Transition Metal Oxides for Energy Storage

Transition metal oxides (TMOs) have been interesting active materials for energy storage and electrochemical catalysts due to their high electrical conductivity, chemical stability, and promising catalytic activity, in many cases comparable to noble metals. TMOs with controlled morphology can potentially used to enhance the performance of lithium-ion batteries (LIB). LiCoO₂ (LCO) remains the best cathode material for LIBs in many portable device applications due to its high energy density and high initial Coulombic efficiency. With high specific surface area and promising catalytic activity, CoO-derived alloys could have significant applications in electrocatalysis. The controlled magnetic properties of the materials allow easy recovery of dispersed catalyst particles, and could be the basis for developing other magnetic applications.

This research thrust, led by PhD candidate Zheng Fu, is focuses on synthesis of magnetic three-dimensional (3D) hierarchical dendritic cobalt oxide (CoO) via a convenient one-pot solution phase synthesis method. The one-pot synthesis method has potential as a low-cost, convenient, and scalable process, in which particle nucleation and growth is driven by slow heating rather than rapid mixing, which is notoriously difficult to scale. The flower-shaped CoO nanocrystals synthesized by Fu can further serve as templates and precursors for a variety of iron cobalt oxide (Fe-Co-O), manganese cobalt oxide (Mn-Co-O) and nickel cobalt oxide (Ni-Co-O) nanostructures with similar morphology and different magnetic behavior. The shape and sizes of these magnetic 3D metal oxides are controlled by synthesis parameters such as ligands, additives, temperature, heating rate, and reaction time. The saturation magnetization and coercivity can be varied by tuning the ratio of metals.

• Zheng Fu (PhD)
• Saranya Pillai (MS)
• Zhengxi Xuan (BS)
• Chaeeon Lee (BS)