Surface oxygen-containing functional groups: A key tradeoff in carbon-based energy storage devices

Abstract

Carbon materials, being of pivotal significance in energy storage, have garnered considerable attention for their surface oxygen-containing functional groups (OCFGs), which improve the capacitance of electric double-layer capacitors (EDLCs) and the storage capacity for Li + and Na + in wettability and pseudocapcitance. OCFGs reveal a complex chemical structure within carbon materials, containing various types, sites, and quantities. Unraveling the potential interactions between the OCFGs and carbon materials can achieve better treatment outcomes for carbon materials. This comprehensive review summarizes formation mechanisms, characterization techniques, strategies for regulating OCFGs on carbon materials, as well as the influence of carbon material morphology. It elucidates their profound impact on the electrochemical performance of EDLCs, lithium-ion, and sodium-ion batteries/capacitors. Furthermore, it explores recent progress in materials and methodologies aimed at optimizing the role of OCFGs in energy storage systems. Finally, this review also identifies the existing challenges and outlines the future prospects in this area.