High-energy lithium-ion hybrid supercapacitors composed of hierarchical urchin-like WO/C anodes and MOF-derived polyhedral hollow carbon cathodes.

A lithium-ion hybrid supercapacitor (Li-HSC) comprising a Li-ion battery type anode and an electrochemical double layer capacitance (EDLC) type cathode has attracted much interest because it accomplishes a large energy density without compromising the power density. In this work, hierarchical carbon coated WO (WO/C) with a unique mesoporous structure and metal-organic framework derived nitrogen-doped carbon hollow polyhedra (MOF-NC) are prepared and adopted as the anode and the cathode for Li-HSCs. The hierarchical mesoporous WO/C microspheres assembled by radially oriented WO/C nanorods along the (001) plane enable effective Li insertion, thus exhibit high capacity, excellent rate performance and a long cycling life due to their high Li conductivity, electronic conductivity and structural robustness.

Mesoporous TiO2 Nanocrystals/Graphene as an Efficient Sulfur Host Material for High-Performance Lithium-Sulfur Batteries.

Rechargeable lithium-sulfur (Li-S) batteries are promising in high-energy storage due to the large specific energy density of about 2600 W h kg(-1). However, the low conductivity of sulfur and discharge products as well as polysulfide-shuttle effect between the cathode and anode hamper applications of Li-S batteries. Herein, we describe a novel and efficient S host material consisting of mesoporous TiO2 nanocrystals (NCs) fabricated in situ on reduced graphene oxide (rGO) for Li-S batteries.