Development of Electrolytes for Si-Graphite Composite Electrodes

Authors

Cao Cuong Nguyen, University of Rhode Island
Brett L. Lucht, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

7-13-2018

Department

Chemistry

Abstract

The performance of Si-graphite/Li cells and Si-graphite/NMC111 cells has been investigated in 1.2 M LiPF₆ /EC:DEC (1/1, w/w) with different electrolyte additives including LiNO₃, FEC, and MEC. The addition of additives into electrolytes result in a significant improvement in capacity retention compared to the standard electrolyte for Si-graphite/Li cells. The cells cycled with electrolyte containing 0.5 wt% LiNO₃, 5–10 wt% MEC or 10 wt% FEC have high capacity retention, at least 88%, while the cells cycled with standard electrolyte have lower capacity retention, 64%, after 100 cycles. Investigation of Si-graphite/NCM111 cells reveals that the cells cycled in electrolyte containing 0.5 wt% LiNO₃ have better capacity retention than cells cycled with 10 wt% FEC, 57.9% vs. 44.6%, respectively. The combination of 10% MEC and LiNO₃ further improves the capacity retention of the Si-graphite/NCM111 full cells to 79.9% after 100 cycles which is highest among the electrolytes investigated. Ex-situ surface analyses by XPS and IR-ATR have been conducted to provide a fundamental understanding the composition of the solid-electrolyte interphase (SEI) and its correlation to cycling performance.

Citation/Publisher Attribution

Nguyen, C.C., Lucht, B.L. Development of electrolytes for Si-graphite composite electrodes (2018) Journal of the Electrochemical Society, 165(10), pp. A2154-A2161. DOI: 10.1149/2.0621810jes

Available at: http://dx.doi.org/10.1149/2.0621810jes

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.