A kind of positive electrode material of lithium ion battery and preparation method thereof, positive electrode and lithium ion battery

Abstract

The disclosure relates to a lithium-ion battery cathode material, a preparation method thereof, the cathode and the lithium-ion battery. The positive electrode material contains doped nickel-cobalt lithium manganese oxide particles, and the structural formula of the doped nickel-cobalt lithium manganese oxide particles is Li(Ni x co y mn 1‑x‑y‑p‑q‑r Zr p al q W r )O 2 , wherein 0.6≤x≤0.8, 0.1≤y≤0.2, 0.0005≤p≤0.0015, 0.002≤q≤0.006, 0.0003≤r≤0.0009; (003) of the XRD spectrum of the doped nickel-cobalt lithium manganate particles The peak intensity I of the diffraction peak 003 and the peak intensity I of the (104) diffraction peak 104 The ratio of 1.22≤I 003 / I 104 ≤1.25; the half-width of the (104) diffraction peak of the nickel-cobalt lithium manganese oxide particles is 0.23-0.25. The positive electrode material of the present disclosure contains doping elements Zr, Al and W, which improves the crystal structure, improves the structural stability and integrity of the material, thereby optimizing the cycle performance and safety performance of the nickel-cobalt lithium manganese oxide ternary material. The disclosed method has small doping amount, simple operation, easy control, and low production cost, and is suitable for large-scale industrial production.

Description

technical field [0001] The present disclosure relates to the field of lithium-ion batteries, in particular, to a lithium-ion battery positive electrode material, a preparation method thereof, a positive electrode, and a lithium-ion battery. Background technique [0002] As an important branch of energy saving, emission reduction and environmental protection, new energy vehicles represented by Tesla have attracted great attention from all over the world. "Energy saving and new energy vehicles" is an important part of the high-end equipment innovation project in "Made in China 2025", its importance is self-evident. As the core component that restricts the energy density, service life and safety of power batteries, the cathode material of lithium-ion batteries is particularly important for its research. [0003] Since 1980, Goodenough et al. proposed lithium cobalt oxide as the positive electrode material for lithium rechargeable batteries, which opened the prototype of lithiu...

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Problems solved by technology

[0006] Although the energy density of nickel-cobalt lithium manganate ternary material is high, there are many problems in its cycle performance and safety performance. With the increase of nickel element content, its energy density increases, but its cycle performance and safety performance worsened

During the delithiation / lithium intercalation process, the nickel-cobalt lithium manganate ternary material undergoes multiple phase transitions, which leads to changes in its unit cell parameters and unit cell volume microscopically, and shows cracks on the surface and interface of the material macroscopically, resulting in nickel The internal resistance of the lithium cobalt manganese oxide ternary material increases, the capacity fades seriously, and the cycle performance and thermal stability deteriorate

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