Wide Temperature 500 Wh kg^-1 Lithium Metal Pouch Cells.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) face performance limitations due to temperature fluctuations.
• Operating LMBs across a wide temperature range remains a significant challenge for practical applications.

Purpose of the Study:

• To develop a wide temperature adaption electrolyte for enhanced LMB performance.
• To investigate the role of the solid electrolyte interphase (SEI) in temperature-dependent LMB behavior.

Main Methods:

• Formulation and testing of a novel electrolyte for LMBs.
• Electrochemical performance evaluation of large-format pouch cells across a wide temperature spectrum (-40°C to 60°C).
• Analysis of SEI composition and its influence on ion transport and dendrite formation.

Main Results:

• The developed electrolyte enables LMBs to operate from -40°C to 60°C with excellent electrochemical performance.
• Large 5.8 Ah pouch cells achieved high energy densities (503.3 Wh kg⁻¹ at 25°C, 339 Wh kg⁻¹ at -40°C).
• A LiF-rich, anion-derived SEI was identified, facilitating Li⁺ diffusion and desolvation, thus inhibiting dendrite growth at low temperatures.

Conclusions:

• The SEI chemistry is critical for achieving wide-temperature operation in lithium metal batteries.
• Optimized SEI properties enhance lithium-ion kinetics and suppress dendrite formation, enabling stable LMB performance in extreme conditions.
• This research paves the way for robust lithium metal batteries suitable for diverse environmental conditions.