Thermo‐Electric Powered High Energy‐Density Hybrid Supercapattery for Driving Overall Water Splitting: A Novel Trifunctional Builder for Self‐Powered Hydrogen Production
Noor Ul Haq Liyakath Ali, Mohamed Sadiq Mohamed Saleem, Arunprasath Sathyaseelan, Vignesh Krishnan, Parthiban Pazhamalai, Anandhan Ayyappan Saj, Sang‐Jae Kim
Abstract
Abstract Integrated electrochemical energy devices with multifunctionality are evolving as an auspicious way to lift up energy technology. However, the challenge is utilizing a single‐electrode material for multifunctional applications is essential to minimize the manpower and overall cost of the system. Herein, a novel and cost‐effective self‐powered aqueous electrochemical energy device (SAEED) is proposed via integrating asymmetric supercapattery (ASD) and water‐splitting (WS) devices utilizing Cu₃Mo₂O₉ (CMD) nanostructures on Ni‐foam (prepared via hydrothermal method) as a trifunctional electrode. First, the Cu 3 Mo 2 O 9 /Ni electrode is examined for the supercapacitor, which shows the faradaic‐type of charge‐storage behavior with a superior specific capacity of 588.88 mAh g −1 . The Cu 3 Mo 2 O 9 ǁgraphene ASD is constructed, which shows high energy storage performance with high device capacitance and energy/power densities and 98% retention capacitance over 5000 cycles. Second, the electrocatalyst behavior of the Cu₃Mo₂O₉/Ni electrode is explored, which reveals impressive HER/OER performance with lower overpotential (HER‐120 mV at 10 mA cm⁻²/OER‐310 mV at 50 mA cm⁻²) values. As a proof‐of‐concept, an SAEED was developed that contains a thermoelectric generator, Cu₃Mo₂O₉ǁgraphene ASD, and a beaker‐type electrolyzer operating at a voltage of 1.58 V to eliminate power loss and intermittent issues for sustainable and uninterrupted production of H₂.