All-solid-state flexible supercapacitor of Carbonized MXene/Cotton fabric for wearable energy storage.

• Numbers of –F and –OH groups of Ti 3 C 2 T x could be removed by carbonizing. • Cotton fabrics contain the inherent flexibility after carbonizing. • High load of Ti 3 C 2 T x flakes on flexible substrate. • High areal capacitance of flexible supercapacitor based on Ti 3 C 2 T x /TiO 2 heterojunction. Flexible Carbonized MXene/Cotton fabric is prepared by dipping cotton fabric into Ti 3 C 2 T x suspension and carbonizing the composite fabric. Cotton fabric, embedded by Ti 3 C 2 T x flakes without the assistance of crosslinkers and binders, is the most used precursor of all carbon sources. In this work, Ti 3 C 2 T x flakes with different concentrations ranging from 2 to 8 wt% are loaded on cotton fabric and carbonized subsequently under the temperature from 800 to 1200 °C. The highest areal capacitance dramatically reaches to 794.2 mF cm−2 (233.6 F g−1) at a scan rate of 2 mV s−1 with 6 wt% Ti 3 C 2 T x at 1000 °C, which shows a 74% improvement compared to the carbonized cotton cloth dipped into the Ti 3 C 2 T x dispersions under same condition. Also, the assembled all-solid-state flexible supercapacitor remains 74% of capacitance even after 10,000 charge and discharge cycles showing a stable rechargeable ability. From a variety of cellulosic materials, the method can be used to produce Ti 3 C 2 T x composite fabrics which are promising candidates of energy storage, electromagnetic shielding, sensing, absorbing, electrocatalysis, etc. [ABSTRACT FROM AUTHOR]