Integration of adsorption and catalytic active sites in cobalt iron oxide nanorods for an excellent performance Li–S battery with a wide temperature range

Abstract

Whether Li–S batteries can be worked in a wider temperature range is particularly important. Here, we report micro/nanostructure CoFe₂O₄ rods combining both catalytic sites (Co) and adsorption sites (Fe). Under the synergistic enhancement of these two different sites, the conversion rate of polysulfides in Li–S batteries is greatly accelerated, and the “shuttle effect” is effectively suppressed. When used as the host material for Li–S batteries, the capacity, rate performance and cycling stability are promoted greatly. Most importantly, the cell achieves an excellent electrochemical performance at high temperatures. After 1000 cycles, the Li–S battery using CoFe₂O₄ nanorods as the cathode exhibits a high reversible capacity of about 700 mA h g⁻¹ at a high temperature of 70 °C with a capacity attenuation of less than 0.02% per cycle. Meanwhile, the battery also shows excellent performance at −20 °C owing to the high catalytic activity.