E lectrochemical R eaction & T echnology L aboratory (ERTL) System development of Portable fuel cells System development of Portable fuel cells System development of Portable fuel cells System development of Portable fuel cells Portable fuel cell system s Jaeyoung Lee September 19, 2006
http:/ / w w w .h2 fc.re.kr Energy dem and & fuel cells Energy demand 세계에너지 수요공급 전망 mW 3kW 75kW MW 세계에너지 수요공급 전망 Capac ity 2W 50W Capac ity PFC PFC Applic ation Applic ation � � � � Mic ro Mobile L ab-top Small-sc ale E le c tric Distrib ute d Po we r po we r syste m pla nt de vic e po we r pla nt Ve hic le phone c omputer MCF C (Source: Energy Needs, Choices and Possibilities, (Source: Energy Needs, Choices and Possibilities, MCF C Scenarios to 2050, Shell) Scenarios to 2050, Shell) PEMFC (H PEMFC (H 2 ) PEMFC (H PEMF C (H 2 ) F uel Cells F uel Cells DMFC DMFC 30% 30% DLFC DMFC DMFC PAF C PAF C μ -FC -FC μ -FC -FC SOF C SOF C Pow er range: a few ~ ca . 3 kW 5
http:/ / w w w .h2 fc.re.kr I SSUES in com m ercialization CATALYSTS MEMBRANES Fuel Cells BPP & GASKETS STACK EDUCATION SAFETY & COST CODE & STANDARD I SSUES INFRASTRUCTURE BATTERY BATTERY BOP PUMPS & Valve CUSTOMERS PCB BOARD (PMS) acceptance Fuel tank
http:/ / w w w .h2 fc.re.kr Choices μ - μ -SOFC SOFC PFC PFC μ -reformer & � NaBH 4 � PEMFC PEMFC DLFC DLFC (FA, MeOH)
http:/ / w w w .h2 fc.re.kr
http:/ / w w w .h2 fc.re.kr Portable energy system s DC power charging Li polymer/ ion battery 3 ~ 4 hrs Methanol, Micro PEMFC with reformer gasoline & butane, etc. Portable application NaBH 4 + NaOH IT devices PEMFC with NaBH 4 � Hydrogen Military systems Emergency case Formic acid Direct liquid fuel cells Methanol Ethanol
http:/ / w w w .h2 fc.re.kr LG Chem Components ~ 1.0L Fuel tank ~ 0.2L Sep. 2005 Average power = 25 W 10 hrs operation
http:/ / w w w .h2 fc.re.kr SAMSUNG Nov. 2005 Systems ~ 1.0L (230 x 82 x 53 mm 3 ) Fuel tank ~ 0.2L April 2004 Average power = 20W 15hrs operation
http:/ / w w w .h2 fc.re.kr TOSHI BA CeBIT 2004 CeBIT 2005 PORTEGE M300 B5-sized sub-notebook PC PORTEGE M100 B5-sized sub-notebook PC � Systems ~ ca. 1.0L � Fuel tank ~ ca. 0.2L � 20Whr � 10hrs operation
http:/ / w w w .h2 fc.re.kr ANTI G CeBIT 2005 � Systems ~ ca. 1.0L > � Fuel tank ~ ca. 0.2L � 10W CeBIT 2006 � CD-Rom size � 45W / 8hrs � 1.7kg � Antig & AVC
http:/ / w w w .h2 fc.re.kr Fuel tank = 250cc Systems ~ 1.0L 10hr operation NEC WPC EXPO 2004 Oct. 2004
http:/ / w w w .h2 fc.re.kr July 2004 HI TACHI
http:/ / w w w .h2 fc.re.kr Fujitsu & Millennium cell Jan. 2004 Systems ~ ?.?L 10hr operation Ave. = 15W
http:/ / w w w .h2 fc.re.kr Panasonic
http:/ / w w w .h2 fc.re.kr Sanyo & I BM April 2005 weighs 4.4 pounds 8 hrs operation a single 8-cubic inch fuel cartridge
http:/ / w w w .h2 fc.re.kr Production model will be available in 2007 UltraCell
http:/ / w w w .h2 fc.re.kr Sam sung SDI Butane- PEMFC Power pack � 220g 소형 부탄 캔 � 100W 평균 출력 / 5 시간 이상 사용 � 레저용 소형 컬러 TV (60W 기준 )/ 8 시간 � 노트 PC (20W 기준 ) 는 20 시간 � 2007 년 말 � 상용화 예정
http:/ / w w w .h2 fc.re.kr P-SOFC: Adaptive Materials, Inc.
http:/ / w w w .h2 fc.re.kr 20W P-SOFC (AMI)
http:/ / w w w .h2 fc.re.kr Direct liquid fuel cells Anode: CH 3 OH + H 2 O = CO 2 + 6H + + 6e - Cathode: 1.5 O 2 + 6H + + 6e - = 3H 2 O Overall: CH 3 OH + 1.5O 2 = CO 2 + 2H 2 O HCOOH + 1.5O 2 = CO 2 + H 2 O HCHO + O 2 = CO 2 + H 2 O C 2 H 5 OH + 3O 2 = 2CO 2 + 3H 2 O Liquid fuels flow
http:/ / w w w .h2 fc.re.kr Alternative liquid fuels Methanol Formic Acid Dimethyl Ether Ethanol (CH 3 OH) (HCOOH) (CH 3 OCH 3 ) (CH 3 CH 2 OH) # of generated 6 2 12 12 electrons Boiling Temp. ( o C) 65 100 -23 78 Energy Density 4690 2086 - 6280 (Wh/L) Kinetics slow very fast slow very slow Cross-over large small small ?? - Toxicity toxic non-toxic? toxic non-toxic High temp. etc - - gas reaction
http:/ / w w w .h2 fc.re.kr DLFC components to systems Electrode Catalyst synthesis Catalyst Electrode fabrication Membrane-electrode Polymer Electrolyte assembly (MEA) Membrane Stack System Graphite bipolar plate
http:/ / w w w .h2 fc.re.kr 50W DMFC Stacks 50W DMFC Stacks Number of cell 6 Electrode area 106 cm 2 Cell pitch 3.8mm Stack 49x105x161 (mm) Temperature Room temperature Operation conditions 2M MeOH @ 25CC/min & Air 12slm MEA Membrane Nafion-115 Anode 5mg PtRu/cm 2 Cathode 5mg Pt/cm 2 Maximum Performance = 54W, 90mW/cm 2 60 Stack Power 4.0 7 slm Dry Air Maximum Power Density 50 12 slm Dry Air 2 M MeOH 120 3.5 17 slm Dry Air 1.5 M MeOH 2 ) 1 M MeOH 40 Power Density (mW/cm Voltage (V) 0.5 M MeOH 100 3.0 Power (W) 30 80 2.5 20 60 2.0 10 40 1.5 0 20 1.0 0 5 10 15 20 25 30 35 0 Current (A) Cell 1 Cell 2 Cell 3 Cell 4 Cell 5 Cell 6
http:/ / w w w .h2 fc.re.kr LCD TV ( 5 0 W ) operation Gas-liquid separator 2004 August 2004 August STACK x � 12V DC-DC converter Liquid pump Fuel tank (1.5M/500cc) PROBLEMS PROBLEMS (a) low cell potential of about 2.3V � low conversion efficiency (ca. < 70%) (b) Uneasy of heat management: over 80 ° C
http:/ / w w w .h2 fc.re.kr Direct formic acid fuel cells � High thermodynamic potential CO 2 O 2 H + H + � e e Fast oxidation kinetics H + H + e e � Lower cross-over e e H + H + � Non-toxic & Easy handling of fuels e e H 2 O HCOOH H + H + � Low temp. operation HCOOH → CO 2 + 2H + + 2e - � Simple device Anode: 1/2 O 2 + 2H + + 2e - → H 2 O Cathode: � Sufficient fuels HCOOH + 1/2 O 2 → CO 2 + H 2 O 1.45 V
KI ST DLFC system
http:/ / w w w .h2 fc.re.kr Goal in 2005 Summer - Dem onstration Mixing Chamber & Control Valve Fuel Cartridge BOP 2005: 600cc Lap- Lap -top computer top computer 2007: 300cc Sensor Liquid Recirculation Pump Gas-Liquid Air Compressor Separator Power Regulation Device & battery Fuel Cell Stack Fuel Cell Stack 2005: 30W/600cc 2007: 30W/500cc (6.0V, 5.25A) Air Blower Control Electronics
http:/ / w w w .h2 fc.re.kr 5 m onths later
http:/ / w w w .h2 fc.re.kr Stack development � 15 cells stack � Max power : 50 W � Normal power: 25W (5.6V, 4.5A) � Size: 88 x 70 x 50 (mm) , 308 cc
http:/ / w w w .h2 fc.re.kr The test of small DFAFC stack I nteresting zone 1.8 80 � 6 M FA � am bient air 1.6 70 � Anode: PtRu p (mW cm-2) and T (oC � Cathode: Pt 1.4 60 � Nafion 115 1.2 50 V 1 E (V) 40 V/Cell 0.8 p 30 0.6 20 0.4 10 0.2 � OCV : 1.664 V � 0.555V 0 0 � Max (P) : 74.7 mW/ cm 2 0 50 100 150 200 250 (continuously increasing) i (m W cm -2)
http:/ / w w w .h2 fc.re.kr Optimization of stack materials SEALING is most important issue in a stacking of the cell SEALING s most important issue in a stacking of the cell Compatible Sealing Gasket Material Other Considerations with FA Integrity red silicone Medium NO fail under higher compression PTFE Yes NO easy to manufacture Gasket glassy epoxy No NO difficult to manufacture PTFE-coated epoxy Yes NO difficult to manufacture grey silicone Medium YES inconsistent thickness epoxy+silicone Medium YES labor intensive adhesive PTFE Yes YES simple and efficient 0.7 70 0.6 60 p (mW cm-2) 0.5 50 0.4 40 E / V 0.3 30 Bipolar Plate 0.2 20 Composite Material 0.1 10 Graphite Material 0 0 0 50 100 150 200 i (mA cm -2 )
http:/ / w w w .h2 fc.re.kr Optimization of operation conditions Concentrations 2 M CH 3 OH 2 M CH 3 OH 10 M HCOOH 0.7 6 M HCOOH 140 45 10 M HCOOH 13 M HCOOH 0.6 120 40 o C 0.5 100 P / mW cm Temp / E / V 0.4 80 35 0.3 60 0.2 40 30 Temperature -2 0.1 20 25 0.0 0 0 100 200 300 400 500 0 100 200 300 400 500 -2 I / mA cm -2 I / mA cm 250 cc/min 1.5 cc/min 0.6 500 cc/min 100 0.6 80 3.0 cc/min 750 cc/min 4.5 cc/min 0.5 0.5 80 60 0.4 0.4 P / mW cm P / mW cm 60 E / V E / V 0.3 40 0.3 40 0.2 0.2 20 -2 -2 20 0.1 0.1 0.0 0 0.0 0 0 50 100 150 200 250 300 0 100 200 300 400 -2 I / mA cm -2 I / mA cm Formic acid flow rate. Air flow rate.
http:/ / w w w .h2 fc.re.kr PMS block diagram for DLFC
http:/ / w w w .h2 fc.re.kr Home-built PCB board � Liquid pump: 7.1 V operation � cooling fan: 3ea (12V operation) � Air pump:12V operation � Voltage range: 4.5V ~ 8.3V (buffer) � Initial start-up: double touch of 8.3V � Current range: max. 7.5A � Battery capacity: <10whr board size: PCB board (with case) size: 80mm x 60mm x 20mm (96cc)
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