Journal of Power Sources 499 (2021) 229968 Available online 3 May 2021 0378-7753/© 2021 Elsevier B.V. All rights reserved. Ion-conductive self-healing polymer network based on reversible imine bonding for Si electrodes Jaebin Nam a, b , Wonseok Jang a, b , Rajeev K.K. a, b , Ji-Hyun Lee c , Yeonho Kim b , Tae-Hyun Kim a, b, * a Organic Material Synthesis Laboratory, Department of Chemistry, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, South Korea b Research Institute of Basic Sciences, Incheon National University, Incheon, 22012, South Korea c Electron Microscopy Research Center, Korea Basic Science Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon, 34133, Republic of Korea HIGHLIGHTS G R A P H I C A L ABSTRACT • An ion-conductive self-healing polymer binder is developed for high- performance Si anode. • Polymer network based on reversible imine bonds provides self-healing property. • Enhanced electrochemical performances are obtained with the developed poly- mer binder. A R T I C L E INFO Keywords: Reversible covalent-bonding polymer network Self-healing polymer binder Chemical crosslinking Ion conductivity Silicon electrodes ABSTRACT Si electrodes have attracted considerable attention as materials for next-generation lithium-ion batteries owing to their high theoretical capacity and natural abundance. However, many limitations must be overcome before Si electrodes can be commercialized, particularly the steady degradation in battery performance caused by large volume changes in the active material. Here, an ion-conductive self-healing polymer binder is developed for high-performance silicon electrodes. Glycol chitosan with dialdehyde-terminated polyethylene glycol as a macro- crosslinker is used in a simple process to form the crosslinked polymer network based on imine double bonds, which further improves ion conductivity. Strong and reversible imine double bonds in the crosslinked polymer provide self-healing ability. Si electrodes using the developed polymer network results in an initial Coulombic effciency of 82.2%, a discharge capacity of 2141 mAh g 1 after 150 cycles, and a reversible capacity of 2700 mAh g 1 at a current density of 3C. These outstanding electrochemical performances demonstrate that the self- healable network and ion-conductive functionality of the developed polymeric binder signifcantly improves the operation of Si electrodes. * Corresponding author. Organic Material Synthesis Laboratory, Department of Chemistry, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, South Korea. E-mail address: tkim@inu.ac.kr (T.-H. Kim). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour https://doi.org/10.1016/j.jpowsour.2021.229968 Received 18 December 2020; Received in revised form 16 March 2021; Accepted 23 April 2021