Researchers at South Korea’s Daegu Gyeongbuk Institute of Science and Technology (DGIST) have used an electrochemical pre-passivation method to enhance the long-term cycling stability of lithium metal anodes for Li-metal batteries. A paper on their work is published in the journal Energy Storage Materials.
Seo et al.
Ultrathin, large-area Li metal anodes (LMAs) are essential for high-energy Li-metal batteries (LMBs). However, most commercially manufactured LMAs (M-Li) form a native passivation layer (NPL) during manufacturing. Intrinsically non-uniform NPL can initiate sporadic Li dendrite growth and the chemical/structural deterioration of LMAs. This study presents an electrochemical pre-passivation method to build an electrolyte-derived native layer (ENL) using electrodeposited Li (ED-Li).
Using localized high-concentration electrolytes and post-calendering, ED-Li can build a Li2CO3-less, fluorinated ENL and decrease the surface roughness. Herein, ED-Li facilitates Li nucleation during earlier Li plating owing to the electrolyte-compatible ENL, and alleviates pitting during subsequent Li stripping, thereby mitigating LMA swelling.
ED-Li improves the cycling stability of Li||NMC622 cells to outperform M-Li, which is further validated using different electrolytes under practical conditions, demonstrating its potential for use as the starting LMA in post-treatment approaches, such as protective layer coating and electrolyte-driven passivation.—Seo et al.
The surface of the lithium created with the pseudo-high-concentration electrolyte contains a high level of fluorine-based substances, thus lowering the reactivity with the electrolyte and allowing it to be manufactured thinly and compactly through simple physical compression. The lithium cathode manufactured accordingly is much smoother than commercial lithium foil, has a more uniform chemical composition on the surface layer, and can be more easily manufactured in large sizes compared to conventional manufacturing processes.
This study was supported by the “Excellent Rising Business” program of the National Research Foundation of Korea and the “Nano Convergence and Innovative Product Technology Development Project” of the Ministry of Trade, Industry and Energy.
Jiyeon Seo, Wooyoung Jeong, Minhong Lim, Bokyung Choi, Sanghyeon Park, Youngseong Jo, Jong-Won Lee, Hongkyung Lee (2023) “Electrodeposition-guided pre-passivation of Li-metal anode to enable long stable cycling of practical Li-metal batteries,” Energy Storage Materials doi: 10.1016/j.ensm.2023.102827