Designing bi-layer electrode-electrolyte interfaces with an asymmetric ether to enable wide-temperature lithium metal...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) are promising for next-generation energy storage but struggle with performance across wide temperature ranges.
• Sulfurized polyacrylonitrile (SPAN) cathodes offer advantages, yet their compatibility with ether electrolytes is challenging.

Purpose of the Study:

• To develop a temperature-resistant electrolyte for Li||SPAN batteries.
• To enable stable and wide-temperature operation of LMBs.
• To improve interfacial stability on both Li and SPAN electrodes.

Main Methods:

• Designed an anion-rich solvation structure using an asymmetric ether solvent (ethyl butyl ether).
• Investigated the electrolyte's effect on interphase formation on Li and SPAN electrodes.
• Tested the electrochemical performance of Li||SPAN batteries across a temperature range of -40 to 60 °C.

Main Results:

• The tailored electrolyte formed a bi-layer interphase on the Li anode, suppressing dendrite growth and inactive Li.
• A dual-layer interphase formed on the SPAN cathode, facilitating Li+ transport and preventing polysulfide shuttling.
• Achieved 72.8% capacity retention after 1000 cycles at 60 °C (1 C) and stable operation at -40 °C (0.1 C).

Conclusions:

• The developed electrolyte enables robust Li||SPAN batteries with a 100 °C operational range (-40 to 60 °C).
• Interfacial engineering with tailored electrolytes is crucial for resilient energy storage systems in extreme environments.
• The findings demonstrate practical feasibility through Ah-level pouch cell validation.