Solid-state battery and preparation method therefor

Abstract

The invention relates to a solid-state battery and a preparation method therefor. The preparation method for the solid-state battery comprises the steps of preparing a stacking structure, wherein the stacking structure at least comprises a positive electrode layer and a solid-state electrolyte layer arranged on the positive electrode layer; the positive electrode layer comprises positive electrode active material granules and solid-state electrolyte granules; and performing quick interface heating on the stacking structure to enable the interface of at least one kind of the positive electrode active material granules and the solid-state electrolyte granules in the positive electrode layer to be fused to generate an interface fused phase, so as to directly connect the positive electrode active material granules and the solid-state electrolyte granules.

Description

Technical field [0001] The present invention generally relates to the field of new energy sources, and more particularly, to a simple, rapid, and large-scale method for preparing solid-state batteries, and solid-state batteries prepared by the method. Background technique [0002] In recent years, the fast-developing electric vehicle and energy storage industries have put forward higher requirements for the energy density, cost, cycle characteristics and safety characteristics of secondary batteries represented by lithium-ion batteries and lead-acid batteries. Take lithium-ion batteries as an example. Conventional lithium-ion batteries mainly use graphite anodes. The theoretical capacity of graphite anodes is 372mAh / g. At present, major domestic graphite anode manufacturers, such as Jiangxi Zichen and Shenzhen Beiterui, have achieved 365mAh. The capacity of / g is close to the limit of theoretical capacity. In order to achieve higher energy density and power density, people began...

AI Technical Summary

Problems solved by technology

Oxide-based solid-state battery companies, such as Sakti3, etc., generally use magnetron sputtering to deposit LiPON electrolyte and lithium cobalt oxide cathode materials on the surface of metal lithium, but this method has high production costs and the thickness of LCO is thin. The energy density of the battery is low

Solid-state battery companies based on the development of sulfide electrolytes, such as Toyota, Samsung, Hitachi Zosen, and Fuji, generally use pressurized technology to prepare solid-state batteries, but this requires high technical requirements and high production costs.

Polymer-based solid-state batteries have light weight, good viscosity, easy film formation, good chemical stability, and can well inhibit the growth of lithium dendrites. However, the electrochemical window is less than 3.8V, so high-voltage cathodes cannot be used, making The energy density of the battery system is low, for example, the energy density of Seeo’s polymer battery is only 100wh / kg

[0004] In addition, compared with liquid electrolytes, solid electrolytes do not have interfacial wetting and fluidity, which makes the preparation of solid-state batteries more difficult than liquid batteries.

In order to solve the problem of the interface, the researchers tried the sintering process to solve the interface contact between the solid electrolyte and the solid electrolyte and between the solid electrolyte and the positive electrode material. However, a long sintering time tends to cause a large interface resistance between the positive electrode and the electrolyte.

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