ZnAl-LDH template-induced formation of ZnO/ZnSe heterostructures on the surface of coal tar pitch-derived carbon for high-efficiency sodium storage

Developing high-performance anodes from low-cost industrial by-products is crucial for advancing sodium-ion batteries. Herein, we report a Zinc Aluminum layered double hydroxides (ZnAl-LDH) template-induced strategy to fabricate ZnO/ZnSe heterojunctions embedded within hierarchical porous carbon derived from coal tar pitch. The LDH serves a dual role as a structural template and pore-forming agent, enabling the in-situ construction of intimately coupled ZnO/ZnSe-C interfaces. The designed ZnO/ZnSe heterostructure features prominent advantages: the heterojunction boosts charge transfer via interfacial contact between the two active components, while the mixed O²⁻/Se²⁻ anion environment, combined with nano-dispersed ZnO/ZnSe and the conductive carbon matrix, effectively enhances reaction kinetics and mitigates volume strain.Consequently, the composite anode delivers a high reversible capacity of 637.5 mAh g⁻¹ at 100 mA g⁻¹ and maintains 259.7 mAh g⁻¹ after 1000 cycles at 5 A g⁻¹. Kinetic analysis attributes the superior rate performance to a dominant capacitive contribution (93.7% at 1.2 mV s⁻¹). A full cell configured with an Na₃V₂(PO4)₃cathode demonstrates practical viability, retaining 147.5 mAh g⁻¹ after 100 cycles. This work highlights the effectiveness of LDH-templated synthesis in constructing advanced heterostructure anodes for efficient sodium storage.