Nitrate Additives Coordinated with Crown Ether Stabilize Lithium Metal Anodes in Carbonate Electrolyte. (28th April 2021)

• Record Type: Journal Article
• Authors: Gu, Sichen; Zhang, Si‐Wei; Han, Junwei; Deng, Yaqian; Luo, Chong; Zhou, Guangmin; He, Yanbing; Wei, Guodan; Kang, Feiyu; Lv, Wei; Yang, Quan‐Hong
• Is Part Of: Advanced functional materials. Volume 31:Number 28(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-04-28
• Subjects: carbonate electrolytes -- crown ether -- high voltage cathodes -- lithium metal batteries -- nitrate additives; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202102128
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Lithium metal anodes (LMAs) are promising for next‐generation batteries but have poor compatibility with the widely used carbonate‐based electrolytes, which is a major reason for their severe dendrite growth and low Coulombic efficiency (CE). A nitrate additive to the electrolyte is an effective solution, but its low solubility in carbonates is a problem that can be solved using a crown ether, as reported. A rubidium nitrate additive coordinated with 18‐crown‐6 crown ether stabilizes the LMA in a carbonate electrolyte. The coordination promotes the dissolution of NO3 − ions and helps form a dense solid electrolyte interface that is Li3 N‐rich which guides uniform Li deposition. In addition, the Rb (18‐crown‐6) + complexes are adsorbed on the dendrite tips, shielding them from Li deposition on the dendrite tips. A high CE of 97.1% is achieved with a capacity of 1 mAh cm −2 in a half cell, much higher than when using the additive‐free electrolyte (92.2%). Such an additive is very compatible with a nickel‐rich ternary cathode at a high voltage, and the assembled full battery with a cathode material loading up to 10 mg cm −2 shows an average CE of 99.8% over 200 cycles, indicating a potential for practical use. Abstract : A rubidium nitrate (RbNO3 ) additive coordinated with 18‐crown‐6 crown ether is proposed to stabilize the lithium metal anode in the carbonate electrolyte. A coordination reaction between them promotes the dissolution of NO3 − ions to form a dense and Li3 N‐rich solid electrolyte interface and generates the Rb(18‐crown‐6) + complexes as stable shielding ions to suppress dendrite growth.