Size-Independent Fast Ion Intercalation in Two-Dimensional Titania Nanosheets for Alkali-Metal-Ion Batteries
Jinlin Yang a,+, Xu Xiao b ,+ , Wenbin Gong c ,+ , Liang Zhao d, Guohui Li a, Kun Jiang a, Renzhi Ma e, Mark H. Rummeli d, Feng Li f, Takayoshi Sasaki e, and Fengxia Geng a ,*（耿凤霞）
a College of Chemistry, Chemical Engineering and Materials Science Soochow University Suzhou 215123 (China)
b A.J. Drexel Nanomaterials Institute and Department of Materials Science and Engineering, Drexel University Philadelphia, PA 19104 (USA)
c Key Lab of Nanodevices and Applications, Suzhou Institute of NanoTech and Nano-Bionics, Chinese Academy of Sciences Suzhou 215123 (China)
d Soochow Institute for Energy and Materials Innovations, College of Energy, Soochow University Suzhou 215006 (China)
e International Center for Materials Nanoarchitectonics, National Institute for Materials Science Tsukuba, Ibaraki 305-0044 (Japan)
f Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences Shenyang 110016 (China)
+These authors contributed equally to this work.
Angew. Chem. Int. Ed. 2019, 58, 8740--8745
Compared to lithium ions, the fast redox intercalation of large‐radius sodium or potassium ions into a solid lattice in non‐aqueous electrolytes is an elusive goal. Herein, by regulating the interlayer structure of stacked titania sheets through weakened layer‐to‐layer interactions and a robustly pillared gallery space, the two‐dimensional channel between neighboring sheets was completely open to guest intercalation, allowing fast intercalation that was practically irrespective of the carrier‐ion sizes. Regardless of employing regular Li or large‐radius Na and K ions, the material manifested zero strain‐like behavior with no significant change in both host structure and interlayer space, enabling comparable capacities for all tested ions along with excellent rate behaviors and extraordinarily long lifetimes, even with 80‐μm‐thick electrodes. The result highlights the importance of interlayer structural features for unlocking the electrochemical activity of a layered material.