Improvement strategy of overcharging characteristics of a new type lithium iron phosphate battery in substation

In order to solve the hidden trouble for the long-term overcharging condition of lithium iron phosphate batteries, it is urgent to develop overcharging protective lithium iron phosphate batteries. A strategy combining autonomous equalization technology and passive equalization technology is proposed in this paper to improve the overcharging characteristics of lithium iron phosphate batteries. A certain proportion of oxidizing reductant is added to the electrolyte of ordinary lithium iron phosphate battery. And a comparative test is conducted between conventional lithium iron phosphate battery module and self-equalization lithium iron phosphate battery module in continuous overcharging state. The test results show that the proposed comprehensive strategy has reduced the voltage difference between the cells significantly, and the single cell voltage difference is small in the long-term overcharging process, so as to maintain the safe voltage level.