Two-dimensional MXene based anodic slurry electrodes for vanadium redox flow batteries

Vanadium redox flow batteries (VRFBs) are a promising energy storage technology with potential toward supporting the transition to green energy. However, optimizing electrode materials to improve battery performance remains a challenge. Slurry electrodes have recently gained attention for their advantages over conventional carbonaceous electrodes but require further investigation for effective utilization in flow battery systems. To address these issues, we investigated two-dimensional (2D) Ti 3 C 2 T x MXene slurry electrodes in VRFBs. We evaluated different concentrations (0.25, 0.5, and 1.0 wt.%) of MXene-based anodic slurry electrodes through comprehensive flow battery tests, including polarization, charge-discharge cycling, and electrochemical impedance spectroscopy . Rheological and hydrodynamic measurements were also conducted to analyze the physical properties of the slurry electrodes. Our findings reveal a 70 % higher voltage and 46 % increase in depth of discharge with the addition of 0.5 wt.% MXene slurry (MX_0.5) compared to the baseline graphite particle suspension electrode. Additionally, MX_0.5 exhibited enhanced rheological and hydrodynamic properties, leading to improved flow characteristics and a significant reduction in pressure drop within the battery system. The enhanced performance of Ti 3 C 2 T x was attributed to its unique 2D structure, high surface area, and specific surface chemistry, which collectively enhanced the electrochemical properties of the slurry electrodes.