Scientific Achievement

Insights are obtained into the mechanisms of adding Cs+ to protect the Li-metal electrode during battery cycling.

Significance and Impact

The addition of Cs+ can significantly enhance both the formation of well aligned Li nanorods and the reversibility of the Li electrode. In situ ¹³³Cs NMR directly confirms that Cs+ migrates to the Li electrode to form a positively charged electrostatic shield during the charging process.

Research Details

• Special symmetric Li planar cells similar to commercial coin cells (except that the stainless container was replaced by a plastic holder) were fabricated for in situ ⁷Li and ¹³³Cs NMR investigations.
• The effect of the Cs additive on Li deposition onto Li-metal electrodes was investigated using quantitative in situ ⁷Li and ¹³³Cs NMR.
• In situ ⁷Li NMR showed that a decreased amount of dendrites were formed on Li electrodes during cycling for the battery with Cs additives.
• In situ¹³³Cs NMR indicated that Cs+ migrated to the Li electrode during the charging process.

DOI:10.1016/j.jpowsour.2015.10.067

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