Effect of aqueous electrolyte on pseudocapacitive behavior of chemically synthesized La2S3 electrode

Lanthanum sulfide electrode (La2S3) is prepared by a low cost, simple and room temperature chemical route for energy storage. The surface morphology of La2S3 film is revealed through field emission scanning electron microscopy. For the energy storage purpose, the pseudocapacitive behavior of La2S3 electrode is studied in 1 M aqueous Na2SO4 and 1 M KOH electrolytes. La2S3 electrode achieved maximum specific capacitance of 358 F g−1 at 5 mV s−1 scan rate with 78% electrochemical cyclic stability over 1000 cycles in 1 M Na2SO4 electrolyte. The galvanostatic charge–discharge study demonstrated the energy density of 35 Wh kg−1 at power density of 1.26 kW kg−1. The electrochemical impedance study showed field assisted charge transfer process with relaxation time of 32 ms in 1 M Na2SO4 electrolyte ensuring fast redox reaction.