Functional Additives Improve The Performance Of The Pc-based Electrolyte

We've known that the electrode/electrolyte interphase(SEI) plays an important role in lithium-ion batteries. It determines the safety, self-discharge, power capability, low temperature performance, faradic efficiency, and the irreversible capacity loss for the first charge cycle.Without increasing the batteries cost some functions of the Li-ion batteries can be improved distinctly through putting a few additives into the electrolyte of the batteries. This methode is a focus for improving the functions of Li-ion batteries in recent years.Comparative to EC-based electrolytes,PC-based ones has it's excellent property of low temperature, but limited by it's not so good property of film-forming on the anode electrode.This paper studied some electrolyte additives to improve the film-forming performance of the Li-ion batteries. The function process of this kind of additives is that the additives' discomposing reaction can occur before the electrolytes do at the first charge-discharge cycle, forming a fine SEI film, and avoiding or decreasing the discomposing reaction of electrolytes.To PC- based electrolytes, the addition of VA, ES and CuTF can prohibit the co-intercalation of PC, and improve the cyclic performance of MCMB electrode. SEM, FTIR study indicate that VA and ES take part in the presence of VA and ES, and the contents of ROLi and RCO3Li are reduced. And indicate that VA and ES went on reduce reaction and the products form a passive film which covers the surface of MCMB electrode and inhibit the co-intercalation of PC.