Fundamental and Practical Studies of Capacitive Deionization Using Asymmetric Nanoporous Oxide Electrodes

[852780]电容去离子（CDI）是一种通过在带电表面附近的电双层中隔离离子来操作的过程。从本质上讲，离子溶液流经多孔导电对电极，阴离子或其他带负电荷的物质在正极被除去，而阳离子或带正电荷的物质在负极从溶液中分离出来。在去除过程中，能量以电容方式存储，并且可以随时获得，以降低能耗成本。在充电循环中，施加反向偏压，迫使电化学隔离的离子以盐水的形式释放出来，就像反渗透和蒸发蒸馏过程一样。通常认为，CDI的卤水产量低于RO作业。该提案包括使用一种新型不对称电极包覆纳米多孔氧化物的CDI工艺的基础和实践研究。本研究将利用电化学阻抗测量和与现实世界孔径和孔径分布相关的模型来解释我们的结果。此外，还将开发一种原位电化学FTIR系统来研究这些纳米多孔氧化物电极内部的分子行为。从实际的角度来看，许多对CDI电极必须串联工作，电子控制，并匹配水的成分和通量，以获得最佳的离子去除。在这部分的研究中，一堆电极将被组装成一个模块，并对离子去除与时间、电极表面积和每加仑水处理的能源成本进行基准测试。这部分拟开展的工作将分四部分完成：1.工作内容：为我们的电极选择最佳的支撑材料。用我们最好的纳米多孔氧化物薄膜涂在这个支架上。3. 测试电极在四对堆叠，最后4。构建CDI原型。作为一种海水淡化工艺，CDI具有潜在的竞争优势。拟议的CDI系统可用于市政设施或第三世界社区，为急需的人提供饮用水。本项目将培养1名博士和数名本科研究生。它将有助于更新实验室仪器，用于研究和教学。此外，该项目将以修改后的方式作为威斯康星大学每年秋季学期工程学本科入门课程的设备模板。在这堂课上，16名学生将组成一个工程团队，与无国界工程师组织（EWB）合作开发一个太阳能CDI系统，EWB将在肯尼亚进行实地测试。

0852780AndersonCapacitive deionization (CDI) is a process that operates by sequestering ions in the electrical double layer near charged surfaces. Essentially, a solution of ions flows through a highly porous conducting pair of electrodes and anions or other negatively charged species are removed at the positive electrode while cations or positively charged species are separated from solution at the negative electrode. During the removal process, energy is being stored in a capacitive fashion and is readily available to lower the cost of energy consumption. In a recharge cycle, a reverse bias is applied forcing the electrochemically-sequestered ions to be released as brine, much as in both RO and evaporative distillation processes. Brine production is generally considered to be less for CDI than in RO operations. This proposal includes fundamental as well as practical studies of the CDI process using a novel asymmetric set of electrodes coated with nanoporous oxides. This research will utilize electrochemical impedance measurements and models tied to real-world pore size and pore size distributions to interpret our results. In addition, an insitu electrochemical FTIR system is to be developed to study molecular behavior inside these nanoporous oxide electrodes. From a practical perspective, many pairs of CDI electrodes must work in tandem, controlled electronically, and matched to water composition and flux for optimal ion removal. In this part of the proposed studies, a stack of electrodes will be assembled into a module and benchmarked with respect to ion removal versus time, electrode surface area, and energy cost per gallon of water processed. This portion of the proposed work will be completed in four parts: 1. Choosing an optimal supporting material for our electrodes 2. Coating this support with our best nanoporous oxide films. 3. Testing electrodes in four pair stacks and finally 4. Building a CDI prototype. Potentially, CDI can compete favorably as a desalination process. The CDI system proposed could be used by municipal facilities or in third-world communities providing potable water to people in severe need. This project will result in the training of one PhD and several undergraduate research students. It will contribute to renewed laboratory instrumentation to be employed in both research and teaching. In addition, this project will be used in a modified fashion as a device template for an undergraduate introductory course in engineering taught at the University of Wisconsin each fall semester. In this class, 16 students, forming an engineering team will cooperate with Engineers Without Borders (EWB), to develop a solar-powered CDI system that EWB will field-test in Kenya.