Abstract
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.
Original language | English |
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Article number | 1000 |
Journal | Molecules |
Volume | 25 |
Issue number | 4 |
DOIs | |
State | Published - Feb 24 2020 |
Funding
Acknowledgments: The authors thank the staff at beamline BL14W1 in the Shanghai Synchrotron Radiation Facility (SSRF) (Shanghai, China). Neutron diffraction work was carried out at the Spallation Neutron Source (SNS), which is the U.S. Department of Energy (DOE) user facility at the Oak Ridge National Laboratory, sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). Funding: This work is financially supported by National Key Research and Development Program of China (grant no. 2018YFB0905400,2016YFB0901500) and the National Natural Science Foundation of China (grant no. 21233004, 21428303, 21621091).
Keywords
- Energy density
- Multielectron reaction
- Polyanion
- Solid-state NMR