Orthorhombic Nb2O5-x for Durable High-Rate Anode of Li-Ion Batteries
Zichao Liu,
Wujie Dong,
Jianbo Wang,
Chenlong Dong,
Yue Lin,
I-Wei Chen,
Fuqiang Huang
Affiliations
Zichao Liu
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
Wujie Dong
State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China
Jianbo Wang
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
Chenlong Dong
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
Yue Lin
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
I-Wei Chen
Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Corresponding author
Fuqiang Huang
State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China; State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China; Corresponding author
Summary: Li4Ti5O12 anode can operate at extraordinarily high rates and for a very long time, but it suffers from a relatively low capacity. This has motivated much research on Nb2O5 as an alternative. In this work, we present a scalable chemical processing strategy that maintains the size and morphology of nano-crystal precursor but systematically reconstitutes the unit cell composition, to build defect-rich porous orthorhombic Nb2O5-x with a high-rate capacity many times those of commercial anodes. The procedure includes etching, proton ion exchange, calcination, and reduction, and the resulting Nb2O5-x has a capacity of 253 mA h g−1 at 0.5C, 187 mA h g−1 at 25C, and 130 mA h g−1 at 100C, with 93.3% of the 25C capacity remaining after cycling for 4,000 times. These values are much higher than those reported for Nb2O5 and Li4Ti5O12, thanks to more available surface/sub-surface reaction sites and significantly improved fast ion and electron conductivity. : Energy Storage; Chemical Synthesis; Energy Materials Subject Areas: Energy Storage, Chemical Synthesis, Energy Materials
