US-12626987-B2 - Buffer member for a battery module, and battery pack and automobile including same

US12626987B2US 12626987 B2US12626987 B2US 12626987B2US-12626987-B2

Abstract

A battery module includes a cover and a battery cell stack in the cover. The battery cell stack includes a plurality of battery cells. The battery module further includes a buffer member in contact with the battery cell stack. The buffer member is configured to communicate fluid in the buffer member.

Inventors

Ho-June Chi
Hang-June CHOI
Jeong-O MUN
Jin-Yong Park

Assignees

LG ENERGY SOLUTION, LTD.

Dates

Publication Date: 20260512
Application Date: 20210823
Priority Date: 20201020

Claims (11)

1 . A battery module comprising: a cover; a battery cell stack in the cover, the battery cell stack comprising a plurality of battery cells; a buffer member in contact with the battery cell stack, wherein the buffer member is configured to communicate fluid in the buffer member, wherein the buffer member comprises: a first sheet; a second sheet coupled to the first sheet; a plurality of fluid buffer layers formed between the first sheet and the second sheet, the plurality of fluid buffer layers being configured to receive the fluid; and a channel formed by directly connecting a first channel to a second channel, the channel connects a first fluid buffer layer of the plurality of fluid buffer layers to two adjacent fluid buffer layers of the plurality of fluid buffer layers, the channel configured to communicate the fluid between the first fluid buffer layer and the two adjacent plurality of fluid buffer layers.
2 . The battery module of claim 1 , wherein the first sheet and the second sheet are film sheets facilitating thermal bonding.
3 . The battery module of claim 1 , further comprising a plurality of channels including the channel, and wherein the plurality of channels connect the plurality of fluid buffer layers.
4 . The battery module of claim 3 , wherein the first channel of the plurality of channels connects the first fluid buffer layer of the plurality of fluid buffer layers to a second fluid buffer layer of the plurality of fluid buffer layers, and wherein the second channel of the plurality of channels connects a third fluid buffer layer of the plurality of fluid buffer layers to the first channel.
5 . The battery module of claim 4 , wherein all of the plurality of fluid buffer layers are communicatively connected to each other through the first channel and the second channel, and wherein a fluid present in one fluid buffer layer of the plurality of fluid buffer layers moves to another fluid buffer layer of the plurality of fluid buffer layer through at least one of the first channel and the second channel when one of the plurality of battery cells swells.
6 . The battery module of claim 4 , wherein a direction of the first channel connected to the second channel is perpendicular to a direction of the second channel.
7 . The battery module of claim 1 , wherein the plurality of fluid buffer layers is formed in a symmetrical shape or an asymmetrical shape between the first sheet and the second sheet.
8 . A battery pack, comprising the battery module according to claim 1 .
9 . A vehicle, comprising the battery module according to claim 1 .
10 . The battery module of claim 1 , wherein a fluid buffer layer is formed of an ellipse shape.
11 . The battery module of claim 1 , wherein at least one channel comprises another second channel directly connected to the first channel, the another second channel connects a fluid buffer layer to a fourth fluid buffer layer of the plurality of fluid buffer layers.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This is a National Phase entry pursuant to 35 U.S.C. 371 of International Application No. PCT/KR2021/011228 filed on Aug. 23, 2021, and claims priority to and the benefit of Korean Patent Application No. 10-2020-0136072 filed on Oct. 20, 2020 in the Republic of Korea, the disclosure of which is incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to a battery module, a battery pack and a vehicle including the same, and more particularly, to a battery module that allows a uniform pressure to be applied to the entire battery cell when swelling occurs in the battery cell, a battery pack, and a vehicle including the same. BACKGROUND ART As technology development of and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Although nickel cadmium batteries or hydrogen ion batteries have been used as secondary batteries of the related art, because the batteries have almost no memory effect compared to nickel-based secondary batteries, recently, lithium secondary batteries that are freely charged and discharged, have very low self-discharge rate, and have high energy density have been widely used. Such a lithium secondary battery mainly uses lithium-based oxides and carbon materials as positive electrode active materials and negative electrode active materials, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate on which a positive electrode active material and a negative electrode active material are respectively coated are arranged with a separator interposed therebetween, and a sheath material, that is, a battery case, that seals and accommodates the electrode assembly together with an electrolyte solution. The lithium secondary battery includes a positive electrode, a negative electrode, a separator interposed therebetween, and an electrolyte, and includes a lithium ion battery (LIB), a polymer lithium ion battery (PLIB), etc. according to which positive electrode active material and negative electrode active material are used. In general, the electrodes of the lithium secondary batteries are formed by coating a positive electrode active material or a negative electrode active material on a current collector such as an aluminum or copper sheet, a mesh, a film, or a foil, and then drying the positive electrode active material or the negative electrode active material. In addition, various types of secondary batteries have a cover capable of protecting a plurality of battery cells, and include a plurality of battery modules in which the plurality of battery cells are stacked and drawn into the cover, and a battery pack including the plurality of battery modules. The battery cells may be electrically connected to each other through a bus bar that is a conductor. In general, a positive electrode lead is manufactured of an aluminum material, a negative electrode lead is manufactured of a copper material, and the bus bar is also manufactured of a copper material. Meanwhile, a swelling phenomenon in which gas is generated inside a battery cell and swells may occur in the battery cell. Referring to Korean Patent Publication No. 10-2020-0106378 which is the related art, the swelling absorption pad 121 is disposed inside the module case or cover 200 to absorb volume expansion due to swelling of the battery cell. However, in the case of the related art, when swelling occurs in a part of the battery cell rather than the entire battery cell, because the swelling absorption pad 121 is pressurized only in the part where swelling occurs, pressure is not uniform in the part of the battery cell where swelling occurs and a part of the battery cell where swelling does not occur, and because local stress is concentrated in the part of the battery cell where swelling occurs, there is a problem in that the battery cell is partially degraded. SUMMARY The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module that prevents stress from being concentrated in a part of a battery cell even when swelling occurs in the battery cell, so that a uniform pressure is applied to the entire battery cell, a battery pack, and a vehicle including the same. In one aspect of the present disclosure, there is provided a battery module including a cover, a battery cell stack in the cover, the battery cell stack comprising a plurality of battery; and a buffer member in contact with the battery cell stack, wherein the buffer member is configured to communicate fluid in the buffer member. The buffer member may include a first sheet; a second sheet coupled to the first sheet; a plurality of fluid buffer layers formed between the first sheet and the second sheet, each of the plurality of fluid buffer layers being configured to received the fluid; an