A Bio-Based Molecule to Afford a Lithium-Metal Battery by Modification with the Electrode–Electrolyte Interphase

Abstract

Lithium (Li)-metal batteries with LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) as the cathode are expected to reach excellent energy density batteries, but their performance is still far below what is projected. The key points in these batteries are regarded to be the solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI). Here, the bio-based molecule eugenol, a lignin monomer model compound, is used as an effectively modified molecule for establishing SEI and CEI stability for the first time. Lithium-ion (Li + ) uniform distribution is encouraged by the strong interaction between the phenolic hydroxyl group and Li + , which suppresses the growth of lithium dendrites. Additionally, eugenol is preferentially reduced to SEI at the anode and oxidized to CEI at the cathode, which lessens the side reaction between the electrolyte and electrode. Maintaining the stability of the electrode−electrolyte interphase helps to prevent materials from collapsing. As a result, the Li/Li cell cycling stability has been improved to 1500 h at 3 mA cm −2 , and the capacity retention rate of eugenol@Li/NCM811 batteries has remained at 50% after 500 cycles at 1C.