Open‐Structured V2O5·nH2O Nanoflakes as Highly Reversible Cathode Material for Monovalent and Multivalent Intercalation Batteries

• Published in: Advanced energy materials 2017-07, Vol.7 (14), p.n/a
• Main Authors: Wang, Huali, Bi, Xuanxuan, Bai, Ying, Wu, Chuan, Gu, Sichen, Chen, Shi, Wu, Feng, Amine, Khalil, Lu, Jun
• Format: Article
• Language: English
• Subjects: Aluminum-ion batteries; Al‐ion batteries; Battery cycles; Cathodes; Electrochemical analysis; Electrode materials; Intercalation; Lithium-ion batteries; Li‐ion batteries; Nanostructure; Na‐ion batteries; Rechargeable batteries; Self-assembly; Stainless steels; Structural stability; V2O5·nH2O nanoflakes; Vanadium pentoxide
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201602720

The high‐capacity cathode material V2O5·nH2O has attracted considerable attention for metal ion batteries due to the multielectron redox reaction during electrochemical processes. It has an expanded layer structure, which can host large ions or multivalent ions. However, structural instability and poor electronic and ionic conductivities greatly handicap its application. Here, in cell tests, self‐assembly V2O5·nH2O nanoflakes shows excellent electrochemical performance with either monovalent or multivalent cation intercalation. They are directly grown on a 3D conductive stainless steel mesh substrate via a simple and green hydrothermal method. Well‐layered nanoflakes are obtained after heat treatment at 300 °C (V2O5·0.3H2O). Nanoflakes with ultrathin flower petals deliver a stable capacity of 250 mA h g−1 in a Li‐ion cell, 110 mA h g−1 in a Na‐ion cell, and 80 mA h g−1 in an Al‐ion cell in their respective potential ranges (2.0–4.0 V for Li and Na‐ion batteries and 0.1–2.5 V for Al‐ion battery) after 100 cycles. A binder‐free V2O5·nH2O nanoflake cathode, prepared by a simple hydrothermal method, shows decent cyclability and capacity retention for Li+, Na+, and Al3+ insertion/deinsertion. Water molecules in the oxide network lead to a good ion mobility because of the electrostatic shielding effect. The water‐deficient V2O5·0.3H2O shows fast kinetics benefiting from the large interlayer spacing and its 3D open structure.