Ion-Conductive Self-Healing Polymer Network Based on Reversible Imine Bonding for Si Electrodes

Abstract

Lithium-ion battery (LIB), one of the most promising energy storage devices due to higher energy density than other secondary batteries, have continuously developed, and their market has been growing steadily. Currently, the efforts have been produced for using LIB in electric vehicles (EVs) and energy storage systems (ESS) storage beyond small portable devices. Higher energy density and faster charge/discharge rate are required for the practical application of LIB to these large-scale energy devices, and new materials to meet these requirements are hence necessary. Silicon has been reported as an anode material for the next-generation LIB due to its outstanding theoretical capacity and natural abundance. However, there are many limitations in practical application due to the continuous deterioration of the battery performances by enormous volume change of this active material. These problems are mainly originated from the structural deterioration of the electrode causing loss of conductive pathway and the active area for the electrode. Hence, many approaches to securing the structural stability of the Si electrode through various methods, including polymeric binders with good adhesion with Si were developed.In this study, self-healable polymeric binder was designed through a crosslinking polymer network using a reversible imine chemistry. Additionally, the ion conductive polymer was introduced to improve ion conductivities of this self-healable binder. The synthesis, characterization and the electrical properties of the proposed polymeric binder for high-performance silicon electrodes will be discussed in detail.