Construction of porous-carbon supported core-shell SnO2@BaTiO3 nanosphere heterostructures as anode for high-performance sodium-ion battery

Sodium-ion batteries (SIBs) have emerged as highly promising and economically viable alternatives to lithium-ion batteries (LIBs) for large-scale energy storage systems and light electric vehicles. Optimizing anode materials is crucial for enhancing the energy density and cycling stability of SIBs. In this study, a coherent SnO 2 -coated BaTiO 3 nanosphere composite with carbon package dispersed inside porous carbon network (PC/C@SnO 2 @BaTiO 3 ) is introduced as SIBs anode, which was synthesized by two-step hydrothermal method and calcination process with NaCl template. The piezoelectric effect of BaTiO 3 during charge-discharge process can raise electron conductivity and ion diffusion rate in the as-formed composite. The porous carbon network outside not only strengthens the structure of the anode material but also increases the contact area between the electrode and the electrolyte with the improving conductivity and Na + diffusion rate, thereby enhancing the kinetic and electrochemical properties of the active material. After 300 cycles at 0.1 A g −1 , the PC/C@SnO 2 @BaTiO 3 composite retains a capacity of 372.8 mAh g −1 from the initial 454.5 mAh g −1 , and can still exhibit outstanding rate characteristics with a capacity of 176.3 mAh g −1 at 2 A g −1 after 300 cycles. The results show the PC/C@SnO 2 @BaTiO 3 composite has great promise as anode-active material for SIBs. • Novel PC/C@SnO 2 @BaTiO 3 composite as SIBs anode material. • Carbon encapsulation enhances the structural stability of composite materials. • BaTiO 3 piezoelectricity enhances ion and electron transport in the composite. • PC/C@SnO 2 @BaTiO 3 composite exhibits excellent cycling stability and rate performance.