Engineering of electrodes with 2D Ti₃C₂T_x-MXene sheets and chloride salt for robust and flexible high electrical power triboelectric nanogenerator

This article focuses on the development of triboelectric nanogenerator (TENG) by utilizing advanced 2D nano-materials with innovative design and easy fabrication method to achieve durable TENG with high-power density and improved cycling performance. Herein, we fabricated a layer-by-layer stacked vertical contact-separation (CS) mode TENG. In this unique design, we incorporated a thin film of micron-sized Ti3C2Tx-MXene ultrathin sheets (TMSs) into a polyethylene terephthalate (PET) based tribo-negative electrode. A tribo-positive layer was prepared by integrating an optimized amount of NaCl into a polyvinyl alcohol (PVA) matrix. After optimization of both triboelectric layers, the optimized TMS-TENG showed an open-circuit voltage (V-oc) similar to 390 V, short-circuit current (I-sc) similar to 96 mu A, and power density of 6.66 W center dot m(-2). The boosted performance is due to the synergistic effect of TMSs, used as a charge trapping layer on the electronegative side, and the impact of an NaCl:PVA impregnated layer on the electropositive side of the TENG. The ultrathin-layered structures of sandwiched TMS film serve bifunctionally as a charge accumulation and charge trapping entity simultaneously, increasing the charge separation due to high dielectric constant, and thus increasing the overall output power of the fabricated TENG. The prepared TMS-TENG was tested as a pressure sensor to monitor different sensitive physiological movements of the human body. Further applications of the designed TMS-TENGs have been revealed by powering more than 500 LEDs, an electronic calulator, and swiftly charging micro-capacitors by utilizing direct output power. By engineering electrodes, we can gain insight into the specific role that TMSs play in enhancing the performance of TENGs. This research provides a new avenue for designing self-powered pressure/motion sensors in robotics and harvesting biomechanical energy as electrical energy for sustainable electronics.