Preface for the 73rd Special Feature “Progress in Aqueous Battery Research”

This special issue of Electrochemistry features content based on recent advances in aqueous battery research, chiefly consisting of papers presented in the 4th International Zinc and other Aqueous Batteries Workshop (IZABW4), held in September 2025 at Uji Campus of Kyoto University, Japan.There were 116 attendees from 7 countries with 26 oral and 36 poster presentations at IZABW4, sharing knowledge and promoting discussion on zinc, MnO2 and air (oxygen) electrodes, electrolytes as well as cell/system fabrication.The local organizing committee members hope that this collection stimulates further innovation in the aqueous battery research.