Compact TiO2@SnO2@C heterostructured particles as anode materials for sodium-ion batteries with improved volumetric capacity

Sodium-ion batteries (SIBs) are promising candidates for large-scale energy storage. Increasing the energy density of SIBs demands anode materials with high gravimetric and volumetric capacity. To overcome the drawback of low density of conventional nanosized or porous electrode materials, compact heterostruc-tured particles are developed in this work with improved Na storage capacity by volume, which are composed of SnO2 nanoparticles loaded into nanoporous TiO2 followed by carbon coating. The resulted TiO2@SnO2@C (denoted as TSC) particles inherit the structural integrity of TiO2 and extra capacity contribution from SnO2, delivering a volumetric capacity of 393 mAh cm(-3) notably higher than that of porous TiO2 and commercial hard carbon. The heterogeneous inter-face between TiO2 and SnO2 is believed to promote the charge transfer and facilitate the redox reactions in the compact heterogeneous particles. This work demonstrates a useful strategy for electrode materials with high volumetric capacity.

Automated summary

This study developed compact heterostructured particles with improved Na storage capacity by loading SnO2 nanoparticles into nanoporous TiO2 followed by carbon coating, aiming to increase the energy density of SIBs. The resulting TiO2@SnO2@C particles inherit the structural integrity of TiO2 and have extra capacity contribution from SnO2, delivering a volumetric capacity of 393 mAh cm(-3) notably higher than that of porous TiO2 and commercial hard carbon. The heterogeneous interface between TiO2 and SnO2 promotes charge transfer and facilitates redox reactions in the compact heterogeneous particles. This work demonstrates a useful strategy for electrode materials with high volumetric capacity.