Current Collector-Free Reduced Graphene Oxide Aerogel Cathode for High Energy Density Dual-Ion Batteries

As an important indicator to evaluate battery performance, the energy density of commercial lithium ion batteries is close to the limit. Herein, for the first time, we reported that the reduced oxide graphene (rGO) aerogel can be directly used for the cathode of a dual-ion battery to achieve a superior specific energy density by reducing the dead weight of the battery. The porous structure of an rGO aerogel facilitates the penetration of the electrolyte and provides more active sites for energy storage. At the same time, the continuous graphene network benefits the electron transport. The lithium-rGO battery shows a discharge specific capacity of 94 mA h g^-1 at 1 A g^-1 and a superior specific energy density of 213 W h kg^-1 at 2141 W kg^-1. It is worth noting that this current collector-free electrode design would promote the development and application of graphene-based batteries with a high energy density.