O3-type layered positive electrode material for sodium ion battery and method for improving purity of material through element doping

Abstract

The invention discloses an O3-type layered positive electrode material of a sodium ion battery and a method for improving the purity of the material through element doping. The positive electrode material is a sodium-based layered metal oxide NaA<x>B<1-x>O<2>, wherein A is a doping metal and is selected from large-ion radius transition metals with electrochemical activity, preferably Cu, Fe, Ni and Cr; and B is selected from transition metals with electrochemical activity, preferably Fe, Co, Ni, Mn, Ti and Cr, and the doping amount of the metal A is more than or equal to 0.05 and less than orequal to 0.5. According to the method, the structure of the layered positive electrode material of the sodium ion battery is regulated and controlled by regulating and controlling the types of dopingmetal elements and doping proportions, and the O3 type positive electrode material with a single structure and excellent performance is finally obtained; the material is prepared through early-stage material mixing, tabletting and high-temperature calcining, the process is simple and easy to operate, and raw materials are rich in source and low in price, so the practical application degree of thepositive electrode material is high; and the positive electrode material provided by the invention can provide a new insight for the optimal design of a layered positive electrode material structure of a high-performance sodium-ion battery, and has wide application prospects.

Description

technical field [0001] The invention belongs to the technical field of energy materials, and in particular relates to an O3 type sodium ion battery layered positive electrode material and a method for improving the purity of the material through element doping. Background technique [0002] With the further development of energy storage technology, sodium-ion batteries have received more and more attention from the industry and the scientific community, especially in the field of large-scale energy storage, which is expected by all walks of life. Sodium-ion batteries work similarly to lithium-ion batteries and are called "rocking chair batteries." Although the mass of Na is heavier than Li, and the theoretical energy density is lower than that of lithium-ion batteries, the advantage of sodium-ion batteries lies in the abundance and wider distribution of sodium resources (the abundance in the earth's crust is about 2.74%, while the lithium element Only 0.0065%), which makes ...

AI Technical Summary

Problems solved by technology

[0004] However, the phase structure prepared by the synthesis of some O3-type layered oxide cathode materials is impure, often accompanied by P2-type impurity phases.

Because the sodium content of these impurity phases is less than that of the original O3 type material, the capacity of the material cannot be fully utilized

In addition, mixed-phase materials will also be accompanied by more phase transitions during the charging and discharging process, which will affect the cycle performance of the material, and these drawbacks greatly limit its application.

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