An Anion-Concentrating Layer for a Large-Capacity Al Anode Enabled by an Amorphous 2D Covalent Organic Framework

TY - JOUR

T1 - An Anion-Concentrating Layer for a Large-Capacity Al Anode Enabled by an Amorphous 2D Covalent Organic Framework

AU - Li, Juan

AU - Nie, Wanli

AU - Ryazantsev, Sergey

AU - Zhang, Liping

AU - Zhu, Yanan

AU - Guo, Shaohua

AU - Gu, Sichen

AU - Wu, Chuan

N1 - Publisher Copyright: © 2026 Wiley-VCH GmbH.

PY - 2026/5/26

Y1 - 2026/5/26

N2 - Rechargeable aluminum batteries suffer from dendritic anode growth and capacity decay due to severe concentration polarization caused by sluggish ion transport kinetics, particularly under high-capacity conditions. To address this issue, we developed an amorphous covalent organic framework (COF) coating layer engineered for anion-concentrating functionality. The conformational flexible imine linkages in the amorphous COF enable adaptive trapping of Al2Cl7−, storing them as crystalline AlCl3 and ligand-bonded AlCl4− within the mesopores. This mechanism enriches electrochemical active species to buffer the concentration polarization, and promotes the formation of highly active Al3Cl10− species at the surface, thereby accelerating interfacial kinetics to guide homogeneous deposition. As a result, dendrite-free aluminum deposition is achieved even at an ultrahigh areal capacity of 10 mAh cm−2 under the protection of the COF. The half-cell with the COF exhibits an exceptional cycling time of over 6000 h with a coulombic efficiency of 99.9%, while symmetric cells demonstrate long-term stability over 7500 h with a low overpotential of 36 mV. Full cells with the graphite cathode also maintain stability over 5000 cycles under a large current density of 1.2 A g−1. This work presents an effective coating strategy for regulating electrodeposition in metal anode batteries, highlighting a promising path toward practical applications.

AB - Rechargeable aluminum batteries suffer from dendritic anode growth and capacity decay due to severe concentration polarization caused by sluggish ion transport kinetics, particularly under high-capacity conditions. To address this issue, we developed an amorphous covalent organic framework (COF) coating layer engineered for anion-concentrating functionality. The conformational flexible imine linkages in the amorphous COF enable adaptive trapping of Al2Cl7−, storing them as crystalline AlCl3 and ligand-bonded AlCl4− within the mesopores. This mechanism enriches electrochemical active species to buffer the concentration polarization, and promotes the formation of highly active Al3Cl10− species at the surface, thereby accelerating interfacial kinetics to guide homogeneous deposition. As a result, dendrite-free aluminum deposition is achieved even at an ultrahigh areal capacity of 10 mAh cm−2 under the protection of the COF. The half-cell with the COF exhibits an exceptional cycling time of over 6000 h with a coulombic efficiency of 99.9%, while symmetric cells demonstrate long-term stability over 7500 h with a low overpotential of 36 mV. Full cells with the graphite cathode also maintain stability over 5000 cycles under a large current density of 1.2 A g−1. This work presents an effective coating strategy for regulating electrodeposition in metal anode batteries, highlighting a promising path toward practical applications.

KW - Al anode

KW - aluminum-ion battery

KW - amorphous materials

KW - covalent organic frameworks

KW - large capacity

UR - https://www.scopus.com/pages/publications/105033034290

U2 - 10.1002/adfm.202600038

DO - 10.1002/adfm.202600038

M3 - Article

AN - SCOPUS:105033034290

SN - 1616-301X

VL - 36

JO - Advanced Functional Materials

JF - Advanced Functional Materials

IS - 42

M1 - e00038

ER -