A kind of battery thermal runaway protection and its preparation method and mold

Abstract

The present invention provides a battery thermal runaway guard, a preparation method and a mold thereof. The battery is a single battery or a battery pack. The guard includes a heat insulating unit, and the heat insulating unit includes a rectangular parallelepiped with openings at both ends. The inner wall is provided with a channel parallel to the axial direction of the unit, the thermal insulation unit is provided with a temperature alarm for reaching a threshold temperature, the wall of the thermal insulation unit includes an outer layer, a middle layer and an inner layer, and the preparation method of the protective piece includes the following steps: Assemble the mold; prepare the flame retardant material, inject the flame retardant material into the mold; cool and release the mold; press the cast-molded frame and the flame retardant plate, and the mold used includes a shell with an open upper end and a battery model placed on the bottom plate of the shell. Taking advantage of the flame-retardant and heat-insulating properties of flame-retardant materials, as well as the advantages of low density and light weight, the inner layer is cast and molded to make the flame-retardant material appear in a specific shape and structure, giving full play to its flame-retardant and heat-insulating properties, and the method is simple and easy to implement. accomplish.

Description

Technical field: [0001] The invention relates to a battery protection device and the preparation of the protection device, in particular to a battery thermal runaway protection part, a preparation method thereof and a mold. Background technique: [0002] Lithium-ion batteries, which are widely used, have fire accidents from time to time, triggering large-scale recalls of related products, bringing safety hazards to users, and causing major direct economic losses to enterprises and industries related to lithium-ion batteries. [0003] Under certain abuse conditions (such as overcharge, high temperature, short circuit, etc.), lithium-ion batteries are prone to thermal runaway. During this process, the internal and surface temperatures of the battery will suddenly rise to several hundred degrees, and the battery will release energy in the form of combustion or explosion. , and eventually the battery structure is destroyed and the electrical performance is lost. At this stage, ...

AI Technical Summary

Problems solved by technology

[0006] The flame retardant materials of the existing lithium-ion batteries are mostly coated on the positive and negative electrodes and separators inside the lithium-ion battery by coating. Although this method can partially slow down the ignition and combustion of lithium-ion batteries Or containment effect, but due to the arrangement in the limited space inside the battery, the shape and quality of the flame retardant material are affected. Generally, the thickness of the coating layer is only 0.5-10μm, resulting in unsatisfactory flame retardant effect. At the same time, due to the flame retardant The coating applied on the positive and negative plates or diaphragm of the battery will inevitably affect the capacity, power performance or other electrical properties of the battery itself

In addition, there is also a method of adding a flame retardant as an additive to the electrolyte of a lithium-ion battery to control or block the flame generated when the lithium-ion battery is thermally runaway. This method also places a flame-retardant material inside the battery to reduce the The flame retardant effect is not good, and it is not conducive to the ion conductance of the battery electrolyte, which leads to a decline in the electrical performance of the battery

In addition, there is also a method of encapsulating the lithium-ion battery in a closed rigid cavity and passing an inert gas inside. Although this method can effectively curb the spread of thermal runaway of the lithium-ion battery, it requires high strength and sealing performance of the cavity. are high, and the heavy rigid shell, cumbersome process and high cost constitute the bottleneck of the promotion and use of this method

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