LAUSR

Abstract Sodium-ion batteries have become an arresting battery system for energy storage due to the rich sodium resources, while the current anode materials greatly restrict the rate and cycling properties of sodium-ion batteries. Herein, we report a novel ternary B2O3/BC2O/C nanosheets with mesoporous structure, where the ultrafine PbTe nanodots are uniformly embedded (PbTe/BC). These existing boracic phases remarkably improve the electrical conductivity of carbon matrix, even provide ample structural defects and more redox active sites to achieve highly capacitive and efficient sodium storage. The ternary nanosheets have a strong binding affinity to sodium and the boracic phases participate in the sodiation/desodiation reactions that promote the electrochemical activity for highly efficient sodium storage. The intrinsic cation vacancies of PbTe nanodots contribute extra active sites and channels to the ultrafast transport of sodium ions. The surface-controlled capacitive charge as a great contributor to sodium storage greatly favors ultrafast sodium storage. As a result, PbTe/BC anode exhibits the reversible sodium storage capacity of >1000 mAh g−1 at 0.1 A g−1, excellent rate capability of 230 mAh g−1 and high capacity retention of 90.1% after 500 cycles at 10 A g−1. These results demonstrated a new way to design boron/carbon anodes for future sodium-ion batteries.