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In Operando X-ray Diffraction and Transmission X-ray Microscopy of Lithium Sulfur Batteries
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posted on 2012-04-11, 00:00 authored by Johanna Nelson, Sumohan Misra, Yuan Yang, Ariel Jackson, Yijin Liu, Hailiang Wang, Hongjie Dai, Joy C. Andrews, Yi Cui, Michael F. ToneyRechargeable lithium–sulfur (Li–S) batteries
hold
great potential for high-performance energy storage systems because
they have a high theoretical specific energy, low cost, and are eco-friendly.
However, the structural and morphological changes during electrochemical
reactions are still not well understood. In this Article, these changes
in Li–S batteries are studied in operando by X-ray diffraction
and transmission X-ray microscopy. We show recrystallization of sulfur
by the end of the charge cycle is dependent on the preparation technique
of the sulfur cathode. On the other hand, it was found that crystalline
Li2S does not form at the end of discharge for all sulfur
cathodes studied. Furthermore, during cycling the bulk of soluble
polysulfides remains trapped within the cathode matrix. Our results
differ from previous ex situ results. This highlights the importance
of in operando studies and suggests possible strategies to improve
cycle life.