A method for preparing a solid composite electrolyte membrane supported by a synchronous substrate

Abstract

The invention relates to the field of solid electrolyte membranes, in particular to a method for preparing a synchronous substrate-supported solid composite electrolyte membrane, comprising the following steps: a. Extruding ultra-high molecular weight or high-density polyolefin molten state slurry to form a cast film; b. The solid electrolyte molten slurry is evenly extruded on the surface of the cast sheet film at a temperature T1 to form a solid electrolyte coating to obtain a solid electrolyte coating-cast sheet substrate; c. solid electrolyte coating-cast sheet substrate at temperature Stretching is carried out in T2 to obtain a film; d. The stretched film is subjected to hot-pressing and setting to control thickness, and cooled to obtain a solid composite electrolyte membrane. By controlling the tensile parameters, the impregnation effect of the solid electrolyte on the porous carrier can be adjusted to form a continuous lithium-conducting channel, improve the lithium-conducting ability of the composite electrolyte, and avoid the subsequent separate impregnation steps, which can effectively improve the production efficiency of the composite electrolyte membrane.

Description

technical field [0001] The invention relates to the field of solid electrolyte membranes, in particular to a method for preparing a solid composite electrolyte membrane supported by a synchronous substrate. Background technique [0002] Lithium-ion batteries have attracted increasing attention due to their advantages such as high voltage, high specific energy, long cycle life, no memory effect, good safety performance and less environmental pollution. In recent years, they have been used in portable electronic devices, electric vehicles, energy storage and other applications The field ushered in explosive development. At present, lithium-ion batteries are continuing to progress towards high specific energy and high safety. The application of high-capacity electrode materials has brought about an increase in energy density, but the liquid electrolyte system is still the main factor restricting its safety performance. All-solid-state electrolytes are recognized as an effectiv...

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Problems solved by technology

However, it is difficult for the current all-solid electrolytes to have the above characteristics at the same time.

[0003] The existing film-forming methods of flexible polymer-based solid electrolytes mostly adopt casting or casting, and the mechanical properties of the film are still far behind the traditional ultra-high molecular weight polyolefin separators. In order to pursue higher ion conductivity, the electrolyte thickness The thinning of the thinner will further sacrifice its mechanical properties, thereby compromising the safety performance of solid-state batteries

Therefore, the industry tries to use the method of coating the electrolyte layer on the surface of the porous membrane carrier or impregnating the electrolyte solution with a porous polymer membrane with high porosity and large pore size. The strength and flexibility of the electrolyte membrane are easy to reduce the thickness of the electrolyte membrane under the premise of ensuring the mechanical strength, but the conventional preparation method is an asynchronous process, that is, the formation of the porous substrate and the penetration of the electrolyte slurry are independent processes, and the electrolyte penetration effect cannot be achieved. Controlling and subsequent penetration takes a lot of time to restrict the improvement of production efficiency

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