Adhesion Strength of an Active Material Layer/Cu Foil Interface in Silicon-Based Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Mechanical Engineering

Background:

• Lithium-ion batteries (LIBs) are crucial energy storage devices, with sustainability (safety, durability, recyclability) as a key focus.
• LIB anode sheets consist of active materials on a copper foil current collector.
• Active material delamination from the current collector causes short circuits and degrades performance, impacting manufacturing and recycling.

Purpose of the Study:

• To develop and apply novel methods for quantifying adhesion strength and delamination behavior in LIB anode materials.
• To investigate the interfacial adhesion between pure Si-based active materials and the copper current collector.
• To provide insights into failure mechanisms for improved battery design.

Main Methods:

• Quantifiable laser shock-wave adhesion tests were designed to assess interfacial strength.
• A physics-based computational model was employed to further quantify adhesion.
• Delamination behaviors of different anode compositions were analyzed.

Main Results:

• Laser shock-wave tests effectively characterized adhesion strength and delamination.
• A computational model provided quantitative adhesion measurements.
• Carbon-silicon (C-Si) composite anodes showed increased susceptibility to delamination due to stress concentrations from particle heterogeneity.

Conclusions:

• The developed laser shock-wave methodology offers a promising approach to evaluate anode material delamination.
• This technique provides valuable tools for designing next-generation sustainable batteries.
• Understanding interfacial strength is critical for enhancing LIB performance, safety, and recyclability.