High-performance different shape carbon decorated asteroidea-like cobalt diselenide electrode for energy storage device

Abstract

Presently, the selenides-based transition metal appears to be one of the encouraging materials utilized in energy conservation, and storage applications. In this report, we presented the pure cobalt diselenide (CoSe2) and its composite with different shaped carbon using the one-step hydrothermal method. The CoSe2 with activated carbon composite exhibited the highest electrochemical performance among all prepared samples. It depicts retention of capacitance at around 80 % for 5000 cycles. A symmetric device prototype cell has been designed using a CoSe2/activated carbon composite electrode which displays the highest specific energy and power density as 83 Wh kg−1 at 1622 W kg−1. The maximum specific capacitance displayed by it is 886 F g−1 for a constant 10 mV s−1 Further, a possible charge storage mechanism related to the fabricated cell is proposed. The fabricated device application in practical life has been tested via a glowing panel containing 17 light-emitting diodes (LEDs) and its performance remains the same after six months too. The noteworthy improved capacity, good cycling stability, and high specific energy for the CoSe2 with activated carbon composite material is possibly considered a potential candidate for energy storage devices, and portable electronics.