Structure optimization of graphene aerogel-based composites and applications in batteries and supercapacitors
Liyun Cao, Caiwei Wang, Yixuan Huang
Abstract
Compared with traditional two-dimensional graphene, graphene aerogels possess better research values and broad application prospects because of high specific surface areas and good mechanical stabilities. However, limited electron transportation abilities and weak surface polarity of graphene aerogels lead to poor electrochemical performance. The problem can be solved by preparing graphene aerogel-based composites (GACs). Structure optimization of GACs and applications in batteries and supercapacitors are introduced briefly in this paper. The unique three-dimensional porous structure of graphene aerogels provides many loading sites for non-metal/metal atoms, non-metal compounds, metal compounds and bimetal compounds. Adsorption capacities, redox capacities and conductivities of GACs are enhanced by optimized structure, including pore structure, phase structure, lattice structure and micro structure. The performance of Li-ion batteries, Na-ion batteries, Li-S batteries, flow batteries and supercapacitors are also improved. The structure of GACs is achieved by precursor processing technology and drying technology. Various processing methods are summarized to provide researchers with reference. In addition, current research status of GACs is also focused in this paper, proposing existing problems and future research directions.