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
maximumshort-circuit current (Isc) and output voltage (Vo) of the PPCa-TENG
can reach 52.04 μA 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.