Recent Research Seminars

Recent Research Seminars

We are pleased to present information related to recent research seminars in the MEE Seminar Series.

The designing of MoO2/MoS2 nanomaterials for next-generation LIBs

Dr. Shan Hu
Post-doc research associate, School of Engineering Technology, Purdue University

Abstract

The ever-increasing energy demand and environmental deterioration exert huge pressure on the global energy infrastructure. Renewable-energy technologies, such as lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), and solar cells, have made a significant progress. LIBs have been widely applied in consumer electronics, automotive market, and grid for their high energy/power density and durable cycle life. Currently, most lithium-ion battery electrode materials have the disadvantages of poor stability, weak safety, unreasonable cycle life, which is difficult to meet the requirements for the next-generation LIBs. It is highly desirable to develop new anode candidates with high energy density, long cycling life, as well as environmental friendliness. Transition-metal chalcogenides (TMCs) have attracted tremendous attention for its multitude of possible valence states, stoichiometric compositions, and crystal structure. Compared with their oxide counterparts, TMCs usually exhibit better electrical conductivity, and thermal and mechanical stability. However, TMC materials undergo serious volume changes during the cycling process, which results in poor cycle stability.

In this presentation, we will discuss our recent progress on designing the molybdenum oxide, sulfide and their lithium storage capability. First, we will show the optimum designed MoO2-RGO composites which result in an enhanced specific capacity and cycling stability compared to commercial MoO2. Next, we will introduce the synthesis of the flower-like carbon coated MoS2 via hydrothermal method and annealing treatment. The desired multilayered sheet structure improves high reversible capacity, good rate capability, and cyclic stability, making it a promising anode for high-performance LIBs. Last, we will introduce the controllable fabrication of MoS2nanocrystals embedded in mesoporous carbon nanofibers via electrospinning method. These mesoporous nanofibers demonstrate improved interfacial charge-transfer kinetics and a robust microstructure which result in a high reversible capacities and excellent cycling stability. Such micro-/nanoscale design and engineering strategies may also be used to explore other nanocomposites to boost their energy storage performance.

About the Speaker

Dr. Shan Hu is currently a post-doctoral research associate in School of Engineering Technology of Purdue University working with Prof. Jason Ostanek. She received her master and PhD degree in Wuhan University of Technology in 2016 and she worked as a joint PhD student in Prof. Guozhong Cao’s group of University of Washington from 2012 to 2014. Then she started postdoctoral researcher in Purdue University in the group of Prof. Gary Cheng from 2016 to 2018. She has extensive expertise in the nano energy materials and electrochemical energy storage system. In particular, she has developed high-performance ultra-thin MoS2nanosheets for advanced lithium ion batteries using a facile hydrothermal method. Her work has been published in Journal of Materials Chemistry A, Journal of Physics Chemistry C, Chemistry-A European Journal, Nanoscale etc. The paper entitled “Preparation of carbon coated MoS2 flower-like nanostructure with self-assembled nanosheets as high-performance lithium-ion battery anodes”, which was published on the Journal of Materials Chemistry A, has been cited 145 times since 2014. And she has published 13 articles with total citations over 400 which is showing a broad impact on the materials science and engineering community.