Heterostructured Bi(2)O(3)@rGO Anode for Electrochemical Sodium Storage

Bismuth oxide (Bi(2)O(3)) is an auspicious anode material for sodium-ion batteries owing to its high theoretical capacity and abundant Bi resources. However, the poor electronic conductivity and huge volume expansion of Bi(2)O(3) during cycling lead to the low coulombic efficiency and unstable cycling stability. Aiming to suppress these issues, we use highly conductive reduced graphene oxide (rGO) as a continuous skeleton to fabricate a Bi(2)O(3)@rGO heterostructure. It exhibits high reversibility and stability for electrochemical sodium storage by delivering a reversible capacity of 161 mAh g(−1) after 100 cycles at 50 mA g(−1), which completely outperforms Bi(2)O(3) (43 mAh g(−1)). In addition, the coulombic efficiency of the heterostructure stabilizes at >90% upon only 3 cycles. The results can be attributed to the dual function of rGO in supporting Bi(2)O(3) nanoparticles and providing conductive pathways to fasten electron transport.