Meaning
Surface preparation techniques use mechanical forces to remove unwanted layers or contaminants from a substrate. Secondary shear stripping involves the application of a tangential force to peel away a secondary material while leaving the primary substrate intact. This process is commonly found in the recycling of spent lithium ion batteries to separate the active electrode material from the aluminum or copper current collectors.
Precise control of the shear force prevents damage to the underlying foil.
Surface Adhesion
Strength of the bond between the coating and the substrate determines the energy required for successful removal. Secondary shear stripping must overcome the van der Waals forces and any chemical binders used in the electrode formulation. Thermal or chemical pre treatments can weaken this adhesion to make the stripping process more efficient.
Measuring the peel strength before processing helps in setting the appropriate machine parameters.
Force Application
Specialized rollers or blades exert the necessary pressure to initiate the separation of the layers. Secondary shear stripping relies on a specific angle of attack to ensure that the shear stress is concentrated at the interface. High speed operation requires mechanical components to maintain alignment and consistent force.
Material Recovery
Efficiency of the separation process dictates the purity of the reclaimed materials. Secondary shear stripping allows for the collection of the active material in a concentrated form with minimal contamination from the current collector. This high purity is essential for the direct recycling of cathode materials back into new batteries.
Successful stripping reduces the environmental impact of battery disposal and secures a domestic supply of battery minerals. Advanced systems incorporate vacuum recovery to capture fine particles that may be released during the mechanical stripping action.
