The use of electrolyte additives to improve the high temperature resilience of Li-ion cells
Date of Original Version
As part of our continuing efforts to develop advanced electrolytes to improve the performance of lithium-ion cells, especially over wide temperature ranges, we have investigated a number of electrolyte additives, which were incorporated into multicomponent electrolyte formulations with the intent of improveing the high temperature resilience. In the present work, we have investigated two Lewis base electrolyte additives developed at URI (1), namely dimethyl acetamide (DMAC) and N-methyl pyrrolidinone (NMP), which have been compared with other previously reported additives (i.e., vinylene carbonate, VC, and vinyl ethylene carbonate, VEC). These Lewis base stabilizing agents have been found to reversibly bind with PF5, preventing LiPF6 and carbonate solvents from undergoing decomposition at high temperature. These additives have been incorporated into a previously developed electrolyte consisting of LiPF6 dissolved in a ternary mixture of carbonates (2). It was determined that cells containing the electrolytes with the additives far outperformed the baseline solution with respect to the extent of capacity retention observed when subjected to high temperatures, with DMAc and VC yielding the best results © The Electrochemical Society.
Smart, M. C., B. L. Lucht, and B. V. Ratnakumar. "The use of electrolyte additives to improve the high temperature resilience of Li-ion cells." ECS Transactions 11, 29 (2007): 79-89. doi:10.1149/1.2938910.