrode collector. 
     
     
       10. The method of  claim 9 , wherein said combining the anode electrode collector and the cathode electrode collector further comprises inserting at least one separator between the anode electrode collector and the cathode electrode collector. 
     
     
       11. The method of  claim 1 , wherein at least one of the anode electrode collector or the cathode electrode collector have a shape that generally matches a surface of a device where a battery including the battery core is inserted. 
     
     
       12. The method of  claim 11 , further comprising molding the at least one of the anode electrode collector or the cathode electrode collector to have the shape. 
     
     
       13. The method of  claim 12 , wherein at least one of the anode solution cavity or the cathode solution cavity is formed during the molding. 
     
     
       14. The method of  claim 12 , wherein at least one of the anode solution cavity or the cathode solution cavity is formed after the molding. 
     
     
       15. The method of  claim 1 , wherein the anode solution cavity prevents the anode solution from flowing off at least one edge of the anode electrode collector. 
     
     
       16. The method of  claim 1 , further comprising removing at least one of excess anode solution from the anode solution cavity or excess cathode solution from the cathode solution cavity. 
     
     
       17. The method of  claim 1 , wherein at least one of said curing the anode solution or curing the cathode solution comprises at least one of heating or baking. 
     
     
       18. The method of  claim 1 , wherein the cathode solution cavity prevents the cathode solution from flowing off at least one edge of the cathode electrode collector. 
     
     
       19. A battery core, comprising:
 an anode electrode collector including a cured anode solution deposited in an anode solution cavity; 
 a cathode electrode collector, indirectly coupled to the anode electrode collector via a separator, including a cured cathode solution deposited in a cathode solution cavity; wherein: 
 the anode electrode collector has bent or folded edges around a perimeter of the anode electrode collector forming a first barrier flow wall around the anode solution cavity and/or the cathode electrode collector has bent or folded edges around a perimeter of the cathode electrode collector forming a second barrier flow wall around the cathode solution cavity.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 61/730,263, filed Nov. 27, 2012, entitled “Battery with Increased Energy Density and Method of Manufacturing the Same,” the entirety of which is incorporated by reference as if fully recited herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to batteries, and more specifically, to rechargeable batteries and methods of manufacturing rechargeable batteries. 
     BACKGROUND 
     Many components, especially electronic devices such as laptops, tablet computers, smart phones, and the like, use rechargeable batteries to provide power to one or more electronic components. A number of electronic devices may use lithium ion batteries as the power source as lithium ion batteries generally have an increased energy density (watts/liter) as compared to other types of batteries. However, as electronic components are become smaller, the current structure of the lithium ion batteries may limit the energy density that may be available for a particular size. For example, some lithium ion batteries are constructed in a “jelly roll” configuration where the anode and cathode are placed on a substrate, which is then rolled around itself to create the jelly roll. The jelly roll may then be placed within a pouch, which may be generally rectangular or square. In these configurations, portions of the internal cavity of the pouch may be wasted space, as the curved jelly roll may not fit tightly within the pouch. Thus, current lithium batteries may not have the maximum energy density for a particular size, as some of the space within the pouch may go unused. 
     As electronic components decrease in size, and subsequently the lithium ion batteries also decrease in size, the unused space defined within the pouches may represent a higher percentage of the total size of the lithium ion battery space. 
     SUMMARY 
     In some embodiments herein, a battery and a method for manufacturing the battery are disclosed. The battery may include stacked layers that may form the components of the battery (e.g., anode, cathode). In some embodiments, the stacked configuration may not have to be “rolled” together. Accordingly, the battery configuration may have little or no unused space when positioned within a cell or pouch, which may allow the battery to have an increased energy density for a similarly sized conventional jelly roll lithium ion battery. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front plan view of an illustrative electronic device incorporating a battery of the present disclosure. 
         FIG. 2  is a front plan view of the electronic device with a top portion of the enclosure removed to illustrate the batteries within the enclosure cavity. 
         FIG. 3A  is a cross-section view of one of the batteries illustrated in  FIG. 2  taken along line  3 - 3  in  FIG. 2 . 
         FIG. 3B  is a cross-section view of one of the batteries including a protective or encapsulant around an anode and a cathode. 
         FIG. 4  is a flow chart illustrating a method for manufacturing the batteries of  FIG. 2 . 
         FIG. 5A  is a top plan view of one of the elector collectors operably connected to one of the flow barriers. 
         FIG. 5B  is a simplified exploded view of the collector and the flow barrier. 
         FIG. 6A  is a top plan view of the electrode collector and the flow barrier with the anode or cathode solution received into the solution cavity. 
         FIG. 6B  is a cross-section view of the electrode collector and the flow barrier taken along line  6 B- 6 B in  FIG. 6A . 
         FIG. 7A  is a schematic view of excess anode solution being scraped from the top of the solution cavity. 
         FIG. 7B  is a schematic view of excess cathode solution being scraped from the top of the solution cavity. 
         FIG. 8A  is a schematic view of the anode solution being hardened within the solution cavity by being heated. 
         FIG. 8B  is a schematic view of the cathode solution being hardened within the solution cavity by being heated. 
         FIG. 9A  is a schematic view of the anode encapsulant being formed around the anode solution. 
         FIG. 9B  is a schematic view of the cathode encapsulant being formed around the cathode solution. 
         FIG. 10A  is a schematic view of an electrolyte being added to the anode prior to the anode being operably connected to the cathode. 
         FIG. 10B  is a schematic view of a separator being operably connected to the cathode prior to the cathode being operably connected to the anode. 
         FIG. 11  is a schematic view of the assembled battery core including an anode and a cathode having an increased thickness. 
         FIG. 12A  is a schematic view of an alternative manufacturing operation including adding an electrolyte layer. 
         FIG. 12B  is a schematic view of a lithium metal layer being applied on a top of the electrolyte layer from  FIG. 12A . 
         FIG. 12C  is a schematic view of an alternative embodiment of the battery core including the lithium metal layer formed on top of the electrolyte layer. 
         FIG. 13  is a simplified cross-section view of a cathode layer including an electrode collector molded to conform to a surface. 
     
    
    
     DETAILED DESCRIPTION 
     The anode layer and a cathode layer of the battery may each have an increased thickness as compared to the anode and cathode layers for conventional lithium ion batteries. The increased thickness may provide an increase in efficiency of the battery with respect to the electrode potential of the cathode. This is because generally the electrode potential for the battery may related to the volume of the cathode as compared to the total volume of the cell. For example, energy density is generally watts per liter, and the volume of the cathode may be a proxy for watts, such that as the cathode fills more of the total cell volume (e.g., liters), the more watts may be produced by the cell. Additionally, the increased thickness may provide an increase in energy density as more of the volume of the battery cell may be dedicated to energy providing components, e.g., the anode and cathode. 
     In conventional lithium ion batteries, the thickness of the cathode and/or anode may be limited due to liquid or partially liquid form of the cathode and/or anode solutions when they are applied to the substrate or electrode collectors. For example, in many instances the cathode and anode solutions or mixtures may be applied to a substrate (e.g., electrode collector) in a “slurry” or partially liquid form. This liquid form may restrict the thickness of the application of the material on the substrate as prior to curing the slurry may roll or slide off of the substrate as the thickness is increased. 
     In some embodiments of the present disclosure, flow barriers and/or encapsulation walls may be used during manufacturing to provide a barrier to prevent the cathode and anode solutions from rolling off of the substrate. This manufacturing method may allow the cathode and anode solutions to be applied in thicker layers, which as mentioned above, may increase the energy density of the battery cell. For example, the flow barriers may include one or more walls extending above the substrate or may include one or more wells formed into the substrate and act to retain the anode or cathode slurries (e.g., LiCo slurry) within a solution cavity or well. 
     In some embodiments, the flow barriers may be defined by a mask on the substrate of either the cathode or anode. In other embodiments, the flow barriers may be defined by a ring-shaped wall or otherwise defined so as to provide a well or void space on top of the cathode base that can receive the anode and/or cathode solution slurries. The wall or barrier may removable after the slurry has hardened or may remain in position when the battery is assembled. The wall or barrier may be formed of a variety of materials which may be selected based on whether the wall or barrier may be removed. For example, in embodiments where the wall or barrier may be removable, the material selected may be easily etched or peeled away, but strong enough to retain the slurry on top of the substrate. 
     Once the flow barrier walls have been created, the anode and cathode mixtures may be poured or injected into a solution cavity or well defined by the flow barriers. Once the anode and cathode solutions are received into the solution cavity or well, the solutions may be baked or otherwise cured, with the flow barriers substantially preventing the slurries from escaping the solution cavity during baking. In other words, the flow barriers may substantially prevent the anode and cathode slurries from flowing off of the edge of a substrate or electrode collector. After the solutions have hardened, one or more protective walls or encapsulates may be formed around the anode and cathode. With the encapsulates in position, the anode and cathode may be combined in a sandwich configuration, with a separator positioned therebetween. 
     In other embodiments, the electrode collector or substrate may have a shape selected to generally match a surface where the battery may be inserted, e.g., a bottom surface of an enclosure for an electronic device. In these embodiments, the anode and/or cathode slurry may be injected into the cavity defined by the cured substrate. In these embodiments, the barrier or wall may be formed by the substrate as the substrate is molded. However, in other embodiments, the substrate may be molded to correspond to a surface of the enclosure of the device and a separate wall or barrier may be operably connected thereto (e.g., two shot injection molding process where a first injection shot forms a substrate and a second injection shot forms the barrier wall), which may then be used to contain the slurry. 
     Turning now to the figures, an illustrative electronic device incorporating the battery will be discussed in further detail.  FIG. 1  is a front plan view of an electronic device  100  incorporating one or more batteries.  FIG. 2  is a front plan view of the electronic device  100  with a top enclosure and/or display removed. The electronic device  100  may include an enclosure  102 , a screen  104 , and/or one or more input/output buttons  106 . The electronic device  100  may be substantially any type of electronic device, such as, but not limited to, a tablet computer, a laptop computer, a smart phone, a gaming device, or the like. The electronic device  100  may also include one or more internal components (not shown) typical of a computing or electronic device, such as, but not limited to, one or more processors, memory components, network interfaces, and so on. 
     The display  104  may be operably connected to the electronic device  100  or may be communicatively coupled thereto. The display  104  may provide a visual output for the electronic device  100  and/or may function to receive user inputs to the electronic device  100 . For example, the display  104  may be a multi-touch capacitive sensing screen that may detect one or more user inputs. 
     As shown in  FIG. 1 , the enclosure  102  may form an outer surface and protective case for the internal components of the electronic device  100  and may at least partially surround the display  104 . The enclosure  102  may be formed of one or more components operably connected together, such as a front piece and a back piece, or may be formed of a single piece operably connected to the display  104 . With reference to  FIG. 2 , in some embodiments, the enclosure  102  may have a bottom surface  118  surrounded by an exterior wall  120  defining an enclosure cavity  108 . The enclosure cavity  108  may be enclosed by a front portion of the enclosure (not shown) and/or the display  104 . In these embodiments, the enclosure cavity  118  may be substantially sealed from the outer environment and provide a housing for one or more components of the electronic device  100 . 
     In some embodiments, one or more battery cells  110 ,  112  may be received within the enclosure cavity  108  and operably connected to the enclosure  102 . Although two battery cells  110 ,  112  are shown in some embodiments, the electronic device  100  may include only one battery cell  110 ,  112  or may include three or more battery cells. Additionally, each battery cell  110 ,  112  may be substantially the same or the battery cells may be different from each other (e.g., different sizes, energy densities, or types). It should be noted that although the battery cells  110 ,  112  are illustrated in  FIG. 2  as being generally rectangular, many other dimensions and shapes are envisioned, such as but not limited to, geometric, non-geometric, or the like. 
     Each battery cell  110 ,  112  may provide power to one or more components of the electronic device  100 .  FIG. 3A  is a simplified cross-section view of one of the battery cells  110 ,  112  taken along line  3 - 3  in  FIG. 2 . It should be noted the battery cells  110 ,  112  may have similar internal components and so although the following discussion is made with respect to a first battery cell  110 , it is equally applicable to the second battery cell  112 . Each battery cell  110 ,  112  may include a housing  114  or pouch and a battery core  122 . The housing  114  may generally enclose the battery core  122  and provide some protection and structure for the battery core  122 . 
     A positive terminal  124  and a negative terminal  126  may extend through the housing  114  or otherwise be in communication with the battery core  122  while also being configured to be in communication with one or more external components (e.g., components of the electronic device  100 ). The terminals  124 ,  126  may transfer current from the battery core  122  to one or more components of the electronic device  100 , as well as may transfer current to the core  122  from an external power source (such as when the battery cells  110 ,  112  are being charged). 
     A cathode electrode collector  134  may be in communication with the positive terminal  124 . The cathode electrode collector  134  may be an electrically conductive material, such as aluminum. The cathode electrode collector  134  may be a relatively thin piece of material, such as an aluminum foil. The cathode electrode collector  134  may form a substrate or base on which a cathode  130  may be positioned. 
     The cathode  130  or positive electrode may be a layered oxide, such as lithium cobalt oxide (LiCoO 2 ), a polyanion, such as lithium iron phosphate, or a spinel, such as lithium manganese oxide. As will be discussed in more detail below, the cathode  130  may include a solution  131  having an active material (e.g., LiCoO 2 ), a conductive additive (e.g., carbon black, acetylene black, carbon fibers, graphite, etc.), a binder (such as polyvinylidene fluoride, ethylene-propylene, and a diene), and optionally a solvent. The binder acts to hold the active material and the conductive additive together, and in instances where the binder is non-water soluble the solvent (which may be a such as N-methypyrrolidone), acts to distribute the active material and conductive additive throughout the binder. It should be noted that the above examples of the cathode solution  131  are meant as illustrative only and many other conventional cathode materials may be used to form the cathode. 
     An anode electrode collector  132  may be in communication with the negative terminal  126 . The anode electrode collector  132  may be a generally conductive material, such as copper. The anode electrode collector  132  may form a base or substrate for an anode  128 . Similarly to the cathode electrode collector  134 , the anode electrode connector  132  may be a relatively thin and/or flexible piece of material, such as a copper foil. 
     The anode  128  or negative electrode is generally the source of ions and electrons for the battery core  122 . The anode  128  may include an anode solution  129  including an active material (e.g., lithium, graphite, hard carbon, silicon, or tin), a conductive additive (e.g., carbon black, acetylene black, or carbon fibers), a binder (such as polyvinylidene fluoride, ethylene-propylene, and a diene), and optionally a solvent. 
     A separator  136  may be positioned between the cathode  130  and the anode  128 . The separator may be a fiberglass cloth or flexible plastic film (e.g., nylon, polyethylene, or polypropylene). The separator  136  separates the anode  128  and cathode  130  while allowing the charged lithium ions to pass between the anode  128  and cathode  130 . 
     An electrolyte (not shown), which may be a mixture of organic carbonates such as ethylene carbonate or diethyl carbonate containing complexes of lithium ions. These non-aqueous electrolytes generally use non-coordinating anion salts such as lithium hexafluorophosphate (LiPF 6 ), lithium hexafluoroarsenate monohydrate (LiAsF 6 ), lithium perchlorate (LiClO 4 ), lithium tetrafluoroborate (LiBF 4 ), and lithium triflate (LiCF 3 SO 3 ). The electrolyte may be filled into the anode  128  and/or cathode  130  around the anode and cathode solutions  129 ,  131 . In some embodiments, the electrolyte may be saturated into the separator, such that as the separator is added to the core  122 , the electrolyte may be added as well. 
     In some embodiments, the battery cells  110 ,  112  may include one or more flow barriers and/or encapsulation walls operably connected to either or both the cathode electrode collector  134  and the anode electrode collector  132 .  FIG. 3B  is a simplified cross-section view of the battery cells  110 ,  112  with the housing  114  hidden for clarity. With reference to  FIG. 3B , an encapsulation wall  159  may be operably connected to the cathode electrode collector  134 . The cathode encapsulate  159  may span between the cathode electrode collector  134  and the separator  136 . However, in some embodiments, the cathode encapsulate  159  may terminate prior to reaching the separator  136 . 
     The cathode encapsulate  159  may bound either side of the cathode  130  and thus may contain the active material, the binder, and the conductive additive. In many embodiments, the encapsulate  159  may be formed during manufacturing and may replace one or more flow barriers that contain the cathode solution  131 , this is discussed in more detail below with respect to  FIG. 4 . 
     An anode encapsulate  158  may be operably connected to the anode electrode collector  132  and may extend between the anode electrode collar  132  and the separator  136 . Similarly to the cathode encapsulate  159 , the anode flow encapsulate  158  may bound either side of the anode  128  and may be substantially any material that can prevent the anode  128  material from extending over the edges of the anode electrode collector  132 . The anode encapsulate  158  may extend along the entire height or thickness of the anode  128  such that it abuts the separator  136  or may only extend along a portion of the length of the anode  128  and terminate prior to the bottom surface of the separator  136 . 
     A method for manufacturing the battery core  122  will now be discussed in further detail.  FIG. 4  is a flow chart illustrating a method  300  for creating the battery core  122 . The method  300  may begin with operation  304  and a solution cavity may be defined on the electrode collectors  132 ,  134 . 
     With reference to  FIGS. 5A and 5B , which illustrate various views of the electrode collector and a flow barrier  140 ,  142 , a flow barrier  140 ,  142  may form a perimeter wall or retaining structure that may extend around an edge of the collectors  132 ,  134  to define a solution cavity  146  or well between the inner surface of the flow barrier  140 ,  142  and the top surface of the collectors  132 ,  134 . For example, an anode flow barrier  142  and a cathode flow barrier  140  may be formed on respective electrode collectors  132 ,  134  to define the solution cavity  146  for each substrate or electrode collector  132 ,  134 . 
     In some embodiments the flow barriers  140 ,  142  may be integrally formed with the electrode collectors  132 ,  134 . For example, the flow barriers  140 ,  142  may be formed by folding or bending certain portions (e.g., the outer edges) of the electrode collectors  132 ,  134  upwards to define the solution cavity  146 . In other embodiments, the flow barriers  140 ,  142  may be a separate component from the electrode collectors  132 ,  134  and may be operably connected thereto or positioned thereon. For example, in some embodiments, the flow barriers  140 ,  142  may be a plastic wall formed through masking deposition process, may be formed while the electrode collectors are formed (e.g., metal injection molding the electrode collectors to define one or more recesses or walls), or may otherwise be defined or connected to the electrode collectors. 
     In some embodiments, the flow barriers  140 ,  142  may extend upwards from the electrode collectors  132 ,  134 . However, in other barriers, the solution cavity  146  may be defined as a well, e.g., through etching or otherwise forming recesses within the electrode collectors  140 ,  142 . In these embodiments, the flow barriers  140 ,  142  may be formed integrally with the electrode collectors  132 ,  134 . 
     It should be noted that although the flow barriers  140 ,  142  and the electrode collectors  132 ,  134  are illustrated as having a generally circular shape in  FIGS. 5A and 5B , the shape of the electrode collector  134  and the flow barrier  140  may be modified as desired. For example, the electrode collector and the flow barrier  140  may be rectangular, square, other geometric or non-geometric shapes, or the like 
     With reference again to  FIG. 4 , once the solution cavity  146  has been defined, the method  300  may proceed to operation  306 . In operation  306  the anode  128  and cathode  130  slurries or solutions  129 ,  131  may be created. As briefly discussed above, the anode and cathode solutions  129 ,  131  may each include an active material, a binder, and a conductive material. For the anode  128 , the active material may be lithium or graphite infused with lithium ions, the binder may be polyvinylidene fluoride, and the conductive additive may be carbon black. For the cathode  130 , the active material may be LiCoO 2 , the binder may be polyvinylidene fluoride, and the conductive additive may be carbon black. It should be noted that many other active materials, binders, and conductive additives are envisioned and the aforementioned compounds are illustrative only. Once the active material, binder, and conductive additives are combined to create the anode solution  129  and the cathode solution  131  slurries may be created. 
     The anode solution  129  and cathode solution  131  slurries may be a paste that may have a somewhat low viscosity, such that when placed on a surface the slurries may slide or roll over the edge of the surface. For example, when the solutions  129 ,  131  are initially created, the binder may not yet have hardened into a more solid structure and so the slurries may be very easily moved. 
     Once the solution  129 ,  131  slurries have been created, the method  300  may proceed to operation  308 . In operation  308  the solutions  129 ,  131  may be injected or deposited into their respective solution cavities  146 . That is, the anode solution  129  may be injected into the solution cavity  146  defined on the anode electrode collector  132  and the cathode solution  131  may be injected in to the solution cavity  146  defined on the cathode electrode collector  134 . The solutions  129 ,  131  may be injected through a variety of processes, such as, but not limited to, injection molding, deposition processes, or the like. 
       FIG. 6A  is a top plan view of the anode and cathode solutions  129 ,  131  received into the solution cavity  146 .  FIG. 6B  is a cross section view of the anode and cathode solutions  129 ,  131 , respectively, received into the solution cavity  146 . Referring to  FIGS. 6A and 6B , the cathode  131  solution (e.g., cathode active material, binder, and conductive particles) may be injected or poured into the solution cavity  146 . In some embodiments, the cathode solution  131  may be injected into the solution cavity  146  such as through injection molding, screen printing, masking, or other deposition techniques. Similarly, the anode solution  129  (e.g., anode active material, binder, and conductive particles) may be injected or poured into the respective solution cavity  146  defined on the anode electrode collector  132 . 
     The flow barriers  140 ,  142  may substantially prevent the liquid or pre-hardened solutions  129 ,  131  from rolling or flowing off of the edges of the electrode collectors  132 ,  134 . This is because the cathode solution  131  and/or anode solution  129  may have a somewhat low viscosity, but due to the flow barriers  140 ,  142  may be bound within the solution cavities. As described above with respect to operation  306 , the anode and cathode solutions  129 ,  131  may be a slurry, paste, or otherwise have a relatively low viscosity. 
     With the battery core  122 , the flow barriers  140 ,  142  may substantially contain the anode and cathode solutions  129 ,  131  within the well or solution cavity  146 . The flow barriers  140 ,  142  may therefore allow the amount of anode and cathode solutions  129 ,  131  applied to the electrode collectors  132 ,  134  to be increased. As will be discussed below, the increase in solution applied may increase the thickness of either or both the anode and cathode  128 ,  130  layers as compared to conventional batteries. This is because the flow barriers  140 ,  142  may prevent the slurries from sliding off of the collector. 
     With reference again to  FIG. 4 , once the anode and cathode solutions  129 ,  131  have been injected into or otherwise poured into the solution cavity  146 , the method  300  may proceed to optional operation  309 . In operation  309 , excess solution  129 ,  131  may be removed from the solution cavity  146 . In some embodiments, the anode and/or cathode solutions may be overfilled in the cavity  146 .  FIGS. 7A and 7B  illustrate the anode and cathode, respectively, being formed during operation  309 . With respect to  FIGS. 7A and 7B , a blade  160  or other tool (e.g., rod, level, or laser) may be used to remove excess slurry  162 ,  164  from each the anode solution  129  and the cathode solution  131 . For example, the excess slurry  162 ,  164  may be scraped off the top of the solution cavity  146  as the blade  160  extends across the top surface of the retaining barriers  140 ,  142 . 
     In some embodiments, operation  309  may be used to control the thickness and/or shape of the anode and/or cathode. In other words, the blade  160  may be configured to remove a predetermined amount of solution  129 ,  131  which may determine the overall thickness of the anode and cathode. 
     With reference again to  FIG. 4 , after the excess slurry  162 ,  164  has been removed or the anode solution  129  and cathode solutions  131  have been otherwise shaped as desired, the method  300  may proceed to operation  310 . In operation  310  the anode solution  129  and the cathode solution  131  may be cured or otherwise hardened. With respect to  FIGS. 8A and 8B , in some embodiments, the anode layer  150  (including the anode solution, the anode electrode collector, and the flow barrier) and the cathode layer  152  (including the cathode solution, the cathode electrode collector, and the flow barrier) may be heated to harden the anode and cathode solutions  129 ,  131 . For example, the anode  128  and cathode  130  (along with the respective electrode collectors) may be heated or baked to allow the binder to cure. However, the type of hardening process may depend on the type of solution used, and thus may vary as required. 
     In some embodiments, a nickel iron alloy such as INVAR or KOVAR may be utilized for operation  310 . Alternatively, other materials having a low or particularly selected (matched) coefficient of thermal expansion (CTE), in order to maintain particular dimensions with respect to the anode and cathode solutions  129 ,  131  during a heating and any subsequent cooling process used to cure or hardened the anode solution  129  and/or cathode solution  131 . 
     Returning again to  FIG. 4 , once the anode solution  129  and the cathode solution  131  have hardened, the method  300  may proceed to operation  312 . In operation  312  it may be determined whether the flow barriers  140 ,  142  should be removed. In some embodiments the flow barriers  140 ,  142  may be removed after the cathode or anode solution has hardened. This is because once hardened the cathode or anode solution may not roll off of the electrode collector. However, in other embodiment&#39;s the material of the flow barriers  140 ,  142  may be selected so as to not interfere with the chemical reactions within the battery core  122  and may remain in place during use. 
     In instances where the flow barriers  140 ,  142  may be plastic or other material portions operably connected to a top surface of the electrode collectors  132 ,  134  (such as an O-ring or donut shape), the flow barriers  140 ,  142  may be removed from the sides of the anode  128  and/or cathode  130 . For example, the flow barriers  140 ,  142  may be etched away, dissolved through a chemical reaction, or peeled or pulled away from the anode solution  129  and/or cathode solution  131 . However, in some instances, the flow barriers  140 ,  142  may be defined by edges of the electrode collectors  132 ,  134  and may not be removed or may be formed of an inert material and may not generally affect the performance of the battery core  122  and thus may not be removed. 
     If the flow barriers  140 ,  142  are removed, the method  300  may proceed to operation  314 . In operation  314 , encapsulation walls  158 ,  159  may be applied to the edges of the anode  128  and cathode  130 .  FIGS. 9A and 9B  illustrate the anode and cathode as the encapsulation walls  158 ,  159  are added. Operation  312  may include removing the flow barrier mask (e.g., flow barrier walls) and positioning a secondary or encapsulation mask with respect to the anode or cathode layers and the collector substrate. The encapsulant  158 ,  159  may be a thermoplastic or other polymer deposited about the anode and cathode solutions  129 , 131  based on the encapsulation mask geometry. 
     The encapsulant  158 ,  159  may form a structure barrier for the two solutions  129 ,  131 . The encapsulant  158 ,  159  may function as a structural retaining wall to help maintain the structure of the hardened solutions  129 ,  131  with the flow barriers  140 ,  142  removed. The encapsulant  158 ,  159  may also help to protect the anode and cathode. With reference to  FIGS. 9A and 9B , the encapsulation  158 ,  159  may be deposited onto the edges of the anode and cathode solutions  129 ,  131  after the flow barriers  140 ,  142  have been removed. Alternatively, holes may be defined in the flow barriers  140 ,  142  which may receive the material forming the encapsulation walls  158 ,  159 . Once the encapsulant  158  has been deposited it may need to be cured, in which case the method  300  may further including a curing time. The encapsulant  158 ,  159  may be cured by heating, ultraviolet radiation, or chemical means. Alternatively, a self-curing encapsulant compound may be utilized, for example an epoxy resin. 
     It should be noted that in some embodiments, the encapsulant  158 ,  159  may be provided whether the flow barriers  140 ,  142  are removed or not removed. Accordingly, operation  314  may be included within the process flow of the method  300  regardless of whether the flow barrier walls are removed. 
     With reference again to  FIG. 4 , if the flow barriers  140 ,  142  are not removed, or after operation  314 , the method  300  may proceed to operation  316 . With reference to  FIG. 10A , in operation  316 , an electrolyte  166  may be applied. During operation  314  the method  300  may also proceed to operation  318  and the separator  136  may be added. For example, the separator  136  material may be permeable and applied to either or both the anode  128  or cathode  130  layers and the separator  136  may be saturated or permeated with the electrolyte  166  material. Alternatively, operations  316 ,  318  may be separate, and the electrolyte  166  may be applied as a liquid first to either the anode or cathode, and then the separator  136  may be applied. It should be noted that in operation  318 , in some embodiments, additional encapsulant  158 ,  159  may be applied along with the separator  136  to the anode and/or cathode. 
     With reference to  FIG. 10B , in embodiments where the separator  136  may be a thin film, the separator  136  may be rolled onto either the anode layer  150  or the cathode layer  152 . However, in other embodiments the separator  136  may be positioned on top of, deposited, or otherwise connected to one of the layers  150 ,  152 . In some embodiments, the separators  136  may be applied to a top surface of the cathode layer  152  and may be cover a top surface of the encapsulate  158  and the cathode solution  130 . 
     Referring again to  FIG. 4 , once the separator  136  is in place, method  300  may proceed to operation  320 . In operation  320  the anode layer  150  and cathode layer  152  may be combined together.  FIG. 11  illustrates a schematic view of the battery core  122  with the two layers  150 ,  152  combined. With reference to  FIG. 11 , the cathode layer  150  may be positioned on top of the anode layer  152  with the separator  136  positioned between. Due to the flow barrier walls  140 ,  142 , the anode  128  and the cathode  130  may have an increased thickness as compared to conventional lithium ion batteries. For example, the cathode  130  may have a thickness ranging between 10 to 25 microns. This increased thickness may provide for an increased energy density as more electrons may be stored in the anode and cathode as compared to thinner anode and cathode layers. 
     Additionally, because the anode  128  and cathode  130  layers may be constructed thicker, the battery core  122  may not need to be wound around itself to provide sufficient energy density for providing power to the electronic device  100 . This may allow for the thickness of the anode electrode collector  132  and/or the cathode electrode collector  134  to increase in thickness. By increasing the thickness the collectors  132 ,  134  may be formed molded to conform to certain shapes and may help to form the flow barriers for the solutions, this will be discussed in more detail below with respect to  FIG. 13 . 
     Returning again to  FIG. 4 , after the anode  128  and cathode  130  have been sandwiched together, the method  300  may proceed to the end state  322  and may terminate. 
     In some embodiments, the cathode layer  152  as formed in  FIG. 9B  may be operably connected with a metal anode deposition rather than the anode solution illustrated in  FIGS. 9A-11 . With reference to  FIGS. 12A-12C , after the cathode layer  152  has been formed as illustrated in  FIG. 9B , an electrolyte layer such as lithium phosphorous oxynitride (LiPO x N y ) may be applied to a top surface of the cathode  130  and encapsulant  158 ,  159 . For example, once the electrolyte layer is deposited, a lithium (Li) metal layer  172  may be deposited on top of the electrolyte layer  170 .  FIG. 12B  illustrates the Li metal layer  172  being formed on top of the electrolyte layer  170 . The Li metal layer  172  may be applied as a powder deposition or a physical vapor deposition (PVD). With reference to  FIG. 12C  once the Li metal layer  172  is formed, the anode electrode collector  132  may be operably connected on top of the Li metal layer  172  with a flexible sealant  172  connecting the anode electrode collector  132  to the encapsulate  158 . 
     As briefly highlighted above, because the battery core  122  may be stacked rather than rolled, due to the increased thickness of the anode and cathode layers, the electrode collectors  132 ,  134  or substrates may be increased in thickness. Conventional lithium ion batteries typically include electrode collectors that are a thin, flexible material (e.g., aluminum foil) so that the collectors can be wrapped around themselves when the jelly roll (e.g., rolled package of the substrate, anode, and cathode) is formed. The flexibility required for the jelly roll configuration may limit the thickness and/or materials that may be used for the battery core. However, with the battery core  122  manufactured with the method  300 , the increased anode  128  and cathode  130  thickness may allow for the core  122  to be stacked rather than rolled. The stacking may allow the electrode collectors  132 ,  134  to be thicker and/or formed of non-flexible materials, which may allow the collectors to be molded or otherwise formed as desired.  FIG. 13  is simplified cross-section view of an electrode collector  234  including a surface corresponding feature. In some embodiments, either or both of the electrode collectors  132 ,  134  may be molded or otherwise formed to define a particular shape. For example, the electrode collectors  132 ,  134  may be molded to generally correspond to the bottom surface  118  of the enclosure. For example, the electrode collector  234  may be metal injection molded (MIM), machined, or otherwise formed to correspond to a desired shape. 
     In these embodiments, the electrode collectors  132 ,  134  may have an increased energy density efficiency, as the solution cavity  146  for holding the anode or cathode solutions may trace along the topography of the enclosure which may provide for the maximum amount of internal space for the solutions. 
     With reference to  FIG. 13 , the electrode collector  234  may include a surface corresponding feature  248  which may be a raised protrusion defining a protraction slot  250 . In this embodiment, the protrusion slot  250  may be configured to receive a protrusion, such as a ridge or discontinuity on the bottom surface  118  (or other surface) of the enclosure  102 . Rather than reducing the entire height of the electrode collector  234  and thus the amount of solution it can contain, the electrode collector  234  may include the surface corresponding feature  248  that may be raised into the solution cavity. Accordingly, although the height of the solution cavity may be reduced at the surface corresponding feature  248  (to accommodate the protrusion), the entire volume of the solution cavity may not have to substantially reduced to accommodate the protrusion. 
     The electrode collector  234  may be used to form either the anode electrode collector and/or the cathode electrode collector. Additionally, the electrode collector  234  may be shaped to corresponding to a number of different surfaces, dimensions, and/or shapes. For example, the electrode collector  234  may be configured to match an internal surface of the battery housing  114  versus the enclosure. Moreover, although the electrode collector  234  has been discussed as being injection molded, other forming techniques may be used. 
     The foregoing description has broad application. For example, while examples disclosed herein may focus on batteries for electronic devices, it should be appreciated that the concepts disclosed herein may equally apply to substantially any other type device using a portable or rechargeable power supply. Similarly, although the methods are discussed with respect to certain manufacturing techniques, the battery structures may be manufactured in other methods or techniques. Accordingly, the discussion of any embodiment is meant only to be exemplary and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples.

Metadata:
Filing Date: 20130930
Publication Date: 20180724
Grant Date: 20180724
Priority Date: 20121127
Inventors: ANASTAS, GEORGE V.
SPRINGER, GREGORY A.
RECTOR, III, JACK B.
FUNAMURA, Joshua R.
SILZ, Kenneth M.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01M10/058", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/0409", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/058", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/76", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/0404", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M4/0409", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/76", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/0404", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/76", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M4/0404", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M4/0409", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/058", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02P70/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02E60/10", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 50773576