Formation of Micro and Nanostructured Nickel/Silica and Nickel/Metal Composites by Electrodeposition of Mesoporous Silica onto Nickel Foam

摘要

Extremely high surface area porous electrodes are of interest as current collectors for advanced batteries and as the basis for supercapacitors. For moderate to large scale storage applications a three-dimensional material is needed with porosity at multiple length scales. We are developing a combined bottom up/top down approach to creating such materials by using electrodeposition of mesoporous silica on nickel foam, a commercially available porous conductor widely used as the current collector in various batteries. Electrodeposition produces a conformal coating on the nickel foam. By controlling the electrodeposition time the morphology of the mesoporous silica can be varied from a thin film up to 500 nm thick to a loosely bound agglomeration of mesoporous silica particles capable of completely filling the 0.3-0.5 mm voids of the nickel foam. The internal diameter of the mesopores in the silica can be controlled in the range 2.5-4.8 nm by changing the chain length of the templating surfactant used. Gas adsorption shows surface areas of 400-1600 m~2/g of silica deposited, consistent with the assumed structure of the material.