Berkeley Lab

Energy Analysis of Stationary Fuels Cells

The goal of the energy analysis effort is focused on stationary fuel cells including small to large applications and low- to high-temperature applications.  This work involves total cost of ownership (TCO) including life-cycle analysis (LCA) and design-for-manufacturing analysis (DFMA).  This effort is joint with UC Berkeley with advisement from Strategic Analysis and Ballard Power Systems.

The goals of the activity are as outlined below with a final deliverable of an integrated model (as shown in the flow chart) and subsequent analysis of the use of that model.

FCEADiagram

For more information contact Tom McKone or Max Wei

Advanced Diagnostics in Fuel Cells

Of particular interest is developing diagnostics for the various transport and material properties for fuel-cell components.  Such techniques allow for better understanding and providing phenomenological and parameters for the modeling activities.  Recent developments and capabilities include:

  1. Capillary pressure – saturation curves for fuel-cell diffusion media and catalyst layers
  2.  Effective gas-phase diffusivities of diffusion media as a function of saturation
  3. Droplet adhesion force measurements of fuel-cell gas-diffusion layers
  4. Thermal conductivity
  5. Freeze kinetics in fuel-cell materials
  6. Water uptake in fuel-cell membranes and catalyst-layer ionomer
  7. X-ray analysis of membrane and ionomer, including
    a. Grazing-incidence small-angle x-ray scattering (GISAXS) for ionomer thin films
    FC_GISAXS
    b. Small-angle x-ray scattering (SAXS) for membrane structure
    c. Wide-angle x-ray scattering (WAXS) for membrane crystallinity
  8. Computed x-ray tomography for membrane water content and liquid-water in gas-diffusion layers
  9. Conducting atomic force microscopy
  10. Material mechanical properties
  11. Traditional analytical techniques including electron microscopy, elemental analysis, etc.

For more information, contact Adam Weber.

Physics-based modeling of Fuel Cells

The modeling undertaken at Berkeley Lab is focused on understanding the operation of various fuel-cell components and cells with a focus on transport phenomena, describing the losses in the polarization curve, and examining durability.  Of particular interest are investigations into lower temperature operation where liquid water exists, which is typically below about 50C since above that phase-change-induced (PCI) flow removes water in the vapor phase.

PCI flow:PCIFlow-300x59

 

The physics in the models typically include

 FCModelComponents

 

Berkeley Lab models primarily include analytical and 1-D, 1+1D, and 2-D analyses, but also 3-D and 1+2-D are sometimes utilized.

Current modeling work includes:

  1. Cell performance
  2.  Durability and degradation changes including voltage loss breakdown
  3. Impacts of low-loaded catalyst layers
  4. Multiscale model of membrane water uptake including effects of membrane degradation and compression
  5. Membrane degradation mechanisms including pinhole growth
  6. Correlating membrane properties including developing an intrinsic figure of merit for membrane macroscopic water uptake as a function of nanoswelling changes incorporating both humidity and temperature (i.e., thermal history) effects
  7. Models for defect detection technologies and impact (in association with NREL)

For more information contact Adam Weber

BESTAR Staff win RD100 Awards

Gao Liu  and Mike Tucker from EETD win R& D 100 Awards

(Stories from the Berkeley Lab Newscenter)

Better Batteries with a Conducting Polymer Binder

conducting polymer binderIn an effort to make smaller, lighter, and cheaper batteries, a team led by Berkeley Lab scientist Gao Liu focused on improving the negative electrode, or anode. Their invention, the Conducting Polymer Binder, is a new material for use in rechargeable batteries. It can boost power storage capacity by 30 percent, a dramatic improvement in a field marked by little progress for more than a decade. The binder is literally a kind of flexible plastic glue that holds electrode materials together while facilitating the shuttling of electrons and positively charged lithium ions.

The new binder is unusually attractive for battery designers: it is strong, elastic, porous, and highly conductive. The elastic material stretches during the expansion of silicon particles as the battery charges, and contracts during discharge — giving silicon anodes the flexibility to “breathe.” The team used a soft X-ray beamline at the Advanced Light Source to analyze materials. Liu worked with Berkeley Lab scientists Wanli Yang, Lin-Wang Wang, and Vincent Battaglia and postdoctoral fellows Sang-Jae Park, Mingyan Wu, and Shidi Xun.

Cheap, Rugged Fuel Cells Can Provide Electricity Where None Exists

Point Source Power and Berkeley Lab won an R&D 100 award for the company’s Voto product. The innovative device is based on a solid oxide fuel cell that is powered by burning charcoal, wood or other types of biomass—even cow dung—the types of fuel that many in the developing world use for cooking. The fuel cell sits in the fire and is attached to circuitry in a handle that is charged as the fuel cell heats up to temperatures of 700 to 800 degrees Celsius. The handle, which contains an LED bulb, can then be detached and used for lighting or to charge a phone.

kibera_shoot-17Craig Jacobson, CEO and co-founder of Point Source Power, based in Alameda, California, co-invented the fuel cell in his 13 years as a materials scientist at Berkeley Lab. Working with Steve Visco, Mike Tucker and Lutgard DeJonghe, all still affiliated with the Lab, their breakthrough was in finding a way to replace most of the ceramics in the fuel cell with stainless steel, a far cheaper and more durable material.

Fuel Cell Work in BESTAR

Fuel cells may become the energy-delivery devices of the 21st century.  Although there are many types of fuel cells, polymer-electrolyte fuel cells are receiving the most attention for automotive and small stationary applications.  In a polymer-electrolyte fuel cell, a fuel (e.g., hydrogen) and oxidant (e.g., oxygen) are combined electrochemically to produce water, electricity, and some waste heat.  By reacting electrochemically, one can obtain efficiencies higher than those limited by thermal combustion, i.e., Carnot efficiency.  Some other advantageous versus engines include quiet operation, modular design, and relatively clean emissions depending on the source of hydrogen.  Fuel cell applications include transportation, commercial and residential stationary, materials handling, and even physiological.

FCDiagram

At Berkeley Lab, we utilize a core team of electrochemists, chemical engineers, mechanical engineers, theorists, material scientists, and organic chemists. leverage LBNL facilities and core competencies and collaborate extensively with labs, industry, and academia thru CalCharge to focus on

This work is coordinated by Adam Weber.