Bidirectionally aligned MXene hybrid aerogels assembled with MXene nanosheets and microgels for supercapacitors

Abstract MXene nanomaterials are one of the most promising electrode material candidates for supercapacitors owing to their high conductivity, abundant surface functional groups and large surface area. However, electrodes based on MXene may result in low ion‐accessible surface area and blocked ion transport pathways because of the self‐restacking of MXene nanosheets. It is essential to suppress the self‐restacking of nanosheets and increase the electrochemical active sites in order to optimize the electrode. In this work, bidirectionally aligned MXene hybrid aerogel (A‐MHA) assembled with MXene nanosheets and microgels is prepared using a facile bidirectional freeze casting and freeze‐drying method. The bidirectionally aligned structure together with the three‐dimensional structured microgels in the A‐MHAs, can improve the ion‐accessible surface area and provide more barrier‐free channels by exposing more active sites and ensuring electrolyte transport freely. The A‐MHA with MXene microgels content of 40 wt% exhibits a high specific capacitance of 760 F·g −1 at 1 A·g −1 and a remarkable cyclic performance of 97% after 10,000 cycles at 100 mV·s −1 in 1 mol·L −1 H 2 SO 4 electrolyte. A‐MHAs show remarkable electrochemical properties and are of potential application in energy storage.