Cathode materials and applications for improving the interfacial stability of sulfide electrolytes

Abstract

The invention relates to a positive electrode material and application for improving the interface stability of a sulfide electrolyte. The general chemical formula of the cathode material is: Li 1‑z Z z Ni a mn b M1 c M2 d M3 e S x o 4‑x ; where 0≤z<1, 0<a≤0.5, 0<b≤1.5, 0≤c<2, 0≤d≤2, 0≤e≤2, 0.01≤x<0.65, a+b+c+ d+e=2; wherein, Z is a cation doped with a Li site, and the valence is +1; M1, M2, and M3 are respectively cations doped with a transition metal site; S is sulfur. The doping of anion S can effectively suppress the serious space charge layer effect and interdiffusion of elements between the sulfurized electrolyte and the layered oxide cathode material, reduce the electrochemical side reaction at the interface, thereby increasing the capacity, reducing the interface impedance, and optimizing the electrical conductivity of the material. chemical properties.

Description

technical field

[0001] The invention relates to the field of material technology, in particular to a positive electrode material for improving the interface stability of a sulfide electrolyte and its application. Background technique

[0002] Due to high voltage, high energy density, long cycle life, and stable battery chemistry, lithium-ion batteries are widely used in mobile devices, emergency power systems, and hybrid electric vehicles (HEV), etc., and have become a leader in various energy storage applications . At present, traditional lithium-ion batteries are limited by the low theoretical capacity of electrode materials, and there is limited room for further improvement of energy density, which makes it difficult to support the requirements of next-generation electronic devices for high-energy-density energy storage systems. In addition, the liquid electrolyte used in conventional lithium-ion batteries has safety risks such as flammability, explosion and leakage. Es...

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