High performance of co-doped V2O5 cathode material in V2O5-saturated (NH4)2SO4 electrolyte for ammonium ion battery

Abstract

Aqueous ammonium-ion batteries are eco-friendly and abundant systems that exhibit diffusion. These systems have been reported in recent years. Vanadium pentoxide (V2O5) with a layered structure is a good electrode material. A Co-doped V2O5 cathode characterized by good reversibility and rate performance was prepared using the hydrothermal method to improve the ionic diffusion kinetics characterizing the systems and address the issue of low conductivity of V2O5. Saturated V2O5 (NH4)2SO4 solution was used as the electrolyte to fabricate the ammonium ion battery. Pure V2O5 and V2O5 samples with varying levels of cobalt dopants, V2O5-2Co samples doped with 2 % cobalt exhibited a maximum capacity of 172 mAh g–1 and coulombic efficiency of 61.6 % after 500 cycles at the current density of 1.0 A g–1. This indicated good cyclic reversibility. The high energy density was established to be ~152 Wh kg–1, and the capacity retention rate was 49.2 % after 1000 cycles. These results indicate that Co-doped V2O5 nanoparticles can potentially help in improving the electronic conductivity of the system and provide an effective pathway for rapid electron transfer.