ZHUMABAY BAKENOV

Abstract:

Three-dimensional (3D) configuration of battery provides a large active surface area of the electrodes to store and utilize more active material, enabling a remarkable increase of capacity. This work reports a perfect conformal coating of a unique 3D structured NiO/Ni anode synthesized by a simple thermal oxidation process with PAA-PVA polymer multi-layers. The coating of the 3D structure with a polymer was carried out by electrophoretic deposition (EPD). EPD is an attractive colloidal method for the obtaining polymer and composite films. The EPD mechanism includes the electrophoretic movement of charged polymer molecules and the formation of a film on the electrode surface under the influence of an electric field. An aqueous solution of 2 wt% polyvinyl alcohol (PVA) was prepared by dissolving PVA in deionized water with vigorous stirring at 80 °C for several hours until the mixture turned into a homogeneous viscous solution. After cooling, isopropyl alcohol was added into the solution to suppress water decomposition in the EPD process. Then, 0.2 wt% SiO2 powder was added to the solution, which was subjected to 10 minutes of magnetic stirring followed by 20 minutes of sonication. A 2 wt% aqueous-alcoholic solution of polyacrylic acid (PAA) with 0.2 wt% LiCl was prepared similarly to the PVA solution. SEM and EDS-SEM analysis confirmed a uniform polymer deposition and distribution elements throughout the coating structure.