Batteries and fuel cell research Sri Narayan worked for 20 years at NASA s Jet Propulsion Laboratory (JPL) where he led the fuel cell research activities for over 15 years and also headed the Electrochemical Technologies Group for 7 years. While at JPL, Dr. Narayan and his associates pioneered the development of direct methanol fuel cell power sources for military and commercial applications, developed new approaches to catalyst preparation by the sputter-deposition technique, new membranes and stacks, and demonstrated a range of hybrid power source systems for space and defense application. He received NASA-JPL s Exceptional Achievement Award for the development of direct methanol fuel cell and transferring the technology to industry. He has over 35 journal publications and 40 US Patents on various aspects of electrochemical technology. He has delivered invited talks on numerous occasions and has organized several conferences under the auspices of the Electrochemical Society. He is currently the Chairman of the Energy Technology Division of the Electrochemical Society of USA. He has active collaborations with various DoE National Laboratories and Industry. Prof. Narayan joined the faculty of the Department of Chemistry, Loker Hydrocarbon Research Institute in May 2010 to advance electrochemical power sources research. Surya Prakash joined the faculty of USC in 1981 and is the George A. and Judith A. Olah Nobel Laureate Chair in Hydrocarbon Chemistry at the Loker Hydrocarbon Research Institute and Department of Chemistry. He also serves as the Director of the Institute. His primary research interests are in superacid, hydrocarbon, synthetic organic and organofluorine chemistry, with particular emphasis in the areas of energy and catalysis. He is a co-inventor of the proton exchange membrane based direct oxidation methanol fuel cell and a co-proponent (with Professor Olah) of the Methanol Economy concept. Professor Prakash is a prolific author with more than 630 peer-reviewed scientific publications and holds 30 patents. He has also coauthored or edited 10 books. He has received many awards and accolades including two American Chemical Society National Awards: in 2004 for his achievements in the area of fluorine chemistry and in 2006 for his contributions to hydrocarbon chemistry. He also received the 2006 Richard C. Tolman Award from the Southern California section of the American Chemical Society for his scientific contributions to Southern California. He is the recipient of the 2007 Distinguished Alumni Award from his alma mater, Indian Institute of Technology, Madras and the 2010 CRSI Medal from the Chemical Research Society of India. He is a fellow of the American Association of Advancement of Science and a Member of the European Academy of Arts, Sciences and Humanities. He also sits on several Editorial Boards of Chemical Journals.
Batteries and Fuel Cell Research Sri Narayan and G. K. Surya Prakash Loker Hydrocarbon Research Institute University of Southern California Los Angeles, CA 90089-1661 The USC Power Research Workshop, November 18, 2011
Methanol, fuel and feed-stock: The Methanol Economy CH3OCH3, high cetane clean burning diesel fuel, LNG and LPG substitute. High octane (ON= 100) clean burning fuel, 15.8 MJ/liter. M-85 Fuel
Direct oxidation methanol fuel cell (DMFC) USC, JPL - Caltech e - e- e - - + Anodic Reaction: CH 3 OH + H 2 O Pt-Ru (50:50) CO 2 + 6 H + + 6 e - CH 3 OH + H 2 O H + H + O 2 / Air Cathodic Reaction: 3/2 O 2 + 6 H + + 6 e - Pt 3H 2 O E o = 0.006 V CO 2 + H 2 O Anode - H + H + + Cathode H 2 O Overall Reaction: CH 3 OH + 3/2 O 2 E o = 1.22 V CO 2 + H 2 O + electricity Pt-Ru catalyst layer Pt catalyst layer E cell = 1.214 V Proton Exchange membrane (Nafion -H) US Patent, 5,599,638, February 4, 1997; Eur. Patent 0755 576 B1, March 5, 2008.
Direct Methanol Fuel Cell Advantages!Methanol, 5 kwh/liter Theoretical (2 X Hydrogen)!Absence of Pollutants H 2 O and CO 2 are the only byproducts!direct reaction of methanol eliminates reforming Reduces stack and system complexity Silent, no moving parts!capable of start-up and operation at 20 C and below Thermally silent, good for military applications!liquid feed of reactants Effective heat removal and thermal management Liquid flow avoids polymer dry-out Convenient fuel storage and logistic fuel
Olah, G.A.; Goeppert, A.; Prakash, G.K.S. J. Org. Chem., 2009, 74, 487 Olah, G.A.; Prakash, G.K.S.; Goeppert, A. J. Am. Chem. Soc. 2011, 133, 12881 12898
CRI Carbon Recycling International George Olah CO 2 to Renewable Methanol Plant Groundbreaking HS Orka Svartsengi Geothermal Power Plant, Iceland, October 17 th 2009 Production capacity: 10 t/day, planned expansion to 100 t/day geothermal CO 2 + 3H 2 H 2 O US Patents 7,605,293 and 7,608,743 Int. Pat. Appl., WO2010011504 A2 January 28, 2010 CH 3 OH + H 2 O electrolysis using geothermal electricity
George Olah Renewable Methanol Plant Carbon Recycling International, Iceland
The Methanol Economy Anthropogenic Carbon Cycle
Electrochemical Energy Conversion and Storage Sri R Narayan Loker Hydrocarbon Research institute University of Southern California
Three Focus Areas in Electrochemical Energy Conversion and Storage 1. Storing large quantities of electrical energy 2. Conversion of organic fuels to electrical energy 3. Fuel and chemical production using electricity
Today s Wind and Solar Capacity : 45 GW of wind generation; 12 GW of solar PV : Some states want to reach 33% by 2020 3
Requirements for Large Scale Energy Storage System >80% round trip efficiency ( charge+ discharge) 5000 cycles ( Low maintenance) 10 15 years 1 to 8 hour charge/discharge rate Capital Cost per kwh < $100 /kwh ($ 200 Billion ) Energy Cost : Primary cost of energy/ (round trip efficiency * cycle life) for a 2.5 cents /kwh of premium Abundant raw materials; no geo political constraints Easily recyclable/ environmentally friendly 4
Cost and Durability are Challenges for Battery Technologies Battery System Features/Advantages Major Disadvantages Zinc Bromine Flow Battery Vanadium Flow Battery Lithium Ion Rechargeable Sodium Sulfur Regenerative Fuel Cells Moderate energy density (65 Wh/kg), 1250 cycles, Moderate efficiency (70%), fairly mature technology with large units demonstrated. 3000 cycles, Moderate to high roundtrip efficiency( 85%) fairly mature technology that has been scaled up to 1 MWh High energy density and high power density (100 200 Wh/kg), 1000 cycles, High round trip efficiency (90%). High Energy density (100 150Wh/kg), 1500 3000 cycles, Moderate to high round trip efficiency (80%). High Energy Density ( 400 600 Wh/kg), High Power Density, 2000 cycles Moderate to high cost ( > $150 $200 /kwh), Cycle life and efficiency needs to be improved. High cost(>$500/kwh), toxic materials, relatively rare materials are used Very high cost (>$1000/kWh),safety and abuse tolerance is low, cycle life needs to be improved. Moderate High Cost ($200 300/kWh), High Temperature operation (300 o 350 o C), requires thermal management systems. High cost (>$1000/kWh), Efficiency is low (50%), and cycle life needs 5 to be increased.
Cost, Sustainability and Toxicity of Battery Materials Material Cost, Reserves, Million Toxicity $/kg metric tons [1] Zinc 2.2 150 Moderate to high Lead 2.2 95 High. Vanadium 27 38 High Chromium 10 1.8 High Bromine 0.60 15,000 as NaBr High Iron 0.20 100,000 of iron None ore Oxygen Almost Free Unlimited None [1] USGS Minerals Data 6
Iron Air Battery has High Energy Density and the Iron Electrode is Robust Electrode Reactions (Discharge): (+) Electrode : ½O 2 + H 2 O +2e 2OH E o = +0.41 V ( ) Electrode: Fe + 2OH Fe (OH) 2 +2e E o = 0.877 V Cell reaction : Fe + ½O 2 + H 2 O Fe(OH) 2 Cell voltage : 1.1 V during discharge High energy density Theoretical specific energy, 764 Wh/kg; at 20% it is 150 Wh/kg Robust iron electrode 3000 cycles have been demonstrated at 80% depth of discharge Very tolerant to overcharge and over discharge 7
Challenges and Technical Approach Challenge Suppressing hydrogen evolution during charge and stand Efficiency improvement Utilizing any residual evolved hydrogen for energy generation Efficiency improvement Identifying active bi functional catalysts for air electrode Efficiency improvement Developing robust bi functional air electrode cycle life improvement Preventing carbonation of the electrolyte cycle life improvement CO 2 free air supply with advanced amine absorber bi-functional air electrode on durable nanostructured support (+) -- - - - -- -- - - - --- - - - - - - - --- - - - - -- - - - -- - --- --- - - - - - -- -- - --- - ---- - - - - - - - - - - --- - - - - - - - - - - - --- --- -- - - - -- -- - - - - - - - - - - - - - --- - - - - - - -- - - - -- -- - - - - - - - - - - - - - --- - - - - - - - - - - - --- --- (-) Electrolyte additives to suppress hydrogen evolution Composite electrode Designed for hydrogen utilization Electrode additives to suppress hydrogen evolution 8
Examples of Iron Electrodes Pressed Plate Iron Electrodes 9
Test Cell Assembly Top View of Cell Reference Electrode Hg/HgO Reference Electrode Iron Electrode Iron Electrode Nickel Electrode Nickel Electrodes Electrolyte: 30% KOH 10
Battery Testing Cells under test 16 channel Battery Cycling Equipment 11
High Charge Efficiency of Iron Electrode with Additives With Additive
Discharge Rate of Iron Electrode is improved by the Additives With sulfide additive No additives 13
Challenges and Technical Approach Challenge Changes in Electrode Morphology -Reduces utilization and limits operating life Suppress hydrogen evolution -Reduces efficiency Low ionic conductivity of membrane Reduces efficiency Concentrated Fe 2+ Electrolyte Additives to suppress hydrogen evolution Dilute Fe 2+ Fe 2+ Novel Design of Porous Electrode Cl Load ( ) (+) Fe Cl Cl Cl Cl Interpenetrating Anion Conducting Membrane Cl Fe 3+ Cl Fe 3+ Cl Fe 2+ Fe Fe 2+ Durability of anion exchange membrane -Limits life time
Iron Chloride Redox Flow Battery Cell Ferrous chloride Ferric Chloride/ Ferrous chloride
Three Focus Areas in Electrochemical Energy Conversion and Storage 1. Storing large quantities of electrical energy 2. Conversion of organic fuels to electrical energy 3. Fuel and chemical production using electricity
Direct Oxidation of Small Organic Molecules in Fuel Cells - LOAD + 6e - 6e - CO 2 <3% Methanol / water CO 2 3H 2 O + H + H + H 2 0, N 2, O 2 6H + H + H + H + H + FUEL 3% Methanol / water H 2 O + CH 3 OH H + H + H + H + H + H + 6H + + 3/2 O 2 OXIDANT Air (O 2 ) - Electrode (Anode) + Electrode (Cathode) PROTON EXCHANGE MEMBRANE (PEM) 7 Motivation : Enable the widespread commercialization of direct methanol fuel cells Inexpensive catalysts for electro oxidation of organic molecules to carbon dioxide fuel cells, energy harvesting from waste water, utilization of biomass waste streams.
How can we can bottle the energy of the sun as a liquid fuel? Artificial Photosynthesis Electrochemical Reduction of Carbon Dioxide to fuels sunlight sunlight Any source of electricity is useful Can be tailored to produce a single product Relatively easy to scale up Increase the electric current to increase rate; Add more modules or cells to scale up. Occurs at ambient temperatures and pressures Carbon dioxide Organic Chemicals Photovoltaic Array e - e - - + Membrane Electrode Assembly Water oxygen 18
Durable and Inexpensive Oxygen Electrode Catalysts for Electrolysis and Fuel Cells Motivation and Broader Impact Durable and Inexpensive Oxygen Electrodes are required for: Metal Air Rechargeable Batteries Li, Zn, Fe Replacing precious metals in Electrolysis of water / Fuel Cells Energy efficient chlorine production Durable electrodes for electro synthesis by oxidation and reduction of organics