Leave-Intercalation Theory and Conductive Mechanism during Charge-Discharge Process for Secondary Battery

Abstract

The source of conductive ions in the charge and discharge process of AB5/β-Ni(OH)2, 2H-graphite/ LiMeO2and 2H-graphite/LiFePO4batteries is thought to be provided by the phase transition of positive active materials, so it is called phase transition theory. Through the detailed study of the charge and discharge processes of AB5/β-Ni(OH)2, 2H-graphite/ Li(Ni1/3Co1/3Mn1/3)O2and 2H-graphite/LiFePO4, it is found that the source of conductive ions is the de-intercalation of H (nickel-hydrogen battery) and Li (lithium-ion battery) in positive and negative active materials, and the de-intercalation theory is proposed. On this basis, the conductive mechanisms of these three types of batteries are clarified: The directional migration and movement of conductive ions under the action of electric field