Heterostructure Engineering in Electrode Materials for Sodium-Ion Batteries: Recent Progress and Perspectives: Recent progress and perspectives

Sodium-ion batteries (SIBs) have stepped into the spotlight as a promising alternative to lithium-ion batteries for large-scale energy storage systems. However, SIB electrode materials, in general, have inferior performance than their lithium counterparts because Na ⁺ is larger and heavier than Li ⁺ . Heterostructure engineering is a promising strategy to overcome this intrinsic limitation and achieve practical SIBs. We provide a brief review of recent progress in heterostructure engineering of electrode materials and research on how the phase interface influences Na ⁺ storage and transport properties. Efficient strategies for the design and fabrication of heterostructures ( in situ methods) are discussed, with a focus on the heterostructure formation mechanism. The heterostructure's influence on Na ⁺ storage and transport properties arises primarily from local distortions of the structure and chemomechanical coupling at the phase interface, which may accelerate ion/electron diffusion, create additional active sites, and bolster structural stability. Finally, we offer our perspectives on the existing challenges, knowledge gaps, and opportunities for the advancement of heterostructure engineering as a means to develop practical, high-performance sodium-ion batteries.