Su Jingwen, Zhang Meng, Tian Hao, Han Mingshan, Sun Zhaopeng, Du Kai, Cui Fangyan, Li Jingzhen, Huang Weiwei, Hu Yuxiang
Key Laboratory of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing, 100124, China.
Hebei Key Laboratory of Applied Chemistry, Yanshan University, Qinhuangdao, 066004, China.
Small. 2024 Jul;20(29):e2312086. doi: 10.1002/smll.202312086. Epub 2024 Feb 27.
Rechargeable aqueous aluminum batteries (AABs) are promising energy storage technologies owing to their high safety and ultra-high energy-to-price ratio. However, either the strong electrostatic forces between high-charge-density Al and host lattice, or sluggish large carrier-ion diffusion toward the conventional inorganic cathodes generates inferior cycling stability and low rate-capacity. To overcome these inherent confinements, a series of promising redox-active organic materials (ROMs) are investigated and a π-conjugated structure ROMs with synergistic C═O and C═N groups is optimized as the new cathode in AABs. Benefiting from the joint utilization of multi-redox centers and rich π-π intermolecular interactions, the optimized ROMs with unique ion coordination storage mechanism facilely accommodate complex active ions with mitigated coulombic repulsion and robust lattice structure, which is further validated via theoretical simulations. Thus, the cathode achieves enhanced rate performance (153.9 mAh g at 2.0 A g) and one of the best long-term stabilities (125.7 mAh g after 4,000 cycles at 1.0 A g) in AABs. Via molecular exploitation, this work paves the new direction toward high-performance cathode materials in aqueous multivalent-ion battery systems.
可充电水系铝电池（AABs）因其高安全性和超高的能量价格比而成为很有前景的储能技术。然而，高电荷密度的铝与主体晶格之间的强静电力，或者向传统无机阴极缓慢扩散的大载流子离子，都会导致较差的循环稳定性和低倍率容量。为了克服这些固有限制，研究了一系列有前景的氧化还原活性有机材料（ROMs），并优化了一种具有协同C═O和C═N基团的π共轭结构ROMs作为AABs中的新型阴极。受益于多氧化还原中心的联合利用和丰富的π-π分子间相互作用，具有独特离子配位存储机制的优化ROMs能够轻松容纳复杂的活性离子，减轻库仑排斥力并具有坚固的晶格结构，这一点通过理论模拟得到了进一步验证。因此，该阴极在AABs中实现了增强的倍率性能（在2.0 A g时为153.9 mAh g）和最佳的长期稳定性之一（在1.0 A g下4000次循环后为125.7 mAh g）。通过分子探索，这项工作为水系多价离子电池系统中高性能阴极材料开辟了新方向。
