Research Progress on Sb-based Anode Material for Sodium-ion Batteries

Sb-base anode materials are considered as a promising material for sodium ions batteries (SIBs) and have attracted close attention of researchers, due to its higher theoretical specific capacity and lower cost than carbon materials. Although Sb metal has many advantages such as good safety performance and easy to synthesis, some problems still exist during the repeated charging/discharging processes: (1)due to the larger volume expansion, sodium ions irreversible detaching freely which declines its cycling efficiency; (2)the crystal structure collapse and material pulverization can bring about the cycle stability of electrode materials diminish and the capacity greatly reduce. The electrochemical properties of Sb metal have been greatly enhanced by means of morphology and structure regulation. Even so, it is still unable to effectively solve the problem of low charging and discharging efficiency and rapid capacity decay arisen from volume expansion of Sb metal during cycling. In order to solve this problem, Sb/C composite materials and Sb-base alloy materials were designed and developed. Sb/C composite materials makes use of the advantages of carbon materials, such as good flexibility, excellent conductivity and adjustable morphology and structure, etc, so that the cycling performance of modified electrode material has been improved to some extent. The reaction mechanism of Sb-based non-metallic compound materials, such as Sb oxides and Sb sulfides, is the coexistence of alloying reaction and transformation reaction mechanism, so both can contribute capacity, making such materials have a higher specific capacity. In order to stabilize structural properties and restrain volume expansion at the same time, other composite materials of Sb with complex structure but excellent electrochemical performance can be constructed. In this paper, some common Sb-based(Sb metal, Sb/C compounds, alloy, oxides, sulfides and other composites of Sb)anode materials for SIBs are introduced. Meanwhile, different materials of their storage mechanism of sodium, performance characteristics, existing problems and optimization methods for electrochemical performance are compared and analyzed. It was worth noting that single modification method cannot greatly improve the electrochemistry properties of these materials. A more effective way is to apply various modification methods comprehensively, such as optimum structure, well control of alloy composition as well as select better reducing agents, binders and electrolyte additives, etc. Finally, challenges of Sb-based anode materials for sodium ion batteries and their future commercial application are presented. © 2020, Materials Review Magazine. All right reserved.