This study presents a novel method to separate positive electrode active materials (PEAMs) and aluminum (Al) foil from positive electrodes (PEs) to enable more effective recycling processes. A pulsed current was applied to a PE sample that was prepared by manual dismantlement of spent lithium-ion batteries (LiBs). Joule heating caused the temperature of the Al foil to increase to be above the melting points of adhesion included in the PEAMs. The influence of the surrounding medium of the PE sample on the delamination phenomenon was investigated. PEAMs were peeled from the Al foil in water and air environments. High-speed visible imaging was employed to discuss separation processes. Differences in the size of the separated PEAMs and the amount of residual PEAM on the surface of the Al foil occurred due to the influence of the medium filled in the voids inside the PEAM layer.