多重限域几何中的化学键助力 Bi2Se3 基转换-合金负 极材料实现优异的钠离子储存

Conversion-alloying-based materials have been regarded as potential anode electrodes for low-cost sodium-ion batteries (SIBs), but their applications are limited owing to the large volume variation and poor electrochemical kinetics. In this study, Bi2Se3 nanoflowers assembled by ultra-thin na-nosheets, vertically anchored on reduced graphene oxide (rGO) via strong chemical bonding of C–O–Bi, encapsulated in N-doped C nanolayer (Bi2Se3@rGO@NC), constructed anodes Na-ion storage. The physico-chemical encapsulation geometry is conductive acquiring excellent electrode integrity accommodating lattice strain, well boosting fast kinetics process dispelling band gap decreasing diffusion barrier. Bi-ion used a redox site insertion/extraction conversion-alloying dual-mechanism with 12-electron transport per formula (Bi2Se3 + 12Na+ 12e− ⟷ 2Na3Bi 3Na2Se). Thus, high initial charge capacity 288.4 mA h g−1 at 50 g−1, cycling stability an ultra-long lifespan over 1000 cycles, good rate property (119.9 5.0 A g−1) can be achieved Bi2Se3@rGO@NC. This study may open up systematic research shed insights into illumination reaction mechanism SIBs.