A novel 2D VC₄ as a promising Na-host material for Na-ion batteries: computational insights

The rapid growth of technologies has influenced our daily lives to build efficient energy storage systems for various electric vehicles and portable electronic devices. The abundant reserves, low cost, and low toxicity of sodium-ion batteries (SIBs) make them one of the most promising next-generation energy storage technologies. However, limited anode materials hinder their further development. Here, we predict a 2D VC4 monolayer as the Na host material for SIBs. Based on our theoretical analysis, it is stable dynamically as well as thermally. As a Na host material, the VC4 anode is found to have a low open-circuit voltage (0.51 V) and a high Na storage capacity of 1353 mA h g(-1). Also, the Bader charge technique reveals charge transfer from Na to VC4 and thus verifies the electrochemical reaction between Na and the host. Eventually, we inspect the low activation barrier for Na migration on VC4 (0.32 eV), revealing rapid charging/discharging rates. These fascinating results of the current study provide a theoretical and technical basis for the advancement of SIBs.