Structural and Interfacial Manipulation of Multifunctional Skeletons Enabled Shuttling-Free and Dendrite-Free Li-S Full Batteries

Li-S batteries are regarded as promising devices for energy storage systems owing to high energy density, low cost, and environmental friendliness. However, challenges of polysulfides shuttling in sulfur cathode and dendrite growth of lithium anode severely hinder the practical application. Developing advanced skeletons simultaneously regulating the cathode and anode is significant and challenging. Hence, a novel and scalable strategy combining spray drying and topological nitriding is proposed, and hierarchically assembled rGO hollow microspheres encapsulated highly porous nanospheres consisted of ultrafine Nb4N5-Nb2O5 or Nb4N5 nanoparticles as multifunctional skeletons for S and Li are designed. In such unique architecture, a 3D highly porous structure provides abundant void space for loading of S and Li, and accommodates volume change during cycling. Moreover, Nb4N5-Nb2O5 heterostructured interface promotes adsorption-conversion process of polysulfides, while strong lithophilic Nb4N5 induces the selective infiltration of Li into the void of the skeleton and regulates the uniform deposition and growth. More interestingly, in situ generated Li3N@Nb ion/electron conducting interfaces induced by the reaction of Nb4N5 and Li reduce the nucleation overpotential and induce selective deposition of Li into the cavity. Consequently, the Li-S full cell exhibits superior cycling stability and impressive rate performance with a low capacity ratio of negative/positive. Hierarchically assembled Nb-based micro-nanospheres are rationally designed and masterly synthesized via a structural and interfacial manipulation strategy and employed as multifunctional skeletons for cathode and anode of Li-S fell cells. Benefiting from the unique structure, the polysulfides shuttling in sulfur cathode and dendrite growth of lithium anode can be effectively regulated simultaneously. image