US-12620670-B2 - Battery pack and electric vehicle

US12620670B2US 12620670 B2US12620670 B2US 12620670B2US-12620670-B2

Abstract

A battery pack includes a housing, and at least one housing structural beam and multiple electrode core strings electrically connected to one another located in the housing. The housing includes a housing body, including a top plate and a bottom plate arranged opposite to each other in a first direction. The structural beam is located between the top plate and the bottom plate, the at least one structural beam is connected to the top plate and the bottom plate, and divides the interior of the housing into multiple accommodating cavities, and at least one electrode core string is provided in at least one accommodating cavity. A mounting portion is provided on the housing, and the mounting portion is configured to be connected and fixed to an external load. The electrode core string includes multiple electrode core assemblies sequentially disposed in a second direction and connected in series.

Inventors

Huajun Sun
Zhipei Lu
QINGBO PENG
Long Wan
Yan Zhu

Assignees

BYD COMPANY LIMITED

Dates

Publication Date: 20260505
Application Date: 20221024
Priority Date: 20200424

Claims (20)

1 . A battery pack, comprising: a housing, and at least one structural beam and a plurality of electrode core strings electrically connected to one another located in the housing, wherein the housing comprises a housing body, comprising a top plate and a bottom plate arranged opposite to each other in a first direction, wherein the first direction is a height direction of the housing; the structural beam is located between the top plate and the bottom plate, the at least one structural beam is connected to the top plate and the bottom plate, the at least one structural beam divides the interior of the housing into a plurality of accommodating cavities, and at least one electrode core string is provided in at least one accommodating cavity; a mounting portion is provided on the housing, and the mounting portion is configured to be connected and fixed to an external load; and the electrode core string comprises a plurality of electrode core assemblies sequentially disposed in a second direction and connected in series; the electrode core assembly is encapsulated in an encapsulation film; and a length direction of the electrode core string extends in the second direction, wherein the second direction is a width direction of the housing or the second direction is a length direction of the housing, wherein the electrode core assembly comprises an electrode core assembly body, and a first electrode lead-out member and a second electrode lead-out member for current output, wherein the first electrode lead-out member and the second electrode lead-out member are arranged at two opposite sides of the electrode core assembly body in the second direction, and the first electrode lead-out member of one electrode core assembly of two adjacent electrode core assemblies in the electrode core string is electrically connected to the second electrode lead-out member of the other electrode core assembly via a first electrically conductive member; a fixing intermediate ring is arranged between the electrode core assembly bodies of two adjacent electrode core assemblies, wherein the first electrically conductive member is fixed in the fixing intermediate ring; a structural adhesive is filled between the electrode core assembly bodies of two adjacent electrode core assemblies and the fixing intermediate ring; and the fixing intermediate ring comprises a first intermediate ring and a second intermediate ring arranged opposite to each other in a third direction, wherein the first electrically conductive member is located between the first intermediate ring and the second intermediate ring, the first intermediate ring and the second intermediate ring are connected to clamp and fix the first electrically conductive member, and the third direction is different from the first direction and the second direction.
2 . The battery pack according to claim 1 , wherein a plurality of structural beams are provided, the plurality of structural beams are spaced in a third direction, a length of the structural beam extends in the second direction, wherein the third direction is different from the first direction and the second direction; the plurality of structural beams are connected to the top plate and the bottom plate; and the housing body is integrally formed with the structural beam.
3 . The battery pack according to claim 1 , wherein the housing body further comprises a first side frame and a second side frame arranged at two sides of the housing body in a third direction; the second direction is the length direction of the housing, and the third direction is the width direction of the housing; or the second direction is the width direction of the housing, and the third direction is the length direction of the housing.
4 . The battery pack according to claim 3 , further comprising a cavity inside at least one of the first side frame and the second side frame, wherein a strengthening plate is provided in the cavity, and the strengthening plate divides the cavity into a plurality of sub-cavities.
5 . The battery pack according to claim 4 , wherein the first side frame and the second side frame are provided with a mounting portion.
6 . The battery pack according to claim 1 , wherein the housing body is provided with a first opening at two ends in the second direction and an end plate; the end plate comprises a third side frame and a fourth side frame, and the third side frame and the fourth side frame are sealingly connected to the housing body to close the corresponding first opening.
7 . The battery pack according to claim 6 , wherein the housing body, the third side frame, and the fourth side frame are metal pieces that are sealingly connected by welding.
8 . The battery pack according to claim 7 , further comprising a sealing plate, wherein the accommodating cavity is provided with a second opening at an end in the second direction, the sealing plate is located at an inner side of the end plate, and the sealing plate blocks a part of the second opening adjacent to the bottom plate.
9 . The battery pack according to claim 7 , further comprising a sealing plate, wherein the accommodating cavity is provided with a second opening at an end in the second direction, the sealing plate is located at an inner side of the end plate, and the sealing plate completely blocks off the second opening.
10 . The battery pack according to claim 1 , wherein a length of the electrode core string is greater than 400 mm.
11 . The battery pack according to claim 10 , wherein a plurality of electrode core strings are provided in the accommodating cavity, the plurality of electrode core strings are sequentially arranged and electrically connected in a thickness direction of the electrode core assembly, the thickness direction of the electrode core assembly is parallel to a third direction, the second direction is the length direction of the housing, and the third direction is the width direction of the housing; or the second direction is the width direction of the housing, and the third direction is the length direction of the housing.
12 . The battery pack according to claim 11 , wherein the plurality of electrode core strings in the same accommodating cavity are connected in series, wherein the first electrode core assembly in one electrode core string of two adjacent electrode core strings is electrically connected to the first electrode core assembly in the other electrode core string, and the first electrode lead-out member of the first electrode core assembly in one electrode core string of two adjacent electrode core strings and the second electrode lead-out member of the first electrode core assembly in the other electrode core string are located at the same side; or the last electrode core assembly in one electrode core string of two adjacent electrode core strings is electrically connected to the last electrode core assembly in the other electrode core string, and the second electrode lead-out member of the last electrode core assembly in one electrode core string of two adjacent electrode core strings and the first electrode lead-out member of the last electrode core assembly in the other electrode core string are located at the same side.
13 . The battery pack according to claim 11 , wherein the plurality of electrode core strings in the same accommodating cavity are connected in parallel, wherein the first electrode core assembly in one electrode core string of two adjacent electrode core strings is electrically connected to the first electrode core assembly in the other electrode core string, and the last electrode core assembly in one electrode core string of two adjacent electrode core strings is electrically connected to the last electrode core assembly in the other electrode core string; and the first electrode lead-out member of the first electrode core assembly in one electrode core string of two adjacent electrode core strings and the first electrode lead-out member of the first electrode core assembly in the other electrode core string are located at the same side, and the second electrode lead-out member of the last electrode core assembly in one electrode core string of two adjacent electrode core strings and the second electrode lead-out member of the last electrode core assembly in the other electrode core string are located at the same side.
14 . The battery pack according to any one of claim 11 , wherein the electrode core strings in two adjacent accommodating cavities are connected in series, wherein the first electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the first electrode core assembly of one electrode core string in the other accommodating cavity, and the first electrode lead-out member of the first electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities and the second electrode lead-out member of the first electrode core assembly of one electrode core string in the other accommodating cavity are located at the same side; or the last electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the last electrode core assembly of one electrode core string in the other accommodating cavity, and the first electrode lead-out member of the last electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities and the second electrode lead-out member of the last electrode core assembly of one electrode core string in the other accommodating cavity are located at the same side.
15 . The battery pack according to any one of claim 11 , wherein the electrode core strings in two adjacent accommodating cavities are connected in parallel, wherein the first electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the first electrode core assembly of one electrode core string in the other accommodating cavity, and the last electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the last electrode core assembly of one electrode core string in the other accommodating cavity; or the first electrode lead-out member of the first electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities and the first electrode lead-out member of the first electrode core assembly of one electrode core string in the other accommodating cavity are located at the same side, and the second electrode lead-out member of the last electrode core assembly of one electrode core string in one accommodating cavity of two adjacent accommodating cavities and the second electrode lead-out member of the last electrode core assembly of one electrode core string in the other accommodating cavity are located at the same side.
16 . The battery pack according to claim 1 , wherein one electrode core string is provided in the accommodating cavity; and the electrode core strings in two adjacent accommodating cavities are connected in series or in parallel, wherein when the electrode core strings in two adjacent accommodating cavities are connected in series, the first electrode core assembly of the electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the first electrode core assembly of the electrode core string in the other accommodating cavity, or the last electrode core assembly of the electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the last electrode core assembly of the electrode core string in the other accommodating cavity; and when the electrode core assemblies in two adjacent accommodating cavities are connected in parallel, the first electrode core assembly of the electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the first electrode core assembly of the electrode core string in the other accommodating cavity, or the last electrode core assembly of the electrode core string in one accommodating cavity of two adjacent accommodating cavities is electrically connected to the last electrode core assembly of the electrode core string in the other accommodating cavity.
17 . The battery pack according to claim 1 , wherein the plurality of electrode core assemblies constituting the electrode core string are packaged in the encapsulation film; wherein the connection of the first electrode lead-out member of one electrode core assembly of two serially connected electrode core assemblies with the second electrode lead-out member of the other electrode core assembly is located inside the encapsulation film; and the encapsulation film is formed with an encapsulation portion at a position corresponding to at least one of the first electrode lead-out member and the second electrode lead-out member to isolate two adjacent electrode core assembly bodies.
18 . The battery pack according to claim 1 , wherein each electrode core assembly is encapsulated in one encapsulation film to form an electrode core assembly piece, and the electrode core assembly pieces are serially connected.
19 . The battery pack according to claim 1 , wherein an exhaust orifice is provided on the housing.
20 . The battery pack according to claim 1 , wherein the housing is provided with an adhesive injection hole communicating with the accommodating cavity, each accommodating cavity corresponds to at least one adhesive injection hole, and the adhesive injection hole is configured to fill an adhesive into a corresponding accommodating cavity, to fixedly connect the electrode core assembly and the housing.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation application of PCT Application No. PCT/CN2020/124749 filed on Oct. 29, 2020, which claims priority to Chinese Patent Application No. “202010334642.0” filed by BYD Company Limited on Apr. 24, 2020, and entitled “Battery pack and electric vehicle”, which is incorporated herein by reference in its entirety. FIELD The present disclosure relates to the field of batteries, and specifically to a battery pack and an electric vehicle. BACKGROUND With the continuous popularization of new energy vehicles, the requirements raised for use of power batteries in new energy vehicles are becoming increasingly higher. The traditional battery pack is a battery pack structure formed by mounting a battery module into a battery pack housing. The battery module includes a battery set composed of multiple cells arranged in sequence, side plates arranged at two sides of the battery set and end plates arranged at two ends of the battery set. The side plate and the end plate are connected by a bolt, a tie rod or by welding, to fix the battery set. After the battery module is assembled, it is mounted in the battery pack housing by a fastener such as a bolt. The assembly method where the batteries are assembled into a battery module and then the battery module is mounted in the battery pack housing has the problems of troublesome assembly process, and complex assembly procedure, causing increased manpower and other costs. The structural components of the battery module itself will also cause a heavy weight of the battery pack, thus reducing the utilization of the internal space of the battery pack. SUMMARY The present disclosure proposes a battery pack and an electric vehicle. The battery pack has increased space utilization, reduced weight, and improved energy density. In a first aspect, an embodiment of the present disclosure provides a battery pack, which includes a housing and at least one structural beam, and multiple electrode core strings electrically connected to one another located in the housing. The housing includes a housing body, including a top plate and a bottom plate arranged opposite to each other in a first direction, where the first direction is a height direction of the housing. The structural beam is located between the top plate and the bottom plate. The at least one structural beam is connected to the top plate and the bottom plate, and divides the interior of the housing into multiple accommodating cavities, and at least one electrode core string is provided in at least one accommodating cavity. A mounting portion is provided on the housing, and the mounting portion is configured to be connected and fixed to an external load. The electrode core string includes multiple electrode core assemblies sequentially disposed in a second direction and connected in series. The electrode core assembly is encapsulated in an encapsulation film; and a length direction of the electrode core string extends in the second direction, where the second direction is a width direction of the housing or the second direction is a length direction of the housing. The present disclosure has the following beneficial effects. In the present disclosure, electrode core strings are used, so as to omit the structures fixing the battery casing and the battery module in the related art. This improves the space utilization of the battery pack, reduces the weight of the battery pack, and increases the energy density of the battery pack. Moreover, the structure of the battery pack of the present disclosure is simple, and the assembly efficiency is high, thus reducing the production cost. Furthermore, in the housing of the battery pack according to the present disclosure, the structural beam is located between the top plate and the bottom plate, and the structural beam is connected to the top plate and the bottom plate. Using such a design, the structural beam, the top plate and the bottom plate form an “L”-shaped structure. This structure has high strength and rigidity, to meet the requirements of the housing of the battery pack for load-bearing capacity, impact resistance and extrusion resistance. Moreover, the structure of the housing of the battery pack according to the present disclosure is simple, the production cost is low, and the space utilization rate is high. In addition, the structural beam divides the housing into multiple accommodating cavities. When thermal runaway occurs to a battery core assembly or cell in one of the accommodating cavities, other accommodating cavities will not be affected, thus improving the safety of the battery pack during operation. Furthermore, when this battery pack is mounted on a vehicle, the structural strength of the battery pack provides part of the structural strength of the vehicle, to improve the structural strength of the vehicle, help to meet the design requirement of lightweight of the electric vehicle, and reduce the d