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March 2013

Size Doesn't Matter: Mechanical Deformation Remains in Small Crystals


Scientific Achievement

Homogenous, 10nm Sn nanocrystals were prepared as a model platform to study the impact of crystal size on mechanical deformation during electrochemical cycling with lithium. Using ex-situ TEM, significant damage was observed after the first lithiation, explaining the capacity decay observed after 50 cycles. Size reduction at these scales is insufficient to prevent mechanical damage caused by electrochemical cycling.

Significance

Alloy-based materials are being considered as electrodes in high energy density Li ion batteries, but their performance is compromised by large volume changes during cycling. Despite expectation that downsizing crystals would avoid mechanical damage, this work suggests that some particle damage may be inevitable. Thus, future research might be better directed toward compensatory mechanisms for this process.  

Research Details


L. Xu, C. Kim, A. K. Shukla, A. Dong, T. M. Mattox, D. J. Milliron, J. Cabana. Nano Letters, 2013, (In Press) DOI: 10.1021/nl400418c