US-20260128484-A1 - BATTERY MODULE

US20260128484A1US 20260128484 A1US20260128484 A1US 20260128484A1US-20260128484-A1

Abstract

A battery module includes a battery element, a first current collector electrically connected to the battery element, a second current collector disposed facing the first current collector and electrically connected to the first current collector, and a plurality of resin insulators disposed therebetween, in which the battery element includes a cathode, an anode, and a resin separator disposed between the cathode and the anode, the first and second current collectors are electrically insulated by the insulators in a portion at which the insulators are disposed therebetween, and are electrically connected to each other in a portion at which the insulators are not disposed therebetween, a melting point of the resin of the insulators is lower than a melting point of the resin of the separator, and the insulators melt and spread between the first and second current collectors as a result of generating heat due to passage of electricity therebetween.

Inventors

Nobuo Matsui

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260507
Application Date: 20250912
Priority Date: 20241106

Claims (5)

1 . A battery module comprising: a battery element; a first current collector that is electrically connected to the battery element; a second current collector that is disposed facing the first current collector and that is electrically connected to the first current collector; and a plurality of insulators made of resin that are disposed between the first current collector and the second current collector, wherein the battery element includes a cathode, an anode, and a separator that is made of resin, and that is disposed between the cathode and the anode, the first current collector and the second current collector are electrically insulated by the insulators in a portion at which the insulators are disposed between the first current collector and the second current collector, and are electrically connected to each other in a portion at which the insulators are not disposed between the first current collector and the second current collector, a melting point of the resin of the insulators is lower than a melting point of the resin of the separator, and the insulators melt and spread between the first current collector and the second current collector as a result of the first current collector and the second current collector generating heat due to passage of electricity.
2 . The battery module according to claim 1 , wherein a thickness of the insulators is less than a thickness of the first current collector, and also less than a thickness of the second current collector.
3 . The battery module according to claim 1 , wherein the insulators are arrayed in a first direction, and extend in a second direction that is different from the first direction.
4 . The battery module according to claim 3 , wherein a width of each of the insulators in the first direction is narrower than a width between the insulators that are adjacent to each other in the first direction.
5 . The battery module according to claim 1 , wherein a melting point of the resin of the insulators is higher than an upper limit value of temperature during normal use of the battery module.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2024-194450 filed on November 6, 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 technology disclosed in the present specification relates to a battery module. 2. Description of Related Art A battery module is disclosed in Japanese Unexamined Patent Application Publication No. 2007-66806 (JP 2007-66806 A). The battery module according to JP 2007-66806 A includes a first current collector, a second current collector that is electrically connected to the first current collector, a plurality of insulators disposed between the first current collector and the second current collector, and a battery element that is electrically connected to the first current collector. The first current collector and the second current collector are electrically insulated by the insulators at portions at which the insulators are disposed therebetween, and are electrically connected at portions at which no insulator is disposed therebetween. SUMMARY In a battery module, an excessive current may flow due to, for example, external short-circuiting or the like. This may cause the battery module to become abnormally hot, which can conceivably result in damage to the battery element, or the like. Accordingly, the present specification provides technology that enables abnormal temperature rising to be suppressed in a battery module. According to a first aspect of the present technology, a battery module includes a battery element, a first current collector that is electrically connected to the battery element, a second current collector that is disposed facing the first current collector and that is electrically connected to the first current collector, and a plurality of insulators made of resin that are disposed between the first current collector and the second current collector. The battery element includes a cathode, an anode, and a separator that is made of resin, and that is disposed between the cathode and the anode. The first current collector and the second current collector are electrically insulated by the insulators in a portion at which the insulators are disposed between the first current collector and the second current collector, and are electrically connected to each other in a portion at which the insulators are not disposed between the first current collector and the second current collector. A melting point of the resin of the insulators is lower than a melting point of the resin of the separator. The insulators melt and spread between the first current collector and the second current collector as a result of the first current collector and the second current collector generating heat due to passage of electricity. According to this configuration, when an excessive current flows through the battery module, causing the first current collector and the second current collector to generate abnormal heat, the insulators melt and spread between the first current collector and the second current collector. This enables passage of electricity between the first current collector and the second current collector to be interrupted or suppressed. As a result, excessive current can be suppressed from flowing through the battery module, and accordingly abnormal temperature rise in the battery module can be suppressed. Also, the insulators melt before the separator melts, and accordingly the battery element can be protected. With a second aspect, in the above first aspect, a thickness of the insulators may be less than a thickness of the first current collector, and also may be less than a thickness of the second current collector. With a third aspect, in the first or second aspect, the insulators may be arrayed in a first direction, and extend in a second direction that is different from the first direction. With a fourth aspect, in the third aspect, a width of each of the insulators in the first direction may be narrower than a width between the insulators that are adjacent to each other in the first direction. With a fifth aspect according to any one of the first to fourth aspects, a melting point of the resin of the insulators may be higher than an upper limit value of temperature during normal use of the battery module. 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 module according to an embodiment; FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; and FIG. 3 is a diagram schematically illustrating the battery module according to the embodiment. DETAILED DESCRIPTION OF EMBODIMENTS A batt