Hollow ZnCo2O4 spheres as matrix for extremely stable lithium-sulfur batteries

Porous hollow cobalt acid zinc (ZnCo2O4) spheres with special surface morphology were synthesized by a simple template-free method. ZnCo2O4 has both impactful adsorption and catalytic ability to lithium polysulfides (LiPSs), in addition, its porous surface greatly increases the number of active. Moreover, the hollow structure enables the ZnCo2O4 spheres to effectively alleviate the expansion of electrode volume during the charging and discharging process applied in lithium-sulfur batteries. The cell with ZnCo2O4 spheres as the host shows a large reversible capacity of 600 mAh g−1 at a high rate of 10C, more importantly, the cycle stability of the lithium-sulfur battery has been greatly improved. At a high current density of 2C, the battery can still release a discharge capacity more than 700 mAh g−1 after 1000 cycles with the capacity decay rate of only 0.015% per cycle.