Renewable energy storage using hydrogen produced from seawater membrane-less electrolysis powered by triboelectric nanogenerators

Abstract

Utilization of widely available seawater for hydrogen generation using robust electrolysis methods can provide sustainable solutions to energy carriers. Sea waves at the same time provide abundant renewable energy that can produce the electricity required for seawater electrolysis. This work presents a novel design for a self-powered hydrogen generation based on membrane-less seawater electrolysis integrated with spring-assisted spherical triboelectric nanogenerators. To streamline fabrication and minimize maintenance expenses, water electrolysis is conducted in a membrane-less electrochemical cell reactor. Employing a mathematical model, the system's performance is analyzed across different catalysts, electrolytes, and operational temperatures. The modeling outcomes indicate that elevating the cell's temperature can lower the necessary potential, enhancing overall electrochemical cell efficiency and decreasing capacitor charging duration. The voltage required for the cell to reach 100 mA cm−2 in the seawater decreases from 2.4 V to 1.9 V as the cell temperature increase from 25 °C to 70 °C. This is due to the decline in the hydrogen and oxygen evolution reaction overpotentials for NPNNS and Ti supported PtPd from 351 mV to 246 mV and 568 mV–394 mV, respectively. Furthermore, increase in the temperature results in an additional 19 % improvement in cell efficiency from 78 % to 97 % and producing hydrogen per cycle during electrolysis of seawater increase from 0.015 μmole to 0.020 μmole.