Recognition of V3+/V4+/V5+ Multielectron Reactions in Na3V(PO4)2: A Potential High Energy Density Cathode for Sodium-Ion Batteries

Molecules

Yuxuan Xiang¹  Ziteng Liang¹  Yong Yang¹  Weimin Zhao²  Haodong Liu³  Yan Chen⁴  Ke An⁴  Rui Liu⁵ 

[1] 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;College of Chemical Engineering and Safety, Binzhou University, Binzhou 256603, China;Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA;Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA;School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;

关键词: polyanion;    energy density;    multielectron reaction;    solid-state nmr;   

DOI  :  10.3390/molecules25041000

来源: DOAJ

【 摘 要 】

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 Na_2−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.

【 授权许可】

Unknown