Battery modules and battery packs

Abstract

The present invention provides a battery module and a battery pack. The battery module includes: a frame body, which is heat-conductive, has a peripheral wall and a receiving cavity; two end plates, which are respectively fixedly connected to the two ends of the axial opening of the frame body, and respectively seal the two ends of the axial opening of the frame body to form a sealed space together with the peripheral wall; a plurality of battery cells, which are received in the sealed space, and each battery cell has at least one secondary battery; the battery module also includes: a coolant, which is received in the sealed space, contacts the peripheral wall and impregnates each secondary battery. The battery pack includes: a lower box body, which has a bottom wall; at least one battery pack row, each battery pack row includes at least one battery module, each battery module is arranged on the bottom wall, each battery module is associated with at least one sub-coolant flow path, and the sub-coolant flow paths of the battery modules of each battery pack row form the total coolant flow path of the battery module row. The provision of the coolant greatly improves the heat dissipation effect of the battery module and the battery pack.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a battery module and a battery pack. Background Art

[0002] Secondary batteries have various forms. According to the type of shell, secondary batteries can be divided into pouch-type secondary batteries and can-type secondary batteries. The shell of the pouch-type secondary battery is made of a laminate sheet including a polymer layer and a metal layer. The shell of the can-type secondary battery is generally composed of a metal shell and a metal top cover sheet.

[0003] A battery module generally arranges a plurality of secondary batteries and fixes them through a corresponding frame.

[0004] A battery module using can-type secondary batteries is usually formed by arranging multiple can-type secondary batteries and pressing two front and rear end plates together, then welding and fixing two side plates to the two end plates, and finally installing an external water cooling system (even a thermal conductive silicone pad) at the bottom of the multiple can-type secondary batteries.

[0005] A battery module using pouch-type secondary batteries is usually assembled into battery cells by sticking the pouch-type secondary batteries on a metal plate (usually an aluminum plate) and then arranging and fixing the battery cells. Finally, like a battery module using can-type secondary batteries, an external water cooling system (even a thermally conductive silicone pad) is installed at the bottom of the multiple battery cells to achieve heat conduction from the pouch-type secondary batteries to the water cooling system through the metal plate.

[0006] However, whether it is a battery module using can-type secondary batteries or a battery module using pouch-type secondary batteries, further improvements are needed in the heat dissipation of the battery module to enhance the heat dissipation effect of the battery module.

[0007] Similarly, when a battery module using can-type secondary batteries or a battery module using pouch-type secondary batteries is applied to a battery pack, further improvements are needed in the heat dissipation of the battery pack to enhance the heat dissipation effect of the battery pack. Summary of the invention

[0008] In view of the problems existing in the background technology, an object of the present invention is to provide a battery module and a battery pack, which can improve the heat dissipation effect of the battery module and the battery pack.

[0009] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a battery module, which includes: a frame, which is heat-conductive, has a peripheral wall and a receiving cavity surrounded by the peripheral wall, which is circumferentially closed but open at both axial ends; two end plates, which are respectively fixedly connected to the two ends of the axial opening of the frame, and respectively seal the two ends of the axial opening of the frame to form a sealed space together with the peripheral wall; a plurality of battery cells, which are accommodated in the sealed space, and each battery cell has at least one secondary battery; the battery module also includes: a coolant, which is accommodated in the sealed space, contacts the peripheral wall and impregnates each secondary battery.

[0010] In order to achieve the above-mentioned object, the second aspect of the present invention provides a battery pack, which includes: a lower box and at least one battery pack row. The lower box has a bottom wall. Each battery pack row includes at least one battery module, each battery module is arranged on the bottom wall of the lower box, each battery module has a shell forming a sealed space and a plurality of battery cells accommodated in the sealed space, each battery cell has at least one secondary battery; each battery module is associated with at least one sub-cooling liquid flow passage, and the sub-cooling liquid flow passage of the battery module of each battery pack row forms a total cooling liquid flow passage of the battery module row.

[0011] In order to achieve the above-mentioned purpose, the third aspect of the present invention provides a battery pack, which includes: a lower box body, having a bottom wall, and a flow channel is arranged in the bottom wall; at least one battery module described in the first aspect is supported on the bottom wall of the lower box body.

[0012] The beneficial effects of the present invention are as follows:

[0013] In the battery module and the battery pack according to the present invention, the provision of the coolant greatly improves the heat dissipation effect of the battery module and the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an exploded stereoscopic diagram of a battery module according to the present invention, wherein the battery cells of the battery module adopt pouch-type secondary batteries and the pole ears are bent, and the bending of the pole ears can be done when the battery cells are formed, or not bent when the battery cells are formed but bent when the battery module is formed.

[0015] Figure 2 yes Figure 1 An assembly diagram of some of the components shows the assembly relationship between the end plate and multiple battery cells.

[0016] Figure 3 yes Figure 1 Assembly diagram of the .

[0017] Figure 4 3D is a perspective view of a battery cell in a battery module according to the present invention, wherein the battery cell adopts a pouch-type secondary battery and each tab is not bent.

[0018] Figure 5 yes Figure 4 An exploded perspective view of an embodiment of the present invention, wherein each tab is not bent.

[0019] Figure 6 yes Figure 4 An exploded perspective view of another embodiment of the present invention, wherein each tab is not bent.

[0020] Figure 7It is a three-dimensional cutaway view of some components of a battery module according to the present invention, showing a sealed space enclosed by a frame and two end plates.

[0021] Figure 8 is a cross-sectional view of a battery module according to the present invention.

[0022] Fig. 9 Schematic diagram of the coolant distribution of the battery module according to the present invention.

[0023] Fig.10 is an exploded perspective view of a battery pack according to an embodiment of the present invention.

[0024] Fig.11 yes Fig.10 Assembly stereogram of .

[0025] Fig.12 yes Fig.10 A cutaway stereogram of the block in FIG.

[0026] Fig.13 yes Fig.11 A cutaway stereogram of a .

[0027] Fig.14 is a cutaway perspective view of a battery pack according to another embodiment of the present invention.

[0028] Fig.15 is a cutaway perspective view of a battery pack according to another embodiment of the present invention.

[0029] Fig.16 is a cutaway perspective view of a battery pack according to yet another embodiment of the present invention.

[0030] Fig.17 yes Fig.10 A schematic diagram of another embodiment of the flow channel of the lower box body.

[0031] Fig.18 yes Fig.10 A three-dimensional view of another embodiment of a battery module in FIG.

[0032] Fig.19 yes Fig.18 An exploded perspective view of the shell in FIG.

[0033] Fig. 20 is a perspective view of another embodiment of a battery pack according to the present invention, which adopts Figure 3 Battery module.

[0034] The reference numerals are described as follows:

[0035] 1 battery module 17 elastic buffer pad

[0036] 11 frame 18 sealing ring

[0037] 111 Wall V1 Balancing Valve

[0038] 1111 first opening V2 first one-way valve

[0039] 1112 second opening V21 first upper cavity

[0040] 1113 third opening V22 first intermediate cavity

[0041] 1114 end face V23 first lower cavity

[0042] 112 receiving chamber V24 spring

[0043] S sealed space V25 first sphere

[0044] 12 End plate V3 second check valve

[0045] 121 plate body V31 first upper channel

[0046] 1211 protrusion V32 second lower channel

[0047] 1212 Accommodating concave portion V33 Second sphere

[0048] 122 Insert P sealing sheet

[0049] 1221 stop surface 19 housing

[0050] 1222 tab 191 upper shell

[0051] 13 battery unit 192 lower housing

[0052] 131 secondary battery 2 lower box

[0053] 1311 main body 21 bottom wall

[0054] 1312 side B block

[0055] 1313 tab R notch

[0056] 132 fixed block U flow path unit

[0057] 1321 positioning groove U1 flow channel

[0058] 1322 positioning convex part U2 flow hole

[0059] 1323 Positioning concave portion U3 first communicating hole

[0060] 1324 groove U4 connecting pipe

[0061] 14 Cooling liquid U5 second connecting hole

[0062] 15 Connector 3 Connector

[0063] 16 Output piece F1 flow channel side passage

[0064] 161 protrusion F2 connecting pipe side passage DETAILED DESCRIPTION

[0065] The battery module and the battery pack according to the present invention will be described in detail below with reference to the accompanying drawings.

[0066] First, a battery module according to a first aspect of the present invention will be described.

[0067] like Figures 1 to 9 As shown, the battery module 1 according to the first aspect of the present invention comprises: a frame 11, two end plates 12, and a plurality of battery cells 13. The frame 11 is heat conductive, and has a peripheral wall 111 and a receiving cavity 112 which is closed in the circumference but open at both ends in the axial direction by the peripheral wall 111; the two end plates 12 are respectively fixedly connected to the two ends of the axial opening of the frame 11, and respectively seal the two ends of the axial opening of the frame 11 to form a sealed space S together with the peripheral wall 111; a plurality of battery cells 13 are received in the sealed space S, and each battery cell 13 has at least one secondary battery 131. The battery module 1 also comprises: a coolant 14, which is received in the sealed space S, contacts the peripheral wall 111 and impregnates each secondary battery 131.

[0068] Compared with the prior art that uses aluminum plates for cooling, in the battery module 1 according to the first aspect of the present invention, multiple battery cells 13 are accommodated in a sealed space S, and the coolant 14 contacts the peripheral wall 111 and impregnates each secondary battery 131, so that the secondary battery 131 is in direct contact with the coolant 14 (that is, the coolant 14 impregnates at least a portion of the outer surface of the secondary battery 131). Therefore, compared with the indirect heat exchange between the secondary battery 131 and the water cooling system in the prior art, the heat dissipation path is short. Due to the fluidity of the coolant 14, the coolant 14 flows below its liquid level and fills all allowed gaps in the sealed space S, which increases the heat conduction path and effectively improves the heat dissipation effect and uniformity of the battery module 1; the circumferentially closed frame 11 surrounded by the peripheral wall 111 can use the entire peripheral wall 111 to dissipate heat, which greatly improves the heat dissipation effect of the battery module 1.

[0069] like Figure 1 and Figure 3As shown, the peripheral wall 111 of the frame 11 is also provided with a first opening 1111 connected to the receiving cavity 112; the battery module 1 also includes: a balancing valve V1, which is connected to the first opening 1111. The balancing valve V1 is used to maintain a constant air pressure in the sealed space S to prevent the battery module 1 from being squeezed by external impact or the secondary battery 13 from expanding during the charge and discharge cycle, resulting in excessive internal air pressure in the battery module 1 and leakage of the coolant 14. Preferably, the balancing valve V1 is a breathing valve. Therefore, the liquid level of the coolant 14 in the sealed space S can be determined according to the air pressure requirement in the sealed space S.

[0070] like Figure 1 , Figure 3 , Figure 7 and Figure 8 As shown, the peripheral wall 111 of the frame body 11 is further provided with a second opening 1112 communicating with the receiving cavity 112 for injecting the coolant 14 and a third opening 1113 for discharging the coolant 14 and the gas in the sealed space S.

[0071] After the second opening 1112 and the third opening 1113 complete their functions, the second opening 1112 and the third opening 1113 may each be provided with a sealing sheet P to block them. Thus, the battery module 1 dissipates heat only through the coolant 14 contained in the receiving cavity 112 and the thermally conductive frame 11. Of course, an external cooling system may be further provided externally to enhance the cooling effect. The battery module 1 also includes: a first one-way valve V2, connected to the second opening 1112; a second one-way valve V3, connected to the third opening 1113, and the second one-way valve V3 is opposite to the first one-way valve V2 in the direction of fluid travel.

[0072] The first one-way valve V2 and the second one-way valve V3 can be arranged in any suitable configuration. Figure 7 and Figure 8 The first one-way valve V2 is used to inject the coolant 14 into the sealed space S and ensure that the coolant 14 does not flow out of the first one-way valve V2, and the second one-way valve V3 is used to discharge the gas in the sealed space S or the excessive coolant 14 injected and ensure that the coolant 14 can only flow out but not in (it should be noted that the first one-way valve V2 and the second one-way valve V3 will be removed after the injection is completed, and the second opening 1112 and the third opening 1113 will also be sealed after the first one-way valve V2 and the second one-way valve V3 are removed, for example, refer to Figure 1, the second opening 1112 and the third opening 1113 are each provided with a sealing piece P to block them. Of course, the first one-way valve V2 and the second one-way valve V3 may not be removed so that the coolant 14 can be extracted and injected again later, and heat can also be dissipated through the second one-way valve V3). Specifically, the first one-way valve V2 has: a first upper chamber V21; a first middle chamber V22, the diameter of the first middle chamber V22 is larger than the diameter of the first upper chamber V21; a first lower chamber V23, which is connected to the first middle chamber V22, has a smaller diameter than the first middle chamber V22, and is connected to the second opening 1112; a first sphere V25, which has a diameter larger than the diameter of the first upper chamber V21, larger than the diameter of the first lower chamber V23 but smaller than the diameter of the first middle chamber V22; a spring V24, which is arranged between the first sphere V25 and the first lower chamber V23, and the outer diameter of the spring V24 is The diameter is larger than the diameter of the first lower chamber V23; wherein, the first sphere V25 is accommodated in the first intermediate chamber V22, and can move upward in the first intermediate chamber V22 under the action of the spring V24 to block the first upper chamber V21 so that the first upper chamber V21 is not connected with the first intermediate chamber V22, and can compress the spring V24 downward and open the first upper chamber V21 under the action of the injected coolant 14 so that the first upper chamber V21 is connected with the first intermediate chamber V22 (ensuring that the coolant 14 can only flow from the first upper chamber V21 and cannot flow out from the first lower chamber V23). The second one-way valve V3 comprises: a first upper channel V31; a second lower channel V32, the diameter of the second lower channel V32 is smaller than that of the first upper channel V31; a second sphere V33, located in the first upper channel V31, the diameter of the second sphere V33 is larger than the diameter of the second lower channel V32 but smaller than the diameter of the first upper channel V31 (thereby ensuring that the coolant 14 can only flow out from the second lower channel V32 but cannot flow into the first upper channel V31). Figure 7 and Figure 8 The first one-way valve V2 and the second one-way valve V3 shown are only an example, and any other known one-way valves may be used.

[0073] The type of the secondary battery 131 is not limited. The secondary battery 131 has various forms. According to the type of the outer shell, the secondary battery 131 can be divided into a pouch type secondary battery and a can type secondary battery. The outer shell of the pouch type secondary battery is made of a laminate sheet including a polymer layer and a metal layer. The outer shell of the can type secondary battery is generally composed of a metal shell and a metal top cover sheet.

[0074] In one embodiment, referring to Figures 4 to 6, each secondary battery 131 is a pouch-type secondary battery; the secondary battery 131 has a main body 1311 , side portions 1312 located at both ends of the main body 1311 , and tabs 1313 extending outward from each side portion 1312 . Each battery cell 13 further includes: two fixing blocks 132, each fixing block 132 is fixed to the side portion 1312 of the secondary battery 131 so that the main body 1311 of the secondary battery 131 of two adjacent battery cells 13 is spaced apart, each fixing block 132 is provided with a positioning groove 1321 penetrating along the axial direction of the frame body 11, and each pole ear 1313 passes through the positioning groove 1321 of each fixing block 132; there is a cooling liquid 14 between the main body 1311 of two adjacent secondary batteries 131, between the main body 1311 adjacent to the peripheral wall 111 and the peripheral wall 111, and between the inner wall surface of each end plate 12 and the fixing blocks 132 of the plurality of battery cells 13 (the portion of the pole ear 1313 exposed from the fixing block 132 is located at this position) (the cooling liquid 14 has a variety of filling conditions, for example, the height of the liquid level of the cooling liquid 14 does not reach the inner top surface of the peripheral wall 111, preferably, as Fig. 9 As shown, the coolant 14 fills all gaps in the sealed space S to achieve sufficient heat conduction). The coolant 14 directly cools the tab 1313, greatly improving the working stability of the tab 1313.

[0075] Each fixing block 132 is an elastic body. Preferably, each fixing block 132 is made of plastic. The fixing block 132 can be formed in a variety of ways, such as Figure 5 As shown, it can be formed in one piece, or it can be formed as Figure 6 The molding method shown is that the parts are formed separately and then connected together.

[0076] In the battery module 1 according to the first aspect of the present invention, in one embodiment, Figure 1 As shown, the pole ears 1313 of the secondary batteries 131 of every two adjacent battery cells 13 are bent towards each other and pressed together (of course, the connection method is not limited to this, and the pole ears 1313 of the secondary batteries 131 of more than two adjacent battery cells 13 may also be bent towards each other and pressed together); the battery module 1 also includes: a plurality of connecting plates 15, which are used to electrically connect the plurality of secondary batteries 131 together, and each side of the arrangement direction of each connecting plate 15 is face-to-face connected (such as welding) to the pole ears 1313 of the secondary batteries 131 of two adjacent battery cells 13 that are bent towards each other and pressed together; two output plates 16, which are used for the output of the plurality of secondary batteries 131, and each output plate 16 is face-to-face connected (such as welding) to the pole ears 1313 of the secondary batteries 131 of two adjacent battery cells 13 that are bent towards each other and pressed together.

[0077] like Figure 1As shown, each output piece 16 has a protrusion 161 protruding outward in the front-rear direction; the two protrusions 161 of the two output pieces 16 seal through one of the two end plates 12 .

[0078] In the battery module 1 according to the first aspect of the present invention, in order to position the plurality of battery cells 13 arranged side by side together, in one embodiment, as shown in FIG. Figures 4 to 6 As shown, the fixing block 132 is further provided with: at least one positioning protrusion 1322, located on one side of the fixing block 132 along the parallel direction of the battery cells 13; at least one positioning recess 1323, each positioning recess 1323 corresponds to a positioning protrusion 1322 and is located on the other side of the fixing block 132 along the parallel direction of the battery cells 13; wherein each positioning protrusion 1322 of the fixing block 132 at one end of each battery cell 13 is docked with a corresponding positioning recess 1323 of the fixing block 132 at one end of the adjacent battery cell 13, so as to position two adjacent battery cells 13 together. Of course, other fixing methods can also be used, and are not limited to the above embodiments.

[0079] like Figure 1 As shown, the battery module 1 further includes: a plurality of elastic buffer pads 17, which are located between the two fixing blocks 132 of two adjacent battery cells 13 and between the fixing blocks 132 of each battery cell 13 located at the outermost side by side direction among the plurality of battery cells 13 and the peripheral wall 111 of the frame 11. The arrangement of the plurality of elastic buffer pads 17 allows a gap to exist between each battery cell 13 located at the outermost side by side direction and the peripheral wall 111 of the frame 11, thereby ensuring that each battery cell 13 located at the outermost side by side direction is in contact with the coolant 14. The elastic buffer pads 17 may be foamed silica gel, which will not react with the coolant 14 using thermal oil in the battery module 1, and the permeability of the internal structure of the foamed silica gel can accommodate a large amount of coolant 14 so that the coolant 14 is in full contact with the main body 1311 of the plurality of secondary batteries 131, thereby improving the heat dissipation effect of the battery module 1.

[0080] In the battery module 1 according to the first aspect of the present invention, Figure 1 As shown, the end plate 12 includes: a plate body 121; and an insert 122 fixedly disposed on the plate body 121.

[0081] In order to position the end plate 12 and the fixing block 132, in one embodiment, refer to Figure 1 The fixing block 132 is also provided with: at least one groove 1324, located on the side of the fixing block 132 facing the end plate 12; the plate body 121 of the end plate 12 is provided with: at least one protrusion 1211, located on the side of the end plate 12 facing the multiple fixing blocks 132; each protrusion 1211 of the plate body 121 is docked with a corresponding groove 1324 of the fixing block 132 to position the end plate 12 and the fixing blocks 132 of the multiple battery cells 13 together.

[0082] Each insert 122 has a stop surface 1221 on both sides thereof, and the stop surface 1221 abuts against the axial end surface 1114 of the peripheral wall 111. The edge of the stop surface 1221 is welded to the end surface 1114 of the peripheral wall 111 of the frame 11.

[0083] Each insert 122 has a protrusion 1222 extending toward the receiving cavity 112 on both sides. The protrusion 1222 is located between the outermost fixing block 132 in the parallel direction and the peripheral wall 111 of the frame 11 and is attached to the side surface of the outermost fixing block 132 in the parallel direction.

[0084] In order to make the end plate 12 and the frame 11 sealed, Figure 1 As shown, the battery module 1 further includes: a sealing ring 18 disposed between the periphery of the end plate 12 and the inner surface of the peripheral wall 111 of the frame 11 to form a seal between the inner surface of the peripheral wall 111 of the frame 11 and the periphery of each end plate 12 .

[0085] The periphery of the end plate 12 is provided with a receiving recess 1212 for receiving the sealing ring 18 . Specifically, the receiving recess 1212 is provided at the periphery of the plate body 121 .

[0086] In the battery module 1 according to the first aspect of the present invention, the plate 121 is made of plastic, and the insert 122 is made of aluminum. The plate 121 is formed into one piece with the insert 122 by injection molding. The frame 11 is made of aluminum.

[0087] The cooling liquid 14 is an insulating liquid. Preferably, the insulating liquid is heat transfer oil.

[0088] In the battery module 1 according to the first aspect of the present invention, the peripheral wall 111 is composed of an upper wall, a lower wall, and left and right side walls.

[0089] Next, a simple example is given to illustrate the assembly method of the battery module 1.

[0090] The assembly method of the battery module 1 comprises the following steps: connecting the battery cells 13 side by side; arranging the elastic buffer pads 17 between the two fixing blocks 132 of two adjacent battery cells 13 and on the surfaces of the fixing blocks 132 of the battery cells 13 on the outermost sides of the side-by-side direction to form a combination; pressurizing the combination tooling to compress the elastic buffer pads 17, thereby installing the combination into the receiving cavity 112 of the frame 11; correspondingly welding the two end plates 12 to the two ends of the axial opening of the frame 11; installing the first one-way valve V2 and the second one-way valve V3 respectively on the frame 11; On the second opening 1112 and the third opening 1113 of the body 11, the first one-way valve V2 keeps the coolant 14 from entering but not exiting, and the second one-way valve V3 keeps the coolant 14 from exiting but not entering, and the balancing valve V1 is installed on the first opening 1111; the coolant 14 is injected into the first one-way valve V2. When a small amount of liquid flows out of the second one-way valve V3, it indicates that the coolant 14 completely fills the internal space of the battery module 1, and the injection is stopped; the first one-way valve V2 and the second one-way valve V3 are removed, and the second opening 1112 and the third opening 1113 are provided with sealing sheets P and sealed with glue.

[0091] Next, a battery pack according to a second aspect of the present invention will be described.

[0092] like Figures 10 to 19 As shown, a battery pack according to a second aspect of the present invention includes: a lower box body 2 having a bottom wall 21; at least one battery pack row, each battery pack row including at least one battery module 1, each battery module 1 being arranged on the bottom wall 21 of the lower box body 2, each battery module 1 having a shell 19 forming a sealed space S and a plurality of battery cells 13 accommodated in the sealed space S, each battery cell 13 having at least one secondary battery 131; each battery module 1 is associated with at least one sub-cooling liquid flow passage, and the sub-cooling liquid flow passages of the battery modules 1 of each battery pack row form a total cooling liquid flow passage of the battery module row.

[0093] In one embodiment, if Figures 10 to 19 As shown, each battery module 1 is associated with at least one branch flow passage unit U, and each branch flow passage unit U includes: a flow channel U1, which is arranged on the bottom wall 21; a flow hole U2, which is connected to the flow channel U1 and opens above the inner surface of the bottom wall 21; a first connecting hole U3, which is arranged in each shell 19, connecting the sealed space S of each battery module 1 and the flow hole U2; a connecting tube U4; and a second connecting hole U5, which is arranged in each shell 19, connecting the sealed space S of each battery module 1 and the connecting tube U4; wherein, the flow channel U1, the flow hole U2, and the first connecting hole U3 form a flow channel side passage F1, the second connecting hole U5 and the connecting tube U4 form a connecting tube side passage F2, and the flow channel side passage F1, the sealed space S of the battery module 1 and the connecting tube side passage F2 are connected to form a branch coolant flow passage.

[0094] When each battery pack row has only one battery module 1, the sub-cooling liquid flow passages of the battery module 1 form a total coolant flow passage for the battery module row; when each battery pack row has two battery modules 1, the connecting tube side passage F2 of a sub-cooling liquid flow passage of one battery module 1 is connected to the connecting tube side passage F2 of a sub-cooling liquid flow passage of another battery module 1 to form a total coolant flow passage for each battery module row; when each battery pack row has more than three battery modules 1, the connecting tube side passage F2 of a sub-cooling liquid flow passage of the first battery module 1 is connected to the connecting tube side passage F2 of a sub-cooling liquid flow passage of the second battery module 1, the flow channel side passage F1 of a sub-cooling liquid flow passage of the second battery module 1 is connected to the flow channel side passage F1 of a sub-cooling liquid flow passage of the third battery module 1, and so on, to form a total coolant flow passage for each battery module row.

[0095] In the battery pack according to the second aspect of the present invention, each battery module 1 is associated with at least one branch flow path unit U, and the branch flow path unit U forms a branch cooling liquid flow path, and the cooling liquid 14 flows along a total cooling liquid flow path composed of the branch cooling liquid flow paths of each battery module row to directly take away the heat generated by the multiple battery cells 13 in each battery module 1 of each battery module row, thereby effectively improving the heat dissipation effect of the battery pack.

[0096] The flow channel U1 and the flow hole U2 can be formed in a variety of ways. In one embodiment, Fig.14 and Fig.15 As shown, all flow channels U1 and flow holes U2 are directly formed by the bottom wall 21 (for example, they can be directly formed by 3D printing technology).

[0097] In the battery pack according to the second aspect of the present invention, there are many ways to arrange and number the battery modules 1 in the battery pack. In one embodiment, Fig.14 As shown, when each battery row has only one battery module 1, the flow channel U1 of the total coolant flow passage is directly formed by the bottom wall 21; in another embodiment, as shown in FIG. Fig.15 As shown, when each battery pack row has two battery modules 1, the two connecting tube side passages F2 connected together share a connecting tube U4, and the two flow channels U1 of each total coolant flow passage are directly formed by the bottom wall 21; in another embodiment, as shown Fig.11 , Fig.13 as well as Fig.16As shown, when each battery row has more than three battery modules 1, the two flow channel side passages F1 connected together share a flow channel U1, and each shared flow channel U1 and the flow hole U2 connected to each shared flow channel U1 are formed by a hollow block B arranged on the bottom wall 21, and other flow channels U1 except the shared flow channel U1 are directly formed by the bottom wall 21.

[0098] like Fig.10 and Fig.17 As shown, when there is a block B, the bottom wall 21 of the lower box 2 is further provided with a recess R for accommodating the block B. Of course, the shapes of the block B and the recess R are not limited thereto, and may be other shapes and structures.

[0099] In the battery pack according to the second aspect of the present invention, when each battery module row has two or more total coolant flow paths, all the total coolant flow paths are parallel to each other. Fig.13 As shown, Fig.13 There are two battery module rows, each of which has two total coolant flow paths, wherein Fig.13 The cutaway perspective view shows a total coolant flow path. Compared with one total coolant flow path, each battery module row has more than two total coolant flow paths, which can quickly and fully cool each battery module 1 and improve the heat dissipation effect of the battery pack.

[0100] When the battery pack has more than two battery module rows, in one embodiment, preferably, the total cooling liquid flow paths of adjacent battery module rows are not connected. Fig.13 As shown, Fig.13 There are two battery module rows, each of which has two total coolant flow paths, wherein Fig.13 The cutaway perspective view shows a total coolant flow path, and the total coolant flow paths of the two battery module rows are not connected. Compared with the total coolant flow paths described below being connected, the number of battery modules 1 through which the coolant 14 flows is small, the temperature rise of the coolant 14 is lower, and a better cooling effect is achieved.

[0101] When the battery pack has more than two battery module rows, in another embodiment, refer to Fig.17 , the total coolant flow passages of adjacent battery module rows are connected.

[0102] like Figures 13 to 16 As shown, the battery pack also includes: a plurality of connectors 3, which are connected between the flow hole U2 and the first connecting hole U3 and between one end of the connecting tube U4 and the second connecting hole U5. The arrangement of the connectors 3 enables a sealed connection between the flow hole U2 and the first connecting hole U3 and between one end of the connecting tube U4 and the second connecting hole U5 to prevent liquid exposure.

[0103] The cooling method of the battery pack is suitable for the enclosed space S formed in any manner. In one embodiment, the housing 19 is composed of the frame 11 and the two end plates 12. Of course, the enclosed space S can be formed by the housing 19, for example Fig.18 and Fig.19 As shown, the housing 19 is composed of an upper housing 191 and a lower housing 192 .

[0104] In the battery pack according to the second aspect of the present invention, the secondary battery 131 in each battery module 1 in the battery pack can be a can type secondary battery or a pouch type secondary battery. In one embodiment, the secondary battery 131 is a can type secondary battery, and each can type secondary battery directly constitutes a battery unit 13.

[0105] In another embodiment, the secondary battery 131 is a pouch-type secondary battery, the secondary battery 131 has a main body 1311, side portions 1312 located at both ends of the main body 1311, and pole ears 1313 extending outward from each side portion 1312; each battery cell 13 also includes: two fixing blocks 132, each fixing block 132 is fixed to the side portion 1312 of the secondary battery 131 so that the main body 1311 of the secondary battery 131 of two adjacent battery cells 13 are separated, each fixing block 132 is provided with a positioning groove 1321 extending axially through the shell 19, and each pole ear 1313 passes through the positioning groove 1321 of each fixing block 132.

[0106] Preferably, the housing 19 is heat-conducting, so that in addition to the above-mentioned flowing coolant for cooling, heat can also be dissipated by the housing 19 itself. When in use, the housing 19 can be blown.

[0107] Finally, the battery pack according to the third aspect of the present invention is described.

[0108] like Fig. 20 As shown, the battery pack of the third aspect of the present invention comprises: a lower box body 2 having a bottom wall 21, in which a flow channel U1 is provided; at least one battery module 1 according to the first aspect of the present invention is supported on the bottom wall 21 of the lower box body 2. Specifically, the battery pack of the third aspect of the present invention does not adopt Figures 10 to 19 The flow cooling liquid mode is to cancel the connecting pipe U4, and set the flow channel U1 only in the bottom wall 21 and communicate with the outside, so that Figures 1 to 9 Battery module 1, Figures 1 to 9 The battery module 1 conducts the heat generated by the battery to the thermally conductive frame 11 through the internal coolant 14, and then the frame 11 transfers the heat to the other coolant 14 in the flow channel U1 through the bottom wall 21, thereby achieving heat dissipation.

Claims

1. A battery module (1), comprising: The frame (11) is heat conductive and has a peripheral wall (111) and a receiving cavity (112) formed by the peripheral wall (111) and closed in the circumferential direction but open at two axial ends; Two end plates (12) are respectively fixedly connected to the two ends of the axial opening of the frame (11), and respectively seal the two ends of the axial opening of the frame (11) to form a sealed space (S) together with the peripheral wall (111); A plurality of battery cells (13) are housed in a sealed space (S), each battery cell (13) having at least one secondary battery (131); Characterized in that the battery module (1) further comprises: The cooling liquid (14) is contained in the sealed space (S), contacts the peripheral wall (111) and impregnates each secondary battery (131), and the cooling liquid is an insulating liquid.

2. The battery module (1) according to claim 1, characterized in that: The peripheral wall (111) of the frame (11) is also provided with a first opening (1111) communicating with the receiving cavity (112); The battery module (1) also includes: a balancing valve (V1) connected to the first opening (1111).

3. The battery module (1) according to claim 1, characterized in that: The peripheral wall (111) of the frame (11) is also provided with a second opening (1112) connected to the receiving cavity (112) for injecting the cooling liquid (14) and a third opening (1113) for discharging the cooling liquid (14) and the gas in the sealed space (S).

4. The battery module (1) according to claim 3, characterized in that: The second opening (1112) and the third opening (1113) are each provided with a sealing sheet (P) for sealing them.

5. The battery module (1) according to claim 3, characterized in that: The battery module (1) further comprises: a first one-way valve (V2) connected to the second opening (1112); The second one-way valve (V3) is connected to the third opening (1113), and the second one-way valve (V3) and the first one-way valve (V2) are in opposite directions of fluid flow.

6. The battery module (1) according to claim 1, characterized in that: Each secondary battery (131) is a pouch-type secondary battery; Each secondary battery (131) comprises a main body (1311), side parts (1312) located at both ends of the main body (1311), and tabs (1313) extending outward from each side part (1312); Each battery unit (13) further comprises: two fixing blocks (132), each fixing block (132) being fixed to a side portion (1312) of a secondary battery (131) so as to space the main bodies (1311) of the secondary batteries (131) of two adjacent battery units (13), each fixing block (132) being provided with a positioning groove (1321) penetrating along the axial direction of the frame body (11), each pole lug (1313) passing through the positioning groove (1321) of each fixing block (132); There is cooling liquid (14) between the main bodies (1311) of two adjacent secondary batteries (131), between the main body (1311) adjacent to the peripheral wall (111) and the peripheral wall (111), and between the inner wall surface of each end plate (12) and the fixing blocks (132) of the plurality of battery cells (13).

7. The battery module (1) according to claim 6, characterized in that: The battery module (1) further comprises: A plurality of elastic buffer pads (17) are located between two fixing blocks (132) of two adjacent battery cells (13) and between the fixing blocks (132) of each battery cell (13) located at the outermost sides in the parallel direction among the plurality of battery cells (13) and the peripheral wall (111) of the frame (11).

8. The battery module (1) according to claim 6, characterized in that: The fixing block (132) is further provided with: at least one groove (1324) located on a side of the fixing block (132) facing the end plate (12); The plate body (121) of the end plate (12) is provided with: at least one protrusion (1211) located on a side of the end plate (12) facing the plurality of fixing blocks (132); Each protrusion (1211) of the plate body (121) is butted against a corresponding groove (1324) of the fixing block (132) to position the end plate (12) and the fixing blocks (132) of the plurality of battery cells (13) together.

9. The battery module (1) according to claim 7, characterized in that: The cooling liquid (14) is heat-conducting oil, and the elastic buffer pad (17) is foamed silica gel.

10. A battery pack comprising: The lower box body (2) has a bottom wall (21); At least one battery row, each battery row comprising at least one battery module (1) as described in any one of claims 1 to 9, each battery module (1) being arranged on the bottom wall (21) of the lower box body (2), each battery module (1) having a shell (19) forming a sealed space (S) and a plurality of battery cells (13) accommodated in the sealed space (S), each battery cell (13) having at least one secondary battery (131); each battery module (1) being associated with at least one sub-cooling liquid flow passage, and the sub-cooling liquid flow passages of the battery modules (1) of each battery row forming a total cooling liquid flow passage of the battery module row.

11. The battery pack according to claim 10, characterized in that: Each battery module (1) is associated with at least one branch flow path unit (U), and each branch flow path unit (U) comprises: A flow channel (U1) is provided on the bottom wall (21); A flow hole (U2) connected to the flow channel (U1) and opening toward the upper side of the inner surface of the bottom wall (21); A first connecting hole (U3) is provided in each housing (19) and connects the sealed space (S) of each battery module (1) and the flow hole (U2); Connecting pipe (U4); and A second communication hole (U5) is provided in each housing (19) and connects the sealed space (S) of each battery module (1) and the connection pipe (U4); The flow channel (U1), the flow hole (U2), and the first connecting hole (U3) form a flow channel side passage (F1), the second connecting hole (U5) and the connecting tube (U4) form a connecting tube side passage (F2), and the flow channel side passage (F1), the sealed space (S) of the battery module (1), and the connecting tube side passage (F2) are connected to form a cooling liquid flow passage.

12. A battery pack, characterized in that: include: The lower box body (2) has a bottom wall (21), and a flow channel (U1) is provided in the bottom wall (21); At least one battery module according to any one of claims 1 to 9 is supported on the bottom wall (21) of the lower box (2).

Images