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Film strains enhance the reversible cycling of intercalation electrodes.
- Source :
-
Journal of the Mechanics & Physics of Solids . Oct2021, Vol. 155, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- A key cause of chemo-mechanical degradation in battery electrodes is that they undergo abrupt phase transformation during the charging/discharging cycle. This phase transformation is accompanied by lattice misfit strains that nucleate microcracks, induce fracture and, in extreme cases, amorphize the intercalation electrode. In this work, we propose a strategy to prevent the chemo-mechanical degradation of intercalation electrodes: we show that by engineering suitable film strains we can regulate the phase transformations in thin-film intercalation electrodes and circumvent the large volume changes. We test this strategy using a combination of theory and experiment: we first analytically derive the effect of film strain on the electrochemical response of a thin-film intercalation electrode and next apply our analytical model to a representative example (Li x V 2 O 5 with multiple phase transformations). We then test our theoretical predictions experimentally. Specifically, we electrochemically cycle thin-film V 2 O 5 electrodes with different film strains and measure their structure, voltage, and stress responses. Our findings show that tensile film strains lower the voltage for phase transformations in thin-film V 2 O 5 electrodes and facilitate their reversible cycling across a wider voltage window without chemo-mechanical degradation. These results suggest that film strain engineering is an alternative approach to preventing chemo-mechanical degradation in intercalation electrodes. Beyond thin-film electrodes, our findings from this study are applicable to the study of stress-induced phase transformations in particle-based electrodes and the thin surface layers forming on cathode particles. • Film strains modify the free energy landscape of phase transformation electrodes. • We engineer film strains to circumvent structural degradation in V 2 O 5 electrodes. • Our work initiates an approach to address chemo-mechanical challenges in electrodes. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ELECTRODES
*PHASE transitions
*CATHODES
*MICROCRACKS
Subjects
Details
- Language :
- English
- ISSN :
- 00225096
- Volume :
- 155
- Database :
- Academic Search Index
- Journal :
- Journal of the Mechanics & Physics of Solids
- Publication Type :
- Periodical
- Accession number :
- 151719192
- Full Text :
- https://doi.org/10.1016/j.jmps.2021.104551