Development of Mg-Ni Composite Hydrogen Storage by Mechano-Chemical Method

(1)

Development of Mg-Ni Composite Hydrogen Storage by Mechano-Chemical Method

Yuya M

IYAGAWA*,

Yuki Y

OSHIDA*,

Shinya Y

AMANAKA*,

Hiroshi M

IO*,

Yoshiyuki S

HIRAKAWA*,

Atsuko

SHIMOSAKA*

and

J

usuke

H

IDAKA*

(

Received July 14, 2007)

Fuel cell is paid attention as pollution-free electrical generating system for next-generation. In order to make it practicable, hydrogen storage materials being able to absorb much hydrogen in volume standard must be invented. Surface structure and inner microstructure of the materials have much effect on hydrogenation and dehydrogenation characteristics. Therefore, in this research, we made Mg-Ni composite and Mg-Ni alloy by mechano-chemical method which can control structure of the materials and investigate the relationship between structures of the materials and hydrogenation or dehydrogenation characteristics by means of XRD, EDX, PCT, and DSC. From analysis of structural changes and hydrogen absorption data, Mg-Ni alloy was generated between Mg and Ni interfere with hydrogen transfer between Mg and Ni. As a result, hydrogenation and dehydrogenation characteristics became worse. It means that it is important to get much interface of Mg-Ni for making useful hydrogen storages. Moreover, it was shown that there are correlations between crystallite size and hydrogenation in this research.

-G[YQTFUhydrogen storage material, mechano-chemical, Mg, Ni, structure

ࠠ࡯ࡢ࡯࠼᳓⚛⾂⬿᧚ᢱ㧘ࡔࠞࡁࠤࡒࠞ࡞㧘ࡑࠣࡀࠪ࠙ࡓ㧘࠾࠶ࠤ࡞㧘᭴ㅧ

ࡔࠞࡁࠤࡒࠞ࡞ᴺߦࠃࠆ Mg-Ni ⶄวൻ᳓⚛⾂⬿᧚ᢱߩ㐿⊒

ችᎹ ଆ਽㧘ศ↰ ⚿ၔ㧘ጊਛ ⌀਽㧘ਃየ ᶈ㧘⊕Ꮉ ༀᐘ㧘ਅဈ ෘሶ㧘ᣣ㜞㊀ഥ

1. ߪߓ߼ߦ

Άᢱ㔚ᳰߪ㧘ੑ㉄ൻ὇⚛ߥߤߩⅣႺᳪᨴ‛⾰ࠍឃ

಴ߒߥ޿ᰴ਎ઍߩ⊒㔚ࠪࠬ࠹ࡓߣߒߡᵈ⋡ߐࠇߡ޿

ࠆ㧚Άᢱߢ޽ࠆ᳓⚛ߪᏱ᷷࡮Ᏹ࿶ߢ᳇૕ߢ޽ࠆߚ߼

ߦ૕ⓍၮḰߩࠛࡀ࡞ࠡ࡯ኒᐲߪૐߊ㧘Άᢱ㔚ᳰߩታ

↪ൻߦߪ᳓⚛ࠍ❗ዊߒߡ⾂߃ࠆ᳓⚛⾂⬿᧚ᢱߩ㐿⊒

߇ᔅⷐߣߥࠆ㧚

Mg 㧘 Pd 㧘Ꮧ࿯㘃ߥߤߩ㊄ዻߪ᳓⚛ߣ෻ᔕߒߡ᳓⚛

ൻ‛ࠍᒻᚑߒ㧘᳓⚛ߩ૕Ⓧࠍ⚂ 1/1000 ߦ❗ዊߒߡ㊄ ዻ⚿᥏ߩᩰሶ㑆ߦ⾂߃ࠆߎߣ߇ߢ߈ࠆߚ߼㧘᦭↪ߥ

᳓⚛⾂⬿᧚ᢱߣߒߡᦼᓙߐࠇߡ޿ࠆ

¹⁾

㧚߹ߚ᳓⚛⾂

⬿᧚ᢱߣߒߡ↪޿ࠆߦߪ㜞޿᳓⚛᡼಴⢻ജ߽౗ߨ஻

߃ߥߌࠇ߫ߥࠄߥ޿㧚ߒ߆ߒ㧘ߎࠇࠄߩ㊄ዻߪ᳓⚛

ๆ⬿⢻ജߩ㜞ߐߦ෻ߒߡ᳓⚛ൻ‛߇቟ቯߢ޽ࠆߚ߼

ߦ᳓⚛᡼಴⢻ജߪૐ޿㧚ߘߎߢߎࠇࠄߩ㊄ዻߦ㧘 Ni 㧘 Fe ߥߤߩ᳓⚛ߣ෻ᔕᕈߩૐ޿㊄ዻࠍⶄวൻߔࠆߎ ߣߢ㧘᳓⚛ൻ‛߇ਇ቟ቯൻߒ㧘᳓⚛᡼಴⢻ജߪะ਄

ߔࠆߣ޿ࠊࠇߡ޿ࠆ㧚ߣߊߦන૕ߢߪᦨ߽᳓⚛ๆ⬿

㊂ߩ㜞޿ Mg ߣ㧘᳓⚛ಽሶࠍේሶ⁁ᘒߦߒߡౝㇱ᜛

ᢔߔࠆߎߣ߇น⢻ߥ Ni ߩⶄว᧚ᢱߪታ↪ൻߦᦨ߽

ㄭ޿ߣߐࠇߡ޿ࠆ㧚

ߎߩ Mg ߣ Ni ߩⶄว᧚ᢱߩ૞⵾ᣇᴺߩ৻ߟߣߒߡ ࡔࠞࡁࠤࡒࠞ࡞ᴺ߇޽ࠆ㧚ࡔࠞࡁࠤࡒࠞ࡞ᴺߪੑ⒳

એ਄ߩ㊄ዻ☳ᧃߦᯏ᪾⊛ࠛࡀ࡞ࠡ࡯ࠍਈ߃ࠆߎߣߢ

⚿ว⁁ᘒࠍᄌൻߐߖ㧘‛ℂൻቇ⊛ᕈ⾰ߦᄌൻࠍᒁ߈

⿠ߎߔᣇᴺߢ޽ࠆ㧚ߎߩᣇᴺߪࠕࡠࠗࡦࠣ

²⁾

㧘⴫㕙

*Department of Chemical Engineering and Materials Science, Doshisha University, Kyoto Telephone: +81-774-65-6590, E-mail: [email protected]

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Fig. 1. Schematic diagram of the PCT device.

ᡷ⾰

³⁾

㧘ᓸ☸ሶⶄวൻ

⁴⁾

ߥߤߦᔕ↪ߐࠇߡ߅ࠅ㧘․

ቯߩ⚿᥏⁁ᘒࠍᜬߚߥ޿ࠕࡕ࡞ࡈࠔࠬ㊄ዻ☳૕ߩ૞

⵾ߥߤ㧘᧚ᢱߩᓸ᭴ㅧࠍᄌ߃ࠆߎߣ߇ߢ߈ࠆ㧚᳓⚛

ๆ᡼಴․ᕈߪ᧚ᢱߩ⴫㕙᭴ㅧ߿ౝㇱߩᓸ᭴ㅧߦᄢ߈ ߊᓇ㗀ߐࠇࠆ

⁵⁾

㧚ߘߎߢᧄ⎇ⓥߢߪ㧘ㆆᤊࡏ࡯࡞ࡒ

࡞ࠍ↪޿ߚࡔࠞࡁࠤࡒࠞ࡞ᴺߦࠃࠅ Mg ߣ Ni ߩⶄว

᧚ᢱࠍ૞⵾ߒ㧘ߘߩ᳓⚛ๆ⬿㊂ߣ⣕᳓⚛ൻ᷷ᐲࠍ㧘 ⶄว᧚ᢱߩ᭴ㅧ߆ࠄ⠨ኤߒ㧘ታ↪᧚ᢱߩ⸳⸘ߦ᦭↪

ߥ⍮⷗ࠍᓧࠆߎߣࠍ⋡⊛ߣߒߚ㧚

ታ㛎ᣇᴺ ⹜ᢱ૞⵾

Mg( ࠽ࠞ࡜ࠗ࠹ࠬࠢᩣᑼળ␠㧦⚐ᐲ 98%) ߣ Ni( ࠾

࡜ࠦᩣᑼળ␠㧦⚐ᐲ 99.99%) ࠍߘࠇߙࠇ 0.91g 㧘 1.09g

♖⒊ߒߚ㧚ߎࠇߪว㊄ Mg

2

Ni ߩ⚵ᚑᲧ߆ࠄ▚಴ߒߚ ୯ߢ޽ࠆ㧚ౝᓘ 4cm 㧘㜞ߐ 4cm 㧘ኈⓍ 45ml ߩ SUS304

⵾ኈེߦหߓߊ SUS304 ⵾ߩ⋥ᓘ 5 ߥࠄ߮ߦ⋥ᓘ 15mm ߩࡏ࡯࡞ࠍ⹜ᢱߣߣ߽ߦኽ౉ߒ☳⎈ࠍⴕߥߞ ߚ㧚ࡏ࡯࡞ߩలႯ₸ߪኈེߩኈⓍߩ 40% ߣߒߚ㧚ࡒ

࡝ࡦࠣߩ࿁ォㅦᐲߪ 400rpm ߣߒ㧘࿁ォᤨ㑆ߪ 2 㧘 5 㧘 10 㧘 30 㧘 50h ߣߒߚ㧚߹ߚ៺ᡂᾲߦࠃࠆኈེౝㇱߩ

᷷ᐲ߇ㆊᐲߦ਄᣹ߔࠆߩࠍ㒐ߋߚ߼㧘 1 ᤨ㑆ߩಣℂ

ᤨ㑆ߏߣߦ 10 ಽ㑆ⵝ⟎ࠍભᱛߒߚ㧚

: ✢࿁᛬ᴺߦࠃࠆ᭴ㅧ⸃ᨆ

૞⵾ߒߚ⹜ᢱߩ᭴ㅧߪ X ✢࿁᛬ⵝ⟎ (RIGAKU ⵾

RINT2500) ࠍߦࠃࠅ⸃ᨆߒߚ㧚⹜ᢱࡎ࡞࠳ߦߪࠟ࡜

ࠬ⵾ߩ᧼⁁ࡎ࡞࠳ࠍ↪޿ߚ㧚᷹ቯ᧦ઙߪ㧘▤㔚ᵹ 200mA 㧘▤㔚࿶ 40kV 㧘⊒ᢔࠬ࡝࠶࠻ 1° 㧘ᢔੂࠬ࡝

࠶࠻ 1° 㧘ฃశࠬ࡝࠶࠻ 0.15mm 㧘ࠬࠠࡖࡦࠬࡇ࡯࠼

0.6°/s 㧘ࠬ࠹࠶ࡊ᏷ 0.004/s ߢ⿛ᩏ▸࿐ߪ 30 㨪 55° ߣߒ ߚ㧚

᳓⚛ๆ⬿㊂᷹ቯᣇᴺ

૞⵾ߒߚ⹜ᢱߩ᳓⚛ๆ⬿㊂ߪ PCT ⹏ଔⵝ⟎ ( ࡜࠙

ࡦ࠼ࠨࠗࠛࡦࠬ⵾ RSH-1000) ࠍ↪޿ߡ᷹ቯߒߚ㧚

Fig. 1

ߦⵝ⟎ߩ᭎ⷐࠍ␜ߔ㧚ߎߩⵝ⟎ߩ᷹ቯᣇᴺߪ

ࠫ࡯ࡌ࡞࠷ᴺ㧔ኈ㊂ᴺ㧕ߢ޽ࠆ㧚ࠫ࡯ࡌ࡞࠷ᴺߣߪ㧘

㊄ዻ᳓⚛ൻ‛ߩ⚵ᚑ╬᷷✢㧔 PCT ✢㧕ࠍ᷹ቯߔࠆߚ

߼ߩᣇᴺߢ㧘ቯኈ㧘ቯ᷷ਅߢ㊄ዻ᳓⚛ൻ‛ߣ෻ᔕߒ

ߚ᳓⚛ๆ⬿㊂㧘߹ߚߪ㧘᡼಴㊂ࠍ᳓⚛ࠟࠬߩ࿶ജᄌ ൻߣᣢ⍮ߩኈ㊂୯߆ࠄ᳞߼ࠆ

⁶⁾

㧚߹ߕ㧘⹜ᢱࠍ⚂ 0.1g

⒊ࠅߣࠅ㧘⹜ᢱኈེߦ౉ࠇ㧘ᵴᕈൻಣℂߣߒߡ㧘 473K ߢ 1 ᤨ㑆߶ߤ⌀ⓨ⣕᳇ಣℂࠍⴕ߁㧚ᰴߦ㧘 He ࠟࠬ

(1MPa) ߢ⹜ᢱኈེߩኈ㊂ࠍ᳞߼ࠆ㧚ߘߩᓟ㧘 1MPa ߢ H

2

ࠟࠬࠍዉ౉ߒ㧘ฦ⹜ᢱߩᦨᄢ᳓⚛ๆ⬿㊂ࠍ߽ߣ

߼ߚ㧚߹ߚ㧘᳓⚛ๆ⬿ߩߚ߼ߦ㧘᳓⚛ๆ⬿㊂߇㘻๺

୯ߦ㆐ߔࠆ߹ߢ㧔 24 ᤨ㑆㧕᡼⟎ߒߚ㧚⥄േൻⵝ⟎ ( ࠠ

࡯ࠛࡦࠬ⵾ NR-500) ߢ⹜ᢱኈེౝߩ 10 ⑽Ფߩ࿶ജ୯ ࠍ⺒ߺขࠅ㧘એਅߩᑼ (1) ߦࠃߞߡ᳓⚛ๆ⬿㊀㊂⊖ಽ

₸㧔 wt% 㧕ߩᄌൻ㊂Ӡ

W

ࠍ⸘▚ߒߚ㧚

ߎߎߢ㧘

pd

㧘

vd

㧘

Td

ߪߘࠇߙࠇ᷹ቯ♽ߩ࿶ജ㧘ኈⓍ㧘

᷷ᐲ㧘

pr

㧘

vr

㧘

Tr

ߪ⹜ᢱኈེౝߩ࿶ജ㧘ኈⓍ㧘᷷ᐲߢ

޽ࠆ㧚߹ߚ

R

ߪ᳇૕ቯᢙ㧘

X

ߪ⹜ᢱ㊀㊂ߢ޽ࠆ㧚

᳓⚛᡼಴᷷ᐲ᷹ቯᣇᴺ

⹜ᢱߩ᳓⚛᡼಴᷷ᐲߪ㜞࿶␜Ꮕ⿛ᩏᾲ㊂ಽᨆⵝ⟎

( ࡝ࠟࠢ⵾ Thermo Plus 2 / DSC8230HP) ࠍ↪޿ߡ᷹ቯ ߒߚ㧚⹜ᢱ߅ࠃ߮ၮḰ‛⾰ࠍ⚂ 5mg ߕߟἹߩਛߦ⟎

߈㧘 30 ಽ߶ߤ⌀ⓨ⣕᳇ࠍⴕߞߚ㧚ߘߩᓟ㧘 1MPa ߩ

᳓⚛㔓࿐᳇ߦߒ㧘᣹᷷ㅦᐲ 1K/min ߢ 773K ߹ߢടᾲ ߒߚ㧚ߎߎߢᓧࠄࠇߚๆᾲࡇ࡯ࠢ㧔⣕᳓⚛ൻ㧕ߩ⋧

ォ⒖᷷ᐲࠍ⺒ߺขߞߚ㧚

ታ㛎⚿ᨐ ࡒ࡝ࡦࠣߦࠃࠆ⚿᥏᭴ㅧᄌൻ

ᯏ᪾⊛ࠛࡀ࡞ࠡ࡯߇⹜ᢱߩ᭴ㅧᄌൻߦ෸߷ߔᓇ㗀 ࠍᬌ⸛ߔࠆߚ߼ߦ㧘 X ✢࿁᛬ࡄ࠲࡯ࡦߩᤨ㑆ᄌൻࠍ

SV : Stop Valve G : Pressure gage NV : Needle Valve SV

SV

SV SV

SV NV Pressure regulator

G

(Purge) G (H₂)

(He)

Purge flow meter

Vacuum pump Sample vessel H₂

He SV

SV

SV SV

SV NV Pressure regulator

G

(Purge) G (H₂)

(He)

Purge flow meter

Vacuum pump Sample vessel H₂

He

» »

¼ º

« «

¬ ª

¸¸ ¹

¨¨ ·

©

§

c

¸¸ ¹

¨¨ ·

©

§

'

d d r r r r

r r d

d d

T v T p v T

v p T

v p W 201 RX . 6

(1)

(3)

2ǰ[degree]

Intensity [-]

㬍

䂦䂦䂦

Mg Ni

㬍MgO ^䂦Mg2Ni

2ǰ[degree]

Intensity [-]

㬍

䂦䂦䂦

Mg Ni

㬍MgO ^䂦Mg2Ni

Fig. 2. X-ray diffraction patterns of Mg-Ni with milling time .

Fig. 3. EDX image of Mg-Ni after 10 hours milling.

External force from balls

⺞ߴߚ㧚ߘߩ⚿ᨐࠍFig. 2ߦ␜ߔ㧚

Mg

^ߣ

Ni

^ߩࡇ࡯

ࠢߪࡒ࡝ࡦࠣߩㅴⴕߣߣ߽ߦᒙߊߥࠅ㧘

Mg

^ߩࡇ࡯

ࠢߪ㜞ⷺᐲ஥ߦࠪࡈ࠻ߒߡ޿ࠆ㧚ߎࠇߪ㧘ਈ߃ߚᯏ

᪾⊛ࠛࡀ࡞ࠡ࡯ߦࠃࠅ⹜ᢱߩ⚿᥏᭴ㅧߦᱡߺ߇↢ߓ ߚߚ߼ߣ⠨߃ࠄࠇࠆ㧚߹ߚ㧘ࡒ࡝ࡦࠣᤨ㑆߇

10

^ᤨ㑆 એ਄ߦߥࠆߣ㧘

Mg

2

Ni

ߩࡇ࡯ࠢ߇᷹ⷰߐࠇ㧘ൻว‛

߇ᒻᚑߒߚߎߣ߇ࠊ߆ࠆ㧚

⹜ᢱߩ⴫㕙᭴ㅧ

⹜ᢱ⴫㕙ߩ᭴ㅧࠍ᣿ࠄ߆ߦߔࠆߚ߼ߦ㧘

EDX

^ࠍ↪

޿ߡ⹜ᢱ⴫㕙ߩนⷞ⊛ߥ⹏ଔࠍ⹜ߺߚ㧚৻଀ߣߒߡ ࡒ࡝ࡦࠣᤨ㑆

10

ᤨ㑆ߩ⹜ᢱߩࡑ࠶ࡇࡦࠣ↹௝ࠍ Fig. 3ߦ␜ߔ㧚

ߎߎߢᥦ⦡㧘ኙ⦡ߪߘࠇߙࠇ

Mg

^㧘

Ni

^{⋧ᒰߔࠆ㧚}

Ni

ߩ⴫㕙ߦ

Mg

߇࿶ᑧߐࠇઃ⌕ߒߡ޿ࠆߎߣ߇ಽ߆ࠆ㧚 ൻว‛߇ᒻᚑߐࠇࠆ೨ߩઁߩࡒ࡝ࡦࠣᤨ㑆ߦ߅ߌࠆ

⹜ᢱߩࡑ࠶ࡇࡦࠣࠍ⷗ߡ߽ห᭽ߥ⚿ᨐ߇ᓧࠄࠇߡ޿

ࠆ㧚ߎߩේ࿃ߣߒߡߪ㊄ዻߩ⎬ߐߩ㆑޿ߢ޽ࠆߣ⠨

߃ࠄࠇࠆ㧚

Mg

^{ߪࡗࡦࠣ₸}

64.5GPa

^{ߢ㕖Ᏹߦエࠄ߆} ߊ㧘ᑧᕈ㧘ዷᕈߦን߻㊄ዻߢ޽ࠆ㧚ߘࠇߦᲧߴ

Ni

ߩࡗࡦࠣ₸ߪ

207GPa

^{ߢ⎬޿㧚ߘߩߚ߼㧘}

Ni

^ߩ⴫㕙 ߦ

Mg

߇࿶ᑧߐࠇ㧘ⶄวൻߐࠇߚߣ⠨߃ࠄࠇࠆ㧚߹

ߚ㧘ว㊄ߪ㊄ዻห჻ߩ࿕⋧⇇㕙ߢߒ߆ൻวߒ߃ߥ޿

ߎߣ߆ࠄ㧘

Mg

2

Ni

^ߪ

Mg

^㧘

Ni

^{ߩⶄว⇇㕙ߢ࿶❗ᔕജ} ࠍฃߌ↢ᚑߔࠆߣ⠨߃ࠄࠇࠆ㧚ߘߎߢ㧘ࡔࠞࡁࠤࡒ

ࠞ࡞ᴺߦࠃࠆ

Mg

2

Ni

^{ߩ↢ᚑࡕ࠺࡞ࠍ}Fig. 4ߦ␜ߔ㧚

᳓⚛ๆ⬿㊂ߩ᷹ቯ

ฦ ࡒ ࡝ ࡦ ࠣ ᤨ 㑆 ߦ ߅ ߌ ࠆ ⹜ ᢱ ߩ ᳓ ⚛ ๆ ⬿ ㊂ ࠍ

Fig. 5ߦ␜ߔ㧚᳓⚛ๆ⬿㊂ߪࡒ࡝ࡦࠣߩㅴⴕߦߣ߽

ߥ޿ᄙߊߥࠅ㧘ࡒ࡝ࡦࠣᤨ㑆

10h

^{ߢᦨᄢ୯ࠍߣࠅ㧘} ߘߩᓟ㧘ዋߥߊߥߞߡ޿ࠆ㧚

3.1

^{▵ߩ⚿ᨐߣᲧセߔࠆ} ߣว㊄ߢ޽ࠆ

Mg

2

Ni

ߩ↢ᚑߣหᤨ᳓⚛ๆ⬿㊂߇ૐਅ ߒߪߓ߼ߡ޿ࠆߎߣ߇ಽ߆ࠆ㧚ߎߩߎߣ߆ࠄ

Mg

2

Ni

ߩ↢ᚑߪ᳓⚛ๆ⬿ࠍᅹߍࠆ௛߈ࠍߒߡ޿ࠆߣ⠨߃ࠄ ࠇࠆ㧚ߟ߹ࠅ㧘

Mg

2

Ni

^ߪ

Mg

^ߣ

Ni

^{ߩ࿕⋧⇇㕙㑆ߦ↢}

ᚑߔࠆߎߣߢ㧘

Ni

ߦๆ⌕ߒ㧘⸃㔌ߒߚ᳓⚛ේሶ߇

Mg

^{ߦ៝ㅍߐࠇࠆߎߣࠍ}

Mg

2

Ni

^{ጀ߇㒖ኂߒߡ޿ࠆߣ}

Mg

Ni

Step1. Grinding and rolling External force from balls

Step2. Formation of alloys Mg2Ni Ni

Mg

Fig. 4. Formation process of Mg2Ni

(4)

0 0.2 0.4 0.6 0.8 1

0 10 20 30

Milling time [h]

360 370 380 390 400 410 420 430

0 10 20 30

Fig. 5. Hydrogen storage capacities with milling time.

⠨߃ࠄࠇࠆ㧚

᳓⚛᡼಴᷷ᐲߩ᷹ቯ

㜞࿶

DSC

ߦࠃࠅ᳞߼ߚฦࡒ࡝ࡦࠣᤨ㑆ߦ߅ߌࠆ

᳓⚛⸃㔌᷷ᐲࠍFig. 6ߦ␜ߔ㧚

ࡒ࡝ࡦࠣᤨ㑆߇

15

ᤨ㑆એ㒠ߦߥࠆߣ㧘᳓⚛᡼಴᷷ᐲ ߦ߶ߣࠎߤᄌൻ߇ߥߊߥߞߚ㧚ߎࠇߪ⹜ᢱ߇☳⎈㒢

⇇ߦ㆐ߒ㧘ᯏ᪾⊛ࠛࡀ࡞ࠡ࡯ߦࠃࠆᓸ☸ൻ߿ᱡߺ㧘

⚵ᚑᄌൻ߇ߘࠇએ㒠↢ߓߥ߆ߞߚߚ߼ߛߣ⠨߃ࠄࠇ ࠆ㧚߹ߚ㧘వ߶ߤߩ᳓⚛ๆ⬿ߩ႐วߣห᭽ߦ᳓⚛᡼

಴᷷ᐲߪว㊄ߢ޽ࠆ

Mg

2

Ni

ߩ↢ᚑߣߣ߽ߦ਄᣹ߒߡ

޿ࠆߎߣ߆ࠄ㧘᳓⚛᡼಴᷷ᐲߦߟ޿ߡ߽

Mg

^ߣ

Ni

ߩ⇇㕙ߩᓇ㗀ࠍฃߌࠆߎߣ߇⠨߃ࠄࠇࠆ㧚

MgH

2ߣ

Mg

2

NiH

4.2ߩ᳓⚛ൻࠛࡦ࠲࡞ࡇ࡯ߪߘࠇߙࠇ㧙

64.4

^㧘㧙

74.5 kJ/mol H

2ߢ޽ࠆߎߣ߆ࠄ᳓⚛ൻ‛ߣߒߡߪ ว㊄ൻᓟߩ߶߁߇቟ቯߢ޽ࠆߎߣ߆ࠄ߽᳓⚛᡼಴᷷

ᐲ߇਄᣹ߔࠆ㧚

0K ☸ሶᓘߩ㆑޿ߦࠃࠆ․ᕈᄌൻᲧセ

೨▵߹ߢߪᐔဋᓘ

10

^Ǵ

m

^ߩ

Ni

^{☸ሶ㧔࠾࡜ࠦᩣᑼ} ળ␠㧕ࠍ↪޿ߚ⚿ᨐߢ޽ࠆ㧚ജቇ⊛ߦ⎬޿

Ni

^ߪ

Mg

ߦኻߒߡ☳⎈ഥ೷ߩᓎഀ߽ᜬߟߚ߼㧘ߘߩ☸ሶᓘ߇ ⶄว᧚ᢱߩ᭴ㅧߦᄢ߈ߊଐሽߔࠆߣ⠨߃ࠄࠇࠆ㧘ߘ ߎߢ㧘ᐔဋᓘ

130nm

^ߩ

Ni

☸ሶ㧔ᣣᷡࠛࡦࠫ࠾ࠕ࡝

ࡦࠣᩣᑼળ␠㧕ߩᲧセࠍⴕ߁ߎߣߢ㧘

Ni

^{ߩ☸ሶᓘ߇}

⹜ᢱߩ᳓⚛ๆ᡼಴․ᕈߦ߅ࠃ߷ߔᓇ㗀ࠍᬌ⸛ߒߚ㧚 એ㒠㧘ᐔဋᓘ

130nm

^ߩ

Ni

^☸ሶߪ

nano Ni

^{ߣ⴫⸥ߔࠆ㧚}

߹ߚ㧘

Mg-nano Ni

^⹜ᢱߪ㧘

Mg-Ni

^{⹜ᢱߣห᧦ઙߢ૞}

⵾ߒߚ㧚

⚿᥏᭴ㅧᄌൻ߳ߩᓇ㗀

Mg-nanoNi

^♽ߩ

X

✢࿁᛬ࡄ࠲࡯ࡦߩᤨ㑆ᄌൻࠍ Fig. 7ߦ␜ߔ㧚

3.1

^{▵ߩ⚿ᨐߣห᭽ߦ}

Mg

^ߣ

Ni

^ߩࡇ

࡯ࠢᒝᐲߪᤨ㑆ߩ⚻ㆊߣߣ߽ߦᒙߊߥࠅ㧘ࡒ࡝ࡦࠣ

ᤨ㑆߇

10

^{ᤨ㑆ࠍ⿧߃ࠆߣ}

Mg

2

Ni

^{ߩࡇ࡯ࠢ߇಴⃻ߔ} ࠆߎߣ߇ࠊ߆ߞߚ㧚⚿ᨐࠍ⹦ߒߊᲧセߔࠆߣ㧘

nanoNi

ࠍ↪޿ߚ႐ว㧘ࡒ࡝ࡦࠣᤨ㑆

5

^{ᤨ㑆ߦ߅޿ߡૐⷺᐲ}

஥ߩ

Mg

ߩࡇ࡯ࠢ߇ᱷߞߡ޿ࠆߩߦኻߒߡ㧘

Ni

^ࠍ↪

޿ߚ႐วߪૐⷺᐲ஥ߩ

Mg

ߩࡇ࡯ࠢ߇ᶖᄬߒߡ޿ࠆ ߎߣ߇ಽ߆ࠆ㧚

᳓⚛ๆ᡼಴․ᕈߪ㧘࠽ࡁ⚿᥏ሶߩᒻᚑߦࠃࠅߘߩ

․ᕈߦᄢ߈ߥᄌൻ߇޽ࠆ^7-9)㧚ߘߎߢ㧘ฦࡒ࡝ࡦࠣᤨ

㑆ߦ߅ߌࠆ

Mg-Ni

^⹜ᢱߣ

Mg-nano Ni

^{⹜ᢱߩ⚿᥏ሶ} ࠨࠗ࠭ࠍ

Scherrer

^{ߩᑼࠍ↪޿ߡ▚಴ߒ}Fig. 8 ߦ␜ߔ㧚

Mg-Ni

⹜ᢱߪ⍴޿ࡒ࡝ࡦࠣᤨ㑆ߢ⚿᥏ሶࠨࠗ࠭߇ᄢ

᏷ߦዊߐߊߥߞߡ޿ࠆ㧚ߎࠇߦኻߒ㧘

Mg-nano Ni

^⹜ ᢱߪ㧘Ყセ⊛ࠁߞߊࠅߣ⚿᥏ሶࠨࠗ࠭߇ዊߐߊߥߞ ߡ޿ࠆ㧚ߟ߹ࠅ㧘ዊ☸ሶߩ

nanoNi

^{ࠍ↪޿ࠆߎߣߢ☳}

⎈ഥ೷ߣߒߡߩലᨐ߇ᷫዋߒ㧘ૐⷺᐲ஥ߩ

Mg

^ߩ⚿

᥏᭴ㅧ߇㐳ᤨ㑆⛽ᜬߐࠇߚߣ⠨߃ࠄࠇࠆ㧚 Fig. 6. Hydrogen desorption temperature with

milling times.

Hydrogen desorptiontemperature [

㷄

]Hydrogen storage capacity [wt%]

(5)

0 5 10 15 20 25

0 10 20 30

Mg-Ni Mg-nanoNi

0 0.2 0.4 0.6 0.8 1

0 15 30

Mg-Ni Mg-nanoNi

350 360 370 380 390 400 410 420 430

0 10 20 30

Mg-Ni Mg-nanoNi Fig. 7. X-ray diffraction patterns of Mg-nanoNi

with milling time.

᳓⚛ๆ⬿㊂߳ߩᓇ㗀

᳓⚛ๆ⬿㊂ߩ᷹ቯ⚿ᨐࠍFig. 9ߦ␜ߔ㧚ฦࡒ࡝ࡦ

ࠣᤨ㑆ߦ߅ߌࠆ

Mg-nanoNi

^{ߩ᳓⚛ๆ⬿㊂ߪ㧘}

Mg-Ni

ߩ᳓⚛ๆ⬿㊂ߩ⚿ᨐߣห᭽ߦ

Mg

2

Ni

^{߇↢ᚑߐࠇࠆߣ} หᤨߦૐਅߔࠆߎߣ߇⏕⹺ߐࠇߚ㧚ߎߩߎߣ߆ࠄ߽

Mg

^ߣ

Ni

ߣߩ⇇㕙߇᳓⚛ๆ⬿㊂ߦᄢ߈ߊᓇ㗀ࠍ෸߷

ߒߡ޿ࠆߎߣ߇᣿ࠄ߆ߣߥߞߚ㧚߹ߚ㧘⍴޿ࡒ࡝ࡦ

ࠣᤨ㑆ߢߪ

nanoNi

ࠍ↪޿ߚ႐วߩᣇ߇ዊߐ޿୯ߣ ߥߞߚ㧚ߎߩ᳓⚛ๆ⬿㊂ߩᄢዊ㑐ଥߪ㧘

Fig. 8

^ߦ␜

ߒߚ⚿᥏ሶࠨࠗ࠭ߩᄢዊ㑐ଥߣኻ⒓ߩᒻࠍߣࠆ㧚ߎ ߩߎߣ߆ࠄ㧘᳓⚛ๆ⬿ߦߪ

Mg

^ߣ

Ni

^{ߩ⇇㕙㧘߅ࠃ߮}

⚿᥏ሶࠨࠗ࠭߇ᷓߊ㑐ଥߒߡ޿ࠆ߽ߩߣ⠨߃ࠄࠇࠆ㧚

᳓⚛᡼಴᷷ᐲ߳ߩᓇ㗀

᳓⚛᡼಴᷷ᐲߩᲧセ⚿ᨐࠍFig. 10ߦ␜ߔ㧚

᳓⚛᡼಴᷷ᐲߪ

nanoNi

ࠍ↪޿ߚ႐วߦᄢ߈ߊૐਅ ߒߡ޿ࠆߎߣ߇ಽ߆ࠆ㧚ߎࠇߪ

Ni

^{ߩ☸ሶᓘ߇ዊߐߊ} ߥࠆߎߣߢ㧘

Mg-Ni

⇇㕙Ⓧ߇ᄢ߈ߊߥࠅ᡼಴ߒ߿ߔ

Intensity [-]

2ǰ[degree]

㬍

䂦

䂦䂦

䂦

Mg Ni

㬍MgO ^䂦Mg₂Ni

Intensity [-]

2ǰ[degree]

㬍

䂦

䂦䂦

䂦

Mg Ni

㬍MgO ^䂦Mg₂Ni

Fig. 8. Comparison of the average crystallite sizes with milling time between Mg-Ni and Mg-nanoNi.

Average crystallite sizes [nm]

Fig. 9. Comparison of hydrogen storage capacities between Mg-Ni and Mg-nanoNi with milling time.

Hydrogen desorptiontemperature [

㷄

]

Fig. 10. Comparison of hydrogen desorption temperature between Mg-Ni and Mg-nanoNi with milling time.

Hydrogen storage capacity [wt%]

(6)

ߊߥߞߚߎߣߣ㧘

Mg

߆ࠄฃߌขߞߚ᳓⚛ේሶ߇

Ni

ߩౝㇱࠍ᜛ᢔߒᄢ᳇ߦ᡼಴ߐࠇࠆ߹ߢߩⴕ〝㐳߇⍴

ߊߥߞߚߚ߼ߛߣ⠨߃ࠄࠇࠆ㧚

߹ߣ߼

ᧄ⎇ⓥߢߪ㧘ታ↪ൻ᳓⚛⾂⬿᧚ᢱߩ㐿⊒ߩᜰ㊎ࠍ

␜ߔߚ߼ߦ㧘ࡔࠞࡁࠤࡒࠞ࡞ᴺࠍ↪޿ߡ૞⵾ߒߚ

Mg

^ߣ

Ni

ߩⶄว᧚ᢱߩ᭴ㅧ߇᳓⚛ๆ⬿᡼಴․ᕈߦਈ ߃ࠆᓇ㗀ࠍታ㛎⊛ᣇᴺߦࠃࠅᬌ⸛ߒߚ㧚

ࡔࠞࡁࠤࡒࠞ࡞ᴺߦࠃࠅ૞⵾ߐࠇߚⶄว᧚ᢱߪ㧘

㊄ዻߩ⎬ߐߩ㑐ଥ߆ࠄ

Ni

^⴫㕙ߦ

Mg

^{߇࿶ᑧߒߚ᭴ㅧ} ࠍߣࠆߎߣ߇⏕⹺ߐࠇ㧘ว㊄ߩ

Mg

2

Ni

^ߪ

Mg

^ߣ

Ni

ߣߩ࿕⋧⇇㕙ߦ↢ᚑߔࠆߎߣ߇ಽ߆ߞߚ㧚᳓⚛ๆ⬿

㊂ߩૐਅ߿᳓⚛᡼಴᷷ᐲߩ਄᣹߇

Mg

2

Ni

^{ߩ↢ᚑߣห}

ᤨߦ⿠ߎࠆߎߣ߆ࠄ㧘

Mg

2

Ni

^߇

Mg-Ni

^{㑆ߦሽ࿷ߔࠆ} ߎߣߢ᳓⚛ๆ⬿࡮᡼಴ㆊ⒟ߦ߅޿ߡ

Mg-Ni

^㑆ߢߩ᳓

⚛ߩ᝼ฃ߇ᅹߍࠄࠇߡ޿ࠆߣ⠨߃ࠄࠇࠆ㧚߹ߚ㧘ว

㊄ൻᓟߩ᳓⚛ൻ‛ߩ቟ቯᕈߪว㊄ൻ೨ࠃࠅ߽㜞޿ߚ

߼㧘᳓⚛᡼಴᷷ᐲߪ

Mg

2

Ni

߇↢ᚑߔࠆߎߣߢ਄᣹ߒ ߡߒ߹߁ߣᕁࠊࠇࠆ㧚ߎࠇࠄߩߎߣ߆ࠄ

Mg

^ߣ

Ni

ߩታ↪ൻ᳓⚛⾂⬿᧚ᢱߩ㐿⊒ߩߚ߼ߦߪ᳓⚛᝼ฃߩ ᅹߍߣߥࠆ

Mg

2

Ni

^{ࠍ↢ᚑߖߕߦ}

Mg

^ߣ

Ni

^ߩ⇇㕙ࠍ

޿߆ߦᄙߊ૞ࠆߎߣ߇ߢ߈ࠆ߆ߣ޿߁ߎߣߦߥࠆ㧚

߹ߚ㧘

Ni

☸ሶᓘߩ㆑޿ߦࠃࠆ․ᕈᲧセߩታ㛎߆ࠄ ߪ☸ሶᓘߦᄌൻࠍਈ߃ߡ߽㧘᳓⚛ๆ᡼಴․ᕈߪว㊄ ߩ↢ᚑߦߣ߽ߥߞߡૐਅߔࠆߎߣ߇⏕⹺ߐࠇ㧘

Mg

ߣ

Ni

ߩ⇇㕙ߩ₪ᓧ߇㜞ᯏ⢻ൻߦᭂ߼ߡ㊀ⷐߢ޽ࠆ ߎߣ߇⏕⹺ߢ߈ߚ㧚߹ߚ㧘

Ni

^{ߩ☸ሶᓘࠍᄌൻߐߖࠆ} ߎߣߢᓧࠄࠇࠆⴣ⓭ࠛࡀ࡞ࠡ࡯ࠍᄌൻߐߖࠆߎߣ߇ น⢻ߢ޽ࠆߎߣ߽ಽ߆ߞߚ㧚ⴣ⓭ࠛࡀ࡞ࠡ࡯ߪ⹜ᢱ ߩ⚿᥏ሶࠨࠗ࠭ߦᄢ߈ߊᓇ㗀ࠍ෸߷ߒ㧘ߎߩ⚿᥏ሶ ࠨࠗ࠭ߪ᳓⚛ๆ⬿㊂ߦᷓߊᓇ㗀ߒߡ޿ࠆߣ⠨߃ࠄࠇ ࠆ㧚

એ਄ߩߎߣ߆ࠄ㧘

Mg

^ߣ

Ni

^{ߣߩ⇇㕙ߩ೙ᓮߣ㧘}

Ni

ߩ☸ሶᓘࠍᄌൻߐߖࠆ╬ߩᠲ૞ࠍ↪޿ߡ⚿᥏ሶࠨࠗ

࠭ࠍ೙ᓮߔࠆߎߣߦࠃࠅ㧘᦭↪ߥ᳓⚛⾂⬿᧚ᢱߩ㐿

⊒߇น⢻ߦߥࠆߣ⠨߃ࠄࠇࠆ㧚

ᧄ⎇ⓥߢ૶↪ߒߚ

nanoNi

^{☸ሶߪᣣᷡࠛࡦࠫ࠾ࠕ}

࡝ࡦࠣᩣᑼળ␠߆ࠄឭଏߒߡ㗂޿ߚ߽ߩߢ޽ࠆ㧚ߎ

ߎߦᷓ⻢↳ߒ਄ߍࠆ㧚߹ߚ㧘ᧄ⎇ⓥߩ㧝ㇱߪᢥㇱ⑼ ቇ⋭ቇⴚࡈࡠࡦ࠹ࠖࠕផㅴ੐ᬺޟᰴ਎ઍ࠯ࡠࠛࡒ࠶

࡚ࠪࡦࠛࡀ࡞ࠡ࡯ᄌ឵ࠪࠬ࠹ࡓޠߥࠄ߮ߦ⑼ቇ⎇ⓥ

⾌⵬ഥ㊄㧔ၮ⋚⎇ⓥ

(c)

^⺖㗴⇟ภ

18560726

^{㧕ߩᡰេࠍ} ฃߌߚ㧚ߎߎߦ⻢ᗧࠍ⴫ߔࠆ㧚

ෳ⠨ᢥ₂

1) ᄢⷺᵏ┨, ᣂ ᳓⚛ๆ⬿ว㊄㧙ߘߩ‛ᕈߣᔕ↪㧙㧘 (ᩣᑼળ␠ࠕࠣࡀᛛⴚ࠮ࡦ࠲࡯, ᧲੩ㇺ, 1993)㧚 2) S. Bliznakov, N. Drenchev㧘 ̌Electrochemical properties

of nanocrystalline Mg2Ni-type alloys prepared by mechanical alloying̍, Journal of Alloys and Compounds, 404-406, 682-686, (2005)㧚

3) ᛬⨃ᘕ৻,̌ᣂߚߥࡑࠣࡀࠪ࠙ࡓ♽᳓⚛ൻ‛ߩត⚝̍, ᣣᧄ㊄ዻቇળળႎ, 310㧘817-823㧘(2000)㧚

4) ᢧ⮮ᢥ⦟, ☳⎈, 39, 24, (2000)㧚

5) ↰᧛⧷㓶, ᳓⚛ๆ⬿ว㊄㨪ၮ␆߆ࠄᦨవ┵ᛛⴚ߹ߢ 㨪, (ࠛ࠿࡮࠹ࠖ࡯࡮ࠛࠬ, ᧲੩ㇺ, 1998)㧚

6) ⷏ኅᱜ⿠, ̌᳓⚛ๆ⬿ว㊄ߩ࿶ജ㧙⚵ᚑ╬᷷✢(PCT

✢)ߩ᷹ቯᣇᴺ̍, JIS, (1991)㧚

7) E. Akiba, H. Enoki, Y. Nakamura, ̌Nano scale structure such as nano-size crystallites and defects can be found in conventional hydrogen absorbing alloys̍, Materials Science and Engineering, B108, 60-66㧘(2004)㧚

8) N. Hanada, T. Ichikawa, S. Orimo, ̌Correlation between hydrogen storage properties and structural characteristics in mechanically milled magnesium hydride MgH2̍, Journal of Alloys and Compounds, 366, 269-273, (2004)㧚 9) H. Imamura, Kazuo Masanari, ̌High hydrogen storage

capacity of nanosized magnesium synthesized by high energy ball-milling̍, Journal of Alloys and Compounds, 386, 211-216, (2005)㧚

Development of Mg-Ni Composite Hydrogen Storage by Mechano-Chemical Method