Ma Jingkang, Azizi Alireza, Zhang Erhuan, Zhang Hong, Pan Anqiang, Lu Ke
Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University Hefei Anhui 230601 China
School of Chemistry and Chemical Engineering, Harbin Institute of Technology Harbin Heilongjiang 150001 China
Chem Sci. 2024 Feb 23;15(12):4581-4589. doi: 10.1039/d4sc00276h. eCollection 2024 Mar 20.
The realization of high energy is of great importance to unlock the practical potential of zinc-iodine batteries. However, significant challenges, such as low iodine loading (mostly less than 50 wt%), restricted iodine reutilization, and severe structural pulverization during cycling, compromise its intrinsic features. This study introduces an optimized, fully zincified zinc iodide loaded onto a hierarchical carbon scaffold with high active component loading and content (82 wt%) to prepare a thick cathode for enabling high-energy Zn-I batteries. The synergistic interactions between nitrogen heteroatoms and cobalt nanocrystals within the porous matrix not only provide forceful chemisorption to lock polyiodide intermediates but also invoke the electrocatalytic effects to manipulate efficient iodine conversion. The ZnI cathode could effectively alleviate continuous volumetric expansion and maximize the utilization of active species. The electrochemical examinations confirm the thickness-independent battery performance of assembled Zn-I cells due to the ensemble effect of composite electrodes. Accordingly, with a thickness of 300 μm and ZnI loading of up to 20.5 mg cm, the cathode delivers a specific capacity of 92 mA h g after 2000 cycles at 1C. Moreover, the Zn-I pouch cell with ZnI cathode has an energy density of 145 W h kg as well as a stable long cycle life.
实现高能量对于释放锌碘电池的实际潜力至关重要。然而，诸如低碘负载量（大多低于50 wt%）、碘再利用受限以及循环过程中严重的结构粉化等重大挑战，损害了其固有特性。本研究引入了一种优化的、完全锌化的碘化锌，负载在具有高活性成分负载量和含量（82 wt%）的分级碳支架上，以制备用于实现高能锌碘电池的厚阴极。多孔基质中氮杂原子与钴纳米晶体之间的协同相互作用不仅提供强力化学吸附以锁定多碘化物中间体，还引发电催化效应以操控高效的碘转化。ZnI阴极可有效缓解持续的体积膨胀并最大化活性物种的利用率。电化学测试证实，由于复合电极的整体效应，组装的锌碘电池的性能与阴极厚度无关。因此，阴极厚度为300μm且ZnI负载量高达20.5 mg cm时，在1C下循环2000次后，其比容量为92 mA h g。此外，具有ZnI阴极的锌碘软包电池的能量密度为145 W h kg，且具有稳定的长循环寿命。
