<p>This study focuses on the interfacial failure and mechanical response mechanisms of lithium-ion battery (LIB) electrodes during calendering. Using peel tests, morphology analysis, and discrete element method (DEM) simulation, we systematically investigated the effects of 0–200 MPa calendering stress on the interfacial adhesion between the current collector and active layer, current collector mechanical properties, and thickness effects. The results show that calendering stress significantly enhances interfacial adhesion strength but reduces current collector ductility. Thinner current collectors show more severe tensile strength attenuation, along with increased surface undulation and localized indentations. This work highlights the need for synergistic design of current collector thickness, strength, and process window to balance energy density and mechanical reliability, providing a theoretical basis for stable manufacturing of high-specific-energy batteries.</p> Graphical abstract <p></p>