Professor Ma Mingguo's team from the College of Materials Science and Technology at Beijing Forestry University has recently achieved a breakthrough in high-energy-density zinc-iodine batteries. Their study, titled "A MXene Modulator Enabled High-Loading Iodine Composite Cathode for Stable and High-Energy-Density Zn-I₂ Battery", was published in the top-tier Journal Advanced Energy Materials (IF=24.4).

Achieving both high iodine loading cathode and high Zn anode depth of discharge (DOD) is pivotal to unlocking the full potential of energy-dense Zn-I2 batteries. However, this combination exacerbates the detrimental shuttle effect of polyiodide intermediates, significantly impairing the battery's reversibility and stability. Herein, this study reports an advanced high-loading iodine cathode (denoted as MX-AB@I) enabled by a multifunctional Ti3C2Tx MXene modulator, which presents high stability and energy density in Zn-I2 batteries. Through comprehensive experimental and theoretical analyses, the intrinsic regulating mechanisms are elucidated by which the MXene modulator effectively suppresses polyiodide shuttling, enhances iodine conversion kinetics, and dramatically improves Zn anode reversibility. With the aid of the MXene modulator, the MX-AB@I composite cathode achieves a high iodine mass loading of 23 mg cm−2 and realizes a practically high areal capacity of 4.0 mAh cm−2. When paired with a thin Zn anode (10 µm), this configuration realizes a high Zn DOD of 78.7% and a high energy density of 171.3 Wh kg−1, surpassing the majority of Zn-I2 battery systems reported in the literature. This study presents an effective approach to designing high-loading iodine cathodes for Zn-I2 batteries by leveraging MXene modulators to regulate critical electrochemical reaction processes.

Li Dandan, a doctoral student at the College of Materials Science and Technology, is the first author of the paper. The corresponding authors are Professor Ma Mingguo from BFU, Researcher Zhu Yingjie and Associate Researcher Li Heng from the Shanghai Institute of Ceramics, Chinese Academy of Sciences, and Dr. Zhang Wei from University College London. BFU is the signature unit of the paper.

This study was financially supported by the National Natural Science Foundation of China (Grant No. 52202328, 52372099, 22478036), the Shanghai Sailing Program (22YF1455500), and BeiJing Nova Program (20230484431).

Paper link: https://doi.org/10.1002/aenm.202404426

Written by Li Dandan, Ma Mingguo
Translated and edited by Song He
Reviewd by Yu Yangyang