Unraveling Plasmonic Effects in Plasmon-Enhanced Lithium–Oxygen Batteries

Abstract

Rechargeable lithium–oxygen batteries have high theoretical energy density compared to the conventional Li–ion batteries. However, the recharging process is primarily disturbed by the large overpotential caused by sluggish OER kinetics. Plasmonic materials have unique properties with light, known as surface plasmon resonance (SPR). In this study, we demonstrate plasmonic effect in the Li–O2 battery system by incorporating gold nanoparticles on the Ketjen Black (KB) cathode. During discharge, plasmonic Au NPs induce a Li2O2 morphology change to small particles, which are easily decomposed during recharge. Most importantly, the SPR-induced hot carriers help to form and decompose Li2O2 and suppress carboxylate side-products, decreasing recharge voltages and increasing the round-trip efficiency up to 80.2%. Meticulous analyses of the catalytic properties of the Au NPs and the SPR-induced near-field enhancement and local heat effects are here additionally shared.Keywords: Li–O2 battery, Plasmonics, Light-enhanced batteries, Hot carriers, Near-field enhancement