Sodium-ion battery nickel-based precursor capable of being used for filling conductive material and positive electrode material

Abstract

The invention discloses a sodium-ion battery nickel-based precursor capable of being used for filling a conductive material and a positive electrode material. The chemical formula of the precursor is NixMyMoz (OH) 2, wherein x is greater than or equal to 0.6 and less than 1, y is greater than 0 and less than or equal to 0.2, z is greater than 0 and less than or equal to 0.2, x + y + z = 1, and M is Cr or Nb. The chemical formula of the positive electrode material is NamNixMyMozO2, wherein m is greater than or equal to 0.67 and less than or equal to 1, and the conductive material is a conductive polymer material. According to the invention, the loose and porous precursor of the sodium-ion battery is prepared by adopting an industrially mature precursor preparation process, then the loose and porous positive electrode material is synthesized by adopting a high-temperature solid-phase method, and finally, the conductive material is filled into internal gaps of the positive electrode material, so that the conductivity of the conductive material is fully exerted, mechanical stress accumulation of the positive electrode material in the charging and discharging process is buffered, and the effect of protecting the structure of the positive electrode material is achieved. The traditional manganese element is not used, the influence of structural collapse and capacity fading caused by the Jahn-Taller effect of the manganese element is reduced, meanwhile, the nickel content is increased, the nickel and Mo, Cr or Nb are coordinated, and the structural stability and electrochemical performance of the positive electrode material are further improved.

Description

technical field [0001] The invention relates to the field of sodium-ion battery materials, and mainly relates to a precursor of a cathode material for a sodium-ion battery and a preparation method for the cathode material, in particular to a nickel-based precursor and anode material for a sodium-ion battery that can be used to fill conductive materials. Background technique [0002] The rapid commercialization of lithium-ion batteries has promoted the efficiency of human storage and utilization of clean energy, and is widely used in mobile communications and new energy vehicles. Due to the uneven distribution and rising cost of lithium resources, as well as the high cost of cobalt resources, sodium-ion batteries have developed rapidly as the most potential alternative batteries, and the development of new cathode materials for sodium-ion batteries is particularly important. And the sodium-ion battery has the same working principle as the lithium-ion battery, but the situatio...

AI Technical Summary

Problems solved by technology

However, this type of material is prone to defects in multi-potential platforms and cation migration during long cycling

These will lead to problems such as slow kinetics, capacity loss, and structural collapse during the intercalation / desodiumation process.

The layered oxides of sodium-ion batteries are mostly manganese-based oxides. The Jahn-Teller distortion of manganese has a great influence on the cathode materials of sodium-ion layered oxides, resulting in capacity attenuation, output potential attenuation, and kinetic hysteresis.

Moreover, unlike the fixed nickel-cobalt-manganese layered oxide positive electrode material of lithium-ion batteries, sodium-ion batteries do not have fixed element combination materials, and most of the synthesis methods are different, which makes industrial production impossible.

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