Lithium-rich ceramic coated diaphragm and preparation method thereof

Abstract

The invention discloses a lithium-rich ceramic coating diaphragm and a preparation method thereof. The lithium-rich ceramic coating diaphragm comprises a base membrane, wherein a coating layer formedby coating lithium-rich ceramic slurry is arranged on the surface of the base membrane, the lithium-rich ceramic slurry comprises the following raw material components in parts by weight: 10-60 partsof lithium-rich ceramic powder, 3-10 parts of a binder and 0.5-10 parts of a cross-linking agent, the cross-linking agent has N=N double bonds, the binder has a CH3-CH2-CH2-structure, and the binder and the cross-linking agent are connected through bonding. The preparation method of the lithium-rich ceramic coated diaphragm comprises the following steps: (1) synthesizing lithium salt and ceramic powder together, and calcining to form lithium-rich ceramic powder; (2) blending and dispersing the lithium-rich ceramic powder, a binder, a cross-linking agent and water to obtain lithium-rich ceramicslurry; and (3) uniformly coating the surface of a base membrane with the lithium-rich ceramic slurry, and performing high-temperature, ultraviolet irradiation, illumination and electron beam actionto obtain the lithium-rich ceramic coated diaphragm. The lithium-rich ceramic coated diaphragm prepared by the method is high-temperature-resistant and high in stability, and the service life and thebattery capacity of a lithium battery can be prolonged and improved.

Description

technical field [0001] The invention relates to the technical field of lithium battery separators, in particular to a lithium-rich ceramic coated separator and a preparation method thereof. Background technique [0002] With the continuous development of the battery industry, the continuous adjustment of national policies and the continuous improvement of users' requirements for mileage, the capacity of lithium batteries is getting higher and higher, and the content of lithium ions determines the level of battery capacity. Due to the continuous lithium insertion and delithiation during the charge and discharge process and the formation of the SEI film during the formation of the battery, the free lithium ions in the battery will continue to decrease. As a result, the capacity of the battery continues to decrease. [0003] The main material of the diaphragm is PE or PP. Due to the characteristics of the material itself, it will soften at high temperature, and its dimensional...

AI Technical Summary

Problems solved by technology

[0004] The existing method of lithium supplementation is to add lithium ions to the binder of the positive and negative electrodes, which can play a certain role in supplementing lithium ions during use, but in the later stage, as lithium ions are delithiated, the binder will be damaged The performance is reduced, affecting other performances of the lithium battery

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