Patent Publication Number: US-2015086829-A1

Title: Battery module having thermally conductive holding frame

Description:
CROSS REFERENCE 
     This application claims the benefit of co-pending U.S. Application US 53929 filed by the applicant or assignee of the present invention simultaneously with the present application, which is hereby incorporated herein. The co-pending application is temporarily identified by its Attorney docket number. This will be replaced by the corresponding USSN when available. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a battery module. 
     2. Description of Related Art 
     A battery module having a number of batteries is widely used in electronic equipment (eg, electric vehicles) as a power source. As there are many batteries in a single battery module, heat is built up in the battery module during operation and will make the battery module not work normally and safe. 
     Therefore, it is desirable to provide a battery module, to overcome or at least alleviate the above-mentioned problems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic, isometric view of a battery module, according to a first exemplary embodiment. 
         FIG. 2  is a partial exploded view of the battery module of  FIG. 1 . 
         FIG. 3  is similar to  FIG. 2 , but viewed from another angle. 
         FIG. 4  is a schematic, isometric view of the battery module of  FIG. 1  with a heat dissipating plate, top electric conductive pieces, a first and a second top electric conductive strips, bottom electric conductive pieces, a first and a second bottom electric conductive strips removed. 
         FIG. 5  is a schematic, isometric view of the battery module of  FIG. 4  with batteries removed. 
         FIG. 6  is an exploded view of the battery module of  FIG. 5 . 
         FIG. 7  is an exploded view of a top holding frame of the battery module of  FIG. 5 . 
         FIG. 8  is an exploded view of a bottom holding frame of the battery module of  FIG. 5 . 
         FIG. 9  is a schematic, isometric view of a first supporting plate of the battery module of  FIG. 5 . 
         FIG. 10  is a schematic, isometric view of a second supporting plate of the battery module of 
         FIG. 5 . 
         FIG. 11  is a partial exploded view of a battery module, according to a second exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1-4  show a battery module  100  according to a first exemplary embodiment. The battery module  100  includes a top holding frame  10 , a bottom holding frame  20 , a first supporting plate  30 , a second supporting plate  40 , two first supporting rods  50 , two second supporting rods  60 , a reinforcing plate  70 , a number of batteries  80 , a first top electric conductive strip  90 , a second top electric conductive strip  92 , a first bottom electric conductive strip  93 , a second bottom electric conductive strip  94 , a number of top electric conductive pieces  95 , a number of bottom conductive pieces  96 , and a heat dissipating plate  98 . 
     Also referring to  FIGS. 5-7 , the top holding frame  10  is substantially rectangular and is made of thermally conductive plastic. The top holding frame  10  is electrically nonconductive and elastic. The top holding frame  10  includes a first sidewall  11 , a second sidewall  12 , a third sidewall  13  and a fourth sidewall  14 . The first sidewall  11  is opposite and parallel to the second sidewall  12 . The third sidewall  13  is opposite and parallel to the fourth sidewall  14 . The first sidewall  11  and the second sidewall  12  are perpendicular to the third sidewall  13  and the fourth sidewall  14 . The first sidewall  11 , the second sidewall  12 , the third sidewall  13 , and the fourth sidewall  14  are connected end to end in sequence. The first sidewall  11  defines three first top clamping holes  110 . The three first top clamping holes  110  are arranged in a line along a direction from the fourth sidewall  14  to the third sidewall  13 . The second sidewall  12  defines three second top clamping holes  120 . The three second top clamping holes  120  are arranged in a line along a direction from the fourth sidewall  14  to the third sidewall  13 . 
     The top holding frame  10  further includes a upper surface  10   a  and a lower surface  10   b . The upper surface  10   a  is opposite and parallel to the lower surface  10   b . The top holding frame  10  defines a number of top receiving holes  15  extending through the upper surface  10   a  and the lower surface  10   b . The top receiving holes  15  are assigned into a number of first top receiving hole groups  152  and a number of second top receiving hole groups  154 . Each first top receiving hole group  152  includes a number of top receiving holes  15  arranged in a line along a direction from the third sidewall  13  to the fourth sidewall  14 . Each second top receiving hole group  154  includes a number of top receiving holes  15  arranged in a line along a direction from the third sidewall  13  to the fourth sidewall  14 . The top receiving holes  15  of the first top receiving hole groups  152  are misaligned with relative to the top receiving holes  15  of the second top receiving hole groups  154 . A number of buffering boards  16  corresponding to the top receiving holes  15  one by one are formed on the upper surface  10   a . Each buffering board  16  extends into the corresponding top receiving hole  15  and partly covers the top receiving hole  15 . In this embodiment, there are six first top receiving hole groups  152  and four second top receiving hole groups  154 . Each first top receiving hole group  152  includes eight top receiving holes  15 . Each second top receiving hole group  154  includes seven top receiving holes  15 . The line along which the top receiving holes  15  of the first top receiving hole group  152  are arranged is parallel to the line along which the top receiving holes  15  of the second top receiving hole group  154  are arranged. 
     In this embodiment, the top holding frame  10  is detachable, and includes a middle part  17 , two connecting parts  18  and two end parts  19 . The two connecting parts  18  are detachably mounted on opposite sides of the middle part  17 . The two connecting parts  18  and the middle part  17  are arranged between the two end parts  19 . The two end parts  19  are respectively detachably mounted on the two connecting parts  18 . 
     In detail, the middle part  17  includes a first side surface  172  and an opposite second side surface  174 . The middle part  17  defines two first top receiving hole groups  152 , four fixing holes  176 , fourteen first notches  177  and four clamping grooves  178 . The two top receiving hole groups  152  are located between the first side surface  172  and the second side surface  174 . The four fixing holes  176  are located between the two top receiving hole groups  152 . The four fixing holes  176  are arranged along a line from the third sidewall  13  to the fourth sidewall  14 . The fourteen first notches  177  are evenly formed at the first side surface  172  and the second side surface  174 . The four clamping grooves  178  are located at the four corners of the middle part  17 . The middle part  17  further includes four limiting hooks  179  corresponding to the four clamping grooves  178 . Each limiting hook  179  extends into the corresponding clamping groove  178 . 
     Each connecting part  18  includes a third side surface  182  and an opposite fourth side surface  184 , and defines one first top receiving hole group  152 , seven first notches  177 , seven second notches  186  and two clamping grooves  178 . The first top receiving hole group  152  is located between the third side surface  182  and the fourth side surface  184 . The seven first notches  177  are defined at the fourth side surface  184 . The seven second notches  186  are defined at the third side surface  182 . The two clamping grooves  178  are located at two opposite ends of the fourth side surface  184 . Each connecting part  18  further includes two limiting hooks  179  corresponding to the two clamping grooves  178  and two clamping hooks  188  corresponding to the two limiting hooks  179 . Each limiting hook  179  extends into the corresponding clamping groove  178 . The two clamping hooks  188  extend outwardly from two ends of the third side surface  182 . 
     Each end part  19  includes a fifth side surface  192  and an opposite sixth side surface  194 . One sixth side surface  194  of one end part  19  is an outer surface of the first sidewall  11 . One sixth side surface  194  of the other end part  19  is an outer surface of the second sidewall  12 . The end part  19  includes one first top receiving hole group  152  and seven second notches  186 . The first top receiving hole group  152  is located between the fifth side surface  192  and the sixth side surface  194 . The seven second notches  186  are defined at the fifth side surface  192 . Each end part  19  further includes two clamping hooks  188 . The two clamping hooks  188  extend outwardly from two ends of the fifth side surface  192 . 
     When assembling, first, the clamping hooks  188  at the third side surface  182  are received in the clamping grooves  178  of the middle part  17  and engage with the corresponding limiting hooks  179  to mount the two connecting parts  18  on the first side surface  172  and the second side surface  174  of the middle part  17 . Then the clamping hooks  188  at the fifth side surface  192  are received in the clamping grooves  178  at the fourth side surface  184  and engage with the corresponding limiting hooks  179  to mount the two end parts  19  on the fourth side surface  184  of the two connecting parts  18 . At this time, each second notch  186  in the connecting part  18  and the corresponding first notch  177  in the middle part  17  are aligned with each other and cooperatively form a top receiving hole  15  of the second top receiving hole group  154 , and each first notch  177  in the connecting part  18  and the corresponding second notch  186  in the end part  19  are aligned with each other and cooperatively form a top receiving hole  15  of the second top receiving hole group  154 . Because the top holding frame  10  is elastic, the clamping hooks  188  can be elastically deformed to disengage with the limiting hooks  179  to disassemble the middle part  17 , the two connecting parts  18  and the two end parts  19 . 
     In addition, the thermally conductive plastic for forming the top holding frame  10  includes a plastic material and thermally conductive material scattered in the plastic material. The plastic material is a common plastic, such as Polyamide and Polycarbonate. The thermally conductive material is evenly scattered in the plastic material to form a thermal conductive network. The thermally conductive material can be carbon, such as graphite fibers or carbon fibers, or can be particles of metallic oxide. In this embodiment, the plastic material is Polyamide, the thermally conductive material is carbon fibers. The weight ratio of the plastic material to the thermally conductive material is 50%˜70%:30%˜50%, and a sum of the weight of the plastic material and the thermally conductive material does not exceed the weight of the thermally conductive plastic. When the thermally conductive material or the weight ratio of the plastic material to the thermally conductive material varies, the thermal conductivity coefficient of the thermally conductive plastic varies accordingly. In this embodiment, the thermal conductivity coefficient of the thermally conductive plastic  300  exceeds 3 w/mk (watt/(meter*kelvin)). 
     Referring to  FIGS. 5-6 , and  8 , the structure of the bottom holding frame  20  is substantially the same as that of the top holding frame  10 . The bottom holding frame  20  is substantially rectangular and is elastic. The bottom holding frame  20  includes a first outer wall  21 , a second outer wall  22 , a third outer wall  23  and a fourth outer wall  24 . The first outer wall  21  is opposite and parallel to the second outer wall  22 . The third outer wall  23  is opposite and parallel to the fourth outer wall  24 . The first outer wall  21  and the second outer wall  22  are perpendicular to the third outer wall  23  and the fourth outer wall  24 . The first outer wall  21 , the second outer wall  22 , the third outer wall  23 , and the fourth outer wall  24  are connected end to end in sequence. The first outer wall  21  defines three first bottom clamping holes  210 . The three first bottom clamping holes  210  are arranged in a line along a direction from the fourth outer wall  24  to the third outer wall  23 . The second outer wall  22  defines three second bottom clamping holes  220 . The three second bottom clamping holes  220  are arranged in a line along a direction from the fourth outer wall  24  to the third outer wall  23 . 
     The bottom holding frame  20  further includes a top surface  20   a  and a bottom surface  20   b . The top surface  20   a  is opposite and parallel to the bottom surface  20   b . The bottom holding frame  20  defines a number of bottom receiving holes  25  extending through the top surface  20   a  and the bottom surface  20   b . The bottom receiving holes  25  are assigned to a number of first bottom receiving hole groups  252  and a number of second bottom receiving hole groups  254 . Each first bottom receiving hole group  252  includes a number of bottom receiving holes  25  arranged in a line along a direction from the third outer wall  23  to the fourth outer wall  24 . Each second bottom receiving hole group  254  includes a number of bottom receiving holes  25  arranged in a line along a direction from the third outer wall  23  to the fourth outer wall  24 . The bottom receiving holes  25  of the first bottom receiving hole group  252  are misaligned with relative to the bottom receiving holes  25  of the second bottom receiving hole group  254 . A number of supporting boards  26  corresponding to the bottom receiving holes  25  one by one are formed on the bottom surface  20   b . Each supporting board  26  extends into the corresponding bottom receiving hole  25  and partly covers the bottom receiving hole  25 . In this embodiment, there are six first bottom receiving hole groups  252  and four second bottom receiving hole groups  254 . Each first bottom receiving hole group  252  includes eight bottom receiving holes  25 . Each second bottom receiving hole group  254  includes seven bottom receiving holes  25 . The line along which the bottom receiving holes  25  of the first bottom receiving hole group  252  are arranged is parallel to the line along which the bottom receiving holes  25  of the second bottom receiving hole group  254  are arranged. 
     In this embodiment, the bottom holding frame  20  is detachable, and includes a middle portion  27 , two connecting portions  28  and two end portions  29 . The two connecting portions  28  are detachably mounted on two opposite sides of the middle portion  27 . The two connecting portions  28  and the middle portion  27  are arranged between the two end portions  29 . The two end portions  29  are respectively detachably mounted on the connecting portions  28 . 
     In detail, the middle portion  27  includes a first outer surface  272  and an opposite second outer surface  274 . The middle portion  27  defines two first bottom receiving hole groups  252 , four mounting holes  276 , fourteen first cutouts  277  and four engagement grooves  278 . The two bottom receiving hole groups  252  are located between the first outer surface  272  and the second outer surface  274 . The four mounting holes  276  are located between the two bottom receiving hole groups  252 . The four mounting holes  276  are arranged along a line from the third outer wall  23  to the fourth outer wall  24 . The fourteen first cutouts  277  are evenly formed at the first outer surface  272  and the second outer surface  274 . The four engagement grooves  278  are located at the four corners of the middle portion  27 . The middle portion  27  further includes four restricting hooks  279  corresponding to the four engagement grooves  278 . Each restricting hook  279  extends into the corresponding groove  278 . 
     Each connecting portion  28  includes a third outer surface  282  and an opposite fourth outer surface  284 , and defines one first bottom receiving hole group  252 , seven first cutouts  277 , seven second cutouts  286  and two engagement grooves  278 . The first bottom receiving hole group  252  is located between the third outer surface  282  and the fourth outer surface  284 . The seven first cutouts  277  are defined at the fourth outer surface  284 . The seven second cutouts  286  are defined at the third outer surface  282 . The two engagement grooves  278  are located at two opposite ends of the fourth outer surface  284 . Each connecting portion  28  further includes two restricting hooks  279  corresponding to the two engagement grooves  278  and two engagement hooks  288  corresponding to the two restricting hooks  279 . Each restricting hook  279  extends into the corresponding engagement groove  278 . The two engagement hooks  288  extend outwardly from two ends of the third outer surface  282 . 
     Each end portion  29  includes a fifth outer surface  292  and an opposite sixth outer surface  294 . The sixth outer surface  294  is an outer surface of the first outer wall  21  or the second outer wall  22 . The end portion  29  includes one first bottom receiving hole group  252  and seven second cutouts  286 . The first bottom receiving hole group  252  is located between the fifth outer surface  292  and the sixth outer surface  294 . The seven second cutouts  286  are defined at the fifth outer surface  292 . Each end portion  29  further includes two engagement hooks  288 . The two engagement hooks  288  extend outwardly from two ends of the fifth outer surface  292 . 
     When assembling, first, the engagement hooks  288  at the third outer surface  282  are received in the engagement grooves  278  of the middle portion  27  and engage with the corresponding restricting hooks  279  to mount the two connecting portions  28  on the first outer surface  272  and the second outer surface  274  of the middle portion  27 . Then the engagement hooks  288  at the fifth outer surface  292  are received in the engagement grooves  278  at the fourth outer surface  284  and engage with the corresponding restricting hooks  279  to mount the two end portions  29  on the fourth outer surface  284  of the two connecting portions  28 . At this time, each second cutout  286  in the connecting portion  28  and the corresponding first cutout  277  in the middle portion  27  are aligned with each other and cooperatively form a bottom receiving hole  25  of the second bottom receiving hole group  254 , and each first cutout  277  in the connecting portion  28  and the corresponding second cutout  286  in the end portion  29  are aligned with each other and cooperatively form a bottom receiving hole  25  of the second bottom receiving hole group  254 . Because the bottom holding frame  20  is elastic, the engagement hooks  288  can be elastically deformed to disengage with the restricting hooks  279  to disassemble the middle portion  27 , the two connecting portions  28  and the two end portions  29 . 
     Referring to  FIGS. 5-6 , and  9 , the first supporting plate  30  includes a first main body  32 , three first top clamping portions  34  and three first bottom clamping portions  36 . The first main body  32  is substantially a rectangular flat plate, and includes a first surface  322  and an opposite second surface  324 . The first top clamping portions  34  and the first bottom portions  36  are formed on the second surface  324 . The three first top clamping portions  34  are arranged along a line at the top end of the first main body  32  and correspond to the three first top clamping holes  110  one by one. The three first bottom clamping portions  36  are arranged along a line at the bottom end of the first main body  32  and correspond to the three first bottom clamping holes  210  one by one. Each first top clamping portion  34  includes a first top limiting block  342 , a second top limiting block  344  spaced from the first top limiting block  342 , and a first protrusion  346  protruding from the first top limiting block  342  toward the second top limiting block  344 . Each first bottom clamping portion  36  includes a first bottom limiting block  362 , a second bottom limiting block  364  spaced from the first bottom limiting block  362 , and a second protrusion  366  protruding from the second bottom limiting block  364  toward the first bottom limiting block  362 . 
     Referring to  FIGS. 5-6 , and  10 , the structure of the second supporting plate  40  is substantially the same as that of the first supporting plate  30 . The second supporting plate  40  includes a second main body  42 , three second top clamping portions  44  and second bottom clamping portions  46 . The second main body  42  is substantially a rectangular flat plate, and includes a first surface  422  and an opposite second surface  424 . The second top clamping portions  44  and the second bottom clamping portions  46  are formed on the second surface  424 . The three second top clamping portions  44  are arranged along a line at the top end of the second main body  42  and correspond to the three second top clamping holes  210  one by one. The three second bottom clamping portions  46  are arranged along a line at the bottom end of the second main body  42  and correspond to the three second bottom clamping holes  220  one by one. Each second top clamping portion  44  includes a first top restricting block  442 , a second top restricting block  444  spaced from the first top restricting block  442 , and a first projection  446  protruding from the first top restricting block  442  toward the second top restricting block  444 . Each second bottom clamping portion  46  includes a first bottom restricting block  462 , a second bottom restricting block  462  spaced from the first bottom restricting block  462 , and a second projection  466  protruding from the second bottom restricting block  462  toward the first bottom restricting block  462 . 
     Referring to  FIG. 6 , each first supporting rod  50  includes a first top end  52 , a first bottom end  54 , a first limiting piece  56 , a second limiting piece  58 , and a first outer side surface  59 . The first limiting piece  56  protrudes from the first outer side surface  59  at the first top end  52 . The second limiting piece  58  protrudes from the first outer side surface  59  at the first bottom end  54 . 
     The structure of the second supporting rod  60  is substantially the same as that of the first supporting rod  50 . Each second supporting rod  60  includes a second top end  62 , a second bottom end  64 , a third limiting piece  66 , a fourth limiting piece  68 , and a second outer side surface  69 . The third limiting piece  66  protrudes from the second outer side surface  69  at the second top end  62 . The fourth limiting piece  68  protrudes from the second outer side surface  69  at the second bottom end  64 . 
     The reinforcing plate  70  includes a body  72 , four top fixing rods  74 , and four bottom fixing rods  76 . The body  72  includes a top end  722  and an opposite bottom end  724 . The four top fixing rods  74  extend perpendicularly from the top end  722  and correspond to the four fixing holes  176 . The four bottom fixing rods  76  extend perpendicularly from the bottom end  724  and correspond to the four mounting holes  276 . 
     Referring to  FIG. 4 , each battery  80  includes a shell  82 , an anode  84 , and a cathode  86 . The anode  84  and the cathode  86  are positioned at opposite ends of the shell  82 . 
     Referring to  FIGS. 4-6 , when loading the batteries  80 , first, the top holding frame  10  and the bottom holding frame  20  are respectively integrally assembled according to the method mentioned above. Second, the cathodes  86  of the batteries  80  are inserted into the bottom receiving holes  25  and are supported by the supporting boards  26 . The first bottom ends  54  of the two first supporting rods  50  are fixedly inserted into holes (not labeled) defined in the third outer wall  23 . The first bottom ends  64  of the two second supporting rods  60  are fixedly inserted into holes (not labeled) defined in the fourth outer wall  24 . The four bottom fixing rods  76  are fixedly inserted into the four mounting holes  276 . The first and second outer side surfaces  59 ,  69  face outwardly and are opposite to the batteries  80 . Third, the top holding frame  10  is moved to above the bottom holding frame  20 . The anodes  84  of the batteries  80  are received in the top receiving holes  15  and are limited by the buffering boards  16 . The first top ends  52  of the two first supporting rods  50  are fixedly inserted into holes (not labeled) defined in the third sidewall  13 . The first top ends  62  of the two second supporting rods  60  are fixedly inserted into holes (not labeled) defined in the fourth sidewall  14 . The four top fixing rods  74  are fixedly inserted into the four fixing holes  176 . The top receiving holes  15  are aligned with the bottom receiving holes  25  one by one. The first sidewall  11  is aligned with the first outer wall  21 . The second sidewall  12  is aligned with the second outer wall  22 . The third sidewall  13  is aligned with the third outer wall  23 . The fourth sidewall  14  is aligned with the fourth outer wall  24 . Finally, the first sidewall  11  is clamped by the first top limiting blocks  342  and the second top limiting blocks  344 . The first protrusions  346  are engaged in the first top clamping holes  110 . The first outer wall  21  is clamped by the first bottom limiting blocks  362  and the second bottom limiting blocks  364 . The second protrusions  366  are engaged in the first bottom clamping holes  210 . The second sidewall  12  is clamped by the first top restricting blocks  442  and the second top restricting blocks  444 . The first projections  446  are engaged in the second top clamping holes  210 . The second outer wall  22  is clamped by the first bottom restricting blocks  462  and the second bottom restricting blocks  464 . The second projections  466  are engaged in the second bottom clamping holes  220 . In this way, the top holding frame  10  and the bottom holding frame  20  are fixedly connected together and are spaced from each other. In other embodiments, the first supporting rods  50 , the second supporting rods  60 , and the reinforcing plate  70  can be removed, and the top holding frame  10  is connected to the bottom holding frame  20  only by the first supporting plate  30  and the second supporting plate  40 . 
     Referring to FIGS.  2  and  5 - 6 , the first top electric conductive strip  90 , the second top electric conductive strip  92 , the first bottom electric conductive strip  93 , the second bottom electric conductive strip  94 , the top electric conductive pieces  95 , and the bottom electric conductive pieces  96  are made of copper. 
     The first top electric conductive strip  90  is first supported on the two first limiting pieces  56 , and is then adhered to the two first outer side surfaces  59 . The first top electric conductive strip  90  is located at the first top end  52 . A length of the first top electric conductive strip  90  is substantially equal to that of the third sidewall  13 . The second top electric conductive strip  92  is first supported on the two third limiting pieces  66 , and is then adhered to the two second outer side surfaces  69 . The second top electric conductive strip  92  is located at the second top end  62 . A length of the second top electric conductive strip  92  is substantially equal to that of the fourth sidewall  14 . The first bottom electric conductive strip  93  first contacts the two second limiting pieces  58 , and is then adhered to the two first outer side surfaces  59 . The first bottom electric conductive strip  93  is located at the first bottom end  54 . A length of the first bottom electric conductive strip  93  is substantially equal to that of the third outer wall  23 . The second bottom electric conductive strip  94  first contacts the two second limiting pieces  68 , and is then adhered to the two second outer side surfaces  69 . The second bottom electric conductive strip  94  is located at the second bottom end  64 . A length of the second bottom electric conductive strip  94  is substantially equal to that of the fourth outer wall  24 . 
     The anodes  84  received in the same first top receiving hole group  152  are connected in parallel through the top electric conductive pieces  95 . The anodes  84  received in the same second top receiving hole group  154  are connected in parallel through the top electric conductive pieces  95 . The anodes  84  adjacent to the third sidewall  13  are connected to the first top electric conductive strip  90  through the top electric conductive pieces  95 . The anodes  84  adjacent to the fourth sidewall  14  are connected to the second top electric conductive strip  92  through the top electric conductive pieces  95 . The cathodes  86  received in the same first bottom receiving hole group  252  are connected in parallel through the bottom electric conductive pieces  96 . The cathodes  86  received in the same second bottom receiving hole group  254  are connected in parallel through the bottom electric conductive pieces  96 . The cathodes  86  adjacent to the third outer wall  23  are connected to the first bottom electric conductive strip  93  through the bottom electric conductive pieces  96 . The cathodes  86  adjacent to the fourth outer wall  24  are connected to the second bottom electric conductive strip  94  through the bottom electric conductive pieces  96 . 
     Referring to  FIGS. 1-2  and  6 , the heat dissipating plate  98  is adhered to the upper surface  10   a  of the top holding frame  10 . The heat dissipating plate  98  is made of thermally conductive silicon rubber. 
     When working, the anodes  84  of the batteries  80  produce heat. As the anodes  84  are received in the top receiving holes  15  and are in contact with the top holding frame  10 , and the top holding frame  10  is made of thermally conductive plastic, the top holding frame  10  transfers the heat from the anodes  84  to the heat dissipating plate  98  for heat dissipating, and the heat will not build up in the battery module  100  to make sure the battery module  100  can work normally and safe. As the top holding frame  10  can be used to transfer heat, other heat transferring mechanism can be saved. Thus, the battery module  100  is simplified in structure and small in volume. 
     Referring to  FIG. 11 , a battery module  200  according to a second embodiment is shown. The battery module  200  is similar to the battery module  100  except that a bottom holding frame  20  of the battery module  200  is also made of thermally conductive plastic and the battery module  200  further includes a heat dissipating panel  99  adhered to the bottom surface  20   b  of the bottom holding frame  20 . The heat dissipating panel  99  is made of thermally conductive silicon rubber. 
     In the battery module  200 , heat generated from the cathodes  86  can be dissipated by the heat dissipating panel  99 . Thus, the heat dissipating efficiency of the battery module  200  is further increased. 
     Even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.