Electrically Insulating Rigid Multi-Channel Electrolyte Container for Customizable Electron Transfer in Zn-Halogen Batteries
Yifan Zhou, Yicai Pan, Yongqiang Yang, Taghreed F. Altamimi, Yunpeng Zhong, Dalal A. Alshammari, Zeinhom M. El‐Bahy, Shuquan Liang, Jiang Zhou, Xinxin Cao
Abstract
Abstract Recent advancements in Zn-halogen batteries have focused on enhancing the adsorptive or catalytic capability of host materials and stabilizing complex intermediates with electrolyte additives, while the halogen-ion electrolyte modifications exhibit strong potential for integrated interfacial regulation. Herein, we design an electrically insulating rigid electrolyte container to immobilize a liquid halogen-ion electrolyte for separator-free Zn-halogen batteries with customizable electron transfer. Robust hydrogen bonding of hydroxyl groups in SiO 2 with fluorinated moieties in PVDF- hfp regulates Zn 2+ solvation and suppresses H 2 O activity, while multi-channels formed by microcracks and interparticle gaps not only enhance mass transfer but also buffer interfacial electric field, jointly enabling a durable Zn plating/stripping. Effective confinement of intermediates also ensures the high reversibility across single-(I − /I 0 ), double-(I − /I 0 /I⁺), and triple-(I − /I 0 /I⁺, Cl − /Cl 0 ) electron transfer mechanisms at cathode, as evidenced by the double-electron transfer systems exhibiting a low capacity decay rate of 0.02‰ over 4500 cycles at 10 mA cm −2 and a high areal capacity of 11.9 mAh cm −2 at 2 mA cm −2 . This work presents a novel “container engineering” approach to halogen-ion electrolyte design and provides fundamental insights into the relationships between redox reversibility and reaction kinetics.