Double‐Shelled NiO‐NiCo2O4 Heterostructure@Carbon Hollow Nanocages as an Efficient Sulfur Host for Advanced Lithium–Sulfur Batteries

Abstract Double‐shelled NiO‐NiCo 2 O 4 heterostructure@carbon hollow nanocages as efficient sulfur hosts are synthesized to overcome the barriers of lithium–sulfur (Li–S) batteries simultaneously. The double‐shelled nanocages can prevent the diffusion of lithium polysulfides (LiPSs) effectively. NiO‐NiCo 2 O 4 heterostructure is able to promote polysulfide conversion reactions. Furthermore, the thin carbon layer outside can improve the electrical conductivity during cycling. Besides, such unique double‐shelled hollow nanocage architecture can also accommodate the volumetric effect of sulfur upon cycling. As a result, the prepared S/NiO‐NiCo 2 O 4 @carbon (C) electrode exhibits good rate capacities and stable cycling life up to 500 cycles at 0.5 C with a very low capacity decay rate of only ≈0.059% per cycle.