TY - JOUR

T1 - Phase-Homogeneous LiFePO4 Powders with Crystallites Protected by Ferric-Graphite-Graphene Composite

AU - Агафонов, Дмитрий

AU - Бобыль, Александр

AU - Александр, Камзин

AU - Нащекин, А.В.

AU - Ершенко, Евгений

AU - Ушаков, Арсений

AU - Касаткин, Игорь Алексеевич

AU - Левитский, Владимир

AU - Тренихин, Михаил

AU - Теруков, Евгений

PY - 2023/2/3

Y1 - 2023/2/3

N2 - 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 (Formula presented.) 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 (Formula presented.), of the correlation coefficients (Formula presented.) 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] (Formula presented.) = 90/30 nm, averaged (Formula presented.) = 0/1.

AB - 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 (Formula presented.) 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 (Formula presented.), of the correlation coefficients (Formula presented.) 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] (Formula presented.) = 90/30 nm, averaged (Formula presented.) = 0/1.

KW - Mössbauer spectroscopy

KW - anisotropic crystallite

KW - electrochemical battery

KW - electrode powder

KW - energy storage

KW - energy technology

KW - lattice structure

KW - storage degradation

KW - synchrotron XRD

UR - https://www.mendeley.com/catalogue/a0970e63-2c13-31da-b88a-983e928d6c6a/

U2 - 10.3390/en16031551

DO - 10.3390/en16031551

M3 - Article

VL - 16

JO - Energies

JF - Energies

SN - 1996-1073

IS - 3

M1 - 1551

ER -