A lithium ion battery

Abstract

The invention relates to the field of electrochemistry, in particular to a lithium ion battery. The invention provides a lithium ion battery, comprising a positive pole piece, a negative pole piece, a separator and an electrolyte, the positive pole piece comprises a positive current collector and a positive active material layer, and the positive active material layer comprises a positive active material and Positive electrode additive, the positive electrode additive is selected from lithium phosphate compounds, the electrolyte includes electrolyte and solvent, the electrolyte also includes acid scavenger and film-forming additive, and the acid scavenger is selected from cyclic acid anhydride compounds , the film-forming additive is selected from boroxine compounds. The inventors of the present invention can stabilize the lithium salt by introducing positive electrode additives into the positive electrode sheet, and further introduce acid scavenger and film-forming additives into the electrolyte of the battery, thereby avoiding the decomposition of lithium salts to generate HF and accelerating the dissolution of positive manganese , and can remove HF in the electrolyte, effectively improving the cycle performance and / or storage performance of the battery.

Description

technical field [0001] The invention relates to the field of electrochemistry, in particular to a lithium ion battery. Background technique [0002] In recent years, portable electronic products, such as cameras, digital video cameras, mobile phones, notebook computers, etc., have been widely used in people's daily life. Among them, reducing the size, reducing the weight, and prolonging the service life are the trends and requirements for the development of portable electronic products. Therefore, the development of power supply products matching portable electronic products, especially the development of lightweight secondary batteries that can provide high energy density and long cycle life, has become an urgent requirement for the development of the battery industry. [0003] Lithium manganese oxide has the advantages of rich resources, low cost, high working voltage platform and low environmental toxicity, but its cycle performance and high temperature stability are poo...

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Problems solved by technology

[0003] Lithium manganate has the advantages of rich resources, low cost, high working voltage platform and low environmental toxicity, but its cycle performance and high temperature stability are poor. The main reason is that lithium manganate is prone to manganese dissolution, especially under acidic conditions.

The current electrolyte is mainly based on LiPF 6 Lithium salt, LiPF 6 In the process of circulation and storage, HF is easy to be generated, and HF catalyzes the dissolution of manganese in lithium manganate, resulting in a large amount of damage to the positive electrode, and the dissolved manganese element will be deposited on the negative electrode, thereby destroying the negative electrode

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