Thermodynamics, Kinetics and Structural Evolution of ε-LiVOPO ₄ over Multiple Lithium Intercalation

Journal Article · Mon Feb 29 00:00:00 EST 2016 · Chemistry of Materials

DOI:https://doi.org/10.1021/acs.chemmater.5b04880· OSTI ID:1387501

Lin, Yuh-Chieh ^[1]; Wen, Bohua ^[2]; Wiaderek, Kamila M. ^[3]; Sallis, Shawn ^[4]; Liu, Hao ^[3]; Lapidus, Saul H. ^[3]; Borkiewicz, Olaf J. ^[3]; Quackenbush, Nicholas F. ^[5]; Chernova, Natasha A. ^[2]; Karki, Khim ^[6]; Omenya, Fredrick ^[2]; Chupas, Peter J. ^[3]; Piper, Louis F. J. ^[7]; Whittingham, M. Stanley ^[2]; Chapman, Karena W. ^[3]; Ong, Shyue Ping ^[1]

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1. Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive # 0448, La Jolla, California 92093, United States
2. NECCES, Binghamton University, Binghamton, New York 13902, United States
3. X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
4. Materials Science &, Engineering, Binghamton University, Binghamton, New York 13902, United States
5. Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, New York 13902, United States
6. NECCES, Binghamton University, Binghamton, New York 13902, United States; Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
7. Materials Science &, Engineering, Binghamton University, Binghamton, New York 13902, United States; Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, New York 13902, United States

In this work, we demonstrate the stable cycling of more than one Li in solid-state-synthesized ε-LiVOPO4 over more than 20 cycles for the first time. Using a combination of density functional theory (DFT) calculations, X-ray pair distribution function (PDF) analysis and X-ray absorption near edge structure (XANES) measurements, we present a comprehensive analysis of the thermodynamics, kinetics, and structural evolution of ε-LixVOPO4 over the entire lithiation range. We identify two intermediate phases at x = 1.5 and 1.75 in the low-voltage regime using DFT calculations, and the computed and electrochemical voltage profiles are in excellent agreement. Operando PDF and EXAFS techniques show a reversible hysteretic change in the short (<2 Å) V—O bond lengths coupled with an irreversible extension of the long V—O bond (>2.4 Å) during low-voltage cycling. Hydrogen intercalation from electrolyte decomposition is a possible explanation for the ~2.4 Å V—O bond and its irreversible extension. Finally, we show that ε-LixVOPO4 is likely a pseudo-1D ionic diffuser with low electronic conductivity using DFT calculations, which suggests that nanosizing and carbon coating is necessary to achieve good electrochemical performance in this material.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Northeastern Center for Chemical Energy Storage (NECCES)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0001294
• OSTI ID: 1387501
• Journal Information: Chemistry of Materials, Vol. 28, Issue 6; Related Information: NECCES partners with Stony Brook University (lead); Argonne National Laboratory; Binghamton University; Brookhaven National University; University of California, San Diego; University of Cambridge, UK; Lawrence Berkeley National Laboratory; Massachusetts Institute of Technology; University of Michigan; Rutgers University; ISSN 0897-4756
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
energy storage (including batteries and capacitors)
defects
charge transport
materials and chemistry by design
synthesis (novel materials)