Role of the Anion on the Transport and Structure of Organic Mixed Conductors
Role of the Anion on the Transport and Structure of Organic Mixed Conductors
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DOI：
10.1002/adfm.201807034
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发表时间：
2019-02-01
影响因子：
19
通讯作者：
Rivnay, Jonathan
中科院分区：
文献类型：
--
作者：
Cendra, Camila;Giovannitti, Alexander;Rivnay, Jonathan
有机混合导体越来越多地用于在水溶液中操作的电化学装置中，其利用离子和电子的同时传输。事实上，它们的工作模式依赖于通过离子迁移来改变它们的掺杂（氧化）状态，以补偿电子电荷。然而，当离子和水渗透材料时，有机混合导体经历的结构和形态变化尚未完全了解。通过电化学、重量分析和结构表征的组合，阐明了水和阴离子对亲水性共轭聚合物的影响。使用一系列不同的阴离子大小，水合壳，和酸度的钠离子水溶液盐，阴离子的性质和运输和聚合物的结构性质之间的联系进行了系统的研究。在掺杂时，离子插入微晶中，永久地改变晶格间距，并且残留的水使膜溶胀。然而，聚合物保持电化学可逆性。电化学晶体管的性能表明，掺杂更大，更少的水合，阴离子增加了它们的电导率，但降低了开关速度。这项研究强调了电解质混合导体相互作用的复杂性，并推进了材料设计，强调了聚合物和电解质（溶剂和离子）在器件性能中的耦合作用。
Organic mixed conductors are increasingly employed in electrochemical devices operating in aqueous solutions that leverage simultaneous transport of ions and electrons. Indeed, their mode of operation relies on changing their doping (oxidation) state by the migration of ions to compensate for electronic charges. Nevertheless, the structural and morphological changes that organic mixed conductors experience when ions and water penetrate the material are not fully understood. Through a combination of electrochemical, gravimetric, and structural characterization, the effects of water and anions with a hydrophilic conjugated polymer are elucidated. Using a series of sodium-ion aqueous salts of varying anion size, hydration shells, and acidity, the links between the nature of the anion and the transport and structural properties of the polymer are systematically studied. Upon doping, ions intercalate in the crystallites, permanently modifying the lattice spacings, and residual water swells the film. The polymer, however, maintains electrochemical reversibility. The performance of electrochemical transistors reveals that doping with larger, less hydrated, anions increases their transconductance but decreases switching speed. This study highlights the complexity of electrolyte-mixed conductor interactions and advances materials design, emphasizing the coupled role of polymer and electrolyte (solvent and ion) in device performance.