Comparison of electrochemical properties of bismuth oxide/sulfide core@shell and heterostructure composites as anode material for lithium-ion batteries

Core–shell (Bi 2 O 3 @Bi 2 S 3 ) and heterostructure composites of bismuth oxide (Bi 2 O 3 ) and bismuth sulfide (Bi 2 S 3 ) have been produced using wet chemical method. The performance of both materials as anode material for lithium-ion battery (LIB) have been evaluated. The Bi 2 S 3 /Bi 2 O 3 heterostructure composite exhibited superior electrochemical performance compared to Bi 2 O 3 @Bi 2 S 3 core–shell for LIB. It demonstrated high coulombic efficiency, high capacity, superior capacity retention, excellent rate capability, and long cycle stability. Higher capacity of ~ 530 mAh g −1 was obtained for Bi 2 O 3 /Bi 2 S 3 heterostructure composite compared to ~ 335 mAh g −1 for Bi 2 O 3 @Bi 2 S 3 core–shell anode after a run of 500 cycles. Polysulfide shuttling is more prevalent in the core–shell Bi 2 O 3 @Bi 2 S 3 in which the outer shell is predominantly Bi 2 S 3 compared to Bi 2 O 3 /Bi 2 S 3 heterostructure composite. As sodium-ion battery anode, the Bi 2 O 3 /Bi 2 S 3 heterostructure composite delivers a reversible discharge capacity of 421 mAh g −1 at current rate of 100 mA g −1 after 200 cycles. Materials characterization and electrochemical analysis revealed that enhanced energy storage properties of Bi 2 O 3 /Bi 2 S 3 heterostructure composites are accredited to the synergistic effect of upgraded charge transfer in the heterostructures and reduced polysulfide leaching compared to the core–shell structures. The results showed that Bi 2 O 3 /Bi 2 S 3 heterostructure composites have high potential for application as advanced anodes for Li-ion and Na-ion storage.