Nitrogen-doped carbon-support interaction induced d-orbital rearrangement for enhanced sodium-ion storage

Zinc telluride (ZnTe) with high density and low cost is considered as promising anode for sodium-ion batteries. However, ZnTe suffers from continuous capacity degradation owing to the low electronic conductivity, large volume expansion, and high ion-diffusion energy barriers. Herein, the nitrogen-doped carbon confined ZnTe polyhedron heterostructure (ZnTe/NC) is proposed, exploiting its orbital rehybridization and the realignment of energy level to improve storage performance. Systematic ex situ/in situ characterizations and simulations demonstrated that the elaborate ZnTe/NC offers abundant electron/ion transport pathways, accelerates Na⁺ diffusion kinetics, and alleviates huge volume expansion. Notably, the nitrogen-doped carbon-support interaction induced via electron transfer between ZnTe sites and support elevates the energy level of Zn 3d orbital, greatly enhancing ion adsorption capability and reducing the ion diffusion barrier. As a result, the ZnTe/NC anode delivers a high discharge capacity of 470.5 mAh g⁻¹ and long cycling durability over 1000 cycles. This work uncovers that optimizing sodium ion adsorption and diffusion via d-orbital energy level modulation enabled by nitrogen-doped support interaction is an effective method for developing high-performance transition metal telluride anodes for alkali ion storage.