All-solid-state battery and preparation method thereof

Abstract

The invention discloses an all-solid-state battery and a preparation method thereof. The all-solid-state battery comprises a positive electrode plate, a solid-state electrolyte layer and a negative electrode plate, wherein the positive electrode plate comprises a current collector and a positive electrode material layer, the positive electrode material layer comprises a positive electrode active material and an ionic conductive agent, the positive electrode active material is FeS, and the ionic conductive agent is sulfide. The solid electrolyte layer comprises solid electrolyte which is sulfide. The preparation method disclosed by the invention comprises the following steps: S1, blending positive electrode slurry, coating the positive electrode slurry on the current collector, and performing drying to obtain the positive electrode plate; S2, blending solid electrolyte slurry, coating the positive electrode plate with the solid electrolyte slurry, and performing drying to obtain the solid electrolyte layer; step S3, under a vacuum condition, superposing the negative electrode plate on the solid electrolyte layer, and performing heating and pressurizing to obtain the all-solid-statebattery. The all-solid-state battery which has high energy density, good cycle performance and rate capability and can be normally charged and discharged under self-sustaining voltage is obtained by the method disclosed by the invention.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to an all-solid-state battery and a preparation method thereof. Background technique [0002] In existing all-solid-state batteries, oxides are generally used as positive electrode active materials; sulfides with high deformation and high conductivity are used as solid-state electrolytes. [0003] But it has the following technical problems: [0004] (1) There is a potential difference between the positive electrode active material of the oxide and the solid electrolyte of the sulfide, which is easy to generate a space charge layer, so that the interface impedance between the positive electrode sheet and the solid electrolyte layer is large, which in turn leads to the cycle performance of the all-solid-state battery and Magnification performance is low. [0005] (2) The theoretical capacity of the positive active material of commonly used oxides is low (such as: LiCoO 2 The the...

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Problems solved by technology

[0011] The present invention provides an all-solid-state battery using FeS as the positive electrode active material to solve the problems of high interface impedance, low battery cycle performance and rate performance of all-solid-state batteries in the prior art, and low energy density of all-solid-state batteries in the prior art The problem

[0012] The present invention provides a method for preparing an all-solid-state battery that adopts a coating method and is heated and pressurized under vacuum conditions, so as to solve the problem that the all-solid-state battery prepared by the powder pressing method in the prior art can be processed without holding a pressurized mold. Charge and discharge, the technical problem that the battery capacity will decay rapidly, and the problem of low energy density due to the solid electrolyte layer being too thick

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