Mechanism of the First Lithiation/Delithiation Process in the Anode Material CoFeOPO₄ @C for Li-Ion Batteries

Journal Article · Fri Mar 09 00:00:00 EST 2018 · Journal of Physical Chemistry. C

DOI:https://doi.org/10.1021/acs.jpcc.8b01834· OSTI ID:1467400

Aziam, H. ^[1]; Tamraoui, Y. ^[2]; Ma, L. ^[3]; Amine, R. ^[4]; Wu, T. ^[3]; Manoun, B. ^[5]; Xu, G. L. ^[6]; Amine, K.  ^[7]; Alami, J. ^[2]; Saadoune, I.  ^[8]

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1. Materials Science and Nanoengineering, Mohammed VI Polytechnic University, Lot 660 Hay Moulay Rachid, Ben Guerir, Morocco; LCME, Faculty of Science and Technology - Cadi Ayyad University, Av. A. El Khattabi, P.B. 549 Marrakesh, Morocco; X-ray Science Division, Advanced Photon Sources, Argonne National Laboratory, Argonne, Illinois 60439, United States
2. Materials Science and Nanoengineering, Mohammed VI Polytechnic University, Lot 660 Hay Moulay Rachid, Ben Guerir, Morocco
3. X-ray Science Division, Advanced Photon Sources, Argonne National Laboratory, Argonne, Illinois 60439, United States
4. Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States; Chemical Engineering Department, University of Illinois at Chicago, Chicago, Illinois 60607, United States
5. Materials Science and Nanoengineering, Mohammed VI Polytechnic University, Lot 660 Hay Moulay Rachid, Ben Guerir, Morocco; Université Hassan 1er, Laboratoire des Sciences des Matériaux, Des Milieux et de la Modélisation (LS3M), 25000 Khouribga, Morocco
6. Chemical Science &, Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
7. Chemical Science &, Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States; Materials Science and Engineering, Stanford University, Stanford, California 94305, United States; RMC, Imam Abdulrahman Bin Faisal University (IAU), Dammam, Saudi Arabia
8. Materials Science and Nanoengineering, Mohammed VI Polytechnic University, Lot 660 Hay Moulay Rachid, Ben Guerir, Morocco; LCME, Faculty of Science and Technology - Cadi Ayyad University, Av. A. El Khattabi, P.B. 549 Marrakesh, Morocco

A cobalt iron oxyphosphate CoFeOPO₄@C (abbreviated as CFP@C) anode was prepared via a solid-state route, and its electrochemical performance was investigated vs Li+/Li over a wide voltage range of 0.01-3.0 V at different current rates C/n (n = 20, 10, 5, 2, and 1). This anode material is able to intercalate more than six lithium ions into the structure at the C/10 current rate, delivering a specific capacity of 748.23 mAh g(-1), which is much higher than the theoretical capacity (593.7 mAh g(-1)) calculated when the insertion of a five lithium ions is considered. A reversible capacity of 200 mAhg(-1) was maintained after 30 cycles. Raman spectroscopy confirmed the incorporation of carbon layers into the CoFeOPO₄@C composite. Scanning electronic microscopy revealed that CFP@C particles have an angular-flake shape with particle sizes ranging between 1 and 5 mu m. In situ X-ray absorption spectroscopy of Fe and Co at the K-edge showed that both transition metals are active during the whole discharge and charge. In operando high-energy X-ray diffraction revealed that this material undergoes a gradual evolution of the structure with lower crystallinity after the first discharge. Correlating electrochemical performance to the structural and electronic features indicated that the cycling mechanism of the CFP@C anode material exhibits a combination of intercalation and conversion processes.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: Office Cherifien des Phosphates Group (OCP)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1467400
• Journal Information: Journal of Physical Chemistry. C, Vol. 122, Issue 13; ISSN 1932-7447
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English