Transcript 幻灯片 1 - American Ceramic Society
H 2 STOR-18
Progress of Hydrogen Storage and Container Materials
YiYi LI* YuTuo ZHANG
February 26, 2008 Cocoa Beach, Florida Institute of Metal Research, Chinese Academy of Sciences
Location of IMR Xinjiang Tibet Heilongjiang Gansu Qinghai Ningxia Sichuan Chongqing Yunnan IMR Jilin Beijing Liaoning Tianjin Shanxi Hebei Sandong Henan Anhui Jiangsu Shanghai Hubei jiangxi Zhejiang Hunan Fujian Guangxi Guangdong Hongkong Macau Hainan Taiwai Shenyang 2
Thanks for my colleagues
Dr.Huiming CHENG Dr.Ping WANG Dr.Dong CHEN Dr.Lijian RONG Dr.Xiuyan LI Prof. Lian CHEN Prof.Luming MA Prof.Cungan FAN 3
Outline
Introduction
Hydrogen Storage Materials
Hydrogen Container Materials
Conclusions
1. Introduction
Premier Wen Jiabao tasked that up to 2020 China’s energy consumption per unit GDP decreases of 20%.
Premier Wen also urged that those consuming more energy and releasing more pollutants have to in a bid.
From: http://www.efchina.org/FHome.do
a speech addressed to the national working teleconference on energy saving and pollutants reduction on April 27, 2007.
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The Development Policy for China Automobile
－
Up to the end of 2007, there are 160 million automobiles in China.
－
In order to decrease emission of automobiles, Chinese government supports R&D of clean fuel such as ethanol, NG to hybrid, electric vehicles.
－
Pushing and encouraging EV development.
－
Developing new TiAl valves for cars.
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Alternative Fuel Vehicles
There are 215,000 gas-powered vehicles which are operating with 712 gas-refilling stations.
The number of natural gas-powered vehicles has been ranked the seventh and liquefied petroleum gas vehicles on the 11th in the world.
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Fuel Cell Vehicle Development in China
Hydrogen fuel cell vehicles start development in 1990s.
There are 30kW car and 60kW bus as well as 100kW FC bus.
2008: during the Olympic Games it has demonstration buses with hydrogen fuel cells in Beijing.
60 kW 100 kW 8
2. Hydrogen Storage Materials
－
AB 5 Alloy
－
AB 2 Nanocrystalline Alloy
－
Ti-NaAlH4 Complex Hydride
－
Mg/MWNTs Composite 9
The AB
5
Hydrogen Storage Alloy
The AB 5 hydrogen storage alloy for the production of NiMH batteries has been industrialized in China or international market.
In 2005, global sales volume of the alloy was around 20,000 tons , 60% of which was mainly consumed by small NiMH batteries and with proportion of 40% for dynamic batteries.
Production scale of the alloy reached 12,000 tons in China in 2005.
It is estimated that global demand for hydrogen storage alloy will exceed 40,000 tons in 2010.
* 10
AB
2
Nanocrystalline Alloys
Zr-based AB 2 Laves phase alloys consist of cast polycrystalline and nanocrystalline structure. Nanocrystalline microstructure could be obtained from quenching of melt-spun alloys after annealing. Composition AB 2 -1 alloy Zr[(Ni V Mn Co) 1-y Sn y ]2+
(y=0,0.025,0.05) AB 2 -4 alloy(Zr 1-x Ti x )(Ni V Mn Co) 2+
(0.05
<0.3) 11
SEM Micrographs of the Cast Polycrystalline AB 2 Alloys (a) AB 2 -1 alloy (b) AB 2 -4 alloy
Microstructures of AB 2 -1 alloys consist of cubic C15 Laves phase, hexagonal C14 Laves phase and of AB 2 -4 is C15 The white one of non Laves phase in AB 2 -1 and AB 2 -4 is Zr 9 Ni 11 and Zr 7 Ni 10 , respectively.
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TEM Micro-analysis QAB 2 -4 Alloy The transmission electron microscopy (TEM) and correlated electron diffraction patterns of quenched QAB 2 -4 alloy.
100nm (a) bright field (b) SAED pattern of the white area It was clearly observed that white area has turned into amorphous phase, indicating bright continuous ring.
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TEM Micrographs and SAED Patterns of QHAB 2 -4 (a) bright field (b) dark field (c) SAED patterns
The electron diffraction pattern is discontinuous rings consisting of scattered dots at annealing temperature of 1173K, the alloy has turned into nanocrystalline completely and the grain size is about 80nm.
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The Charge-discharge Cycle-life for QHAB 2 -1 and QHAB 2 -4 380 360 340 320 300 280 260 240 220 0 AB 2 -1, as-cast QHAB 2 -1-heat-treated at 1173K AB 2 - 4, as-cast QHAB 2 -4-heat-treated at 1173K 50 100 150 200 Charge-discharge Cycle (n) 250 300 The discharge capacity of nanocrystalline electrodes can be increased to 370mAh/g and cycle life decreased only 3% after 300 cycles. * 15
Ti-NaAlH
4
Complex Hydride
20 18 16 14 12 10 8 6 4 2 0 0 CNT Target: LiAlH 4 NaAlH 4 LiBH 4 Al(BH 4 ) 3 NaBH 4 MgH 2 Medium & long-term Near-term 20 40 60 80 100 120 140 160 Volumetric H-density (kgH 2 2 /m -3 )
•
We are interested in the sodium aluminum hydride system.
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High Capacity of KH+Ti co-doped NaAlH 4 From P.Wang H.M.Cheng
Potassium hydride and Titanium 1 0 5 4 3 2 +KH+Ti +Ti +LiH+Ti DH at 150 o C 0 2 4 6 8 10 Time, h 5 4 3 2 1 4.7% After KH addition
High and stable!
1 2 3 4 5 6 7 8 9 10 Cycle Number
•
After adding of potassium hydride and Titanium to NaAlH 4 , the hydrogen capacity is high and stable.
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Ti with TiH 2 doped to NaAlH4
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Kinetic performance + TiH 2 + Ti
DH at 150 o C
+ TiH 2 + Ti
RH at 120 o C 0 2 4 6 8 10 0 Time, h 2 4 6 8 10 0.6
0.4
0.2
0.0
Cycling performance
1.5
1.0
0.5
0.0
3.5
3.0
2.5
2.0
0 2 4
+ TiH
6
2
8 10 0 Time, h 2 4 3.5
3.0
2.5
2.0
1.5
1.0
6
+ Ti
0.5
8 10 12 0.0
Direct utilization of metallic Ti as dopant to prepare Ti-doped NaAlH 4 offers the same performance as TIH 2 .
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Ti in situ formed TiH 2
NaH Al Na 3 AlH 6 TiH 2 Ti TiH x (x<2)
cycled As-milled
20 30 40 50 2 (deg.) 60 70 80
In situ formed Ti hydride keeps its phase stability in ab/desorption cycles 19
Morphological Observation
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
DH performance
Ar 10h 2 4 6 Time, h 8 Ar 1h 10
Back Scattering Electron images
Counts
(b)
1000 O Na Al
EDS analyses
Ti
(a)
500
(a)
0 Counts 2 4 6 8 10 Energy (keV) Al
(b)
1000 O
(a)
500 Na
(b)
0 2 4 Ti 6 8 10 Energy (keV)
Milling time for 1 h, the sample is metallic Ti. While in the 10 h, particles consist of nanocrystalline TiH 2 .
* 20
Composite of Mg/MWNTs
Mg- 5 wt.% MWNTs were developed by a catalytic reaction of ball-milling with different materials such as matrix Mg magnesium, multi walled carbon nanotubes (MWNTs).
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XRD Patterns of Hydrogen Storage Composite Mg/MWNTs From: Chen Dong et al (a) Without ball milling; (b) Ball milling for 0.5h; (c) Ball milling for 3 h; (d) After hydriding and dehydriding cycles.
XRD peak of Mg disappeared and hydride MgH 2 hydriding and dehydriding cycles.
appeared after 22
Absorption & Desorption Kinetics for Mg- 5 wt.% MWNTs 1: 298 K, 2: 373 K, 3: 473 K, 4: 553 K
－
At each temperature, 80 % of maximum hydrogen storage capacity can be obtained in 20, 15, 2 and 1 min, respectively.
－
The largest hydrogen absorption rate exhibited at 553K
－
The hydrogen desorption rates were as the same.
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PCT Curves for Composite Mg/MWNT-H 2 System at 2.0 MPa hydrogen pressure The maximum amount of hydrogen storage capacity of Mg-5 wt.% MWNTs is 0.4wt.%,3.4wt.%, 5.7wt.%, 6.2wt.% respectively.
* 24
3. Hydrogen Container Materials
Two kinds of alloys can be applied to hydrogen resistant container:
－
FeNiCr stainless steel and FeNiCr stainless steels strengthened with N and Mn.
－
Nanosize
-precipitates strengthened superalloys.
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The container of thermal hydrogen charging 26
Effect of thermal H 2 charging on mechanical properties Alloy H
g/g Yield Strength (MPa) Tensile Strength (MPa) Elongation (%) Reduction of Area (%) 20# 40# 50# Uncharged H-charged Uncharged H-charged Uncharged H-charged 1.0 40.2 1.1 70.8 1.2 67.2 233 255 426 434 549 585 531 534 776 768 924 915 74.5 74.3 62.1 65.3 48.5 49.3 84.0 82.4 79.8 73.5 72.5 68.5 Thermal H2-charged: 300 o C, 10days, 10MPa, H 2
－
20# FeNiCr stainless steel saturated
－
40# & 50# FeNiCr stainless steels strengthened with N and Mn 27
The Stability of Austenite Alloy Used for H Storage Container Metastable austenite transformed
-
or
-
-
after cooling or deformation, then the hydrogen brittleness or degradation can occur.
From:http://www.outokumpu.com/
- Austenite
-Martensite * 28
Nano-
Strengthened Fe-based Alloys
• • • •
Excellent combination of Hydrogen resistance High strength at room temp. High temperature strength Fe-based alloys better than Ni-based alloys Hydrogen resistance of nano-
strengthened Fe-based alloys is better than other precipitates strengthened alloys.
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Tensile Properties of the Alloys 75# 90# Alloy Uncharged H-charged Uncharged H-charged Uncharged Yield Strength (MPa) Tensile Strength (MPa) Elongation (%) Reduction of Area (%) 750 760 762 748 777 1090 1110 1051 1042 1210 100# H-charged 812 1213 Thermal H 2 -charged: 300 o C, 10days, 10MPa, H 2 28 25 32.2 31.6 55.8 20.3 57 37 61.3 45.1 81.2 22.8 30
Typical Microstructure
size should be controlled within 10 nm, then the H 2 could not be settled in the interface between
-
. Then, the degradation of the alloy become small.
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Other precipitates
phase should be coherent to the Matrix * 32
4. Conclusions
AB 2 nano-crystalline alloy, Ti-NaAlH 4 complex hydride and Mg/MWNTs composite are promising hydrogen storage materials.
It is important to use the stable austenite alloys for hydrogen container materials.
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One world One dream
Bei Jing Huan Ying Nin Welcome to
Thank you for your attention
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