Patent Publication Number: US-2019198951-A1

Title: Battery module, traction battery pack and automobile

Description:
TECHNICAL FIELD 
     The disclosure relates to the technical field of new energy vehicles, and in particular, relates to a battery module, a power battery pack and a vehicle. 
     BACKGROUND 
     A power battery pack is an energy supply device for a new energy vehicle. Generally, the power battery pack is composed of a plurality of battery modules arranged side by side, and each battery module is formed of a plurality of batteries that are stacked. 
     A battery module generates heat on charging and discharging. If the heat is not dissipated in a timely manner, performance of the battery module is affected, or even danger is caused. The heat of the battery module is usually dissipated through air cooling and water cooling. 
     Existing heat dissipation solutions through air cooling for the battery module are as follows: 
     (1) An air-cooling heat-dissipation plate is placed on a bottom of the battery module, and a cell is in contact with the heat-dissipation plate only at a bottom surface, and therefore the area for heat dissipation is small, and the heat dissipation efficiency is limited. 
     (2) A heat-dissipation plate is placed on a top face and a bottom face of the battery module respectively, and a top face and a bottom face of a square electrochemical cell (the cell) are in close contact with the two heat-dissipation plates respectively. Compared with the first solution, although the second solution slightly increase the heat dissipation, the manufacturing costs are increased by 60-80%. 
     (3) The electrochemical cell conducts heat by using a vapor chamber (a heat pipe) to a heat dissipater or a tray on the bottom of the battery module, and the heat is taken away from the power battery pack by using an air-cooling structure provided on the tray. 
     In the foregoing solutions (1) and (2), according to different arrangements of the cells, a heat dissipation area proportion of the electrochemical cell (a percentage of a contact area between the heat-dissipation plate and the cell in a surface area of the electrochemical cell) varies from 5% to 25%, a heat dissipation effect is limited, and a rate of the battery module may vary from 1 to 2C. In addition, the heat-dissipation plate required in the solution (2) are large in volume and high in cost, and thus is difficult to be implemented in a power battery pack in a sealed state. 
     The air-cooling heat dissipation structure in the foregoing solution (3) has a smaller volume, but the conducting efficiency of the heat pipe is relatively low, and heat dissipation efficiency of a tray heat dissipater is not high (a heat dissipation area is limited). Therefore, in this solution, a continuous charge/discharge rate of the power battery pack can only be within 1C, and a heat dissipation problem of battery module during rapid charge/discharge (charge/discharge in a high rate of 3 to 6C) cannot be resolved. 
     In addition, all the foregoing three air-cooling heat dissipation solutions cannot be used to achieve a function of heating the power battery pack. 
     SUMMARY 
     A technical problem to be resolved in the disclosure is to provide a battery module to resolve a disadvantage that a heat dissipation area of an existing battery module air-cooling heat dissipation structure is small, and heat dissipation efficiency of the existing battery module air-cooling heat dissipation structure is limited. 
     The technical solutions used in disclosure to resolve the foregoing technical problem are as follows. 
     A battery module is provided, including: a plurality of intermediate separators stacked in a left and right direction in the battery module, a plurality of cells, a mounting plate provided on a front side of the battery module, and a ventilator fixed on the mounting plate. An intermediate heat-dissipation air plate is provided on the intermediate separator, and an intermediate heat-dissipation air passage passing through a front and rear direction is formed inside the intermediate heat-dissipation air plate. Heat is exchanged between a left side face of the intermediate heat-dissipation air plate and a right side face of a cell on a left side of the intermediate heat-dissipation air plate, and heat is exchanged between a right side face of the intermediate heat-dissipation air plate and a left side face of a cell on a right side of the intermediate heat-dissipation air plate. The intermediate heat-dissipation air passage has a first tuyere and a second tuyere, a cavity is provided between the mounting plate and a front end face of the cell, the first tuyere leads to the cavity, and the second tuyere is provided on a rear side of the battery module and leads to outside of the battery module. 
     In some embodiments of the present disclosure, the intermediate heat-dissipation air plate and the intermediate separator are integrally formed. 
     In some embodiments of the present disclosure, a guide groove is provided on an upper side and a lower side of the intermediate heat-dissipation air plate, and a guide rail that fits the guide groove through sliding insertion is provided on a corresponding location on the intermediate separator. 
     In some embodiments of the present disclosure, the guide groove extends in a front and rear direction of the upper side or the lower side of the intermediate heat-dissipation air plate, a bayonet is provided on one end of the guide groove, a limiting block is provided on a location that is on the guide rail and that corresponds to the bayonet, and the limiting block is snapped into the bayonet to limit a location at which the guide groove is inserted into the guide rail. 
     In some embodiments of the present disclosure, a snap-gauge is provided on the other end of the guide groove, and an anti-detachment barb is provided on a location that is on the guide rail and that corresponds to the snap-gauge, and the anti-detachment barb can hook the snap-gauge when the guide groove is inserted in place, to prevent the guide rail from coming out of the guide groove. 
     In some embodiments of the present disclosure, a plurality of laminates are provided inside the intermediate heat-dissipation air plate, where the laminates are configured to separate the intermediate heat-dissipation air passage into a plurality of air passage units. 
     In some embodiments of the present disclosure, a plurality of raised lines are provided in the air passage unit. 
     In some embodiments of the present disclosure, a first thermal insulation pad is provided between the left side face of the intermediate heat-dissipation air plate and the right side face of the cell on the left side of the intermediate heat-dissipation air plate, and a first thermal insulation pad is also provided between the right side face of the intermediate heat-dissipation air plate and the left side face of the cell on the right side of the intermediate heat-dissipation air plate. 
     In some embodiments of the present disclosure, the battery module includes a bottom heat-dissipation air plate provided under a plurality of cells, and heat is exchanged between an upper surface of the bottom heat-dissipation air plate and a lower surface of the cell. The bottom heat-dissipation air passage passing through a front and rear direction is formed inside the bottom heat-dissipation air plate, and the bottom heat-dissipation air passage has a third tuyere and a fourth tuyere. The third tuyere leads to the cavity, and the fourth tuyere is provided on a rear side of the battery module and leads to outside of the battery module. 
     In some embodiments of the present disclosure, the bottom heat-dissipation air plate includes a heat-dissipation plate and a plurality of fins provided side by side on a bottom of the heat-dissipation plate. A bottom protective cover is provided under the bottom heat-dissipation air plate, and the bottom heat-dissipation air passage is formed between the bottom protective cover and the plurality of fins. 
     In some embodiments of the present disclosure, a second thermal insulation pad is interposed between the heat-dissipation plate and lower surfaces of the plurality of cells. 
     In some embodiments of the present disclosure, a first side plate is fixedly provided on an external side of the cell that on a rightmost side of the battery module, and a second side plate is fixedly provided on an external side of the cell that is on a leftmost side of the battery module. 
     In some embodiments of the present disclosure, a right-side metal plate is fixed on an external side of the first side plate, and a left-side metal plate is fixed on an external side of the second side plate, a top protective cover is provided on a top of the battery module, a left side, a right side, an upper side, and a lower side of the mounting plate are respectively fixedly connected to the left metal plate, the right metal plate, the top protective cover, and the bottom protective cover, and a battery module management unit is fixedly provided on the mounting plate. 
     In some embodiments of the present disclosure, the ventilator is a fan, the mounting plate is provided with a first fan mounting hole and a second fan mounting hole, and the fan is installed in the first fan mounting hole and the second fan mounting hole. 
     In addition, the disclosure provides a power battery pack, and the power battery pack includes the plurality of battery modules. 
     In some embodiments of the present disclosure, the intermediate heat-dissipation air passages in the plurality of battery modules have a same direction. 
     In some embodiments of the present disclosure, the power battery pack includes a housing consisting of a battery tray and a battery pack sealing cover, the battery pack sealing cover is connected to a top of the battery tray, to form a space between the battery pack sealing cover and the battery tray to install the battery module, and a plurality of battery modules are provided at intervals in the space, to form an external air passage between two adjacent battery modules and/or between the battery module and an inner side wall of the housing. The external air passage leads to the intermediate heat-dissipation air passage and the cavity through the second tuyere. 
     In some embodiments of the present disclosure, a plurality of battery modules are arranged in two rows of a same quantity, and edges of two battery modules in each column are aligned, and the external air passage includes an external circulation air passage formed between the battery module and an inner side wall of the battery tray and an external central air passage formed between the two rows of battery modules. A semiconductor cooling/heating module is provided on two ends of the external central air passage, and the semiconductor cooling/heating module separates the external central air passage from the external circulation air passage. The external central air passage leads to outside of the power battery pack via the semiconductor cooling/heating module, and a ventilator for one row of battery modules pumps in air, and a ventilator for the other row of battery modules performs air blowing. 
     In some embodiments of the present disclosure, a tray heat-dissipation air passage passing through the battery tray is provided at the bottom of the battery tray, and a spoiler is provided on an opening on a side of the tray heat-dissipation air passage towards a front direction of a vehicle, and the spoiler is provided with a spoiler air passage control cover that is used to open or close the opening on the side that is of the tray heat-dissipation air passage and that is towards the front direction of the vehicle. 
     According to the battery module and the power battery pack of the disclosure, the ventilator can pump in air from the second tuyere or blow air to the second tuyere via the intermediate heat-dissipation air passage and the cavity, so that the ventilator can enable air (cold air, air of a normal temperature, or hot air) to circularly flow in the intermediate heat-dissipation air passage. Heat is exchanged between the left side face of the intermediate heat-dissipation air plate and the right side face of the cell on the left side of the intermediate heat-dissipation air plate, and is exchanged between the right side face of the intermediate heat-dissipation air plate and the left side face of the cell on the right side of the intermediate heat-dissipation air plate, that is, heat is continuously exchanged between the intermediate heat-dissipation air plate and the left and right side faces with larger areas on the cell. An inner side wall of the intermediate heat-dissipation air passage is a heat exchange surface, and a ratio of the heat exchange surface to a surface area of the cell is far greater than 25%. When heat of the batter module needs to be dissipated, heat conducted from the cell is dissipated from the heat exchange surface, and is exchanged with air flowing through the intermediate heat-dissipation air passage, to dissipate the heat of the battery module. Heat dissipation efficiency of the battery module is higher compared with that in a conventional solution of adding heat-dissipation plates to a top and a bottom. Simulation and testing show that, in the disclosure, a battery module with cell energy of 50-80 Ah can achieve continuous charge/discharge of 4C, and a battery module with cell energy of 20-40 Ah can achieve continuous charge/discharge of 6C. It can be learned that the battery module can resolve a heat dissipation problem during rapid charge/discharge (charge/discharge of a high rate of 3-6C). In addition, when the battery module needs to be heated, heat in air flowing through the intermediate heat-dissipation air passage is conducted to the cells from a heat exchange surface by using the intermediate heat-dissipation air plate, to heat the battery module. In this way, a vehicle equipped with the power battery pack can adapt to a cold area. 
     In addition, the disclosure provides a vehicle, and the vehicle includes the foregoing power battery pack. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a battery module in accordance with an embodiment of the disclosure; 
         FIG. 2  is an exploded view of a battery module in accordance with an embodiment of the disclosure; 
         FIG. 3  is a section view of a battery module obtained through vertical sectioning in a front and rear direction in accordance with an embodiment of the disclosure; 
         FIG. 4  is a section view of a battery module obtained through vertical sectioning in a left and right direction in accordance with an embodiment of the disclosure; 
         FIG. 5  is a schematic diagram of an intermediate heat-dissipation air plate of a battery module in accordance with an embodiment of the disclosure; 
         FIG. 6  is an exploded view of a battery module in accordance with an embodiment of the disclosure (a top protective cover is removed); 
         FIG. 7  is a rear view of a battery module in accordance with an embodiment of the disclosure (a top protective cover is removed); 
         FIG. 8  is a schematic diagram of assembly of a mounting plate, an intermediate heat-dissipation air plate, and a bottom heat-dissipation air plate of a battery module in accordance with an embodiment of the disclosure; 
         FIG. 9  is an exploded view of  FIG. 8 ; 
         FIG. 10  is diagram of another view of  FIG. 9 ; 
         FIG. 11  is a schematic diagram of locations of a cell and an intermediate heat-dissipation air plate of a battery module in accordance with an embodiment of the disclosure; 
         FIG. 12  is a schematic diagram of an assembly process of an intermediate separator and an intermediate heat-dissipation air plate of a battery module in accordance with another embodiment of the disclosure; 
         FIG. 13  is an enlarged view of a in  FIG. 12 ; 
         FIG. 14  is a schematic diagram of an intermediate separator of a battery module in accordance with another embodiment of the disclosure; 
         FIG. 15  is an enlarged view of b in  FIG. 14 ; 
         FIG. 16  is a schematic diagram of integral forming of an intermediate heat-dissipation air plate of a battery module on an intermediate separator in accordance with an embodiment of the disclosure; 
         FIG. 17  is a schematic diagram of an internal structure of a power battery pack in accordance with an embodiment of the disclosure; 
         FIG. 18  is an exploded view of a power battery pack in accordance with an embodiment of the disclosure (a spoiler air passage control cover is open); 
         FIG. 19  is an exploded view of a power battery pack in accordance with an embodiment of the disclosure (a spoiler air passage control cover is closed); 
     
    
    
     Reference signs in the drawings in the specification are as follows: 
     100. Battery module;  101 . First side plate;  102 . Right-side metal plate;  103 . Second side plate;  104 . Left-side metal plate;  105 . Top protective cover;  106 . Bottom protective cover; 107. Battery module management unit; 
       1 . Intermediate separator;  11 . Guide rail;  111 . Limiting block;  112 . Anti-detachment barb;  2 . Cell;  3 . Mounting plate;  31 . First fan mounting hole;  32 . Second fan mounting hole;  4 . Fan;  4   a . Air blowing fan;  4   b . Air pump-in fan;  5 . Intermediate heat-dissipation air plate;  51 . Intermediate heat-dissipation air passage;  511 . First tuyere;  512 . Second tuyere;  513 . Air passage unit;  52 . Laminate;  53 . Raised lines;  54 . Guide groove;  541 . Bayonet;  542 . Snap-gauge;  6 . Cavity;  7 . First thermal insulation pad;  8 . Bottom heat-dissipation air plate;  81 . Bottom heat-dissipation air passage;  811 . Third tuyere;  812 . Fourth tuyere;  82 . Heat-dissipation plate;  83 . Fin;  9 . Second thermal insulation pad; 
       200 . Battery tray;  201 . Tray heat-dissipation air passage;  202 . Spoiler;  203 . Spoiler air passage control cover; 
       300 . Battery pack sealing cover; 
       400 . External air passage;  401 . External circulation air passage;  402 . External central air passage; 
       500 . Semiconductor cooling/heating module 
       600 . Internal circulation air passage protective cover. 
     DETAILED DESCRIPTION 
     In order to make the technical problems resolved in the disclosure, technical solutions and beneficial effects more clear, the disclosure is described in detail below with reference to the accompanying drawings and embodiments. It should be understood that specific embodiments described herein are merely intended to explain the disclosure instead of limiting the disclosure. 
     Hereinafter, for ease of clear description, it is defined that when a battery module is normally placed, an orientation at which a mounting plate is located is a front side of a battery module, and the front side is used as a reference for a left, right, rear, upper (top), and lower (bottom) of the battery module. For a specific orientation, refer to  FIGS. 1, 2 and 6 . 
     As shown in  FIGS. 1-7 , a battery module  100  provided in an embodiment of the disclosure includes a plurality of intermediate separators  1  stacked in a left and right direction in the battery module  100 , a plurality of square cells  2 , a mounting plate  3  provided on a front side of the battery module, and a fan  4  fixed on the mounting plate  3  and used as a ventilator. An intermediate heat-dissipation air plate  5  is provided on the intermediate separator  1 , and an intermediate heat-dissipation air passage  51  passing through a front and rear direction is formed inside the intermediate heat-dissipation air plate  5 . Heat is exchanged between a left side face of the intermediate heat-dissipation air plate  5  and a right side face of a cell  2  on a left side of the intermediate heat-dissipation air plate, and is exchanged between a right side face of the intermediate heat-dissipation air plate  5  and a left side face of a cell  2  on a right side of the intermediate heat-dissipation air plate. Areas of an upper surface, a lower surface, a front side face, and a rear side face of the square cell  2  are much smaller than areas of a left side face and a right side face. The intermediate heat-dissipation air passage  51  has a first tuyere  511  and a second tuyere  512 , and a cavity  6  is provided between the mounting plate  3  and a front end face of the cell  2 . The first tuyere  511  leads to the cavity  6 , and the second tuyere  512  is provided on a rear side of the battery module  100  and leads to outside of the battery module  100 . 
     In this embodiment, two adjacent intermediate separators  1  are snap-fitted for stacking, and have a straining function on the cells  2 . 
     In this embodiment, as shown in  FIGS. 1 and 8 , there are two fans  4 . The mounting plate  3  is provided with a first fan mounting hole  31  and a second fan mounting hole  32 , and the fans  4  are mounted in the first fan mounting hole  31  and the second fan mounting hole  32 , and are arranged at intervals in a left and right direction in the mounting plate  3 . Certainly, in other embodiments, there may be one or more than three fans  4 . This is designed based on a heat dissipation requirement. 
     Air pump-in in this specification means to generate negative pressure in the cavity  6  by using an air pump-in fan, and pump in air from a rear side of the battery module  100 , so that air from the rear side of the battery module  100  is exhausted from a front side of the battery module  100  after flowing through the intermediate heat-dissipation air passage  51  (a bottom heat-dissipation air passage  81 ), the cavity  6 , and the fan  4 . Air blowing herein means to bring air from the front side of the battery module  100  by using an air blowing fan, so that air from the front side of the battery module  100  blows out from the rear side of the battery module  100  after flowing through the fan  4 , the cavity  6 , and the intermediate heat-dissipation air passage  51  (the bottom heat-dissipation air passage  81 ). 
     In this embodiment, the fan  4  with an air pump-in function is used as an example for description. The first tuyere  511  is an air outlet of the intermediate heat-dissipation air passage  51 , and the second tuyere  512  is an air inlet of the intermediate heat-dissipation air passage  51 , respectively. The fan  4  may pump in air from the second tuyere  512  via the intermediate heat-dissipation air passage  51  and the cavity  6 , that is, air outside the battery module  100  enters the second tuyere  512  and blows through the intermediate heat-dissipation air passage  51  and the cavity  6 , to be exhausted from the battery module  100  via a front side of the fan  4 . 
     When heat of the battery module  100  needs to be dissipated, the fan  4  pumps in air (air of a normal temperature or cold air) outside the battery module  100  into the battery module  100 , and heat of two larger side faces (left and right side faces) of the cells  2  is conducted to the intermediate heat-dissipation air plate  5  and is dissipated to the intermediate heat-dissipation air passage  51  along an inner side wall (a heat exchange surface) of the intermediate heat-dissipation air passage  51 . The heat is blown away when air flows through the intermediate heat-dissipation air passage  51 , to achieve heat dissipation of the cell  2 . In turn, when the battery module  100  needs to be heated, the fan  4  pumps in air (hot air) outside the battery module  100  into the battery module  100 , and heat in the air is conducted to the two larger side faces (the left and right side faces) of the cells  2  along the inner side wall of the intermediate heat-dissipation air passage  51  by using the intermediate heat-dissipation air plate  5 , that is, the cell  2  is heated when air flows through the intermediate heat-dissipation air passage  51 . 
     Certainly, in other embodiments, the fan  4  can also blow air. The first tuyere  511  is an air inlet of the intermediate heat-dissipation air passage  51 , and the second tuyere  512  is an air outlet of the intermediate heat-dissipation air passage  51 , respectively. The fan  4  may blow air to the second tuyere  512  via the intermediate heat-dissipation air passage  51  and the cavity  6 , that is, air outside the battery module  100  is brought in from a front side of the fan  4 , and flows through the cavity  6  and the intermediate heat-dissipation air passage  51 , and blows out from the second tuyere  512  (a rear side of the battery module  100 ). 
     In this embodiment, as shown in  FIGS. 5 and 16 , the intermediate heat-dissipation air plate  5  and the intermediate separator  1  are integrally formed. For example, the intermediate heat-dissipation air plate  5  can be integrally formed (embedded into) on the intermediate separator  1  through injection molding, so that the intermediate separator  1  can be assembled in an arbitrary manner while having good extensibility and being simple in assembly, thereby improving assembly efficiency of a product. A T-shaped structure is provided on both sides of the intermediate heat-dissipation air plate  5  in a height direction, and the T-shaped structure has the functions of facilitating injection molding positioning and improving overall strength of a product. 
     As shown in  FIG. 5 , a plurality of laminates  52  are provided inside the intermediate heat-dissipation air plate  5 , where the laminates are configured to separate the intermediate heat-dissipation air passage  51  into a plurality of air passage units  513 , and a plurality of raised lines  53  are provided in the air passage unit  513 . In this embodiment, specifically, there are eight laminates  52 . The intermediate heat-dissipation air passage  51  is divided into nine identical square air passage units  513 , and four raised lines  53  are provided in each air passage unit  513 . The air passage unit  513  and the raised line  53  are integrally extruded, so that strength of an air passage plate can be greatly improved and extrusion deformation can be greatly reduced. In addition, the four raised lines  53  enlarge a heat exchange area of the intermediate heat-dissipation air passage  51 , and enhance a turbulence scale of air flowing through the intermediate heat-dissipation air plate, thereby improving a heat exchange coefficient, and enhancing a heat dissipation effect. 
     As shown in  FIG. 2 , a first thermal insulation pad  7  is provided between the left side face of the intermediate heat-dissipation air plate  5  and the right side face of the cell  2  on the left side of the intermediate heat-dissipation air plate, and a first thermal insulation pad is also provided between the right side face of the intermediate heat-dissipation air plate  5  and the left side face of the cell  2  on the right side of the intermediate heat-dissipation air plate. That is, the first thermal insulation pad  7  is provided between the intermediate heat-dissipation air plate  5  and the unit cells  2  on both sides. The first thermal conductive insulating pad has a thermal conductivity of 1-2 W/Mk, and has good wear resistance and insulation. The first thermal conductive insulating pad may be, but is not limited to, thermal rubber, a UTP100 thermal insulation sheet, or the like. 
     In some embodiments of the present disclosure, as shown in  FIGS. 2-11 , the battery module  100  includes a bottom heat-dissipation air plate  8  provided under the plurality of cells  2 . Heat is exchanged between an upper surface of the bottom heat-dissipation air plate  8  and a lower surface of the cell  2 , and a bottom heat-dissipation air passage  81  passing through a front and rear direction is formed inside the bottom heat-dissipation air plate  8 . The bottom heat-dissipation air passage  81  has a third tuyere  811  and a fourth tuyere  812 , the third tuyere  811  leads to the cavity  6 , and the fourth tuyere  812  is provided on the rear side of the battery module  100  and leads to outside of the battery module  100 . 
     Corresponding to the fan  4  with an air pump-in function, the third tuyere  811  is an air outlet of the bottom heat-dissipation air passage  81 , and the fourth tuyere  812  is an air inlet of the bottom heat-dissipation air passage  81 , respectively. The fan  4  can pump in air from the fourth tuyere  812  via the bottom heat-dissipation air passage  81  and the cavity  6 . That is, air outside the battery module  100  enters the fourth tuyere  812  and blows through the bottom heat-dissipation air passage  81 , the cavity  6 , to be exhausted from the battery module  100  via a front side of the fan  4 . 
     Certainly, in other embodiments, corresponding to the fan  4  with an air blowing function, the third tuyere  811  is an air inlet of the bottom heat-dissipation air passage  81 , and the fourth tuyere  812  is an air outlet of the bottom heat-dissipation air passage  81 . The fan  4  may blow air to the fourth tuyere  812  via the bottom heat-dissipation air passage  81  and the cavity  6 , that is, air outside the battery module  100  is brought in from a front side of the fan  4 , and flows through the cavity  6  and the bottom heat-dissipation air passage  81 , and blows out from the fourth tuyere  812  (the rear side of the battery module  100 ). 
     In this embodiment, the bottom heat-dissipation air passage  81  and the intermediate heat-dissipation air passage  51  are independent of each other. 
     In this embodiment, as shown in  FIG. 2 , the bottom heat-dissipation air plate  8  is a fin dissipater, and includes a heat-dissipation plate  82  and a plurality of fins  83  provided side by side on a bottom of the heat-dissipation plate  82 , a bottom protective cover  106  is provided under the bottom heat-dissipation air plate  8 , and the bottom heat-dissipation air passage  81  is formed between the bottom protective cover  106  and the plurality of fins  83 . A second thermal insulation pad  9  is interposed between the heat-dissipation plate  82  and lower surfaces of the plurality of cells  2 . Functions of the second thermal insulation pad  9  and the first thermal insulation pad  7  are similar. 
     During a start of the fan  4 , a negative pressure area is formed in the cavity  6  among the first tuyere  511  and the third tuyere  811  and the mounting plate  3 . A magnitude and distribution of the negative pressure are related to a static pressure, a rotational speed, and a blast capacity of the fan, and optimal fan model, quantity, and mounting location can be determined through simulation and testing. 
     In this embodiment, a quantity of the intermediate heat-dissipation air plates  5  is related to arrangement of the cells  2 . As shown in  FIGS. 6 and 11 , in this embodiment, both the left and right sides of the intermediate heat-dissipation air plate  5  are provided with two cells  2 , the two cells  2  are aligned in a front and rear direction, and the plurality of cells  2  are arranged in two rows in a left and right direction. In this way, heat is exchanged between the left side face of the intermediate heat-dissipation air plate  5  and right side faces of the two cells  2  on the left side of the intermediate heat-dissipation air plate, and is exchanged between the right side face of the intermediate heat-dissipation air plate  5  and left side faces of the two cells  2  on the right side of the intermediate heat-dissipation air plate. The intermediate heat-dissipation air plate  5  is located between the four cells  2 , so that a volume of the battery module can be minimized while ensuring the same heat dissipation efficiency of the battery module. 
     Certainly, in other embodiments, one cell  2  or more than three cells  2  can be respectively provided on the left and right sides of intermediate heat-dissipation air plate  5 . 
     When heat of the battery module  100  needs to be dissipated, the fan  4  pumps in air (air of a normal temperature or cold air) outside the battery module  100  into the battery module  100  (the intermediate heat-dissipation air passage  51  and the bottom heat-dissipation air passage  81 ) via the second tuyere  512  and the fourth tuyere  812 , and heat of two larger side faces (left and right side faces) of the cells  2  is conducted to the intermediate heat-dissipation air plate  5  and is dispersed to the intermediate heat-dissipation air passage  51  along an inner side wall (a heat exchange surface) of the intermediate heat-dissipation air passage  51 . The heat is blown away when air flows through the intermediate heat-dissipation air passage  51 , to achieve heat dissipation of the cell  2 . On the contrary, when the battery module  100  needs to be heated, the fan  4  pumps in air (hot air) outside the battery module  100  into the battery module  100 , and heat in the air is conducted to the two larger side faces (the left and right side faces) of the cells  2  along the inner side wall of the intermediate heat-dissipation air passage  51  by using the intermediate heat-dissipation air plate  5 , that is, the cell  2  is heated when air flows through the intermediate heat-dissipation air passage  51 . 
     As shown in  FIGS. 8-11 , in this embodiment, a plurality of intermediate heat-dissipation air plates  5  are provided in parallel. Sizes and proportions of air inlets of the plurality of intermediate heat-dissipation air plates  5  and a plurality of bottom heat-dissipation air plates  8  are optimized, so that an optimal dissipation effect and optimal temperature consistency can be achieved, thereby increasing a charge/discharge rate and a life of the battery module. Certainly, the quantity of the intermediate heat-dissipation air plates  5  is designed as required based on a quantity and arrangement of the cells. 
     Certainly, in other embodiments, the fan  4  may also blow air. The fan  4  may blow air to the second tuyere  512  via the intermediate heat-dissipation air passage  51  and the cavity  6 , that is, air outside the battery module  100  is brought in from an external side of the fan, and flows through the cavity  6  and the intermediate heat-dissipation air passage  51 , and blows out from the second tuyere  512 . 
     As shown in  FIG. 2 , a first side plate  101  is fixedly provided on an external side of the cell  2  that is on a rightmost side of the battery module  100 , and a right-side metal plate  102  is fixed on an external side of the first side plate  101 . A second side plate  103  is fixedly provided on an external side of the cell  2  that is on a leftmost side of the battery module  100 , and a left-side metal plate  104  is fixed on an external side of the second side plate. A top protective cover  105  is provided on a top of the battery module  100 , and a bottom protective cover  106  is provided on a bottom of the battery module  100 . The bottom heat-dissipation air plate  8  is provided between a lower surface of the plurality of cells  2  and the bottom protective cover  106 , and a left side, a right side, an upper side, and a lower side of the mounting plate  3  are respectively fixedly connected to the left-side metal plate  104 , the right-side metal plate  102 , the top protective cover  105 , and the bottom protective cover  106  by using a bolt. The top protective cover  105  is composed of three plates arranged side by side. 
     In addition, as shown in  FIG. 2 , a battery module management unit  107  is fixedly provided on the mounting plate  3 . 
     According to the battery module in the foregoing embodiment of the disclosure, heat is exchanged between the left side face of the intermediate heat-dissipation air plate  5  and the right side face of the cell  2  on the left side of the intermediate heat-dissipation air plate, and is exchanged between the right side face of the intermediate heat-dissipation air plate  5  and the left side face of the cell  2  on the right side of the intermediate heat-dissipation air plate. That is, heat is continuously exchanged between the intermediate heat-dissipation air plate  5  and the left and right side faces with larger areas on the cell  2 , and heat can be exchanged between the bottom heat-dissipation air plate  8  and a bottom of the cells  2 . A ratio of a sum of a heat exchange surface of the intermediate heat-dissipation air passage  51  and a heat exchange surface of the bottom heat-dissipation air passage  81  and a surface area of the cell is greater than or equal to (≤) 75% (a ratio can be up to 75% in case of a C17 electrochemical cell, and a ratio can be up to 85% in case of a C20 electrochemical cell), and therefore heat dissipation efficiency is high. Simulation and testing show that, in the disclosure, a battery module with a cell capacity of 50-80 Ah can achieve continuous charge/discharge of 4C, and a battery module with a cell capacity of 20-40 Ah can achieve continuous charge/discharge of 6C. It can be learned that the battery module can be used to solve a heat dissipation problem during rapid charge/discharge (charge/discharge of a high rate of 3-6C). In addition, when the battery module needs to be heated, heat in air flowing through the intermediate heat-dissipation air passage  51  is conducted to the cells  2  from the heat exchange surface of the intermediate heat-dissipation air passage  51  by using the intermediate heat-dissipation air plate  5 , and heat in air flowing through the bottom heat-dissipation air passage  81  is conducted to the cells  2  from the heat exchange surface of the bottom heat-dissipation air passage  81  by using the bottom heat-dissipation air plate  8 , to heat the battery module  100 . In this way, a vehicle equipped with the battery module  100  can adapt to a cold area. 
     In addition, as shown in  FIGS. 12-15 , in another embodiment of the disclosure, the intermediate heat-dissipation air plate  5  is fixed on (snapped into) the intermediate separator  1  by using a detachable connection. 
     As shown in  FIGS. 12 and 15 , a guide groove  54  is provided on an upper side and a lower side of the intermediate heat-dissipation air plate  5 , and a guide rail  11  that fits the guide groove  54  through sliding insertion is provided on a corresponding location on the intermediate separator  1 . The guide groove  54  extends in a front and rear direction on the upper side or the lower side of the intermediate heat-dissipation air plate  5 , a bayonet  541  is provided on one end of the guide groove  54 , and a limiting block  111  is provided on a location that is on the guide rail  11  and that corresponds to the bayonet  541 . The limiting block  111  is snapped into the bayonet  541  to limit a location at which the guide groove  54  is inserted into the guide rail  11 . A snap-gauge  542  is provided on the other end of the guide groove  54 , and an anti-detachment barb  112  is provided on a location that is on the guide rail  11  and that corresponds to the snap-gauge  542 , and the anti-detachment barb  112  can hook the snap-gauge  542  when the guide groove  54  is inserted in place, to prevent the guide rail  11  from coming out of the guide groove  54 , thereby steadily mounting the intermediate heat-dissipation air plate  5  on the intermediate separator  1 . 
     In this specification, the one end that is of the guide groove  54  and that is provided with the bayonet  541  is a rear end of the guide groove (based on an orientation of the battery module  100 ), and the other end provided with the snap-gauge  542  is a front end of the guide groove  54  (based on the orientation of the battery module  100 ). The one end that is of the guide rail  11  and that is provided with the limiting block  111  is a rear end of the guide rail (based on the orientation of the battery module  100 ), and the other end that is of the guide rail  11  and that is provided with the anti-detachment barb  112  is a front end of the guide rail (based on the orientation of the battery module  100 ), respectively. 
     Compared with the integrally formed intermediate separator  1  shown in  FIG. 16 , in a manner of using a detachable connection, a precision requirement on an injection mold of the intermediate separator  1  can be reduced, and in addition, the intermediate heat-dissipation air plate  5  is separately formed, so that the intermediate heat-dissipation air passage  51  in the intermediate heat-dissipation air plate  5  is easier to mold, and the cost for assembly and repair is low. 
     In addition, as shown in  FIGS. 17-19 , an embodiment of the disclosure provides a power battery pack, and the power battery pack includes a plurality of battery modules  100  and a housing consisting of a battery tray  200  and a battery pack sealing cover  300 . The battery pack sealing cover  300  is connected to a top of the battery tray  200 , to form a space between the battery pack sealing cover  300  and the battery tray  200  to install the battery module  100 . The plurality of battery modules  100  are provided at intervals in the space, to form an external air passage  400  between two adjacent battery modules  100  and/or between the battery module  100  and an inner side wall of the housing, and the external air passage  400  leads to the intermediate heat-dissipation air passage  51  and the cavity  6  via the second tuyere  512 . In addition, the external air passage  400  leads to the bottom heat-dissipation air passage  81  and the cavity  6  via the fourth tuyere  812 . 
     In this embodiment, intermediate heat-dissipation air passages  51  in the plurality of battery modules  100  have a same direction. In addition, bottom heat-dissipation air passages  81  of the plurality of battery modules  100  have a same direction. 
     As shown in  FIG. 17 , the plurality of battery modules  100  are arranged in two rows of a same quantity, that is, each row has four battery modules  100  (that is, each column has two battery modules  100 ), and edges of the two battery modules  100  in each column are aligned. In this way, intermediate heat-dissipation air passages  51  in two battery modules  100  in a same column are collinear, and bottom heat-dissipation air passages  81  of the two battery modules  100  in the same column are also collinear. 
     In this embodiment, the external air passage  400  includes an external circulation air passage  401  formed between the battery module  100  and the inner side wall of the battery tray  200  and an external central air passage  402  formed between the two rows of battery modules  100 . A semiconductor cooling/heating module  500  is provided on two ends of the external central air passage  402 , the external central air passage  402  leads to outside of the power battery pack via the semiconductor cooling/heating module  500 , and the semiconductor cooling/heating module  500  separates the external central air passage  402  from the external circulation air passage  401 . 
     As shown in  FIGS. 18 and 19 , an internal circulation air passage protective cover  600  is provided between the battery pack sealing cover  300  and the battery tray  200 . 
     As shown in  FIG. 17 , the two battery modules  100  in the same column are aligned in a left and right direction, and the four battery modules  100  in the same row are aligned in a front and rear direction. The fans for one row of battery modules  100  pump air in, and the fans for the other row of battery modules  100  perform air blowing. 
     In some embodiments of the present disclosure, as shown in  FIG. 17 , battery modules  1 #,  2 #,  3 #, and  4 # are in a same row, and battery modules  5 #,  6 #,  7 #, and  8 # are in a same row. The battery module  1 # and the battery module  8 # are in a same column, the battery module  2 # and the battery module  7 # are in a same column, the battery module  3 # and the battery module  6 # are in a same column, and the battery module  4 # and the battery module  5 # are in a same column. Rear sides of the battery modules  1 #,  2 #,  3 #, and  4 # are facing rear sides of the battery modules  5 #,  6 #,  7 #, and  8 #. Fans  4  on the battery modules  1 #,  2 #,  3 #, and  4 # are used for blowing air, and form air blowing fans  4   a , and fans  4  on the battery modules  5 #,  6 #,  7 #, and  8 # are used for pumping in air, and form air pump-in fans  4   b . In this way, an air circulation path in the power battery pack is as follows: external circulation air passage→battery modules  1 #,  2 #,  3 #, and  4 #→external central air passage→battery modules  5 #,  6 #,  7 #, and  8 #→external circulation air passage. 
     As shown in  FIGS. 18 and 19 , a tray heat-dissipation air passage  201  passing through the battery tray  200  is provided at the bottom of the battery tray  200 , and a spoiler  202  is provided on an opening on a side of the tray heat-dissipation air passage  201  towards a front direction of a vehicle, and the spoiler  202  is provided with a spoiler air passage control cover  203  that is used to open or close the opening on the side that is of the tray heat-dissipation air passage  201  and that is towards the front direction of the vehicle. 
     Based on the power battery pack of the battery module  100 , the semiconductor cooling/heating module  500  provided on the two ends of the external central air passage  402  can achieve heat exchange between interior of the battery module  100  and the external air passage  400 . In a case in which sealing of the power battery pack is not changed, heat dissipation (cooling) and heating functions of the power battery pack can be achieved by using air as a coolant. 
     The power battery pack can implement a heating mode and a multi-level cooling (heat dissipation) mode of the power battery pack. Details are as follows: 
     Heating Mode 
     As shown in  FIGS. 17 and 19 , when a temperature of the cell  2  is excessively low (for example, ≥10° C.), the heating mode is enabled. The spoiler air passage control cover  203  on the front end of the power battery pack is closed, and the tray heat-dissipation air passage  201  is isolated from the outside of the power battery pack, and therefore no air enters. A semiconductor heat exchange module  500  enables the heating mode, and the air blowing fan  4   a  used for blowing air and the air pump-in fan  4   b  used for pumping in air for the serially-connected internal air passages (the intermediate heat-dissipation air passage  51  and the bottom heat-dissipation air passage  81 ) and the external air passage  400  are turned on. Air is heated when flowing through the semiconductor heat exchange module  500 , and then enters intermediate heat-dissipation air passages  51  and bottom heat-dissipation air passages  81  in the battery modules  1 #,  2 #,  3 #, and  4 # via the air blowing fan  4   a , to achieve uniform and efficient heating of the battery modules  100   1 #,  2 #,  3 #, and  4 #. Then hot air from the battery modules  100   1 #,  2 #,  3 #, and  4 # flows through the external central air passage  402  and enters intermediate heat-dissipation air passages  51  and bottom heat-dissipation air passages  81  in the battery modules  100   5 #,  6 #,  7 #, and  8 #, to achieve uniform and efficient heating of the battery modules  100   5 #,  6 #,  7 #, and  8 #. Finally, the air pump-in fan  4   b  exhausts the air into the external circulation air passage  401 , and so on. 
     Cooling (Heat Dissipation) Mode 
     Level 0 cooling: As shown in  FIGS. 17 and 18 , if a temperature of a vehicle is slightly high during driving, the spoiler air passage control cover  203  on the front end of the power battery pack can be opened. Air flows through the tray heat-dissipation air passage  201  at a high speed during driving, and takes away heat transferred from the battery module  100  to the battery tray  200 , to dissipate heat of the battery module  100 . 
     Level 1 cooling: A current direction of the semiconductor heat exchange module  500  is changed (opposite to that during heating), to convert the semiconductor heat exchange module  500  into a cooling mode, and the air blowing fan  4   a  used for blowing air is turned on (the air pump-in fan  4   b  used for pumping in air is not turned on), to cool (dissipate heat of) the battery module  100 . 
     Level 2 cooling: When the semiconductor heat exchange module  500  is in the cooling mode, the air blowing fan  4   a  used for blowing air and the air pump-in fan  4   b  used for pumping in air are simultaneously turned on. Compared with the level 1 cooling mode, the air blowing fan  4   a  and the air pump-in fan  4   b  are connected in series, a static pressure difference between the air blowing fan  4   a  and the air pump-in fan  4   b  is increased, and flowing speeds of air in the internal air passages (the intermediate heat-dissipation air passage  51  and the bottom heat-dissipation air passage  81 ) in the battery module  100  are increased. Therefore, a heat dissipation effect is improved. 
     Level 0 cooling can be used only during driving of a vehicle, and level 1 and level 2 cooling can be used in any condition. Quantities of air blowing fans  4   a  and air pump-in fans  4   b  that are turned on can be adjusted and a power of the semiconductor heat exchange module  500  can be adjusted, to achieve different cooling effects, thereby meeting heat dissipation requirements of a vehicle during large-rate charge and in various different driving conditions. 
     According to the power battery pack in the foregoing embodiment of the disclosure, a ventilator of each battery module can pump in air from the second tuyere or blow air to the second tuyere via the intermediate heat-dissipation air passage and the cavity, so that air can circularly flow in the intermediate heat-dissipation air passage. Heat is continuously exchanged between two side surfaces of the intermediate heat-dissipation air passage that are in a stacking direction of the intermediate separators and side faces of larger areas on the cell, and an inner side wall of the intermediate heat-dissipation air passage is a heat dissipation surface, and a ratio of the heat dissipation surface to a surface area of the cell is far greater than 25%, and heat dissipation efficiency is high. Simulation and testing show that a battery module with cell energy of 50-80 Ah can achieve continuous charge/discharge of 4C, and a battery module with cell energy of 20-40 Ah can achieve continuous charge/discharge of 6C. It can be learned that the power battery pack of the disclosure can resolve a heat dissipation problem during rapid charge/discharge (charge/discharge of a high rate of 3-6C). In addition, the plurality of battery modules of the power battery pack are provided at intervals in the space between the battery pack sealing cover and the battery tray, to form an external air passage between the battery modules and the inner side wall of the battery tray. The external air passage leads to the intermediate heat-dissipation air passage and the cavity through the second tuyere, so that the cooling/heating module provided in the external air passage can heat or cool air in the external air passage, to cool or heat the power battery pack. 
     In addition, the disclosure provides a vehicle, and the vehicle includes the foregoing power battery pack. 
     The foregoing descriptions are merely preferred embodiments of the disclosure, but are not intended to limit the disclosure. Any modification, equivalent replacement, improvement, or the like made within the spirit and principle of the disclosure should fall within the protection scope of the disclosure.