Qi Bei, Chai Yongping, Hu Yajie, Liu Zhengyao, Wang Yan, Chen Kang, Tan Chaoran, Bai Xinyu, Xie Kefeng, Cheng Huhu, Chi Xiaodong, Huang Liang, Qu Liangti
Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, P.R. China.
School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P.R. China.
Angew Chem Int Ed Engl. 2025 Aug 11;64(33):e202507497. doi: 10.1002/anie.202507497. Epub 2025 Jun 18.
Zinc-iodine batteries offer great potential for energy storage due to their long-term cycle stability, flat voltage plateau, inherent safety, and cost-effectiveness. However, their performance is limited by capacity fading and low Coulombic efficiency (CE) caused by the I shuttle effect. In this work, we propose a molecularly engineered tetrazine derivative, 3,6-bis(2-morpholinoethyl)-1,2,4,5-tetrazine (BMT) as a multifunctional cathode to address these challenges. BMT exhibits a reversible two-electron redox process, boosting charge storage capacity, and forms stable precipitation with I ions at a 1:2 stoichiometric ratio, effectively inhibiting the shuttle of polyiodide by covalent-electrostatic synergistic confinement. As expected, the BMT-based cathode exhibits a CE of 99.6% at 2 A g, a high specific discharge capacity of 207 mAh g at 0.5 A g as well as ∼100% capacity retention over 33 000 cycles at 2 A g, achieving a record iodine anchoring efficiency. Furthermore, the Zn-I pouch cell with high iodine mass loading (15.5 mg cm) delivers a practical cathode energy density of 145.2 Wh kg and maintains 76.2% of its capacity after 800 cycles at 2 A g. This work presents a mechanism-driven cathode design strategy that integrates redox activity and polyiodide confinement, providing a blueprint for the development of stable iodine-based batteries.
锌碘电池因其长期循环稳定性、平坦的电压平台、固有安全性和成本效益，在能量存储方面具有巨大潜力。然而，其性能受到碘穿梭效应导致的容量衰减和低库仑效率（CE）的限制。在这项工作中，我们提出一种分子工程化的四嗪衍生物，即3,6-双（2-吗啉代乙基）-1,2,4,5-四嗪（BMT）作为多功能阴极来应对这些挑战。BMT展现出可逆的双电子氧化还原过程，提高了电荷存储容量，并与碘离子以1:2的化学计量比形成稳定沉淀，通过共价-静电协同限制有效地抑制了多碘化物的穿梭。正如预期的那样，基于BMT的阴极在2 A g下的CE为99.6%，在0.5 A g下具有207 mAh g的高比放电容量，以及在2 A g下33000次循环中约100%的容量保持率，实现了创纪录的碘锚定效率。此外，具有高碘质量负载（15.5 mg cm）的锌碘软包电池在2 A g下的实际阴极能量密度为145.2 Wh kg，在800次循环后仍保持其容量的76.2%。这项工作提出了一种机制驱动的阴极设计策略，该策略整合了氧化还原活性和多碘化物限制，为开发稳定的碘基电池提供了蓝图。
