Rationally designed nanostructured metal chalcogenides for advanced sodium-ion batteries

With the rapid growth of lithium-ion battery (LIB) market raising concerns about limited lithium resources and their surging prices, rechargeable sodium-ion batteries (SIBs) have attracted growing attention as an alternative to LIBs because of abundance and low cost of sodium precursors and significantly reduced fabrication costs arising from the use of Al as the anode current collector. Metal chalcogenides (MCs) have emerged as potential anodes of SIBs thanks to a large variety of available species, abundance, low cost, unique physical and chemical properties, and high theoretical capacities. However, MCs face several challenges like large volume changes during sodiation and desodiation, poor electrical conductivities, and lack of large-scale production. Hence, various strategies have been employed to address these issues for practical applications of SIBs. This review is dedicated to integrating recent progress in rational design of nanostructured MCs for SIBs. Layer- and non-layer structured MCs assembled with nanocarbon materials are discussed along with their underlying reaction mechanisms. A special focus is placed on discussion of the findings from advanced in situ/operando characterization techniques and atomistic and molecular level simulations with various examples to shed comprehensive mechanistic insights into the sodiation and desodiation processes. Finally, the challenges, potential solutions, and future perspectives for exploring new SIB electrode materials are highlighted.