Synergistical Stabilization of Li Metal Anodesand LiCoO2 Cathodes in High-VoltageLi∥LiCoO2 Batteries by Potassium Selenocyanate (KSeCN) Additive

Dramatic growth of lithium (Li) dendrite andstructural deterioration of LiCoO2(LCO) lead to rapid failureof a high-voltage Li parallel to LCO battery. The nitrile group (-Cxe0c9;N) isbeneficial to maintain the integrity of the LCO lattice due to itsstrong affiliation to Co ions, whereas the-Cxe0c9;N bond isincompatible with the Li metal anode, leading to form adeleterious solid electrolyte interphase (SEI)film. Herein, adual-functional electrolyte additive potassium selenocyanate(KSeCN) is introduced to construct stable and dense SEI/cathode electrolyte interphase (CEI)films by synergistic effectswith-Se and-Cxe0c9;N groups, resulting in uniform Lideposition and a stabilized LCO lattice during cycling. With atrace amount of KSeCN (0.1 wt %) in conventional carbonatedelectrolyte, the Li parallel to LCO battery exhibits promoted cycling performance at high charge cutoff4.6 V. This work provides astrategic guidance for rational design of electrolyte to construct stable SEI and CEIfilms, to achieve a high-energy-densityLi parallel to LCO battery with great performance.

Automated summary

In this study, a dual-functional electrolyte additive KSeCN is introduced to construct stable and dense SEI/CEI films by synergistic effects with -Se and -Cxe0c9;N groups, resulting in improved stability and cycling performance of the Li parallel to LCO battery.