CN111384327A

CN111384327A - Battery pack

Info

Publication number: CN111384327A
Application number: CN201811642031.1A
Authority: CN
Inventors: 李兴星; 王士源; 吴兴远; 杨海奇; 郑敏捷; 陆泽全
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2020-07-07
Anticipated expiration: 2038-12-29
Also published as: CN111384327B

Abstract

The embodiment of the application provides a battery package, includes: the adjacent unit batteries are electrically connected through the connecting parts; the shell is provided with an inner cavity, and the unit batteries are positioned in the inner cavity of the shell; a top assembly positioned above the unit cells; the cooling system comprises a sealing part, the sealing part is positioned above the unit batteries, and the sealing part and the shell enclose a first cooling flow channel; wherein the first cooling flow channel is used for cooling the top assembly and/or the first cooling flow channel is used for cooling the connection. The first cooling flow channel of the cooling system is disposed above the unit cells, and thus, can be used to cool the top assembly and/or the connection part of the battery pack, improving the performance of the battery pack. Simultaneously, this first cooling runner encloses through casing and sealing member, can the space of rational utilization battery package top, and sets up this first cooling runner after, and is less to the weight increase of this battery package to make this battery package have higher energy density.

Description

Battery pack

[ technical field ] A method for producing a semiconductor device

The application relates to the technical field of energy storage devices, in particular to a battery pack.

[ background of the invention ]

With the development of power batteries, the energy density of the batteries is continuously increased, and the increase of the energy density causes the problem that the heat productivity of the batteries is increased, so that the requirement on the cooling efficiency of a battery cooling system is stricter and stricter. At present, the cooling of battery is mainly realized through pasting the water-cooling board at electric core, and this mode can only be to the surface or the side cooling that electric core pasted the water-cooling board, and cooling efficiency is lower to water-cooling board and battery contact that can not be fine also can't be to the cooling of the parts that generate heat (for example busbar etc.) that are located the battery package top simultaneously, can't satisfy high energy density power battery's cooling demand.

[ application contents ]

In view of the above, embodiments of the present disclosure provide a battery pack to solve the problem that the heat generating components on the top of the battery pack cannot be cooled in the prior art.

The embodiment of the application provides a battery package, includes:

the adjacent unit batteries are electrically connected through the connecting parts;

a housing having an inner cavity, the unit cells being located in the inner cavity of the housing;

a top assembly positioned above the unit cells;

a cooling system including a sealing member positioned above the unit cells and enclosing a first cooling flow channel with the case;

wherein the first cooling flow channel is used for cooling the top assembly and/or the first cooling flow channel is used for cooling the connection portion.

Preferably, the cooling system comprises a plurality of the first cooling flow passages, and the adjacent first cooling flow passages are communicated.

Preferably, the part of the housing above the unit cells is provided with a plurality of grooves, and the grooves are recessed towards the outside of the battery pack;

a rib is arranged between every two adjacent grooves and protrudes towards the inner side of the battery pack;

the grooves form the first cooling flow passage;

the sealing component comprises a plurality of sealing strips, and the convex ribs are compressed correspondingly to the sealing strips.

Preferably, the groove extends along a length direction L of the battery pack;

the cooling system further comprises a first communicating flow channel and a second communicating flow channel, wherein the first communicating flow channel and the second communicating flow channel are respectively arranged at two ends of the first cooling flow channel along the length direction L;

and the adjacent first cooling flow channels are communicated through the first communicating flow channel or the second communicating flow channel.

Preferably, the battery pack further comprises a first end plate and a second end plate, and the second end plate and the first end plate are respectively located at two ends of the battery pack along the length direction L;

the first communicating flow channel is arranged on the first end plate, and the second communicating flow channel is arranged on the second end plate.

Preferably, the first end plate is provided with one or more first stoppers, and the first end plate is further provided with one or more first connecting grooves;

the second end plate is provided with one or more second stop blocks, and the second end plate is also provided with one or more second communication grooves;

the first communicating groove and the second communicating groove are arranged in a staggered mode along the width direction W of the battery pack;

the first communicating groove forms the first communicating flow passage, and the second communicating groove forms the second communicating flow passage;

and the two end parts of the sealing strip are respectively abutted against the corresponding first stop dog and the second stop dog.

Preferably, the shell is provided with a liquid inlet and a liquid outlet, and the bottom of the shell is provided with a cooling medium;

the cooling system further comprises a first flow guiding channel and a second flow guiding channel, wherein the first flow guiding channel is used for guiding a cooling medium into the first cooling channel, and the first flow guiding channel is used for guiding the cooling medium out of the first cooling channel;

the first flow guiding channel extends to the position of the cooling medium at the bottom of the shell.

Preferably, the liquid inlet and the liquid outlet are arranged at one end of the shell along the length direction L;

the battery pack further comprises a first end plate, and the first end plate is arranged at one end close to the liquid inlet;

the first end plate is provided with a first notch and a second notch, the first notch forms the first drainage flow channel, and the second notch forms the second drainage flow channel.

Preferably, the cooling flow channel further includes a second cooling flow channel located at the bottom of the case, the second cooling flow channel being used to cool the unit cells.

Preferably, the battery pack includes a plurality of the unit cells, each of the unit cells being distributed along a length direction L of the battery pack;

gaps are formed between the adjacent unit cells along the length direction L, and the gaps form the second cooling flow channels;

the second cooling flow channel extends in the width direction W of the battery pack.

Preferably, the cooling system further comprises a flow dividing device having a flow dividing channel extending in the length direction L;

the flow dividing device is provided with a fluid inlet which is communicated with the liquid inlet of the shell;

along length direction L, diverging device is provided with a plurality of diffluent mouths, the diffluent mouth with the reposition of redundant personnel runner is linked together, and each the diffluent mouth respectively with second cooling channel aligns.

Preferably, the cooling system further comprises a flow collecting device arranged opposite to the flow dividing device along the width direction W;

the current collecting device is provided with a current collecting flow channel, and the current collecting flow channel extends along the length direction L;

the collecting flow channel is provided with a fluid outlet which is communicated with the liquid outlet of the shell;

along the length direction L, the flow collecting device is provided with a plurality of flow collecting ports, the flow collecting ports are communicated with the flow collecting channels, and the flow collecting ports are aligned with the second cooling channels respectively.

Preferably, the flow area of the flow dividing channel is gradually reduced along the flow direction L of the fluid;

the flow area of each flow dividing port gradually decreases along the flow direction L of the fluid.

Preferably, at the position of the fluid inlet, the flow dividing channel is provided with one or more flow disturbing parts.

Preferably, the cooling system comprises a first flow guiding channel and a second flow guiding channel, the first flow guiding channel is used for guiding the cooling medium into the first cooling channel, and the first flow guiding channel is used for guiding the cooling medium out of the first cooling channel;

the first drainage flow channel is communicated to the fluid inlet of the flow dividing device;

the second drainage flow passage is communicated to the fluid outlet of the collecting device.

Preferably, the unit cell is provided with a post and a top cover plate;

the top assembly comprises one or more of a pole and a top cover plate.

In the present application, the first cooling flow channel of the cooling system is disposed above the unit cells, and thus, can be used to cool the top assembly and/or the connection part of the battery pack, thereby improving the performance of the battery pack. Simultaneously, this first cooling runner encloses through casing and sealing member, can the space of rational utilization battery package top, and sets up this first cooling runner after, and is less to the weight increase of this battery package to make this battery package have higher energy density.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a battery pack provided in the present application in one embodiment;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a schematic structural view of the upper cover and the sealing member of FIG. 2;

FIG. 4 is a schematic view of the structure of FIG. 1 with the upper cover removed;

FIG. 5 is an enlarged view of a portion I of FIG. 1;

FIG. 6 is an enlarged view of a portion II of FIG. 4;

FIG. 7 is a schematic view of the structure of the flow divider of FIG. 2;

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a side view of FIG. 7;

fig. 10 is a schematic structural view of the current collecting device of fig. 2;

FIG. 11 is a schematic view of the first end plate of FIG. 2;

FIG. 12 is a schematic view of the second end plate of FIG. 2;

fig. 13 is a schematic view of a cooling flow channel of a cooling system in a battery pack provided herein;

FIG. 14 is an enlarged view of a portion III of FIG. 13;

FIG. 15 is an enlarged view of a portion IV of FIG. 13;

fig. 16 is a partial enlarged view of the portion v in fig. 13.

Reference numerals:

1-a shell;

11-upper cover;

111-grooves;

112-ribs;

12-a lower shell;

2-a cooling system;

21-a cooling flow channel;

211-a first cooling flow channel;

212-a second cooling flow channel;

213-a flow dividing channel;

214-a collecting flow channel;

215-a first drainage flow channel;

216-a second drainage flow channel;

217-a first communicating flow channel;

218-a second communicating flow path; 22-a flow splitting device;

221-a first body portion;

222-a fluid inlet;

223-a shunt port;

224-a first spoiler; 23-a current collecting device;

231-a second body portion;

232-a fluid outlet;

233-collecting port;

24-a first end plate;

241-a first notch;

242-a second gap;

243-first stop;

244-a first connecting channel; 25-a second end plate;

251-a second stop;

252-a second communication channel; 26-a sealing member;

261-sealing strip;

262-a sealing frame;

3-a unit cell;

31-a connecting portion;

32-gap.

[ detailed description ] embodiments

For better understanding of the technical solutions of the present application, the following detailed descriptions of the embodiments of the present application are provided with reference to the accompanying drawings.

It should be understood that the embodiments described are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be noted that the terms "upper", "lower", "left", "right", and the like used in the embodiments of the present application are described in terms of the angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In addition, in this context, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on "or" under "the other element or be indirectly on" or "under" the other element via an intermediate element.

Referring to fig. 1 to 16, fig. 1 is a schematic structural diagram of a battery pack in an embodiment of the present disclosure; FIG. 2 is an exploded view of FIG. 1; FIG. 3 is a schematic structural view of the upper cover and the sealing member of FIG. 2; FIG. 4 is a schematic view of the structure of FIG. 1 with the upper cover removed; FIG. 5 is an enlarged view of a portion I of FIG. 1; FIG. 6 is an enlarged view of a portion II of FIG. 4; FIG. 7 is a schematic view of the structure of the flow divider of FIG. 2; FIG. 8 is a front view of FIG. 7; FIG. 9 is a side view of FIG. 7; fig. 10 is a schematic structural view of the current collecting device of fig. 2; FIG. 11 is a schematic view of the first end plate of FIG. 2; FIG. 12 is a schematic view of the second end plate of FIG. 2; fig. 13 is a schematic view of a cooling flow channel of a cooling system in a battery pack provided herein; FIG. 14 is an enlarged view of a portion III of FIG. 13; FIG. 15 is an enlarged view of a portion IV of FIG. 13; fig. 16 is a partial enlarged view of the portion v in fig. 13.

An embodiment of the present application provides a battery pack, as shown in fig. 1 and 2, the battery pack includes: the shell 1, the shell 1 may specifically include an upper cover 11 and a lower shell 12, and the upper cover 11 is connected with the lower shell 12 to enclose an inner cavity of the shell 1; the inner cavity of the case 1 houses the unit cells 3 and also includes a top assembly.

Specifically, the top of the unit battery 3 has a post and top cover structure, and both the post and the top cover are located on the top of the unit battery 3, so the top assembly of the battery pack may include one or more of the post and the top cover. Meanwhile, adjacent unit cells 3 are electrically connected by a connection part 31 (the connection part may be a buss bar), and the connection part 31 is also located at the top of the unit cell 3. When the unit cell 3 is operated, the above-mentioned post, top cover plate and connecting portion 31 all generate heat, and when the amount of heat generation is too large, the normal operation of the unit cell 3 is affected. In the present application, a cooling system is added to the battery pack, which can be used to cool the top assembly and/or the connection portion 31.

It should be noted that fig. 13 shows the cooling flow passage 21 of the cooling system 2, which is a profile formed when the cooling medium flows in the cooling system 2, and is not a component included in the cooling system 2, and in the cooling flow passage 21, the cooling medium flows in the direction of the arrow in fig. 13. The cooling flow passage 21 is formed as described below.

As shown in fig. 2 and 13, the cooling system 2 includes a sealing member 26, the sealing member 26 is located above the unit cells 3, the sealing member 26 and the upper cover 11 of the case 1 enclose a first cooling flow channel 211, a cooling medium can flow in the first cooling flow channel 211, and the first cooling flow channel 211 is used for cooling the top assembly and/or the connection portion 31.

In the present application, the first cooling channel 211 of the cooling system 2 is disposed above the unit cells 3, and thus, can be used to cool the top assembly and/or the connection part 31 of the battery pack, thereby improving the performance of the battery pack. Meanwhile, the first cooling flow channel 211 is enclosed by the casing 1 and the sealing part 26, so that the space above the battery pack can be reasonably utilized, and the weight of the battery pack is slightly increased after the first cooling flow channel 211 is arranged, so that the battery pack has higher energy density.

Further, as shown in fig. 13, the cooling flow channel 21 includes a plurality of first cooling flow channels 211, and adjacent first cooling flow channels 211 are communicated with each other.

In this embodiment, the plurality of cooling channels 211 that are communicated with each other are provided, which facilitates the realization of the directional flow of the cooling medium, thereby improving the cooling effect.

Specifically, as shown in fig. 3, in the case 1, a portion located above the unit cells 3 is an upper cover 11, and the upper cover 11 is provided with a plurality of grooves 111, wherein each groove 111 is recessed toward the outside of the pack, each groove 111 is recessed upward in the height direction H based on the viewing angle shown in fig. 2, and at the same time, a rib 112 is provided between adjacent grooves 222, the rib 112 is raised toward the inside of the pack, and each rib is raised downward in the height direction H based on the viewing angle shown in fig. 2. Therefore, in the upper cover 11, the grooves 111 and the ribs 112 are opposite to each other, and the ribs 112 serve as boundaries between adjacent grooves 111.

Based on the above structure, after the upper cover 11 is provided with the groove 111, the second bottom wall of the groove 111 has a certain distance from the unit cell 3 along the height direction H, and the space occupied by the distance forms the first cooling flow channel 211. Meanwhile, as shown in fig. 3, the sealing member 26 includes a plurality of sealing strips 261, and each sealing strip 261 is disposed to correspond to the rib 112, so that the rib 112 can be pressed against the sealing strip 261 when the upper cover 11 is coupled to the lower cover 12.

In this embodiment, after the rib 112 of the upper cover 11 is pressed against the sealing strip 261, the adjacent first cooling flow channels 211 can be sealed, so that the cooling medium flows along each first cooling flow channel 211, and the cooling flow channels 211 can pass through the top assembly and/or the connecting portion to achieve cooling.

Meanwhile, the sealing member 26 further includes a sealing frame 262, and the sealing frame 262 serves to seal both when the upper cover 11 is coupled to the lower case 12, so as to form a closed inner cavity of the battery pack. In addition, the sealing frame 262 may also be used to surround the first cooling flow channel 211, except for sealing the inner cavity of the battery pack, and when the upper cover 11 and the lower cover 12 press the sealing frame 262, the sealing frame 262 may surround the first cooling flow channel 211 at the end.

Further, as shown in fig. 13, each of the grooves 111 and the ribs 112 extends in the length direction L of the battery pack, and thus, the first cooling flow channels 211 extend in the length direction L of the battery pack. Meanwhile, the cooling flow channel 21 further includes a first communicating flow channel 217 and a second communicating flow channel 218, the first communicating flow channel 217 and the second communicating flow channel 218 are used for connecting the adjacent first cooling flow channels 211 end to end, that is, the first cooling flow channels 211 can be connected in series through the first communicating flow channel 217 and the second communicating flow channel 218, and the cooling medium can bypass along the first cooling flow channel 211, the first cooling flow channel 217 and the second cooling flow channel 218.

Specifically, as shown in fig. 13 to 15, the first communicating flow channel 217 and the second communicating flow channel 218 are respectively disposed at two ends of the first cooling flow channel 212 along the length direction L; adjacent second cooling channels 212 are in communication via a first communication channel 217 or a second communication channel 218, for example, when a first cooling channel 212 is in communication with a second first cooling channel 212 via the first communication channel 217, the second first cooling channel 212 is in communication with a third first cooling channel 212 via the second communication channel 218, and so on.

More specifically, as shown in fig. 2 and 4, the battery pack further includes a first end plate 24 and a second end plate 25, and the second end plate 25 and the first end plate 24 are respectively located at both ends of the battery pack in the length direction L, and the first end plate 24 and the second end plate 25 both extend in the width direction W of the battery pack. Meanwhile, as shown in fig. 5 and 14, the first communication flow path 217 is provided at the upper end of the first end plate 24, and as shown in fig. 6 and 15, the second communication flow path 218 is provided at the upper end of the second end plate 25.

As shown in fig. 5 and 11, one or more first stoppers 243 and one or more first connecting grooves 244 are disposed at the upper end of the first end plate 24, and adjacent first connecting grooves 244 are separated from each other by the first stoppers 243, and the first connecting grooves 244 form the first connecting flow channel 217; as shown in fig. 6 and 12, the second end plate 25 is provided with one or more second stoppers 251 and one or more second communication grooves 252, and adjacent second communication grooves 252 are isolated from each other by the second stoppers 251, and the second communication grooves 252 form the second communication flow path 218.

Since the first connecting groove 244 and the second connecting groove 245 connect different and adjacent first cooling flow passages 211, respectively, the first connecting groove 244 and the second connecting groove 252 are disposed to be staggered from each other in the width direction W of the battery pack; in the sealing member 26, when both ends of the sealing tape 261 abut against the corresponding first stopper 243 and second stopper 251, respectively, and the sealing tape 261 abuts against the first stopper 243 or second stopper 251, the coolant can be prevented from flowing from the stopper position to the adjacent first cooling flow passage 211.

In the above embodiments, the flow channel located above the battery pack in the cooling system 2 may be provided with a cooling medium inlet and a cooling medium outlet to realize circulation of the cooling medium above the battery pack, and specifically, the first cooling flow channel 211 and/or the communication flow channel may be provided with a cooling medium inlet, and the first cooling flow channel 211 and/or the communication flow channel may be provided with a cooling medium outlet.

Of course, the flow channels above the battery pack in the above embodiments may also share the cooling medium inlet and the cooling medium outlet with the flow channels at other positions in the battery pack, and the specific structure is described below.

Further, this casing 1 is provided with inlet and liquid outlet, and wherein, this inlet is used for letting in cooling medium in cooling runner 21, and the liquid outlet is used for the cooling medium after the heat transfer of discharging in cooling runner 21, and after cooling medium let in casing 1, the bottom of its inner chamber has cooling medium. Meanwhile, as shown in fig. 13 and 14, the cooling flow channel 21 further includes a first flow guiding channel 215 and a second flow guiding channel 216, the first flow guiding channel 215 is used for guiding the cooling medium from the bottom of the battery pack cavity to the first cooling flow channel 211, the first flow guiding channel 215 is used for guiding the cooling medium in the first cooling flow channel 211 out of the first cooling flow channel 211, and therefore, the first flow guiding channel 215 extends to the cooling medium position at the bottom of the housing 1.

Therefore, in this embodiment, by providing the first drainage flow channel 215 and the second drainage flow channel 216, the flow channel located above the battery pack and the flow channel located at the bottom of the battery pack share the liquid inlet and the liquid outlet, so that the components of the battery pack can be saved, and the energy density can be improved.

Specifically, the liquid inlet and the liquid outlet are disposed at an end of the housing 1 along the length direction L, and the end plate is disposed at an end of the battery pack close to the liquid inlet and the liquid outlet, and in the first end plate 24, the first drainage flow channel 215 and the second drainage flow channel 216 are disposed besides the first communication flow channel 217 for communicating the adjacent first cooling flow channels 211.

More specifically, as shown in fig. 11, the first end plate 24 is provided with a first notch 241 and a second notch 242, the first notch 241 is communicated to the first communicating groove 244 or the first cooling flow passage 211, and in the embodiment shown in fig. 5, the first notch 241 is communicated to the first cooling flow passage 211, so that the first notch 241 forms the first flow guiding flow passage 215; meanwhile, the second notch 242 is connected to the first connecting groove 244 or the first cooling channel 211, and in the embodiment shown in fig. 6, the second notch 242 is connected to the first cooling channel 211, so that the second notch 242 forms the second drainage channel 216.

In the above embodiments, as shown in fig. 13, the cooling flow channel 21 of the battery pack further includes the second cooling flow channel 212 disposed at the bottom of the battery pack, so that the second cooling flow channel 212 is used for cooling the bottom, the side and the end of the unit cell 3. The first cooling flow channel 211 and the second cooling flow channel 212 are communicated with each other through a first diversion flow channel 215 and a second diversion flow channel 216.

Specifically, as shown in fig. 4 to 6, in the battery pack, each unit cell 3 is stacked in the inner cavity of the battery pack along the length direction L, and after stacking, gaps 32 are formed between adjacent unit cells 3 along the length direction L, and each gap 32 forms the second cooling flow channel 212, as shown in fig. 13 and 16, each second cooling flow channel 212 extends along the width direction W of the battery pack. When the cooling medium flows through the second cooling flow channel 212, the large surface of the unit cell 3 can be cooled.

Therefore, in the present application, as shown in fig. 13, the cooling flow channels 21 of the battery pack include the first cooling flow channels 211 located above the battery pack and the second cooling flow channels 212 located between the battery packs, so that not only the large surfaces of the unit cells 3 can be cooled, but also the top members and/or the connection parts 31 above the unit cells 3 can be cooled, thereby enabling the cooling system 2 to have a good cooling effect.

Further, as shown in fig. 2, the cooling system 2 further includes a flow dividing device 22, the flow dividing device 22 is located at one end of the liquid inlet of the housing 1, and the flow dividing device 22 has a flow dividing channel 213, as shown in fig. 13, the flow dividing channel 213 extends along the length direction L, as shown in fig. 7, the flow dividing device 22 has a fluid inlet 222, and the fluid inlet 222 is communicated with the liquid inlet of the housing 1, so that the cooling medium can be introduced into the flow dividing channel 213 through the liquid inlet, and the cooling medium flows along the length direction L in the flow dividing channel 213. The flow dividing device 22 has a first body 221, and the flow dividing channel 213 is disposed in the first body 221.

Specifically, the flow dividing device 22 is provided with a plurality of flow dividing ports 223 along the longitudinal direction L, and each flow dividing port 223 is provided in the side wall of the flow dividing flow passage 213, so that each flow dividing port 223 communicates with the flow dividing flow passage 213, and at the same time, each flow dividing port 223 is aligned with each second cooling flow passage 212 between the unit cells 3, respectively.

Therefore, in the cooling system 2, the cooling medium can be introduced into the second cooling channels 212 through the flow dividing device 22, and the unit cells 3 can be cooled.

In this embodiment, after the flow dividing device 22 is provided, the fluidity of the cooling medium in the second cooling flow channel 212 can be improved, so that the heat exchange efficiency between the cooling medium and the unit cells 3 is improved, and the cooling effect of the cooling system 2 in the battery pack is further improved.

Further, as shown in fig. 2, the cooling system 2 further includes a collecting device 23, and the collecting device 23 is disposed opposite to the dividing device 22 along the width direction W, that is, the collecting device 23 is located at one end of the liquid outlet of the housing 1. Specifically, the collecting device 23 has a collecting flow channel 214, as shown in fig. 13, the collecting flow channel 214 extends along the length direction L, as shown in fig. 10, the collecting device 23 has a fluid outlet 232, and the fluid outlet 232 is communicated with the liquid outlet of the housing 1, so that the cooling medium in the collecting flow channel 214 can be discharged through the liquid outlet, and the cooling medium flows along the length direction L in the collecting flow channel 214. The current collecting device 214 has a second body 23, and the current collecting channel 214 is disposed on the second body 23.

Specifically, the current collecting device 23 is provided with a plurality of current collecting ports 233 along the longitudinal direction L, and the current collecting ports 233 are provided on the side walls of the current collecting flow channels 214, respectively, so that the current collecting ports 233 communicate with the current collecting flow channels 214, and the current collecting ports 233 are aligned with the second cooling flow channels 212 between the unit cells 3, respectively.

Therefore, in the cooling system 2, the cooling medium in the second cooling flow channel 212 after exchanging heat with the unit cells 3 can enter the collecting flow channel 214 of the collecting device 23 and be discharged from the liquid outlet of the housing 1.

In this embodiment, at the bottom of the battery pack, as indicated by arrows in fig. 13, the cooling medium flows in the flow dividing channel 213 through the fluid inlet and then flows in the longitudinal direction L, and at the same time, the cooling medium also flows in the width direction W and enters the second cooling channel 212 through the flow dividing port 223, flows in the second cooling channel 212 in the width direction W, then enters the current collecting channel 214 through the current collecting port 233, and flows in the current collecting channel 214 in the longitudinal direction L.

Further, since the flow areas of the flow dividing channel 213, the flow dividing port 223, the second cooling channel 212, the flow collecting port 233, and the flow collecting channel 214 are different, and the area of the flow dividing channel 213 is larger than the areas of the flow dividing port 223 and the second cooling channel 212, the flow velocity of the cooling medium increases in the process of flowing from the flow dividing channel 213 to the flow dividing port 223 and the second cooling channel 212, thereby improving the fluidity of the cooling medium.

As shown in fig. 7 to 9, when the cooling medium enters the branch flow channel 213 from the fluid inlet 222, the flow velocity of the cooling medium is small at the position of the fluid inlet 222, and the flow velocity of the cooling medium is large at the position away from the fluid inlet 222, that is, the flow velocity thereof gradually increases along the flow direction L of the cooling medium. In order to improve the uniformity of the flow rate of the cooling medium entering each of the second cooling channels 212, it is possible to improve the uniformity of the flow rate of the cooling medium in the branch channels 213.

Specifically, in the present embodiment, the flow area of the branch flow channel 213 is gradually reduced along the flow direction L of the cooling medium, and at the same time, the flow velocity of the cooling medium is gradually increased along the flow direction L of the cooling medium, so that the flow rate of the cooling medium is more uniform along the flow direction L by changing the flow area of the branch flow channel 213, thereby improving the flow rate uniformity of the cooling medium in each second cooling flow channel 212.

Meanwhile, since the cooling medium enters the second cooling flow channel 212 from the flow dividing flow channel 213 through the flow dividing ports 223, the uniformity of the flow rate of the cooling medium in the second cooling flow channel 212 can be improved by changing the flow area of each flow dividing port 223.

Specifically, the flow area of each flow dividing port 223 gradually decreases in the flow direction L of the fluid, and the flow velocity of the cooling medium gradually increases in the flow direction L of the cooling medium, so that the flow rate of the cooling medium discharged along each flow dividing port 223 is made more uniform by changing the flow area of the flow dividing port 223, thereby further improving the flow uniformity of the cooling medium in each second cooling flow passage 212.

More specifically, since the respective flow dividing openings 223 are aligned with the respective second cooling flow passages 212 and the sectional area of the second cooling flow passages 212 is small, the dimension of the respective flow dividing openings 223 in the longitudinal direction L is small, and in order to increase the flow rate, as shown in fig. 7 to 9, in the flow dividing device 22, the respective flow dividing openings 223 extend in the height direction H, that is, the dimension in the height direction H is large. And in order to improve the flow uniformity of the second cooling flow passage 212, the size of each flow dividing port 223 in the height direction H is gradually reduced along the flow direction L of the fluid.

On the other hand, as shown in fig. 7, in the flow dividing channel 213, at the position of the fluid inlet 222, the flow dividing channel 213 is provided with one or more first spoiler portions 224, and when one first spoiler portion 224 is provided, the cooling medium can flow between the side wall of the flow dividing channel 213 and the first spoiler portion 224; when a plurality of first spoiler portions 224 are provided, the cooling medium can flow between the adjacent first spoiler portions 224, and/or the cooling medium can flow between the first spoiler portions 224 and the side walls of the flow dividing channel 213.

In this embodiment, after the first spoiler 224 is disposed in the flow dividing channel 213, and the first spoiler 224 is located at the fluid inlet 222, the turbulence degree of the cooling medium at the fluid inlet 222 can be increased, so as to increase the flow velocity of the cooling medium at the fluid inlet 222, further increase the flow rate of the cooling medium entering the second cooling channel 212 from the flow dividing port 223 at the position, and further increase the uniformity of the flow rate of each second cooling channel 212.

More specifically, the flow dividing channel 213 includes a first sidewall and a second sidewall that are opposite to each other, when the flow dividing channel includes a first spoiler 224, the first spoiler 224 is fixed to the first sidewall and/or the second sidewall, and when one end of the first spoiler 224 is fixed to the first sidewall and the other end of the first spoiler 224 is fixed to the second sidewall, the first spoiler 224 can support the two sidewalls of the flow dividing channel 213.

When a plurality of first spoiler portions 224 are disposed in the flow dividing channel 213, one of the adjacent first spoiler portions 224 is fixed to the first sidewall and the other is fixed to the second sidewall, or one end of each first spoiler portion 224 is fixed to the first sidewall and the other end is fixed to the second sidewall.

Similarly, when the first spoiler 224 is fixed to both the first sidewall and the second sidewall, the structural strength of the flow dividing device 22 can be improved.

On the other hand, as shown in fig. 7, the first spoiler portions 224 are distributed along the height direction H, and a predetermined distance is provided between adjacent first spoiler portions, and the cooling medium can flow from a space occupied by the predetermined distance. And the preset distances between the adjacent first spoiler portions 224 are not exactly the same.

Specifically, in the present embodiment, the first spoiler portion 224 may be a spoiler or a spoiler protrusion, and the specific structure thereof is not limited.

In addition, in the above embodiments, the collecting device 23 includes the second body portion 231, the second body portion 231 is provided with the collecting channel 214, and the side wall of the collecting channel 214 is opened with a plurality of collecting ports 233.

In particular, in this embodiment, the collecting device 23 may also be of the same structure as the dividing device 22.

In the above embodiments, as shown in fig. 13, when the cooling flow channel 21 includes the first cooling flow channel 211, the first communicating flow channel 217, the second communicating flow channel 218, the first flow-guiding flow channel 215, the second flow-guiding flow channel 216, the second cooling flow channel 212, the flow-dividing flow channel 213, and the flow-collecting flow channel 214, the first flow-guiding flow channel 215 may be connected to the fluid inlet 222 of the flow-dividing device 22, and the second flow-guiding flow channel 216 may be connected to the fluid outlet 232 of the flow-collecting device 23.

The upper flow channel above the battery pack comprises a first cooling flow channel 211, a first communication flow channel 217 and a second communication flow channel 218, and the lower flow channel at the bottom of the battery pack comprises a second cooling flow channel 212, a flow dividing flow channel 213 and a flow collecting flow channel 214. In this embodiment, the upper flow passage and the lower flow passage are connected in parallel through the first flow guiding passage 215 and the second flow guiding passage 216, so that the upper flow passage and the lower flow passage are not affected by each other.

In addition, in the present application, the structure or shape of the upper layer flow channel and/or the lower layer flow channel is changed, so that the cooling medium of the upper layer flow channel and the upper layer flow channel has the best cooling effect.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A battery pack, comprising:

a top assembly;

2. The battery pack according to claim 1, wherein the cooling system includes a plurality of the first cooling flow passages, and adjacent ones of the first cooling flow passages communicate.

3. The battery pack according to claim 2, wherein a portion of the case above the unit cells is provided with a plurality of grooves that are recessed in a direction toward an outside of the battery pack;

the grooves form the first cooling flow passage;

4. The battery pack of claim 3, wherein the groove extends in a length direction L of the battery pack;

5. The battery pack according to claim 4, further comprising a first end plate and a second end plate, the second end plate and the first end plate being respectively located at both ends of the battery pack in the length direction L;

6. The battery pack of claim 5, wherein the first end plate is provided with one or more first stops, the first end plate further being provided with one or more first connecting slots;

7. The battery pack according to claim 1, wherein the case is provided with a liquid inlet and a liquid outlet, and a bottom of the case has a cooling medium;

8. The battery pack according to claim 7, wherein the liquid inlet and the liquid outlet are provided at one end of the case in a length direction L;

9. The battery pack according to any one of claims 1 to 8, wherein the cooling flow channel further comprises a second cooling flow channel located at the bottom of the case, the second cooling flow channel being used to cool the unit cells.

10. The battery pack according to claim 9, wherein the battery pack includes a plurality of the unit cells, each of the unit cells being distributed along a length direction L of the battery pack;

11. The battery pack of claim 10, wherein the cooling system further comprises a flow splitting device having a flow splitting flow channel extending along a length direction L;

12. The battery pack according to claim 11, wherein the cooling system further includes a current collecting device disposed opposite to the current dividing device in a width direction W;

13. The battery pack according to claim 11, wherein the flow area of the flow dividing flow passage is gradually reduced in a flow direction L of the fluid;

14. A battery pack, as recited in claim 11, wherein the flow diverter channel is provided with one or more flow disrupters at the location of the fluid inlet.

15. The battery pack of claim 12, wherein the cooling system includes a first flow directing channel for introducing a cooling medium into the first cooling flow channel and a second flow directing channel for directing a cooling medium out of the first cooling flow channel;

16. The battery pack according to any one of claims 1 to 8, wherein the unit cells are provided with a post and a top cover plate;

the top assembly comprises one or more of a pole and a top cover plate.