JP2003321215A - Graphite-based hydrogen-occluding material and method for producing the same - Google Patents

Graphite-based hydrogen-occluding material and method for producing the same

Info

Publication number
JP2003321215A
JP2003321215A JP2002126296A JP2002126296A JP2003321215A JP 2003321215 A JP2003321215 A JP 2003321215A JP 2002126296 A JP2002126296 A JP 2002126296A JP 2002126296 A JP2002126296 A JP 2002126296A JP 2003321215 A JP2003321215 A JP 2003321215A
Authority
JP
Japan
Prior art keywords
graphite
hydrogen storage
hydrogen
aggregate
based hydrogen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2002126296A
Other languages
Japanese (ja)
Inventor
Minoru Shirohige
稔 白髭
Junichi Iida
淳一 飯田
Hitoshi Ito
仁 伊藤
Junji Katamura
淳二 片村
Mikio Kawai
幹夫 川合
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Resonac Corp
Original Assignee
Hitachi Powdered Metals Co Ltd
Nissan Motor Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Powdered Metals Co Ltd, Nissan Motor Co Ltd filed Critical Hitachi Powdered Metals Co Ltd
Priority to JP2002126296A priority Critical patent/JP2003321215A/en
Publication of JP2003321215A publication Critical patent/JP2003321215A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/32Hydrogen storage

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a graphite-based hydrogen-occluding material which is lightweight, can be repeatedly used and easily produced, and to achieve a method for producing the same. <P>SOLUTION: The graphite-based hydrogen-occluding material comprises a graphite aggregate in which nanostructured graphite with crystallites having a size of 1-40 nm is aggregated. The graphite aggregate has an average particle size of 1-60 μm, a specific surface area of 300 m<SP>2</SP>/g or more, an average pore radius of 5.5 nm or less, and an interlayer distance of 0.3360-0.3385 nm. <P>COPYRIGHT: (C)2004,JPO

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明が属する技術分野】この発明は、黒鉛系の水素吸
蔵材料及びその製造方法に関するものである。なお、本
明細書において、Ni、Pt、Pd、K、Li等は元素
記号である。
TECHNICAL FIELD The present invention relates to a graphite-based hydrogen storage material and a method for producing the same. In the present specification, Ni, Pt, Pd, K, Li and the like are element symbols.

【0002】[0002]

【従来の技術】固体高分子型燃料電池の開発競争が活発
に繰り広げられる中、実用化のためコストが低く、特に
輸送用機器への車載を検討されているものは軽量で、吸
蔵密度が高く、水素の充填、放出速度の速い水素吸蔵材
料を用いた水素貯蔵法の開発が望まれている。現在、水
素を輸送用機器に車載する方法としては、高圧ガス、液
体水素、水素吸蔵合金、炭素系材料の4種類の方法が提
案されている。ここで、高圧ガスを車に搭載することは
天然ガス(メタン)自動車で実用化されており、200
気圧まで圧縮されボンベに蓄えられる。したがって、燃
料電池自動車に水素ボンベを用いることは本質的に問題
なく、水素貯蔵量を増やすため350気圧にし充填量を
増やすことが検討されている。しかし、ボンベは高圧に
耐えるために厚肉化され重量が増大するという問題を抱
えている。次に、液体水素による輸送貯蔵では、水素の
沸点(−253℃)より低温にすることで液化水素を製
造できる。液化水素は、気体と比べて体積が約800分
の1であるため水素の優れた貯蔵方法である。しかし、
水素の気化熱が小さいことに起因する気化(ボイルオ
フ)、超低温に耐える容器を要する点などが課題とな
る。これに対し、水素吸蔵合金による輸送貯蔵として
は、Ni−水素電池にも使用されている希土類系合金の
LaNi が代表的である。この材料の水素吸蔵量は
1.4重量%程度である。また、最近はTiとVを基本
とした合金中で体心立方(BCC)構造を持つ固溶体相
が水素吸蔵性に優れていることがわかり、検討が進めら
れている。その一方で、近年、炭素系材料を用いた水素
吸蔵の研究が盛んに行われている。炭素系材料として
は、活性炭、グラファイト層間化合物、カーボンナノチ
ューブ(CNT)、グラファイトナノファイバー(GN
F)、フラーレン類などであり、常温での吸蔵・放出特
性、製造コスト、量産性や収率などに課題を有している
が、その課題を克服すべく更なる検討が進められてい
る。具体的には以下のとおりである。
2. Description of the Related Art While development competition of polymer electrolyte fuel cells is actively under way, the cost is low for practical use. Especially, those that are considered to be mounted on transportation equipment are lightweight and have high storage density. It is desired to develop a hydrogen storage method using a hydrogen storage material having a high hydrogen filling and releasing rate. At present, four types of methods have been proposed as a method for mounting hydrogen on a transportation device, including high-pressure gas, liquid hydrogen, a hydrogen storage alloy, and a carbon-based material. Here, installing high-pressure gas in a vehicle has been put to practical use in a natural gas (methane) vehicle.
It is compressed to atmospheric pressure and stored in a cylinder. Therefore, using a hydrogen cylinder in a fuel cell vehicle is essentially no problem, and it has been considered to increase the filling amount to 350 atm in order to increase the hydrogen storage amount. However, the cylinder has a problem that it is thickened to withstand high pressure and its weight increases. Next, in transport storage using liquid hydrogen, liquefied hydrogen can be produced by lowering the temperature below the boiling point of hydrogen (−253 ° C.). Liquefied hydrogen is an excellent method for storing hydrogen because it has a volume of about 1/800 that of gas. But,
There are problems such as vaporization (boil-off) due to the small heat of vaporization of hydrogen, and the need for a container that can withstand ultra-low temperatures. On the other hand, LaNi 5, which is a rare earth alloy also used in Ni-hydrogen batteries, is typical for transportation and storage by hydrogen storage alloys. The hydrogen storage capacity of this material is approximately 1.4% by weight. Further, recently, in an alloy based on Ti and V, it has been found that a solid solution phase having a body-centered cubic (BCC) structure has excellent hydrogen storage properties, and studies have been conducted. On the other hand, in recent years, research on hydrogen storage using a carbon-based material has been actively conducted. Carbon-based materials include activated carbon, graphite intercalation compounds, carbon nanotubes (CNT), graphite nanofibers (GN).
F), fullerenes, and the like, which have problems in storage / release characteristics at room temperature, manufacturing cost, mass productivity, yield, etc., but further studies are being made to overcome these problems. Specifically, it is as follows.

【0003】炭素系材料のうち、CNTを用いる水素吸
蔵法は最も注目され、水素吸蔵合金の吸蔵能よりも優れ
た4〜10wt%前後の吸蔵能達成の報告もなされてい
る。単層CNTは、炭素原子が六角網目状に配列した一
枚のグラフェンシートが丸まった直径が数〜数十nmの
円筒状であり、それらがバンドル状(束状)になった構
造を取ることが多く、チューブ内部あるいはチューブ間
は強い物理ポテンシャルが作用し、そこに多量の水素分
子が物理吸着するとされている。多層CNTは、グラフ
ェンシートが同心円状に等間隔に多層に重なったもの
で、チューブ壁が多層であるため水素分子と接触する表
面炭素原子の割合は少なくなるが、グラフェンシート間
隔に水素が進入すれば高い水素吸蔵機能が期待できると
されている。また、多層CNTの合成法の発達により配
向度が高いものも合成され、その結果、高い水素吸蔵量
の報告がなされている。なお、特開2001−2201
01号公報には、CNT、GNFおよび活性炭などの細
孔を有する炭素材料に水素を吸蔵させる技術が提案され
ている。しかし、一般的にナノチュープでは、高い水素
吸蔵は液体窒素付近の低温で達成可能であり、常温での
吸蔵能は0.2〜0.4wt%と低く、又、実用化のた
めには大幅なコスト低減、生産能力の向上など課題が多
い。特開2001−302224号公報では、水素雰囲
気中で黒鉛を機械的に粉砕し、ナノ構造化された黒鉛に
水素を貯蔵させる提案もなされ、7.4wt%の水素放
出が確認されている。水素雰囲気中で黒鉛を粉砕するこ
とで、水素を共有結合、また、共有結合なしで黒鉛粒子
内に貯蔵することを特徴とするものであり、大きな吸蔵
性が確認されている。この技術は、文献(炭素 TAN
SO 2001「No.200」pp261〜268)
にも詳述されている。一例を挙げると、『ナノ構造化グ
ラファイト内部の水素量は、ミリング処理時間の増加、
すなわち欠陥構造の発展に伴って著しく増加し、80時
間後の水素量は7.4wt%にも達することがわかる。
80時間のミリング処理後の比表面積はわずかに10m
/gのオーダーであり、試料表面での物理吸着量は極
めて少ない。また、質量数2の水素分子の昇温脱離スペ
クトルは、およそ600K、950Kで始まる2つピー
クを示した。』など、興味深い解析がなされている。し
かし、実際の使用に際しては、水素放出温度の低温化と
サイクル性(繰り返しの使用)の確保が必要である。水
素雰囲気での水素吸蔵性は、粉砕によって生じるダング
リングボンド、構造欠陥が推進力になっているとされ、
水素の存在位置は、中性子回析実験より黒鉛のダングリ
ングボンドと結合している水素、もう一つは黒鉛層間に
位置する水素であることが報告されている。従って、一
度加熱し水素を放出させた材料に水素を入れる場合、加
圧では水素がほとんど入らず(0.2wt%)、また、
再度水素雰囲気で粉砕するにしても、黒鉛の結晶子が小
さくなっており、アモルファス化した状態であるため、
水素の吸蔵がほとんど認められないことが問題である。
従って、水素雰囲気中での粉砕では、放出温度が高いこ
とと繰り返しの使用ができないことが問題である。
Among the carbonaceous materials, the hydrogen storage method using CNT has received the most attention, and it has been reported that the storage capacity of about 4 to 10 wt%, which is superior to the storage capacity of hydrogen storage alloys, is achieved. The single-walled CNT has a structure in which a single graphene sheet in which carbon atoms are arranged in a hexagonal mesh is a cylindrical shape having a rolled diameter of several to several tens of nm, and they are bundled (bundle-shaped). It is said that a strong physical potential acts inside or between the tubes, and a large amount of hydrogen molecules are physically adsorbed there. Multilayer CNTs are graphene sheets that are concentrically stacked in multiple layers at equal intervals. Since the tube wall is multilayer, the proportion of surface carbon atoms that come into contact with hydrogen molecules is small, but hydrogen enters the graphene sheet spacing. It is said that a high hydrogen storage function can be expected. Further, due to the development of the synthesis method of multi-walled CNT, those having a high degree of orientation have been synthesized, and as a result, a high hydrogen storage amount has been reported. Incidentally, JP-A-2001-2201
No. 01 publication proposes a technique of storing hydrogen in a carbon material having pores such as CNT, GNF and activated carbon. However, in general, in nanotubes, high hydrogen storage can be achieved at a low temperature near liquid nitrogen, and the storage capacity at room temperature is as low as 0.2 to 0.4 wt%, and it is significantly large for practical use. There are many issues such as cost reduction and improvement of production capacity. Japanese Patent Laid-Open No. 2001-302224 proposes to mechanically pulverize graphite in a hydrogen atmosphere to store hydrogen in the nanostructured graphite, and confirms that hydrogen is released at 7.4 wt%. It is characterized by crushing graphite in a hydrogen atmosphere to store hydrogen in the graphite particles covalently or non-covalently, and a large storage property has been confirmed. This technology is based on the literature (Carbon TAN
SO 2001 "No. 200" pp261-268)
Are also detailed. To give an example, “The amount of hydrogen in the nanostructured graphite increases with the milling time,
That is, it can be seen that the hydrogen content remarkably increases with the development of the defect structure, and the hydrogen content after 80 hours reaches 7.4 wt%.
Specific surface area is only 10m after milling for 80 hours
It is on the order of 2 / g, and the physical adsorption amount on the sample surface is extremely small. Further, the thermal desorption spectrum of the hydrogen molecule having a mass number of 2 showed two peaks starting at approximately 600K and 950K. , Etc., an interesting analysis is made. However, in actual use, it is necessary to lower the hydrogen release temperature and ensure cycleability (repeated use). It is said that hydrogen storage in a hydrogen atmosphere is driven by dangling bonds and structural defects caused by pulverization.
It has been reported from the neutron diffraction experiment that hydrogen is located in the hydrogen bonded to the dangling bond of graphite, and the other is located between the graphite layers. Therefore, when hydrogen is added to a material that has been heated and released, hydrogen hardly enters under pressure (0.2 wt%).
Even if it is pulverized again in a hydrogen atmosphere, the crystallites of graphite are small, and since it is in an amorphous state,
The problem is that hydrogen storage is hardly observed.
Therefore, in the pulverization in a hydrogen atmosphere, there are problems that the release temperature is high and it cannot be repeatedly used.

【0004】[0004]

【発明が解決しようとする課題】以上のような炭素系材
料は、貯蔵・放出条件によっては水素貯蔵合金よりも高
い水素吸蔵能を示すが、放出温度が高かったり、吸蔵メ
カニズム上、繰り返しの使用ができなかったり、製法
上、大量生産ができない等問題が多い。そこで、この発
明は、大量の水素を効率的に吸蔵させることができ、軽
量で、繰り返し使用でき、作製も容易な黒鉛系水素吸蔵
材料及びその製造方法を提供することを目的としたもの
である。
The above-mentioned carbon-based materials have higher hydrogen storage capacity than hydrogen storage alloys depending on the storage and release conditions, but they have a high release temperature and are repeatedly used due to the storage mechanism. There are many problems such as not being able to do it, and being unable to mass-produce due to the manufacturing method. Therefore, the present invention is intended to provide a graphite-based hydrogen storage material that can efficiently store a large amount of hydrogen, is lightweight, can be repeatedly used, and is easy to manufacture, and a method for producing the same. .

【0005】[0005]

【課題を解決するための手段】本発明者らは、上記の目
的を達成するため、原料としては入手・製造が容易な黒
鉛を用い、黒鉛の構造を如何に利用するか、黒鉛の表面
活性を如何に利用するかの点から鋭意研究を重ねた結
果、水素吸蔵量の多い黒鉛系水素吸蔵材料として、黒鉛
の結晶子間隔の活用、黒鉛の層間の活用、細孔構造の活
用、これらを最大まで引き出す上で、ナノ構造化した黒
鉛が凝集した構造で平均粒径1〜60μmにすべきであ
ることが分かり、この発明に至った。すなわち、発明の
黒鉛系水素吸蔵材料は、結晶子の大きさが1〜40nm
のナノ構造化した黒鉛が凝集した黒鉛凝集体からなり、
該黒鉛凝集体の平均粒径が1〜60μmであることを特
徴とし、これにより高い水素吸蔵性を達成したものであ
る。
[Means for Solving the Problems] In order to achieve the above-mentioned objects, the present inventors have used graphite, which is easy to obtain and manufacture, as a raw material, how to utilize the structure of graphite, and the surface activity of graphite. As a result of earnest research from the viewpoint of how to use, as a graphite-based hydrogen storage material with a large amount of hydrogen storage, utilization of graphite crystallite spacing, utilization of graphite layers, utilization of pore structure, It was found that the average particle diameter should be 1 to 60 μm in a structure in which nanostructured graphite is agglomerated in order to bring out to the maximum, and the present invention was completed. That is, the graphite-based hydrogen storage material of the invention has a crystallite size of 1 to 40 nm.
Consisting of agglomerated graphite aggregates of nanostructured graphite of
The graphite aggregates are characterized by having an average particle size of 1 to 60 μm, whereby a high hydrogen storage property is achieved.

【0006】以上の発明は請求項2〜4のようにより詳
細に特定可能である。まず、発明の黒鉛凝集体におい
て、比表面積が300m /g以上、平均細孔径が
5.5nm以下、黒鉛の層間距離が0.336〜0.3
385nmである。また、黒鉛凝集体の半径5.0nm
以下の細孔容積が0.3cm/g以上であることが、
水素吸蔵材料として重要である。さらに、黒鉛凝集体の
嵩密度を0.5〜1.5g/cmまで上昇させ、単位
容積当たりの吸蔵量を増やすことが可能となる。これら
に加え、請求項5に特定したごとく黒鉛凝集体の中にP
t、Pd、Ni、K、Li、Ti、V、Cr、Mn、F
e、Co、Zr、Nbの何れか1種以上を含有すること
で、単位重量当たりの水素吸蔵量を増加させることが可
能であり、好ましい態様である。そして、以上の黒鉛系
水素吸蔵材料は、請求項6や7の製造方法により容易に
作製できるという利点を有している。
The above inventions can be specified in more detail as in claims 2 to 4. First, in the graphite aggregate of the invention, the specific surface area is 300 m 2 / g or more, the average pore diameter is 5.5 nm or less, and the graphite interlayer distance is 0.336 to 0.3.
It is 385 nm. Also, the radius of the graphite aggregate is 5.0 nm
The following pore volume is 0.3 cm 3 / g or more,
It is important as a hydrogen storage material. Furthermore, it is possible to increase the bulk density of the graphite aggregate to 0.5 to 1.5 g / cm 3 and increase the storage amount per unit volume. In addition to these, P is contained in the graphite aggregate as specified in claim 5.
t, Pd, Ni, K, Li, Ti, V, Cr, Mn, F
By containing any one or more of e, Co, Zr, and Nb, the hydrogen storage amount per unit weight can be increased, which is a preferred embodiment. The graphite-based hydrogen storage material described above has the advantage that it can be easily manufactured by the manufacturing method according to the sixth or seventh aspect.

【0007】[0007]

【発明の実施の形態】以上の発明の黒鉛系水素吸蔵材料
及び製造方法について説明する。発明の第1の特徴は、
黒鉛系水素吸蔵材料として、結晶子の大きさが1〜40
nmのナノ構造化した黒鉛が凝集した黒鉛凝集体からな
り、該黒鉛凝集体の平均粒径が1〜60μmであること
である。具体的には、結晶性の良い黒鉛に粉砕処理等を
施すことで形成される結晶子の大きさが1〜40nmの
ナノ構造化した黒鉛を、平均粒径1〜60μmの範囲で
凝集した粒子にすることにより、ナノ構造化した黒鉛結
晶子内、黒鉛凝集体を形成する黒鉛結晶子間隙に水素が
良好に吸着し吸蔵しやすくなる。
BEST MODE FOR CARRYING OUT THE INVENTION The graphite-based hydrogen storage material and the manufacturing method of the above invention will be described. The first feature of the invention is that
The graphite-based hydrogen storage material has a crystallite size of 1 to 40.
nm nanostructured graphite is agglomerated to form an aggregate of graphite, and the average particle size of the graphite aggregate is 1 to 60 μm. Specifically, particles obtained by aggregating nanostructured graphite having a crystallite size of 1 to 40 nm formed by subjecting graphite having good crystallinity to crushing or the like in an average particle size range of 1 to 60 μm. By this, hydrogen is favorably adsorbed in the nanostructured graphite crystallites and in the graphite crystallite gaps forming the graphite aggregates, and hydrogen is easily occluded.

【0008】詳述すれば、ナノ構造化した黒鉛結晶子の
黒鉛凝集体の作製には結晶性の発達した結晶子の大きさ
が20nm以上の黒鉛を用いることが望ましい。また、
より最適条件は100nm以上の結晶子を持つ黒鉛が良
好であり、粉砕により結晶子の大きさを1〜40nmま
で小さくすると同時に、結晶粒子が適度に凝集した構造
を作ることが重要である。具体的には、例えば、原料黒
鉛として黒鉛粒子が平均粒径1〜100μmの黒鉛を用
いて、乾式で粉砕、凝集を進めるが、その際、採用粉砕
機と粉砕条件を工夫して発明で特定した平均粒径の黒鉛
凝集体として調製することである。結晶子の大きさが2
0nm以上の黒鉛原料としては、鱗片状黒鉛、鱗状黒
鉛、土状黒鉛などの天然黒鉛、コークスなどを焼成して
製造する人造黒鉛、メソフェーズピッチを原料として焼
成するメソフェーズピッチ系黒鉛など、結晶性の発達し
た黒鉛が使用できる。
More specifically, it is desirable to use graphite having a crystallite size with developed crystallinity of 20 nm or more to prepare a graphite aggregate of nanostructured graphite crystallites. Also,
The more optimal condition is that graphite having a crystallite of 100 nm or more is preferable, and it is important to reduce the size of the crystallite to 1 to 40 nm by pulverization and at the same time make a structure in which crystal particles are appropriately aggregated. Specifically, for example, graphite having an average particle size of 1 to 100 μm is used as raw material graphite, and dry pulverization and agglomeration are promoted. It is to prepare it as a graphite aggregate of the average particle size. Crystallite size is 2
Examples of the graphite raw material of 0 nm or more include natural graphite such as flake graphite, flake graphite, and earth graphite, artificial graphite produced by firing coke, and mesophase pitch-based graphite obtained by firing mesophase pitch as a raw material. Developed graphite can be used.

【0009】発明の第2の特徴は、この黒鉛凝集体の比
表面積が、300m /g以上、平均細孔径が5.5
nm以下、層間距離が0.3360〜0.3385nm
であり、第3の特徴としては前記黒鉛凝集体の細孔半径
5.0nm以下の細孔容積が0.3cm/g以上であ
り、これらは共に水素吸蔵量を多くするために重要であ
る。試験からは、粉砕が進むに伴って、ナノ粒子化が進
み、比表面積、細孔容積が増加し、平均細孔半径が減少
する傾向となるが、更に粉砕を進めるとナノ粒子の凝集
が促進し、比表面積、細孔容積が減少し、平均細孔半径
が増加する傾向が認められた。また、水素吸蔵量が多
く、サイクル特性の良好な黒鉛系水素吸蔵材料として
は、粉砕を適度にコントロールすることが不可欠であ
り、平均細孔半径として5.5nm以下のミクロ〜メソ
孔からなる細孔を有し、その容積が0.3cm/g以
上、比表面積が300m/g以上であることが好まし
いとの結果を得た。さらに、粉砕により(002)の面
間隔(層間距離)も増加するが、層間距離を0.336
0〜0.3385nmとすることにより、水素吸蔵量を
増大できることが判明した。この点は、粉砕を進めるこ
とに従い層間距離の増加が認められるが、層間距離0.
3385nmを超えると、結晶性が悪くなり、アモルフ
ァス化が進み、水素吸蔵量が減少することが認められ
た。以上のように、この発明は、水素吸蔵量の多い黒鉛
系水素吸蔵材料として、黒鉛の結晶子間隔の活用、黒鉛
の層間の活用、細孔構造の活用が優劣を決め、これらを
有効に活用できるようにする上で、ナノ構造化した黒鉛
が凝集した構造で平均粒径1〜60μmになっているこ
とが最も好ましいことを見出し、完成されたものであ
る。
The second feature of the invention is that the graphite aggregate has a specific surface area of 300 m 2 / g or more and an average pore diameter of 5.5.
nm or less, interlayer distance is 0.3360 to 0.3385 nm
The third characteristic is that the pore volume of the graphite aggregate having a pore radius of 5.0 nm or less is 0.3 cm 3 / g or more, both of which are important for increasing the hydrogen storage capacity. . From the test, as the pulverization progresses, the particles become nanoparticle, the specific surface area and pore volume increase, and the average pore radius tends to decrease, but further pulverization promotes the aggregation of nanoparticles. However, the specific surface area and pore volume decreased, and the average pore radius tended to increase. Further, as a graphite-based hydrogen storage material having a large hydrogen storage capacity and good cycle characteristics, it is indispensable to appropriately control pulverization, and it is possible to obtain fine pores composed of micro to mesopores having an average pore radius of 5.5 nm or less. It was obtained that the pores are preferable, the volume thereof is 0.3 cm 3 / g or more, and the specific surface area thereof is 300 m 2 / g or more. Further, the crushing also increases the (002) plane distance (interlayer distance), but the interlayer distance is 0.336.
It was found that the hydrogen storage amount can be increased by setting it to 0 to 0.3385 nm. At this point, an increase in the interlayer distance is recognized as the pulverization proceeds, but the interlayer distance is 0.
It was confirmed that when it exceeds 3385 nm, the crystallinity deteriorates, the amorphization progresses, and the hydrogen storage amount decreases. As described above, the present invention, as a graphite-based hydrogen storage material with a large hydrogen storage capacity, determines the superiority or inferiority of utilization of the crystallite spacing of graphite, utilization of the layers of graphite, and utilization of the pore structure, and these are effectively utilized. In order to make it possible, it was found that it is most preferable that the nanostructured graphite has an agglomerated structure and an average particle diameter of 1 to 60 μm, and thus it has been completed.

【0010】発明の第5の特徴は、前記黒鉛凝集体の嵩
密度を0.5〜1.5g/cmとすることにより、体
積当たりの水素吸蔵量が増加し、水素吸蔵用炭素材料の
容積を減らすことが可能になる。これに関し、粉砕で得
られる水素吸蔵材料の嵩密度は、一般には0.1〜0.
3g/cmあるが、湿式や乾式の造粒装置を用いるこ
とで1.2g/cm程度まで嵩密度を向上させること
が可能であり、また、プレス機やロールプレスを利用し
た圧縮により更に嵩密度を上げることができる。しか
し、嵩密度を1.6g/cmまで増加させると、造粒
品または成型品の表面の空隙がほとんどなくなり、水素
吸蔵量が大幅に減少する。したがって、前記黒鉛凝集体
を嵩密度1.5g/cmまでに造粒、成形すること
は、単位体積当たりの水素吸蔵量を増し、また、水素吸
蔵材料の実用化を推進する上で重要な特性である。
A fifth feature of the invention is that by setting the bulk density of the graphite agglomerate to 0.5 to 1.5 g / cm 3 , the hydrogen storage amount per volume is increased, and the carbon material for hydrogen storage is It is possible to reduce the volume. In this regard, the bulk density of the hydrogen storage material obtained by pulverization is generally 0.1 to 0.
Although it is 3 g / cm 3 , it is possible to improve the bulk density to about 1.2 g / cm 3 by using a wet type or dry type granulating device, and further it is possible to further increase the bulk density by compression using a press or a roll press. The bulk density can be increased. However, when the bulk density is increased to 1.6 g / cm 3 , the voids on the surface of the granulated product or the molded product are almost eliminated, and the hydrogen storage amount is significantly reduced. Therefore, granulating and molding the graphite aggregate to a bulk density of 1.5 g / cm 3 is important for increasing the hydrogen storage amount per unit volume and promoting the practical use of the hydrogen storage material. It is a characteristic.

【0011】発明の第6の特徴は、以上のような構造を
持つ黒鉛凝集体の中にPt、Pd、Ni、K、Liの何
れか1種以上を含有することである。この点は、試験か
ら、これらを含有することにより、水素吸蔵量が1.1
〜1.5倍程度まで増加できることが分かり、水素吸蔵
量を増大する上で効果的であることが確認された。ま
た、Ti、V、Cr、Mn、Fe、Co、Zr、Nbの
何れか1種以上を含有していても良い。なぜならば、カ
ーボンへの水素吸蔵は、水素分子状態より原子状水素の
方が小さいため、より良好な水素吸蔵性能が得られるか
らであり、水素分子を原子状水素へ分解する金属として
は、一般に水素吸蔵合金の主成分であるTi、V、Z
r、Nbの元素、及び原子番号57〜71のランタノイ
ドに属する金属元素、またはこれらの合金も有効であ
る。Ti、V、Zr、Nbよりは水素との親和力は弱ま
るが、上記金属存在下においては、Cr、Mn、Fe、
Coを混ぜた合金を添加することも有効である。Pt、
Pd、Ni、K、Li、Ti、V、Cr、Mn、Fe、
Co、Zr、Nbを黒鉛凝集体に含有させる方法として
は、含浸法、沈着法、イオン交換法、粉砕、混合真空焼
成などの手法が適用可能である。
A sixth feature of the invention is that the graphite agglomerate having the above structure contains at least one of Pt, Pd, Ni, K and Li. This point shows that the hydrogen storage capacity is 1.1 due to the inclusion of these.
It was found that the amount could be increased up to about 1.5 times, and it was confirmed to be effective in increasing the hydrogen storage amount. Moreover, any one or more of Ti, V, Cr, Mn, Fe, Co, Zr, and Nb may be contained. This is because hydrogen storage in carbon is smaller in atomic hydrogen than in hydrogen molecule state, and therefore better hydrogen storage performance can be obtained.As a metal that decomposes hydrogen molecules into atomic hydrogen, Ti, V, Z which are the main components of hydrogen storage alloy
Elements of r and Nb, metal elements belonging to the lanthanoids of atomic numbers 57 to 71, or alloys thereof are also effective. The affinity for hydrogen is weaker than Ti, V, Zr, and Nb, but in the presence of the above metals, Cr, Mn, Fe,
It is also effective to add an alloy containing Co. Pt,
Pd, Ni, K, Li, Ti, V, Cr, Mn, Fe,
As a method of incorporating Co, Zr, and Nb into the graphite aggregate, methods such as an impregnation method, a deposition method, an ion exchange method, pulverization, and mixed vacuum firing can be applied.

【0012】以上の黒鉛凝集体構造を調整するため、粉
砕機としてはボールミル、振動ミル、遊星ボールミル、
ジェットミルなどの単独、又は、組み合わせた粉砕態様
が工夫される。また、粉砕雰囲気は大気、アルゴン、窒
素、水素、真空粉砕などが好ましい。加えて粉砕後、賦
活処理、酸化剤での処理、熱処理などを適用して、黒鉛
凝集体の構造を上記した発明の特性値に合わせることも
有効な手法である。ここで、粉砕機の選定は粉砕後の黒
鉛構造を決定するために重要である。ボールミルではボ
ールによる衝撃、圧縮粉砕と摩砕で粉砕が進行する。ジ
ェットミルでは気流による衝撃粉砕と摩砕により粉砕が
進行する。振動ボールミルでは、粉砕媒体に挟まれた粒
子の衝撃粉砕と摩砕により粉砕が進行する。また、遊星
ボールミルでは、ポットの公転と自転により粉体媒体に
よる加速度を与え、圧縮・衝撃破砕と摩砕で粉砕が進行
する。特に黒鉛の粉砕では、圧縮・衝撃破砕の他に摩砕
効果の大きい遊星ボールミルの適用によって、より速く
粉砕を進めることができ、短時間で黒鉛の結晶子を小さ
くできる。しかし、比表面積が高く、細孔構造の発達し
た黒鉛を得るためには、粉砕媒体に挟まれた粒子の衝撃
粉砕と摩砕で粉砕がおこる振動ミルなどの方が、結晶性
を保ち、比表面積が高く、細孔容積の大きい粉砕物を調
製できる。したがって、水素吸蔵材料としての黒鉛構造
を最適化する粉砕方法は、原料の粒径、粉砕時間、粉砕
雰囲気などに応じ、最適な粉砕機を組み合わせることが
必要となる。次に、以上の発明を実施例を挙げて更に説
明する。
In order to adjust the above-mentioned graphite aggregate structure, as a crusher, a ball mill, a vibration mill, a planetary ball mill,
A pulverization mode such as a jet mill or a combination thereof may be devised. The crushing atmosphere is preferably air, argon, nitrogen, hydrogen, vacuum crushing, or the like. In addition, it is also an effective method to apply the activation treatment, the treatment with an oxidizing agent, the heat treatment, etc. after crushing to adjust the structure of the graphite aggregate to the characteristic value of the invention described above. Here, the selection of the crusher is important for determining the graphite structure after crushing. In a ball mill, crushing progresses by impact with balls, compression crushing and grinding. In a jet mill, crushing is carried out by impact crushing and attrition by an air stream. In a vibrating ball mill, crushing proceeds by impact crushing and grinding of particles sandwiched between grinding media. Further, in the planetary ball mill, acceleration due to the powder medium is given by the revolution and rotation of the pot, and the crushing proceeds by compression / shock crushing and grinding. In particular, in the case of crushing graphite, by applying a planetary ball mill having a great grinding effect in addition to compression / shock crushing, the crushing can be accelerated and the crystallites of graphite can be reduced in a short time. However, in order to obtain graphite with a high specific surface area and a well-developed pore structure, a vibration mill that crushes particles sandwiched in a crushing medium by impact crushing and attrition maintains crystallinity and A pulverized product having a high surface area and a large pore volume can be prepared. Therefore, in the pulverization method for optimizing the graphite structure as the hydrogen storage material, it is necessary to combine an optimal pulverizer according to the particle size of the raw material, the pulverization time, the pulverization atmosphere, and the like. Next, the above invention will be further described with reference to examples.

【0013】[0013]

【実施例】(実施例1〜4)この実施例は、発明対象と
なる黒鉛凝集体およびその有効性を調べた一例である。 〈試料の調製〉、平均粒径2〜100μmの天然黒鉛
(鱗片状黒鉛)、メソフェーズピッチ系黒鉛、人造黒鉛
を振動ボールミル、回転ボールミルを用いて、24〜9
6時間、真空中で粉砕し、結晶子の大きさ、凝集体の平
均粒径等の異なる表1中の各試料(実施例1〜4と比較
例1、2)を作製した。その際に行った細孔構造、X線
回折による構造解析、粒度分布、水素吸蔵量・放出量の
測定方法は以下のとおりである。
EXAMPLES (Examples 1 to 4) This example is an example in which the graphite aggregates to be invented and their effectiveness were investigated. <Preparation of sample>, natural graphite (scaly graphite) having an average particle diameter of 2 to 100 μm, mesophase pitch-based graphite, and artificial graphite were used for 24 to 9 using a vibrating ball mill and a rotating ball mill.
Each sample in Table 1 (Examples 1 to 4 and Comparative Examples 1 and 2) having different crystallite sizes, aggregate average particle diameters, and the like was prepared by pulverizing in vacuum for 6 hours. The pore structure, the structural analysis by X-ray diffraction, the particle size distribution, and the measurement method of the hydrogen storage amount / release amount performed at that time are as follows.

【0014】〈細孔構造の測定〉、各試料の比表面積
[m /g]の測定は、窒素吸着法を用い、解析にはB
runauer-Emmett-TellerによるBET式より求めた(準
拠規格:ISO 9277)。細孔分布の測定は、液体
窒素温度における毛管凝縮を利用するもので、Kelvinの
式が基礎となる。吸着平衡圧を広い範囲にわたり変えて
吸着等温線を描き、解析すると細孔分布が求まる。この
細孔分布の解析方法は、Barett、JoyerおよびHalendaに
よって提案された方法(BJH法)により解析した。細
孔径と細孔容積の関係を把握し、細孔半径0.85nm
から5nmまでの細孔容積を積算して求め、細孔半径5
nm以下の細孔容積とした。なお、比表面積、細孔系分
布(細孔径及び細孔容積)の測定装置はマイクロメトリ
ックス社製のASAP2010を使用した。〈X線回折
分析による測定〉、X線回折装置を用いて、学振法より
結晶子の大きさLc(002)、層間距離d(002)
を求めた。測定装置はマックサイエンス社製MXP18
VAHFを用いた。〈粒度分布の測定〉、レーザー回折
型粒度分布計を用いて、黒鉛凝集体の粒度分布を測定し
平均粒子径を求めた。測定では、各試料を界面活性剤を
用いて水中に均一に分布させ、超音波分散状態で粒度を
計測した。屈折率は1.70−0.20iを用いた。
<Measurement of pore structure> The specific surface area [m 2 / g] of each sample was measured by the nitrogen adsorption method, and B was used for the analysis.
It was obtained from the BET formula by runauer-Emmett-Teller (compliance standard: ISO 9277). The measurement of pore size distribution utilizes capillary condensation at liquid nitrogen temperature and is based on the Kelvin equation. When the adsorption equilibrium pressure is changed over a wide range and the adsorption isotherm is drawn and analyzed, the pore distribution can be obtained. The method of analyzing the pore distribution was analyzed by the method proposed by Barett, Joyer and Halenda (BJH method). Grasping the relationship between pore diameter and pore volume, pore radius 0.85 nm
To 5 nm and the pore radius is 5
The pore volume was nm or less. ASAP2010 manufactured by Micrometrics was used as a measuring device for the specific surface area and the pore system distribution (pore diameter and pore volume). <Measurement by X-ray diffraction analysis> Using an X-ray diffractometer, the crystallite size Lc (002) and the interlayer distance d (002) according to Gakushin method.
I asked. MXP18 manufactured by Mac Science Co., Ltd.
VAHF was used. <Measurement of particle size distribution> Using a laser diffraction type particle size distribution meter, the particle size distribution of the graphite aggregate was measured to obtain the average particle size. In the measurement, each sample was uniformly distributed in water using a surfactant, and the particle size was measured in an ultrasonically dispersed state. The refractive index used was 1.70-0.20i.

【0015】〈試料評価〉、実施例および比較例の各試
料はJIS7201、7203に準じた試験方法によ
り、水素吸蔵量と水素放出量の測定を行った。この測定
では、各試料を精秤した後、試料管に入れて真空排気し
た後、12Mpaまで水素圧を上げて水素吸蔵量[wt
%]を確認した。また、常温まで戻して水素放出量を確
認した。サイクル特性は吸蔵、放出を5回繰り返した後
の水素吸蔵量[wt%]を測定した。以上の試料構成お
よび評価結果を表1に示す。
<Evaluation of samples> The samples of Examples and Comparative Examples were subjected to measurement of hydrogen storage amount and hydrogen release amount by a test method according to JIS7201 and 7203. In this measurement, each sample was precisely weighed, put in a sample tube and evacuated, and then the hydrogen pressure was increased to 12 MPa to increase the hydrogen storage amount [wt.
%]It was confirmed. Also, the temperature was returned to room temperature and the amount of hydrogen released was confirmed. As the cycle characteristics, the hydrogen storage amount [wt%] after repeating storage and release 5 times was measured. Table 1 shows the above sample structure and evaluation results.

【0016】[0016]

【表1】 [Table 1]

【0017】実施例1〜4の各試料(黒鉛凝集体)は、
結晶子の大きさを1〜40nmの範囲に揃え、その凝集
体の平均粒径を1〜60μmに調製したときのものであ
り、同じ黒鉛凝集体の比較例1や2の試料と比較する
と、水素吸蔵量が何れも多く良好である。また、実施例
1〜4の各試料は、黒鉛凝集体の比表面積が300m
/g以上、平均細孔半径が5.5nm以下、層間距離が
0.3360〜0.3385nmの範囲であり、半径
5.0nm以下の細孔容積が0.3cm/g以上のも
のである。
The samples (graphite aggregates) of Examples 1 to 4 were
The size of the crystallites was adjusted to the range of 1 to 40 nm, and the average particle size of the aggregate was adjusted to 1 to 60 μm. When compared with the samples of Comparative Examples 1 and 2 of the same graphite aggregate, The hydrogen storage capacity is large and good. Further, in each of the samples of Examples 1 to 4, the specific surface area of the graphite aggregate was 300 m 2.
/ G or more, the average pore radius is 5.5 nm or less, the interlayer distance is in the range of 0.3360 to 0.3385 nm, and the pore volume with a radius of 5.0 nm or less is 0.3 cm 3 / g or more. .

【0018】(実施例5〜7)この実施例は、実施例2
の試料を用い、流動層造粒機およびプレス処理にて、嵩
密度を増加させた例である。その評価結果を表2に示
す。
(Examples 5 to 7) This example is the same as Example 2.
This is an example in which the bulk density was increased by using the sample of No. 2 by a fluidized bed granulator and press treatment. The evaluation results are shown in Table 2.

【0019】[0019]

【表2】 [Table 2]

【0020】実施例5〜7より、実施例2の試料(黒鉛
凝集体)を1.5g/cmの嵩密度まで造粒、成形し
ても、水素吸蔵能の大幅な減少はないが、嵩密度が1.
6g/cm以上になると、水素吸蔵能が大幅に減少す
ることが分かる。また、前記黒鉛凝集体は嵩密度0.5
g/cmから1.5g/cmの範囲にすることによ
り、体積当たりの水素貯蔵能(水素吸蔵量)を0.00
4g/cm 以上に保つことが可能になった。この結
果より、黒鉛凝集体の嵩密度を0.5〜1.5g/cm
まで造粒、成形することは、単位体積当たりの水素吸
蔵量を増し、また、水素吸蔵材料の実用化を推進する上
で、効果的であることが分かる。
From Examples 5 to 7, even if the sample (graphite agglomerate) of Example 2 was granulated and molded to a bulk density of 1.5 g / cm 3 , the hydrogen storage capacity was not significantly reduced. Bulk density is 1.
It can be seen that the hydrogen storage capacity is significantly reduced at 6 g / cm 3 or more. The graphite aggregate has a bulk density of 0.5.
By setting the range from g / cm 3 to 1.5 g / cm 3 , the hydrogen storage capacity per unit volume (hydrogen storage capacity) is 0.00
It has become possible to maintain at 4 g / cm 3 or more. From this result, the bulk density of the graphite aggregate was 0.5 to 1.5 g / cm.
It can be seen that granulating and molding up to 3 is effective in increasing the hydrogen storage amount per unit volume and promoting the practical application of the hydrogen storage material.

【0021】(実施例8〜12)この実施例は、Pt、
Pd、Ni、K、Liを黒鉛に含有したときの効果を調
べたときのもので、Pt担持、Pd担持、およびNi担
持黒鉛の調製は実施例2の試料(黒鉛凝集体)を用いた
例である。含有方法は、HPtCI、PdCI
又は、Ni(NOを純水に溶解させた後、試料
(実施例2の試料)を投入して十分に混合し、含浸さ
せ、乾燥させた。その後、400℃で水素還元し、黒鉛
凝集体表面にPt、PdまたはNiを分散させた。K、
Liの分散についてはステンレス容器内に実施例2の試
料(黒鉛凝集体)を入れ、真空脱気した後、Kについて
は280℃、Liについては420℃まで昇温させ、K
またはLiを黒鉛凝集体に分散させた。これら各試料の
水素吸蔵量特性の評価結果を表3に示す。何れの場合に
も、実施例2の試料構成より、水素吸蔵量およびサイク
ル特性共に向上できることが分かる。特に、Ptを含有
した実施例8のものでは1.5倍程度まで増大され、改
善効果が顕著に認められる。
(Examples 8 to 12) In this example, Pt,
The effect of containing Pd, Ni, K, and Li in graphite was investigated, and Pt-supported, Pd-supported, and Ni-supported graphite was prepared by using the sample (graphite aggregate) of Example 2. Is. The containing method is H 2 PtCI 6 , PdCI 2 ,
Alternatively, Ni (NO 3 ) 2 was dissolved in pure water, and then a sample (sample of Example 2) was charged, sufficiently mixed, impregnated, and dried. Then, hydrogen reduction was performed at 400 ° C. to disperse Pt, Pd or Ni on the surface of the graphite aggregate. K,
For the dispersion of Li, the sample (graphite agglomerate) of Example 2 was placed in a stainless steel container, deaerated in vacuum, and then heated to 280 ° C. for K and 420 ° C. for Li to obtain K.
Alternatively, Li was dispersed in the graphite aggregate. Table 3 shows the evaluation results of the hydrogen storage capacity characteristics of each of these samples. In any case, it can be seen that both the hydrogen storage amount and the cycle characteristics can be improved from the sample configuration of Example 2. In particular, in Example 8 containing Pt, the improvement effect was remarkably recognized because the Pt content was increased to about 1.5 times.

【0022】[0022]

【表3】 [Table 3]

【0023】[0023]

【発明の効果】以上のように、発明の黒鉛系水素吸蔵材
料及びその製造方法は、原料として入手および製造が容
易な結晶性の高い黒鉛を用い、粉砕機選定と粉砕条件の
最適化により、ナノ構造化した黒鉛が凝集した黒鉛凝集
体を調製し、水素吸蔵量の高い材料物性を実現できる。
これにより、この発明は、大量の水素を効率的に吸蔵で
き、軽量で、繰り返し使用できる上、製造方法も容易で
あり製造費を抑えて実用化に寄与できる。
INDUSTRIAL APPLICABILITY As described above, the graphite-based hydrogen storage material of the present invention and the method for producing the same use graphite having high crystallinity, which is easy to obtain and manufacture, as a raw material, By preparing a graphite aggregate in which nanostructured graphite is aggregated, it is possible to realize material properties with a high hydrogen storage capacity.
As a result, the present invention can efficiently store a large amount of hydrogen, is light in weight, can be repeatedly used, and has a simple manufacturing method, which can reduce the manufacturing cost and contribute to practical use.

フロントページの続き (72)発明者 飯田 淳一 千葉県香取郡多古町水戸1番地 日立粉末 冶金株式会社内 (72)発明者 伊藤 仁 神奈川県横浜市神奈川区宝町2番地 日産 自動車株式会社内 (72)発明者 片村 淳二 神奈川県横浜市神奈川区宝町2番地 日産 自動車株式会社内 (72)発明者 川合 幹夫 神奈川県横浜市神奈川区宝町2番地 日産 自動車株式会社内 Fターム(参考) 4G066 AA04B BA09 BA20 BA25 BA26 BA31 CA38 4G140 AA32 AA36 AA48 4G146 AA02 AA16 AB04 AB10 AC03A AC03B AC05A AC05B AC07A AC07B AC08A AC08B AC14A AC14B AC22A AC22B AD32 BA02 BA23 BA43 CB09 Continued front page    (72) Inventor Junichi Iida             Hitachi Powder, 1 Mito, Tako-cho, Katori-gun, Chiba Prefecture             Within Metallurgical Co., Ltd. (72) Inventor Hitoshi Ito             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Junji Katamura             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Mikio Kawai             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation F-term (reference) 4G066 AA04B BA09 BA20 BA25                       BA26 BA31 CA38                 4G140 AA32 AA36 AA48                 4G146 AA02 AA16 AB04 AB10 AC03A                       AC03B AC05A AC05B AC07A                       AC07B AC08A AC08B AC14A                       AC14B AC22A AC22B AD32                       BA02 BA23 BA43 CB09

Claims (7)

【特許請求の範囲】[Claims] 【請求項1】 結晶子の大きさが1〜40nmのナノ構
造化した黒鉛が凝集した黒鉛凝集体からなり、該黒鉛凝
集体の平均粒径が1〜60μmであることを特徴とする
黒鉛系水素吸蔵材料。
1. A graphite system comprising a graphite aggregate in which nanostructured graphite having a crystallite size of 1 to 40 nm is aggregated, and the graphite aggregate has an average particle size of 1 to 60 μm. Hydrogen storage material.
【請求項2】 前記黒鉛凝集体の比表面積が300m
/g以上、平均細孔半径が5.5nm以下、層間距離が
0.3360〜0.3385nmである請求項1に記載
の黒鉛系水素吸蔵材料。
2. The specific surface area of the graphite aggregate is 300 m 2.
/ G or more, the average pore radius is 5.5 nm or less, the interlayer distance is 0.3360 to 0.3385 nm, the graphite-based hydrogen storage material according to claim 1.
【請求項3】 前記黒鉛凝集体の細孔半径5.0nm以
下の細孔容積が0.3cm/g以上である請求項1又
は2に記載の黒鉛系水素吸蔵材料。
3. The graphite-based hydrogen storage material according to claim 1, wherein a volume of pores having a pore radius of 5.0 nm or less of the graphite aggregate is 0.3 cm 3 / g or more.
【請求項4】 前記黒鉛凝集体の嵩密度が0.5〜1.
5g/cmである請求項1から3の何れかに記載の黒
鉛系水素吸蔵材料。
4. The bulk density of the graphite aggregate is 0.5 to 1.
The graphite-based hydrogen storage material according to any one of claims 1 to 3, which has a weight of 5 g / cm 3 .
【請求項5】 前記黒鉛凝集体の中にPt、Pd、N
i、K、Li、Ti、V、Cr、Mn、Fe、Co、Z
r、Nbの何れか1種以上を含有している請求項1から
4の何れかに記載の黒鉛系水素吸蔵材料。
5. Pt, Pd, N in the graphite aggregate
i, K, Li, Ti, V, Cr, Mn, Fe, Co, Z
The graphite-based hydrogen storage material according to claim 1, which contains at least one of r and Nb.
【請求項6】 結晶子の大きさが20nm以上の原料黒
鉛を用い、粉砕処理により請求項1から4に記載の黒鉛
凝集体として作製する黒鉛系水素吸蔵材料の製造方法。
6. A method for producing a graphite-based hydrogen storage material, wherein raw graphite having a crystallite size of 20 nm or more is used, and the graphite aggregate is produced by pulverization treatment.
【請求項7】 Pt、Pd、Ni、K,Li、Ti、
V、Cr、Mn、Fe、Co、Zr、Nbの何れか一種
以上の元素を前記黒鉛凝集体に含有処理する請求項6に
記載の黒鉛系水素吸蔵材料の製造方法。
7. Pt, Pd, Ni, K, Li, Ti,
The method for producing a graphite-based hydrogen storage material according to claim 6, wherein the graphite agglomerate contains at least one element selected from V, Cr, Mn, Fe, Co, Zr, and Nb.
JP2002126296A 2002-04-26 2002-04-26 Graphite-based hydrogen-occluding material and method for producing the same Pending JP2003321215A (en)

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JP2006008472A (en) * 2004-06-29 2006-01-12 Hitachi Powdered Metals Co Ltd Nano-structured graphite, its composite material, conductive material and catalyst material using them
JP2007001810A (en) * 2005-06-23 2007-01-11 Kinousei Mokushitsu Shinsozai Gijutsu Kenkyu Kumiai Manufacturing method of carbon material
JP2008063219A (en) * 2006-09-07 2008-03-21 Samsung Sdi Co Ltd Porous carbon and method for producing the same
US20190058197A1 (en) * 2014-09-09 2019-02-21 Tohoku Techno Arch Co., Ltd. Method for producing porous graphite, and porous graphite

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006008472A (en) * 2004-06-29 2006-01-12 Hitachi Powdered Metals Co Ltd Nano-structured graphite, its composite material, conductive material and catalyst material using them
JP2007001810A (en) * 2005-06-23 2007-01-11 Kinousei Mokushitsu Shinsozai Gijutsu Kenkyu Kumiai Manufacturing method of carbon material
JP2008063219A (en) * 2006-09-07 2008-03-21 Samsung Sdi Co Ltd Porous carbon and method for producing the same
US20190058197A1 (en) * 2014-09-09 2019-02-21 Tohoku Techno Arch Co., Ltd. Method for producing porous graphite, and porous graphite
US10763511B2 (en) * 2014-09-09 2020-09-01 Tohoku Techno Arch Co., Ltd. Method for producing porous graphite, and porous graphite

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