How Stacking Pressure and Temperature Regulate Lithium Plating and Stripping in Solid-State Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Stable integration of solid-state electrolytes (SSE) with lithium metal anodes is crucial for high-energy-density solid-state lithium metal batteries (SSLMBs).
• Uncontrolled lithium filament growth and dead lithium accumulation hinder practical applications of SSLMBs.
• The roles of stacking pressure and temperature in regulating lithium deposition/stripping dynamics are poorly understood.

Purpose of the Study:

• To develop a coupled model characterizing lithium plating and stripping in SSLMBs.
• To investigate the influence of stacking pressure and operating temperature on lithium morphology and dead lithium formation.
• To clarify the impact on internal short-circuit risk and irreversible capacity loss.

Main Methods:

• Developed an electrochemical, mechanical, and phase-field coupled model.
• Analyzed the morphological evolution of lithium filaments under varying pressure and temperature.
• Constructed phase diagrams correlating pressure, temperature, filament height, and capacity loss rate.

Main Results:

• Revealed mechanisms of stacking pressure and temperature on lithium filament morphology and dead lithium distribution.
• Quantified the effect of these parameters on internal short-circuit risk and irreversible capacity loss.
• Demonstrated a strong dependency between lithium deposition morphology and dead lithium formation, impacting cycling performance.

Conclusions:

• Stacking pressure and temperature significantly regulate internal short-circuit risk and cyclic capacity loss in SSLMBs.
• Favorable lithium deposition morphology is critical for enhancing cycling stability.
• Provides theoretical guidance for optimizing external physical field regulation strategies for safer and more stable SSLMBs.