Promoting a Stable Interface Using Localized High-Concentration Carbonate-Based Electrolyte for Li Metal Batteries

Rechargeable lithium metal batteries (LMBs) using high-voltagecathodes have been attractive in delivering high-energy density, butit is still challenging to reach excellent cycling performance forpractical applications due to the notorious reactivity of metalliclithium as well as the unstable nature of the cathode. Here, we demonstratea formulated carbonated-based electrolyte with LiPF6 thatsupports the most commercial aggressive and high-voltage cathode withthe combination of cosolvent, diluent, and additives to address theissue in LMBs by providing a stable interface/interphase on both theanode and cathode. The electrolyte's solvation structure isadjusted to reduce free carbonate solvents in the decomposition andcontribution to the solid-electrolyte interphase (SEI) formation.The thin LiF-rich SEI and achieved uniform Li deposition affordeda high Coulombic efficiency of 99.5% for Li|Cu half cells and goodcycling stability in Li||NMC811 full cells. The Li||NMC811 full cellsshowed good cycling life with a capacity retention of & SIM;80%over 280 cycles at an areal capacity of 4.0 mAh cm(-2), the lean electrolyte of 5 & mu;L mAh(-1), anda thin 50 & mu;m Li metal, demonstrating its advantage toward practicalapplications.

Automated summary

A formulated carbonated-based electrolyte with LiPF6 was developed, which addressed the issue of poor cycling performance in high-voltage cathodes by providing a stable interface/interphase on both the anode and cathode.