Tuning Interphase Chemistry to Stabilize High-Voltage LiCoO2 Cathode Material via Spinel Coating
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION(2022)
Abstract
Cathode electrolyte interphases (CEIs) are critical to the cycling stability of high-voltage cathodes for batteries, yet their formation mechanism and properties remain elusive. Here we report that the compositions of CEIs are largely controlled by abundant species in the inner Helmholtz layer (IHL) and can be tuned from material aspects. The IHL of LiCoO2 (LCO) was found to alter after charging, with a solvent-rich environment that results in fragile organic-rich CEIs. By passivated spinel Li4Mn5O12 coating, we achieve an anion-rich IHL after charging, thus enabling robust LiF-rich CEIs. In situ microscopy reveals that LiF-rich CEIs maintain mechanical integrity at 500 degrees C, in sharp contrast to organic-rich CEIs which undergo severe expansion and subsequent voids/cracks in the cathode. As a result, the spinel-coated LCO exhibits a high specific capacity of 194 mAh g(-1) at 0.05 C and a capacity retention of 83 % after 300 cycles at 0.5 C. Our work sheds new light on modulating CEIs for advanced lithium-ion batteries.
MoreTranslated text
Key words
LiCoO2 Cathode,Lithium-Ion Batteries,Solid,Cathode Electrolyte Interphase (SEI,CEI),Spinel Coating
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined