Manganese–Based Metal–Organic Coordination for Aqueous Zinc–Ion Batteries With Varying Mechanical Adaptability and Machine Learning–Assisted Performance Decoding

Abstract

Abstract Aqueous zinc–ion batteries (AZIBs) have garnered significant attention owing to their high safety and low cost; however, their development is hindered by the poor cycling stability and low capacity of traditional inorganic cathode materials. This study innovatively utilizes dihydroxy/diamino anthraquinone (DHAQ/DAAQ) ligands featuring π–conjugated systems and quinone–based redox activity. By precisely regulating the substitution sites (1,2–/1,4–/1,5–) and coordinating them with Mn 2+ , layered flower−cluster Manganese–based metal–organic coordination is successfully constructed. The experimental results indicated that in the Mn−1,4−DHAQ cathode, the symmetric structure of the 1,4–dihydroxy substitution promoted electron delocalization and formed stable coordination bonds with Mn 2+ , thereby providing excellent electrochemical performance. Furthermore, both in situ and ex situ characterizations elucidated the Zn 2+ storage mechanism during charge–discharge processes. Notably, this work incorporated machine learning techniques to develop a specific capacity prediction model, laying a methodological foundation for future research in the field of energy storage. Theoretical calculations are employed to gain deeper insight into the underlying reasons for the outstanding performance of Mn−1,4−DHAQ. In addition, Mn−1,4−DHAQ is successfully applied as a cathode material in soft−pack batteries, gel electrolyte devices, and screen−printed devices, demonstrating excellent mechanical adaptability and practical application potential. Novel strategy for high−performance MOC–based AZIBs boosts practical energy storage applications.