A platform for in situ Raman and stress characterizations of V2O5 cathode using MEMS device

We present an in situ approach for the characterization of lithium intercalation/deintercalation in thinfilm Li-ion battery electrodes. The method allows simultaneous measurement of microstructural changes during lithiation using micro-Raman (mRaman) spectroscopy in parallel with stress changes via optical interferometry. We observe evolution in the microstructure and stress in the various crystal phases in the Li-V-O system, including both reversible and irreversible phase transitions. We also correlate spectral shifts in certain Raman active modes with changes in the electrode stress, and thus confirm previously hypothesized origins of these observations. Ultimately, the combined stress/mRaman in situ technique can be leveraged as a characterization platform for a wide variety of electrode materials for advancing battery performance. © 2017 Elsevier Ltd. All rights reserved.