Ultrahigh‐Rate and Ultralong‐Duration Sodium Storage Enabled by Sodiation‐Driven Reconfiguration

• Published in: Advanced energy materials 2023-04, Vol.13 (16), p.n/a
• Main Authors: Dong, Yulian, Xu, Changfan, Li, Yueliang, Zhang, Chenglin, Zhao, Huaping, Kaiser, Ute, Lei, Yong
• Format: Article
• Language: English
• Subjects: 3D micro‐nano hierarchical; Anodes; DFT calculations; Electrode materials; Ion diffusion; Reconfiguration; sodiation‐driven reconfiguration; Sodium-ion batteries; Structural integrity; vanadium sulfide
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202204324

Despite their variable valence and favorable sodiation/desodiation potential, vanadium sulfides (VSx) used as anode materials of sodium‐ion batteries (SIBs) have been held back by their capacity decline and low cycling capability, associated with the structure distortion volume expansion and pulverization. This study reports an accessible process to tackle these challenges via fabricating a 3D‐VSx anode for SIBs with ultrahigh‐rate and ultralong‐duration stable sodium storage. The sodiation‐driven reactivation of micro‐nano 3D‐VSx activates the reconfiguration effect, effectively maintaining structural integrity. Interestingly, the mechanical degradation of 3D‐VSx over the sodiation process can be controlled by fine‐tuning the operating voltage. The self‐reconfigured open nanostructures with large void space not only effectively withstand repetitive volume changes and mitigate the damaging mechanical stresses, but also in turn construct a self‐optimized shortened ion diffusion pathway. Moreover, the sodiation‐driven reconfiguration excites many active sites and optimizes a stable solid‐electrolyte interface, thereby delivering a reversible capacity of 961.4 mA h g−1 after 1500 cycles at a high rate of 2 A g−1. This work provides new insight into the rational design of electrodes toward long‐lived SIBs through sodiation‐driven reconfiguration. The reported micro‐nano 3D‐vanadium sulfides (VSx) can alleviate the issues of mechanical stress/strain and pulverization during electrochemical cycling, and ensure sufficient contact between the active material and the electrolyte. In addition, the mechanism of sodiation‐driven reconfiguration of 3D‐VSx is revealed via study of surface phenomena and structure evolution, which explains the superior electrochemical performance of 3D‐VSx.