Patent Publication Number: US-2015086830-A1

Title: Battery module having thermally conductive holding frame

Description:
CROSS REFERENCE 
     This application claims the benefit of co-pending U.S. Application filed by the applicant or assignee of the present invention simultaneously with the present application: U.S. Ser. No. 53,928, which is hereby incorporated herein. The co-pending application is temporarily identified by its 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 
     Battery modules including a number of batteries are widely used as a power source to provide power to, for example, electric vehicles. As there are many batteries in a single battery module, heat is generated in the battery module during operation and can render the battery module unreliable and unsafe. 
     Therefore, it is desirable to provide a battery module which can overcome the shortcomings mentioned above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is a schematic, isometric view of a battery module according to a first embodiment of the present disclosure. 
         FIG. 2  is a partially 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  without a heat dissipating plate, top electric conductive pieces, a first and a second top electric conductive strips, bottom electric conductive pieces, and a first and a second bottom electric conductive strips. 
         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 partially exploded view of a battery module according to a second embodiment of the present disclosure. 
         FIG. 12  is a schematic view showing components of a thermally conductive plastic according to a third embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 to 4 , a battery module  100  according to a first embodiment of the present disclosure is shown. 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 to 7 , the top holding frame  10  is substantially rectangular and is made of thermally conductive plastic. The top holding frame  10  is electrically non-conductive 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 with each other. 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 top surface  10   a  and a bottom surface  10   b.  The top surface  10   a  is opposite and parallel to the bottom surface  10   b.  The top holding frame  10  defines a number of top receiving holes  15  extending through the top surface  10   a  and the bottom surface  10   b.  The top receiving holes  15  include 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 offset relative to the top receiving holes  15  of the second top receiving hole groups  154 . A number of buffering boards  16  corresponding one-to-one to the top receiving holes  15  are formed on the top surface  10   a.  Each buffering board  16  extends into a 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 two 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 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 a 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 are defined at the fourth side surface  184 . The seven second notches are defined at the third side surface  182 . The two clamping grooves  178  are located at 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 a 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 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 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 elastically deform to disengage from the limiting hooks  179  to disassemble the middle part  17 , the two connecting parts  18 , and the two end parts  19 . 
     Referring to  FIGS. 5 ,  6 , and  8 , the structure of the bottom holding frame  20  is substantially the same the structure 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 sidewall  21 , a second sidewall  22 , a third sidewall  23 , and a fourth sidewall  24 . The first sidewall  21  is opposite and parallel to the second sidewall  22 . The third sidewall  23  is opposite and parallel to the fourth sidewall  24 . The first sidewall  21  and the second sidewall  22  are perpendicular to the third sidewall  23  and the fourth sidewall  24 . The first sidewall  21 , the second sidewall  22 , the third sidewall  23 , and the fourth sidewall  24  are connected end to end with each other. The first sidewall  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 sidewall  24  to the third sidewall  23 . The second sidewall  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 sidewall  24  to the third sidewall  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  include 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 sidewall  23  to the fourth sidewall  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 sidewall  23  to the fourth sidewall  24 . The bottom receiving holes  25  of the first bottom receiving hole group  252  are offset relative to the bottom receiving holes  25  of the second bottom receiving hole group  254 . A number of buffering boards  26  corresponding one-to-one to the bottom receiving holes  25  are formed on the bottom surface  20   b.  Each buffering board  26  extends into a 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 part  27 , two connecting parts  28 , and two end parts  29 . The two connecting parts  28  are detachably mounted on opposite sides of the middle part  27 . The two connecting parts  28  and the middle part  27  are arranged between the two end parts  29 . The two end parts  29  are detachably mounted on the connecting parts  28 . 
     In detail, the middle part  27  includes a first side surface  272  and an opposite second side surface  274 . The middle part  27  defines two first bottom receiving hole groups  252 , four fixing holes  276 , fourteen first notches  277 , and four clamping grooves  278 . The two bottom receiving hole groups  252  are located between the first side surface  272  and the second side surface  274 . The four fixing holes  276  are located between the two bottom receiving hole groups  252 . The four fixing holes  276  are arranged along a line from the third sidewall  23  to the fourth sidewall  24 . The fourteen first notches  277  are evenly formed at the first side surface  272  and the second side surface  274 . The four clamping grooves  278  are located at the four corners of the middle part  27 . The middle part  27  further includes four limiting hooks  279  corresponding to the four clamping grooves  278 . Each limiting hook  279  extends into a groove  278 . 
     Each connecting part  28  includes a third side surface  282  and an opposite fourth side surface  284 , and defines one first bottom receiving hole group  252 , seven first notches  277 , seven second notches  286  and two clamping grooves  278 . The first bottom receiving hole group  252  is located between the third side surface  282  and the fourth side surface  284 . The seven first notches  277  are defined at the fourth side surface  284 . The seven second notches  286  are defined at the third side surface  282 . The two clamping grooves  278  are located at opposite ends of the fourth side surface  284 . Each connecting part  28  further includes two limiting hooks  279  corresponding to the two clamping grooves  278  and two clamping hooks  288  corresponding to the two limiting hooks  279 . Each limiting hook  279  extends into a clamping groove  278 . The two clamping hooks  288  extend outwardly from two ends of the third side surface  282 . 
     Each end part  29  includes a fifth side surface  292  and an opposite sixth side surface  294 . The sixth side surface  294  is an outer surface of the first sidewall  21  or of the second sidewall  22 . The end part  29  includes one first bottom receiving hole group  252  and seven second notches  286 . The first bottom receiving hole group  252  is located between the fifth side surface  292  and the sixth side surface  294 . The seven second notches  286  are defined at the fifth side surface  292 . Each end part  29  further includes two clamping hooks  288 . The two clamping hooks  288  extend outwardly from two ends of the fifth side surface  292 . 
     When assembling, first, the clamping hooks  288  at the third side surface  282  are received in the clamping grooves  278  of the middle part  27  and engage with the limiting hooks  279  to mount the two connecting parts  28  on the first side surface  272  and the second side surface  274  of the middle part  27 . Then the clamping hooks  288  at the fifth side surface  292  are received in the clamping grooves  278  at the fourth side surface  284  and engage with the limiting hooks  279  to mount the two end parts  29  on the fourth side surface  284  of the two connecting parts  28 . At this time, each second notch  286  in the connecting part  28  and the corresponding first notch  277  in the middle part  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 notch  277  in the connecting part  28  and the corresponding second notch  286  in the end part  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 clamping hooks  288  can elastically deform to disengage from the limiting hooks  279  to disassemble the middle part  27 , the two connecting parts  28 , and the two end parts  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 one-to-one to the three first top clamping holes  110 . The three first bottom clamping portions  36  are arranged along a line at the bottom end of the first main body  32  and correspond one-to-one to the three first bottom clamping holes  210 . 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  projecting from the first top limiting block  342  and facing 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  projecting from the second bottom limiting block  364  and facing 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 the structure of the first supporting plate  30 . The second supporting plate  40  includes a first main body  42 , three first top clamping portions  44  and three first bottom portions  46 . The first main body  42  is substantially a rectangular flat plate, and includes a first surface  422  and an opposite second surface  424 . The first top clamping portions  44  and the first bottom portions  46  are formed on the second surface  424 . The three first top clamping portions  44  are arranged along a line at the top end of the first main body  42  and correspond one-to-one to the three second top clamping holes  210 . The three first bottom clamping portions  46  are arranged along a line at the bottom end of the first main body  42  and correspond one-to-one to the three second bottom clamping holes  220 . Each first top clamping portion  44  includes a first top limiting block  442 , a second top limiting block  444  spaced from the first top limiting block  442 , and a first protrusion  446  projecting from the first top limiting block  442  and facing the second top limiting block  444 . Each first bottom clamping portion  46  includes a first bottom limiting block  462 , a second bottom limiting block  464  spaced from the first bottom limiting block  462 , and a second protrusion  466  projecting from the second bottom limiting block  464  and facing the first bottom limiting 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  projects from the first outer side surface  59  at the first top end  52 . The second limiting piece  58  projects 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 the structure of the first supporting rod  50 . Each second supporting rod  60  includes a first top end  62 , a first bottom end  64 , a first limiting piece  66 , a second limiting piece  68 , and a first outer side surface  69 . The first limiting piece  66  projects from the first outer side surface  69  at the first top end  62 . The second limiting piece  68  projects from the first outer side surface  69  at the first 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 fixing 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 to 6 , when loading the batteries  80 , first, the top holding frame  10  and the bottom holding frame  20  are 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 buffering 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 sidewall  23 . The first bottom ends  64  of the two second supporting rods  60  are fixedly inserted into holes (not labeled) defined in the fourth sidewall  23 . The four bottom fixing rods  76  are fixedly inserted into the four fixing holes  276 . The first outer side surfaces  59 ,  69  face outward and are opposite to the batteries  80 . Third, the top holding frame  10  is moved 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 each aligned with a bottom receiving hole  25 . The first sidewalls  11 ,  21  are aligned with each other. The second sidewalls  12 ,  22  are aligned with each other. The third sidewalls  13 ,  23  are aligned with each other. The fourth sidewalls  14 ,  24  are aligned with each other. 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 with the first top clamping holes  110 . The first sidewall  21  is clamped by the first bottom limiting blocks  362  and the second bottom limiting blocks  364 . The second protrusions  366  are engaged with the first bottom clamping holes  210 . The second sidewall  12  is clamped by the first top limiting blocks  442  and the second top limiting blocks  444 . The first protrusions  446  are engaged with the second top clamping holes  210 . The second sidewall  22  is clamped by the first bottom limiting blocks  462  and the second bottom limiting blocks  464 . The second protrusions  466  are engaged with 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 another embodiment, the first supporting rods  50 , the second supporting rods  60 , and the reinforcing plate  70  can be removed, and then the top holding frame  10  would be connected to the bottom holding frame only by the first supporting plate  30  and the second supporting plate  40 . 
     Referring to  FIGS. 2 ,  5 , and  6 , the first top electric conductive strip  90 , the second 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 supported by the two first limiting pieces  56  and is 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 equal a length of the third sidewall  13 . The second top electric conductive strip  92  is supported by the two first limiting pieces  66  and is adhered to the two first outer side surfaces  69 . The second top electric conductive strip  92  is located at the first top end  62 . A length of the second top electric conductive strip  92  is equal a length of the fourth sidewall  14 . The first bottom electric conductive strip  93  is supported by the two second limiting pieces  58  and is 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 equal a length of the third sidewall  23 . The second bottom electric conductive strip  94  is supported by the two second limiting pieces  68  and is adhered to the two first outer side surfaces  69 . The second bottom electric conductive strip  94  is located at the first bottom end  64 . A length of the second bottom electric conductive strip  94  is equal a length of the fourth sidewall  24 . 
     The anodes  84  received in the same first top receiving hole group  152  are connected in parallel by the top electric conductive pieces  95 . The anodes  84  received in the same second top receiving hole group  154  are connected in parallel by the top electric conductive pieces  95 . The anode  84  adjacent to the third sidewall  13  is connected to the first top electric conductive strip  90  by the top electric conductive piece  95 . The anode  84  adjacent to the fourth sidewall  14  is connected to the second top electric conductive strip  92  by the top electric conductive piece  95 . The cathodes  86  received in the same first bottom receiving hole group  252  are connected in parallel by the bottom electric conductive pieces  96 . The cathodes  86  received in the same second bottom receiving hole group  254  are connected in parallel by the bottom electric conductive pieces  96 . The cathode  86  adjacent to the third sidewall  23  is connected to the first bottom electric conductive strip  93  by the bottom electric conductive piece  96 . The cathode  86  adjacent to the fourth sidewall  24  is connected to the second bottom electric conductive strip  94  by the bottom electric conductive piece  96 . 
     Referring to  FIGS. 1 ,  2  and  6 , the heat dissipating plate  98  is adhered to the top 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. The anodes  84  are received in the top receiving holes  15  and are in contact with the top holding frame  10 . Because 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 dissipation. The heat will not remain in the battery module  100 , thus ensuring normal and safe working of the battery module  100 . As it is the top holding frame  10  which is used to transfer heat, no other heat transferring mechanism is required. Thus, the battery module  100  is simplified in structure and reduced in volume. 
     Referring to  FIG. 11 , a battery module  200  according to a second embodiment of the present disclosure is disclosed. 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 plate  99  adhered to the bottom surface  20   b  of the bottom holding frame  20 . The heat dissipating plate  99  is made of thermally conductive silicon rubber. 
     In the battery module  200 , heat generated by the cathodes  86  is dissipated by the heat dissipating plate  99 . Thus, the heat dissipating efficiency of the battery module  200  is further increased. 
     Referring to  FIG. 12 , a thermally conductive plastic  300  for forming the top holding frame  10  and the bottom holding frame  20  is disclosed. The thermally conductive plastic  300  includes a plastic material  301  and thermally conductive material  302  dispersed in the plastic material  301 . The plastic material  301  is a common plastic, such as polyamide or polycarbonate. The thermally conductive material  302  is evenly dispersed in the plastic material  301  to form a thermally conductive network. The thermally conductive material  302  can be carbon, such as graphite fibers or carbon fibers, or can be particles of metallic oxide. In this embodiment, the plastic material  301  is polyamide, and the thermally conductive material  302  is carbon fibers. The weight ratio of the plastic material  301  to the thermally conductive material  302  is 50%-70%: 30%-50%, and a sum of the weight of the plastic material  301  and the thermally conductive material  302  does not exceed the weight of the thermally conductive plastic  300 . When the thermally conductive material  302  or the weight ratio of the plastic material  301  to the thermally conductive material  302  varies, the thermal conductivity coefficient of the thermally conductive plastic  300  also varies. In this embodiment, the thermal conductivity coefficient of the thermally conductive plastic  300  exceeds 3 w/mk (watt/(meter*kelvin)). 
     It will be understood that the above particular embodiments are shown and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiments thereof without departing from the scope of the disclosure. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure.