Electrocatalytic oxygen reduction of three-dimensional carbon fiber-based composites for seawater oxygen-dissolved battery

One-step hydrothermal reduction method was used to prepare three-dimensional carbon fiber brush-based graphene-platinum (CFB/Pt-G) composites to improve the electrocatalytic oxygen reduction activity of cathode materials for seawater oxygen-dissolved battery. Characterization results show that the reduced graphene oxide of as-prepared graphene-platinum composite displays the few-layer folded structure. In addition, Pt nanoparticles with the polycrystalline structure dispplay a preferential growth along the crystal plane of (111) and are mainly distributed around the defect cavities of folded graphene. Electrochemical results show that the diffusion-limited current density of CFB/Pt-G composite tested with 1600 rpm/min in 3.5% NaCl solution reaches 5 mA/cm(2), while that of CFB/G is only 2.64 mA/cm(2). Battery discharge results show that the maximum volume power density of CFB/Pt-G-Mg battery with a stable open voltage of 1.73 V is 81 times as much as the commercial seawater battery SWB1200.