The impact of glycerol polyoxyethylene ether on the characteristics of lithium iron phosphate pastes and their electrochemical performance

Abstract

The traditional slurry preparation process is prone to problems such as easy agglomeration of particles and poor dispersion of active materials and conductive agents, etc. To solve these problems, this study synthesized a nonionic surface active agent type dispersant for lithium-ion batteries (PEG-18-C10) by reacting glycerol polyethylene glycol ether (PEG-18) and decanoic acid, which was used to improve the LiFePO4 cathode slurry in lithium-ion batteries and the electrochemical performance, this synthesis method is simple, low cost and easy to add. In addition, the effect of the dosage of this new dispersant on lithium-ion batteries was investigated. It was found that the dispersion uniformity and rheological properties of the cathode slurry could be improved with the addition of a 2 % dispersant compared with the traditional cathode slurry. Meanwhile, the electrochemical performance of the battery was improved, and the specific capacity of the first discharge was improved under the charging and discharging condition of 0.2 C, with the specific capacity of the first discharge being 168.5 mA h/g, while that of the unadded one was only 151.1 mA h/g, and the multiplicity performance of the battery was improved, with the specific capacity of the discharge at 5 C being 118.94 mA h/g, as compared with that of the addition of the conventional dispersant.