biostudies-literatureHou ZResearch Grants Council, University Grants CommitteeHong Kong Polytechnic UniversityNational Natural Science Foundation of ChinaNatural Science Foundation of Jiangsu Province1382-1389https://www.ebi.ac.uk/biostudies/studies/S-EPMC12933320biostudies-literatureUnknown6(2)Electrolyte chemistry is of paramount importance for tackling the challenge of irreversible Ca deposition/stripping caused by ionic-insulating solid electrolyte interphases (SEIs). Current research has been mainly concentrating on the boron center-based electrolytes despite their complex synthetic procedure and leaves aside others because of a virtually inhibited electrochemical response. Herein, we report a kind of iodine-based electrolytes comprising CaI₂ salt paired with auxiliary iodides, in which the latter elevates the I^- concentration to reconfigure electrical double-layer structures of a low-solubility CaI₂ electrolyte, thus accelerating Ca²⁺ desolvation and Ca²⁺ diffusion across SEI. Consequently, the optimized iodine electrolJACS AuIodine-Based Electrolyte Chemistry Enabling Reversible Ca Metal Anodes.PMC129333201-CE0H52125202BK20243016U24A20655240226715309324BK20241497Hou ZLiu KZhu JZhou RTsang CSZhao JZhang BfalseIodine-Based Electrolyte Chemistry Enabling Reversible Ca Metal Anodes.Electrolyte chemistry is of paramount importance for tackling the challenge of irreversible Ca deposition/stripping caused by ionic-insulating solid electrolyte interphases (SEIs). Current research has been mainly concentrating on the boron center-based electrolytes despite their complex synthetic procedure and leaves aside others because of a virtually inhibited electrochemical response. Herein, we report a kind of iodine-based electrolytes comprising CaI₂ salt paired with auxiliary iodides, in which the latter elevates the I^- concentration to reconfigure electrical double-layer structures of a low-solubility CaI₂ electrolyte, thus accelerating Ca²⁺ desolvation and Ca²⁺ diffusion across SEI. Consequently, the optimized iodine electrol2026-01-01T00:00:00Z2026 Feb2026-07-16T22:13:15.735Z2026-07-12T03:07:25.58ZS-EPMC129333204175584610.1021/jacsau.5c01724