Patent Publication Number: US-2023155239-A1

Title: Cell fixing apparatus and battery module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Chinese Patent Application No. 202122837840.1, filed on Nov. 18, 2021, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The embodiments relate to the field of electric storage apparatuses, a cell fixing apparatus, and a battery module. 
     BACKGROUND 
     To resolve a problem of severe intermittence of large-scale photovoltaic power generation and wind power generation, with rapid decrease of battery costs, battery energy storage has been developed rapidly in both a power generation side and a power consumption side, and an installed capacity is also significantly increased due to characteristics of the battery energy storage, such as flexible application, high reliability and controllability, and high energy density. 
     An existing battery module may have high volumetric energy density and a compact module. In addition, a cell in the battery module needs to run for a long time, and the cell stores and releases electric energy through electrochemical reaction. Relative positions of electrode plates in the cell have significant impact on the electrochemical reaction of the cell. However, with the use of the cell, the cell is prone to expansion and deformation, and the electrode plates in the cell are relatively far away, degrading performance of the cell. 
     SUMMARY 
     The embodiments may provide a cell fixing apparatus and a battery module, so as to facilitate stable operation of the cell. 
     A first aspect may provide a cell fixing apparatus, including a first shell element, a second shell element, and a plurality of pressure-adding beams. The first shell element and the second shell element are relatively fixedly connected, the first shell element and the second shell element are disposed at intervals in a first direction, so that an accommodating cavity is provided between the first shell element and the second shell element, and the accommodating cavity is configured to accommodate the cell. A plurality of connection areas may be disposed at intervals along a second direction on a surface of the first shell element that is away from the second shell element, the second direction is perpendicular to the first direction, and the pressure-adding beam may be fixed in a corresponding connection area. The plurality of pressure-adding beams may include a first-type beam and a second-type beam. A size of the first-type beam in the first direction is greater than that of the second-type beam. 
     The cell fixing apparatus fixes relative positions of a plurality of cells in the first direction by using the first shell element and the second shell element, and the pressure-adding beam may be selectively disposed in the corresponding connection area. The cell is prone to deformation during a life cycle of the cell. A deformed cell exerts pressure on the pressure-adding beam, and in turn, the pressure-adding beam exerts a reaction force on the cell to limit deformation of the cell, so that the cell can maintain its shape to operate more stably. A type of the pressure-adding beam is selected based on a characteristic of the cell, the first-type beam or the second-type beam is selected to be mounted in a corresponding connection area on the first shell element, so as to further improve flexibility of the first shell element and the second shell element for controlling the deformation of the cell. In other words, the first shell element and the second shell element can more flexibly cope with the deformation of the cell. The first-type beam may provide a greater reaction force in a local area than the second-type beam, so as to limit the deformation of the cell. 
     According to the first aspect, in a possible implementation, the plurality of pressure-adding beams may include a third-type beam and a fourth-type beam. A size of the third type in the second direction is greater than that of the fourth-type beam. 
     In this possible implementation, the cell fixing apparatus may select, based on the characteristic of the cell, the third-type beam or the fourth-type beam to be mounted in a corresponding connection area on the first shell element, so as to further improve flexibility of the first shell element and the second shell element for controlling the deformation of the cell. In other words, the first shell element and the second shell element can more flexibly cope with the deformation of the cell. The third-type beam may provide a reaction force in a larger area in comparison with the fourth-type beam, so as to limit the deformation of the cell. 
     According to the first aspect, in a possible implementation, the cell fixing apparatus further includes a plurality of bracings, the first shell element and the second shell element are connected by using a plurality of bracings, the bracing extends along the first direction, and a surface of the bracing has an insulation layer. 
     In this possible implementation, in the cell fixing apparatus, insulation of the surface of the bracing can increase a creepage distance between cells. 
     According to the first aspect, in a possible implementation, the plurality of bracings may include a first-type bracing and a second-type bracing. A size of the first-type bracing in the second direction and/or a third direction is greater than that of the second-type bracing, and the third direction is perpendicular to the first direction and the second direction. 
     In this possible implementation, on a cross section perpendicular to the first direction, a cross-sectional area of the first-type bracing is larger than a cross-sectional area of the second-type bracing, so that the first-type bracing provides greater tension in the first direction in comparison with the second-type bracing, and provides a greater reaction force for the cell in the accommodating cavity, so as to limit the deformation of the cell. 
     According to the first aspect, in a possible implementation, the cell fixing apparatus further includes a third shell element and a fourth shell element, the third shell element and the fourth shell element are disposed at intervals in a third direction, the third direction is perpendicular to the first direction and the second direction, and the accommodating cavity is located between the third shell element and the fourth shell element. 
     In this possible implementation, in the cell fixing apparatus, the third shell element and the fourth shell element may cover two ends of the cell in the third direction, so as to provide more comprehensive protection for the cell. 
     According to the first aspect, in a possible implementation, the cell fixing apparatus further includes a first busbar, and the first busbar is disposed on a surface of the third shell element that is close to the fourth shell element. The first busbar is configured to correspond to a tab of the cell. 
     In this possible implementation, the cell whose tab faces the third shell element is disposed in the cell fixing apparatus, and the first busbar cooperates with the cell to electrically connect the plurality of cells. 
     According to the first aspect, in a possible implementation, a first insulation part is disposed between the first busbar and the third shell element, and the first insulation part insulates and isolates the first busbar and the third shell element. 
     In this possible implementation, in the cell fixing apparatus, insulation performance of the third shell element can be increased by using the first insulation part, so as to improve safety of the cell fixing apparatus. 
     According to the first aspect, in a possible implementation, the first insulation part includes an epoxy resin board. 
     In this possible implementation, the epoxy resin board is low in costs, easy to manufacture, and excellent in insulation performance 
     According to the first aspect, in a possible implementation, the cell fixing apparatus further includes a second busbar, and the second busbar is disposed on a surface of the fourth shell element that is close to the third shell element. The second busbar is configured to correspond to the tab of the cell. 
     In this possible implementation, two cells whose tabs respectively face the third shell element and the fourth shell element are disposed in the cell fixing apparatus, and the first busbar and the second busbar cooperate with the cell to electrically connect the plurality of cells. 
     According to the first aspect, in a possible implementation, the cell fixing apparatus further includes a fifth shell element and a sixth shell element, the fifth shell element and the sixth shell element are disposed at intervals in the second direction, and the accommodating cavity is located between the fifth shell element and the sixth shell element. The fifth shell element is connected to the first shell element and the second shell element, and the sixth shell element is connected to the first shell element and the second shell element. 
     In this possible implementation, in the cell fixing apparatus, the fifth shell element and the sixth shell element may cover two ends of the cell in the second direction, so as to provide more comprehensive protection for the cell. 
     According to the first aspect, in a possible implementation, a first insulation film is disposed on a surface of the fifth shell element that is close to the sixth shell element, and a second insulation film is disposed on a surface of the sixth shell element that is close to the fifth shell element. 
     In this possible implementation, in the cell fixing apparatus, insulation performance of the fifth shell element and the sixth shell element can be increased by using the first insulation film and the second insulation film, so as to improve safety of the cell fixing apparatus. 
     A second aspect may provide a battery module, including a cell group and the cell fixing apparatus provided in the first aspect. The cell group includes a plurality of cells stacked along the first direction, and the cell group is disposed in the accommodating cavity of the cell fixing apparatus. 
     In this possible implementation, the cell fixing apparatus in the battery module provides a uniform reaction force for the cell to limit deformation of the cell, so that the cell can operate stably. In addition, reasonable distribution of pressure-adding beams enables the cell to maintain a stable shape in an entire life cycle through a reaction force of the pressure-adding beam. 
     According to the second aspect, in a possible implementation, the cell includes a first type cell or a second type cell. When the first type cell is accommodated in the accommodating cavity, the plurality of pressure-adding beams may be in a first distribution on a surface of the first shell element that is away from the second shell element. When the second type cell is accommodated in the accommodating cavity, the plurality of pressure-adding beams may be in a second distribution on a surface of the first shell element that is far away from the second shell element. A position of at least one of the pressure-adding beams varies in the first distribution and the second distribution. 
     In this possible implementation, a position for mounting the pressure-adding beam is selected based on a type of the cell. When the cell fixing apparatus accommodates the first type cell, the plurality of pressure-adding beams may be selected to be in the first distribution to adapt to a position at which the first type cell is prone to expansion. When the cell fixing apparatus accommodates the second type cell, the plurality of pressure-adding beams may be selected to be in the second distribution to adapt to a position at which the second type cell is prone to expansion. 
     According to the second aspect, in a possible implementation, a quantity of cell groups is at least two, and the at least two cell groups are disposed in parallel along the second direction. 
     In this possible implementation, the cell fixing apparatus can be additionally provided with more cells for a same size in the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exploded view of a battery module according to an implementation; 
         FIG.  2    is a schematic diagram of a structure of a first shell element and a second shell element holding a cell group according to an implementation; and 
         FIG.  3    is an exploded view of a battery module according to an implementation, where a first shell element and a first insulation part are obtained by decomposing the battery module. 
     
    
    
     The following embodiments are described with reference to the foregoing accompanying drawings. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Implementations are described below in the embodiments, and other advantages and effects may be readily understood by a person skilled in the art from content in the embodiments. Although the description is provided with reference to the embodiments, this does not mean that features are limited to this implementation. On the contrary, a purpose of the description is to cover another option or modification that may be derived according to the embodiments. For an in-depth understanding, the following description includes many details. The embodiments may be alternatively implemented without using these details. In addition, to avoid confusion or obfuscation, some details are omitted from the description. It should be noted that the embodiments may be mutually combined in the case of no conflict. 
     The following terms “first”, “second”, and the like are merely used for description, and shall not be understood as an indication or implication of relative importance or implicit indication of a quantity of indicated features. Therefore, a feature limited by “first”, “second”, or the like may explicitly indicate or implicitly include one or more of the features. In the descriptions, unless otherwise stated, “a plurality of” means two or more than two. Orientation terms such as “up”, “down”, “left” and “right” are defined with respect to orientations of components that are schematically placed in accompanying drawings, and it should be understood that these directional terms are relative concepts, are used for relative description and clarification, and may vary accordingly based on a change in the orientation in which the components are disposed in the accompanying drawings. 
     If used, unless otherwise expressly specified and limited, the term “connection” should be understood in a broad sense, for example, “connection” may be a fixed connection, may be a detachable connection, or may be an integral connection; or “connection” may be a direct connection or an indirect connection by using an intermediate medium. As used herein, term “and/or” includes any and all combinations of one or more related listed items. 
     When the following embodiments are described in detail with reference to schematic diagrams, for ease of description, a diagram indicating a partial structure of a device is not partially enlarged in accordance with a general scale. In addition, the schematic diagrams are merely examples, and should not limit a scope of the embodiments. 
     To make the objectives, solutions, and advantages clearer, the following further describes the embodiments in detail with reference to the accompanying drawings. 
       FIG.  1    is an exploded view of a battery module according to an implementation. 
     As shown in  FIG.  1   , the battery module includes a cell group and a cell fixing apparatus  010 , and the cell group is fixed in the cell fixing apparatus  010 . When the battery module is electrically connected to an external device, the battery module supplies electric energy to the external device by using the cell group. 
     The cell fixing apparatus  010  includes a first shell element  110  and a second shell element  120  that are disposed at intervals along a first direction X. The first shell element  110  and the second shell element  120  are connected by using a plurality of bracings  170 , and the bracings  170  may maintain relative positions of the first shell element  110  and the second shell element  120 . An accommodating cavity is provided between the first shell element  110  and the second shell element  120 , and four cell groups are accommodated in the accommodating cavity, and pressure is exerted on the cell groups by using the first shell element  110  and the second shell element  120 . The cell group includes four cells  030  stacked along the first direction X, the four cell groups are disposed in parallel along a second direction Y, and the second direction Y is perpendicular to the first direction X. In other words, sixteen cells  030  are mounted between the first shell element  110  and the second shell element  120 . The cell  030  includes a package shell and an electrode plate (not shown in the figure), and electrode plates of the cell  030  are stacked along the first direction X. The electrode plate may include a positive electrode plate and a negative electrode plate, and the positive electrode plate and the negative electrode plate may be stacked crosswise along the first direction X, so as to implement discharging of the cell  030  through an electrochemical reaction. Deformation of the cell  030  exerts pressure on the first shell element  110  and the second shell element  120 , and correspondingly, the first shell element  110  and the second shell element  120  exert a reaction force in the first direction X on the cell  030 , so as to maintain a shape of the cell  030 . When the shape of the cell  030  remains stable, two adjacent electrode plates in the cell  030  can be maintained at a relatively small spacing, so that the cell  030  can operate stably. 
     Both the first shell element  110  and the second shell element  120  are sheet metal parts, so that manufacturing costs of the first shell element  110  and the second shell element  120  are reduced, and the first shell element  110  and the second shell element  120  can have relatively high overall strength. 
       FIG.  2    is a schematic diagram of a structure of a first shell element  110  and a second shell element  120  holding a cell group according to an implementation. 
     As shown in  FIG.  1    and  FIG.  2   , cell fixing apparatus  010  further includes a plurality of pressure-adding beams  180 , and the pressure-adding beams  180  may be fixed on a surface of a first shell element  110  that is away from a second shell element  120 . When applied to different types of cells  030 , a same cell fixing apparatus  010  may be provided with the pressure-adding beam  180  based on an actual requirement of the cell  030  of the type. However, even if a same type of cell  030  is used to cope with different batches or different elapsed years of the cell  030 , a corresponding pressure-adding beam  180  may be mounted at a position of the cell  030  that requires a greater reaction force to limit deformation, so that the pressure-adding beam  180  can be suitably distributed in each cell  030  in the cell fixing apparatus  010 . In addition, the pressure-adding beam  180  has relatively high strength and is not easily deformed and can exert a relatively great reaction force on the cell  030 . When the cell  030  tends to expand as the use time extends, the pressure-adding beam  180  can limit such expansion, so that the electrode plates in the cell  030  are maintained at the relatively small spacing, thereby maintaining stable operation of the cell  030 . 
     When a first type cell is selected as the cell  030  in the cell group, the plurality of pressure-adding beams  180  may be in a first distribution on a surface of the first shell element  110  that is away from the second shell element  120 . For example, a center of the first type cell is prone to bulging, and the first distribution means that the pressure-adding beam  180  is disposed correspondingly at a position in the first shell element  110  that corresponds to the center of the first type cell. When a second type cell is selected as the cell  030  in the cell group, the plurality of pressure-adding beams  180  may be in a second distribution on the surface of the first shell element  110  that is away from the second shell element  120 . For example, an edge of the second type cell is prone to bulging, and the second distribution means that the pressure-adding beam  180  is disposed correspondingly at a position in the first shell element  110  that corresponds to the edge of the second type cell. 
     A plurality of connection areas may be provided on the surface of the first shell element  110  that is away from the second shell element  120 , and a connection area is used for mounting the pressure-adding beam  180 . The first shell element  110  may be provided with a connector  111  at a position of the connection area, and the connector  111  may be configured to connect the pressure-adding beam  180 . The connector  111  of each connection area may be a plurality of protrusions disposed at intervals along a third direction Z, and a protrusion forms a solder joint. The third direction Z is perpendicular to a first direction X and a second direction Y. The protrusion and the pressure-adding beam  180  are welded to fix the pressure-adding beam  180  on the first shell element  110 . 
     The plurality of pressure-adding beams  180  may include a variety of types. The plurality of pressure-adding beams  180  may include a first-type beam and a second-type beam, and a size of the first-type beam in the first direction X may be greater than a size of the second-type beam in the first direction X. When the first-type beam and the second-type beam are subjected to same pressure from the cell  030  in the first direction X, deformation of the first-type beam may be less obvious than that of the second-type beam. Similarly, when the first-type beam and the second-type beam have same deformation, the first-type beam can exert a greater reaction force on the cell  030  in the first direction X in comparison with the second-type beam. 
     The plurality of pressure-adding beams  180  may further include a third-type beam and a fourth-type beam, and a size of the third-type beam in the second direction Y is greater than a size of the fourth-type beam in the second direction Y. In other words, when the third-type beam and the fourth-type beam are subjected to same pressure from the cell  030  in the first direction X, the third-type beam can exert a reaction force on the cell  030  in a larger coverage area in comparison with the fourth-type beam. In addition, the third-type beam is relatively less prone to deformation, and when a same quantity of third-type beams or fourth-type beams are disposed on the first shell element  110 , the third-type beam can exert a greater reaction force on the cell  030 . 
     The first-type beam may also belong to the third-type beam, that is, sizes of some first-type beams in the second direction Y may be greater than sizes of some second-type beams. The first-type beam may also belong to the fourth-type beam, that is, sizes of some first-type beams in the second direction Y are smaller than sizes of some second-type beams. 
     A bracing  170  may use a strip sheet metal part, so that the bracing  170  has relatively high strength and relatively low manufacturing costs. A tab  031  of the cell  030  extends out of a package shell of the cell  030  along the third direction Z, and a distance between the tab  031  of the cell  030  and the bracing  170  is relatively close. An insulation layer is disposed outside the bracing  170 , so as to effectively increase a creepage distance between the cells  030 . 
     The first shell element  110  is provided with a first locating slot  113  at two opposite ends in the third direction Z, and the first shell element  110  is provided with a first fixing member at a position of the first locating slot  113 . The second shell element  120  is provided with a second locating slot at two opposite ends in the third direction Z, and the second shell element  120  is provided with a second fixing member at a position of the second locating slot. One end of the bracing  170  is embedded into the first locating slot  113 , so as to preliminarily position the bracing  170  and the first shell element  110 . The bracing  170  is connected to a corresponding first fixing member, so as to fix the bracing  170  and the first shell element  110 . The other end of the bracing  170  is embedded into the second locating slot, so as to preliminarily position the bracing  170  and the second shell element  120 . The bracing  170  is connected to a corresponding second fixing member, so as to fix the bracing  170  and the second shell element  120 . After connected to the first shell element  110  and the second shell element  120 , the bracing  170  extends roughly along the first direction X. 
     The first fixing member may be a tapped hole and the second fixing member may be a tapped hole. A third fixing member corresponding to the first fixing member and a fourth fixing member corresponding to the second fixing member are disposed on the bracing  170 . Both the third fixing member and the fourth fixing member are through holes. When connecting the bracing  170  and the first shell element  110 , a first bolt  171  passes through the corresponding third fixing member on the bracing  170 , and then is in threaded fitting with the first fixing member. When connecting the bracing  170  and the second shell element  120 , a second bolt  173  passes through the corresponding fourth fixing member on the bracing  170 , and then is in threaded fitting with the second fixing member. A plurality of first fixing members on the first shell element  110  may correspond to a same bracing  170 , and the same bracing  170  and the first shell element  110  may be connected by using a plurality of first bolts  171 , so that connection strength between the first shell element  110  and the bracing  170  can be increased. Similarly, a plurality of second fixing members on the second shell element  120  may correspond to a same bracing  170 , and the same bracing  170  and the second shell element  120  may be connected by using a plurality of second bolts  173 , so that connection strength between the second shell element  120  and the bracing  170  can be increased. 
     Selection of the bracing  170  can also affect the force exerted on the cell  030 . When the first shell element  110  and the second shell element  120  are subjected to same tension so that the first shell element  110  and the second shell element  120  tend to be relatively far away, if strength of the bracing  170  is relatively high, the first shell element  110  and the second shell element  120  that are connected by the bracing  170  are not prone to being relatively far away, and if the strength of the bracing  170  is relatively low, the bracing  170  is more prone to deformation so that the first shell element  110  and the second shell element  120  are relatively far away. 
     A plurality of bracings  170  may include a first-type bracing and a second-type bracing. Sizes of the first-type bracing and the second-type bracing in the third direction Z are the same, and a size of the first-type bracing in the second direction Y is greater than a size of the second-type bracing. On a cross section perpendicular to the first direction X, a cross-sectional area of the first-type bracing is larger than a cross-sectional area of the second-type bracing, so that the first-type bracing can provide greater tension for the first shell element  110  and the second shell element  120 , so as to prevent the first shell element  110  and the second shell element  120  from being relatively far away. When used, the first-type bracing can cope with greater pressure from the cell  030 , that is, provide a greater reaction force to limit deformation of the cell  030 . To cope with a cell  030  that may have relatively large deformation during a life cycle, use of the first-type bracing enables the cell  030  to have a more stable operating condition. 
     It can be understood that the size of the first-type bracing may be alternatively set in the third direction Z to be greater than the size of the second-type bracing, so that on the cross section perpendicular to the first direction X, the cross-sectional area of the first-type bracing is also larger than the cross-sectional area of the second-type bracing. Therefore, the first-type bracing can provide greater tension for the first shell element  110  and the second shell element  120 , so as to prevent the first shell element  110  and the second shell element  120  from being relatively far away. When used, the first-type bracing can cope with greater pressure from the cell  030 , that is, provide a greater reaction force to limit the deformation of the cell  030 . 
     A battery module selects the corresponding pressure-adding beam  180  and bracing  170  based on the actual requirement of the cell  030 , so that the cell  030  can have a relatively stable shape in an entire life cycle. A spacing between the electrode plates of the cell  030  in the entire life cycle can be kept stable, so that the cell  030  can output relatively stable electric energy. Similarly, if the cell  030  is a rechargeable cell  030 , in the entire life cycle of the cell  030 , a stable electric energy input can be maintained in each charging process, so as to maintain the stable operation of the cell  030 . 
     When the cell  030  module is actually applied, if a cell  030  that is not prone to deformation is used, the cell  030  itself does not exert too much pressure on the first shell element  110  and the second shell element  120 , and the first shell element  110  and the second shell element  120  do not need to provide a great reaction force to limit the deformation of the cell  030 . In this case, only the pressure-adding beam  180  needs to be disposed in the connection area on the first shell element  110 , so that each cell group corresponds to one pressure-adding beam  180 . The second-type beam and the fourth-type beam may also be selected as the pressure-adding beam  180 , and the second-type beam and the fourth-type beam can provide a sufficient reaction force for the cell  030 , so as to limit the deformation of the cell  030 . The second-type bracing may also be used as the bracing  170 , and the second-type bracing can generate sufficient tension to provide a sufficient reaction force for the cell  030 , so as to limit the deformation of the cell  030 . 
     When the cell  030  module is actually applied, if a cell  030  that is prone to deformation as a whole in the life cycle is used, as many pressure-adding beams  180  as possible may be laid in the connection area on the first shell element  110 , so that each cell group corresponds to a plurality of pressure-adding beams  180 , and the pressure-adding beams  180  cover an entire surface of the first shell element  110  as far as possible. The third-type beam may also be selected as the pressure-adding beam  180 , and the third-type beam can provide a reaction force for the cell  030  over a larger area, so as to limit the deformation of the cell  030 . 
     When the cell  030  module is actually applied, if a cell  030  that is prone to partial severe deformation in the life cycle is used, the pressure-adding beam  180  may be disposed in a connection area corresponding to the deformation of the cell  030  on the first shell element  110 , and the first-type beam may be selected as the pressure-adding beam  180 , so that the first-type beam can provide a great reaction force to suppress the deformation of the cell  030 . The first-type bracing may also be used as the bracing  170 , and the first-type bracing can generate greater tension and provide a sufficient reaction force for the cell  030 , so as to limit the deformation of the cell  030 . 
     The cell fixing apparatus  010  further includes a third shell element  130  and a fourth shell element  140 . Both the third shell element  130  and the fourth shell element  140  are sheet metal parts, so that manufacturing costs of the third shell element  130  and the fourth shell element  140  are reduced, and the third shell element  130  and the fourth shell element  140  can have relatively high overall strength. 
     The third shell element  130  and the fourth shell element  140  are disposed at intervals in the third direction Z, and the first shell element  110 , the second shell element  120 , the third shell element  130 , and the fourth shell element  140  jointly form an accommodating cavity. 
     The cell fixing apparatus  010  further includes a first busbar support  210 , a first busbar  230 , a second busbar support  220 , and a second busbar. The first busbar support  210  is disposed between the third shell element  130  and the cell group, the cell  030  has a tab  031  facing the third shell element  130 , and the cell  030  further has a tab  031  facing the fourth shell element  140 . 
     The first busbar support  210  is provided with a fifth fixing member  211 , some fifth fixing members  211  correspond to the first fixing members, and the other fifth fixing members  211  correspond to the second fixing members. When the first shell element  110 , the second shell element  120 , and the bracing  170  are mounted, the first busbar support  210  may also be mounted together. The fifth fixing member  211  may be a through hole. After the first bolt  171  passes through a fifth fixing member  211  corresponding to the first fixing member and the third fixing member on the bracing  170 , the first bolt  171  is in threaded fitting with the first fixing member. After the second bolt  173  passes through a fifth fixing member  211  corresponding to the second fixing member and the fourth fixing member on the bracing  170 , the second bolt  173  is in threaded fitting with the second fixing member. 
     The second busbar support  220  is provided with a sixth fixing member  221 , some sixth fixing members  221  correspond to the first fixing members, and the other sixth fixing members  221  correspond to the second fixing members. When the first shell element  110 , the second shell element  120 , and the bracing  170  are mounted by using a bolt, the second busbar support  220  may also be mounted together. 
     A connection hole is provided at a position on the first busbar support  210  that corresponds to the tab  031 . The first busbar  230  is mounted to a position on the first busbar support  210  that corresponds to the connection hole. Tabs  031  that face the third shell element  130  and that are of cells  030  in the cell group are electrically connected by using the first busbar  230 . 
     Similarly, a connection hole is provided at a position on the second busbar support  220  that corresponds to the tab  031 . The second busbar is mounted to a position on the second busbar support  220  that corresponds to the connection hole. Tabs  031  that face the fourth shell element  140  and that are of cells  030  in the cell group are electrically connected by using the second busbar. 
     Both the first busbar support  210  and the second busbar support  220  are insulation brackets, so that a probability of incorrect electrical connection between electrodes can be reduced. 
     According to an actual requirement for use, two adjacent cells  030  may be connected in series by using the first busbar  230  and the second busbar, or two adjacent cells  030  may be connected in parallel by using the first busbar  230  and the second busbar. 
     It can be understood that, if both of two tabs  031  of the cell  030  face the third shell element  130 , the second busbar support  220  and the second busbar may not be disposed, and the cells  030  in the cell group can be connected in series or in parallel only by using the first busbar  230 . 
       FIG.  3    is an exploded view of a battery module according to an implementation, where a first shell element  110  and a first insulation part  240  are obtained by decomposing the battery module. 
     Referring to  FIG.  1    and  FIG.  3   , a cell fixing apparatus  010  further includes a first insulation part  240  and a second insulation part  250 . The first insulation part  240  is disposed between a first busbar  230  and a third shell element  130 . By using the first insulation part  240 , the first busbar  230  and the third shell element  130  are disposed at intervals, and the first busbar  230  is not in contact with the third shell element  130  at a minimum. The first insulation part  240  is used to insulate and isolate the first busbar  230  from the third shell element  130 , so as to reduce a probability that the third shell element  130  is energized and improve safety of the battery module. 
     Similarly, the second insulation part  250  is disposed between a second busbar and a fourth shell element  140 . By using the second insulation part  250 , the second busbar and the fourth shell element  140  are disposed at intervals, and the second busbar is not in contact with the fourth shell element  140  at a minimum. The second insulation part  250  is used to insulate and isolate the second busbar from the fourth shell element  140 , so as to reduce a probability that the fourth shell element  140  is energized and improve safety of the battery module. 
     Both the first insulation part  240  and the second insulation part  250  may use an epoxy resin board. The epoxy resin board is low in costs, easy to manufacture, and excellent in insulation performance 
     It can be understood that the first insulation part  240  and the second insulation part  250  may be alternatively made of another insulation material, so that the first insulation part  240  and the second insulation part  250  are insulated from each other on two opposite sides in a third direction Z. 
     A plurality of first air holes  241  may be further provided on the first insulation part  240  and the second insulation part  250 , and a first air hole  241  can be used to increase heat dissipation efficiency of the battery module and reduce a temperature of the battery module when the battery module operates. 
     A second air hole  131  is provided on the third shell element  130  and the fourth shell element  140 , the second air hole  131  corresponds to the first air hole  241 , and heat generated by the cell  030  causes surrounding gas to heat up. Heated gas leaves the battery module through the first air hole  241  and the second air hole  131 , so that heat of the battery module is dissipated. 
     The cell fixing apparatus  010  further includes a fifth shell element  150  and a sixth shell element  160 . Both the fifth shell element  150  and the sixth shell element  160  are sheet metal parts, so that manufacturing costs of the fifth shell element  150  and the sixth shell element  160  are reduced, and the fifth shell element  150  and the sixth shell element  160  can have relatively high overall strength. 
     The fifth shell element  150  and the sixth shell element  160  are disposed at intervals in a second direction Y, and the first shell element  110 , the second shell element  120 , the third shell element  130 , the fourth shell element  140 , the fifth shell element  150 , and the sixth shell element  160  jointly form a roughly cubic accommodating cavity. 
     The fifth shell element  150  is fixedly connected to the first shell element  110  and the second shell element  120 . The sixth shell element  160  is fixedly connected to the first shell element  110  and the second shell element  120 . The fifth shell element  150  and the sixth shell element  160  may cover two ends of the cell  030  in the second direction Y, so as to provide more comprehensive protection for the cell  030 . 
     The fifth shell element  150  and the sixth shell element  160  further have a flange extending along the second direction Y, and the flange is provided with a first fixing hole. A second fixing hole is provided on the third shell element  130  and the fourth shell element  140 , and the second fixing hole corresponds to the first fixing hole. The first fixing hole and the second fixing hole are matched by using a bolt, so that the fifth shell element  150  is connected to the third shell element  130  and the fourth shell element  140 , and the sixth shell element  160  is connected to the third shell element  130  and the fourth shell element  140 . In this way, integrity of the cell fixing apparatus  010  is enhanced, and connections among the first shell element  110 , the second shell element  120 , the third shell element  130 , the fourth shell element  140 , the fifth shell element  150 , and the sixth shell element  160  are more stable. 
     A heat dissipation hole  151  is provided on the fifth shell element  150  and the sixth shell element  160 , and the heat generated by the cell  030  in the accommodating cavity may be dissipated out of the accommodating cavity through the heat dissipation hole  151 . 
     The cell fixing apparatus  010  further includes two handles  300 , where one handle  300  is fixedly connected to the third shell element  130 , and the other handle  300  is fixedly connected to the fourth shell element  140 . When the battery module needs to be transported, a user may hold the handle  300  to apply force. 
     The battery module further includes a BMS  400  (Battery Management System, battery management system). The BMS  400  is mounted on a surface of the fifth shell element  150  that is away from the sixth shell element  160 . The BMS  400  is electrically connected to a cell group, and the cell  030  may be managed by using the BMS  400 , so that the cell  030  is in a proper operating state. 
     It can be understood that the battery module may also be used for a plurality of devices and apparatuses, for example, power supply for a mobile base station, and power supply for a transportation means such as a vehicle or a speedboat. 
     The battery module provides a first shell element  110  and a second shell element  120  that match the cell  030  for a corresponding cell  030  by using the cell fixing apparatus, and deformation of the cell  030  is limited by using the first shell element  110  and the second shell element  120 , so that the cell  030  can be in a stable operating state. 
     The foregoing description is merely implementations, but is not intended to limit the scope of the embodiments. Any variation or replacement within shall fall within the scope of the embodiments .