Understanding and Preventing Dendrite Growth in Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes are crucial for high-energy-density batteries but suffer from dendrite growth, limiting their practical application.
• Existing strategies to mitigate dendrite formation, such as interface layers and surface modifications, have limitations.
• The fundamental mechanisms and influencing factors of lithium dendrite growth remain incompletely understood.

Purpose of the Study:

• To investigate the underlying causes of lithium dendrite formation in lithium metal anodes.
• To propose and demonstrate a novel three-dimensional (3D) composite lithium anode design to overcome dendrite issues.
• To evaluate the electrochemical performance of the developed 3D lithium anode compared to traditional lithium foils.

Main Methods:

• A 3D composite lithium anode was fabricated using renewable carbonized wood doped with tin.
• Electrochemical performance was assessed through galvanostatic cycling at various current densities (0.1–10 mA cm⁻²).
• Long-term cycling stability was tested at 1 mA cm⁻² for 1000 hours and 2 mA cm⁻² for 500 hours.
• Density functional theory (DFT) calculations were employed to identify suitable alloying elements for 3D lithium anodes.

Main Results:

• The 3D composite lithium anode exhibited significantly lower overpotential compared to lithium foils.
• Stable cycling was achieved at high current densities without observable dendrite growth.
• The 3D structure increased surface area and created nanoscale separation walls, facilitating uniform lithium plating.
• Tin alloying provided abundant nucleation centers, preventing non-uniform lithium deposition.

Conclusions:

• Three-dimensional metal anodes represent a promising strategy for suppressing lithium dendrite growth.
• The developed 3D composite lithium anode demonstrates superior electrochemical stability and performance.
• The combination of 3D architecture and appropriate alloying elements is key to enabling safe and efficient lithium metal anodes.