Aiming to build high performance energy storage and conversion devices, our research group will try to explore the environmental friendly, mild, cost-effective and scalable chemical synthesis methods to manipulate the size, morphology and structure controllable synthesis of unique micro-/nano-structures for functional materials focusing on multi-component transition metal compounds and their complex hybrid nanostructures, as well as the transition metal compounds/nanocarbon hybrid structures. Through the macroscopic manipulation of the electronic, thermal, mechanic and chemical properties of the micro-/nano-structures, we will try to investigate the intrinsic structure-property relationship and to disclose the embedded mechanism, which can further fulfill the practical applications of these nanostructured functional materials as high performance electrodes/electrocatalysts on energy storage and conversion devices including rechargeable batteries, water electrolyzer and fuel cells.
Our current research interest can be described in three aspects as bellows:
1. Complex Transition Metal Oxide Nanostructure based Electrode Materials for Rechargeable Batteries.
Mixed transition metal oxides (Denoted as MTMO) could possess superior electrochemical performance compared with simple transition metal oxides benefitting from their intrinsic better electrical conductivity and synergistic effect of multi-valence stated metal ions. However, the systematical investigation of size/morphology/surface/interface/structure effect on the electrocatalytic performance has yet to be performed due to the lack of appropriate synthetic methods to achieve the controlled synthesis. Therefore, we will try to exploit environmentally benign, cost-effective and easily scalable synthesis methods to achieve the controllable synthesis of various MTMO nanostructures, including hollow spheres, micro-/nano-tubes, nanosheets, nanowires with common solvents such as water, ethanol, ethylene glycol, etc. and cheap precursors such as metal nitrate, metal acetate, metal chloride, etc. and under mild conditions. Through the systematic investigation, we will understand the controlled mechanism for different nanostructures, which allow the further investigation of the relationship between the structure and electrochemical properties and discloser of the hidden mechanism.
2. Designed Synthesis and Device Applications of High Performance Electrocatalysts based on Transition Metal Compound Nanostructures.
Recently, a class of transition metal non-oxides, i. e. phosphide, carbide and nitride (Denoted as TMP/C/N) has attracted tremendous interest because of their promising electrocatalytic activity and chemical stability in acidic and basic medium, which could be potential candidates as electrocatalysts for fuel cells and hydrogen production. However, there are still several challenging issues which severely hinder the development of these materials on practical applications, including unsatisfactory catalytic activity, poor catalytic stability and high cost of the synthetic methods. Therefore, we propose to explore low cost and effective methods to build TMP/C/N advanced nanostructures aiming to solve the challenging issues through constructing mixed TMP/C/N nanostructures, TMP/C/N-based hybrid structures and TMP/C/N-carbon composites nanostructures.
3. Novel Hybrid Nanostructures for Energy Storage and Conversion Applications.
The electrochemical performance enhancement achieved by simple nanostructure engineering, such as tuning the particle size, geometric shape and porosity, is still unsatisfactory in terms of cycling stability, rate capability and electrocatalytic activity for transition metal compounds based electrode/electrocatalyst materials. Recently, hybrid nanostructures by combining inorganic nanostructures and/or carbon-based species such as graphene/reduced graphene oxide (G/rGO), carbon nanotubes (CNTs), carbon nanofibers (CNFs) and so on, have attracted tremendous attention since superior electrochemical properties could be expected. It is generally believed that these hybrid nanostructures could simultaneously overcome the shortcomings of poor electrical conductivity and poor mechanical stability in simple nanostructures, which might hold great promise towards the practical application of transition metal compounds based electrodes/electrocatalysts in electrochemical energy storage and conversion devices. However, the synthetic methods to high quality hybrid nanostructures with well controlled microstructure, morphology, composition, and interfaces is still of great challenge, which is critical to manipulate the electronic structure and interface properties. Therefore, we propose to explore feasible strategies to construct high quality novel hybrid nanostructures based on transition metal compounds to push the limit of performance enhancement.