Electrode Details and Fabrication

The study of metal ion/metal(s) interfaces has been limited because of the excessive adsorption of the reactants and impurities at the electrode surface and due to the inseparability of the faradaic and nonfaradaic impedances. For obtaining reproducible results with solid electrodes, the important factors to be considered are the fabrication, the smoothness of the surface (by polishing), and the pretreatment of the electrodes, the treatment of the solution with activated charcoal, the use of an inert atmosphere, and the constancy of the equilibrium potential for the duration of the experiment. It is appropriate to deal with some of these details from a practical point of view. 

Very little work (relative to research of electrode materials and electrolytes) is directed toward characterizing and developing new separators. Similarly, not much attention has been given to separators in publications reviewing batteries.A number of reviews on the on cell fabrication, their performance, and application in real life have appeared in recent years, but none have discussed separators in detail. Recently a few reviews have been published in both English and Japanese which discuss different types of separators for various batteries. A detailed review of lead-acid and lithium-ion (li-ion) battery separators was published by Boehnstedt and Spot-nitz, respectively, in the Handbook of Battery Materials. Earlier Kinoshita et al. had done a survey of different types of membranes/separators used in different electrochemical systems, including batteries."... 

It is likely that we will see increasingly numerous examples of such systems in applications as diverse as home clinical chemistry assay kits and remote sampling for environmental applications. The discussion here outlines general applications and some of the unique physical properties and fabrication considerations of film electrodes, and then focuses in greater detail on preparation and properties of widely used examples of metallic, carbon film, and semiconductor electrode materials. 

The small electrode size not only imposes fabrication challenges and hmits the feasibility of SC-SOFCs with coplanar microscale electrodes, it also limits detailed analyses of these cells. SC-SOFCs with coplanar microscale electrodes yield very low conversion of the reactant gases, so that differences between input and output gases cannot be easily detected by mass spectrometry and information about the reactions that occur cannot be obtained. Similarly, the small electrode size makes impedance analysis difficult. The lack of fundamental studies and appropriate characterization and fabrication techniques leaves the working principles of SC-SOFCs with coplanar electrodes to a great extent unexplored. 

In the first part of this section of starting experiments with IPMC actuator, basics of ionic polymer used for IPMC, electroplating method, and fabrication of IPMC device including deforming ionic polymer and patterning electrode are described. Since details of ionic polymers and plating methods are described in the preceding chapters, this part describes only a summary of them. 

These apparent discrepancies (from no degradation to measurable and significant performance loss with each cycle) in the various literature results can perhaps be attributed to differences in the experimental protocol and in the details of the cell assembly. In particnlar, one expects that differences in membrane electrode assembly (MEA) fabrication technique can have considerable impact on the location of where water collects in the cold state, and on the relative strength of adhesion between adjacent layers. 

The SECM can also be used as a tool for modification of surfaces. For example, metals or semiconductors can be etched or metals can be deposited on a surface by passing the tip close to the surface and carrying out an appropriate electrochemical reaction. Two different modes are possible. In the direct mode, the tip acts as the counter electrode and the desired electrochemical reaction occurs on the substrate for example, the etching of Cu occurs on the Cu substrate. Spatial resolution is determined by the current density distribution between tip and substrate. In the feedback mode, a reactant is generated at the tip that promotes the reaction on the substrate. For example, Cu can be etched by bromine electrogenerated at the tip. In this case, resolution is determined by the lateral (x-y) diffusion of reactant as it diffuses from tip to substrate. Details of fabrication using SECM are covered in Chapter 15. 

The fabrication of memristor device has been divided into three steps which includes, (1) Cleaning of bottom substrate, (2) preparation of active layer of ZnO, and (3) preparation of Ag top electrode. Detailed description of each step is given below ... 

---