Artificial Interface Derived from Diphenyl Ether Additive for High‐Voltage LiNi0.5Mn1.5O4 Cathode

Hong Yun Yue; Zhan Li Han; Liang Liang Tao; Yao Fa Zhang; Lan Wang; Xiang Nan Li; Yan Hong Yin; Wei Guang Yang; Shu Ting Yang

Index: 10.1002/celc.201800011

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Abstract

Diphenyl ether (DPE) is investigated as a film‐forming additive to improve the cyclic stability of LiNi0.5Mn1.5O4 at high voltage and elevated temperature (55 °C). Addition of DPE in the baseline electrolyte significantly improves the capacity retention of LiNi0.5Mn1.5O4 at elevated temperature. Its capacity retention increases from 41.2 % at the baseline electrolyte to 90.5 % after 0.1 vol% DPE is added to the baseline electrolyte in 100 cycles. Calculations demonstrate that DPE is oxidized preferentially to the baseline electrolyte. The experimental results show that a robust and uniform film is generated on the LiNi0.5Mn1.5O4 surface, alleviating the subsequent electrolyte decomposition and protecting LiNi0.5Mn1.5O4 from transition metal dissolution and structural destruction.