Ternary material, preparation method and battery

Abstract

The invention provides a ternary material, a preparation method and a battery. The chemical general formula of the ternary material is Li (Ni<x>Co<y>A )MO2, wherein M is a modifying element and comprises one or a combination of at least two of boron, tungsten, thallium, strontium, niobium or phosphorus, A is Al or Mn, x is more than 0.5 and less than 1, y is more than 0 and less than 0.5, z is more than 0 and less than 0.5, x + y + z = 1, a is more than or equal to 0.95 and less than or equal to 0.99, and a + b = 1. Special element modifiers are introduced into crystal lattices and the surfaces of the crystal lattices, so that the crystal face energy of the ternary material is regulated and controlled, the grain size and the growth direction are controlled, the structure, the size and the arrangement mode of primary particles in the material are optimized, generation of micro-cracks in the particles caused by anisotropic changes of the volume of the crystal lattices is relieved, the interface side reaction of the electrolyte is inhibited, and the electrochemical stability of the material is improved. Excellent grain orientation arrangement is beneficial to diffusion of lithium ions and improvement of the dynamic performance of the material.

Description

technical field [0001] The invention belongs to the technical field of cathode materials, and relates to a ternary material, a preparation method and a battery. Background technique [0002] Lithium-ion batteries (lithium secondary batteries) are more and more favored by the battery industry for their advantages of light weight, long life, clean and environmental protection. As the key material of lithium-ion battery, the positive electrode material has always been the focus of research and development in the industry. At present, the mainstream positive electrode materials of lithium-ion batteries include lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide, and nickel-cobalt-manganese ternary materials, and there are NCA (nickel-cobalt-aluminum) series, LOL (lithium-rich manganese solid solution) and other emerging materials. Materials have been added to it and have been widely used commercially. Among them, ternary materials, especially NCA materials, m...

AI Technical Summary

Problems solved by technology

[0004] The expansion / shrinkage of the unit cell volume of the ternary positive electrode material in the process of deintercalating lithium leads to the accumulation of internal stress in the particles, resulting in cracks and breakage of the particles, which intensifies the erosion of the material by the electrolyte and deteriorates the electrochemical performance of the material.

However, the control of the microstructure of the precursor requires high precision of the synthesis conditions, difficult process, poor stability, and high preparation cost.

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