Safety battery and preparation method thereof

Abstract

The invention provides a safety battery. The safety battery comprises a positive electrode, a negative electrode and a diaphragm, wherein the positive electrode comprises a positive electrode current collector layer, a first solid electrolyte coating arranged on the surface of the positive electrode current collector layer, a positive electrode active material coating arranged on the surface of the first solid electrolyte coating, and a second solid electrolyte coating arranged on the positive electrode active material coating. According to the safety battery disclosed by the invention, when internal short circuit is caused by mechanical abuse of the battery, the solid electrolyte coating coating the surface of the aluminum foil can effectively block direct contact between a negative electrode active material and the aluminum foil; the diaphragm coated with the solid electrolyte can reduce diaphragm shrinkage and prevent short circuit point expansion, the solid electrolyte coating coating the surface of the positive pole piece and the solid electrolyte coated with the positive active material can also effectively reduce the thermal runaway risk during short circuit in the battery, and fire and explosion of the battery are avoided. In addition, the invention also provides a preparation method of the safety battery.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a safe battery and a preparation method thereof. Background technique [0002] Lithium-ion battery is one of the most important inventions in the 20th century. It is widely used in mobile phones, computers, smart wearable products, power tools, models, drones and other electronic devices. It is called consumer lithium-ion battery. Lithium-ion batteries are light in weight, rechargeable, and have strong electric power. As their size and market scale continue to expand, lithium-ion batteries also usher in opportunities for rapid development. [0003] The energy density of lithium ions is getting higher and higher, and safety issues are getting more and more attention. When lithium batteries are subjected to mechanical abuse (acupuncture and heavy object impact, etc.) The thermal runaway problem of lithium batteries causes the batteries to catch fire and explode, whic...

AI Technical Summary

Problems solved by technology

At present, the technology to improve battery safety tends to be all-solid-state batteries, but all-solid-state batteries have problems such as non-wettability between solids and high interface resistance, and the preparation process of all-solid-state batteries is immature, basically does not meet the conditions for mass production, and the cost is relatively high. high

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