Phase-Homogeneous LiFePO4 Powders with Crystallites Protected by Ferric-Graphite-Graphene Composite

Dmitry Agafonov; Aleksandr Bobyl; Aleksandr Kamzin; Alexey Nashchekin; Evgeniy Ershenko; Arseniy Ushakov; Igor Kasatkin; Vladimir Levitskii; Mikhail Trenikhin; Evgeniy Terukov

LAPSE:2023.3804v1

Published Article

LAPSE:2023.3804v1

Phase-Homogeneous LiFePO4 Powders with Crystallites Protected by Ferric-Graphite-Graphene Composite

Dmitry Agafonov, Aleksandr Bobyl, Aleksandr Kamzin, Alexey Nashchekin, Evgeniy Ershenko, Arseniy Ushakov, Igor Kasatkin, Vladimir Levitskii, Mikhail Trenikhin, Evgeniy Terukov

February 22, 2023

Abstract
Phase-homogeneous LiFePO4 powders have been synthesized. The content of impurity crystalline phases was less than 0.1%, according to synchrotron diffractometry (SXRD) data. Anisotropic crystallite sizes L¯Vhkl were determined by XRD. A low resistance covering layer of mechanically strong ferric-graphite-graphene composite with impregnated ferric (Fe3+) particles < 10 nm in size increases the cycleability compared to industrial cathodes. In accordance with the corrosion model, the destruction of the Fe3+-containing protective layer of crystallites predominates at the first stage, and at the second stage Fe escapes into the electrolyte and to the anode. The crystallite size decreases due to amorphization that starts from the surface. The rate capability, Q(t), has been studied as a function of L¯Vhkl, of the correlation coefficients rik between crystallite sizes, of the Li diffusion coefficient, D, and of the electrical relaxation time, τel. For the test cathode with a thickness of 8 μm, the values of D = 0.12 nm2/s, τel = 8 s were obtained. To predict the dependence Q(t), it is theoretically studied in ranges closest to experimental values: D = 0.5 ÷ 0.03 nm2/s, τel = 8/1 s, average sizes along [010] L¯1 = 90/30 nm, averaged r¯ = 0/1.

Record ID

LAPSE:2023.3804v1

Keywords

anisotropic crystallite, electrochemical battery, electrode powder, Energy Storage, energy technology, lattice structure, Mössbauer spectroscopy, storage degradation, synchrotron XRD

Subject

Energy Systems

Suggested Citation

Agafonov D, Bobyl A, Kamzin A, Nashchekin A, Ershenko E, Ushakov A, Kasatkin I, Levitskii V, Trenikhin M, Terukov E. Phase-Homogeneous LiFePO4 Powders with Crystallites Protected by Ferric-Graphite-Graphene Composite. (2023). LAPSE:2023.3804v1

Author Affiliations

Agafonov D: Department of Electrochemical Production Technology, St. Petersburg State Institute of Technology, Moskovski Ave. 26, 190013 St. Petersburg, Russia
Bobyl A: Division of Solid State Physics, Ioffe Institute, Politekhnicheskaya Str. 26, 194021 St. Petersburg, Russia
Kamzin A: Division of Solid State Physics, Ioffe Institute, Politekhnicheskaya Str. 26, 194021 St. Petersburg, Russia [ORCID]
Nashchekin A: Division of Solid State Physics, Ioffe Institute, Politekhnicheskaya Str. 26, 194021 St. Petersburg, Russia [ORCID]
Ershenko E: Division of Solid State Physics, Ioffe Institute, Politekhnicheskaya Str. 26, 194021 St. Petersburg, Russia
Ushakov A: Institute of Chemistry, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia [ORCID]
Kasatkin I: Research Park, RC XRD, St. Petersburg State University, Universitetskaya nab. 7−9, 199034 St. Petersburg, Russia
Levitskii V: RnD Center TFTE, Politekhnicheskaya Str. 26, 194021 St. Petersburg, Russia [ORCID]
Trenikhin M: Department “Chemistry and Chemical Technology”, Petrochemical Institute, Omsk State Technical University, Mira Ave. 11, 644050 Omsk, Russia
Terukov E: Department of Electronics, St. Petersburg State Electrotechnical Univeristy, ul. Professora Popova 5, 197022 St. Petersburg, Russia

Journal Name

Energies

Volume

16

Issue

3

First Page

1551

Year

2023

Publication Date

2023-02-03