Hybrid Carbon-Bismuth Nanoparticle Electrodes

for Energy Storage Applications

Trevor Yates, Junior, University of CincinnatiAdam McNeeley, Pre-Junior, University of Cincinnati William Barrett, Sophomore, University of Cincinnati

GRA: Abhinandh SankarAC: Dr. Anastasios Angelopoulos

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Why is renewable energy important?

1. 86.4% of the world’s energy supply is based around fossil fuels2. At least millions of years for dead organisms to decompose and transform3. Energy demand doubles every 14 years

“By the year 2020, world energy consumption is projected to increase an additional 207 quadrillion (2.07 x 1017) BTUs. If the global consumption of renewable energy sources remains constant, the world’s available fossil fuel reserves will be consumed within 104 years.”- US Department of Energy, 2010

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PurposeCarbon-Bismuth Studies

Vanadium Studies

Vanadium RedoxFlow

Batteries

http://img.wallpaperstock.net:81/windmills-wallpapers_22092_1600x1200.jpg

http://www.messib.eu/assets/images/VRB_1_general_layout_VRFB.jpg

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http://www.digsdigs.com/photos/fiedler-house-christmas-lights-1.jpg

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Cost Analysis: 1 KW UnitVanadium 1.5 M VOSO4 and 10 M H2SO4 electrolyte costs

$1.60/kgStorage Tanks 153 Liters of electrolyte required to generate 1 kW

Pumps 0.0866 L/min flow required with 0.5 m head pressure

Electrodes Volume based on required current and current density

Membrane Same SA as electrode and Nafion 117 costs $100/ft2

Total: $64 (153 L electrolyte) + $500 (4 x 50 L Tanks) + $110 (1 hp pump) + $40 (2 electrodes) + $2,634 (26.34 ft2 membrane) = $3,348

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Introduction Basic Electrochemistry Vanadium Redox Flow Batteries Cyclic Voltammetry Application Methods Research Parameters Results and Interpretations Future Studies

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Electrochemistry

The study of the flow of electrons in chemical reactions Redox Reactions Anode and Cathode Reaction Potentials

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http://www.messib.eu/assets/images/VRB_1_general_layout_VRFB.jpg

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Cyclic Voltammetry

Voltage Sweep Between two set values

Current Peaks Scan Rates

Determined by user

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Layer by Layer Standard Directed

Bismuth

Tin (Sn)

Polymer

Carbon

Polymer

Bismuth

Tin (Sn)

Carbon

Polymer

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What we Have Learned...

Polymer important for LbL NaOH wash helpful Particles deteriorate

Glovebox Carbon Stabilizes Bismuth sLbL is better than dLbL 4Bi + 3O2 2Bi2O3

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Carbon

No Carbon

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sLbL

dLbL

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Vanadium Studies

Negative electrodeV3+/V2+

Reduction reaction happens near H+ reduction

Electrocatalyst

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Bismuth as an Electrocatalyst

Makes it easier for electrochemical reaction to happenTerms of Cyclic Voltammetry

Shifts peak currents closer togetherIncreases peak current heights

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-1 -0.8 -0.6 -0.4 -0.2

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-6

-4

-2

0

2

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Potential (V vs Ag/AgCl)

Cur

rent

Den

sity

(mA

/cm

2 )

Bismuth Improves Performance of Negative Electrode

8-Layers/Carbon4-Layers/Carbon-Bismuth8-Layers/Carbon-Bismuth

4/Carbon-Bismuth

8/Carbon-Bismuth8/Carbon

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Ipc and Ipa

Ipc

Cathodic peak current Bottom peak

Ipa

Anodic peak currentTop peak

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How to Calculate Ipc and Ipa

Have to extrapolate line Finding a “baseline”

Why?Glassy Carbon produces current

This is considered zero

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-1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0-0.01

-0.005

0

0.005

0.0140mV/s 8 Layer Carbon Control sLbL (Example)

Cur

rent

Den

sity

(mA

/cm

2 )

Potential (V vs. Ag/AgCl)

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Ipc and Ipa ResultsTest

ElectrodeIpc

(mA/cm2)Ipa

(mA/cm2)Epc (V) Epa (V) Abs

(Ipa/Ipc)ΔE (V)

Carbon Control

-0.00466 0.000759 -0.9618 -0.394 0.162855 0.5678

4 Layer Hybrid

-0.00364 0.001369 -0.9799 -0.4201 0.375996 0.5598

8 Layer Hybrid

-0.00418 0.001861 -0.8617 -0.4759 0.445386 0.3858

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Interpretations

Carbon has little effect on reaction Bismuth improves reversibility and peak currentIncreasing amount also improves reversibility and peak current

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Future StudiesWhy Carbon stabilizes Bismuth peaksScanning electron microscope

Characterize what’s occurringScale up productionQuantify improvement on VRFB performance

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Timeline23

Thank You NSF!

Grant ID No. 0756921EEC: 1004623

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References1. http://www.energy.gov/science-innovation/energy-sources

2. http://www.ecology.com/2011/09/06/fossil-fuels-renewable-energy-resources/

3. http://www.messib.eu/assets/images/VRB_1_general_layout_VRFB.jpg

4. http://www.digsdigs.com/photos/fiedler-house-christmas-lights-1.jpg

5. http://img.wallpaperstock.net:81/windmills-wallpapers_22092_1600x1200.jpg

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References Continued

• 6. Zhenguo Yang, Jianlu Zhang, et al. “Electrochemical Energy Storage for Green Grid” Chemical    Reviews, 2010 Pacific Northwest National Laboratory, Richland, Washington 99352, United States.

• 7. Dennis H. Evans, Kathleen M. O’Connell, et al. “Cyclic Voltammetry” Journal of Chemical Education, 1983 University of Wisconsin-Madison, Madison, WI 53706.

• 8. David J. Suarez, Zoraida Gonzalez, et al. “Graphite Felt Modified with Bismuth Nanoparticles as Negative Electrode in a Vanadium Redox Flow Battery” CHEMSUSCHEM, 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

• 9. Gareth Kear, Akeel A. Shah, and Frank C. Walsh. “Development of the all-vanadium redox flow battery for energy storage: a review of technological, financial and policy aspects” International Journal of Energy Research, 2012 Electrochemical Engineering Laboratory, Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.

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Questions?27