Jianlian Lan, Qinfeng Zheng, Hebing Zhou
Jul 17, 2019
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Influential Citations
44
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Journal
ACS applied materials & interfaces
Abstract
We report a novel electrolyte additive, bis(trimethylsilyl)carbodiimide, that effectively stabilizes high voltage lithium-rich oxide cathode. Charge/discharge tests demonstrate that even trace amount of bis(trimethylsilyl)carbodiimide in a baseline electrolyte improves the cycling stability of this cathode significantly, either in Li-based half cells or graphite-based full cells, where the capacity retention after 200 cycles between 2 V and 4.8 V at 0.5 C is enhanced from 40% to 72% and 49% to 77%, respectively. Analyses using physical characterizations and theoretical calculations reveal that this additive not only builds a protective film on cathode, but also eliminates the detrimental hydrogen fluoride via its strong coordination with hydrogen fluoride or proton.