Decoupling Kinetic and Shuttle Limitations in Li─S Batteries Enabled by Temperature Responsive Functional Interlayer

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur batteries (LSBs) are promising for high energy density but face challenges.
• Sluggish lithium sulfide (Li2S) nucleation and polysulfide shuttling impede performance.
• These issues are significantly influenced by operating temperature.

Purpose of the Study:

• To investigate the temperature-dependent functionality of an electrocatalytic MXene interlayer in LSBs.
• To decouple the limitations of Li2S nucleation and polysulfide shuttling.
• To develop a strategy for thermally stable LSB operation.

Main Methods:

• Potentiostatic nucleation studies to analyze Li2S formation kinetics.
• Post-cycling Field Emission Scanning Electron Microscopy (FESEM) for morphological analysis.
• Ex situ X-ray Photoelectron Spectroscopy (XPS) to determine chemical states and interactions.

Main Results:

• MXene interlayer accelerates Li2S nucleation at low temperatures.
• MXene effectively anchors polysulfides at high temperatures, mitigating shuttle effects.
• Stable cycling and improved sulfur utilization were achieved across a wide temperature range (-10°C to 55°C).
• Dendrite formation was suppressed.

Conclusions:

• The MXene interlayer exhibits adaptive, temperature-responsive behavior.
• This strategy effectively addresses both kinetic and shuttle limitations in LSBs.
• The findings offer a new approach for designing high-performance LSBs for diverse thermal conditions.