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

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 Mn²⁺, 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 Mn²⁺, thereby providing excellent electrochemical performance. Furthermore, both in situ and ex situ characterizations elucidated the Zn²⁺ 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.

Keywords: anthraquinone; aqueous batteries; location effect; machine learning; reaction mechanism.