High Volumetric and Gravimetric Capacity Electrodeposited Mesostructured Sb₂O₃ Sodium Ion Battery Anodes

Sodium ion batteries (SIBs) are considered promising alternatives to lithium ion batteries for grid-scale and other energy storage applications because of the broad geographical distribution and low cost of sodium relative to lithium. Here, fabrication and characterization of high gravimetric and volumetric capacity 3D Ni-supported Sb₂O₃ anodes for SIBs are presented. The electrodes are prepared by colloidal templating and pulsed electrodeposition followed by heat treatment. The colloidal template is optimized to provide large pore interconnects in the 3D scaffold to enable a high active materials loading and accommodate a large volume expansion during cycling. An electrodeposited loading of 1.1 g cm⁻³ is chosen to enable a combined high gravimetric and volumetric capacity. At this loading, the electrodes exhibit a specific capacity of ≈445 mA h g⁻¹ and a volumetric capacity of ≈488 mA h cm⁻³ with a capacity retention of 89% after 200 cycles at 200 mA g⁻¹. The stable cycling performance can be attributed to the 3D metal scaffold, which supports active materials undergoing large volume changes, and an initial heat treatment appears to improve the adhesion of the Sb₂O₃ to the metal scaffold.