Amorphous Redox-Rich Polysulfides for Mg Cathodes.
JACS Au
; 1(8): 1266-1274, 2021 Aug 23.
Article
in En
| MEDLINE
| ID: mdl-34467364
ABSTRACT
The lack of appropriate cathodes is restraining the advances of Mg batteries. Crystalline cathode materials suffer from sluggish reaction kinetics and low-capacity delivery. The finite type of crystalline structure further confines the rational design of cathode materials. Herein, we proposed amorphization and anion enrichment as a brand-new strategy to not only enhance the solid-state ion diffusion and provide more ion-storage sites in amorphous structure but also contribute to the local transfer of multiple electrons through the additional anionic redox centers. Accordingly, a series of amorphous titanium polysulfides (a-TiS x , x = 2, 3, and 4) were designed, which significantly outperformed their crystalline counterparts and achieved a highly competitive energy density of â¼260 Wh/kg. The unique Mg2+ storage mechanism involves the dissociation/formation of S-S bonds and changes in the coordination number of Ti, namely, a mixture of conversion and intercalation reaction, accompanied by the joint cationic (Ti) and anionic (S) redox-rich chemistry. Our proposed amorphous and redox-rich design philosophy might provide an innovative direction for developing high-performance cathode materials for multivalent-ion batteries.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
JACS Au
Year:
2021
Type:
Article
Affiliation country:
China