XRD/Neutron Diffraction
Diffraction is a key technique we use to gain insight into the atomic-scale arrangements of atoms that dictate the functional properties of the materials we study. We have access to excellent x-ray (Cu, Co, Ag) and neutron (link to PEARL) sources in-house, as well as active collaborations with large-scale facilities (e.g. ESRF synchrotron and ISIS neutron source). We can perform experiments operando, that is directly on working battery cells, to determine the structural evolution of the electrode materials as a function of the cycling parameters. See, for example, Zhaolong and Swapna’s work on elucidating the inner workings of lithium-oxygen electrodes published in Chemistry of Materials 1–5.
In particular, our group specializes in microbeam diffraction that utilizes a hard x‑ray beam focused into a micron‑sized spot to yield data in between classical powder and single‑crystal patterns. Microbeam diffraction allows us to directly follow the evolution of multiple individual crystallites in an electrode and uncover inhomogeinities in the μm and nm scales that typically control performances. See, for example Martijn’s latest paper on LFP and NMC electrodes published in Frontiers in Energy Research 6,7.
References
(1) Li, Z.; Ganapathy, S.; Xu, Y.; Zhu, Q.; Chen, W.; Kochetkov, I.; George, C.; Nazar, L. F.; Wagemaker, M. Fe2O3 Nanoparticle Seed Catalysts Enhance Cyclability on Deep (Dis)Charge in Aprotic LiO2 Batteries. Adv. Energy Mater. 2018, 8 (18). doi.org/10.1002/aenm.201703513.
(2) Li, Z.; Ganapathy, S.; Xu, Y.; Heringa, J. R.; Zhu, Q.; Chen, W.; Wagemaker, M. Understanding the Electrochemical Formation and Decomposition of Li 2 O 2 and LiOH with Operando X-Ray Diffraction. Chem. Mater. 2017, 29 (4), 1577–1586. doi.org/10.1021/acs.chemmater.6b04370.
(3) Ganapathy, S.; Li, Z.; Anastasaki, M. S.; Basak, S.; Miao, X. F.; Goubitz, K.; Zandbergen, H. W.; Mulder, F. M.; Wagemaker, M. Use of Nano Seed Crystals to Control Peroxide Morphology in a Nonaqueous Li-O2 Battery. J. Phys. Chem. C 2016, 120 (33), 18421–18427. doi.org/10.1021/acs.jpcc.6b04732.
(4) Ganapathy, S.; Heringa, J. R.; Anastasaki, M. S.; Adams, B. D.; Van Hulzen, M.; Basak, S.; Li, Z.; Wright, J. P.; Nazar, L. F.; Van Dijk, N. H.; Wagemaker, M. Operando Nanobeam Diffraction to Follow the Decomposition of Individual Li2O2 Grains in a Nonaqueous Li-O2 Battery. J. Phys. Chem. Lett. 2016, 7 (17), 3388–3394. doi.org/10.1021/acs.jpclett.6b01368.
(5) Ganapathy, S.; Adams, B. D.; Stenou, G.; Anastasaki, M. S.; Goubitz, K.; Miao, X.; Nazar, L. F.; Wagemaker, M. Nature of Li 2 O 2 Oxidation in a Li − O 2 Battery Revealed by Operando. J. Am. Chem. Soc. 2014, 136, 16335–16344.
(6) van Hulzen, M.; Ooms, F. G. B.; Wright, J. P.; Wagemaker, M. Revealing Operando Transformation Dynamics in Individual Li-Ion Electrode Crystallites Using X-Ray Microbeam Diffraction. Front. Energy Res. 2018, 6 (July). doi.org/10.3389/fenrg.2018.00059.
(7) Zhang, X.; Van Hulzen, M.; Singh, D. P.; Brownrigg, A.; Wright, J. P.; Van Dijk, N. H.; Wagemaker, M. Direct View on the Phase Evolution in Individual LiFePO 4 Nanoparticles during Li-Ion Battery Cycling. Nat. Commun. 2015, 6 (May), 1–7. doi.org/10.1038/ncomms9333.