Solid electrolyte containing polymer with main chain containing sulfur, solid secondary lithium battery formed by solid electrolyte as well as preparation method and application of solid electrolyte

Abstract

The invention relates to a solid polymer electrolyte , in particular to a solid electrolyte containing a polymer with a main chain containing sulfur, a solid secondary lithium battery formed by the solid electrolyte as well as a preparation method and application of the solid electrolyte. The solid electrolyte comprises the polymer with the main chain containing sulfur, lithium salt and a porous supporting material; the thickness of the solid electrolyte is 20-800 microns, the mechanical strength of the solid electrolyte is 10-80MPa, the room-temperature ionic conductivity of the solid electrolyte is 5*10<-5>-7*10<-4>S/cm, and the electrochemical window of the solid electrolyte is 4.5-7V. The polymer solid electrolyte provided by the invention is liable to prepare, simple to form and goodin mechanical performance, has higher ionic conductivity and wider electrochemical window at the same time, can effectively inhibit growth of cathode lithium dendrites and can improve the interface stability and the long cycle performance of the battery.

Description

technical field [0001] The invention relates to a solid electrolyte, in particular a solid secondary lithium battery composed of a solid electrolyte containing a main chain sulfur-containing polymer and its preparation and application. Background technique [0002] In recent years, due to the shortage of resources and environmental pollution, new industrial technologies such as electric vehicles have developed rapidly, and the demand for high-performance lithium-ion batteries has become more and more urgent. Among them, solid-state lithium batteries have become a research hotspot due to their high safety and excellent high-temperature performance. Solid electrolytes in lithium batteries can be divided into inorganic solid electrolytes and polymer solid electrolytes. Compared with inorganic solid electrolytes, polymer electrolytes have lower conductivity, but they are easier to process and shape, and are suitable for large-scale industrial production, so they have more advant...

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Problems solved by technology

However, due to the singleness of the polymer skeleton, the polymer electrolyte cannot simultaneously have excellent electrochemical properties, good mechanical properties and high safety.

US4792504 describes a polymer electrolyte containing poly(dimethacrylate) / polyethylene oxide, but its mechanical properties are not high

CN1428363A describes a nanoporous polymer electrolyte membrane, which has excellent charge and discharge performance and cycle performance, but electrolyte is added to the electrolyte, which is a gel polymer electrolyte, which cannot fundamentally solve the leakage and leakage of electrolyte, etc. safe question

US2017005356, US2017018781, and WO2016196873 filed by Ionic Materials Company describe polymer electrolytes prepared with polyphenylene sulfide and polysulfone containing benzene rings as the matrix. The two electrolyte systems have high ionic conductivity, but due to the The thioether is connected to the benzene ring and thioether group in the main chain of polysulfone containing benzene ring, which leads to the high electronic conductivity of the polymer electrolyte and increases the risk of short circuit of the battery

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