Humidity-Resistant Triboelectric Nanogenerator Based on a Swelling-Resistant and Antiwear PAN/PVA-CaCl₂ Composite Film for Seawater Desalination

Atmospheric moisture accelerates the triboelectric charge transport and dissipation in the triboelectric nanogenerator (TENG). However, the output of polyvinyl alcohol (PVA)-based humidity-resistant TENG is still limited under high humidity and suffers from the swelling problem in practical application. In this paper, a swelling- and humidity-resistant high-performance TENG using a polyacrylonitrile/polyvinyl alcohol-calcium chloride (PAN/PVA-CaCl2) composite film (PPCa-TENG) is designed for seawater desalination. The PAN/PVA-CaCl2 composite films exhibit superior water uptake speed, swelling resistance, and mechanical and tribological properties compared with other prepared membranes at high relative humidity (RH). The maximum short-circuit current (I-sc) and output voltage (V-o) of the PPCa-TENG can reach 52.04 mu A and 941 V at 75% RH, respectively, with increasing the power of PVA-based TENG by about 17.39 times. The Kelvin probe force microscopy (KPFM) results suggest that the PAN/PVA-CaCl2 composite film demonstrates a higher tribopositivity. Furthermore, the PPCa-TENG is applied as an effective, economical power source for seawater desalination, with an energy consumption of only 0.19 kWh m(-3). This number is remarkably lower than that of desalination powered by conventional direct-current power supplies reported in previous work. This paper provides a feasible, effective method for the design of the TENG with high performance under high-humidity conditions.