Nitrate Additives Coordinated with Crown Ether Stabilize Lithium Metal Anodes in Carbonate Electrolyte

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 Li3N‐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.

Crowning Lithium Ions in Hole‐Transport Layer toward Stable Perovskite Solar Cells

“…An extra intense peak with a m/e of 183.1 can be assigned to Li(12-crown-4) + in the target precursor, confirming the specific coordinating reaction. [27] The interaction between 12-crown-4 and Li + ion was further characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy. Compared with the mixed solution without LiTFSI (acetonitrile+12-crown-4), a positive 1 H NMR chemical shift of 12-crown-4 after being combined with Li + ion is discerned for the mixture with LiTFSI (Figure 1e), which suggests a strong Li-O solvation.…”

Mapping Techniques for the Design of Lithium‐Sulfur Batteries

“…For the electrolyte, LiNO 3 is the most widely used additive in Li-S battery because its excellent efficiency for the stabilization of SEI. [18][19][20] Besides, other materials have also been used as electrolyte additives to regulate the ion distribution and deposition, which suppress the formation of lithium dendrite. [21][22][23] For the artificial SEI, efforts are focused on the enhanced chemical stability and mechanical robustness, which ensure the integrity of SEI during repeated cycling.…”

Insights on “nitrate salt” in lithium anode for stabilized solid electrolyte interphase

“…Also, inorganic‐rich SEI has an improved mechanical strength, which can suppress Li dendrite growth 16 . Nitrates are representative inorganic electrolyte additives 17–19 . The NO 3 – can react with metallic Li to form inorganic Li 3 N, LiN x O y , and Li 2 O uniformly distributed in the SEI, which improves the Li plating/stripping behavior and enhances the electrochemical performance 16,20 .…”

“…16 Nitrates are representative inorganic electrolyte additives. [17][18][19] The NO 3 can react with metallic Li to form inorganic Li 3 N, LiN x O y , and Li 2 O uniformly distributed in the SEI, which improves the Li plating/stripping behavior and enhances the electrochemical performance. 16,20 With high Li + conductivity and electronic resistivity, Li 3 N and LiN x O y can accelerate Li + migration through the SEI layer, leading to uniform and fast Li plating/stripping.…”