Nano potassium phosphotungstate spheres/sulfur composites as cathode for Li-S batteries

Herein, a new strategy of using polyoxometalates (K3PW12O40) to stabilize sulfur was introduced for the first time for Li-S batteries. The as prepared K3PW12O40 spheres/S electrode shows a initial discharge capacity of 1281.0 mAh g−1 with a good cycling stability at a rate of 0.1 C. In particular, the K3PW12O40/S electrode exhibits an initial specific capacity of 810.0 mAh g−1 at a high current rate of 2 C, and remains 560.4 mAh g−1 after 250 cycles. The excellent performances are attributed to the significant roles that K3PW12O40 host played during the charge/discharge process.