Reduced polysulfide shuttle in lithium–sulfur batteries using Nafion-based separators

Reference:

Bauer, I., Thieme, S., Brückner, J., Althues, H. and Kaskel, S., 2014. Reduced polysulfide shuttle in lithium–sulfur batteries using Nafion-based separators. Journal of Power Sources, 251, pp.417-422.

PI-KEM Product referenced:

Battery Materials

Abstract:

Nafion-coated polypropylene separator (Celgard 2500) is used as cation-selective membrane for lithium sulfur batteries to suppress polysulfide diffusion enhancing the charge efficiency of the cells especially at low charge/discharge rates. The charge efficiency of the 10th cycle rises from about 70% to nearly 90% at a rate of C/20. The reduction of polysulfide penetration through the Nafion-coated Celgard 2500 is also proven by visual characterization. FTIR and SEM investigations verify a smooth and dense Nafion-coating on the porous polypropylene backbone of the separator. The influence of Nafion-loading on rate capability and discharge voltage is investigated by galvanostatic charge–discharge measurements. With the lowest Nafion-loading of 0.25 mg cm−2 we are able to achieve a rate capability comparable to uncoated Celgard 2500 up to current densities of 3 mA cm−2, whereas the functionality as polysulfide shuttle inhibitor is largely preserved.

Authors:

I. Bauer, S. Thieme, J. Brückner, H. Althues, S. Kaskel

Organisation / Department Address:

Fraunhofer Institute for Material and Beam Technology (IWS), Winterbergstraße 28, D-01277 Dresden, Germany