Efficient Ni2 V2 O7 catalyst for high-performance Li-S batteries.

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, Ni² V₂ O₇ prepared by a simple method is proposed as an efficient catalyst for S cathodes. Ni² V₂ O₇ 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, Ni² V₂ O₇ 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 Ni² V₂ O₇ -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. [ABSTRACT FROM AUTHOR]