Yifei He
Conjugated polymers (CP), a solution-processable and mass-producible semiconducting material, are a promising candidate in the application of organic solar cells. One important factor that determines the light-electricity conversion efficiency of CPs is the morphology. My research will thus primarily investigate the method to control the microstructure of the thin films via accurate copolymerization. The ultimate goal of my project is to establish the knowledge about the relationship of molecular structure-morphology-optoelectronic performances, which contributes to the future design of high performance polymers in solar cells that could be mass manufactured. Advisor: Christine Luscombe - Materials Science & Engineering...
Daniel Zhou
Thermoelectric materials, or materials that can convert waste heat into electricity are promising sources for renewable energy. For a thermoelectric material to be efficient, it must have low thermal conductivity and high electrical conductivity. Prime candidates for these materials are Zintl phases which are semiconductors that can exhibit metallic conductivity due to the contributions of ionic and covalent character. Both the cationic and anionic sites of these compounds can be manipulated to tune the electronic and thermal properties. The Velian group has developed redox-active nanoclusters that can be tuned electronically with the addition of different transition metals. I plan on linking these nanoclusters with inorganic...
Ying Xia
The focus of my research will be interface-assisted solution-synthesis of two-dimensional metal-porphyrin monoatomic layers (2D-PML), which are of great interest due to the tunability of their properties. I will use two methods to synthesize metal-porphyrin monoatomic layer structures, one is the hydrothermal method, the other is the water-oil interface assisted method. AFM will be the main characterization method to analyze nucleation and growth mechanisms during the synthesis procedure. Then clean energy applications such as catalysts for hydrogen evolution and electrical capacitance will be studied. Advisor: Jim De Yoreo and Jun Liu - Materials Science & Engineering...
Julia White
Advances in energy storage are a critical aspect of the effort to convert the world to clean energy sources as electrification increases. For applications such as electric vehicles, lithium ion batteries are the best technology available but need to be improved upon further to meet energy density and power demands. Anode-less lithium batteries are extremely promising for drastically increasing energy density and rate capabilities, yet dendrite formation leading to rapid failure remain an obstacle in their implementation. My research will focus on designing ultrathin (<50 micron) 3D current collectors, altering both geometry and chemistry, and examining the mechanism of lithium electrodeposition. The findings will...
Xiaoxiao Jia
Layered vanadium oxides have proven to be the most promising electrode materials for aqueous rechargeable batteries on account of their multiple valence states of vanadium and large interlayer spacing. However, capacity decay due to vanadium dissolution and structural instability remains a great challenge. Our prior research has revealed these problems can be mitigated by chemical pre-intercalation of metal cations with much enhanced power and energy densities as well as much improved energy conversion efficiency. But fundamental understandings are yet to be achieved, my next-step work includes a detailed study on effects of coordination, valences, electronegativity of those preinserted ions on the electronic and crystal...
Daphne Garcia
The focus of my research is to develop new electrode materials for energy storage devices by improving current chemical processes of dealloying brass sheets to create three-dimensional nanoporous copper structures. By controlling the dealloying process, a more even distribution of pores that are all less than a micron in diameter and greater surface area in the structure will be achieved. These structures will function as current collectors in lithium-ion batteries, with the potential for higher energy density, increased cyclic performance and rate kinetics. Variables such as dealloying chemical composition, brass composition, and sheet thickness will be analyzed to identify the ideal conditions for achieving...
Diwash Dhakal
Rechargeable batteries are among the candidates that can fulfill the evolving energy storage needs and are being researched extensively. My research focuses on the application of X-ray spectroscopy techniques to better understand the critical processes in rechargeable Zn-ion batteries (ZIBs). Specifically, I am looking at the local chemical environment and coordination complex in electrolytes and ion pairing in the electric double layer at electrode interfaces. Such a study will lead to a better understanding of the role of ion pairing on both structure and dynamics at the electrode-electrolyte-interface, a key question for ZIBs and many other battery systems. Advisors: Gerald T. Seidler, Guozhong Cao -...
Eleftheria Roumeli
Assistant Professor, Materials Science & Engineering The Roumeli group creates sustainable polymer nanocomposite materials from renewable resources, and specifically from plant and algae cells. We develop processing methods to transform the biomass to new biodegradable and multifunctional nanocomposites and study their structure-property relationships. Future applications for these materials and structures include critical material capturing and packaging. Email | Website | LinkedIn ...
Parker Steichen
My research focuses on the application of sulfide solid electrolytes in all solid state batteries (ASSB). While the high ionic conductivity of these materials have sparked significant interest amongst researchers, poor electrochemical stability has been a significant obstacle to realizing practical sulfide electrolyte based ASSBs. I am looking at how we can improve the long term stability of these materials so that we can realize practical and robust high energy density ASSBs. Advisor: Jihui Yang - Materials Science & Engineering...
Kaichen Xie
I plan to design and engineer novel two-dimensional quantum materials for future energy harvesting and conversion using computational and theoretical methods. I will continue current research on Janus 2D atomic layers. This work is based on our earlier computational discovery of a unique synthesis route of Janus transition metal dichalcogenides, which enables controlled growth and precise patterning of such Janus structures. In addition, our preliminary study shows strong light absorption and the intrinsic out-of-plane electric polarization of the Janus transition metal dichalcogenides. Based on this knowledge, I plan to explore new photovoltaic applications of these Janus systems, because photoelectrons and photoholes may spontaneously separate...
Emerson Chen
I will focus on organic mixed ionic-electronic conductors (OMIECs), which are often soft polymers or polymer blends with conjugated structure. They are promising candidates for supercapacitor and battery electrodes as they have great ionic-electronic coupling property and decent capability of ion and electron transportation. Also, the fabrication could be easily scaled up using roll-to-roll printing as most OMIECs are solution processable. In specific, I will synthesize PEDOT or Polythiophene with carboxybetaine/sulfobetaine zwitterionic side chains via chemical polymerization. EIS and OECT will be applied to characterize the synthesized materials for capacitance and kinetics studies. Higher specific capacitance and charging rate are expected as the zwitterion...
Amy Mayhugh
My research addresses ecological and economic factors that limit conjugated materials synthesis for solar energy. Conjugated polymers have the potential for widespread use in solar cells, as they can be cheap to produce, and installed in unique settings. Currently, synthesizing high-performing semiconducting polymers is energy intensive and complex. I study ways to reduce the number of synthetic steps while simultaneously prioritizing mild reaction conditions. I will continue my work on direct arylation polymerization (DArP) at room temperature for conjugated polymer synthesis. DArP is attractive as it directly functionalizes C-H bonds, avoiding the use of toxic organometallic intermediates. Due to the high selectivity and reactivity requirements for...