Efficient Ni2V2O7 catalyst for high-performance Li–S batteries

Abstract

Although Li–S batteries have a high theoretical capacity, their application are significantly hindered by the complex shuttle effect of polysulfides. To address the issues, in this paper, Ni₂V₂O₇ prepared by a simple method is proposed as an efficient catalyst for S cathodes. Ni₂V₂O₇ composed of Ni–O octahedra and V–O tetrahedra has a specific electronic structure. The Ni and V atoms interacted, enabling a fast kinetics of polysulfide redox. Moreover, Ni₂V₂O₇ contains metal sites (Ni and V) and oxygen vacancies, providing a high adsorption capacity and abundant active sites for polysulfide redox. Therefore, Li–S batteries consisting of Ni₂V₂O₇-based cathodes exhibit an excellent cycling stability with a capacity of 1061 mAh g⁻¹ and capacity retention of 87.6% after 150 cycles at 0.2 C. Moreover, at 1 C rate, the batteries exhibit a capacity of 706 mAh g⁻¹ after 300 cycles with a minimal capacity decay of only 0.08% per cycle.