Metal organic sulfide (mosb) cathode material and lithium-free secondary battery

Abstract

The application discloses a metal organic sulfide (MOSB) positive electrode active material, a preparation method and a lithium-free secondary battery, and belongs to the technical field of new energy secondary batteries. The MOSB material is formed by a plurality of metal ions, an organic ligand and sulfur through a covalent bond to form a stable lattice structure, and the lattice sulfur fixation form can eliminate the polysulfide shuttle effect. The MOSB material can directly participate in an electrochemical reaction as an independent positive electrode active material, the volume expansion rate is less than 5% in a 2.0-3.5V charge-discharge interval, and the intrinsic conductivity is greater than or equal to 10-3 S / cm (four-probe method, 25 DEG C). The lithium-free secondary battery based on the MOSB material is composed of the MOSB positive electrode, a lithium-free negative electrode, a sulfur-tolerant electrolyte and a functional separator. The lithium-free secondary battery does not contain lithium, cobalt and nickel elements in the whole battery system, has a voltage platform of 2.8-3.3V, an energy density of 300-500 Wh.kg-1, a cycle life of greater than or equal to 2000 times at a 1C rate, and no combustion and explosion risk under extreme working conditions. The application is free from the dependence on rare and precious metals, has low cost and excellent cycle stability, and has the potential for engineering production.

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