Advanced energy harvesting from low-frequency ocean waves for lithium-ion battery applications

Abstract

The low root mean square (RMS) current density generated by triboelectric nanogenerators (TENGs) has significantly hindered their effectiveness in charging lithium batteries. In response, we present a universal energy storage strategy for TENGs specifically designed for real marine environments, facilitating effective charging of lithium batteries for the first time. By integrating multiple grating electrodes and a ternary electrification architecture with an opposite-charge compensation mechanism, we increased the RMS current density of TENGs to 57.19 ± 0.23 mA m⁻² Hz⁻¹. Additionally, we designed a lithium polymer charge management module that further boosts the RMS current density to 0.86 ± 0.02 A m⁻² Hz⁻¹, a 14-fold improvement, enabling direct charging of 30 mA h and 40 mA h lithium batteries in 2.33 ± 0.05 h and 3.73 ± 0.14 h, respectively. Building on this foundation, we developed a self-powered remote (0.65 nautical miles) monitoring sensor network tailored for marine applications, enabling the initial use of Internet of Things technology in a marine environment.