Ceramic separator and lithium ion battery

Abstract

The invention provides a ceramic separator. The ceramic separator comprises a separator substrate, wherein ceramic paste is coated on a surface of at least one side of the separator substrate, a protection layer is formed on a surface of the separator substrate after the ceramic paste is dried, the ceramic paste is formed by mixing ceramic powder with mass percent of 20-70%, a flame retardant with mass percent of 20-70%, a binding agent with mass percent of 5-30% and a solvent, and the ceramic powder is of a hollow spherical or hollow pipe structure. The safety of a lithium ion battery employing the ceramic separator can be improved.

Description

【Technical field】 [0001] The invention belongs to the technical field of batteries, in particular to a ceramic diaphragm and a lithium ion battery using the ceramic diaphragm. 【Background technique】 [0002] Lithium-ion batteries have been widely used, especially as an energy source for electric vehicles, due to their high energy density, high operating voltage, and long cycle life. The existing lithium-ion battery electrolyte is usually composed of carbonate organic solvents, which have a low flash point and will burn in the air when heated or high temperature, posing a great safety hazard. In order to solve the above problems, the prior art includes the following two methods: one is to add a flame retardant to the electrolyte, but the resulting problem is that the electrochemical performance of the electrolyte is seriously affected; the other is to add a flame retardant to the electrolyte. Even if the diaphragm substrate shrinks or melts, the ceramic coating can still pre...

AI Technical Summary

Problems solved by technology

The existing lithium-ion battery electrolyte is usually composed of carbonate organic solvents, which have a low flash point and will burn in the air when heated or high temperature, posing a great safety hazard

In order to solve the above problems, the prior art includes the following two methods: one is to add a flame retardant to the electrolyte, but the resulting problem is that the electrochemical performance of the electrolyte is seriously affected; the other is to add a flame retardant to the electrolyte. Even if the diaphragm substrate shrinks or melts, the ceramic coating can still prevent the contact between the positive and negative electrodes, prevent large-area short circuits, and achieve the purpose of improving safety performance. However, the existing technology usually uses ordinary ceramic Powder coating, the specific surface area is only 10-20m 2 / g, the liquid absorption capacity is limited, resulting in poor battery high current charge and discharge performance, and low battery cycle life

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