Yolk-Shell MnSe/ZnSe Heterostructures with Selenium Vacancies Encapsulated in Carbontubes for High-Efficiency Sodium/Potassium Storage.

The pursuit of high-performance batteries has propelled the investigation into advanced materials and design methodologies. Herein, the yolk-shell MnSe/ZnSe heterojunction encapsulated in hollow carbontubes (MnSe/ZnSe@HCTs) is prepared as a prospective electrode material for sodium/potassium batteries. The band structure in the heterojunction is methodically adjusted and regulated by intentionally utilizing Mn with unpaired electrons in the 3d orbital. The ZnSe shell confer effectively mitigates volumetric expansion challenges inherent in ions insertion/extraction processes and 1D carbontubular conductive substrate avert the aggregation of MnSe/ZnSe nanoparticles. Concurrently, the heterojunctions implantation induces sublattice distortion and charge redistribution, enriching active sites and regulating band structure. The selenium vacancies within these heterojunctions contribute to the provision of abundant active sites, thereby promoting efficient ions insertion/extraction. In sodium-ion batteries (SIBs), MnSe/ZnSe@HCTs present a superior capacity of 475 mA hg ^-1 at 0.1 A g ^-1 and sustains a capacity of 408.5 mAh g ^-1 even after 1000 cycles. In potassium-ion batteries (KIBs), MnSe/ZnSe@HCTs deliver a higher specific capacity of 422 mAh g ^-1 at a current density of 0.1 A g ^-1 and maintain a high coulombic efficiency of 99% after 1000 cycles. The yolk-shell structured MnSe/ZnSe heterojunction demonstrates excellent electrode properties for high-performance sodium/potassium batteries, holding significant promise for future energy storage applications.
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