Positive electrode material, preparation method thereof, and lithium ion battery comprising the same

Abstract

The invention belongs to the technical field of a lithium ion battery, and particularly relates to an anode material for a lithium ion battery. The anode material for the lithium ion battery comprises lithium cobalt oxide which is of a layer structure and is doped with at least one element of magnesium, titanium, zirconium and aluminum; an active lithium-rich layer is distributed on the surface of the lithium cobalt oxide; and a structural formula of the anode material is Lia(LiCo(1-x)MxO2). Compared with the prior art, the anode material of the lithium ion battery has the characteristics that Li with content a belongs to an active component and is in a metastable state; when the battery is charged for the first time, the Li with the content a is released from an anode and moves to a cathode, so that irreversible Li<+> with the content increases and is used for forming an SEI (Solid Electrolyte Interphase) on the surface of a cathode sheet, and reversible Li<+> returning back to the lithium cobalt oxide increases, and therefore, the reversible capacity of the lithium ion battery can be improved, and the energy density of the lithium ion battery can be improved. Furthermore, the invention further discloses a preparation method of the anode material and a lithium ion battery containing the anode material.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a positive electrode material for lithium ion batteries, a preparation method thereof, and a lithium ion battery containing the positive electrode material. Background technique [0002] As mobile consumer electronics products such as mobile phones, cameras, and tablet computers are becoming thinner and lighter, people have higher and higher requirements for the energy density of mobile power supplies. Lithium-ion batteries have the highest energy density among commonly used mobile power sources, so they have attracted people's attention and favor. [0003] The energy density of lithium-ion batteries is mainly affected by factors such as positive electrode materials, separators, negative electrode materials, and electrolytes. Among them, commonly used positive electrode materials include lithium cobaltate and nickel-cobalt-manganese composite ternary mat...

AI Technical Summary

Problems solved by technology

Under this preparation process, the added Li combines with Co, O and doping elements to form doped lithium cobalt oxide. If the amount of Li added is increased, the excess Li cannot be converted into active components to improve the capacity of lithium cobalt oxide. , but to form Li 2 CO 3 and LiOH and other inactive components, these inactive components will increase the pH of lithium cobaltate, increase the risk of gelation of lithium cobaltate slurry during stirring, and a large amount of Li 2 CO 3 It will cause lithium cobalt oxide batteries to generate a lot of gas when they are stored at high temperature, which will seriously affect the appearance of the battery and cause safety accidents

Moreover, if the content of Li is too large, the lithium cobalt oxide lattice inside the formed Li + Occupied the Co 3+ The position will affect the stability of the lattice, thereby affecting the cycle performance of the battery

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