Revealing lithium-silicide phase transformations in nano-structured silicon based lithium ion batteries via in-situ NMR spectroscopy
Nature Publishing Group
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Ogata, K., Salager, E., Kerr, C., Fraser, A., Ducati, C., Morris, A., Hofmann, S., & et al. (2014). Revealing lithium-silicide phase transformations in nano-structured silicon based lithium ion batteries via in-situ NMR spectroscopy. Nature Communications, 5 https://doi.org/10.1038/ncomms4217
Nano-structured silicon anodes are attractive alternatives to graphitic carbons in rechargeable Li-ion batteries, owing to their extremely high capacities. Despite their advantages, numerous issues remain to be addressed, the most basic being to understand the complex kinetics and thermodynamics that control the reactions and structural rearrangements. Elucidating this necessitates real-time in-situ metrologies, which are highly challenging, if the whole electrode structure is studied at an atomistic level for multiple cycles under realistic cycling conditions. Here we report that Si nanowires grown on a conducting carbon-fibre support provide a robust model battery system that can be studied by 7Li in-situ NMR spectroscopy. The method allows the (de)alloying reactions of the amorphous silicides to be followed in the 2nd cycle and beyond. In combination with density-functional theory calculations, the results provide insight into the amorphous and amorphous-to-crystalline lithium-silicide transformations, particularly those at low voltages, which are highly relevant to practical cycling strategies.
K.O acknowledges a research fellowship from Japanese Society for the Promotion of Science (JSPS). E.S acknowledges support by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme and thanks Churchill College (Cambridge, UK) for a non-stipendiary Raymond and Beverly Sackler Research fellowship. C.J.K and A.E.F acknowledge a research studentship from the Cambridge Nano Science and Technology Doctoral Training Centre (NanoDTC). A.J.M acknowledges the support from the Winton Programme for the Physics of Sustainability. S.H acknowledges funding from ERC grant InsituNANO (project number 279342). C.P.G and C.D thank the Royal Society, and C.P.G thanks European Research Council (ERC). C.P.G. acknowledges support from the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy, under Contract DE-AC02-05CH11231, subcontract 6952000.
European Research Council (279342)
European Research Council (259619)
External DOI: https://doi.org/10.1038/ncomms4217
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246438