Contemporary Amperex Technology Co., Ltd.

Yan Zhou

Changlong Han

Xiaomei Wang

Jianwei Zhu

Jiqiong Liu

Feng Huan

Kun Yu

Chenghua Fu

Bin Jiang

Wenhao Liu

Feng Xu

The present invention discloses a Lithium ion battery and an electrolyte thereof, the electrolyte comprising an organic solvent, a lithium salt and an additive. The additive comprises a cyclic fluoro carbonate (A), a cyclic phosphazene (B), a cyclic sulfate and a lithium fluoro oxalate borate (D). The lithium fluoro oxalate borate (D) has following formula:  Compared with the prior art, the electrolyte of the present invention may form a stable CEI and SEI film on the surface of positive and negative electrodes, protect the interface between positive and negative electrodes, improve the acidic atmosphere of Lithium ion battery electrolyte, and reduce the damage effect of HF on the interface between positive and negative electrodes, while reducing low temperature resistance of lithium-ion battery, improving cycle life, high temperature storage performance, safety performance and rate capability of lithium-ion battery.

Lithium-ion battery and its electrolyte

The present invention discloses a Lithium ion battery and an electrolyte thereof, the electrolyte comprising an organic solvent, a lithium salt and an additive. The additive comprises additive (A) cyclic fluoro carbonate, additive (B) cyclic phosphazene (B), and additive (C) cyclic sulfate. The additive B cyclic phosphazene has the following general structural formula:  Compared with the prior art, the electrolyte of the present invention may form a stable CEI and SEI film on the surface of positive and negative electrodes, protect the interface between positive and negative electrodes, improve the acidic atmosphere of Lithium ion battery electrolyte, and reduce the damage effect of HF on the interface between positive and negative electrodes, thereby improving cycle life, high temperature storage performance, and safety performance of lithium-ion battery.

The present disclosure provides an electrolyte and an electrochemical energy storage device. The electrolyte comprises an electrolyte salt and an additive. The additive comprises a sulfonic ester cyclic quaternary ammonium salt and a fluorocarbon surfactant. Under the combined effect of the sulfonic ester cyclic quaternary ammonium salt and the fluorocarbon surfactant, a dense, uniform and stable passive film can form on a surface of each of a positive electrode film and a negative electrode film of the electrochemical energy storage device, and infiltration capability of the electrolyte on each of the passive film of the positive electrode film and the negative electrode film can be increased at the same time, so as to decrease electrode polarization inside the electrochemical energy storage device and make the electrochemical energy storage device have excellent rate capability, low temperature discharge performance and high temperature storage performance.

Electrolyte and electrochemical energy storage device

Growing community of inventors

Ningde, China

Yan Zhou