Boosting ion diffusion kinetics of Fe2O3/MoC@NG via heterointerface engineering and pseudocapacitance behavior: An alternative high-rate anode for high-capacity lithium dual-ion batteries

Lithium dual-ion batteries (Li-DIBs) technology is expected to become a leader in replacing lithium-ion batteries (LIBs) to carry out high energy/power density energy storage devices. Unfortunately, the sluggish electrochemical reaction kinetics of anode materials critically restricts their practical development. Here, a Li-DIBs is proposed by using a three-dimensional (3D) structure composed of Fe2O3/MoC heterostructure nanoparticals embedded in a hierarchical mesoporous nitrogen-doped reduction graphene oxide (Fe2O3/MoC@NG) as the anode, which has low Li+ ion diffusion barrier (0.098 eV), high Li+ ion diffusion coefficient (4.99 x 10-11 cm2 s-1) and remarkable rate property (879.2 mA h g-1 at 10 A g-1), and choosing nano-graphite as the cathode. Originating from the respective strengths of Fe2O3/MoC@NG anode and the nano-graphite cathode, the asconstructed Li-DIBs full battery displays high reversible capacity and prominent rate property (103.9 mA h g-1 at 0.05 A g-1 and 48.9 mA h g-1 at 2 A g-1). Specifically, taking advantage of density functional theory (DFT) calculations, the exact paths of PF6- ion intercalation into graphite cathode and Li+ ion diffusion into Fe2O3/MoC@NG anode is obtained, namely PF6- ion transmits along the (002) face of nano-graphite and Li+ ion diffuses along the heterointerface of Fe2O3/MoC@NG.