Li-Ni-Co-Mn-V-O quaternary lithium ion battery positive electrode material and preparation method thereof

Abstract

The invention provides a quaternary lithium ion battery positive electrode material (Li-Ni-Co-Mn-V-O). The invention also provides a corresponding synthesis method of the quaternary material. At the precursor synthesis stage, a vanadium element is introduced into a system by oxalic acid co-precipitation, a large amount of the V element can be enabled to be uniformly doped with a crystal to form anew quaternary positive electrode material, Mn can stably exist under an acid condition in a form of Mn<2+>, the reaction condition is easy to control, the synthesis process is simple, and the productis good in stability. In the quaternary lithium ion battery positive electrode material, the V is uniformly introduced in a fourth component, and the new Li-Ni-Co-Mn-V-O quaternary lithium ion battery positive electrode material is formed and can have favorable cycle and rate performance under a relatively high cutoff voltage (4.6V); and moreover, due to the reduction of Co content, the cost is reduced, the problem of an environment brought by Co is reduced, and thus, the commercial application value of a lithium ion battery is improved by the material.

Description

technical field [0001] The invention belongs to the technical field of cathode materials of lithium ion batteries. Background technique [0002] Due to its small size and high energy density, lithium-ion batteries are widely used in the fields of 3C and electric vehicles. From the perspective of the development trend of lithium-ion batteries, the development direction should be to reduce the cost of material synthesis and improve energy density and cycle stability. The cost and capacity constraints of lithium batteries are mainly concentrated on the positive electrode material. Compared to LiNiO 2 , LiMn 2 o 4 and LiCoO 2 , the ternary material (Li-Ni-Co-Mn-O) has high energy density, low cost and low toxicity, and is considered to be the most likely to replace LiCoO 2 Become one of the cathode materials for commercial lithium-ion batteries. As a kind of ternary system, LiNi 0.6 co 0.2 mn 0.2 o 2 (622) The ternary material increases the gram capacity of the materi...

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Problems solved by technology

[0004] The present invention aims to solve the complex and difficult-to-control synthetic conditions of existing high-nickel ternary lithium-ion battery materials and the problems that the battery has poor cycle and rate performance under higher cut-off voltage conditions (4.6V) (cycle at 1C current density) After 100 times, the capacity retention rate is 84.5%; charge and discharge at a current density of 5C, only 109.4mAh / g discharge specific capacity), a new four-component uniform introduction of vanadium is proposed to form a new Lithium-ion battery positive electrode materials and synthesis methods, and further promote the commercial application level of lithium-ion batteries

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