Stable High-Temperature Lithium-Metal Batteries Enabled by Strong Multiple Ion-Dipole Interactions

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Conventional lithium-ion batteries are limited to 60°C due to electrolyte thermal instability.
• High-temperature operation is desirable for advanced applications, but current electrolytes fail.
• Lithium-metal batteries (LMBs) offer higher energy density but face thermal challenges.

Purpose of the Study:

• To design and develop a thermally stable electrolyte for high-temperature LMBs.
• To investigate the relationship between electrolyte solvation structure and battery performance at elevated temperatures.
• To enable stable lithium deposition and solid electrolyte interphase formation at high temperatures.

Main Methods:

• Development of a novel electrolyte utilizing stable solvation structures and multiple ion-dipole interactions.
• Analysis of the electrolyte's coordination and its effect on lithium deposition behavior.
• Testing of high mass loading LiFePO4-Li cells with the new electrolyte at elevated temperatures (60°C, 90°C, 100°C).

Main Results:

• The novel electrolyte demonstrates enhanced thermal stability, enabling operation beyond 60°C.
• Cells with the new electrolyte cycled over 120 cycles at 90°C and 50 cycles at 100°C.
• Stable lithium deposition and solid electrolyte interphase formation were observed at high temperatures, improving Li Coulombic efficiency.

Conclusions:

• The designed electrolyte provides a pathway for developing high-temperature LMBs.
• Stable solvation structures are crucial for controlling Li deposition and SEI evolution at elevated temperatures.
• This research offers new insights into electrolyte design for extreme temperature battery applications.