Membrane containing active lithium sources, preparation method and lithium ion battery

Abstract

The invention discloses a membrane containing active lithium sources. The membrane comprises a membrane body and a coating containing the active lithium sources. The coating containing the active lithium sources is arranged on one side or double sides of the membrane body. The invention discloses a preparation method of the membrane containing the active lithium sources. The invention further discloses a lithium ion battery. The membrane has a low requirement for the technology environment, the active material with which the surface of the membrane is coated can make the membrane store a certain quantity of lithium sources, the lithium sources are provided for a lithium ion secondary battery system to compensate for the lithium ion loss caused by primary charging and discharging, the utilization rate of the positive-pole active material can be increased to about 96-98%, and the gram volume of secondary battery positive-pole active substances can be made to reach the ideal level of half cells. Meanwhile, the active material containing the lithium sources forms a solid layer to cover the membrane after the lithium sources are lost, so that a solid substance layer for supporting the membrane structure is formed, the heat stability of the membrane is improved, heat shrinkage of the membrane is prevented, and the safety performance of the battery is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a diaphragm containing active lithium sources, a manufacturing method and a lithium ion battery. Background technique [0002] At present, there are two main diaphragm coating technologies in the market, one is PVDF, which achieves the purpose of improving the hardness of the battery cell and fixing the shape of the cell through the adhesion of the diaphragm to the pole piece; the other is coating with ceramic particles. The safety performance is improved by preventing large-area short circuit caused by thermal shrinkage through the ceramic ion-supported diaphragm, and at the same time improving the wetting performance of the diaphragm and electrolyte, and improving the self-discharge of the battery. Lithium cobalt oxide and lithium manganese oxide materials in lithium-ion batteries have low utilization rate. The ideal half-cell utilization rate can re...

AI Technical Summary

Problems solved by technology

Lithium cobalt oxide and lithium manganese oxide materials in lithium-ion batteries have low utilization rate. The ideal half-cell utilization rate can reach 98%, but the actual utilization rate is only 90-93%, resulting in serious waste of resources; The loss of lithium source is large, and the efficiency is low for the first time, resulting in a poor level of positive electrode material capacity, which directly limits the industrial application of alloy negative electrode materials

U.S. Patent US20130260239A1 provides a lithium source for the system by adding SLMP (Stabilized Lithium Metal Powder) on the surface of the negative electrode, but after all, the environmental requirements are very harsh, and the production cost is high, so it is difficult to realize large-scale industrialization.

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