Shanghai researchers propose Lithium nitride film as anode protection to enhance Li-sulfur battery performance
Researchers from the Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences have proposed a strategy to suppress the polysulfide shuttle effect in Lithium-sulfur batteries—which can result in severe low efficiency—using a novel anode protection. Their paper is published in the RSC journal Chemical Communications.
The team fabricated a Li3N (lithium nitride) layer on a lithium foil anode surface by allowing one face of the foil to flow N2 gas at a constant velocity for 2 h. The other side of the container was separated from atmosphere by water-free liquid. The result was a Li electrode with a Li3N protective film; the thickness of the proactive layer is around 200-300 nm.
Li3N protection layer with high Li+ conductivity is fabricated on the surface of Li anode by a simple and in-situ method at room temperature. As the anode of Li-S battery, the protected Li shows greatly enhanced cycle performance because of the positive factors, the high Li+ conductivity of Li3N, a smooth and less resistive SEI formed between Li3N and the electrolyte, Li3N protection layer effectively inhibiting corrosive reaction between the Li metal and lithium polysulfides and the retarding growth of Li dendrites.
The discharge capacity retains at 773 mAh g-1 after 500 cycles with the average coulombic efficiency of 92.3% in the electrolyte without LiNO3, while the sulfur loading of the simple sulfur cathode was 2.5-3 mg cm-2.—Ma et al.
Guoqiang Ma, Zhaoyin Wen, Meifen Wu, Chen Shen, Qingsong Wang, Jun Jin and Xiangwei Wu (2014) “Lithium anode protection guided highly-stable lithium-sulfur battery” Chem. Commun. doi: 10.1039/C4CC05535G