Effect of Fluorine and Copper Ions on Liquid-Solid Triboelectric Nanogenerator

Liquid-solid triboelectric nanogenerator (LS-TENG) harvests energy efficiently while eliminating wear issues associated with solid-solid TENG. However, the effect of ions or charges in the liquid on output performance needs further examination. In this work, the impact of fluorine and copper ions introduced through deionized water with sodium fluoride (DI-NaF) and deionized water with copper sulfate (DI-CuSO₄) solution on the output voltage, charge and current of a tubular LS-TENG with polytetrafluoroethylene (PTFE) and Nylon as solid materials is examined. The results indicate that fluorine and copper ions have opposite effects on PTFE and Nylon LS-TENG's output. The fluorine (F⁻) ions enhance the triboelectric effect and charge transfer in Nylon LS-TENG, increasing output, while they hinder the charge transfer process in PTFE LS-TENG, consequently decreasing its output. Conversely, the copper (Cu²⁺) ions have a positive effect on the output of PTFE LS-TENG and a detrimental effect on Nylon LS-TENG's output. Moreover, the results indicate that LS TENG's output performance depends on the charges of solid and liquid triboelectric materials. Thus, this study provides insights into material-ion interaction in LS-TENG and underscores the importance of triboelectric material selection for optimizing output performance.