Exploring the potential of MBenes in AC filtering

Layered two-dimensional nanomaterials show great promise in enhancing the specific capacitance of electrochemical capacitors used for alternate current filtering applications. However, the frequency response of these materials is often limited by the inherently slow ion transport kinetics. In this work, a novel two-dimensional transition metal borides (MBene) material, CrB, was successfully synthesized through a safe and simple one-step etching method without additives. This material was then employed as the electrode in symmetric electrochemical capacitors designed for alternate current filtering purposes. The CrB-based electrochemical capacitors exhibit an exceptionally low RC time constant of 0.75 ms, along with a specific capacitance of 564 mu F cm(-2) at 120 Hz and a substantial negative phase angle of 60.3 degrees. Furthermore, the study delved into the ion diffusion and adsorption characteristics on the two-dimensional CrB surface through theoretically investigations, confirming its rapid charging and discharging capabilities. The findings not only support the potential application of novel MBene materials as electrodes in future energy storage devices but also open up avenues for the advancement of MBene-based electrochemical capacitors.