Improved triboelectric nanogenerator by as-prepared lithium niobate for energy harvesting and sensing applications

Triboelectric nanogenerators (TENGs) have garnered significant research interest due to their ability to harvest mechanical energy efficiently. In this study, we report a TENG composed of polydimethylsiloxane (PDMS) and polyvinyl alcohol (PVA) as triboelectric layers. To enhance charge generation in the PDMS composite polymer, we incorporated lithium niobate (LiNbO₃) nanoparticles, leveraging their piezoelectric and ferroelectric properties. The LiNbO₃ nanoparticles were synthesized using a solid-state reaction method, resulting in two distinct phases: triclinic LiNbO₃ and monoclinic LiNb₃O₈. Various weight percentages of LiNbO₃ and LiNb₃O₈ nanoparticles were added to the PDMS matrix to optimize power generation. The maximum open-circuit voltage (V_OC) and short-circuit current (I_sc) were achieved with 7 wt% LiNbO₃ and LiNb₃O₈ added to the PDMS. The corresponding values were approximately 2.54 V and 10.24 V, and 170 nA and 2 μA, respectively. Furthermore, the fabricated TENG was employed to harvest energy from raindrops and human body movement. Using tap water as a raindrop source, the maximum V_OC was found to be approximately 2.25 V at a water pressure of 8 N/cm². The TENG also demonstrated remarkable capability in sensing human physiological motions, such as during regular walking, running, and jumping.