Monitoring the Electrochemical Energy Storage Processes of an Organic Full Rechargeable Battery via Operando Raman Spectroscopy: A Mechanistic Study
Monitoring the Electrochemical Energy Storage Processes of an Organic Full Rechargeable Battery via Operando Raman Spectroscopy: A Mechanistic Study
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DOI：
10.1021/acs.chemmater.9b00077
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发表时间：
2019-05-14
影响因子：
8.6
通讯作者：
Fichtner, Maximilian
中科院分区：
文献类型：
--
作者：
Lin, Xiu-Mei;Wu, De-Yin;Fichtner, Maximilian
使用可源自生物质的有机化合物的绿色、可持续和多用途性质使它们成为用于各种可充电电池的非常有趣的材料。然而，由于缺乏能够真实的实时探测可充电电池系统的直接和可访问的分析技术，有机全可充电电池的整体电化学反应机理很少被报道。本文中，我们配置了由卟啉金属络合物[5，15-双（乙炔基）-10，20-二苯基卟啉]铜（II）（CuDEPP）阳极、石墨阴极和1-丁基-1-甲基哌啶鎓双（三氟甲磺酰基）酰亚胺（PP 14 TFSI）离子液体电解质组成的有机全可再充电电池。采用操作拉曼光谱同时监测电化学储能（EES）过程引起的电池阳极、阴极和电解质的拉曼谱带的演化。结果表明，在EES过程中，CuDEPP阳极的电子结构变化主要发生在卟啉环和乙炔基取代基上，而不是Cu（II）金属中心和苯取代基上，其次是与电解液中PP 14（+）阳离子的相互作用.此外，互补密度泛函理论（DFT）计算的阳极氧化还原反应机制进行和支持的光谱结果。同时，在阴极的EES过程中，TFSI-阴离子嵌入/脱嵌石墨阴极，导致1610 cm（-1）处G'谱带的出现和消失。我们的研究结果表明，有机阳极的共轭卟啉环和乙炔基取代基具有有利的氧化还原效应，支持充放电循环，并揭示了电极和电解质之间的相互作用，以更好地设计有机EES器件。
The green, sustainable, and versatile nature of using organic compounds that can be derived from biomass makes them extremely interesting materials for use in various rechargeable batteries. However, the overall electrochemical reaction mechanism of an organic full rechargeable battery has seldom been reported because of the lack of straightforward and accessible analytical techniques that capable of probing the rechargeable battery system in real time. Herein, we configured an organic full rechargeable battery composed of a porphyrin metal complex [5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) anode, a graphite cathode, and a 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) ionic liquid electrolyte. Operando Raman spectroscopy was employed to simultaneously monitor the evolution of Raman bands from the anode, cathode, and electrolyte of the battery caused by electrochemical energy storage (EES) processes. It was found that during EES processes, the electronic structural changes of the CuDEPP anode mainly occurred at the porphyrin ring and ethynyl substituent rather than at the Cu(II) metal center and benzene substituent, followed by interactions with PP14(+) cations of the electrolyte. Also, complementary density functional theory (DFT) calculations on the anode redox reaction mechanism were performed and support the spectroscopic results. Meanwhile, during EES processes at the cathode, TFSI- anions intercalated into/deintercalated out of the graphite cathode, which resulted in the appearance and disappearance of a G' spectral band at 1610 cm(-1). Our findings suggest the conjugated porphyrin ring and ethynyl substituent of the organic anode have a beneficial redox effect that supports charge-discharge cycling and reveals the interactions between the electrodes and electrolytes for the better design of organic EES devices.