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Monitoring LixFeSO4F (x = 1, 0.5, 0) Phase Distributions in Operando To Determine Reaction Homogeneity in Porous Battery Electrodes
journal contribution
posted on 2017-08-09, 00:00 authored by Andreas Blidberg, Torbjörn Gustafsson, Carl Tengstedt, Fredrik Björefors, William R. BrantIncreasing
the energy and power density simultaneously remains
a major challenge for improving electrochemical energy storage devices
such as Li-ion batteries. Understanding the underlying processes in
operating electrodes is decisive to improve their performance. Here,
an extension of an in operando X-ray diffraction technique is presented,
wherein monitoring the degree of coexistence between crystalline phases
in multiphase systems is used to investigate reaction homogeneity
in Li-ion batteries. Thereby, a less complicated experimental setup
using commercially available laboratory equipment could be employed.
By making use of the intrinsic structural properties of tavorite type LiFeSO4F, a promising cathode material for Li-ion
batteries, new insights into its nonequilibrium behavior are gained.
Differences in the reaction mechanism upon charge and discharge are
shown; the influence of adequate electronic wiring for the cycling
stability is demonstrated, and the effect of solid state transport
on rate performance is highlighted. The methodology is an alternative
and complementary approach to the expensive and demanding techniques
commonly employed for time-resolved studies of structural changes
in operating battery electrodes. The multiphase behavior of LiFeSO4F is commonly observed for other insertion type electrode
materials, making the methodology transferable to other new energy
storage materials. By expanding the possibilities for investigating
complex processes in operating batteries to a larger community, faster
progress in both electrode development and fundamental material research
can be realized.