A wearable self-charging power system integrating micro-supercapacitors and triboelectric nanogenerators with MXene-coated fabric as conductive layer

Self-charging power systems are required for wearable electronic devices to provide energy supply. However, low charging efficiency, complex preparation process and poor wearability limit its application. Herein, a highly efficient, wearable self-charging power system is reported, which consists of a triboelectric nanogenerator (TENG) with fabric coated by MXene paste as conductive layer and micro-supercapacitors (MSCs) with graphene films as electrode. The conductive layer of TENG was prepared by dip-spin coating MXene paste on cotton fabric. The electrodes of MSCs were made by mask-assisted vacuum filtration of graphene solution. The TENG conductive layer and MSCs electrodes with electrolyte were encapsulated by two identical silicone rubbers. The silicon rubbers work as triboelectric layer of the TENG as well as the protective layers of the self-charging power system. The cotton fabrics and silicon rubbers provide strength and flexibility for the system. The MXene paste on cotton fabrics provides excellent energy harvesting ability of TENG due to high conductivity and high charge trapping ability. The TENG can harvest the energy of pressing by a palm. After 147 ​s of continually pressing/releasing cycles, the collected energy can charge 2 series-connected MSCs array to 1.6 ​V, which can power an electronic watch for 25 ​s. Compared with similar systems, this self-charging system was constructed by a simple method from low cost starting materials and exhibits ultra-high performance. The research provides an easy and economical solution of self-charge system for wearable electronic devices. In this paper, a novel self-charging power supply system is designed by integrating TENG and MSC. The conductive layer of TENG is prepared by dip-spin-coating MXene paste, and the MSC electrode is prepared by mask-assisted vacuum filtration of graphene solution. Pressing the TENG with the palm of the hand for 147 ​s, the series MSC array can be charged to 1.6 ​V, which can power an electronic watch for 25 ​s with a high charging efficiency of 0.653 ​V/min. • A novel wearable self-charging power system was fabricated using low-cost materials by spin-coating and mask deposition. • The system was encapsulated by silicone rubber, ensuring the flexibility and durability required for wearable applications. • The system achieves a high charging rate of 0.653 ​V/min, enabling rapid voltage generation.