JP-7854851-B2 - Battery case and battery for non-aqueous electrolyte secondary battery

JP7854851B2JP 7854851 B2JP7854851 B2JP 7854851B2JP-7854851-B2

Inventors

岩田利生
白石幸司

Assignees

三井化学株式会社

Dates

Publication Date: 20260507
Application Date: 20220513

Claims (7)

It comprises an expanded graphite layer and a fiber-reinforced resin layer, The fiber-reinforced resin layer contains at least one of carbon fibers and glass fibers in an amount of 10% to 60% by mass relative to the total mass of the fiber-reinforced resin layer. Battery case for non-aqueous electrolyte rechargeable batteries.
The battery case for a non-aqueous electrolyte secondary battery according to claim 1, wherein the content of expanded graphite in the expanded graphite layer is 50% by mass or more relative to the total mass of the expanded graphite layer.
The aforementioned fiber-reinforced resin layer comprises a polypropylene resin or a polyamide resin, as described in claim 1, for a battery case for a non-aqueous electrolyte secondary battery.
The battery case for a non-aqueous electrolyte secondary battery according to claim 1, wherein the expanded graphite layer is arranged inside the battery case.
A battery case for a non-aqueous electrolyte secondary battery according to claim 1, further comprising an electromagnetic wave shielding layer.
The aforementioned fiber-reinforced resin layer contains an electromagnetic wave shielding filler, as described in claim 1, for a battery case for a non-aqueous electrolyte secondary battery.
A battery for a non-aqueous electrolyte secondary battery, comprising a battery case for a non-aqueous electrolyte secondary battery as described in any one of claims 1 to 6.

Description

This invention relates to a battery case for a non-aqueous electrolyte secondary battery and a battery for a non-aqueous electrolyte secondary battery. To reduce CO2 emissions during vehicle operation and increase the driving range of electric vehicles, vehicle weight reduction is more important than ever. From the perspective of improving weight reduction, it is conceivable to reduce the amount of metal used in battery packs and battery modules, or to use resin instead. On the other hand, there is a growing need to improve the safety of electric vehicles more than ever before. For example, various types of batteries, such as lithium batteries, can catch fire due to internal short circuits, overcharging, penetration by foreign objects, external overheating, and abnormal heat generation. As a non-aqueous electrolyte secondary battery capable of suppressing heat generation in the event of an abnormality such as an internal short circuit, for example, Patent Document 1 discloses a non-aqueous electrolyte secondary battery comprising a battery case, wherein an expanded graphite layer and a high thermal conductivity layer are arranged in the battery case, the expanded graphite layer consists of 70% by mass or more of expanded graphite and 30% by mass or less of a binder, and the thermal conductivity in the planar direction of the high thermal conductivity layer is higher than the thermal conductivity in the planar direction of the battery case and the thermal conductivity in the planar direction of the expanded graphite layer. Furthermore, as a battery cell storage case that can achieve both lightweight design and fire resistance, for example, Patent Document 2 discloses a battery cell storage case having a bottom plate on which multiple battery cells are placed, side plates erected around the bottom plate, and a top plate provided at the upper end of the erected side plates so as to face the bottom plate, wherein the top plate has a first top plate constituent layer and a second top plate constituent layer located inside the first top plate constituent layer, the first top plate constituent layer being either an aluminum layer with a thickness of 0.5 to 5.0 mm or a non-foamed resin layer, and the second top plate constituent layer being a polyurethane foam layer containing a flame retardant. As a resin battery cell housing that satisfies both chemical resistance and water permeability requirements, and also offers excellent productivity, for example, Patent Document 3 discloses a battery cell housing comprising at least a resin molded body and a metal layer formed on its surface. Japanese Patent Publication No. 2018-181519Japanese Patent Publication No. 2021-002420Japanese Patent Publication No. 2007-227121 The contents of the present invention will be described in detail below. The description of the constituent elements described below may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, the term "polymer" includes homopolymers and copolymers. In this specification, the "~" indicating a numerical range is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, the "~" indicating a numerical range means that the units listed before or after it refer to the same unit unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. The present invention will be described in detail below. (Battery case for non-aqueous electrolyte secondary batteries) The battery case for a non-aqueous electrolyte secondary battery according to the present invention comprises an expanded graphite layer and a fiber-reinforced resin layer, wherein the fiber-reinforced resin layer contains at least one of carbon fibers and glass fibers in an amount of 10% to 60% by mass relative to the total mass of the fiber-reinforced resin layer. The battery case for a non-aqueous electrolyte secondary battery according to the present invention (hereinafter also simply referred to as "battery case") is lightweight and has excellent flame retardancy due to the above configuration. The reason for this is not clear, but it is presumed to be as follows. The above battery case includes an expanded graphite layer. For example, if the battery catches fire, the flame will cause the expanded graphite layer to expand, acting as an insulating layer and exhibiting fire-resistant and flame-retardant properties. Furthermore, because the above battery case includes a fiber-reinforced resin layer, it is lighter than conventional battery cases with a metal layer. The following describes the details of each component in the battery case. <Fiber-reinforced resin layer> The battery case according to the present invention includes a fiber-reinforced resin layer. The fiber-reinforced resin layer is a layer containing a resin and