Identification of carbon surface functionalities leading to pseudocapacitance

对替代能源/存储系统的追求从未像现在这样激烈，而储能市场的一个强有力的竞争者是电化学电容器（EC）（或“超级电容器”）。EC是高功率能量存储装置，其可以独立使用或可以与低功率/高能量系统（例如燃料电池和电池）耦合以满足现代功率要求。此外，它们的长循环寿命（> 100万次循环）和基本免维护的事实使它们成为间歇性能源（例如风能和太阳能）和远程应用的理想电荷存储系统。它们还被用于车辆应用（例如负载平衡和冷启动辅助）和作为电源线备用。该研究项目的重点是鉴定不同的碳表面官能团（CSFs）（羟基，羧基，羰基，吡喃酮等）。存在于水性EC系统中使用的碳电极的表面上。这些CSF可以直接导致EC系统中更多的电荷存储（导致更高的能量系统）。将使用一些成熟的鉴别方法（Boehm滴定法和程序升温脱附法）鉴别CSF，这些方法虽然能够鉴别CSF，但无法提供有关这些物质是否可以添加到EC系统电荷储存中的信息。在这项研究中，这些方法将与强大的电化学和光谱（反射紫外-可见-近红外，红外和拉曼）技术相结合，以确定哪些CSF是增强电荷存储。此外，将使用电化学石英晶体微量天平（一种非常灵敏的技术，可记录质量的微克变化），以帮助识别这些CSF正在进行的反应，以将额外电荷储存在EC系统中。这项研究将大大提高利用碳电极的EC系统的储能能力，从而使EC成为一种更可行的储能商业选择。

The quest for alternative energy sources/storage systems has never been more vigorous than it is at present, and one strong contender for the energy storage market is the electrochemical capacitor (EC) (or "supercapacitor"). ECs are high power energy storage devices which can be used independently or can be coupled with low power/high energy systems (e.g. fuel cells and batteries) to satisfy modern day power requirements. Additionally, their long cycle life (> 1 000 000 cycles) and the fact that they are essentially maintenance free makes them ideal charge storage systems for intermittent energy sources (e.g. wind and solar power) and for remote applications. They have also been studied in vehicle applications (e.g. load-levelling and cold starting assistance) and as power line backup. This research project focuses on the identification of the different carbon surface functionalities (CSFs) (hydroxyl, carboxyl, carbonyl, pyrone, etc.) that exist on the surface of carbon electrodes used in aqueous EC systems. These CSFs can directly lead to more charge storage in the EC system (leading to a higher energy system). The identification of the CSFs will be undertaken by using some well established identification methods (Boehm's titration and Temperature Programmed Desorption), which while able to identify the CSFs, cannot provide information on whether these species can add to the charge-storage of the EC system. In this research, these methods will be coupled with powerful electrochemical and spectroscopic (Reflectance UV-Vis-NIR, IR and Raman) techniques to identify which of the CSFs is enhancing charge-storage. In addition, an Electrochemical Quartz Crystal Microbalance will be used (a very sensitive technique which allows for microgram changes in mass to be recorded) to help identify the reactions these CSF are undergoing to store the extra charge in the EC system. This research will greatly enhance the energy-storage abilities of EC systems that utilise carbon electrodes, and will thus make ECs a more viable commercial option for energy-storage.