Metal/graphene oxide batteries

Abstract

Based on the spontaneous redox reaction between metal and graphene oxide, a novel type of metal/graphene oxide (M/GO) batteries is developed to convert chemical energy into electricity, including Li/GO, Na/GO, Zn/GO, Fe/GO, and Cu/GO batteries. They are fabricated via the simple assembly of metal foils with GO films, in which M plays the role of anode, and GO acts as both cathode and separator. Among them, Li/GO battery generates the highest specific capacity of 1572 mAh cm−3 (about 1604 mAh g−1). The energy density of M/GO battery is determined by the contact area of M with GO. Therefore, three-dimensional (3D) M/GO battery will deliver higher energy in comparison to 2D planar M/GO battery. As expected, a semi-solid 3D-Cu/GO redox flow battery (RFB) is assembled by 3D Cu foam with flowing GO/ionic-liquid catholyte. Its specific capacity is ca. 97 times that of Cu foil/GO RFB. Besides, a compressible, all-solid-state, and pressure-responsive 3D-GO/Zn battery is also fabricated. It can accurately control the energy output in response to pressure stimulations without the aid of conventional battery management system. Beyond those demonstrated in this work, the concept of M/GO battery will shed light on the design of similar electrochemical power sources.