Details

Autor(en) / Beteiligte

• Wang, Xiwen
• Gao, Tao
• Fan, Xiulin
• Han, Fudong
• Wu, Yiqing
• Zhang, Zhian
• Li, Jie
• Wang, Chunsheng

Titel

Tailoring Surface Acidity of Metal Oxide for Better Polysulfide Entrapment in Li-S Batteries

Ist Teil von

• Advanced functional materials, 2016-10, Vol.26 (39), p.7164-7169

Ort / Verlag

United States: Blackwell Publishing Ltd

Erscheinungsjahr

2016

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• The polysulfide shuttle reaction has severely limited practical applications of Li‐S batteries. Recently, functional materials that can chemically adsorb polysulfide show significant enhancement in cycling stability and Coulombic efficiency. However, the mechanism of the chemisorption and the control factors governing the chemisorption are still not fully understood. Here, it is demonstrated for the first time that the surface acidity of the host material plays a crucial role in the chemisorption of polysulfide. By tailoring the surface acidity of TiO2 via heteroatom doping, the polysulfide‐TiO2 interaction can be fortified and thus significantly the capacity fading be reduced to 0.04% per cycle. The discovery presented here sheds light on the mechanism of this interfacial phenomenon, and opens a new avenue that can lead to a practical sulfur/host composite cathode. Lewis acid based interaction between metal oxide host and polysulfide effectively confines polysulfides within metal oxide/sulfur cathodes. It is demonstrated that the overall electrochemical performance of lithium‐sulfur batteries can be greatly improved by tuning the surface acidity of metal oxide through the heteroatom doping.