US-20260128458-A1 - BATTERY PACK

US20260128458A1US 20260128458 A1US20260128458 A1US 20260128458A1US-20260128458-A1

Abstract

A battery pack includes a battery cell that includes a safety valve that opens when internal pressure increases and externally releases gas, an exhaust passage through which gas released from the safety valve flows, a heat insulating member provided to cover the safety valve, and a holding member that holds the heat insulating member, in which an accommodating portion is provided in a wall portion of the exhaust passage at a position facing the heat insulating member, and the heat insulating member provides thermal insulation between the exhaust passage and the battery cell when the safety valve is not opened, and is separated from the holding member and accommodated in the accommodating portion by the gas released from the safety valve when the safety valve is opened, so as to provide thermal insulation between the gas released from the safety valve and the wall portion of the exhaust passage.

Inventors

Osamu Yamashita

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260507
Application Date: 20250917
Priority Date: 20241101

Claims (4)

1 . A battery pack comprising: a battery cell that includes a safety valve that opens when internal pressure increases, and externally releases gas; a battery module in which a plurality of the battery cells is disposed arrayed; a case that accommodates the battery module; an exhaust passage through which gas that is released from the safety valve flows; a heat insulating member that is provided to cover the safety valve, and that faces the exhaust passage; and a holding member that is provided between the battery cells and the case, and that holds the heat insulating member, wherein an accommodating portion is provided in a wall portion of the exhaust passage at a position facing the heat insulating member, and the heat insulating member provides thermal insulation between the exhaust passage and the battery cell when the safety valve is not opened, and is separated from the holding member and accommodated in the accommodating portion by the gas that is released from the safety valve when the safety valve is opened, so as to provide thermal insulation between the gas that is released from the safety valve and the wall portion of the exhaust passage.
2 . The battery pack according to claim 1 , wherein the heat insulating member accommodated in the accommodating portion is interposed between the wall portion of the exhaust passage and the gas while receiving the gas being released from the safety valve, that is opened, toward the accommodating portion.
3 . The battery pack according to claim 2 , wherein, when the safety valve is opened in any one of the battery cells, other battery cells are thermally insulated from the gas in the exhaust passage by the heat insulating members that are held by the holding member.
4 . The battery pack according to claim 3 , further comprising: a shear panel that is disposed downward from the case, wherein the exhaust passage is defined by the case and the shear panel, an exhaust hole that opens into the exhaust passage is provided in a bottom portion of the case, the safety valve is provided on a lower face of the battery cell, the holding member is provided between the lower face of the battery cell and the bottom portion of the case, the heat insulating member faces the exhaust passage through the exhaust hole, and the accommodating portion is provided on the shear panel and includes a plurality of protrusions that protrude toward a battery cell side.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2024-193011 filed on November 1, 2024. The disclosure of the above-identified application, including the specification, drawings, and claims, is incorporated by reference herein in its entirety. BACKGROUND 1.Technical Field The present disclosure relates to a battery pack. 2. Description of Related Art WO 2020/110448 discloses that in a battery pack having an exhaust duct upward from a battery module, an impact absorbing layer is provided on a face of the exhaust duct facing a safety valve of a battery cell, to protect the exhaust duct from high-temperature gas that is released from the safety valve. SUMMARY In a configuration that is described in WO 2020/110448, there is no heat insulating member provided to thermally insulate the battery cells from the gas in the exhaust duct, and accordingly when gas is released from an abnormal battery cell into the exhaust duct, normal cells will be subjected to heat from the gas in the exhaust duct. In this case, there is a concern that normal cells may become excessively hot and start to generate abnormal heat, which may lead to a chain reaction of abnormal heat generation in the battery cells. One conceivable solution is to provide a heat insulating member to thermally insulate the battery cells from the gas inside the exhaust duct. However, adding a heat insulating member to thermally insulate the battery cells from the gas in the exhaust duct to a structure in which a heat insulating member for protecting the exhaust duct is provided, as in the configuration that is described in WO 2020/110448, will raise costs. The present disclosure has been made in consideration of the above-described circumstances, and an object thereof is to provide a battery pack that can protect wall portions of an exhaust passage and the battery cells from high-temperature gas that is released from the battery cells, while suppressing increases in costs. A battery pack according to the present disclosure includes a battery cell that includes a safety valve that opens when internal pressure increases, and externally releases gas, a battery module in which a plurality of the battery cells is disposed arrayed, a case that accommodates the battery module, an exhaust passage through which gas that is released from the safety valve flows, a heat insulating member that is provided to cover the safety valve, and that faces the exhaust passage, and a holding member that is provided between the battery cells and the case, and that holds the heat insulating member, in which an accommodating portion is provided in a wall portion of the exhaust passage at a position facing the heat insulating member, and the heat insulating member provides thermal insulation between the exhaust passage and the battery cell when the safety valve is not opened, and is separated from the holding member and accommodated in the accommodating portion by the gas that is released from the safety valve when the safety valve is opened, so as to provide thermal insulation between the gas that is released from the safety valve and the wall portion of the exhaust passage. According to the present disclosure, the wall portion of the exhaust passage and the battery cells can be protected from high-temperature gas that is released from the battery cells, while suppressing increases in costs. BRIEF DESCRIPTION OF THE DRAWINGS Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: FIG. 1 is a diagram schematically illustrating a battery pack according to an embodiment; FIG. 2 is a diagram illustrating a heat insulating member for thermally insulating a battery cell from an exhaust passage; FIG. 3 is a diagram illustrating a state in which the heat insulating member that is separated from a holding member is accommodated in an accommodating portion to thermally insulate wall portions of the exhaust passage from gas when a safety valve is opened; FIG. 4 is a diagram illustrating a structure of the accommodating portion; FIG. 5 is a diagram schematically illustrating the battery pack according to a modification; and FIG. 6 is a diagram illustrating a case in which the safety valve in the battery pack according to the modification is open. DETAILED DESCRIPTION OF EMBODIMENTS A battery pack according to an embodiment of the present disclosure will be described in detail below. Note that the present disclosure is not limited to the embodiment that is described below. FIG. 1 is a diagram schematically illustrating the battery pack according to the embodiment. The battery pack 1 is a power storage device in which a battery module 3, in which a plurality of battery cells 2 is stacked, is accommodated inside a case 4. The battery pack 1 is installed in an electrified v