H2 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
Heilongjiang
Jilin
IMR
Xinjiang
Beijing Liaoning
Gansu
Tianjin
Ningxia
Qinghai
Shenyang
Hebei
Shanxi
Sandong
Jiangsu
Henan Anhui Shanghai
Tibet
Sichuan
Hubei
Zhejiang
Chongqing
jiangxi
Hunan
Fujian
Yunnan
Guangxi
Guangdong
Taiwai
Hongkong
Macau
Hainan
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.
5
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.
6
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.
7
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
－ AB5 Alloy
－ AB2 Nanocrystalline Alloy
－ Ti-NaAlH4 Complex Hydride
－ Mg/MWNTs Composite
9
The AB5 Hydrogen Storage Alloy
 The AB5 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
AB2 Nanocrystalline Alloys

Zr-based AB2 Laves phase alloys consist of cast
polycrystalline and nanocrystalline structure.
Nanocrystalline microstructure could be obtained
from quenching of melt-spun alloys after annealing.
Composition
AB2-1 alloy Zr[(Ni V Mn Co)1-ySny]2+(y=0,0.025,0.05)
AB2-4 alloy(Zr1-xTix)(Ni V Mn Co) 2+(0.05<X<0.15,0<<0.3)
11
SEM Micrographs of the Cast Polycrystalline AB2 Alloys
(a) AB2-1 alloy
(b) AB2-4 alloy
 Microstructures of AB2-1 alloys consist of cubic C15 Laves
phase, hexagonal C14 Laves phase and of AB2-4 is C15
 The white one of non Laves phase in AB2-1 and AB2-4 is
Zr9Ni11 and Zr7Ni10, respectively.
12
TEM Micro-analysis QAB2-4 Alloy
The transmission electron microscopy (TEM) and correlated
electron diffraction patterns of quenched QAB2-4 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.
13
TEM Micrographs and SAED Patterns of QHAB2-4
(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.
14
The Charge-discharge Cycle-life for QHAB2-1 and QHAB2-4
Discharge Capacity(mAh/g)
380
360
340
320
300
280
AB2 -1, as-cast
260
QHAB2-1-heat-treated at 1173K
AB2- 4, as-cast
240
QHAB2-4-heat-treated at 1173K
220
0
50
100
150
200
250
300
Charge-discharge Cycle (n)
The discharge capacity of nanocrystalline electrodes can be
increased to 370mAh/g and cycle life decreased only 3% after
300 cycles.
*
15
Gravimetric H-density (mass%)
Ti-NaAlH4 Complex Hydride
20
18
16
14
12
10
8
6
4
2
0
Target:
LiBH4
Al(BH4)3
LiAlH4
NaBH4
MgH2
Medium &
long-term
Near-term
NaAlH4
CNT
0
20
40
60
80
100 120 140 160
2 3 -3
kgH2/m
Volumetric H-density (kgH
/m )
• We are interested in the sodium aluminum hydride system.
16
High Capacity of KH+Ti co-doped NaAlH4
From P.Wang H.M.Cheng
5
5
+KH+Ti
+LiH+Ti
4
H-capacity, wt.%
H-amount desorbed, wt.%
Potassium hydride and Titanium
3
+Ti
2
1
DH at 150oC
2
4
6
Time, h
After KH addition
4
3
2
High and stable!
1
0
0
4.7%
8
10
1
2
3
4
5
6
7
8
9
10
Cycle Number
• After adding of potassium hydride and Titanium to NaAlH4,
the hydrogen capacity is high and stable.
17
Ti with TiH2 doped to NaAlH4
Kinetic performance
3.0
0.6
+ Ti
+ Ti
2.5
2.0
0.4
1.5
1.0
0.2
o
o
RH at 120 C
DH at 150 C
0.5
0.0
0.0
0
2
4
6
8
10 0 2
Time, h
4
6
8
10
H-amount desorbed, wt.%
+ TiH2
+ TiH2
H-pressure decreased, MPa/g
H-amount desorbed, wt.%
3.5
Cycling performance
3.5
3.5
3.0
3.0
2.5
2.5
2.0
2.0
1.5
1.5
1.0
1.0
0.5
+ Ti
+ TiH2
0.0
0.5
0.0
0
2
4
6
8
10 0 2
Time, h
4
6
8 10 12
Direct utilization of metallic Ti as dopant to prepare Ti-doped
NaAlH4 offers the same performance as TIH2.
18
Intensity (a.u.)
Ti in situ formed TiH2
NaH
Al
Na3AlH6
TiH2
Ti
TiHx (x<2)
cycled
As-milled
20
30
40
50
60
70
80
2 (deg.)
In situ formed Ti hydride keeps its phase stability in ab/desorption cycles
19
Morphological Observation
DH performance
Back Scattering Electron
images
EDS analyses
Counts
H-amount desorbed, wt.%
3.0
1000
(b)
2.5
Ti
Al
Ar 10h
(a)
Na
O
500
2.0
(a)
1.5
0
2
4
6
8
10
Energy(keV)
Counts
1.0
Al
Ar 1h
0.5
1000
(a)
0.0
0
2
4
6
Time, h
8
10
(b)
(b)
O
Na
500
Ti
0
2
4
6
8
10
Energy(keV)
Milling time for 1 h, the sample is metallic Ti. While in the 10 h,
*
particles consist of nanocrystalline TiH2.
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, multiwalled carbon nanotubes (MWNTs).
21
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 MgH2 appeared after
hydriding and dehydriding cycles.
22
Absorption & Desorption Kinetics for Mg- 5 wt.% MWNTs
－ 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
1: 298 K, 2: 373 K, 3: 473 K, 4: 553 K
rates were as the same.
23
PCT Curves for Composite Mg/MWNT-H2 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.
25
The container of thermal hydrogen charging
26
Effect of thermal H2 charging on mechanical properties
Alloy
H
g/g
Yield Strength
(MPa)
Tensile Strength
(MPa)
Elongation
(%)
Reduction of Area
(%)
Uncharged
1.0
233
531
74.5
84.0
H-charged
40.2
255
534
74.3
82.4
Uncharged
1.1
426
776
62.1
79.8
H-charged
70.8
434
768
65.3
73.5
Uncharged
1.2
549
924
48.5
72.5
H-charged
67.2
585
915
49.3
68.5
20#
40#
50#
Thermal H2-charged: 300 oC, 10days, 10MPa, H2 saturated
－20# FeNiCr stainless steel
－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.
29
Tensile Properties of the Alloys
Yield Strength
(MPa)
Tensile Strength
(MPa)
Elongation
(%)
Reduction of Area
(%)
Uncharged
750
1090
28
57
H-charged
760
1110
25
37
Uncharged
762
1051
32.2
61.3
H-charged
748
1042
31.6
45.1
Uncharged
777
1210
55.8
81.2
H-charged
812
1213
20.3
22.8
Alloy
75#
90#
100#
Thermal H2-charged: 300 oC, 10days, 10MPa, H2
30
Typical Microstructure


 size should be controlled within 10 nm, then the H2
could not be settled in the interface between  - .
Then, the degradation of the alloy become small.
31
Other precipitates  phase should be coherent to the Matrix
*
32
4. Conclusions
 AB2 nano-crystalline alloy, Ti-NaAlH4 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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Bei
Jing
One dream
Huan
Ying
Nin
Welcome to
Thank you for your attention
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