Lithium ion battery

Abstract

The invention relates to the field of electrochemistry, in particular to a lithium ion battery. The lithium ion battery comprises a positive pole piece, a negative pole piece, an isolating membrane and electrolyte, wherein the positive pole piece comprises a positive current collector and a cathode active material layer; the cathode active material layer comprises a cathode active material and a cathode additive; the cathode additive is selected from a lithium phosphate salt compound, the electrolyte comprises an electrolyte and a solvent, the electrolyte further comprises an acid removing agent and a film forming additive, the acid removing agent is selected from a cyclic anhydride compound, and the film forming additive is selected from a boroxane compound. According to the invention, the cathode additive is introduced into the positive electrode plate, the lithium salt can be stabilized by introducing the acid removing agent and the film forming additive into the electrolyte of thebattery, so that the lithium salt is prevented from being decomposed to generate HF to accelerate dissolution of positive manganese, HF in the electrolyte can be removed, and the cycle performance and / or storage performance of the battery cell are effectively improved.

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...

AI Technical Summary

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

Images