Rational design of a setaria-like NiTe₂/MoS₂ semi-coherent heterogeneous interface for enhancing diffusion kinetics...

Constructing unique heterostructures is a highly effective approach for enhancing the K⁺ storage capability of transition metal selenides. Such structures generate internal electric fields that significantly reduce the charge transfer activation energy. However, achieving a flawless interfacial region that maintains the optimal energy level gradient and degree of lattice matching remains a considerable challenge. In this study, we synthesised Setaria-like NiTe₂/MoS₂@C heterogeneous interfaces at which three-dimensional MoS₂ nanosheets are evenly embedded in NiTe₂ nanorods to form stabilised heterojunctions. The NiTe₂/MoS₂ heterojunctions display distinctive electronic configurations and several active sites owing to their low lattice misfits (δ = 13 %), strong electric fields, and uniform carbon shells. A NiTe₂/MoS₂@C anode in a potassium-ion battery (KIB) exhibited an impressive reversible capacity of 125.8 mAh/g after 1000 cycles at a rate of 500 mA g^-1 and a stable reversible capacity of 111.7 mAh/g even after 3000 cycles at 1000 mA g^-1. Even the NiTe₂/MoS₂@C//perylene tetracarboxylic dianhydride full battery configuration maintained a significant reversible capacity of 92.4 mAh/g after 100 cycles at 200 mA g^-1, highlighting its considerable potential for application in KIBs. Calculations further revealed that the well-designed NiTe₂/MoS₂ heterojunction significantly promotes K⁺ ion diffusion.