DOCSLIB.ORG

Relating Catalysis Between Fuel Cell and Metal-Air Batteries

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Relating Catalysis Between Fuel Cell and Metal-Air Batteries Perspective Relating Catalysis between Fuel Cell and Metal-Air Batteries Matthew Li,1,2 Xuanxuan Bi,1 Rongyue Wang,3 Yingbo Li,4,6 Gaopeng Jiang,2 Liang Li,5 Cheng Zhong,6,* Zhongwei Chen,2,* and Jun Lu1,* With the ever-increasing demand for higher-performing energy-storage sys- Progress and Potential tems, electrocatalysis has become a major topic of interest in an attempt to Catalyst research for fuel cells has enhance the electrochemical performance of many electrochemical technolo- led to much advancement in gies. Discoveries pertaining to the oxygen reduction reaction catalyst helped humanity’s understanding of the enable the commercialization of fuel-cell-based electric vehicles. However, a underlying physics of the process, closely related technology, the metal-air battery, has yet to find commercial significantly enhancing the application. Much like the Li-ion battery, metal-air batteries can potentially uti- performance of the technologies. lize the electrical grid network for charging, bypassing the need for establishing In contrast, metal-air batteries a hydrogen infrastructure. Among the metal-air batteries, Li-air and Zn-air bat- such as Li-air and Zn-air batteries teries have drawn much interest in the past decade. Unfortunately, state-of-the remain to be solved. Although the art metal-air batteries still produce performances that are well below practical metal anode used in this these levels. In this brief perspective, we hope to bridge some of the ideas from systems does play a large role in fuel cell to that of metal-air batteries with the aim of inspiring new ideas and di- limiting their commercial success, rections for future research. catalysis also remains quite challenging. In this perspective, a INTRODUCTION discussion is provided on the similarities and differences Increasing the energy density of the battery system on board electric vehicles (EVs) between metal-air catalysts and has become a major topic of research interest throughout the electrocatalysis com- fuel cells for aqueous (alkaline/ munity.1–3 The development of catalysts that efficiently facilitate the oxygen reduc- acidic) and aprotic electrolytes. By tion reaction (ORR) allowed for great commercial advances in the field. Recent appli- attempting to bridge the cation of fuel cell technologies in EVs has led to the commercialization of a variety of discussion between the fields and fuel cell vehicles such as the Toyota Mirai.4 This EV boasts an attractive cruising providing our own opinion on the range of 500 km, cold start capability, and a significantly shorter refueling time subject, we hope that this of 3 min when compared with battery-based EVs.5 Unfortunately, the price remains perspective will present itself as a relatively high (7 million Japanese yen or 57,500 USD in 20144) due to the large starting point in emulating the impact of the Pt-based catalyst on the cost of the vehicle and the low production vol- success of catalysis in fuel cells in umes.6,7 While this might be within the purchasing power of some consumers (as a the metal-air systems. luxury vehicle), it will unlikely become widespread at this price point. Beyond the development of vehicle cost, a country- or even a city-wide hydrogen infrastructure is still far from realization and is considered a major hurdle against the widespread adoption of hydrogen fuel cells in the transportation sector. In contrast to fuel cell technologies, the closely related metal-air batteries (MABs) can be seen as a decent compromise between lithium-ion batteries (LIBs) and hydrogen fuel cell systems. Theoretically, MABs such as the Li-air battery (LAB) should have drastically higher energy densities when compared with a LIB. While cal- culations taking into account the volume of some non-active material have led to more modest volumetric energy density estimates (less than LiCoO2-based LIBs), the gravimetric energy density has beencalculatedtobetwicethatofLIBs.8 More- over, the electricity infrastructure needed to recharge MABs will likely be able 32 Matter 2, 32–49, January 8, 2020 ª 2019 Elsevier Inc. to bootstrap the already present and quickly growing EV charging infrastructure (be it charging stations or potential future battery-swapping stations9). Although this is perhaps one of the most important advantages of MABs, it will inevitably come at the cost of energy density when compared with the hydrogen fuel cell. It is, however, important to note that this range disadvantage has already been rather well toler- ated by current LIB-based EV consumers, indicating that the energy difference be- tween MABs and hydrogen fuel cells might not be a polarizing deciding factor. The difference in recharge/refuel time between MABs and fuel cells will likely decrease with more standardization among battery-pack designs, thus promoting battery-swapping stations.9 With many candidate MAB systems for EVs such as LABs and Zn-air batteries (ZABs) among other MAB systems still suffering from unre- solved technical challenges,10–14 the future applications of MABs remain unclear. Although the commercial application of fuel cells in EVs has already gained substan- tial progress in recent years, most MABs have remained in their conceptual/proto- type stages. The clear difference in maturity between the two systems suggests very different technical challenges. On the surface, the MABs appear to be quite similar to fuel cells and are sometimes referred to as semi-fuel cells.15,16 Like the hydrogen fuel cells, all MABs also require an external oxidizing agent (O2)thatis ideally accessed from the ambient air, separate from the inherent mass and volume of the MAB system. Although there are many technical challenges associated with using a metal anode,17,18 the seemingly similar cathode between these systems have subtle yet significant differences. Variations in the nature of the discharge reac- tion and product, such as the solid/poorly soluble and insulating Li2O2 formed dur- ing the discharge of LABs19 versus the liquid water produced in hydrogen fuel cells, have led to a great divergence in their research strategies. While some researchers have attempted to relate the different systems, it is difficult to foresee how they will intersect.20–22 If clear analogies can be drawn between these systems, new para- digms in research can be devised. Therefore, it is timely to compare and contrast the different meaning of catalyst between these technologies, proposing a situation whereby similar design concepts can be used. We will first elaborate on the differ- ences and similarities between ZAB, LAB, and fuel cell catalysis in aqueous media. 1Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 Cass Avenue, We will then compare these technologies in aprotic media and propose operational Lemont, IL 60439, USA conditions whereby more similarities can be found and leveraged. 2Department of Chemical Engineering, Waterloo Institute of Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, AQUEOUS SYSTEMS ON N2L 3G1, Canada 3 Acidic Media Applied Materials Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, IL 60439, Among all the contemporary technologies for electrocatalysis, the most commer- USA cially successful is the application in the acidic medium hydrogen fuel cell, more 4Materials Science Division, Argonne National commonly known as the proton exchange membrane (PEM) fuel cell. Although Laboratory, 9700 Cass Avenue, Lemont, IL 60439, USA acid medium is not preferable for MABs (due to corrosion of Zn), it is important to 5College of Physics, Optoelectronics and Energy, contrast the catalytic mechanism. In acidic electrolyte fuel cells, it is commonly Center for Energy Conversion Materials & Physics accepted that an adsorbed oxygen will reduce to an adsorbed OH* or OOH* before (CECMP), Soochow University, Suzhou 215006, P. 23 R. China further reduction to H2O. During this process, the breakage of the O–O bond is 6 typically the rate-limiting step that requires a catalyst. Only by lowering the overpo- Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education) tential associated with ORR can PEM fuel cells operate at sufficient energy effi- and Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science ciencies and power densities. The ORR begins with the adsorption of O2 molecules and Engineering, Tianjin University, Tianjin onto the catalytically active sites on the surface of platinum. The next step is the 300072, China weakening of the oxygen bond and reduction of the molecule by protons and elec- *Correspondence: trons forming an adsorbed OOH* followed by a series of steps and intermediates [email protected] (C.Z.), (O*, OH*), finally forming water.23 The overall process is presented in Figure 1A. [email protected] (Z.C.), [email protected] (J.L.) The reaction kinetics is largely controlled by the degree to which the intermediates https://doi.org/10.1016/j.matt.2019.10.007 Matter 2, 32–49, January 8, 2020 33 Figure 1. Properties of Oxygen Reduction Reaction (A) O2 is shown to reduce to H2O with the various reaction rate constants denoted with a numbered k. Reproduced with permission from MarkovicandRoss.23 Copyright 2002, Elsevier. (B) Volcano plot for ORR activity versus HO* adsorption energy for various catalysts. On the left axis, Pt a plot of activity enhancement relative to Pt at U = 0.9 V (RHE) versus DGHO* À DG HO*,andonthe right axis a plot of U required for all reaction steps to be negative in free energy versus DGHO* À Pt 24 DG HO* Reproduced with permission from Stephens et al. Copyright 2012, Royal Society of Chemistry. are adsorbed by the catalyst surface. One would want a catalyst surface with the optimal adsorption energy for every intermediate to achieve the best catalytic activ- ity. However, the binding energies of all the intermediates in ORR are governed by what is known as a linear scaling relation (LSR).24 LSR refers to the phenomenon whereby moving toward a stronger adsorption of OOH* (one intermediate) to facil- itate the dissociation of O2 molecule will actually result in a less favored subsequent reduction and desorption of OH* (another intermediate).
Load more

Recommended publications
  • A Review of Cathode and Anode Materials for Lithium-Ion Batteries
    A Review of Cathode and Anode Materials for Lithium-Ion Batteries Yemeserach Mekonnen Aditya Sundararajan Arif I. Sarwat IEEE Student Member IEEE Student Member IEEE Member Department of Electrical & Department of Electrical & Department of Electrical & Computer Engineering Computer Engineering Computer Engineering Florida International University Florida International University Florida International University Email: [email protected] Email: [email protected] Email: [email protected] Abstract—Lithium ion batteries are one of the most technologies such as plug-in HEVs. For greater application use, commercially sought after energy storages today. Their batteries are usually expensive and heavy. Li-ion and Li- based application widely spans from Electric Vehicle (EV) to portable batteries show promising advantages in creating smaller, devices. Their lightness and high energy density makes them lighter and cheaper battery storage for such high-end commercially viable. More research is being conducted to better applications [18]. As a result, these batteries are widely used in select the materials for the anode and cathode parts of Lithium (Li) ion cell. This paper presents a comprehensive review of the common consumer electronics and account for higher sale existing and potential developments in the materials used for the worldwide [2]. Lithium, as the most electropositive element making of the best cathodes, anodes and electrolytes for the Li- and the lightest metal, is a unique element for the design of ion batteries such that maximum efficiency can be tapped. higher density energy storage systems. The discovery of Observed challenges in selecting the right set of materials is also different inorganic compounds that react with alkali metals in a described in detail.
    [Show full text]
  • Coal As Value-Added for Lithium Battery Anodes
    Coal as Value-Added for Lithium Battery Anodes Project Review Award No. DE-FE0031879 November 6th 2020 1 Project Summary • Semplastics has begun development of a novel material based on our X-MAT® polymer-derived ceramic (PDC) technology for use as an anode material in lithium-ion batteries • The X-MAT anode material is a composite of chemically tailored silicon oxycarbide (SiOC) and domestically sourced coal powder, designed to be a drop- in replacement for graphite within lithium-ion batteries • Preliminary tests of this material have shown more than twice the reversible capacity of graphite anodes • Through this project, Semplastics proposes to complete development and begin commercialization of this material 2 Project Description and Objectives 3 What are X-MAT Coal-Core Composite Powders? • Raw coal powder mixed with our proprietary polymer derived ceramic (PDC)-forming resin to produce coal-core composite powder materials – Electrically conductive – Low cost – Coal is 1-5¢/lb – The raw coal will not be burned during materials processing, and the resulting powder composite will not burn – Easily manufactured compared to typical ceramics – no sintering needed – Capable of using a variety of coals including lignite, bituminous, and anthracite particles in an “as-is” state with our proprietary PDC technology 4 How is this different from other approaches? • Our PDCs can be tuned at the Atomic Level to contain varying amounts of silicon, oxygen and carbon • Uses a “green” low-energy method – does not involve high-energy processes including
    [Show full text]
  • Transformative Renewable Energy Storage Devices Based on Neutral Water Input
    Transformative Renewable Energy Storage Devices Based on Neutral Water Input EStStUdtEnergy Storage Systems Update ARPA-E GRIDS Kick-Off 4 November 2010 Team • Proton Energy Systems – DKthADr. Kathy Ayers, PI – Luke Dalton, System Lead – Chris Capuano, Stack Lead – Project Lead; Electrolysis Stack and System; Fuel Cell System • Penn State University – Prof. Mike Hickner – Prof. Chao-Yang Wang – Electrolysis and Fuel Cell Membrane Material; Fuel Cell Stack 2 Proton Energy Systems • Manufacturer of Proton Exchange Membrane (PEM) hydrogen generation products using electrolysis • Founded in 1996 • Headquarters in Wallingford, Connecticut. • ISO 9001:2008 registered • Over 1,200 systems operating in 60 different countries 3 Proton Capabilities and Applications PEM Cell Stacks Complete Systems Storage Solutions • Complete product development, manufacturing & testing • Containerization and hydrogen storage solutions • Integration of electrolysis into RFC systems • Turnkeyyp product installation • World-wide sales and service Power Plants HtTtiHeat Treating SiSemicon dtductors LbLabora tor ies Government 4 HOGEN® C Series 3 • Maximum Capacity: 30 Nm /h H2 (65 kg/day) (~200 kW input) • Commercial availability: Q1 2011 • 5X h y drogen ou tpu t with onl15Xthfly 1.5X the foo t pritint 5 Next Steps in Scale Up • 70 Nm3/h • 150 kg/day • 400 kW input 0.6 SQFT 3 Cell (1032 amps, 425 psi, 50oC) 2.30 2.25 2.20 2.15 2.10 2.05 2.00 1.95 Potential (V) ll 1.90 Cel 1.85 Cell 1 Cell 2 Cell 3 1.80 1.75 0 1000 2000 3000 4000 Run Time (hours) 6 Hydrogen Cost Progression
    [Show full text]
  • NASA Fuel Cell and Hydrogen Activities
    NASA Fuel Cell and Hydrogen Activities Presented by: Ian Jakupca Department of Energy Annual Merit Review 30 April 2019 1 Overview • National Aeronautic and Space Administration • Definitions • NASA Near Term Activities • Energy Storage and Power • Batteries • Fuel Cells • Regenerative Fuel Cells • Electrolysis • ISRU • Cryogenics • Review 2 National Aeronautics and Space Administration 3 Acknowledgements NASA has many development activities supported by a number of high quality people across the country. This list only includes the most significant contributors to the development of this presentation. Headquarters • Lee Mason, Space Technology Mission Directorate, Deputy Chief Engineer • Gerald (Jerry) Sanders, Lead for In-Situ Resource Utilization (ISRU) System Capability Leadership Team Jet Propulsion Laboratory • Erik Brandon, Ph.D, Electrochemical Technologies • Ratnakumar Bugga, Ph.D, Electrochemical Technologies Marshall Space Flight Center • Kevin Takada, Environmental Control Systems Kennedy Space Center • Erik Dirschka, PE, Propellant Management Glenn Research Center • William R. Bennett, Photovoltaic and Electrochemical Systems • Fred Elliott, Space Technology Project Office • Ryan Gilligan, Cryogenic and Fluid Systems • Wesley L. Johnson, Cryogenic and Fluid Systems • Lisa Kohout, Photovoltaic and Electrochemical Systems • Dianne Linne, ISRU Project Manager • Phillip J. Smith, Photovoltaic and Electrochemical Systems • Tim Smith, Chief, Space Technology Project Office 4 Electrochemical System Definitions Primary Power Energy Storage Commodity Generation Discharge Power Only Charge + Store + Discharge Chemical Conversion Description Description Description • Energy conversion system that • Stores excess energy for later use • Converts supplied chemical feedstock supplies electricity to customer system • Supplies power when baseline power into useful commodities • Operation limited by initial stored supply (e.g. PV) is no longer available • Requires external energy source (e.g.
    [Show full text]
  • Fuel Cell Performance and Degradation
    REVERSIBLE FUEL CELL PERFORMANCE AND DEGRADATION by Matthew Aaron Cornachione A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering MONTANA STATE UNIVERSITY Bozeman, Montana April, 2011 c Copyright by Matthew Aaron Cornachione 2011 All Rights Reserved ii APPROVAL of a thesis submitted by Matthew Aaron Cornachione This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, English usage, format, citations, bibli- ographic style, and consistency, and is ready for submission to the The Graduate School. Dr. Steven R. Shaw Approved for the Department of Electrical and Computer Engineering Dr. Robert C. Maher Approved for the The Graduate School Dr. Carl A. Fox iii STATEMENT OF PERMISSION TO USE In presenting this thesis in partial fulfullment of the requirements for a master's degree at Montana State University, I agree that the Library shall make it available to borrowers under rules of the Library. If I have indicated my intention to copyright this thesis by including a copyright notice page, copying is allowable only for scholarly purposes, consistent with \fair use" as prescribed in the U.S. Copyright Law. Requests for permission for extended quotation from or reproduction of this thesis in whole or in parts may be granted only by the copyright holder. Matthew Aaron Cornachione April, 2011 iv ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Steven Shaw, for granting me the oppor- tunity to work at Montana State University as a graduate research assistant and for providing assistance to many aspects of this work from circuit design to machining parts.
    [Show full text]
  • 1 a Switchable Ph-Differential Unitized Regenerative Fuel Cell with High
    A switchable pH-differential unitized regenerative fuel cell with high performance Xu Lu,a Jin Xuan,be Dennis Y.C. Leung,*a Haiyang Zou,a Jiantao Li,ac Hailiang Wang d and Huizhi Wang *b a Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong b Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK c SINOPEC Fushun Research Institute of Petroleum and Petrochemicals, Fushun, China d Department of Chemistry, Yale University, West Haven, CT, United States e State-Key Laboratory of Chemical Engineering, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China Correspondence and requests for materials should be addressed to D.Y.C.L. (email: [email protected]) or to H.Z.W. (email: [email protected]). 1 Abstract Regenerative fuel cells are a potential candidate for future energy storage, but their applications are limited by the high cost and poor round-trip efficiency. Here we present a switchable pH- differential unitized regenerative fuel cell capable of addressing both the obstacles. Relying on a membraneless laminar flow-based design, pH environments in the cell are optimized independently for different electrode reactions and are switchable together with the cell process to ensure always favorable thermodynamics for each electrode reaction. Benefiting from the thermodynamic advantages of the switchable pH-differential arrangement, the cell allows water electrolysis at a voltage of 0.57 V, and a fuel cell open circuit voltage of 1.89 V, rendering round-trip efficiencies up to 74%.
    [Show full text]
  • Lithium Batteries
    LITHIUM BATTERIES 1. Introduction Over the past 20 years, lithium battery technology has dramatically evolved, providing increasingly greater energy density, greater energy per volume, longer cycle life and improved reliability. Lithium is the lightest of all metals, has the greatest electrochemical potential and provides the largest specific energy per weight. Lithium batteries are now powering a wide range of electrical and electronical devices, including laptop computers, mobile phones, power tools, telecommunication systems and new generations of electric cars and vehicles. Next to advantages, new technologies often bring new challenges and risks. Reports on incidents with lithium batteries catching fire have made the public well aware of their flammability hazard and have triggered massive research on the mechanisms initiating such events and the ways to make operation, storage, transportation and recycling safer. This document covers some of the safety related issues of lithium batteries. 2. Types of Lithium Batteries 2.1 Cell or Battery? Although the word "battery" is a common term to describe an electrochemical storage system, international industry standards differentiate between a "cell" and a "battery". A cell is a single encased electrochemical unit (one positive and one negative electrode) with a voltage differential across its two terminals (Figure 1). Figure 1: Examples of cells A battery is two or more cells that are electrically connected together and fitted with devices such as a case, terminals, marking and protective devices that it needs to function properly (Figure 2). EHS-DOC-147 v.2 1 / 18 Figure 2: Examples of batteries However, in common usage, the terms "cell" and "battery" are used interchangeably.
    [Show full text]
  • Section 3.4 Fuel Cells
    2016 FUEL CELLS SECTION 3.4 Fuel Cells Fuel cells efficiently convert diverse fuels directly into electricity without combustion, and they are key elements of a broad portfolio for building a competitive, secure, and sustainable clean energy economy. They offer a broad range of benefits, including reduced greenhouse gas emissions; reduced oil consumption; expanded use of renewable power (through the use of hydrogen derived from renewable resources as a transportation fuel as well as for energy storage and transmission); highly efficient energy conversion; fuel flexibility (use of diverse, domestic fuels, including hydrogen, natural gas, biogas, and methanol); reduced air pollution, criteria pollutants, water use; and highly reliable grid support. Fuel cells also have numerous advantages that make them appealing for end users, including quiet operation, low maintenance needs, and high reliability. Because of their broad applicability and diverse uses, fuel cells can address critical challenges in all energy sectors: commercial, residential, industrial, and transportation. The fuel cell industry had revenues of approximately $2.2 billion in 2014, an increase of almost $1 billion over revenues in 2013.1 The largest markets for fuel cells today are in stationary power, portable power, auxiliary power units, backup power, and material handling equipment. Approximately 155,000 fuel cells were shipped worldwide in the four-year period from 2010 through 2013, accounting for 510–583 MW of fuel cell capacity.2 In 2014 alone, more than 50,000 fuel cells accounting for over 180 MW of capacity were shipped.1 In transportation applications, manufacturers have begun to commercialize fuel cell electric vehicles (FCEVs). Hyundai and Toyota have recently introduced their FCEVs in the marketplace, and Honda is set to launch its new FCEV in the market in 2016.
    [Show full text]
  • Iron Based Cathode Catalyst for Alkaline Fuel Cells Thesis Presented in Partial Fulfillment of the Requirements for Honors Resea
    Iron Based Cathode Catalyst for Alkaline Fuel Cells Thesis Presented in Partial Fulfillment of the Requirements for Honors Research Distinction at The Ohio State University By Christopher Bruening Undergraduate Program in Chemical Engineering The Ohio State University 2014 Thesis Committee: Dr. Umit Ozkan, Advisor Dr. Kurt Koelling Copyright by Christopher Bruening 2014 Abstract Alkaline fuel cells take advantage of the reaction between hydrogen and oxygen to produce water and an electrical current. During the reaction, a hydroxide ion passes through a membrane from the oxygen side cathode to the hydrogen side anode. Previous research had been conducted on synthesis and evaluation of iron based catalysts for PEM fuel cells by the Heterogeneous Catalysis Research Group at The Ohio State University. PEM fuel cells use a similar reaction between hydrogen and oxygen except a proton travels across the membrane from the hydrogen side to the oxygen side, so the reaction mechanism differs. This paper looks into those same iron based catalysts tested in an alkaline environment. The catalyst in particular is 1% iron in 1:1 Black Pearls 2000 : 1,10 phenanthroline. Those precursors are combined using a wet impregnation and then the result is ball milled. It then undergoes an argon pyrolysis at 1050oC and an ammonia pyrolysis at 950oC which are the final steps in the synthesis. The completed catalyst can then be washed in acid for 1 hour, 2 days, or 1 week to compare the effect of acid washing on different factors. The different catalysts are compared at each stage in the synthesis mainly by their onset potential, which is the voltage where it produces a current density of 0.1 mA/cm2.
    [Show full text]
  • Advanced Ionomers & Meas for Alkaline Membrane Fuel Cells
    Advanced Ionomers & MEAs for Alkaline Membrane Fuel Cells PI Bryan Pivovar National Renewable Energy Laboratory June 15, 2018 DOE Hydrogen and Fuel Cells Program 2018 Annual Merit Review and Peer Evaluation Meeting Project ID #FC147 This presentation does not contain any proprietary, confidential, or otherwise restricted information. Overview Timeline and Budget Barriers • Project start: October 2015 • Durability • Project end: March 2019 • Cost • % complete: ~ 70% • Performance • DOE Budget plan Partners – FY 2016 - 2018 $ 2,600k – Cost Share Percentage – 0% • LBNL – Adam Weber • ORNL/UTK – Tom Zawodzinski • Colorado School of Mines – Andy Herring • (in-kind) 3M – Mike Yandrasits NREL | 2 Relevance/Impact DOE (Preliminary) Milestones for AMFCs* • Q2, 2017: Develop anion-exchange membranes with an area specific resistance ≤ 0.1 ohm cm2, maintained for 500 hours during testing at 600 mA/cm2 at T >60 oC. • Q4, 2017: Demonstrate alkaline membrane fuel cell peak power performance > 600 mW/cm2 on 2 H2/O2 (maximum pressure of 1.5 atma) in MEA with a total loading of ≤ 0.125 mgPGM/cm . • Q2, 2019: Demonstrate alkaline membrane fuel cell initial performance of 0.6 V at 600 mA/cm2 on 2 H2/air (maximum pressure of 1.5 atma) in MEA a total loading of < 0.1 mgPGM/cm , and less than 10% voltage degradation over 2,000 hour hold test at 600 mA/cm2 at T>60 oC. Cell may be reconditioned during test to remove recoverable performance losses. • Q2, 2020: Develop non-PGM catalysts demonstrating alkaline membrane fuel cell peak power performance > 600 mW/cm2 under hydrogen/air (maximum pressure of 1.5 atma) in PGM-free MEA.
    [Show full text]
  • Role of Diffuse Layer in Acidic and Alkaline Fuel Cells
    Author's personal copy Electrochimica Acta 56 (2011) 4518–4525 Contents lists available at ScienceDirect Electrochimica Acta journal homepage: www.elsevier.com/locate/electacta Role of the diffuse layer in acidic and alkaline fuel cells Isaac Sprague, Prashanta Dutta ∗ School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA article info abstract Article history: A numerical model is developed to study electrolyte dependent kinetics in fuel cells. The model is based Received 17 December 2010 on the Poisson–Nernst–Planck (PNP) and generalized-Frumkin–Butler–Volmer (gFBV) equations, and is Received in revised form 13 February 2011 used to understand how the diffuse layer and ionic transport play a role in the performance difference Accepted 15 February 2011 between acidic and alkaline systems. The laminar flow fuel cell (LFFC) is used as the model fuel cell Available online 23 February 2011 architecture to allow for the appropriate comparison of equivalent acidic and alkaline systems. We study the overall cell performance and individual electrode polarizations of acidic and alkaline fuel cells for Keywords: both balanced and unbalanced electrode kinetics as well as in the presence of transport limitations. The Alkaline fuel cell Acidic electrolyte results predict cell behavior based on electrolyte composition that strongly correlates with observed Alkaline electrolyte experimental results from literature and provides insight into the fundamental cause of these results. Electric double layer Specifically, it is found that the working ion concentration at the reaction plane plays a significant role in Laminar flow fuel cell fuel cell performance including activation losses and the response to different kinetic rates at an individual electrode.
    [Show full text]
  • Development of Power Generation by Durect Ethanol Fuel Cell
    FUEL CELL SYSTEMS S. Basu New Delhi Department of Chemical Engineering Indian Institute of Technology Delhi INDIA e- Load Water 1. Fuel chamber 2. Oxidant chamber 1 4 2 3. Anode (Pt) 4. Electrolyte Fuel 3 5 Oxidant 5. Cathode (Pt/C) (H ) 2 O2/Air + - H2 2 H +2e (Anode) + - 2 H +1/2 O2 +2e H2O (Cathode) H2 + 1/2 O2 H2O (Overall) 9 Automobile 9 Efficient Power Generation 9 Distributed Power Gen. 9 Environmental Friendly 9 Portable Electronics Eqpt. Fuel Cell Families Phosphoric Acid Cathode Anode o H+ 220 C Solid Polymer Cathode Anode o o H+ 30 C- 80 C Alkaline Air Cathode - Anode Fuel 50 oC- 200 oC OH Molten Carbonates o Cathode = Anode 650 C CO3 Solid Oxides Cathode Anode o o O= 700 C – 1000 C Alkaline Fuel Cell ALKALINE FUEL CELL Alkaline electrolyte - - Anode H2 + 2OH Æ 2H2O + 2e - - Cathode 1/2O2 + H2O + 2e Æ 2OH Overall H2 + 1/2O2 Æ H2O + electrical Energy +heat Poisoning: - 2- CO2 +2OH (CO3) + H2O ¾ Depletion of KOH ¾ Poisoning of cathode surface with carbonates Myth ! 9Kordesch, K. et al., (1999), Intermittent Use of a Low-Cost Alkaline Fuel Cell-hybrid System for Electric Vehicles, J. Power Sources, Vol. 80, pp. 9McLean, G. F. et al. (2002) An assessment of alkaline fuel cell technology, Int. J. Hydrogen Energy 27 507 9Gülzow, E., and Schulze, M. (2003), Long-Term Operation of AFC Electrodes With CO2- Containing Gases, J. Power Sources, Polymer Electrolyte Membrane Fuel Cell (PEMFC) Hydrogen Fuel Cell Direct Alcohol Fuel Cell (DAFC) Fuel Processor Fuel Cleaning System Fuel Pure H2 Electricity Fuel Cell Direct Methanol Fuel Cell Direct Ethanol Fuel Cell (DMFC) (DEFC) Reduce CO adsorption on Pt at High Temp Higher power density at high temperature Easy breakage C-C bond in DEFC at High Temp.
    [Show full text]