Research Progress of Bismuth-Based Ceramic Materials in Anodes of Sodium-Ion Batteries

Abstract

With the growing demand for sustainable energy storage, sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries due to sodium's abundant resources and low cost. This review focuses on bismuth (Bi)-based ceramic materials—bismuth vanadate (BiVO₄), bismuth molybdate (Bi₂MoO₆), and bismuth oxide (Bi₂O₃)—as anode materials for SIBs. These materials offer high theoretical capacities (352-386 mAh/g) via reversible alloying reactions, with Bi₂MoO₆ additionally leveraging Mo⁶⁺/Mo⁴⁺ redox reactions for enhanced capacity (>420 mAh/g). Key challenges, including poor conductivity (<10⁻⁴ S/cm) and severe volume expansion (180%-220%), are addressed through composite strategies, such as carbon coating and three-dimensional conductive networks (e.g., BiVO₄/carbon composites achieving >80% capacity retention after 200 cycles). Structural design, such as layered frameworks in Bi₂MoO₆ (0.38 nm interlayer spacing) and cubic fluorite structures in Bi₂O₃, optimizes ion diffusion and mechanical stability. Despite progress, issues like interlayer peeling in Bi₂MoO₆ and high-cost carbon nanotubes in Bi₂O₃ remain. Future research should prioritize multi-scale structural engineering (e.g., yolk-shell architectures), electrolyte optimization, and low-cost synthesis (e.g., biomass-derived carbon) to unlock the commercial potential of Bi-based ceramics for large-scale energy storage and low-end power applications.