On the correlation between volume change of anode materials in Li-ion cells and their degradation and failure

Abstract

ming at increasing the energy density of lithium ion batteries, a Si alloy/graphite blend was used as anode material, replacing traditional pure graphite anodes. For the first time an in-situ in-operando electrochemical dilatometry was used to evaluate the expansion and contraction of this novel Si-alloy anode materials during electrochemical cycling under constant temperature. The results show an increase in volume for the first cycle (80 %) with around 12 % irreversible expansion, while for graphite based anode these values are 10% and 3%, respectively. These volume variations require particular attention when producing commercial cells. As a complementary study, commercial 18650 cells with graphite anode were investigated and the mechanical effects – jelly roll deformation – after cycling were studied by X-ray computed tomography. The deformation found for graphite electrode elucidates the importance of understanding and quantifying swelling of Si electrodes for commercial cells.

Original document

The different versions of the original document can be found in:

• https://zenodo.org/record/1456626 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

• http://dx.doi.org/10.5281/zenodo.1456626,

https://zenodo.org/record/1456626 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

• https://zenodo.org/record/1456626,

http://dx.doi.org/10.5281/zenodo.1456625 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

DOIS: 10.5281/zenodo.1456625 10.5281/zenodo.1456626