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Vol. 18 (2026)

“Proton-Iodine” Regulation of Protonated Polyaniline Catalyst for High-Performance Electrolytic Zn-I2 Batteries

https://doi.org/10.1007/s40820-025-01928-5
Mengyao Liu
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Kovan Khasraw Abdalla
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Meng Xu
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Xueqian Li
Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, People’s Republic of China
Runze Wang
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Qi Li
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Xiaoru Zhang
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Yanan Lv
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Yueyang Wang
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Xiaoming Sun
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China
Yi Zhao
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China

Corresponding Author: Yi Zhao

zybattery@buct.edu.cn

Nano-Micro Letters, Vol. 18 (2026), Article Number: 79

Abstract

Low-cost and high-safety aqueous Zn-I2 batteries attract extensive attention for large-scale energy storage systems. However, polyiodide shuttling and sluggish iodine conversion reactions lead to inferior rate capability and severe capacity decay. Herein, a three-dimensional polyaniline is wrapped by carboxyl-carbon nanotubes (denoted as C-PANI) which is designed as a catalytic cathode to effectively boost iodine conversion with suppressed polyiodide shuttling, thereby improving Zn-I2 batteries. Specifically, carboxyl-carbon nanotubes serve as a proton reservoir for more protonated –NH+ = sites in PANI chains, achieving a direct I0/I− reaction for suppressed polyiodide generation and Zn corrosion. Attributing to this “proton-iodine” regulation, catalytic protonated C-PANI strongly fixes electrolytic iodine species and stores proton ions simultaneously through reversible –N = /–NH+– reaction. Therefore, the electrolytic Zn-I2 battery with C-PANI cathode exhibits an impressive capacity of 420 mAh g−1 and ultra-long lifespan over 40,000 cycles. Additionally, a 60 mAh pouch cell was assembled with excellent cycling stability after 100 cycles, providing new insights into exploring effective organocatalysts for superb Zn-halogen batteries.


Highlights:
1 A three-dimensional polyaniline wrapped by carboxyl-carbon nanotubes (denoted as C-PANI) is designed as a catalytic cathode to effectively boost direct I0/I− conversion for improved Zn-I2 batteries.
2 Carboxyl-carbon nanotubes serve as a proton reservoir for more protonated –NH+ = sites in PANI chains, achieving “proton-iodine” regulation for suppressed polyiodide shuttling and Zn corrosion.
3 Electrolytic Zn-I2 battery with C-PANI cathode exhibits an impressive capacity of 420 mAh g−1 and ultra-long lifespan over 40,000 cycles.








Keywords

Electrolytic Zn-I2 battery Proton-iodine regulation Direct I0/I− reaction conversion Limited polyiodide shuttling High performance
Liu, Mengyao, Kovan Khasraw Abdalla, Meng Xu, Xueqian Li, Runze Wang, Qi Li, Xiaoru Zhang, Yanan Lv, Yueyang Wang, Xiaoming Sun, and Yi Zhao. 2025. “‘Proton-Iodine’ Regulation of Protonated Polyaniline Catalyst for High-Performance Electrolytic Zn-I2 Batteries”. Nano-Micro Letters 18 (November):79. https://doi.org/10.1007/s40820-025-01928-5.
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