Natural Polymer Template for Low-Cost Producing High-Performance Ti3C2Tx MXene Electrodes for Flexible Supercapacitors

MXenes, two-dimensional (2D) transition-metal carbides and nitrides with high electrical conductivity, show outstanding potential for energy storage applications. However, the aggregation and restacking of 2D MXene nanosheets seriously decrease the performance of MXene-based electrodes. Instead of using high-cost artificial templates, herein, we select natural rubber (NR) latex-containing uniform sub-macroparticles as sacrificial templates and successfully construct three-dimensional interconnected porous MXene foam. This porous structure effectively prevents the restacking of MXene nanosheets and accelerates the transfer of electrolyte ions during charging and discharging, which significantly enhances capacitance and rate performance. By adjusting the loading of latex, we find that MXene foam (MXF)-70% provides both improved specific capacitance of 480 F g^-1 at 2 mV s^-1 and superior rate performance (42.1% residual at 1 V s^-1) with excellent cycling stability of 97.1% capacitance retention after 10000 cycles at 50 mV s^-1. Additionally, the low cost of natural rubber latex provides an alternate route to produce foam electrodes on a large scale for portable and integrated supercapacitors.