All‐MXene Cotton‐Based Supercapacitor‐Powered Human Body Thermal Management System

Abstract Personal body thermal management (PBTM) has shown great potential in the application of artificial skin, smart clothing, and health care for the rapidly developed flexible electronics and “Internet of Things”. However, the heating efficiencies of the previously reported PBTM systems are relatively low with low response rate and high driving voltage, which are not satisfying for wearable devices. Here, we report a MXene‐coated cotton fabric (MCF)‐based PBTM system, which shows good water vapor permeability, air permeability, wear resistance, and wash stability. The optimal MCF shows high electron conductivity of 197 mS cm −2 and high heating efficiency, which could be heated up to 100 °C within 10 s under the low applied potential of 3 V. By applying a low voltage of 1.5 V, the MCF exhibited a high temperature of 45 °C, meeting the requirement of human body. In addition, serving as the electrode material of supercapacitors, the MCF exhibits high areal specific capacitance of 208 mF cm −2 at a scan rate of 5 mV s −1 . The symmetric supercapacitor device could provide a high energy density of 2 μWh cm −2 and power density of 5.3 mW cm −2 . Using the MCF‐based symmetric supercapacitor as the power source, the MCF could be heated and employed as a supercapacitor‐powered PBTM system, which indicates its significant potential for the application of wearable PBTM and beyond.