2013-14 BERN Research grants were awarded for the following projects:
♦ Professor Jeffrey Long, University of California at Berkeley: Metal-Organic Frameworks as Low-Cost and Sustainable Battery Components.
Metal-organic frameworks (MOFs) are a new class of microporous, three-dimensional materials built up from metal ion nodes linked by multitopic organic ligands. Although the properties of these materials can be tuned to suit a wide range of applications through judicious selection of metal ions and bridging ligands, their adaptation for electrochemical energy storage remains largely unexplored. Recently some of these materials have demonstrated remarkably high ionic conductivities for both lithium and magnesium ions. The applicability of metal-organic frameworks as solid electrolytes in lithium, sodium and magnesium batteries will be explored. Sold MOF electrolytes would eliminate volatile or flammable solvents and prevent internal shorting by suppressing metal dendrite formation, which is a major concern during rapid charging in lithium batteries. If successful, this approach will lead to improvements in operational safety, as well as gains in battery performance without a significant increase in manufacturing cost.
♦ Professor G. Jeffrey Snyder, California Institute of Technology: Earth-abundant Thermoelectrics for Waste Heat Recovery.
Thermoelectrics are made from earth abundant materials and with high figure of merit zT greater than 1 are required for waste heat recovr with global impact. While recent breakthroughs at Caltech have helped achieve this goal in PbTe alloys, the use of earth abundant materials are desirable for wide-scale applications. Fortunately, the Band STructure Engineering approach to Iv-VI thermoelectric semiconductors such as PbTe can be extended to other semiconductors to engineer their electronic structure.
♦ Professors William Goddard, Michael Ortiz and Julia Greer at California Institute of Technology: Reversible Metal-Air Batteries: In Silico Based Design Combined with Experimental Synthesis and Characterization.
This project uses the validated first-principles based hierarchical multiscale approach to carry out in silico materials and process design for Li-air secondary batteries, focusing on materials, properties and dynamics of electrodes, electrolyte, and interfaces. Four critical problems will be addressed: 1) Dendrite formation and electrolyte compatibility on the negative Li-metal electrode side; 2) Chemical reactions and Li-transport through the different components of the system, including corresponding interfaces; 3) Li2O and Li2O2 formation and dissociation on the positive electrode side; and 4) Demonstration of the feasibility of hollow Au nano-trusses to serve as positive electrode in Li/air (oxygen) batteries. Quantum mechanics calculations will be used to describe interactions between components of the system, determine energy barriers for chemical reactions and diffusion, and describe stability of the system components and reversibility of chemical reaction products upon charge and discharge processes.
♦ Professor Huei Peng, University of Michigan. Optimal Configuration, Component Sizing and Control of a Power-Split System for Hybrid Passenger Cars and Trucks.
This project we seek to develop a systematic procedure to design and analyze power-split hybrid powertrain for fuel economy and beyond. Our approach includes exhaustive searches through all possible configurations of power-split powertrains that use two planetary gears (PGs), with clutches added to establish multiple operating modes; and automated modeling, including all possible modes (1DOF, 2DOF, 3DOF with single or double outputs).
♦ Professor Yang Shao-Horn at Massachusetts Institute of Technology: Chemical Stabilization of Cathodes for Rechargeable Li-O2 batteries.
Li-O2 batteries hold the promise of 2-4 fold higher gravimetric energy density than current Li-ion systems. Current Li-O2 batteries are limited to carbon-based cathodes, which have been shown to be chemically unstable during battery discharge and charge. This project explores how using non-carbon surfaces could improve battery stability and provide new insight into nucleation and growth mechanisms upon discharge.
♦ Professor Gianluca Iaccarino, Stanford University: Wall-impinging Lotus Fins.
Lotus-type fins consist of porous plates where straight pores are formed by precipitation of supersaturated gas dissolved in the melted solid material, usually copper, during solidification. Lotus fins have been found capable of increasing the heat transfer capacity while minimizing the pressure losses through the micro-channels when compared to other porous materials such as sintered porous metals, cellular metal and fibrous composites. Numerical simulations and experimental work carried out at the Center for Turbulence Research at Stanford confirm the significant increase of the heat transfer capacity via the Colburn factor by direct comparison with traditional louvered fins and porous fins when high-porosity Lotus fins are employed.