Hybrid Carbon-Bismuth Nanoparticle Electrodes for Energy Storage Applications Trevor Yates, Junior, University of Cincinnati Adam McNeeley, Pre-Junior, University of Cincinnati William Barrett, Sophomore, University of Cincinnati GRA: Abhinandh Sankar AC: Dr. Anastasios Angelopoulos 1

Why is renewable energy important? % of the world’s energy supply is based around fossil fuels 2. At least millions of years for dead organisms to decompose and transform 3. Energy demand doubles every 14 years “By the year 2020, world energy consumption is projected to increase an additional 207 quadrillion (2.07 x ) 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,

Purpose Carbon-Bismuth Studies Vanadium Studies Vanadium Redox Flow Batteries /windmills- wallpapers_22092_1600x1200.j pg ages/VRB_1_general_layout_V RFB.jpg 3

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Cost Analysis: 1 KW Unit Vanadium1.5 M VOSO 4 and 10 M H 2 SO 4 electrolyte costs $1.60/kg Storage Tanks153 Liters of electrolyte required to generate 1 kW Pumps L/min flow required with 0.5 m head pressure ElectrodesVolume based on required current and current density MembraneSame SA as electrode and Nafion 117 costs $100/ft 2 Total: $64 (153 L electrolyte) + $500 (4 x 50 L Tanks) + $110 (1 hp pump) + $40 (2 electrodes) + $2,634 (26.34 ft 2 membrane) = $3,348 5

Introduction  Basic Electrochemistry  Vanadium Redox Flow Batteries  Cyclic Voltammetry  Application Methods  Research Parameters  Results and Interpretations  Future Studies 6

Electrochemistry  The study of the flow of electrons in chemical reactions  Redox Reactions  Anode and Cathode  Reaction Potentials 7

/images/VRB_1_general_lay out_VRFB.jpg 8

Cyclic Voltammetry  Voltage Sweep  Between two set values  Current Peaks  Scan Rates  Determined by user 9

Layer by Layer StandardDirected Bismuth Tin (Sn) Polymer Carbon Polymer Bismuth Tin (Sn) Carbon Polymer 10

What we Have Learned...  Polymer important for LbL  NaOH wash helpful  Particles deteriorate  Glovebox  Carbon Stabilizes Bismuth  sLbL is better than dLbL 4Bi + 3O 2 2Bi 2 O 3 11

Carbon No Carbon 12

sLbL dLbL 13

Vanadium Studies  Negative electrode  V 3+ /V 2+  Reduction reaction happens near H + reduction  Electrocatalyst 14

Bismuth as an Electrocatalyst  Makes it easier for electrochemical reaction to happen  Terms of Cyclic Voltammetry  Shifts peak currents closer together  Increases peak current heights 15

4/Carbon-Bismuth 8/Carbon-Bismuth 8/Carbon 16

I pc and I pa  I pc  Cathodic peak current  Bottom peak  I pa  Anodic peak current  Top peak 17

How to Calculate I pc and I pa  Have to extrapolate line  Finding a “baseline”  Why?  Glassy Carbon produces current  This is considered zero 18

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I pc and I pa Results Test Electrode I pc (mA/cm 2 ) I pa (mA/cm 2 ) E pc (V)E pa (V) Abs (I pa /I pc ) ΔE (V) Carbon Control Layer Hybrid Layer Hybrid

Interpretations  Carbon has little effect on reaction  Bismuth improves reversibility and peak current  Increasing amount also improves reversibility and peak current 21

Future Studies  Why Carbon stabilizes Bismuth peaks  Scanning electron microscope  Characterize what’s occurring  Scale up production  Quantify improvement on VRFB performance 22

Timeline 23

Thank You NSF! Grant ID No EEC:

References

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 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. 26

Questions? 27