扬帆启航：电化学实验初步

电化学是研究电能和化学能相互转化的规律的科学。电能和化学能之间的相互转换,是通过电极/电解质溶液表界面的结构变化和电荷转移反应来实现的。以电化学能源器件为例,前者为超级电容器,能量存储和释放主要通过界面双电层的表界面结构变化来实现;后者为化学电源,能量存储和释放主要通过电极活性物质的表界面化学反应来实现。所以,研究一个电化学体系时,主要关注两个问题,即表界面结构和表界面电荷转移反应。而表界面结构直接影响表界面电荷转移反应的性质,因此,从电化学实验的角度,表界面的构筑是至关重要的,包括电极的制备和表征、电极修饰材料的制备及组装、溶剂和支持电解质的选择和优化、电化学实验环境等等。本文旨在向广大电化学初学者讲述电化学实验的准备工作以及对实验现场数据的基本判断,帮助大家在实验中及时发现问题,及早采取措施,高效率地获取可信的实验数据。

Sailing to the Ocean of Electrochemistry:the First Step of Experiment

Electrochemistry is the science on the conversion between chemical energy and electric energy, which is realized by the structure change of the electrified surface and interface, and/or the surface and interfacial charge transfer reactions. Taking the electrochemical energy devices as example, the former is the supercapacitor where the energy storage and release are performed by the structure change of the electric double layer; the latter is the battery where the energy storage and release are performed by the redox reaction of the electrode active materials. When investigating an electrochemical system, we have to pay attentions to two issues: the surface and interfacial structures and the charge transfer reactions wherein, and the former has crucial effects on the properties of the latter. Thus, the design and construct of electrode surface and interface are essential in electrochemical experiments, including the preparation and characterization of electrode, the modification and assembly of composite electrode, the choice and optimization of solvent and supporting electrolyte, the experimental environment, etc. The purpose of this paper is to give introductions on the preparations of electrochemical experiments and to help the juniors to judge the quality of experimental data. This would be helpful for the improvements of data reliability and work efficiency.