Probing Multiscale Ion Transport and Heterogeneties in High Capacity Battery Materials : From Meso to Micronscale*

Majority of electrode materials used for advanced lithium based batteries have well defined chemical composition and particle morphology. The chemistry as well as the microstructure can undergo reversible or irreversible changes under continuous electrochemical charge-discharge cycles. These could have measurable impact on the battery capacity and life. The talk will cover the recent work related to applying x-ray transmission imaging combined with near edge absorption spectroscopy (XANES) to study the evolution of chemical oxidation state of the transition metal (TM) cations accompanied by changes in the particle morphology for lithium-manganese rich NMC cathodes (LMR-NMC). 2D XANES images collected for LMR-NMC cathodes at various stages of cycling (4.8-2.5V) can be reconstructed in 3D to measure bulk changes in TM concentration as well as monitor the change in morphology. The later part of the talk will highlight the various multiscale Raman imaging methods for studying electrode-electrolyte interfaces.