Prof. Liming Dai
Departments of Macromolecular Science and Engineering, Case Western Reserve Unversity, USA
Abstract: It is estimated that the world will need to double its energy supply by 2050. With the rapid increase in the global energy consumption, there is a pressing need for clean and renewable energy alternatives. Polymers have been traditionally used as electrically insulating materials: after all, metal wires are coated in plastics to insulate them. Various conjugated macromolecules with alternating single and double bonds can now be synthesized with unusual electrical and optical properties through the -electron delocalization along their 1D backbones. Due to the molecular rigidity of conjugated backbones, however, most unfunctionalized conjugated polymers are intractable (i.e., insoluble and/or infusible). Nevertheless, a number of synthetic methods have been devised to produce conjugated polymers with the processing advantages of plastics and the optoelectronic properties of inorganic semiconductors for optoelectronic device applications, including polymer photovoltaic cells.
Having conjugated all-carbon structures, carbon nanomaterials, including 1D carbon nanotubes (CNTs) and 2D graphene, also possess certain similar optoelectronic characteristics as conjugated macromolecules, apart from their unique structures and associated properties (e.g., surface/size effects). With the rapid development in nanoscience and nanotechnology, graphitic carbon nanomaterials (e.g., 1D CNTs, 2D graphene) have been playing a more and more important role in the development of efficient energy conversion and storage devices, including solar cells, fuel cells, supercapacitors and batteries. The combination of the unique physicochemical properties of graphitic carbon nanomaterials with comparable optoelectronic properties of appropriate conjugated macromolecules has yielded some interesting synergetic effects. Therefore, considerable efforts have recently been made to utilize graphitic carbon nanomaterials, along with polymers, as energy materials, and tremendous progress has been achieved in developing high-performance energy conversion and storage devices based on graphitic carbon nanomaterials and conjugated polymers. More recently, some 2D conjugated polymers and certain 3D graphitic carbon architectures (e.g., CNT-graphene pillared networks, graphene foams) have been demonstrated to show additional advantages for efficient energy conversion and storage.
In this talk, I will summarize our work on rational design and development of multi-dimensional conjugated polymers and graphitic carbon nanomaterials for efficient energy conversion and storage, including polymer solar cells containing graphitic carbon nanomaterials for improved charge transport, fuel cells and metal-air batteries with carbon nanomaterials/polymers as metal-free catalysts for oxygen reduction and evolution, and flexible supercapacitors based on CNT-/graphene-based electrodes for energy storage. A brief overview of this exciting field, along with some challenges and opportunities, will also be presented.
Venue: Conference Room of Basic Energy Science Building
Time: Sep. 7, 2015 (Monday) 9:30am