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Zinc-vanadium oxides have been attracting increasing consideration as anode materials for lithium/sodium-ion batteries (LIBs and SIBs) recently. Present applications are hampered by issues, including their inferior electric conductivity and enormous volume variation. Herein, nitrogen-doped carbon wrapped Zn3V3O8 (Zn3V3O8/NC) microspheres composed of abundant nanosheets were developed as an anode material by a self-assembly strategy and subsequent surface decoration. The resulting Zn3V3O8/NC porous hybrid exhibited a high specific capacity, impressive rate capability, and long-term cycling stability for both LIBs and SIBs. Notably, the superior electrochemical properties could be assigned to novel meso/microporous features, hybrid nitrogen-doped carbon, and mixed storage mechanisms.

α-Phase molybdenum trioxide (α-MoO3) is one of the promising anode materials for lithium storage due to its high theoretical capacity and unique intercalation reaction mechanism. Herein, through an efficient step-by-step solvothermal synthesis strategy, multi-layered MoO3 nanosheets are encapsulated by nitrogen-doped carbon (NC) and ultrathin TiO2 double-shells to obtain hierarchical core-shell nanospheres (MoO3@TiO2@NC). The unique nanostructure enables shortening the Li+ diffusion distance, buffer the volume change during the intercalation/deintercalation process, and increase the active sites for the electrochemical reaction. Based on the hierarchical nanostructure and the synergistic effect of each component, the MoO3@TiO2@NC electrode exhibits a high Li+ storage capacity around 979.6 mA h g-1 after 200 cycles at 0.2 A g-1, a stable cycle performance of 800.3 mA h g-1 at 1 A g-1 after 700 cycles and an excellent rate capability of 418.0 mA h g-1 at 5 A g-1. Furthermore, the MoO3@TiO2@NC-based coin-type full cell with a commercial LiNi1/3Mn1/3Co1/3O2 cathode exhibited a good cycling stability at 0.2 A g-1 for 100 cycles (∼190 mA h g-1) and rate capability (134 mA h g-1 at 5 A g-1).

The preparation of an Earth-abundant, highly efficient and durable bifunctional electrocatalyst for water electrolysis is indispensable and in great demand. Herein, a bifunctional catalyst, cobalt–chromium phosphide (Co2Cr1-P) merged with a substrate of three-dimensional graphene foam (3DGF), was reported. The Co2Cr1-P@3DGF composite demonstrates remarkable electrocatalytic activities for the production of hydrogen and oxygen in 1.0 M KOH, which only requires a low overpotential of 118 and 270 mV to afford 10 mA cm−2, respectively. Additionally, when applying Co2Cr1-P@3DGF as a catalytic electrode for alkaline overall water splitting, the demanded cell voltage at 10 mA cm−2 is merely 1.56 V. The superior performance is attributable to the incorporation of the Cr element into CoP and the good conductivity of the 3D graphene network substrate.