PATENT DOCUMENT

Publication Number: US-11476493-B2
Application Number: US-202016818017-A
Country: US
Kind Code: B2

Title: Battery can

Abstract:
Aspects of the present disclosure involve various battery can designs. In general, the battery can design includes two fitted surfaces oriented opposite each other and seam welded together to form an enclosure in which a battery stack is located. To form the enclosure, the two fitted surfaces are welded together along the large perimeter. Other swelling-resisting advantages may also be achieved utilizing the battery can design described herein including, but not limited to, the ability to modify one or more can wall thicknesses to control a pressure applied to the battery stack by the can, overall reduction in wall thickness of the can through the use of stronger materials for the can surfaces, additional supports structures included within the can design, and/or bossing or other localized thinning of surfaces of the can.

Claims:
What is claimed is: 
     
       1. A battery comprising:
 an enclosure; and 
 a battery stack disposed within the enclosure; 
 wherein a surface of the enclosure forms a plurality of indentations that extend into an interior of the enclosure to increase the structural rigidity of the enclosure. 
 
     
     
       2. The battery of  claim 1 , wherein the enclosure comprises at least one electrical connection and an electrolyte fill hole. 
     
     
       3. The battery of  claim 1 , wherein the enclosure comprises a first portion and a second portion, wherein a wall of the first portion is welded to a wall of the second portion to form a seam around a perimeter of enclosure. 
     
     
       4. The battery of  claim 3 , wherein the enclosure further comprises a weld protective backing disposed on an inner surface of the enclosure, the weld protective backing configured to prevent at least some heat from entering the enclosure during a welding process. 
     
     
       5. The battery of  claim 4  wherein the weld protective backing comprises at least one of a metal material, a ceramic material, and a polymer material. 
     
     
       6. The battery of  claim 3 , wherein the battery stack comprises a localized electrode reduction feature corresponding to the seam around the perimeter of the enclosure to increase a gap between the seam and the battery stack. 
     
     
       7. The battery of  claim 1 , further comprising a support column extending across the enclosure. 
     
     
       8. The battery of  claim 7 , wherein an end of the support column comprises a threaded bore configured to receive a fastener. 
     
     
       9. The battery of  claim 1 , wherein a thickness of the enclosure is about 100 μm. 
     
     
       10. A battery comprising:
 an enclosure formed of metal comprising a bottom portion and a top portion, wherein the bottom portion is welded to the top portion at a seam; 
 a battery stack disposed within the enclosure; and 
 wherein the bottom portion comprises a plurality of indentations formed on the bottom portion that extend into an interior of the enclosure to increase a structural rigidity of the enclosure. 
 
     
     
       11. The battery of  claim 10 , further comprising a weld protective backing disposed on an inner surface of the enclosure, the weld protective backing configured to prevent at least some heat from entering the enclosure during a welding process. 
     
     
       12. The battery of  claim 11 , wherein the weld protective backing comprises at least one of a metal material, a ceramic material, and a polymer material. 
     
     
       13. The battery of  claim 10 , wherein the battery stack comprises a localized electrode reduction feature corresponding to the seam to increase a gap between the seam and the battery stack. 
     
     
       14. The battery of  claim 10 , further comprising a support column extending between the bottom portion and the top portion. 
     
     
       15. The battery of  claim 14 , wherein an end of the support column comprises a threaded bore configured to receive a fastener. 
     
     
       16. The battery of  claim 14 , wherein the battery stack comprises a hole, and wherein the support column is disposed within the hole and extends through the battery stack. 
     
     
       17. The battery of  claim 10 , further comprising an additional plurality of indentations formed on the top portion that extend into an interior of the enclosure to further increase the structural rigidity of the enclosure. 
     
     
       18. The battery of  claim 10 , wherein the bottom portion comprises a base having a first thickness and a wall projecting from the base, the wall having a second thickness, wherein the first thickness is greater than the second thickness. 
     
     
       19. The battery of  claim 10 , wherein a thickness of the bottom portion is about 100 μm. 
     
     
       20. The battery of  claim 10 , wherein a thickness of the top portion is about 100 μm.

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/088,967 entitled “BATTERY CAN”, filed on Apr. 1, 2016, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 62/142,930 entitled “BATTERY CAN”, filed on Apr. 3, 2015, each of which is incorporated by reference in its entirety herein. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to battery systems, and more specifically to battery cans. 
     BACKGROUND 
     Battery performance and lifecycles in mobile electronic and other types of computing devices are an ever increasing concern. Particularly as mobile devices become smaller while the processing power and demands on such devices increase, the ability of the battery to provide the necessary power needs to the device increases in importance and competes with the desire to reduce the overall size of the device. Obtaining more power from the battery while restraining the overall size of the battery to fit within the mobile device is a continual challenge. It is with these and other issues in mind that various aspects of the present disclosure were developed. 
     SUMMARY 
     In one aspect, the disclosure is directed to a battery can that provides increased pressure on the battery stack for higher battery performance. In general, the battery can design can include two fitted surfaces oriented opposite each other, and welded together to form an enclosure in which a battery stack is located. In various aspects, the fitted surfaces can have an overlapping conformation. The two fitted surfaces can be welded together along the perimeter. The battery can may have any shape or size, giving the battery assembly substantial form factor flexibility. 
     In a further aspect, the disclosure is directed to a battery can assembly that includes a first portion having a first surface and one or more first walls extending from the first surface, and a second portion having a second surface and one or more second walls extending from the second surface. The length and width of the first surface can be larger than the length and width of each of the one or more first walls. A battery stack is disposed between the first and second portions. 
     In a further aspect, the disclosure is directed to a battery cell including a battery enclosure and a battery stack. The battery enclosure includes a bottom surface, a top surface, and at least one wall connecting the bottom surface to the top surface. The battery enclosure encloses the battery stack. At least one pressure feature is configured to apply a pressure force to the battery stack within the battery enclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Although the following figures and description illustrate specific embodiments and examples, the skilled artisan will appreciate that various changes and modifications may be made without departing from the spirit and scope of the disclosure. 
         FIG. 1  is a first isometric view of a battery can using two dish or clamshell shaped outer surfaces. 
         FIG. 2  is a second isometric view of the battery can of  FIG. 1 . 
         FIG. 3A  is an isometric view of a battery can using two rectangular pieces seam welded together. 
         FIG. 3B  is a cross-section view of the battery can of  FIG. 3A  along view line AA. 
         FIG. 4  is an isometric view of another battery can using two portions seam welded together along a Z-X-axis perimeter of the can. 
         FIG. 5  is a cross-section view of a conventional prismatic battery can. 
         FIG. 6  is a cross-section view of a battery can illustrating varying wall thickness of the can enclosure. 
         FIG. 7  is a cross-section view of a battery can illustrating a plurality of support structures within the can. 
         FIGS. 8A-8F  are illustrations of several support structures within a battery can. 
         FIGS. 9A and 9B  are a cross-section view and top view of a battery can illustrating a first bossing feature on the top surface of the battery can. 
         FIGS. 10A and 10B  are a cross-section view and bottom view of a battery can illustrating a localized thinning feature on the top surface of the battery can. 
         FIG. 10C  is a cross-section view of a battery can illustrating the can mounted on a surface of a computing device. 
         FIG. 10D  is a top view of a second type of an embossing feature on an outer surface of a battery can. 
         FIG. 10E  is a cross-section view of a battery can with the second type of embossing feature on the outer surface of the battery can. 
         FIG. 10F  is a top view of a third type of an embossing feature on an outer surface of a battery can. 
         FIG. 10G  is a top view of a fourth type of an embossing feature on an outer surface of a battery can. 
         FIG. 10H  is an isometric view of a fifth type of embossing feature on an outer surface of a battery can. 
         FIG. 11  is a cross-section view of a battery can illustrating a localized electrode reduction feature of the battery stack of the can. 
         FIG. 12A  is a cross-section view of a battery can illustrating a first embodiment of a protective backing feature along a seam of the can. 
         FIG. 12B  is a cross-section view of a battery can illustrating a second embodiment of a protective backing feature along a seam of the can. 
         FIG. 13A  is a cross-section view of a battery can surface illustrating a first embodiment of an electrolyte fill hole design of the can. 
         FIG. 13B  is a cross-section view of a battery can surface illustrating a second embodiment of an electrolyte fill hole design of the can. 
     
    
    
     DETAILED DESCRIPTION 
     As noted above, aspects of the present disclosure involve a battery can design that provides increased pressure on the battery stack for higher battery performance. In general, the battery can design can include two fitted surfaces oriented opposite each other, and welded together to form an enclosure in which a battery stack is located. In various aspects, the fitted surfaces can have an overlapping conformation. To form the enclosure, the two fitted surfaces can be welded together along the perimeter, referred to herein as the X-Y perimeter of the battery package or “can”. The battery can and battery assembly can be used in conjunction with any battery variation, including any lithium ion battery variation 
     In various aspects, battery can may have any shape or size, giving the battery assembly substantial form factor flexibility. For example, the battery can may be formed to fit within a prescribed area within a device, such as a computing device. This form may include any number of sides, angles, and/or shapes to account for one or more other components within the computing device casing. However, any shape or size of the battery cell is contemplated. Also, in various battery can embodiments described herein add more energy to the battery can than previous variations of lithium ion battery cells. This added energy may increase the performance of the battery over the lifetime of the battery cell. 
     Through this particular battery can design, several advantages may be obtained over conventional battery designs. For example, the battery can enclosure formed from the fitted surfaces may reduce the gap (i.e. a clearance or tolerance) between the battery stack and the can surface over conventional prismatic battery designs. The reduced gap can result in a more intimate and/or constant contact between battery and the battery can. This reduction in the gap aids in resisting swelling of the battery stack during the lifetime of the battery. Such resistance to the swelling of the battery stack may increase the performance, durability, and useful life of the battery, as well as protect the device in which the battery can is mounted. Other advantages of swelling-resistance may also be achieved utilizing the battery can design described herein including, but not limited to, the ability to modify one or more wall thicknesses of the battery can to increase pressure applied to the battery stack by the can, overall reduction in wall thickness of the can through the use of stronger materials for the can surfaces, additional support structures included within the can design, and/or bossing or other localized thinning of surfaces of the can. Because the battery can design herein includes two fitted surfaces welded together along the large X-Y perimeter rather than a cup shape with a lid welded along a small X-Z end of previous battery can designs, several design additions become available to strengthen the can and improve the overall performance and lifetime of the battery. 
     Additional features of the battery can design may also be considered and/or included to improve the performance of the battery can in response to the fitted can design. For example, the can design may include a welding shield adjacent to or near the welding seam between the two surfaces of the battery can. Such a welding shield may protect the battery stack from damage during the conjoining procedure of the two surfaces of the can design. Other features include improved electrolyte fill hole design to account for thinner wall thicknesses in the battery can due to one or more of the improvements noted above. Such fill hole designs may be included with one or more feedthrough structures contained in one edge of one of the fitted surfaces that provide electrical connections to the battery stack within the can. Additional features of the can designs are further discussed herein that further improve the overall performance and lifetime of a battery stack within the battery can. 
     The various designs and methods disclosed herein provide for battery cans for any type of electrical device. It will be appreciated that, although some of the example implementations described herein involve the battery providing power to a type of electrical device, such as a cell phone or laptop computer, the battery designs and methods described herein may apply to any type of electrical device, computing system or mobile device where power from a battery may be desired to power the device. The battery cans and enclosures can be used for any battery configuration (e.g. battery stack) known in the art. As used herein, the term “battery stack” may include, but is not limited to, a stacked-electrode or wound jelly roll configuration. Further, any type of lithium ion cell may be used with the embodiments and designs of the battery can described herein. 
       FIGS. 1 and 2  are isometric views of a battery can using two dish or clamshell shaped outer surfaces. In particular, the battery can  100  includes a first portion, or upper portion  102 , that has an optionally flat or semi-flat surface  110  and four walls  112  that extend from the flat or semi-flat surface. In general, the dimensions (e.g., width and length) of the flat or semi-flat surface  110  are larger than the dimensions of the walls  112  such that the four walls are smaller in area than the larger flat or semi-flat surface to form a rectangular-shape with an opening along one of the larger surfaces of the rectangle. The regions of the first portion  102  where the surface  110  meets the four walls  112  may form an edge. In some embodiments the edge can have a right angle or may be rounded. Similarly, the regions of the first portion  102  where the four walls  112  meet may form a corner; in some embodiments the corner may be a right angle, an obtuse angle, an acute angle or may be rounded. In addition, one or more feedthroughs  106  may be located on a wall  112  of the first portion  102 . The feedthroughs  106  provide electrical connections to a battery stack contained within the battery can  100 . In addition, one or more fill holes  108  may also be located on a wall  112  of the first portion  102 . The fill hole  108  may or may not be on the same wall  112  of the first portion  102  as the feedthroughs  106 . 
     The battery can  100  may also include a second portion  104 . In one embodiment, the second portion  104  includes a similar shape as the first portion  102 , namely, a flat or semi-flat surface  114  and four walls that extend from the surface to form a rectangular-shape with an opening along one of the larger surfaces of the rectangle. In the embodiment, the length and width of the flat or semi-flat surface  114  may include slightly smaller dimensions than corresponding dimensions of the flat or semi-flat surface  110  of the first portion  102 . Thus, when mated, the walls of the second portion  104  fit inside the walls  112  of the first portion  102  to form a box-like enclosure. In another embodiment, the second portion  104  includes the flat or semi-flat surface  114 . In general, the dimensions of the flat or semi-flat surface  114  of the second portion  104 , in this embodiment, are the same or similar to the flat or semi-flat surface  110  of the first portion  102  such that, when mated, the first and second portion of the battery can form a box-like enclosure for housing a battery stack. 
     As should be appreciated from the figures, before the portions  102 ,  104  of the battery can  100  or battery can are mated, the portions may be mated along an axis perpendicular to the larger surface  110  of the first portion and/or the larger surface  114  of the second portion. As shown in  FIG. 3A , this axis perpendicular to the larger surfaces  110 ,  114  of the portions is referred to herein as the “z-axis” of the battery can  100 . In particular,  FIG. 3A  is an isometric view of a battery can  100  using the two portions  102 ,  104  welded together to form an enclosure. Similar to the embodiments discussed above, the battery can  100  design of  FIG. 3A  includes a first portion  102  and a second portion  104 . The first portion  102  includes one or more feedthroughs  106  and a electrolyte fill hole  108 . Further, the second portion  104  engages with the first portion  102  to form an enclosure for a battery stack. As shown in relation to the coordinate axis of  FIG. 3A , the flat surface  110  of the second portion  104  (and the flat surface  114  of the first portion  102 ) lie or partially lie in the X-Y plane, with the walls of the first portion and the second portion lying or partially lying in the Z-plane. As should be appreciated, the coordinate axis of  FIG. 3A  is used merely as a reference tool for the battery can  100  design and should not be considered to be indicative of any type of direction or orientation of the battery can in relation to an electronic device utilizing the battery can. 
       FIG. 3B  is a cross-section view of the battery can  100  of  FIG. 3A  along view line AA. Similar to the embodiments discussed above, the battery can  100  or can includes a first portion  102  with a semi-flat surface  102  and walls  112  projecting from the semi-flat surface. In general, the semi-flat surface  110  may lie partially in the X-Y plane with the walls  112  lying along the Z-axis at least partially perpendicular to the semi-flat surface. As discussed in more detail below, the semi-flat surface  110  and the walls  112  of the first portion  102  may be of a particular thickness. Similarly, the battery can  100  includes a second portion  104  with a semi-flat surface  114  lying partially in the X-Y plane and walls  116  projecting from the semi-flat surface lying along the Z-axis at least partially perpendicular to the semi-flat flat surface. Also, the semi-flat surface  114  and the walls  116  of the second portion  104  may also be of a particular thickness. 
     The first portion  102  and the second portion  104  are oriented with respect to each other such that the semi-flat surfaces  110 ,  114  and the walls  112 ,  116  form an enclosure. In the particular embodiment illustrated in  FIG. 3B , the walls  116  of the second portion  104  are outside the walls  112  of the first portion  102  in relation to the center of the enclosure when the portions are mated. In other embodiments, the walls  116  of the second portion  104  may be inside the walls  112  of the first portion  102 , such as in the embodiment of the can  100  illustrated in  FIGS. 1 and 2 . In yet another embodiment, the walls  112 ,  116  of the portions  102 ,  104  may lie in the same plane and meet at the end of the walls to form the seam of the enclosure. Regardless of the embodiment, a battery stack  302  may be included in the enclosure formed by the first portion  102  and the second portion  104 . In general, the battery stack  302  is a single long sandwich of positive electrode, separator, negative electrode and separator folded into a stack to fit within the battery enclosure. To provide power from the battery, lithium ions typically move from the negative electrode to the positive electrode during discharge and back when charging. Further, as discussed in more detail below, an electrolyte is introduced into the battery pack  100  which allows for the ionic movement between the electrodes. 
     As discussed, the battery can design  100  includes two portions  102 ,  104  with semi-flat surfaces  110 ,  114  in an X-Y plane with the walls extending along a Z-axis. Thus, to create the enclosure, the two portions  102 ,  104  may be brought together along the Z-axis and a weld seam may be created around a perimeter in the X-Y plane to seal the enclosure. This orientation of the seam is an improvement over conventional designs for prismatic battery cans. For example,  FIG. 4  is an isometric view of a battery can using two portions welded together in a Z-X-plane around the perimeter of the can. In particular, the battery can  426  includes a rectangular-shaped portion  420  that is open on one end of the portion. A second portion  422  is attached to the open end of the first portion to create the battery can enclosure. In this example, the seam is in the Z-X plane around the perimeter of the can  426 . As shown, the battery can  426  separates or comes together along the Y-axis such that a battery stack may be inserted into the first portion  420  and the lid or second portion  422  is placed on the first portion and the can is closed. However, as described in more detail below, this particular battery can design  426  has several disadvantages in comparison to the battery can  100  that includes a mating seam around the perimeter of the can in the X-Y plane. In particular, due to the nature of the construction of the first portion  420  of conventional battery can  426  of  FIG. 4 , several aspects of the thickness and dimensions of the walls of the first portion in relation to the battery stack included in the battery can enclosure may limit the effectiveness and performance of the battery can. 
     One battery performance advantage obtained through the battery can design of  FIGS. 1-3B  is a reduced clearance gap between the dry battery stack  302  and the second can portion  104 . In the more traditional battery can design  426  (such as that shown in  FIG. 4 ), the battery stack of the battery is slid into the enclosure. However, due to the inconsistencies in the wall thickness of the conventional battery can  426 , it is often the case that a large gap exists between the battery stack and the walls of the battery can  426 . In contrast, the battery can design  100  of  FIGS. 1-3B  reduces the gap between the battery stack  302  and the walls of the battery can. In particular, because the first portion  102  and the second portion  104  are mated along the Z-axis, the wall tolerances of the larger semi-flat surfaces between the can and the battery stack may be more closely controlled and/or reduced than in previous can designs. Large variations in tolerance between the can and the battery stack of the larger semi-flat surface may increase damage to the battery stack as the stack swells during operation of the battery. The additional control over the wall tolerances of the first portion  102  and the second portion  104  achievable through the battery can design discussed herein may allow for the stack to conform more closely to the interior shape and dimensions of the battery can  100  enclosure. This includes a reduced gap between the battery stack  302  and the inner wall surfaces of the battery can. For example and as shown in  FIG. 3B , a small gap  304  between the battery stack  302  and the inner surface of the large portion  114  of the second portion  104  of the battery can design  100  may be obtained. Similar reduced gaps may also be present between the battery stack  302  and each of the inner surfaces of the battery can  100 . Additionally, as the battery stack  302  swells, either when the electrolyte is introduced into the battery can enclosure or during use of the battery stack, the gap between the stack and the inner surfaces of the can design may be further decreased. In some embodiments, the battery stack  302  may be in contact with one or more of the inner surfaces of the battery can  100  enclosure. 
     The reduced gap  304  between the battery stack  302  and the inner surfaces of the enclosure of the battery can  100  can be used to increase pressure on the battery stack during use of the battery. In general, increased pressure on the battery stack  302  as the battery swells during use may prolong the life of the battery cell and, thereby, increase the performance of the battery. Thus, a reduced gap between the battery stack  302  and the inner surfaces of the enclosure of the battery can  100  may help contain the amount of swelling of the battery stack during use. Additional features may also be included in the battery can design  100  to maintain or increase the pressure placed on the battery stack  302  of the battery cell, as discussed in more detail below. 
     In addition to reducing a gap between the battery stack  302  and the inner surfaces of the enclosure of the battery can  100 , the battery can design can provide a more uniform pressure on the stack. In particular, because the direction of the draw of the battery can  100  is in the Z-axis direction (which is the same direction as the swell of the battery stack  302 ), the pressure distribution along the battery stack is can be more uniformly applied. This is in contrast to conventional prismatic cell designs. For example,  FIG. 5  is a cross-section view of a conventional prismatic battery can  500 . As can be appreciated from the cross-section, swelling in the Z-axis direction of the battery pack  502  within the enclosure of the battery can  500  may cause pressure on the stack to be non-uniform. In particular, the battery stack  502  may swell more on the right side of the battery can  500  shown than on the left side due to irregularities in the can wall construction process. In contrast, the can design  100  of  FIGS. 1-3B  provides a more uniform pressure applied to the battery stack  302 . More particularly, because the portions  102 ,  104  of the battery design  100  are mated along the Z-axis, the construction of the inner surface of the first portion and the second portion may be more closely controlled. This results in more uniform thickness along the semi-flat larger surface  110 ,  114  of the portions  102 ,  104  that may be closer to parallel to each other when compared to the inner surfaces of the prismatic battery can  500  of  FIG. 5 . Thus, as the battery stack  302  swells, the pressure applied to the battery stack by the inner surfaces of the battery can  100  is more uniform than in conventional prismatic battery can designs. 
     As mentioned, the design of the battery can  100  described herein allows for more control of the construction of the battery can. For example, the design  100  allows for the ability to modify the thickness ratios of the walls of the battery can. In one particular embodiment illustrated in  FIG. 6 , the semi-flat surface  110  of the first portion  102  and the semi-flat surface  114  of the second portion  104  are thicker than the walls  112 ,  116  of the can design  600 . The thicker larger surfaces  110 ,  114  may provide a stronger resistance to the Z-swelling of the battery stack  302  while the thinner walls  112 ,  116  provide for more cell capacity. In the embodiment illustrated in  FIG. 6 , the thinner walls  112 ,  116  of the can  600  may be achieved by tapering the thickness of the walls along the length of the walls. In general, however, the thickness of the walls of the can design  600  may be any thickness as desired in response to battery performance and overall cell capacity. 
     Similarly, the thickness of any of the walls  112 ,  116  or the larger, semi-flat surfaces  110 ,  114  of the first portion  102  and the second portion  104  of the battery can  100  may be thinner than in conventional prismatic battery can designs. In various aspects, by utilizing strong materials such as stainless steels or titanium to form the first portion  102  and/or second portion  104 , the thicknesses of the portions may be reduced to increase the overall cell capacity when compared to conventional prismatic battery cell designs. One consideration when determining the thickness of the portions  102 ,  104  of the battery can  100  is the ability of the battery to draw energy from the battery stack  302 . In general, as the thickness of the walls of battery increase, there can be a reduction in the potential energy draw from the battery stack  302 . However, reducing the thickness of the wall should be balanced with the fact that thinner walls may not provide adequate strength for applying pressure to the battery stack  302  to reduce swelling of the stack. The balance between the ability to draw energy from the stack while still providing adequate strength may be considered when determining the thickness of the portions  102 ,  104  of the battery can  100 . In one embodiment, the battery can  100  may include a can tolerance of +/−0.1 mm in the X-Y plane and a +/−0.05 mm along the Z-axis. However, the wall thicknesses of the portions of the can  100  may be any dimension as determined by a designer of the battery can. 
     Additional features to apply a pressure to the battery stack  302  or otherwise resist battery stack swelling may also be included in the battery can  100  design. Such features may be used in addition to the other features discussed herein or used separately from one or more other features. One such feature includes one or more support columns located within the battery can  100  enclosure.  FIG. 7  is cross-section view of a battery can  700  illustrating a plurality of support structures  702  within the can. In general, the can  700  includes similar portions as described above, namely a first portion  102  with a larger semi-flat surface  110  and walls  112  and a second portion  104  with a larger semi-flat surface  114  and walls  116 . Included in the enclosure created by the first portion  102  and the second portion  104  is a battery stack. A seam connecting the first portion  102  and the second portion  104  may be present around the X-Y perimeter of the can  700 , as described above. 
     Also mentioned above, the battery stack  302  may swell along the Z-axis during the lifetime of the battery cell  700 . To resist or otherwise account for the stack  302  swelling, the battery can  700  may include one or more support columns  702  between the large surface  110  of the first portion  102  and the large surface  114  of the second portion  104 . The support columns  702  may connect or otherwise attach to an inner portion of the larger surfaces  110 ,  114  such that, as the battery stack  302  swells, the columns prevent the larger surfaces from bowing outward from the can enclosure. The support columns  702  may attach to the inner portions of the larger surfaces  110 ,  114  through any known or hereafter developed method, including but not limited to, welding, adhesive, screws, and the like. 
     In general, the support columns  702  extend through the battery stack  302  between the semi-flat larger surfaces  110 ,  114  of the can  700 . Thus, one or more holes may be made within the battery stack  302  at the location of the one or more support columns  702 . During construction of the battery cell, the battery stack  302  is placed into the enclosure of the battery can  700  around one or more of the support columns  702 . The support columns may then be attached to one or more of the inner portions of the large surfaces  110 ,  114 . In one embodiment, the support columns  702  may be coated with an insulating material to prevent electrical contact between the battery stack  302  and the support column  702 . In other embodiments, the support columns  702  are in electrical communication with the battery stack  302  and the larger surfaces  110 ,  114  of the can  700 . In another embodiment, the support columns  702  may be hollow and extend to the outer portion of the larger surfaces  110 ,  114  of the battery can  700 . Thus, each of the larger surfaces  110 ,  114  of the battery can  700  may include holes that extend through the battery can. These holes (with or without threads) may be used as holes for screws to mount the battery cell  700  into a device or to run coolant through to aid in maintaining a proper operating temperature of the battery cell. In general, the holes through the battery cell  700  created by the support columns  702  may be filled or unfilled for any purpose. 
       FIGS. 8A-8F  are illustrations of several support structures within a battery can. The examples illustrated in  FIGS. 8A-8F  are but some of the possible configurations that may be used for the support columns  702  described above. For example, the support column  702  of  FIG. 8A  includes the first portion  102  and the second portion  104  of the battery can  700  described above with relation to  FIG. 7 . The support column  802  includes a column that extends from the first portion  102  and is connected or adhered to the inner surface of the second portion  104 . In one particular example, the column  802  may be spot welded to the inner surface. In another example of the support column  804  illustrated in  FIG. 8B , the column  804  extending from the first portion  102  may extend through the second portion  104  and ending at the outer surface of the second portion. As described above, the support columns  802 ,  804  may be solid or hollow. 
     In the embodiment illustrated in  FIG. 8C , the support structure  806  includes a column  812  extending from the second portion  104  and a corresponding hollow cylinder  814  extending from the first portion  102 . The column  812  from the second portion  104  is oriented to slide into the cylinder  806  of the first portion  102  to create the support structure  806 . Similar to above, the column  812  may be solid or hollow and may or may not extend through the first portion  102 .  FIG. 8D  illustrates yet another embodiment of the support column  702  of the battery can  700 . In particular, the can includes a hollow cylinder  808  from the outer portion of the first portion  102  to the outer portion of the second portion  104 . Any joint between where the hollow cylinder  808  meets the first and second portion may be spot welded or otherwise attached to create the hole through the battery can. In a similar structure  810  illustrated in  FIG. 8E , the first portion  102  includes a hollow cylinder  816  that extends towards the second portion  104 . The second portion  104  includes a similar hollow cylinder  818  that extends toward the first portion. The cylinder  818  of the second portion  104  is sized to fit into the cylinder  816  of the first portion  102 . When brought together such that the cylinder  818  of the second portion  104  is inside the cylinder  816  of the first portion  102 , a support column  810  creates a hole through the battery can. Further, as discussed above, a hollow support structure may be utilized as holes for screws to mount the battery cell  700  into a device. One particular example of the hollow support structure utilized for a screw hole through the battery cell is illustrated in  FIG. 8F . It should be appreciated the support structures of  FIGS. 8A-8F  are but some examples of the many types of support columns  702  that may be used in conjunction with the battery can  700  design discussed herein. 
     The battery can  100  may include still other features that may help in responding to swelling of the battery stack  302 . For example and as shown in  FIGS. 9A and 9B , the battery can  900  may include a bossing feature  902  on at least one surface of the battery can to apply pressure to the battery stack  302  contained within the can enclosure, even during deformation of the can due to battery stack swelling. In the embodiment shown in  FIGS. 9A and 9B , the bossing feature  902  is located on the larger surface  114  of the second portion  104 . However, the bossing feature  902  may be located on any surface of the battery can  900 . In general, the bossing feature  902  includes biasing at least a portion of a surface of the battery can  900  to extend into the enclosure of the can to apply pressure to the battery stack  302 . As seen in the top view of the battery can  900 , the bossing feature  902  may be shaped to approximate the shape of the battery stack  302  to which the bossing feature applies pressure. However, the bossing feature  902  may be any shape on the surface or surfaces of the battery can  900 . 
     Similarly and as shown in  FIGS. 10A and 10B , the battery can  1000  may include one or more localize thinning features  1002  in one or more surfaces of the battery can. In the embodiment shown in  FIGS. 10A and 10B , the thinning feature  1002  is located on the larger surface  110  of the first portion  102  to provide a location and/or make room in the larger surface for one or pressure sensitive adhesives (PSAs) that are utilized to mount the battery can in an electronic device. As shown in  FIG. 10C , the thinning feature  1002  provides a thinner portion  1002  of the battery can surface for mounting or otherwise attaching the battery cell  1000  to a surface  1004  of a computing device. In the example shown, the battery cell  1000  is mounted to the computing device surface  1004  through one or more PSAs  1006 . However, the thinning feature  1002  may be located on any surface of the battery can  1000 . In another example, the thinning feature  1002  may be located on the larger surface  114  of the first portion  104  to form one or more ribs or other features in the surface of the battery can  1000 . In general, the thinning feature  1002  may be created on the surface of the battery can  1000  through any method known or hereafter developed for thinning a surface of a device, such as ablation, coining, etching, and the like. 
     In yet another embodiment, one or more of the outer surfaces of the can may include a bossing feature to improve the structural integrity of the can sides and resist twisting and warping of the can sides. In particular, the battery can may be constructed of thin stainless steel sides, such as 75 μm in some embodiments. The thinness of the battery can may cause the can to twist or warp such that the can may not retain its intended shape after manufacturing. Such warping may be caused by the expansion of the battery can as discussed above. Further, warping may cause issues during the welding of the two halves of the battery can, leading to improper welds. By improving the structural rigidity of the battery can sides, these issues may be avoided. 
       FIG. 10D  is a top view of a particular pattern of an embossing feature on an outer surface of a battery can to improve the structural rigidity of the sides of the can. In the example illustrated, a pattern of dimples  1052  is included on the top surface of the can  1050 . Although illustrated on the top surface of the can  1050 , it should be appreciated that such a bossing feature may be included on any outer surface of the can to increase the structural rigidity. Further, while the dimples  1052  of the embossing feature illustrated in  FIG. 10D  are illustrated as uniformly spread apart, the embossing feature may be present on the surface in any manner, including disposing the bossing feature on only a portion of the surface. Other types of embossing features are discussed below and illustrated in  FIGS. 10F-10H . 
       FIG. 10E  is a cross-section view of a battery can with the dimpled embossing feature  1052  on the outer surface of the battery can  1050 . As shown, the dimples  1052  of the embossing feature cause one or more indentions into the interior of the can assembly to increase the area moment of inertia in the thickness direction of the can  1050 . Through this increase in area moment in the thickness direction, the can&#39;s area moment of inertia is also increased thereby improving the structural rigidity of the sides of the can assembly  1050 . In this manner, twisting or warping of the battery can  1050  may be reduced. 
       FIG. 10F  is a top view of a first type of a beaded embossing feature  1058  on the outer surface of a battery can  1054  and  FIG. 10G  is a top view of a second type of a beaded embossing feature  1060  on the outer surface of a battery can  1056 . The beaded designs included in the illustrations are just some of the possible beaded designs that may be included in the can surface to improve the structural integrity of the can. 
     In another example,  FIG. 10H  shows an isometric view of a hexagonal pattern embossing feature  1064  on an outer surface of a battery can  1062 . Other possible designs are also contemplated, such as squares, triangles, and the like. In addition, other embossing features, such as one or more ribs along the surface, may be utilized with the battery can. In general, any type and number of embossing features may be included on the outer surface of the battery can to improve the structural integrity of the battery can to resist warping and/or twisting of the battery can sides. It should be appreciated that such embossing features are not limited to the examples described herein. 
     Further, the embossing feature may be included on a battery can of any shape and size. For example, the battery can surface  1062  illustrated in  FIG. 10H  may include a small portion that extends out from the main portion of the battery can. Also, in some embodiments, the embossing feature may be associated with one or more features of an enclosure in which the battery can is mounted. For example, a computing device may include an enclosure on the interior of the device. The interior surface of the computing device may include one or more features, such as beaded features that are complimentary to the beaded embossing features illustrated in  FIGS. 10F and 10G . In other words, the battery can may include an embossing feature that mirrors or compliments a similar embossed feature on the interior surface of the enclosure in which the battery can is located. By including an embossing feature on the outer surface of the battery can that mirrors and mates with a corresponding feature on the interior surface of an enclosure, the space consumed by the battery can within the enclosure may be reduced while increasing the rigidity of the battery can. In addition, friction between the embossing feature on the battery can and the corresponding feature on the enclosure may act to hold the battery can in place within the enclosure. 
     As mentioned above, the battery can  100  design described herein may include a seam around an X-Y perimeter of the can. This seam is generally the location in which the first portion  102  and the second portion  104  of the can design meet and are sealed to create the battery cell. In one embodiment, this seal around the seam is created through a laser welding procedure that welds the two portions together. However, the battery stack  302  located within the enclosure of the battery can  100  may be sensitive to the heat used to create the seam around the battery can. Thus, the battery can  100  may include one or more features that account for the heat of the welding process to protect the battery stack  302  within the battery can  100 . 
     For example,  FIG. 11  is a cross-section view of a battery can  1100  illustrating a localized electrode reduction feature  1102  of the battery stack  302  of the can  1100 . In general, the localized electrode reduction feature  1102  includes a reduction of the electrodes of the battery stack  302  directly behind or near the weld seam  1104  of the battery can  1100 . The reduction  1102  increases the gap between the inner surface of the enclosure where the weld seam  1104  is located around the perimeter of the battery can  1100 . This reduction  1102  to the electrodes of the battery stack  308  may be limited to the area near the weld seam  1104  to minimize the reduction in the capacity of the battery cell. 
     In addition, the battery can may include a welding shield or backing located in or near the enclosure around the weld seam to block or minimize the light/heat entering the enclosure during the welding process. For example,  FIG. 12A  is a cross-section view of a battery can  1200  illustrating a first embodiment of a protective backing feature  1202  located along a back of a weld seam  1204  of the can. In one embodiment, the backing feature  1202  is a metal backing that absorbs at least some of the light/heat/radiation of the laser welding process. The metal backing may be joined to the interior surface of the enclosure of the battery can  1200  at or near the weld seam  1204 . In another embodiment, the backing feature  1202  is a ceramic material that absorbs the laser radiation and is generally more conductive to provide thermal insulation between the weld seam  1204  and the battery stack  302 . In other embodiments, backing feature  1202  material may be a polymer material that provides a similar thermal insulation than the ceramic backing. It yet another embodiment, the backing feature  1202  may include two or more materials. For example, the backing feature  1202  may include a metal portion to absorb light/heat/radiation from the welding process with a ceramic or polymer portion to hold the metal portion in position near the seam  1204 . It should be appreciated, however, that the embodiments provided herein are merely examples and the backing feature  1202  may be comprised of any material and a combination of any number of materials. 
     Although discussed above as being adhered to the inner surface of the enclosure of the battery can  1200  at or near the weld seam  1204 , the backing feature  1202  may be located near the weld seam through other methods. For example,  FIG. 12B  is a cross-section view of a battery can  1206  illustrating a second embodiment of a protective backing feature  1202  along a seam  1204  of the can. In this example, the backing feature  1202  is pressure fit or squeeze fit between the walls  112  of the first portion  102  and the walls  116  of the second portion  104 . By pressure fitting the backing material  1202  into the space between the walls  112 ,  116 , the material does not need to be adhered to the surface of the enclosure to provide the protective feature of the backing. In such a case, a material that absorbs more radiation/light/heat may be selected regardless of the materials tendency to adhere to the metal surface of the battery can. In another example, the backing material  1202  may be brazed within the seam to hold the backing material in place. 
     The battery can designs described herein provide for the possibility of thinner walls of the can. In one embodiment, the wall thickness may be reduced from a typical 1 mm thickness down to 50-100 μm. However, such thin walls of the battery can may make it difficult to create and seal an electrolyte fill hole  108  once the electrolyte is introduced into the battery can enclosure. Thus,  FIGS. 13A and 13B  illustrate a cross-section view of a battery can wall of two embodiments of an electrolyte fill hole design of the can. In general, the electrolyte fill hole may be located in any wall  1302 ,  1308  of the battery can. The electrolyte fill hole of  FIG. 13A  includes a through-hole boss  1304  located in the wall  1302 . The through-hole provides a hole through which the electrolyte for the battery can may be introduced into the battery can enclosure. The boss through-hole  1304  may be created by folding in the boss to create a frustoconical shape in the wall  1302 . After filling, a plug  1306  is located in the boss through-hole  1304  and may be smashed, welded, or covered with a compound, such as epoxy, to create a seal over the hole. In some embodiments, the seal is cured to using ultraviolet curing, laser welding, infrared reactive polymer sealing, and the like. 
     In another embodiment of the electrolyte fill hole illustrated in  FIG. 13B , the electrolyte fill hole  1310  includes an indent in the surface of the can wall  1308 . To seal the indent  1310 , an external plate  1312  or disc may be placed into the indent and wielded or otherwise sealed into place. In one embodiment, the seal plate  1312  may be flush with the outer surface of the can wall  1308 . The sealing process of the seal plate  1312  may be similar to the methods described above with relation to  FIG. 13A . 
     Other features of the battery can  100  design are also contemplated. In one embodiment, the battery stack  302  may be glued or otherwise adhered to the large surface  110  of the first portion  102 . In general, however, the battery stack  302  may be adhered to any surface of the enclosure of the battery can  100 . Adhering the battery stack  302  to the battery can  100  may allow for less shifting of the battery stack internal to the cell under dynamic loads, minimizing damage to the battery stack and increasing the life of the battery cell. The adhesive used to adhere the battery stack  302  to the can  100  may be conductive or non-conductive. In conductive embodiments, the conductive adhesive serves as an electrical path between the anode electrodes of the battery stack  302  and the can body, thereby removing the need for one or more of the internal tabs to the battery stack. In embodiments where the stack comprises bare anodes on the outside surface of the stack, the metal-to-metal bond can be very strong. In various embodiments, such configurations can allow for less shifting of the cell stack or jelly roll internal to the cell under dynamic loads, which can reduces damage and increase the life of the cell. If the adhesive is conductive, the bond can also serve as the electrical path between the anode electrodes and the can body instead of providing a separate connector (e.g. tabs). 
     In yet another embodiment of the battery can  100  design, the can may be formed from a single piece and include a hinge portion around which the two clam shell portions of the can are folded. Once folded such that the two portion pieces meet, the pieces may be welded to form the can as described above. In this manner, the weld seam length is reduced as one edge of the weld seam includes the hinge portion of the can design. Other features and/or methods for constructing the battery cans described herein are also contemplated in conjunction with or separate from one or more of the battery can features described. 
     Additionally, although discussed herein as a battery cell design, it should be appreciated that the battery casing or battery can may be any shape and size as desired by the battery designer. For example, the battery can may be formed to fit within a prescribed area within a computing device. This form may include any number of sides, angles, and/or shapes to account for one or more other components within the computing device casing. Such battery can forms may not be possible with previous battery cell designs as the battery stack must be slid into the enclosure of the battery cell. However, because the battery stack in the can design described above is placed into the enclosure along the Z-axis instead of slid into the enclosure along the X-axis or Y-axis, the battery stack may be of a non-uniform shape to match the shape of a custom battery cell. In this manner, any shape and size of the battery cell may be created in response to the environment or device in which the battery is to be located. 
     Several advantages over conventional prismatic battery can designs can be realized through various designs and features described herein. For example, the battery can design discussed may provide an increased pressure on the battery stack located within the battery can to reduce swelling of the battery stack and prolong the life of the battery cell and improve performance. Such increases in pressure can arise from the ability to reduce a gap between the battery stack and the can body and/or adjust the thickness of the walls of the can body. Other features of the battery can to increase a pressure on the battery stack include one or more support columns within the battery can enclosure, one or more bossing features on the surfaces of the battery can, and/or one or more localized thinning features on the surfaces of the battery can. The features of the battery can design described herein provide several design choices that may strengthen the battery can and improve the overall performance and lifetime of the battery cell. 
     The battery cans, battery assemblies, and various non-limiting components and embodiments as described herein can be used with various electronic devices. Such electronic devices can be any electronic devices known in the art. For example, the device can be a telephone, such as a mobile phone, and a land-line phone, or any communication device, such as a smart phone, including, for example an iPhone®, and an electronic email sending/receiving device. The battery cans, battery assemblies, and various non-limiting components and embodiments as described herein can be used in conjunction with a display, such as a digital display, a TV monitor, an electronic-book reader, a portable web-browser (e.g., iPad®), watch and a computer monitor. The device can also be an entertainment device, including a portable DVD player, conventional DVD player, Blue-Ray disk player, video game console, music player, such as a portable music player (e.g., iPod®), etc. Devices include control devices, such as those that control the streaming of images, videos, sounds (e.g., Apple TV®), or a remote control for a separate electronic device. The device can be a part of a computer or its accessories, laptop keyboard, laptop track pad, desktop keyboard, mouse, and speaker. 
     While the present disclosure has been described with reference to various implementations, it will be understood that these implementations are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, implementations in accordance with the present disclosure have been described in the context of particular implementations. Functionality may be separated or combined in blocks differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow.

Metadata:
Filing Date: 20200313
Publication Date: 20221018
Grant Date: 20221018
Priority Date: 20150403
Inventors: PASMA, CHRISTOPHER R.
MOHAPATRA, SIDDHARTH
ANASTAS, GEORGE V.
OH, BOOKEUN
HYUNG, YOOEUP
SHIU, BRIAN K.
BALARAM, HARAN
LIU, JUNHUA
Assignee: APPLE INC
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Family ID: 55752775