Bilayered nanoporous graphene/molybdenum oxide for high rate lithium ion batteries

Developing advanced lithium-ion batteries that afford both high energy density and high power density has been one of the crucial research targets in the field of electrochemical energy storage. Realization of fast Li⁺ storage would require a smart electrode design that enables simultaneous enhancements in ion and electron transports as well as a fast and facile bulk-form solid-state reaction. Here we report a high-performance 3D bilayered composite electrode constructed by bicontinuous nanoporous graphene and thin molybdenum oxide stacking films. The novel electrode offers fast kinetics of Li⁺ diffusion and reactions and, consequently, delivers a large specific capacity of 710 mAh g^-1, the excellent rate performance of charging within seconds and an ultra-long lifetime over 13,000 discharge-charge cycles. High and stable volumetric capacities up to 900 mAh cm^-3 have also been achieved with the squeezed composite electrodes. This study shines light into the realization of a high-performance graphene-based porous electrode for advanced lithium-ion batteries and will inspire the development of new 3D hybrid materials for high-rate and large-capacity electrochemical energy storage.