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

Lithium-ion batteries (LIB) stand as ubiquitous power sources in the industrial sector, with a mounting emphasis on their sustainability considerations, where safety, durability, and recyclability are all considered. Within the intricate architecture of LIB, the anode sheet processes a stratified composition comprising an active material layer and a copper foil serving as the current collector. The delamination of the active materials from the current collector is one of the major mechanical failure exhibitions for battery short circuits and deteriorated electrochemical performance. On the contrary, the interfacial strength between the active materials and the current collector also determines the battery manufacturing quality and battery recycling success. To cope with this emerging challenge, we designed quantifiable laser shock-wave adhesion tests to characterize the adhesion strength and delamination behaviors between pure Si-based active materials and the current collector. A physics-based computational model is also established to quantify the adhesion strength further. We discovered that the C-Si sheet is easier for delamination as layer buckling due to the more severe stress concentration around the particles due to the heterogeneity of the carbon and silicon particles. Results highlight the promise to evaluate the delamination behaviors of the current materials via an innovative methodology and provide powerful tools for next-generation sustainable battery design.