美国加州大学Cengiz S. Ozkan教授报告

报告题目： Design of Materials for Advanced Energy Storage

报告人：Cengiz S. Ozkan教授

报告时间：2018年11月15日 14:00

报告地点：电院群楼3-101

欢迎大家踊跃参加 !

Cengiz S. Ozkan

Professor of Mechanical Engineering and Materials Science and Engineering

John J. Guarrera Engineering Educator of the Year

DARPA STARNet Center for Spintronic Materials and Novel Architectures

University of California Riverside, CA, 92521 USA

Design of Materials for Advanced Energy Storage

Graphene – CNT – Ruthenium Oxide  Hybrid Architecture for Supercapacitors (a-b) Schematic illustration of the preparation process for RGM architectures. SEM images of (c) as-grown GM foam          (d) lightly loaded RGM, and (e) heavily loaded RGM.

Abstract

The global electrochemical energy storage market ranging from electric vehicles and personal electronics to physical grid storage and defense applications demands the development of new classes of materials for fabricating high performance batteries and supercapacitors. I will describe innovative approaches for the design and synthesis of nanostructured materials towards enhanced reversible capacity; superior rate performance and cycling stability; superior gravimetric capacitance; and enhanced energy density and power density. Hierarchical three dimensional (3D) graphene-nanotube hybrid materials called pillared graphene nanostructures (PGN) grown by chemical vapor deposition possess ultra large surface area, tunability, mechanical durability and high conductivity which are appealing to diverse energy storage systems. Integration of nanostructured pseudocapacitive metal oxides to such 3D hierarchical templates provides superior electrochemical performance. Among the high performance capacitor systems developed includes MGM (graphene-MWNT-Manganese oxide) and RGM (graphene-MWNT-Ruthenium oxide) hybrid systems. High specific/areal capacitance and extended operational voltage window provides an exceptionally high energy density and power density. Similar three-dimensional templates are transformed into cone-shaped carbon nanotube clusters decorated with amorphous silicon for lithium ion battery anodes (SCCC), by depositing amorphous silicon onto the mesoporous nano-carbon templates via magnetron sputtering. The seamless connection between silicon decorated CNT cones and the graphene substrate facilitates charge transfer and provides a binder-free technique for preparing lithium ion battery anodes. Lithium ion batteries based on the SCCC architecture demonstrated ultra-fast charging, high reversible capacity and excellent cycling stability. Mildly reduced GO (mrGO) and silica coated Sulfur particles (SCSP) have been developed as new generation cathode materials, forming the basis for Li–S batteries. During cycling, SCSPs fracture and release active material, and mrGO helps to contain the ruptured particles, thereby reducing the polysulfide shuttling effects and improving the cycling stability.

Brief Biography

Cengiz Ozkan is a Professor of Mechanical Engineering at the University of California, Riverside since 2009. He received his Ph.D. in Materials Science and Engineering from Stanford University in 1997. His areas of expertise include nanomaterials for energy storage; synthesis of 2D materials including graphene; novel battery and supercapacitor architectures; nanoelectronics; biochemical sensors; and nanopatterning for beyond CMOS. He organized and chaired over 35 scientific and international conferences, including the symposium titled “Interfaces in Advanced Electrochemical Energy Storage” at the MRS Fall 2017 Meeting in Boston. He is currently organizing the symposium titled “Battery Technologies for Next Generation Electric Vehicles and Grid Storage Applications”, for the Fall 2019 MRS Meeting in Boston, MA. He has more than 300 technical publications including journal papers, conference proceedings, abstracts and book chapters; over 80 patent disclosures, has given more than 140 presentations worldwide, and has 15 patents licensed by the industry. Dr. Ozkan participated in several televised interviews to talk about the progress and future of energy storage technologies, and his research received significant media attention with press releases published by a large number of news outlets, including The Wall Street Journal, Huffington Post, Fast Company, Fox News, Science Channel, Discovery News, CNET, MTV News, Physics Today, Materials Today, Popular Science, etc.