Multiple transition metals modulated hierarchical networks for high performance of metal-ion batteries

Prussian blue analogue (PBA) supported transition metals Fe and Co doped NiS is confined within carbon nano-cubes via an in-sphere sulfuration to form (FeCo-NiS@NC), which can be served as anodes for both LIBs and SIBs with excellent capacity, fast rate performance and outstanding cycling stability due to promoted conductivity and the adjusted voids to buffer volume change under battery operations. Searching anodes with excellent electrochemical performance has been in great demand for rechargeable metal ion batteries. In this contribution, Fe/Co co-doped NiS with N-based carbon (FeCo-NiS@NC) derived from trimetallic Prussian blue analogue is designed and synthesized. The composition can be easily adjusted and modulated by multi-metals. In addition, the well-designed carbon nanocubes effectively promote electronic conductivity and buffer the volume change upon charge and discharge cycling, resulting in good capacity and long-term cycle life for both lithium-ion batteries and sodium-ion batteries, with capacities of 1018 mAh g −1 (vs. Li/Li + ) and 454 mAh g −1 (vs. Na/Na + ), respectively, after 100 cycles. Kinetics studies indicate that the electrochemical behaviors are manipulated by both diffusion and pseudocapacitance processes. These strategies would open new opportunities and potention for novel energy storage.