Solid electrolyte material and preparation method therefor, solid electrolyte and battery

Abstract

The invention relates to a solid electrolyte material. The solid electrolyte material comprises a crystalline state inorganic solid electrolyte and an amorphous state inorganic solid electrolyte, wherein the crystalline state inorganic solid electrolyte is one or more of crystalline state inorganic solid electrolytes expressed by a formula of Li<10 plus or minus 1>AB<2>X<12>; and the amorphous state inorganic solid electrolyte is one or more of amorphous state inorganic solid electrolytes expressed by a formula of <y>Li<2>X<-(100-y)>P<2>X<5>. The invention also provides a preparation method for the solid electrolyte material, a solid electrolyte comprising the solid electrolyte material, and a battery comprising the solid electrolyte. The solid electrolyte material provided by the invention is simple in preparation process, excellent in ionic conductivity, particularly not reduced by a metal negative electrode easily, and relatively high in stability; and the prepared electrolyte has longer cycle life, so that the battery is more durable.

Description

technical field [0001] The invention relates to a solid electrolyte material, a preparation method thereof, a solid electrolyte and a battery. Background technique [0002] At present, inorganic solid electrolytes are divided into crystalline, amorphous and glass-ceramic according to their crystal structure, and the solid electrolyte is a single component. Crystalline solid electrolytes are generally prepared by solid-phase sintering, such as the crystalline electrolyte Li 10 GeP 2 S 12 , The ion conductivity can reach 12mS / cm. Amorphous solid electrolyte can be prepared by ball milling or high temperature melting and quenching, such as 75Li 2 S·25P 2 S 5 Amorphous electrolyte with an ionic conductivity of 3.4×10 -4 S / cm. The structure of glass-ceramic solid electrolyte is between amorphous and crystalline, and it is generally prepared by crystallization of amorphous solid electrolyte, such as 75Li 2 S·25P 2 S 5 Glass-ceramic solid electrolyte with an ionic conduc...

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Problems solved by technology

[0003] The above three types of inorganic solid electrolytes have the following disadvantages: the high-valence elements Si, Ge and Sn in the crystalline electrolyte with high ionic conductivity are easily reduced by the negative electrode when they are matched with the metal lithium negative electrode, resulting in the loss of local activity of the electrolyte; Amorphous inorganic solid electrolyte yLi 2 X-(100-y)P 2 x 5 (X=O / S / Se) (65≦y≦85) has a relatively low ionic conductivity, usually lower than 10 -3 S cm -1 The crystallization ratio of crystalline components in glass-ceramic state and CN101326673A disclosed lithium ion conduction sulfide class solid electrolyte is key, and crystallization ratio is too high and too low all can cause the ionic conductivity of electrolyte to reduce, thereby cause micro The preparation of crystal glass and the sulfide-based solid electrolyte is difficult

Moreover, the lithium ion conductive sulfide solid electrolyte disclosed by CN101326673A defines the crystalline components, that is, the solid PNMR has crystallization-induced crystalline components at the positions of 90.9±0.4ppm and 86.5±0.4ppm, which restricts the solid Further improvement of electrolyte ionic conductivity

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