PATENT DOCUMENT

Publication Number: US-8518569-B2
Application Number: US-71473710-A
Country: US
Kind Code: B2

Title: Integrated frame battery cell

Abstract:
An electrolyte containment structure for an electrode jelly roll and electrolyte in a portable power source is described. The electrolyte containment structure comprises metal foil, such as metal foil sleeve, coupled to and partially surrounding a rigid frame. The rigid frame can protect the electrode jelly roll edges from crush events. To prevent shorts, the metal foil can be coated in plastic, which can insulate the metal foil from the electrode jelly roll. Further, the plastic can serve as a bonding and sealing agent. For instance, the metal foil can be coupled to the rigid frame using a thermal bonding method involving melting of the plastic. The rigid frame can provide a platform for connector pads and safety circuitry associated with the portable power source. The connector pads and safety circuitry can be assembled as modular components, which can simplify the assembly process The containment structure provides features associated with a pouch cell battery design, such as a light-weight metal foil pouch, but can be utilized in a portable computing device without being enclosed in a hard casing traditionally associated with pouch cell battery designs.

Claims:
What is claimed is: 
     
       1. A portable computing device comprising:
 a display; 
 a processor; 
 a memory; 
 two or more portable power sources for providing power to the display, the processor and the memory, wherein each of the two or more portable power sources comprises:
 an electrode assembly including an anode and a cathode; 
 an electrolyte; 
 power conditioning circuitry for changing a voltage output level of the portable power source; 
 a containment structure for enclosing the electrode and the electrolyte, the containment structure configured to prevent leakage of the electrolyte or gasses generated during operation of the portable power source; the containment structure comprising:
 a rigid frame; 
 a metal foil bonded to the rigid frame wherein the metal foil encloses a portion of the rigid frame, the electrode assembly and the electrolyte; and 
 a vent configured to evacuate the containment structure which places the containment structure in a low pressure condition under vacuum; 
 
 an electrical connector pad coupled to the rigid frame for drawing power from the portable power source; and 
 safety circuitry coupled to the rigid frame; the safety circuitry electrically coupled to the electrical connector pad and the anode and the cathode of the electrode assembly; and 
 
 power control circuitry separate from the two or more portable power sources, wherein the power control circuitry is configured to command each of the two or more portable power sources to change their voltage output level using the power conditioning circuitry. 
 
     
     
       2. The portable computing device of  claim 1 , wherein the power control circuitry is further configured to allow the two or more portable power sources to be operated in parallel mode, in a series mode or an independent mode. 
     
     
       3. The portable computing device of  claim 2 , wherein the power control circuitry is further configured to switch the two or more portable power sources between the parallel, series and the independent operational modes. 
     
     
       4. The portable computing device of  claim 1 , wherein the electrode assembly and the electrolyte form a lithium ion polymer battery cell. 
     
     
       5. A portable power source, the portable power source comprising:
 an electrode assembly including an anode and a cathode; 
 an electrolyte; 
 a containment structure for enclosing the electrode and the electrolyte, the containment structure configured to prevent leakage of the electrolyte or gasses generated during operation of the portable power source; the containment structure comprising:
 a rigid rectangular-shaped frame, 
 a metal foil bonded to the rigid rectangular-shaped frame,
 wherein the metal foil encloses a portion of the rigid rectangular-shaped frame, the electrode assembly and the electrolyte, 
 wherein a portion of the bond between the rigid rectangular-shaped frame and the metal foil prevents the electrolyte or the gasses from escaping the containment structure, and 
 
 a vent configured to evacuate the containment structure which places the containment structure in a low pressure condition under vacuum; 
 
 an electrical connector pad coupled to the rigid rectangular-shaped frame for drawing power from the portable power source; and 
 safety circuitry coupled to the rigid frame; the safety circuitry electrically coupled to the electrical connector pad and the anode and the cathode of the electrode assembly. 
 
     
     
       6. The portable computing device of  claim 1 , wherein the portable computing device is selected from the group consisting of a laptop computer, a netbook computer, a tablet computer, a smart phone and a portable media player. 
     
     
       7. The portable computing device of  claim 1 , wherein the rigid frame includes an injection port and the electrolyte is added to the containment structure via the injection port. 
     
     
       8. The portable computing device of  claim 1 , wherein the metal foil is provided as a metal pouch or as a metal sleeve. 
     
     
       9. The portable computing device of  claim 1 , wherein the metal foil is heat sealed to the rigid frame. 
     
     
       10. The portable computing device of  claim 1 , wherein the metal foil includes a laminate layer between the metal foil to the rigid frame. 
     
     
       11. The portable computing device of  claim 1 , wherein the electrode assembly comprises a jelly roll electrode assembly. 
     
     
       12. The portable computing device of  claim 1 , wherein the metal foil is aluminum. 
     
     
       13. The portable computing device of  claim 1 , wherein the metal foil is between 80 to 150 microns thick. 
     
     
       14. The portable computing device of  claim 1 , wherein the rigid frame includes a corner and wherein the metal foil is bonded to the rigid frame around the corner. 
     
     
       15. The portable computing device of  claim 14 , wherein the bond around the corner of the rigid frame prevents the electrolyte or the gasses from escaping the containment structure. 
     
     
       16. The portable computing device of  claim 1 , further comprising electrical connector pads, wherein the safety circuitry and the electrical connector pads are integrated into the rigid frame. 
     
     
       17. The portable computing device of  claim 1 , further comprising electrical connector pads, wherein the safety circuitry and the electrical connector pads are integrated into a board that is bonded to the rigid frame during assembly.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The described embodiments relate generally to batteries for portable computing devices. More particularly, the present embodiments relate to battery packaging designs for portable computing devices. 
     2. Description of the Related Art 
     A design of a portable computing device can involve complex tradeoffs. A few factors that can be considered in the design process are cosmetic appeal, weight, manufacturability, durability, thermal compatibility and power consumption. A component that is selected on the basis of its positive contribution to one of these design factors can have an adverse impact on one of more other design factors. 
     A portable power source, typically, a battery of some type is an important component in the design of a portable computing device. The portable power source provides operating power for the portable computing device when it is not near a fixed power source, such as a wall outlet. Factors in selecting a portable power source can be energy density, form factor and durability. 
     Energy density can refer to the amount of energy per given volume or per given mass that the portable power source is capable of delivering to the portable computing device. The form factor can refer to the shape of the package containing the portable power source. For instance, portable computing devices that are slim require an overall form factor for the portable power source that is also slim. The durability can relate to containment of any damaging elements associated with a battery cell. For example, portable power sources often include liquid or gel type electrolytes that need to be contained to prevent damage to other electronic components where the packaging needs to be durable enough to contain these damaging elements under normal operational conditions. 
     The energy density for a portable power device, such as a battery, can be affected by the type battery cell that is employed and its associated packaging. The packaging design can affect the energy density in a number of ways. First, the energy density per mass will decrease as the mass of the packaging increases. The packaging decreases the energy density per mass because it adds mass to the system without providing additional energy. The mass of the packaging design can be constrained by durability considerations. 
     Second, the energy density per volume is affected by packing efficiency where the packing efficiency can be constrained by a desired form factor for the packaging design. An inefficiently packaged battery cell can have a lower energy density per volume than an efficiently packaged battery cell. As the energy density per volume decreases, the volume taken up by the portable power device increases, which can be undesirable for utilization with a portable computing device. 
     In a portable computing device, it is generally desirable to minimize the weight and volume of each component while still maintaining desired functionality and performance levels. Therefore, it would be beneficial to provide a housing assembly for a battery useable in at least a portable computing device that is durable, lightweight and efficiently packaged. It would also be beneficial to provide methods for assembling the battery that meet the above conditions and perform satisfactorily during operational cycling of the device. 
     SUMMARY OF THE DESCRIBED EMBODIMENTS 
     This paper describes various embodiments that relate to systems, methods, and apparatus for enclosures for use in portable computing applications. 
     In one aspect, a portable power source and its method of manufacture is described. The portable power source can be used in portable power devices such as but not limited to lap top computers, netbook computers, smart phones and portable media players. The portable power source can include a containment structure for enclosing an electrode and an associated electrolyte in a battery cell, such as a lithium-ion polymer battery cell. The containment structure can prevent leakage of the electrolyte or gasses generated during operation of the portable power source. 
     The containment structure can include a rigid frame and a metal foil bonded to the rigid frame where the metal foil encloses a portion of the rigid frame, the electrode assembly and the electrolyte. The rigid frame can protect an electrode, such as edges of the electrode jelly roll, from crush events, which can damage the electrode. To prevent shorts, the metal foil can be coated in plastic, which can insulate the metal foil from the electrode of the battery cell. Further, the plastic can serve as a bonding and sealing agent. For instance, the plastic, via a thermal bonding method, can be melted to bond the metal foil to the rigid frame and to form an air-tight seal for containing a liquid or gel electrolyte associated with the battery cell. 
     An electrical connector pad and safety circuitry can be coupled to the rigid frame. The electrical connector pad can allow power to drawn from or added to the portable power source. The safety circuitry can be electrically coupled to the electrical connector pad and the anode and the cathode of the electrode assembly. In particular embodiments, the safety circuitry and the electrical connector pad can be an integral component of the rigid frame or can be provided as a modular component that is coupled to the rigid frame during assembly. Providing the safety circuitry and electrical connector pads in this manner can simplify the assembly process. 
     In another embodiment, the rigid frame can include an injector port that allows the electrolyte to be added to the containment structure during assembly of the portable power source. The injector port can be aligned with an axis around which an electrode jelly roll is wound to allow the electrolyte to be injected in an axial direction. Injecting the electrolyte in this manner can allow for a faster assimilation of the electrolyte into the electrode jelly roll as compared to when the electrolyte is injected in a transverse direction. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  shows a perspective view of components of a portable power source prior to assembly. 
         FIG. 2  shows a perspective view of a portable power source after assembly. 
         FIG. 3  is a front view of an unassembled containment structure for enclosing an electrode and associated electrolyte for one embodiment. 
         FIGS. 4A and 4B  are a front view of an unassembled containment structure for enclosing an electrode and associated electrolyte for various embodiments. 
         FIG. 5  is a block diagram of a power source distribution scheme for a portable computing device. 
         FIG. 6  is a flow chart of a method of generating a portable power source. 
     
    
    
     DETAILED DESCRIPTION OF SELECTED EMBODIMENTS 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     The following relates to housing assemblies for portable power source, such as a battery. The portable power source can be suitable for a portable computing device such as but not limited to a laptop computer, netbook computer, tablet computer, smart phone, a portable media player, etc. In particular, the housing assembly comprises a rigid frame integrated into the pouch of a pouch type battery cell. A portion of the rigid frame can provide containment for a liquid electrolyte associated with the battery. The rigid frame can include an electrical interface, safety circuitry and voltage conditioning circuitry. 
     A general description of a ‘pouch cell’ type battery including a rigid frame is described with respect to  FIG. 1 . In  FIG. 1 , pre-assembled components including a metal pouch, electrode jelly roll and a frame are shown. In  FIG. 2 , the components after assembly are shown. Alternate embodiments of forming a pouch cell with an integrated frame are described with respect to  FIGS. 3 ,  4 A and  4 B. In  FIG. 5 , a portable computing device including multiple power sources distributed in a device casing are shown. A method of assembling a pouch cell battery with a rigid frame is described with respect to  FIG. 6 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. 
       FIG. 1  shows a perspective view of components of a portable power source  100  prior to assembly. A perspective view after assembly is shown in  FIG. 2 . The portable power source can comprise a metal pouch  104  or metal sleeve, an electrode jelly roll assembly  102  (often denoted as a ‘bare cell’) and a frame  124  and a board  114  including connection circuitry. The electrode jelly roll  102  can comprise a sheet with a number of layers, such as a layer of cathode material, a layer of anode material and a separator material between the anode and cathode layer. The sheet can be rolled or folded up to from the electrode jelly roll. In one embodiment, the cathode material can include lithium. The lithium anode material along with a suitable cathode material, such as porous carbon, can be used to form a lithium ion type battery. 
     In a particular embodiment, a liquid or gel electrolyte can be used with the electrode jelly roll  102 . A lithium ion battery is an example of a battery system using a liquid or gel electrolyte. In another embodiment, a dry electrolyte, such as a polymer electrolyte can be used with the electrode jelly roll  102 . A dry lithium polymer battery is one example of battery system employing a dry electrolyte. In particular embodiments, a gel or liquid electrolyte can be used in combination with a dry electrolyte, such as the polymer electrolyte. For instance, a lithium ion polymer battery uses a polymer electrolyte in combination with a liquid or gel electrolyte. The liquid or gel electrolyte can be added to improve the conductivity of the battery system at lower temperatures, such as at room temperature conditions or colder. 
     The electrode jelly rode  102  can comprise electrode tabs  108 . The electrode tabs can include a positive and a negative tab. The electrode tabs can be covered by an insulator, such as  106 . The insulator  106  can be used to prevent shorts from occurring across the two electrode tabs. For instance, a short could occur if the metal pouch  104  came into contact with bare portions of each electrode tab  108 . 
     The metal pouch  104  can be formed from a metal foil, such as an aluminum foil. The metal foil can be coated with a laminate layer, such as a plastic laminate layer. The laminate layer can be used for heat sealing purposes. For example, in one embodiment, a metal pouch  104  can be formed by starting with a rectangular metal foil sheet coated with a laminate layer. The opposite ends of the rectangular metal foil sheet can be overlapped and pressed together. Then, heat can be applied along the overlapped edge to melt the laminate layer and join the two overlapped edges together to form a metal sleeve. 
     Further, the plastic laminate layer can insulate the metal foil from the electrode jelly roll  102 . A contact of the metal in the metal foil pouch  104  with the electrode jelly roll  102  can result in electrical shorts. The plastic laminate layer, acting as an insulator, can prevent the metal in the metal foil pouch  104  from contacting the electrode jelly  102  roll and causing a short circuit to occur. 
     In another example, two sheets of a metal foil coated with a laminate can be utilized. One sheet of metal foil can be stacked on top another sheet of metal foil. Then, opposite sides of the two sheets can be pressed together and heat sealed proximate to the edges to again form a metal sleeve. 
     The sheets can be joined such that the laminate layer is located on an inner surface of the metal sleeve. The inner surface can face and can be in contact with the electrode jelly roll  102  after assembly. The laminate layer can be a plastic polymer, such as but not limited to polypropylene or polyethylene. 
     Next, one edge of the metal sleeve can be pressed together and then heat can be applied along the pressed together edge to seal one end of the metal sleeve to form a pouch, such as metal pouch  104 . In particular embodiments, the metal foil layer can be about 80-120 microns thick. In other embodiments, the metal foil layer can be as thick as 140 microns. The thickness of the foil layer can be increased to increase durability and damage resistance. 
     In yet other embodiments, other bonding agents, such as a liquid adhesive can be applied to bond various components together, such as to seal an end of a metal sleeve to form a pouch. In this embodiment, heat sealing may not be used or can be used in conjunction with the liquid adhesive. A seal can be formed when the liquid adhesive dries. In other embodiments, a combination of heat sealing and/or other bonding schemes, such as the use of a tape or a liquid adhesive can be used to bond one or more components together including but not limited to forming a seal. 
     The electrode tabs  108  of the electrode jelly roll  102  can be welded to electrical contacts on board  114 . The board  114  can provide a substrate for various electrical components, such as the safety circuitry  112  and electrical connector pads  110 . The board can be constructed from a material, such as a plastic, and other suitable materials useful with printed circuit boards (PCBs). 
     The board  114  can be provided as a modular component or can be an integrated component of the rigid frame  124 , described below. When the board  114  is provided as an integral or modular component to the rigid frame, the assembly process can be simplified because the rigid frame can provide a more stable platform for the assembly process than assembling this circuitry separately from the rigid frame  124 . Further, securing the board  114  to the rigid frame  124  can prevent disconnects that can occur when the circuitry is merely “hanging” from the electrode jelly roll  102 , such as disconnects resulting from the circuitry snagging on something during manufacture. 
     The electrical contacts can connect the electrode jelly roll to safety circuitry  112 . The safety circuitry  112  can be configured to cut off current from the electrode jelly roll  102  in response to a condition of the electrode jelly roll  102  at the electrode tabs  108 . As an example, the safety circuit can be configured to shut down the battery when it is charged above a certain voltage level and discharged below a certain voltage level. In a particular embodiment, the safety circuitry  112  can include an element, such as a thermal interrupt that opens a circuit in response to an over current and/or overcharging conditions. 
     In particular embodiments, the safety circuitry  112  can include one or more sensors for detecting conditions of the electrode jelly roll, such as current and voltage levels. This information can be used to determine a charge remaining in the electrode jelly roll  102 . In addition, other safety features that can be associated with the portable power source include but are not limited circuitry or a device that responds 1) to over-temperature conditions, such as a shut down separator and 2) internal pressure conditions, such as a tear-away tab or a vent. 
     The safety circuitry  112  can be interposed between the electrode tabs  108  and the connector pads  110 . The connector pads  110  provide an external interface that allows power to be drawn the portable power device after assembly. The board  114  can also include power conditioning circuitry (not shown). In one embodiment, the power conditioning circuitry can allow the voltage output from portable power device to be altered. For instance, the voltage output by the electrode jelly roll  102  (after assembly) can vary according to its charge state. The power conditioning circuitry can increase or decrease voltages to match voltage requirements needed by an electronic component receiving power from the portable power source. In some embodiments, as discussed with respect to  FIG. 5 , a portable computing can comprise multiple power sources and the power conditioning circuitry can be configured to adjust output voltages based upon the charge states of one or more of the power sources. 
     The portable power source can include a frame  124 . The frame can be constructed from a plastic material, such a polypropylene. The frame material can be selected such that it can form a heat-sealed bond with the plastic laminate of the metal pouch  104 . The frame  124  can be more rigid than the metal foil pouch  104  such that it provides structural rigidity to the assembled portable power source  100  (see  FIG. 2 ). The additional rigidity can prevent damage to the electrode jelly roll  102  that could result from the roll being bent or twisted. 
     Further, the edges of the electrode jelly roll  102  can be susceptible to damage resulting from the edges of the electrode jelly  102  being crushed. For instance, crush events can occur while the portable power source is being assembled. The rigid frame can protect the edges of the electrode jelly roll from being crushed. 
     For the purposes of discussion, the frame  124  can be described as having sides,  119   b  and  119   b , a front  119   c  and a back  119   d , top  121   a  and a bottom  121   b . In  FIG. 1 , the frame is shown bottom side up. In a particular embodiment, the frame  124  can be rectangular with a transverse member  124 . The frame can be sized so that it surrounds the electrode jelly roll  102 , i.e., the electrode jelly roll fits within the space  125  provided by three sides of the frame  124  and the transverse member  122 . The board  114  can be sized such that it fits between the transverse member  122  and front member  123 . Members  122  and  123  can be connected by a solid surface on the top side  121   a  to form a cavity. The top side solid surface can include an aperture  118 . The aperture is configured to allow access to the connector pads  110  on board  114 . 
     In one embodiment, the board  114  can be provided as an integral component of frame  124 . The connector pads  110  and safety circuitry  112  can be built into the frame  124  during manufacture of the frame  124 . Thus, in some instances, the board  114  may not be assembled as a separate piece from frame  124 . 
     The frame  124  can comprise additional structure, such as the structure the around two mounting holes  116   a  and  116   b . A screw or some other type of fastener can inserted through the mount holes  116   a  or  116   b  to allow the portable power source to be coupled to another structure, such as a frame or a casing associated with a portable computing device. In other embodiments, one or more mounting holes can be placed at various locations around frame  124  and is not limited to two mounting holes in the locations shown in  FIG. 1 . In yet other embodiments, the frame may not include mounting holes but may include a ledge or other structure that can be used with a fastener to secure the portable power source to another structure. 
     To assemble the portable power source, the electrode tabs  108  can electrically coupled to contacts on the board  114 . Then, the electrode jelly roll assembly  102  and board  114  can be placed within the frame  124  such that the board  114  fits within the space between the members  122  and  123  with the connector pad  110  surrounded by aperture  118 . The connector pads  110  are accessible through the top  121   a  of the frame. The electrode assembly  102  and the board  114  are shown being flipped over prior to being placed in the frame  124 . As the board  114  and electrode assembly  102  can be assembled in the opposite orientation, this motion is not necessary and is shown for illustrative purposes only. 
     In some embodiments, the frame  124  can include a ledge on which the electrode jelly roll  102  can rest. The ledge could extend all around the sides of space  125 , could just be located proximate to the corners. Also, the ledge could span only a portion of each side, such as small tabs that extend into space  125  located at the midpoint of each side. Again, these tabs can support the electrode jelly roll  102  when it is placed in the frame  124 . 
     The board  114  and/or a portion of the electrode tabs  108  can be bonded to the frame  124 . For example, a liquid adhesive, such as an epoxy resin, can be used to bond the board  114  to frame  124 . It may be desirable to bond the electrode tabs  108  and/or the insulator surrounding the electrode tables to the frame to prevent leakage of electrolyte and/or venting of gasses between the electrode tabs and the frame  124 . 
     In embodiments, where the connector pads and safety circuit  112  are integral components of frame  124 , the frame  124  can comprise two contact points for coupling the electrode tabs  108  to the frame and the associated circuitry located within the frame. For example, electrical contact points can be located on a side of the member  122  facing the electrode jelly roll  102  when it is surrounded by the frame, i.e., side facing towards back  119   a . The electrode tabs  108  can include an end portion bent proximately 90 degrees to the orientation shown in  FIG. 1 . The end portion can be welded to the contacts on the surface of member  122 . 
     In another embodiment, the member  122  can comprise two slots on the side facing the electrode jelly roll  102  through which the electrode tabs  108  can be inserted. The electrode tabs  108  can be welded into to these slots. In yet other embodiments, the contact points for the electrode tabs  108  can be located in other locations, such as in the trough areas between members  122  and  123 . 
     In another example, a small surface is shown around each of the mounting holes  116   a  and  116   b , which are surrounded by the trough area. Rather than small surfaces surrounded by the trough area, the surface can extend between members  122  and  123  such that the trough area is eliminated and the surface is parallel with the bottom  121   b . The electrical contact points for the electrode tabs  108  can be located on this surface. 
     After the electrode jelly roll  102  is coupled to the frame  124 , the metal pouch  104  can be slid over the frame  124  and electrode jelly roll  102 . The metal pouch  104  can be bonded to the frame  124  to form a containment structure for a liquid or gel electrolyte associated with electrode jelly roll  102 . The bond between the frame  124  and the metal pouch  104  can act as a barrier to prevent leakage of an electrolyte and gasses associated with the electrode, such as the electrode jelly roll. 
     In one embodiment, an inner surface of the metal pouch  104  proximate to the open end can be bonded to the frame  124  proximate to the transverse member  122 , i.e. on an outside portion of side  119   b  proximate to the intersection of side  119   b  and transverse member  122 . Again, the bond can be formed using a heat sealing approach. As previously described, the inner surface of the metal pouch  104  can include a plastic laminate layer that is compatible with the material of frame  124  such that a leak-proof bond can be formed between the metal foil and the frame  124 . 
     The thermal bond can be generated by applying heat using a heating element of some type to the metal foil of the metal pouch  104 . The heat from the heating element can be conducted through the metal foil and melt and underlying laminate layer to bond the metal foil to the frame  124 . The thermal bond can extend along a top and a bottom edge of member  122  and along the sides of frame  124  in a line connecting the top and bottom edges, i.e., around the corners. The thickness of member  122  can be selected such that there is a large enough surface area along the edge of member  122  to form an adequate leak proof bond between the frame  124  and the metal pouch  104 . 
     In general, bonds, such as thermal bonds, can be generated between the frame  124  and the metal pouch  104  that conform to the geometry of the frame and are not limited to forming bonds around only frames with corners. For example, a bond can be formed between the metal pouch and the frame when the frame includes a more rounded surface, such as a rounded corner. In another example, the frame  124  could include a step and the metal pouch  104  could be bonded to the frame to form a leak proof seal across the step. 
     The metal pouch  104  can be thermally bonded to the frame  124  in other locations, such as along sides  119   a  and  119   d  of frame  124 , on an outside portion of back side  119   a , along the top  121   a  and bottom  121   b  edges of portions of each side, etc., to prevent slippage between the frame  124  and the metal pouch  104 . In this instance, the bond may not be necessary to prevent leakage from the containment structure formed by the metal pouch  104  and the frame  124 . Thus, in some bond areas, the metal pouch  104  can be bonded to the frame  124  to prevent leakage and in other areas, the metal pouch can be bonded to the frame  124  to allow the frame to add rigidity and provide support to the metal pouch  104 . 
     After bonding the metal pouch  104  to the frame  124 , a liquid or gel electrolyte can be added. In one embodiment, the member  122  can include an injection port  120  for adding the electrolyte. The injection port  120  can be a piece of rubber pre-bonded to member  122 . A needle containing the electrolyte can be inserted through the rubber piece of the injection port and then the electrolyte can be injected into the containment structure comprising the metal pouch  104  and frame  124 . When the needle is removed the rubber contracts to seal in the electrolyte. In this embodiment, the electrolyte can be injected in the direction of the axis around which the electrode jelly roll  102  is wound. 
     Injecting the electrolyte in the direction of the axis around which the electrode jelly roll is wound can allow for faster assimilation of the electrolyte into the jelly roll as compared to when the electrolyte is injected transversely to the axis. The faster assimilation of the electrolyte can decrease a manufacture time associated with assembling the portable power source. A decreased manufacture time can increase a production throughput and reduce manufacturing costs. 
     After a time period sufficient time period to allow the electrolyte to diffuse into the electrode jelly roll  102 , excess gasses can be evacuated from containment structure. For instance, in one embodiment, the portable power source can be placed in a vacuum and a hollow needle can be placed in the injection port  120  to allow gasses to escape from the containment structure to the vacuum via the hollow needle. Next, the needle can be removed and the injection port can be further sealed if desired. For instance, an epoxy resin or some other sealant can be placed over the injection port. 
     In other embodiments, after the electrolyte is added to the containment structure surrounding the electrode jelly roll  102 , excess gasses can be evacuated by making a cut in the metal pouch, such as at a corner or along the back edge (non-open end of the metal pouch  104 ). Example cut lines  117  are shown in the figure. The closed end of the metal pouch can extend past a back side  119   a  of the frame  124  to facilitate a cut. After a cut is made, the metal pouch can be heat sealed at the location of the cut to reseal the pouch. For instance, the cut edges can be pressed together and heat sealed Excess material can be folded and possibly bonded (e.g., taped) to the back side  119   a  of frame  124  if desired. 
     In some embodiments, cutting can be used in lieu of the injection port  120 . For instance, after the metal pouch  104  is coupled to the frame  124 , a hole can be cut in the metal pouch  104 , the electrolyte can be injected through the hole and then the pouch resealed. In another embodiment, the metal pouch  104  can be formed as a sleeve that is slipped over the frame  124 . One end of the sleeve can be bonded to the frame  124  (other portions of the sleeve can also be bonded to the frame at this time), then the electrolyte can be added through the other, open end of the metal sleeve proximate to the back side  119   a  of frame  124 . Next, the open end of the metal sleeve can be sealed and the electrolyte allowed to diffuse as previously described. In yet other embodiments, rather than using a metal pouch, the electrode jelly roll  102 , board  114  and frame  124  can be placed on a metal sheet, such as an aluminum foil sheet. In manners previously described, the edges of the metal sheet can be folded, bonded to itself and bonded to the frame  124  to form a containment structure for the electrolyte. 
     In a particular embodiment, the metal pouch  104  can placed around the frame  124 , board  114  and electrode jelly roll  102  such that these elements are initially entirely enclosed. The metal pouch  104  can be bonded to the frame  124  at various locations, such as but not limited to along the back  119   a , along the sides  119   b  and  119   d , along the front side  119   c , along edge  122  and/or around the aperture  118  on the top surface surrounding the aperture. The connector pads  110  can be initially covered by the metal pouch  104  and then a portion of the metal pouch  104  covering the connector pads  110  can be removed to expose the connector pads. Also, a portion of the metal pouch  104  can be removed or the metal pouch can be punctured to expose mounting holes  116   a  and  116   b  if desired. As previously described, the metal pouch can be cut and then resealed to add electrolyte and to evacuate gasses from the containment structure formed by the combination of the metal pouch  104  and the frame  124 . 
       FIG. 2  shows a perspective view of a portable power source  100  after assembly of the components described with respect to  FIG. 1  for one embodiment. The portable power source  100  is of a length  134 , width  130  and height  132 . These dimensions can be varied. For instance, the height  132  of the battery can be between 3-6 mm although smaller and larger thicknesses are possible. The thickness of the electrode jelly roll can be varied depending on the thickness  132  of the portable power source  100 . Thus, more or less windings can be associated with the jelly roll electrode enclosed by the metal pouch  104  and frame  124  depending on the selected thickness of the portable power source  100 . The thickness  132 , as well as the length  134  and width  130  of portable power source  100  can be selected to meet space requirements of a portable computing device for which the portable power source is utilized. 
     In one embodiment, connector pads with common dimensions  110  can be used that do not change when the dimensions of the battery change. For instance, the same sized connector pads can be used with a battery that is 3 mm thick or a battery that is 6 mm thick or when the length  130  and the width  134  of the portable power source are changed. The frame  124  can include small depressions or bumps proximate to the connector pads  110 . These bumps or depressions can be used to align the connector pads with other electrical interfaces. Alignment pins  126  (bumps) are shown in the figure. 
     The connector pads  110  are not limited to the location on surface  127  shown in  FIG. 2 . For example, the connector pads  110  can be located at other locations along surface  127 . As another example, the connector pads  110  can be located on a front surface of member  123 . Frames can be constructed that allow for the connector pad to be located on any portion of an outer portion of the battery  100 . 
     In particular embodiments, the battery  100  can comprise multiple connector pads, such as two or more connector pads. Multiple connector pads can allow multiple batteries to be coupled together. For example, two batteries can be coupled together side to side or two batteries can be stacked on top of another. The two batteries that are coupled together do not necessarily need to have the same dimensions. Allowing batteries of different dimensions to be coupled together may allow for a better utilization of available space within a portable computing device. 
       FIG. 3  is a front view of an unassembled containment structure for enclosing an electrode and associated electrolyte. The electrode and electrolyte can be an electrode jelly roll as described with respect to  FIGS. 1 and 2 . The shape of the electrode can be proximately rectangular. The containment structure includes a frame  155  and a metal pouch. The rigid frame  155  can comprise a transverse member  156 , a trough  160  with an aperture  118 . The aperture can be used for electrical connector pads as described with respect to  FIGS. 1 and 2 . 
     As compared to the frame  124  in  FIGS. 1 and 2 , frame  155  comprises a number of flanges  150  and a wider transverse member  156 . The flange  150  can be thinner than the maximum thickness of the frame  155 . For example, the maximum thickness of the frame  155  can be proximately the height of the electrode jelly roll assembly, such as 3-6 mm thick, while the thickness of the flange is thinner, such as 1 mm thick. The transverse member can have the same thickness as the flange. The flange width can vary and does not have to be a constant width on all sides of the frame. 
     The flange  150  can provide an increased bonding area to which the metal foil pouch  104  can be coupled to the frame  155 . As previously described, the metal foil pouch can be  104  thermally bonded to the frame  155  to form a containment structure for an electrode assembly and its associated electrolyte. The metal foil pouch  104  can be bonded to the frame on a top and a bottom surface of the transverse member  156 . The metal pouch can be bonded to the frame  155  on a top surface of the flange, a bottom surface of the flange or combinations thereof. In some embodiments, a board can be inserted in the trough  160  and bonded to the frame  155 . The metal pouch  104  can also be bonded to the bottom of the board after it has been inserted. 
       FIGS. 4A and 4B  are a front view of an unassembled containment structure for enclosing an electrode and associated electrolyte for various embodiments. In  FIG. 4A , frame  165  is similar in shape to frame  155  except in no includes a tray  172 . An electrode, such as a jelly roll electrode and its associated electrolyte can be placed in the tray and coupled to circuitry, such as safety circuitry, as previously described. A metal sheet, such as a metal foil sheet  170  can then be bonded to frame, such as on the flange surfaces to form a containment structure for the electrolyte. If desired, a metal pouch as previously described can be employed, rather than a metal sheet. 
     In  FIG. 4B , frame  175  is similar to frame  165  except the tray  172  now includes a number of apertures. The tray portion  172  can be used to add additional strength rigidity to the containment structure. The apertures can be utilized to reduce the weight of the frame. In general, one or more transverse members of varying dimensions can be added in the tray area and the tray does not have to be formed with the aperture pattern shown in the figure. 
     An electrode assembly can be placed in the tray  172 . In one embodiment, the metal sheet  174  can already be bonded to the frame  175 , such that the apertures are covered, prior to placing the electrode in the tray  172 . After the electrode assembly is placed in the tray  172 , the metal sheet  170  can be bonded to the frame  175  to cover the electrode. During this process, an electrolyte can be added, allowed to diffuse and the containment structure evacuated as previously described. 
       FIG. 5  is a block diagram of a power source distribution scheme for a portable computing device  200 . The portable computing device can be but is not limited to a laptop computer, netbook computer, tablet computer, smart phone, etc. The portable computing device can comprise output devices, such as display, audio devices and audio interfaces, input devices, such as buttons and a touch screen detector and internal devices, such as a processor, memory and storage devices. The internal devices are shown as device components  208 . These devices can be coupled to a portable device casing  210 . 
     The portable computing device  200  can utilize one or more of the portable power sources previously described with respect to  FIGS. 1-4B . In  FIG. 5 , three portable power sources, batteries  202 ,  204  and  206 , are shown. The portable power sources can be the same or different sizes as shown. Each of the batteries,  202 ,  204  and  206  can have different thicknesses. For example, battery  202  can be 3 mm thick while battery  206  can be 6 mm thick. 
     The batteries are shown in different locations but can also be coupled to one another. As previously described, the connector pads can be used to couple batteries together. In particular embodiments, the batteries can be coupled together in a stacked configuration. The stacked batteries do not have to totally overlap when stacked. For example, batteries  202  and  206  can be stacked on top of one another perpendicular orientation as shown in  FIG. 5 . Further, the batteries can be coupled side to side, end to end, side to end. For example, batteries  206  and  202  can be coupled together in an end to side configuration to form a ‘T’ configuration. When coupled together, the batteries can utilize power conditioning circuitry. The power conditioning circuitry can adjust the voltage of each battery depending on its current charge level, how it is coupled to other batteries, charge levels of other batteries and the requirements of associated device components. 
     Typical voltage requirements for the device components  208  can be 3.3 volts, 5 volts, 12 volts and a CPU voltage. A typical voltage output for a single Li-ion polymer battery is about 3.7 Volts. The charging voltage is about 4.2-4.3 Volts. The batteries described herein, such as  204 ,  206  and  208  can also be connected in series. In a series configuration, the output voltage of the connected batteries is increased according to the voltage of each battery in the series. For example, two of the batteries can be connected in series to provide an output voltage of 5 Volts. As another example, four of the batteries can be connected in series to provide an output voltage of 12 Volts. 
     In particular embodiments, two or more of the Li-ion polymer batteries, such as but not limited  202 ,  204 ,  205  and  206  can be connected in a series to produce nominal output voltages between 7-15 Volts. Further, each battery, such as  202 ,  204 ,  205  and  206 , can include multiple battery cells connected in parallel or series. For instance, battery  202  can include two battery cells connected in series. Thus, the nominal voltage output by each battery, such as  202 ,  204 ,  205  and  206 , can vary from battery to battery. Also, as previously described, rather than connecting the batteries in series, the voltages of each battery can be increased/decreased as needed to meet the voltage requirements of a particular device. 
     In particular embodiments, the batteries,  202 ,  204 ,  205  and  206  can be connected to power control  214 . The power control  214  can be located on a central board or can be part of another board, such as main logic board  212 . The power control  214  can include logic, such as charging logic, voltage conversion circuitry, such as voltage regulators and capacitors. The voltage regulators can convert voltages input by the batteries to voltages needed by the device components  208 . In particular, embodiments these can be incorporated into the battery or can be separate from the battery. The capacitors can be used to store and to supply extra power where needed to maintain a steady voltage. 
     In some embodiments, the power control  214  can be configured to dynamically change the output voltages of each battery and/or change how the batteries are connected to one another such that at one time one of the batteries, such as  202 , can be connected to one or more of the other batteries, such as  204 ,  205  or  206 , in a series configuration and at another time, the one battery,  202 , can operate independently and unconnected from the other batteries. The logic in the power control  214  can be configured to dynamically form and break these connections between batteries. 
     Further, in a particular embodiment, when the batteries include circuitry to change their output voltage, the power control  214  can be configured to command a battery to change its output voltage. For instance, the power control  214  can be configured to command battery  202  to change its output voltage from 3.5 Volts to 5 Volts. In other embodiments, the circuitry used to change output voltages can be associated with the power control  214 . Thus, the power control  214  can be configured to receive power from a battery input at a first voltage and change it to a second voltage and then route the power to a particular device. 
     The power control  214  can also include routing circuitry to route power to a device from one battery or combinations of batteries at different times. For instance, at a first time, a first device component can receive power from a first battery, such as  202 , and at a second time, the first device component can receive power from a second battery, such as  204 . In yet other embodiments, certain batteries can be dedicated to power only certain devices. For instance, battery  202  can be dedicated to powering just a display, while batteries  204 ,  205  and  206  can be dedicated to powering the other device components. 
     In another embodiment, different batteries can be dedicated to supplying voltage requirements for certain groups of devices. For instance, battery  202  can be dedicated to supplying power for devices requiring 3.3 Volts, battery  204  can be dedicated to supplying power for device requiring 5 Volts, battery  205  can be dedicated to providing a CPU voltage and battery  206  can be dedicated to supplying devices requiring 12 Volts. The batteries can be sized to meet the needs of the component(s) to which they supply power. Thus, the charge capacity of each battery can vary from battery to battery. 
       FIG. 6  is a flow chart of a method  400  of generating a portable power source. In  402 , a rigid frame configured to partially enclose an electrode assembly, such as a jelly roll assembly for a Lithium ion polymer batter is provided. In  404 , the jelly roll electrode assembly is coupled to electrical contact tabs associated with safety circuitry. Anode and cathode elements of the jelly roll electrode assembly can be attached to these electrical contact tabs. The electrical contact tabs can be integrated into the rigid frame or can be associated with a board including the safety circuitry that is designed to be coupled to the frame. 
     In  406 , a semi-rigid containment structure can be formed that encloses the jelly roll electrode. The semi-rigid containment structure can comprise a metal foil bonded to the rigid frame. The frame is rigid as compared to the metal foil. The metal foil can include a laminate layer that can be heat sealed to the metal foil. In particular embodiments, the metal foil can be provided as a metal pouch or a metal sleeve that is slid over the frame and the jelly roll electrode. 
     In  408 , a liquid or gel electrolyte can be added to the semi-rigid containment structure and allowed to diffuse over the jelly roll electrode. In one embodiment, the frame can comprise an injection port that provides access to an interior of the semi-rigid containment structure. The injection port can be configured to allow electrolyte to be injected into the containment structure. The direction of the injection can be aligned with the axis of rotation of the electrode jelly roll. 
     In  410 , the semi rigid containment structure can be vented in some manner. For example, a cut can be made in the metal foil of the semi-rigid containment structure. As another example, a hollow needed could be inserted through the injection port. In  412 , a low pressure condition can be applied to evacuate the semi-rigid containment structure. For instance, the device can be placed under vacuum conditions. In one embodiment, the rigid frame can include a valve or an interface that allows gasses to be evacuated from the semi-rigid container. 
     In  414 , after the low pressure condition has been applied, it may be necessary to reseal the semi-rigid containment structure. For instance, when a cut is made in the metal foil to vent the containment structure, the cut can be resealed. As another example, an injection port or valve can be covered with an epoxy or some other sealant to permanently seal the device. 
     The advantages of the invention are numerous. Different aspects, embodiments or implementations may yield one or more of the following advantages. The present invention provides a containment structure for an electrode an associated electrolyte used in a portable power source, such as a battery. The containment structure can comprise a metal foil pouch coupled to a rigid frame. One advantage of the invention is that the containment structure can prevent undesired bending of the electrode, such as an electrode jelly roll. This feature can allow a portable power source including the containment structure to be utilized without additional packaging, such as enclosing the containment structure in a hard-shell casing. Many features and advantages of the present invention are apparent from the written description and, thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.

Metadata:
Filing Date: 20100301
Publication Date: 20130827
Grant Date: 20130827
Priority Date: 20100301
Inventors: MURPHY R. SEAN
WILSON, JR. THOMAS W.
Assignee: APPLE INC
CPC Classifications: [{"code": "H01M50/55", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/119", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/124", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/55", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/119", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/124", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/119", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/55", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/124", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M10/42", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02P70/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M50/267", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01M50/267", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01M10/425", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02E60/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01M10/0525", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 43827089