Surface and interface engineering: Graphene-based freestanding electrodes for electrochemical energy storage

Next-generation energy storage methods are closely related to green recovery in the post-pandemic period and the future energy structure. Advanced graphene-based freestanding electrodes with highly tunable electronic structures and mechanical stability present superior electrochemical performance, which are among the most promising candidates for achieving efficient energy storage. However, the ever-increasing demand for energy has triggered significant room for the growth of material and energy efficiencies of graphene-based freestanding electrodes. Fortunately, their intrinsic reactivity can be improved by atomic-level tailoring of the surfaces and interfaces of electrodes. Therefore, there is an urgent need for researchers to grasp the relationship between the structure and electrochemical performance of graphene-based freestanding electrodes. In this review, we presented a focused discussion and multidimensional analysis of graphene-based freestanding electrodes, including the predictive design of valence electron structure, mechanistic understanding of conversion and storage, and performance evaluation in practical application. Moreover, future research aspects of the graphene-based freestanding electrodes are proposed.