Here, polypyrrole@Ni3S2 (PPy@Ni3S2) core-shell nano-heterostructures (CSNHs) as the positive electrode are engineered by electrochemically depositing Ni3S2 nanosheets on the surface of PPy nanowires that are directly electrochemically polymerized on Ni foam. Meanwhile, N-doped carbon nanotubes (N-CNTs)/MoO2 nano-heterostructures (NHs) as the negative electrode are also built by tightly anchoring MoO2 nanoparticles on the surface of N-CNTs through a C–O–Mo bridge. By promoting the surface Faradaic reaction kinetics that are contributed by these two engineered NHs, PPy@Ni3S2 positive electrode demonstrates improved electrochemical performances, i.e., 1841 (1307) F g−1 at 3 (30) A g−1 and 93% capacitance retention over 5000 cycles at 15 A g−1. Likewise, N-CNTs/MoO2 negative electrode also exhibits a specific capacitance of up to 489 F g−1 at 1 A g−1, 69% capacitance retention at 20 A g−1 as well as 95% capacitance retention after 5000 cycles at 10 A g−1. Moreover, the assembled PPy@Ni3S2//N-CNTs/MoO2 solid-state asymmetric supercapacitors (ASCs) device delivers an energy density of 71.5 Wh kg−1 at a power density of 801 W kg−1. These results may give insights into the great promise of engineering NHs electrodes based on conductive polymers/metal sulfides and carbon/metal oxides towards high-performance energy storage devices.
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