Secondary battery

Abstract

A secondary battery (1) is provided with: a container (2) for accommodating an electrolyte; an electrode body (3) which is provided inside the container (2) and constitutes a power-generating element; a pressure release valve (2b1) which is provided in the container (2) and discharges gas generated inside the container (2); and an insulating body (8) which is provided between the pressure release valve (2b1) and the electrode body (3), and is provided away from the pressure release valve (2b1) and covers the pressure release valve (2b1). This insulating body (8) comprises a plurality of openings (8c) which constitute gas flow paths.

Description

technical field [0001] The present invention relates to secondary batteries. Background technique [0002] Non-aqueous electrolyte secondary batteries with high energy density (such as lithium-ion secondary batteries) as large and high-capacity power sources used in electric vehicles (EV) or hybrid vehicles (HEV), electric bicycles, forklifts, etc. It has attracted attention, and is being developed with the aim of increasing the size and capacity while considering long life and safety. As a large-capacity power supply, a battery pack containing a plurality of batteries connected in series or in parallel has been developed in order to increase driving power. [0003] As a non-aqueous electrolyte secondary battery, for example, a flat electrode group (electrode body) in which a strip-shaped positive electrode and a negative electrode are wound into a flat shape via a strip-shaped separator (separator) is used on both sides of a metal foil. ). In order to extract the electri...

AI Technical Summary

Problems solved by technology

[0009] However, in the above-mentioned non-aqueous electrolyte secondary battery, when an abnormality such as overcharging or vehicle collision occurs, gas generated due to electrolyte decomposition or the like tends to stagnate in the container of the battery, and the full gas is not quickly released from the pressure. The valve discharges to the outside, and there may be problems such as expansion or rupture of the container

In particular, when an abnormality such as overcharging or vehicle collision occurs, the contents of the container (for example, aluminum foil or resin damaged by gas ejection) may be ejected from the pressure release valve. Therefore, when the contents When the pressure opening valve is blocked by objects, the gas cannot be discharged, and the expansion or rupture of the container will be accelerated.

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