High stability rotary solid-liquid triboelectric nanogenerator for ionic liquid detection

Triboelectric nanogenerators (TENG) have been widely used in various fields as an efficient energy harvesting device. Rotary TENG can harvest energy in the form of water energy, wind energy, and so on. However, almost all of the rotary TENGs reported so far are solid-solid contacts. The solid-solid TENG is prone to friction loss during operation, which results in the service life and stability not being adequately guaranteed. In this paper, a rotary solid-liquid TENG (RSL-TENG) is proposed to solve the above problems. The results show that RSL-TENG has high stability after up to 50 h of continuous 600,000 cycles of operation with no decay of the transferred charge after 50 h. The charge density of RSL-TENG is as high as 52.5 μC/m² when using fluorinated ethylene propylene (FEP) film and 80 mL of purified water. Compared with the reported solid-liquid TENG (SL-TENG), the charge density obtained in this paper is relatively high. The output voltage, short-circuit current, and transferred charge of the RSL-TENG are 246.6 V, 3.9 μA, and 283.4 nC, respectively. After testing with ions commonly found in wastewater, RSL-TENG is found to have output performance with different characteristics. The output voltage, short-circuit current, and transferred charge of the copper ionic solution with the best output performance are 195.8 V, 3.3 μA, and 265.2 nC, respectively. The experimental results show that the liquid type has a certain influence on the output performance of RSL-TENG, which can be used to distinguish the type of ionic solution. © 2025 Elsevier Ltd.