Reentrant Micro-Cellular Foam Electrodes with Graphene/Carbon Nanotubes for Stretchable Lithium Metal Batteries

Abstract

Research on the human-friendly wearable devices has been rapidly developed these days. Smart watches, glasses, and phones belong to wearable devices, and there are strong demands to impart stretchability to such devices for conformable contacts to human body. Since these wearable devices are required to have a lot of power in small size, high-energy-density power devices are also required. In this study, reentrant micro-cellular foam electrodes with graphene/carbon nanotubes (CNTs) are presented for stretchable lithium metal batteries. The reentrant structure was formed by radial compressing of melamine foams taking advantages of structural stability of the foam structures under mechanical strains. Graphene and CNTs were used as lithium infiltration supports based on their high electrical conductivity and high mechanical stability. Lithium metal anodes were prepared by deposition of lithium onto the surfaces of graphene/CNTs by electroplating. The manufactured electrodes exhibited lower overpotential during Li stripping and plating than control samples of lithium metal foil anodes, and showed stable electrochemical performances under 50% of mechanical strain. The reentrant micro-cellular foam electrodes presents great potentials for advanced designs of electrodes for stretchable lithium metal batteries.