Negative electrode material layer suitable for all-solid-state battery, preparation method of negative electrode material layer, negative plate and all-solid-state battery

Abstract

The invention discloses a negative electrode material layer suitable for an all-solid-state battery, a preparation method of the negative electrode material layer, a negative plate and the all-solid-state battery. The negative electrode material layer comprises a network-shaped structure formed by mutually overlapping polymer fibers, and a negative electrode active substance, a sulfide solid electrolyte and a conductive agent which are dispersed and bonded in the network-shaped structure. In the negative electrode material layer, the polymer fiber is used as a binder to construct the network-shaped structure, uniform dispersion of the negative electrode active substance, the sulfide solid electrolyte and the conductive agent is facilitated, and the sulfide solid electrolyte has good ion conductivity and is dispersed in the network-shaped structure to provide an ion transmission channel for charging and discharging of the battery, so that the addition of electrolyte is avoided, an all-solid-state battery is assembled, and the safety performance of the battery is improved.

Description

technical field [0001] The invention relates to the technical field of batteries, and relates to a negative electrode material layer suitable for all-solid batteries, its preparation method and application, and in particular to a negative electrode material layer of all-solid-state batteries, its preparation method, negative electrode sheets and all-solid-state batteries. Background technique [0002] With the popularization of electronic products and new energy vehicles, lithium batteries as their power sources are becoming more and more popular due to their advantages such as light weight, small size, high working voltage, high energy density, high output power, high charging efficiency and no memory effect. As more and more attention has been paid to it, it is inevitable that the safety and energy density requirements of lithium batteries are also getting higher and higher. [0003] The electrolyte used in lithium-ion batteries widely used in the market is an organic liqu...

AI Technical Summary

Problems solved by technology

Liquid electrolysis system is in a liquid state that is easy to flow at room temperature. After the battery is subjected to strong impact or internal expansion of the battery, the battery package is easily damaged, and the liquid electrolyte will leak out.

Because the liquid electrolyte contains a large amount of flammable and explosive organic solvents, it poses a great safety hazard

[0005] In addition, it is difficult to reduce the amount of liquid electrolyte used in liquid lithium-ion batteries, which makes it difficult for us to improve the mass energy density and volume energy density of lithium-ion batteries.

[0006] The all-solid-state battery technology is still in the research and development stage. At present, the method of wet homogenate coating is mainly used for the preparation of pole pieces, but the sulfide solid-state electrolyte is unstable with most solvents. There is a reaction, which makes the ionic conductivity of the sulfide electrolyte decrease, thereby increasing the impedance of the pole piece and the battery, reducing the battery rate performance, and affecting the cycle performance of the battery

In addition, the addition of solvent increases the drying, solvent recovery and other processes, which increases the cost and may cause environmental pollution.

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