Dual-functional electrocatalytic cathode for hybridizing reaction mechanisms to enhance energy efficiency in seawater batteries

Seawater batteries (SWBs) as next-generation devices have garnered considerable attention due to their merits including cost-effectiveness, environmental friendliness, and safety. However, poor energy efficiency (EE) of SWBs impedes their practical application. Herein, we report advanced electrocatalytic active cathode material capable of simultaneously activating two different redox reactions: the oxygen evolution/oxygen reduction reaction (OER/ORR) and Cl-involved conversion reaction, thereby enhancing the EE of SWBs. In pursuit of an effective electrocatalytic active material for a hybrid energy storage mechanism, metallic Ag (x) nanoparticles decorated La_1-xNiO₃ perovskites (ALNO-x) were utilized. Within ALNO-x, LNO improves electrocatalytic kinetics and acts as an effective OER/ORR electrocatalyst, while Ag nanoparticles facilitate the Ag/AgCl conversion reaction and help to reduce overpotential. To prove it, we have investigated the charge/discharge behavior of SWB according to the contents of Ag in ALNO-x cathode materials. As a result, an increase in the Ag content within ALNO-x cathode materials leads to a heightened EE, suggesting the significant potential of multifunctional electrocatalysts for SWBs featuring a hybrid energy storage mechanism.