Engineering ion diffusion highway in robust bonding interface endows high-rate and durable energy storage

Transition metal compounds (TMCs) with high theoretical capacity have been considered as promising battery-type electrode materials for hybrid supercapacitors (HSCs), yet they often encounter low rate capability and poor cycling performance. Herein, the NiCoSe₂ nanoparticles strongly bonded on the N-doped SiC nanowires (N-S@b-NCS) with Ni/Co–N bonds in their interfaces are firstly constructed via an electrodeposition method. Theoretical calculations indicate that the unique interfacial chemical bonding with built-in electric field can not only significantly facilitate charge transfer and reduce the ion diffusion barrier, but also effectively guarantee structure integration induced by the timely release of stress concentration. Benefiting from the advantages, the achieved N-S@b-NCS exhibits high specific capacity of 254.4 mAh·g⁻¹ at 1 A·g⁻¹ and still retains 183.2 mAh·g⁻¹ even at 100 A·g⁻¹, as well as outstanding cycling stability with ~ 90% capacity retention after 30,000 cycles. Additionally, a hybrid supercapacitor assembled by the obtained N-S@b-NCS displays a high energy density of 71.4 Wh·kg⁻¹ at 16 kW·kg⁻¹ and excellent durability. This work provides a creative strategy for how to construct the bonded interface with ions diffusion highway and long-term cycling stability, which can greatly push the large-scale applications of the TMCs.