Researcher: Ying Wang
My research is focused on the development of high-rate Li-ion intercalation electrodes based on vanadium pentoxide (V2O5) for clean energy applications. We have prepared and studied the electrochemical properties of nanostructured or composite electrodes, including V2O5¡¤nH2O nanotube arrays, Ag-AgxV2O5¡¤nH2O composite films and Ni- V2O5¡¤nH2O core-shell nanocable arrays. Synthesis of these electrodes employs sol-gel processing, the template-based method, electrochemical deposition, and electrophoretic deposition. These intercalation electrodes have demonstrated higher energy density or power density in comparison with plain V2O5¡¤nH2O film electrode, due to the larger surface area, shorter diffusion distance and the enhanced electrical conductivity. Furthermore, capacity and cycling performance of V2O5¡¤nH2O have been investigated and optimized by manipulating water content in V2O5¡¤nH2O through thermal annealing.
For the future work, nanorod arrays of Cu-doped V2O5¡¤nH2O or copper vanadate are proposed in addition to the unique carbon-cryogel-vanadium-pentoxide nanocompoiste electrode. The former shows interesting phenomena such as reversible extrusion/insertion of copper ions during Li-ion intercalation/deintercalation processes. The latter is unique in the sense that the carbon-cryogel-vandium-pentoxide nanocomposite is characterized by three-dimensional energy storage and release processes, whereby conventional intercalation electrodes are two-dimensional systems. Obviously the energy that can stored in the three-dimensional structure is larger than in conventional electrode. The proposed electrodes are anticipated to show further improved electrochemical performance and give us a better fundamental understanding about relationships between processing, structure and properties.