Meaning
An internal mechanical force vector acting parallel to the interface between active material coatings and metallic current collectors induces interfacial sliding during battery expansion and contraction cycles. Evaluation of electrode shear stress quantifies the mechanical stability of porous coatings subjected to cyclic volume changes during lithium insertion. Physical boundaries apply to active material coating interfaces, stopping at external module structural frames and cell housing walls.
Coating formulators specify minimum interfacial strength thresholds to prevent active material delamination during high-power operations.
Frictional Mechanics
Interfacial friction governs micro-sliding between active particles and current collector foils during swelling cycles. Particle movement generates localized shear forces that weaken polymer binder bonds over extended cycling. Frictional losses accelerate particle isolation and capacity fade.
Coating Adhesion
Binder formulations resist shear forces through chemical cross-linking and mechanical interlocking with foil surfaces. Standard peel tests quantify binder strength before cell assembly, but in situ electrode shear stress increases significantly as lithium intercalation expands active particles. Strong interfacial adhesion maintains electrical connectivity across active material layers.
Deformation Behavior
Differential volume changes across electrode thickness gradients induce internal sliding stresses. Mechanical constraints imposed by adjacent separator layers intensify localized shear forces during fast charging. Cyclic deformation ultimately leads to micro-cracking and loss of active material surface area.
