Stable High-Capacity Organic Aluminum-Porphyrin Batteries
Stable High-Capacity Organic Aluminum-Porphyrin Batteries
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DOI：
10.1002/aenm.202101446
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发表时间：
2021-06-27
影响因子：
27.8
通讯作者：
Jiao, Shuqiang
中科院分区：
文献类型：
--
作者：
Han, Xue;Li, Shijie;Jiao, Shuqiang
铝离子电池（AIB）因其上级安全性和长寿命能量存储的有前途的特性而引起人们的兴趣。具有工程活性基团的有机材料被认为有希望促进能量存储能力。然而，相应的能量密度（需要电压平台和足够的活性位点两者）和稳定性仍然出乎意料地差。为了解决这些挑战，本文选择π-共轭有机卟啉分子，即5，10，15，20-四苯基卟啉（H2 TPP）和5，10，15，20-四（4-羧基苯基）卟啉（H2 TCPP）作为AIB的正极材料。由于与铝络合物阳离子的高度可逆的配位/解离，H2 TPP在200 mA g（-1）下具有超过5000次循环的长期循环稳定性。与H2 TCPP的比容量（在100 mA g（-1）下约为24 mA h g（-1））相比，H2 TPP的增强的容量（在100 mA g（-1）下约为101 mA h g（-1））归因于羧基官能团的去除，这在通过吸电子效应诱导的降低卟啉的碱性中起作用。此外，还研究了AlCl ~（2+）与卟啉的电化学反应机理以及在电极表面的离子扩散行为。研究结果为开发长期安全稳定储能的有机铝电池奠定了基础。
Aluminum-ion batteries (AIBs) attract interest for their promising features of superior safety and long-life energy storage. Organic materials with engineered active groups are considered promising for promoting energy storage capabilities. However, the corresponding energy density (both voltage plateau and sufficient active sites required) and stability are still unexpectedly poor. To address these challenges, here pi-conjugated organic porphyrin molecules, that is, 5,10,15,20-tetraphenylporphyrin (H2TPP) and 5,10,15,20-tetrakis(4-carboxyphenyl) porphyrin (H2TCPP), are selected as the positive electrode materials for AIBs. Owing to the highly reversible coordination/dissociation with aluminum complex cations, H2TPP presents long-term cycling stability beyond 5000 cycles at 200 mA g(-1). Compared with the specific capacity of H2TCPP (approximate to 24 mA h g(-1) at 100 mA g(-1)), the enhanced capabilities in H2TPP (reversible specific capacity of approximate to 101 mA h g(-1) at 100 mA g(-1)) are attributed to removal of the carboxyl functional groups, which plays a role in reducing the basicity of porphyrin induced via electron withdrawing effects. Additionally, the mechanism of electrochemical reaction between AlCl2+ and porphyrin as well as ionic diffusion behaviors on the surface of the electrode are investigated. The results establish a platform to develop long-term organic aluminum batteries for safe and stable energy storage.