Recognition of V<sup>3+</sup>/V<sup>4+</sup>/V<sup>5+</sup> Multielectron Reactions in Na<sub>3</sub>V(PO<sub>4</sub>)<sub>2</sub>: A Potential High Energy Density Cathode for Sodium-Ion Batteries
Rui Liu,
Ziteng Liang,
Yuxuan Xiang,
Weimin Zhao,
Haodong Liu,
Yan Chen,
Ke An,
Yong Yang
Affiliations
Rui Liu
School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
Ziteng Liang
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Yuxuan Xiang
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Weimin Zhao
College of Chemical Engineering and Safety, Binzhou University, Binzhou 256603, China
Haodong Liu
Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
Yan Chen
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
Ke An
Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
Yong Yang
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
Na3V(PO4)2 was reported recently as a novel cathode material with high theoretical energy density for Sodium-ion batteries (SIBs). However, whether V3+/V4+/V5+ multielectron reactions can be realized during the charging process is still an open question. In this work, Na3V(PO4)2 is synthesized by using a solid-state method. Its atomic composition and crystal structure are verified by X-ray diffraction (XRD) and neutron diffraction (ND) joint refinement. The electrochemical performance of Na3V(PO4)2 is evaluated in two different voltage windows, namely 2.5−3.8 and 2.5−4.3 V. 51V solid-state NMR (ssNMR) results disclose the presence of V5+ in Na2−xV(PO4)2 when charging Na3V(PO4)2 to 4.3 V, confirming Na3V(PO4)2 is a potential high energy density cathode through realization of V3+/V4+/V5+ multielectron reactions.
