Enhancing Performance of Anode-Free Li-Metal Batteries

Abstract

Because of their higher energy density, compared to lithium-ion batteries, rechargeable lithium-metalbatteries (LMB) have been considered one of the most attractive next-generation energy-storagesystems (ESS). A promising approach to improving LMB performance, that has gained interest inrecent years, is the use of anode-free lithium-metal batteries (AFLMB). Such battery configurationenables elimination of the problem of using excessive amounts of lithium in LMBs, hence increasingthe specific energy of the battery. This work explores the beneficial effects of integrating metal-oxidenanoparticles (MONPs) into the liquid electrolyte of AFLMB. It was found that the addition of lowconcentrations of MONPs significantly improves coulombic efficiency (CE), capacity retention (CR)and the Solid-Electrolyte-Interphase (SEI) properties. SEM images revealed a smoother lithiummorphology for MONPs cells and XPS analysis showed great differences in the SEI composition. Theresistance of the cell components, extracted via electrochemical impedance spectroscopy (EIS), hasbeen significantly lowered due to the addition of MONPs. The performance of the AFLMB, withoutMONPs, was 97.1% CE and CR of 70% within 12 cycles, while cells with 0.5% SnO2 , 1% Al2O3 and1% TiO2 was 99.1%, 98.8% and 99.4% CE, and CR of 70% within 39, 38 and 36 cycles, respectively.Combinations of two MONPs resulted in 99.9% CE, which is among the highest found in the literaturefor AFLMB.