Enabling intercalation‐type TiNb24O62 anode for sodium‐ and potassium‐ion batteries via a synergetic strategy of oxygen vacancy and carbon incorporation

• Published in: SusMat (Online) 2023-04, Vol.3 (2), p.222-234
• Main Authors: Vijaya Kumar Saroja, Ajay Piriya, Wang, Zhipeng, Tinker, Henry R., Wang, Feng Ryan, Shearing, Paul R., Xu, Yang
• Format: Article
• Language: English
• Subjects: anode; Anodes; Carbon; Crystal structure; defects; Diffusion rate; Electrode materials; Electron diffusion; Energy storage; Graphene; Intercalation; Metal oxides; Oxidation; Oxygen; Potassium; potassium‐ion battery; Reaction kinetics; Sodium; sodium‐ion battery; sustainability; Titanium
• ISSN: 2692-4552; 2766-8479; 2692-4552
• DOI: 10.1002/sus2.113

The key to develop earth‐abundant energy storage technologies sodium‐ and potassium‐ion batteries (SIBs and PIBs) is to identify low‐cost electrode materials that allow fast and reversible Na+/K+ intercalation. Here, we report an intercalation‐type material TiNb24O62 as a versatile anode for SIBs and PIBs, via a synergistic strategy of oxygen vacancy and carbon incorporation to enhance ion and electron diffusion. The TiNb24O62−x/reduced graphene oxide (rGO) composite anode delivers high reversible capacities (130 mA h g−1 for SIBs and 178 mA h g−1 for PIBs), great rate performance (54 mA h g−1 for SIBs and 37 mA h g−1 for PIBs at 1 A g−1), and superior cycle stability (73.7% after 500 cycles for SIBs and 84% after 300 cycles for PIBs). The performance is among the best results of intercalation‐type metal oxide anodes for SIBs and PIBs. The better performance of TiNb24O62−x/rGO in SIBs than PIBs is due to the better reaction kinetics of the former. Moreover, mechanistic study confirms that the redox activity of Nb4+/5+ is responsible for the reversible intercalation of Na+/K+. Our results suggest that TiNb24O62−x/rGO is a promising anode for SIBs and PIBs and may stimulate further research on intercalation‐type compounds as candidate anodes for large ion batteries. This work represents a synergistic strategy of oxygen vacancy and carbon incorporation to enable the Na+/K+ intercalation in titanium niobium oxide anode and improve the intercalation reaction kinetics. The results highlight the promise of utilizing metal oxides as intercalation anodes for earth‐abundant energy storage technologies.