Positive electrode material with low surface residual alkali as well as preparation method and application thereof

Abstract

The invention discloses a positive electrode material with low surface residual alkali. The positive electrode material is obtained by reacting an original positive electrode material with a boron compound and / or organic weak acid, wherein the original positive electrode material comprises any one or more of LiNi<y>Co<z>DM<1-y-z-u>O2, LiCo<1-w>T<w>O2, Li2Mn<1-j / 2>Q<j / 2>O4 and LiFe<1-s>R<s>PO4.According to the invention, the electrochemical performance of the positive electrode material can be improved, a coating material generated by the reaction has good thermal stability, chemical stability and high conductivity, a stable and compact solid electrolyte interface film can be formed on the surface of the electrode, the overcharge resistance and the rate capability of the lithium ion battery can be effectively improved, and the cycle life of the lithium ion battery is remarkably prolonged.

Description

technical field [0001] The invention relates to the technical field of lithium battery materials, in particular to a positive electrode material with low surface residual alkali and its preparation method and application. Background technique [0002] Lithium-ion batteries have outstanding advantages such as small weight, high energy density, long cycle life, high working voltage, no memory effect, good safety performance, and environmental friendliness. Hybrid electric vehicles and other power battery fields. [0003] In the process of synthesizing positive electrode materials, in order to compensate for the volatilization of lithium during high-temperature calcination, the content of lithium will be slightly increased during the batching, and the excess lithium is generally expressed as Li 2 In the presence of O, Li 2 O and CO in the air 2 and H 2 O reacts to Li 2 CO 3 And LiOH, the pH of the material is high, it is easy to absorb moisture and deteriorate, and the co...

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Problems solved by technology

[0003] In the process of synthesizing positive electrode materials, in order to compensate for the volatilization of lithium during high-temperature calcination, the content of lithium will be slightly increased during the batching, and the excess lithium is generally expressed as Li 2 In the presence of O, Li 2 O and CO in the air 2 and H 2 O reacts to Li 2 CO 3 And LiOH, the pH of the material is high, it is easy to absorb moisture and deteriorate, and the compatibility with the binder becomes poor, resulting in poor dispersion and stability of the slurry, and jelly phenomenon is easy to occur, making the coating process impossible

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