Making MXenes more energetic in aqueous battery

MXenes, featuring outstanding electronic conductivity, abundant surface functional groups, tunable interlayer structure, and interfacial chemistry, have aroused increasing attention in safe aqueous batteries (ABs). However, current MXene-based ABs suffer from the issues of inadequate energy density due to their low specific capacity and limited output voltage, which hinders the wide applications of MXenes. Herein, we comprehensively appraise the four charge storage mechanisms in constructing high-capacity/voltage MXene-based electrodes and the state-of-the-art strategies toward energetic ABs. Finally, we render the insights properly for the future development of next-generation MXene-based ABs. MXenes, featuring outstanding electronic conductivity, abundant surface functional groups, tunable interlayer structure, and interfacial chemistry, have aroused increasing attention in safe aqueous batteries (ABs). However, current MXene-based ABs suffer from the issues of inadequate energy density due to their low specific capacity and limited output voltage, which hinders the wide applications of MXenes. Herein, we comprehensively appraise the four charge storage mechanisms in constructing high-capacity/voltage MXene-based electrodes and the state-of-the-art strategies toward energetic ABs. Finally, we render the insights properly for the future development of next-generation MXene-based ABs. Intrinsic voltage plateau of a Nb2CTx MXene cathode in an aqueous electrolyte induced by high-voltage scanningLi et al.JouleOctober 11, 2021In BriefIn the past decade, two-dimensional MXenes have been a rising star in the energy storage field, featured by fast surficial redox and high-rate energy storage. However, typically, MXene electrodes exhibit capacitive behavior with a rapidly descending output voltage during discharge. Moreover, the absence of distinct voltage plateaus deteriorates their capacities and energy densities. Our work outlines an efficient route toward achieving high-energy-density MXene electrodes with distinct discharge voltage plateau through a high-voltage-scanning approach. Full-Text PDF