Measurement on isolated lithium iron phosphate particles reveals heterogeneity in material properties distribution

We present herein localized galvanostatic and potentiodynamic measurements on lithium iron phosphate (LFP) particles, using the combination of a scanning micropipette contact method (SMCM) and scanning electron microscopy (SEM). The proposed technique allows small substrate areas (∼10 μm in diameter) decorated with LFP particles to be probed within a lithium electrolyte solution in organic carbonate solvents (0.1 M LiClO4 in propylene carbonate in the present study). SEM images of the scanned area allow the correlation of each electrochemical response to the number, and volume of the probed particles. Under favorable conditions, single particles are found within the measurement areas, thus enabling the determination of single particle properties in an anaerobic environment without the additional complications arising from the presence of binders and electronically conductive fillers. The ability to analyze a material with complementary experimental techniques at the single particle level should create new opportunities for fundamental studies and for the quality control of granular materials.