Transformative Renewable Energy Storage Devices Based

on Neutral Water Inputp

E St S t U d tEnergy Storage Systems UpdateARPA-E GRIDS Kick-Off

4 November 20104 November 2010

Team

• Proton Energy SystemsD K th A PI– Dr. Kathy Ayers, PI

– Luke Dalton, System Lead– Chris Capuano Stack 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 Stack2

Fuel Cell Stack

Proton Energy Systems• Manufacturer of Proton Exchange Membrane

(PEM) hydrogen generation products using electrolysis

• Founded in 1996• 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

• Complete product development, manufacturing & testing• Containerization and hydrogen storage solutions

Storage Solutions

• Containerization and hydrogen storage solutions• Integration of electrolysis into RFC systems• Turnkey product installationy p• World-wide sales and service

L b t iH t T ti S i d t GovernmentPower Plants LaboratoriesHeat Treating Semiconductors Government

4

HOGEN® C Series• Maximum Capacity: 30 Nm3/h H2 (65 kg/day) (~200 kW input)• Commercial availability: Q1 2011

5X h d t t ith l 1 5X th f t i t• 5X hydrogen output with only 1.5X the foot print

5

Next Steps in Scale Up• 70 Nm3/h • 150 kg/day• 400 kW input

2.202.252.30

0.6 SQFT 3 Cell (1032 amps, 425 psi, 50oC)

1.952.002.052.102.15

l Pot

entia

l (V)

1.751.801.851.90

0 1000 2000 3000 4000

Cel

l

Run Time (hours)

Cell 1 Cell 2 Cell 3

6

Run Time (hours)

Hydrogen Cost Progression

$10 

$6 

$8 

odel

$

$4 

H2, H2A

 m

$‐

$2 

F lG 65 150 k /d 150 k /d

$/kg H

FuelGen65, current stack

150 kg/day system, next 

generation stack

150 kg/day system, 

advanced stack*

*Assumes volumes

,    product 

introduction

7

*Assumes volumes of 500 units/year

Two Main Types of Low Temp ElectrolysisAlkaline Liquid Electrolyte

Low bubble point requires

Proton Exchange Membrane (PEM)

+ Membrane enables balanced pressure Controlled shutdown required High pressure oxygen

differential pressure+ Load following+ Ambient pressure oxygen

Corrosive solvent Complex balance of plant,

high pressure lines

+ Pure water+ Simple balance of plant,

plastic on O fluids loophigh pressure lines Low current densities+ Less expensive materials

plastic on O2 fluids loop+ High current densities High cost catalysts and flow

of construction fields

Alkaline membrane technology could provide best of both systems

8

gy p y

PEM / AEM Cell Comparison

4H+

Hydrogen+ vapor

Air (O2)+ vapor

Oxygen electrode (cathode)Hydrogen electrode (anode)

Solid polymer electrolyte

4H+

Hydrogen OxygenOxygen electrode (anode)Hydrogen electrode (cathode)

Solid polymer electrolyte

ProtonicWater

ProcessWater, heat

4H +4e+

2H2O+

4H + 4e+O2

4e

(-) (+)

H2 O

ProductWater

+ Depleted Air+ Heat

22H

4H

4H +4e 2H2+

2H2O+

4H + 4e+O2

4

(-) (+)

H2O

ProcessWater

4e

DC Load

Heat 4e

DC Power

Solid Alkaline Membrane

PEMAEM

4OH-

Hydrogen OxygenOxygen electrode (cathode)Hydrogen electrode (anode)

4OH-

Hydrogen OxygenOxygen electrode (anode)Hydrogen electrode (cathode)

Solid Alkaline Membrane

Water

AEM

+ 4e-

4e

(-) (+)Water

H2O2H2 4OH- 2H2O +4e-+ 4OH-O24H2O + 4H2O + 4e-

4e

(-) (+)

DC P

Process Water

H2O2H2+4OH- 2H2O +4e-+4OH- O2

99

DC LoadDC Power

Rationale• Alkaline advantage over PEM: lower cost materials

of construction• Disadvantages of alkaline liquid system:

– Corrosive electrolyte– High pressure oxygen– Complex balance of plant

L it h d– Lower purity hydrogen– Lower efficiency

• Alkaline membranes showing feasibility• Alkaline membranes showing feasibility– Enables PEM advantages at low cost– Enables lower current density for high efficiency

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Enables lower current density for high efficiency

Cost Justification 100%line

• 3-pronged approach40%

60%

80%

ercentage of base

$10 000

$100,000 

b

0%

20%

40%

40 kW 220 kW 500 kW

$/kW

 cost a

s pe

$10

$100 

$1,000 

$10,000 

Raw M

aterial $/lb 40 kW 220 kW 500 kW

System Capacity

$1 

$10 

Platinum Iridium Nickel Titanium Stainless 

Catalyst  Flow fields

R

MaterialLabor minimization and hi h d f t ihigh speed manufacturing at high production volume

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Proposed Approach• Design Trade Study

– Select RFC configuration• Membrane and Ionomer Development

– Maximize durability and minimize ionic resistance and crossover• Catalyst Development y p

– Reduce activation overpotential• MEA Fabrication

Optimize catalyst membrane interaction– Optimize catalyst-membrane interaction• Cell Stack Design

– Leverage Proton experience and substitute materials• System Design

– Leverage Proton balance of plant designs• Cost Analysis

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Cost a ys s

DRFC – Discrete RFC– Separate fuel cell and

l t l t kTrade Study:C fi ti O ti

URFC – Unitized RFC

electrolyzer stacks

Fuel CellElectrolyzer

Regenerative Fuel Cell

Configuration Options

– A single cell stack that operates as both fuel cell and electrolyzer

hydrogen

DC electricity DC electricity oxygen

Unitized Regenerative Fuel Cell

water

Regenerative Fuel CellDC electricity oxygen

Unitized Regenerative Fuel Cell

h d

DC electricity DC electricity oxygen

Fuel CellElectrolyzerair

hydrogen

hydrogen

water

water

13

Trade Study – Electrolysis Example

2 5

Polarization Comparison

Flow URFC Flow EC

2

2.5

} 1.5

Volts

}~300 mV loss for URFC

0.5

1V

00 500 1000 1500 2000 2500 3000 3500

14

Current Density (mA/cm2)

Trade Study: O2 vs. air feedy 2

• High pressure oxygen adds balance of plant

• Membrane is sensitive to COadds balance of plant

complexity• Requires special

CO2

• Carbonate can replace OH- sites and reduceRequires special

cleaning >150 psi• O2 feed requires drying

OH sites and reduce conductivity

• Removal of carbon from of both gases air reduces efficiency

and increases cost

Need to look at trade of cost, efficiency, and simplicity in context of safety considerationsin context of safety considerations

15

Trade Study: Anode vs. Cathode FeedPEM l t l iAlkaline electrolysis

• Water consumed on oxygen side of cell

PEM electrolysis• Water consumed on hydrogen

side of cell• Hydrogen is typically gas of

interest, oxygen vented• Hydrogen primary interest

4e‐4e‐

2H22H2 + 4OH‐ O2 + 4H+O2 + 2H2O

4e4e

H+OH‐

4H

2e‐Anode Cathode Anode Cathode

4H+

2H2O 2H2O4OH‐

Alkaline Acid

16

Trade Study: PEM Comparison

oltage

Relative vo

Cathode feed

Anode feed

R

0 500 1000 1500 2000C t d it ( A/ 2)Current density (mA/cm2)

17

Membrane and Ionomer Development• Penn State-led effort to develop an anion

exchange membrane (AEM) and ionomer binderReduced cost through use of commercially available– Reduced cost through use of commercially available monomers

– “Tune” ion exchange capacity and cross-linking to b l d ti it d h i l ti /balance conductivity and mechanical properties/gas cross-over.

• Proton to assist with characterization– Conduct diffusion and performance evaluation to

provide feedback on how to iterate on configurationHa e Tok ama membranes and ionomers to test as a– Have Tokuyama membranes and ionomers to test as a baseline for AEMs.

18

Catalyst Development• Apply processes from

PEM experience to AEM catalystcatalyst

19

MEA Fabrication• Vary temperature and dwell time

– Find combination most conducive to electrode attachment

• Sub-scale membrane samples to be used for pressing half MEAshalf-MEAs– Two fabrication approaches to be considered

• Trials rated on uniformity, adhesion to membrane, and degree of flow for ink samples. M b d f h i l d d ti• Membrane assessed for mechanical degradation resulting from process

20

Electrolysis Stack DesignWill i f h d d• Will incorporate outputs from the trade study to dictate configuration

Bipolar plate design (high efficiency low pressure)– Bipolar plate design (high-efficiency, low-pressure)– Round design (lower-efficiency, high pressure)

• Primary effort will be material substitutiony– Alkaline allows replacement of titanium components with stainless

steel.

Solid Plate

Inserts

Bipolar plate design

21

Round architecture Bipolar plate design

Electrolysis Cell Modeling

temperature distribution current density distribution

J

oxygen transport

JO2

yg p

22

Fuel Cell Modeling

current density distribution Liquid water distributioncurrent density distribution Liquid water distribution

23

Electrolysis and Fuel Cell Stack Test Plany• Design phase and concept review• Prototype flow field fabricated using production• Prototype flow field fabricated using production

tooling and techniques• Anode flow field verificationAnode flow field verification• Cathode flow field verification• Short stack testing and operation for prototype• Short stack testing and operation for prototype

review• Deliverable stack assembly and operationDeliverable stack assembly and operation

24

Cell Stack Operational Verificationp

• Multi-cell operational testing• Allows for fine control over operating parameters

– Temperature– Generation Pressure– Current Control

W t Fl R t– Water Flow Rates

25

Energy Storage System Design• PEM system should be largely transferrable to

proposed AEM-based systemCommon fluids of interest (H H O O )– Common fluids of interest (H2, H2O, O2)

• Trade study work will impact type of system• Leverage prior experience in closed loop REFCsLeverage prior experience in closed loop REFCs• Output:

– Design Intent Documentg– P&ID– Component selection (comprehensive BOM)

H d d i i– Haz-op and design review

26

Alkaline REFC Approach• Well-suited to load-following• Easily scalabley

27

Figure 1. Closed-loop, pure oxygen, discrete regenerative fuel cell system P&ID.

Examples of Demonstrated Energy Storage Systems

“Regenerative Fuel Cell” integratedinto CERL’s Silent Camp system concept

Missile Defense Agency: Cl d l RFC

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Closed loop RFC

Near-Term Milestones

• Kickoff meeting – October 6, 2010T d t d lt di t iti d t k• Trade study results on discrete vs. unitized stack

• Initial survey of commercial catalysts• MEA formulation studies with baseline membrane

and catalystS f t k t il bilit i lt t• Survey of stack part availability in alternate materials

29

Major Project Milestonesj j

• System Configuration Trade StudyEl t l i d F l C ll M b M t i l• Electrolysis and Fuel Cell Membrane Material ImprovementsEl t l i d F l C ll M b El t d• Electrolysis and Fuel Cell Membrane-Electrode-Assembly Fabrication Optimization

• Fuel Cell Stack Design and Test• Fuel Cell Stack Design and Test• Electrolysis Stack Design and Test

I t t d E St S t D t ti• Integrated Energy Storage System Demonstration

30