A sandwich-structured flexible triboelectric nanogenerator self-charging system for energy harvesting and human motion monitoring

The self-powered system based on supercapacitor (SC) and triboelectric nanogenerator (TENG) has emerged as a potential sustainable energy solution and exhibits great promise in the development of portable smart electronic devices. Herein, a novel self-charging system is assembled with Ni1Co2Al@carbon cloth (CC)@silica gel-based TENG (NCA-TENG) and Al-MnO2@CC cathode-based quasi-solid-state supercapacitor (AA-SC) for energy collection, storage, and human movement monitoring. For the NCA-TENG, the silica gel serves as the negative friction layer to form a triboelectric pair with the skin, and the Ni1Co2Al@CC acts as the electrode, which reveals a high output performance possessing an open-circuit voltage of 270 V and a short-circuit current of 18 mu A. For the energy storage unit, the quasi-solid-state supercapacitor is assembled with the Al-doped MnO2@CC cathode and the activated carbon (ACC)@CC anode, demonstrating a capacitance of 314.17 mF/cm2 and good stability of 83 % retention rate after 3000 cycles. Furthermore, relying on the outstanding electrical output, NCA-TENG can successfully charge the energy storage units of AA-SC, indicating its integration of energy harvesting and storage. In addition, the self-powered system demonstrates a high potential in real-time response to human body motions, which can function as a self-charging body movement monitoring sensor. This work manifests the broad application prospects of the self-charging system in wearable technology.