Stable Li Metal Anodes via Regulating Lithium Plating/Stripping in Vertically Aligned Microchannels

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium (Li) metal anodes are crucial for high-energy-density batteries but face safety challenges due to dendrite formation.
• Dendrites can cause short circuits and reduce battery lifespan, limiting practical applications of Li anodes.

Purpose of the Study:

• To stabilize Li metal anodes by controlling lithium plating and stripping within vertically aligned microchannels.
• To investigate the effectiveness of porous copper current collectors in mitigating Li dendrite growth.

Main Methods:

• Systematic analysis of current density distribution and Li deposit morphology on porous copper current collectors.
• Utilizing COMSOL Multiphysics simulations to understand deposition behavior based on the lightening rod theory.
• Fabricating and testing Li anodes and LiFePO4/Li full batteries.

Main Results:

• Demonstrated preferential lithium deposition on microchannel walls, effectively suppressing dendrite growth.
• Achieved enhanced cycle stability and an average Coulombic efficiency of 98.5% over 200 cycles for the Li anode.
• The LiFePO4/Li full battery exhibited excellent rate capability and stable cycling performance.

Conclusions:

• Vertically aligned microchannels on porous copper current collectors provide an effective strategy for stabilizing Li metal anodes.
• This approach significantly improves battery safety and cycle life, paving the way for practical high-energy-density rechargeable Li batteries.