北京大学郭少军团队报道了稳定的I··H-O分子内卤素键，促进可持续钾碘电池的可逆I^3- /I^-氧化还原行为。相关研究成果于2024年12月26日发表于国际一流学术期刊《美国化学会杂志》。

由于其高功率密度和环境可持续性，钾碘电池作为下一代电池技术的替代品显示出巨大的前景。然而，它们受到聚碘化物溶解和多步电极制造工艺的影响，导从而致了严重的性能下降和大众市场采用的限制。

该文中，研究人员报告了一种简单的“溶液-吸附”策略，用于扩大生产Ti₃C₂（OH）_x包裹的碳纳米管纸（CNP），作为加强碘封装的经济主体。前沿表征和理论计算结果表明，CNP对电化学活性的I^3-/I^-氧化还原对表现出很强的亲和力，而MXene上的Ti-OH官能团通过形成稳定的I··H-O分子内卤素键来限制聚碘化物的溶解。

受益于这种协同效应，独立电极确保了开发高性能碘化钾电池的可逆氧化还原化学。制造的袋式电池（100 mAh）显示出高能量密度（130 Wh kg^–1），满充/放电时间为10分钟，优于需要高能量/功率密度的最先进的新电池系统。这种钾碘电池将成本降低到255美元kWh^-1，远低于锂离子电池中的阴极材料，为电网规模的储能提供了可持续的选择。

附：英文原文

Title: Robust I···H–O Intramolecular Halogen Bond Boosts Reversible I3–/I– Redox Behavior for Sustainable Potassium–Iodine Batteries

Author: Shuoqing Zhao, Bohan Zhang, Lu Li, Peng Zhang, Guohao Li, Zhenyu Zhu, YoonJeong Choi, Liubing Dong, Mingchuan Luo, Shaojun Guo

Issue&Volume: December 26, 2024

Abstract: Potassium–iodine batteries show great promise as alternatives for next-generation battery technology, owing to their high power density and environmental sustainability. Nevertheless, they suffer from polyiodide dissolution and the multistep electrode fabrication process, which leads to severe performance degradation and limitations in mass-market adoption. Herein, we report a simple “solution–adsorption” strategy for scale-up production of Ti3C2(OH)x-wrapped carbon nanotube paper (CNP), as an economic host for strengthening the iodine encapsulation. The cutting-edge characterizations and theoretical calculation results reveal that CNP exhibits great affinity to the electrochemically active I3–/I– redox couple, while the Ti–OH functional groups on MXene restrict the dissolution of polyiodides through forming the stable I···H–O intramolecular halogen bond. Benefiting from such a synergistic effect, the free-standing electrode ensures the reversible redox chemistry for developing high-performing potassium–iodine batteries. The fabricated pouch cell (100 mAh) shows a high energy density (130 Wh kg–1) with a full charge/discharge of 10 min, outperforming state-of-the-art new battery systems that require both high energy/power density. Such a potassium–iodine battery reduces the cost to 255 US$ kW h–1, which is much lower than that of the cathode materials in lithium-ion batteries and offers a sustainable option for grid-scale energy storage.

DOI: 10.1021/jacs.4c12960

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c12960