Effects of additive and separator on overcharge performance of lithium-ion battery

The elctropolymerization additives cyclohexylbenzene(CHB) and biphenyl(BP) were added to the electrolyte to improve the overcharge performance(1 C 10 V, 3 C 4.8 V) of prismatic lithium-ion battery with high capacity. Also the effect of separator on overcharge performance was investigated. The results of tests show that the pass rate of 1C 10 V overcharge test is increased by adding CHB and BP, the battery can be protected in 1 C 10 V overcharge test with 5% CHB+ 5% BP, and in 3 C 4.8 V overcharge test with the separator which owned higher puncture strength.Meanwhile the capacity retention and thickness after cycling were related to the additives and the separator. ?Additives were resulted in cycle performance degradation, while the performance of cycling could be improved by the good property of separator.