A nanoengineered lithium-hosting carbon/zinc oxide composite electrode material for efficient non-aqueous lithium metal batteries

Abstract

Achieving Coulombic efficiency values greater than 99.9% for Li metal cells is considered one of the most important requirements for the technology development of long cycle life in energy-dense Li metal batteries. However, owing to the volume changes in Li metal electrodes and Li reservoir loss during battery operation, this requirement has not yet been realized in Li metal cells. Here, to overcome these issues, we propose a zero-volume-change, complete-sealing design for a nanoengineered composite material consisting of multilayer reduced graphene oxide and zinc oxide. This composite electrode material can accommodate Li metal without showing negligible volume changes while promoting the formation of an inorganic-rich solid-electrolyte interphase. When the nanoengineered Li/reduced graphene oxide/zinc oxide electrode is tested in combination with a Li metal electrode in a coin cell configuration using non-aqueous electrolyte solutions, Li plating/stripping Coulombic efficiency values ranging from 99.9900% to 99.9999%, for almost 2,000 cycles at a current density of 1 mA cm⁻², can be calculated. Testing of the nanoengineered Li/reduced graphene oxide/zinc oxide electrode in combination with high-potential electrodes (for example, LiNi_0.8Co_0.1Mn_0.1O₂ or LiFePO₄) in non-aqueous coin cell configuration also demonstrates improved performance compared with the high-potential coin cells utilizing pristine Li metal electrodes.