JP4143108B2 - Graphite particles - Google Patents
Graphite particles Download PDFInfo
- Publication number
- JP4143108B2 JP4143108B2 JP2007197361A JP2007197361A JP4143108B2 JP 4143108 B2 JP4143108 B2 JP 4143108B2 JP 2007197361 A JP2007197361 A JP 2007197361A JP 2007197361 A JP2007197361 A JP 2007197361A JP 4143108 B2 JP4143108 B2 JP 4143108B2
- Authority
- JP
- Japan
- Prior art keywords
- graphite
- graphite particles
- particles
- particle
- laminated structure
- 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.)
- Expired - Fee Related
Links
Images
Classifications
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Description
本発明は、リチウム二次電池用の負極材料や燃料電池用のセパレータ材料等に好適な略球状の黒鉛粒子、及びその製造方法に関する。 The present invention relates to a substantially spherical graphite particle suitable for a negative electrode material for a lithium secondary battery, a separator material for a fuel cell, and the like, and a method for producing the same.
黒鉛粒子は、リチウム二次電池用の負極材料として、また、燃料電池用セパレータの材料等として用途が拡大している。これらに用いる黒鉛は、天然黒鉛と人造黒鉛とに大別できる。 The use of graphite particles is expanding as a negative electrode material for lithium secondary batteries and as a material for fuel cell separators. The graphite used for these can be roughly classified into natural graphite and artificial graphite.
天然黒鉛を粉砕して得られる黒鉛粒子は、粒子形状が鱗片状（板状）であり、その結晶構造に基因して粒子全体に顕著な異方性を認めることができる。即ち、黒鉛結晶は、大きく広がったＡＢ面がＣ軸方向に多数積層した構造になっているが、ＡＢ面の広がりに対して積層の厚みが薄いために全体として板状をなしている。 Graphite particles obtained by pulverizing natural graphite have a scaly shape (plate shape), and remarkable anisotropy can be recognized throughout the particles due to their crystal structure. That is, the graphite crystal has a structure in which a large number of AB planes that are greatly spread are laminated in the C-axis direction, but has a plate shape as a whole because the thickness of the lamination is thin with respect to the spread of the AB plane.
リチウム二次電池の負極は、銅箔等の集電体の表面に薄い黒鉛層を形成したものが一般的である。電池の充放電容量を大きくするためには黒鉛層の密度は高い方が好ましい。このため、通常プレスや圧延等により黒鉛層を圧縮してその密度を高めて使用している。 A negative electrode of a lithium secondary battery generally has a thin graphite layer formed on the surface of a current collector such as a copper foil. In order to increase the charge / discharge capacity of the battery, the graphite layer preferably has a higher density. For this reason, the graphite layer is usually compressed by pressing or rolling to increase its density.
しかし、天然黒鉛を用いる場合には、黒鉛粒子が薄い鱗片状（板状）であるため、プレスや圧延等を用いて黒鉛を圧縮すると、圧縮力を受ける黒鉛粒子の板面（ＡＢ面）が圧縮面と平行になるように黒鉛粒子が配向する。 However, when natural graphite is used, the graphite particles are thin scaly (plate-like), so when the graphite is compressed using a press, rolling or the like, the plate surface (AB surface) of the graphite particles that receives the compressive force is reduced. The graphite particles are oriented so as to be parallel to the compression surface.
即ち、黒鉛層を形成する個々の板状の黒鉛粒子は、そのＡＢ面が集電体の表面と平行となるように配向する。成型体中における黒鉛粒子のこのような配向を、以下単に「配向」と称する。 That is, the individual plate-like graphite particles forming the graphite layer are oriented so that their AB faces are parallel to the surface of the current collector. Such orientation of the graphite particles in the molded body is hereinafter simply referred to as “orientation”.
電池の負極において配向を生ずることは、好ましくない。その理由は、まず、電解液は黒鉛のＡＢ面を通過できないので、配向している黒鉛層の内部に電解液が非常に浸透し難くなる。その結果、黒鉛と電解液との接触が黒鉛層の表面付近に偏ることになる。次ぎに、黒鉛結晶の導電性は、ＡＢ面の方向に大きく、Ｃ軸方向に小さい。一方、黒鉛層における電気の流れは厚み方向であり、この方向は配向した黒鉛粒子のＣ軸方向になる。このため、電極の電気抵抗が大きくなる。その結果、電池の充放電容量が小さくなる。 It is not preferable to cause orientation in the negative electrode of the battery. The reason is that, since the electrolytic solution cannot pass through the AB surface of graphite, the electrolytic solution hardly penetrates into the oriented graphite layer. As a result, the contact between the graphite and the electrolyte is biased near the surface of the graphite layer. Next, the conductivity of the graphite crystal is large in the AB plane direction and small in the C-axis direction. On the other hand, the flow of electricity in the graphite layer is the thickness direction, and this direction is the C-axis direction of the oriented graphite particles. For this reason, the electrical resistance of an electrode becomes large. As a result, the charge / discharge capacity of the battery is reduced.
燃料電池のセパレーターは、粒子状黒鉛と樹脂とを混合して、プレスすることにより板状に成型している。このセパレーターの主な役割は、燃料ガスと酸素含有ガスとが混合しないようにガスの流れを仕切ることにあるが、同時に集電体としての役割もあり、この場合電気の流れは厚みの方向である。従って、リチウム二次電池用の負極材料と同様に、セパレーターに配向を生ずることは好ましくない。 The separator of the fuel cell is formed into a plate shape by mixing particulate graphite and resin and pressing. The main role of this separator is to partition the gas flow so that the fuel gas and oxygen-containing gas do not mix, but at the same time, it also serves as a current collector. In this case, the flow of electricity is in the direction of thickness. is there. Accordingly, it is not preferable that the separator is oriented as in the negative electrode material for the lithium secondary battery.
その他、多くの黒鉛電極についても、同様に配向の問題を伴うことが多い。 In addition, many graphite electrodes are often accompanied by orientation problems.
人造黒鉛はその製造方法によって球状に近い形状にすることが可能であり、同時に、異方性の少ない粒子とすることも可能である。例えば、黒鉛のＡＢ面を同心円に沿って配向させて積層した球状の粒子や、黒鉛のＡＢ面が同心円状に積層した円筒状の粒子を作ることができる。 Artificial graphite can be made into a nearly spherical shape by its production method, and at the same time, it can be made into particles with little anisotropy. For example, spherical particles in which the AB surface of graphite is oriented and stacked along a concentric circle, or cylindrical particles in which the AB surface of graphite is concentrically stacked can be produced.
しかし、このような人造黒鉛は、一般に高価である上、結晶化度は低くなる。負極材料として用いる場合、結晶化度の低い黒鉛は、黒鉛の単位質量当りの充放電容量が小さくなるので好ましくない。 However, such artificial graphite is generally expensive and has a low crystallinity. When used as a negative electrode material, graphite having a low crystallinity is not preferable because the charge / discharge capacity per unit mass of graphite becomes small.
また、セパレーターの材料として用いる場合、結晶化度の低い黒鉛は導電性が低いので好ましくない。 Further, when used as a separator material, graphite having a low crystallinity is not preferable because of its low conductivity.
一方、結晶化度を高くした人造黒鉛は、その性状が天然黒鉛の性状に近いものになる。従って、結晶化度の高い人造黒鉛は、これを粉砕した場合には、天然黒鉛と同様に鱗片状の粒子形状を示す。 On the other hand, artificial graphite having a high degree of crystallinity has properties close to those of natural graphite. Therefore, artificial graphite having a high degree of crystallinity, when pulverized, exhibits a scaly particle shape like natural graphite.
本発明者らは、異方性の少ない黒鉛粒子を得るために、数多くの粉砕機を用いて高結晶性黒鉛の粉砕方法を検討した。 In order to obtain graphite particles with little anisotropy, the present inventors have studied a method for pulverizing highly crystalline graphite using a number of pulverizers.
平均粒径１００μｍ以上の黒鉛粒子を得るための粗粉砕機としては、ジョウクラッシャー、ジャイレトリークラッシャー、ロールクラッシャー等がある。 Examples of the coarse pulverizer for obtaining graphite particles having an average particle size of 100 μm or more include a jaw crusher, a gyre crusher, and a roll crusher.
平均粒径１００μｍ以下の黒鉛粒子を得るための微粉砕機としては、ローラーミル、回転ディスクミル、パンミル、リングロールミル、インパクトクラッシャー、振動ロッドミル、振動ディスクミル、振動ボールミル、ボールミル、ジェットミル等がある。 Examples of the fine pulverizer for obtaining graphite particles having an average particle size of 100 μm or less include a roller mill, a rotating disk mill, a pan mill, a ring roll mill, an impact crusher, a vibrating rod mill, a vibrating disk mill, a vibrating ball mill, a ball mill, and a jet mill. .
これらの粉砕機は、何れも黒鉛に対して強力な剪断力、圧縮力、衝撃力を与えるので、黒鉛を短時間で粉砕できる。しかし、多くの場合、粉砕して得た黒鉛粒子の粒子形状は鱗片状である。 All of these pulverizers give a strong shearing force, compressive force, and impact force to the graphite, so that the graphite can be pulverized in a short time. However, in many cases, the particle shape of the graphite particles obtained by pulverization is scaly.
元来、高結晶性の黒鉛は、炭素原子が網目構造を形成して平面状に広がるＡＢ面が、多数積層することにより厚みを増し、塊状に成長したものである。積層したＡＢ面相互間の結合力（Ｃ軸方向の結合力）は、ＡＢ面の面内方向の結合力に比べて遥かに小さいので、特別の工夫がない限り、結合力の弱いＡＢ面間の剥離が優先して起り、得られる黒鉛粒子の形状は鱗片状になる。 Originally, highly crystalline graphite has a structure in which a large number of AB planes, in which carbon atoms form a network structure and spread in a planar shape, are stacked to increase the thickness and grow into a lump. The bonding force between the laminated AB surfaces (C-axis direction bonding force) is much smaller than the bonding force in the in-plane direction of the AB surface, so unless there is a special measure between the AB surfaces with weak bonding force Peeling occurs preferentially, and the resulting graphite particles have a scaly shape.
黒鉛粒子の内部組織は、電子顕微鏡で観察できる。特に、黒鉛のＡＢ面に垂直な断面を観察すると、積層構造を示す筋状の線を観察することができる。 The internal structure of the graphite particles can be observed with an electron microscope. In particular, when a cross section perpendicular to the AB surface of graphite is observed, a streak line indicating a laminated structure can be observed.
電子顕微鏡観察によれば、鱗片状の黒鉛粒子の内部組織は単純である。ＡＢ面に垂直な断面を観察すると、積層構造を示す筋状の線は常に直線状であって、平板状の黒鉛層が積層したものであることが解る。 According to an electron microscope observation, the internal structure of the scaly graphite particles is simple. When a cross section perpendicular to the AB plane is observed, it is understood that the streak line indicating the laminated structure is always linear, and is a laminate of flat graphite layers.
以後、このようにして観察される積層した内部組織を「積層構造」という。 Hereinafter, the laminated internal structure thus observed is referred to as “laminated structure”.
本発明者らは、黒鉛の微粉砕において、振動ロッドミル、振動ディスクミル、又は振動ボールミルを用いる場合は、例外的に紡錘状の黒鉛粒子が得られることを見出した。これは、粉砕と共に圧縮成型が行われるためであり、特に、振動ロッドミルを使用した場合に顕著である。 The inventors of the present invention have found that spindle-shaped graphite particles are exceptionally obtained when a vibrating rod mill, a vibrating disk mill, or a vibrating ball mill is used for finely pulverizing graphite. This is because compression molding is performed together with pulverization, and is particularly remarkable when a vibrating rod mill is used.
しかし、前記紡錘状となった黒鉛粒子においても、その内部組織を電子顕微鏡観察すると直線状の積層構造であり、かつ、ＡＢ面は粒子の長軸にほぼ平行である。即ち、外観上は鱗片状から紡錘状に変化させることが出来るが、内部組織については変化が見られない。従って、紡錘状の黒鉛粒子は、鱗片状の黒鉛粒子よりも配向を起こし難いものの、前述の課題を解決するには不十分である。 However, the spindle-shaped graphite particles also have a linear laminated structure when the internal structure is observed with an electron microscope, and the AB surface is substantially parallel to the long axis of the particles. That is, the appearance can be changed from a scaly shape to a spindle shape, but no change is seen in the internal tissue. Therefore, spindle-shaped graphite particles are less likely to cause orientation than scaly graphite particles, but are insufficient to solve the above-described problems.
本発明者らは、更に種々の粉砕機を用いて、粉砕方法を変えて高結晶性黒鉛の粉砕を行い、その際得られる黒鉛粒子の内部組織の変化について検討した。その結果、比較的粉砕力の小さい衝撃式粉砕機を用いる場合は、黒鉛の内部組織が変化することを発見した。即ち、直線状の積層構造が曲線状の積層構造に変化することを発見した。 The present inventors further examined the change in the internal structure of the graphite particles obtained by pulverizing highly crystalline graphite using various pulverizers by changing the pulverization method. As a result, it was discovered that the internal structure of graphite changes when an impact pulverizer with relatively small pulverization force is used. That is, it has been found that a linear laminated structure changes to a curved laminated structure.
また、原料黒鉛を気流と共に粉砕機に供給する場合、この曲線状の積層構造に変化する作用が顕著になることを発見した。更に、この粉砕方法を繰り返し行うことにより、黒鉛粒子が球状化することを発見した。 Moreover, when supplying raw material graphite to a grinder with an airflow, it discovered that the effect | action which changes to this curvilinear laminated structure became remarkable. Furthermore, it has been found that the graphite particles are spheroidized by repeating this pulverization method.
更に、球状化した黒鉛粒子の各種特性についてデータを集積した結果、この黒鉛粒子が当初の目的を達成し得るものであることを確認し、本発明を完成するに至った。 Furthermore, as a result of accumulating data on various characteristics of the spheroidized graphite particles, it was confirmed that the graphite particles can achieve the original purpose, and the present invention has been completed.
従って、本発明は高結晶性の黒鉛を加工することにより、球状に近い粒子形状の黒鉛粒子を得ること、及び本質的に異方性の少ない黒鉛粒子を得ることを目的とする。 Accordingly, an object of the present invention is to obtain graphite particles having a nearly spherical particle shape by processing highly crystalline graphite, and to obtain graphite particles having essentially low anisotropy.
上記目的を達成する本発明は、以下に示すものである。 The present invention for achieving the above object is as follows.
〔１〕 一個の鱗片状黒鉛粒子が２つに折り畳まれて球状化してなり、平均粒子径が５〜１００μｍであり、その内部に積層構造を有し、前記積層構造は前記球状黒鉛粒子表面から中心方向に向けて粒子表面の丸みに沿った曲線状の積層構造であり、前記積層構造をなす黒鉛結晶のＡＢ面は前記球状黒鉛粒子表面と一致しており、前記球状黒鉛粒子表面が黒鉛結晶のＡＢ面で構成されている長軸/短軸比が２以下の球状黒鉛粒子。 [1] One scaly graphite particle is folded into two to be spheroidized, has an average particle diameter of 5 to 100 μm, has a laminated structure therein, and the laminated structure extends from the surface of the spherical graphite particle. a curved laminated structure along the roundness of the particle surface toward the center, AB plane of graphite crystal forming the laminated structure is consistent with the spherical graphite particle surface, the spherical graphite particle surface is graphite crystal Spherical graphite particles having a major axis / minor axis ratio of 2 or less, which is constituted by the AB plane .
〔２〕Ｘ線回折装置により測定した黒鉛粒子の格子定数Ｃｏ(００２)が０．６７０〜０．６７２ｎｍである〔１〕に記載の球状黒鉛粒子。 [ 2 ] The spherical graphite particles according to [ 1 ], wherein the lattice constant Co (002) of the graphite particles measured by an X-ray diffractometer is 0.670 to 0.672 nm.
〔３〕タップ密度が０．６〜１．４ｇ／ｃｍ3である〔１〕又は〔２〕に記載の球状黒鉛粒子。 [ 3 ] The spherical graphite particles according to [1] or [2] , wherein the tap density is 0.6 to 1.4 g / cm 3 .
〔４〕黒鉛粒子混合物であって、〔１〕乃至〔３〕の何れかに記載の球状黒鉛粒子を１０質量％以上含むことを特徴とする黒鉛粒子混合物。 [4] A black lead particle mixture, [1] to graphite particles mixture of spherical graphite particles, characterized in that it comprises more than 10 wt% of any one of [3].
本発明の黒鉛粒子は、その内部に褶曲した積層構造を有し、外形が球状に近いため黒鉛粒子自体が物性的に等方性を有する。このため、この黒鉛粒子を用いて製造する各種成形体は配向の発現が少なく、例えば電極材料として使用する場合は電気抵抗の小さいものを製造することができる。さらに、本発明の黒鉛粒子は黒鉛の高結晶性を維持しているので、高結晶性黒鉛の有する優れた機能を保持した黒鉛成型体を得ることができる。 The graphite particles of the present invention have a laminated structure that is bent inside thereof, and since the outer shape is nearly spherical, the graphite particles themselves are physically isotropic. For this reason, the various molded products manufactured using the graphite particles have little expression of orientation, and for example, when used as an electrode material, a product having a low electrical resistance can be manufactured. Furthermore, since the graphite particles of the present invention maintain the high crystallinity of graphite, it is possible to obtain a graphite molded body that retains the excellent functions of high crystalline graphite.
また本発明黒鉛粒子は、汎用のピンミルを用いることにより、簡単に褶曲した積層構造を有する黒鉛粒子を製造できる。 In addition, the graphite particles of the present invention can be easily produced by using a general-purpose pin mill .
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
黒鉛粒子の内部組織の変化を説明するために、一個の鱗片状（平板状）の黒鉛粒子にＡＢ面方向の圧縮力が一定の方向で作用したと仮定すると、次のようになる。 In order to explain the change in the internal structure of the graphite particles, assuming that the compressive force in the AB plane direction acts on one scale-like (flat plate) graphite particle in a fixed direction, the following is obtained.
先ず、面方向の圧縮力を受けることにより、鱗片状（平板状）の黒鉛粒子は、曲板状に変形する。 First, by receiving a compressive force in the surface direction, the scale-like (flat plate) graphite particles are deformed into a curved plate shape.
繰り返し圧縮力を受けると変形が著しくなり、圧縮力は平板を折り曲げるように作用し、折り曲げられた内側の面が次第に向合うようになる。 When the compression force is repeatedly applied, the deformation becomes remarkable, the compression force acts to bend the flat plate, and the bent inner surfaces gradually face each other.
更に繰り返し圧縮力を受けると、圧縮力は向合う面が密着するように作用し、最終的には鱗片状（平板状）の黒鉛粒子が二つ折に折り畳まれた状態になる。 When the compressive force is further repeatedly applied, the compressive force acts so that the facing surfaces are in close contact with each other, and finally the scaly (flat) graphite particles are folded in two.
実際の粉砕における黒鉛粒子の変形はこのように単純ではなく、複雑な現象を伴うものと考えられる。例えば、鱗片状の黒鉛粒子がＡＢ面に平行な圧縮力を繰返し受けるならば、その方向は上記のように一定ではなく、板状の先端部には必ずこれを丸め込む力が作用するものと考えられる。 It is considered that the deformation of the graphite particles in actual pulverization is not as simple as this and involves complicated phenomena. For example, if scaly graphite particles repeatedly receive a compressive force parallel to the AB surface, the direction is not constant as described above, and it is considered that a force that rounds the plate-like tip always acts on the plate-like tip. It is done.
また、鱗片状に粉砕されるまでの過程や粒子相互間においても、複雑な変化があるものと考えられる。そして、様々な形態で繰り返し圧縮力を受けることによって、黒鉛粒子が次第に球状化するものと考えられる。 In addition, it is considered that there is a complicated change in the process until particles are crushed and between particles. And it is thought that a graphite particle gradually spheroidizes by receiving compressive force repeatedly in various forms.
実際に圧縮処理した黒鉛粒子を観察すると、その外観は球状に近いものである。また、その内部組織を電子顕微鏡で観察すると、積層構造を示す筋状の線は曲線状のものが多く、著しく複雑な積層構造になっていることが認められる。更に、粒子の内部には空隙も多く認められる。 When the actually compressed graphite particles are observed, the appearance is almost spherical. Further, when the internal structure is observed with an electron microscope, it is recognized that the streak lines indicating the laminated structure are often curved and have a remarkably complicated laminated structure. Furthermore, many voids are recognized inside the particles.
更に特徴的なことは、不作為に選んだ断面であっても、粒子の表面近傍には必ず積層構造の存在を観察できると共に、粒子表面から中心方向に向けて粒子表面の丸みに沿った曲線状の積層構造が観察できることである。 What is more characteristic is that even if it is a randomly selected cross section, the existence of a layered structure can always be observed in the vicinity of the particle surface, and a curved shape along the roundness of the particle surface from the particle surface toward the center. The laminated structure can be observed.
即ち、黒鉛粒子は球状に近い粒子形状であり、しかも、概ね粒子表面が黒鉛結晶のＡＢ面になっている。 That is, the graphite particles have a substantially spherical particle shape, and the particle surface is generally the AB surface of the graphite crystal.
このように、元々直線状であった積層構造が、圧縮力によって曲線状に変化することを「褶曲」ということにする。 In this way, the fact that the layered structure, which was originally linear, changes into a curved shape due to the compressive force is referred to as “folding”.
本発明の黒鉛粒子は、その内部に圧縮力により褶曲した積層構造を有することを特徴とし、粒子表面付近には多くの褶曲した積層構造を有するものである。 The graphite particles of the present invention are characterized by having a laminated structure that is bent by a compressive force therein, and has many bent laminated structures near the particle surface.
本発明の黒鉛粒子を得るために使用する衝撃式粉砕機としては、ピンミルを使用することが好ましい。 The impact grinder used for obtaining the graphite particles of the present invention, is preferred that you use the pin Nmiru.
ピンミルは、円筒状のケーシングの内部を複数個のピンが回転する粉砕機であり、黒鉛粒子を回転するピン及び固定ピンに衝突させて粉砕する。 The pin mill is a crusher in which a plurality of pins rotate inside a cylindrical casing, and crushes graphite particles by colliding with rotating pins and fixed pins.
比較的小さな衝撃力を与えるために、ピンの回転速度は、通常の粉砕の場合よりも遅い方が好ましく、回転ピンの線速度は５０〜２００ｍ／秒程度にすることが好ましい。 To give a relatively small impact force, the rotational speed of the pin, the slower is preferable than conventional milling, the linear velocity of the rotation pin is preferably about 50 to 200 m / sec.
また、粉砕機に黒鉛粒子を供給したり、排出する方法としては、黒鉛粒子を空気等の気流に同伴させて行うことが好ましい。 Further, as a method for supplying or discharging graphite particles to a pulverizer, it is preferable to carry out by allowing the graphite particles to accompany an air flow such as air.
気流に同伴させるためには、粉砕機は、原料供給口が軸芯部分に設けられると共に、粉砕物の排出口がケーシングの外周部分に設けられている構造のものが好ましい。 In order to accompany the airflow, the pulverizer preferably has a structure in which the raw material supply port is provided in the shaft core portion and the pulverized product discharge port is provided in the outer peripheral portion of the casing.
黒鉛粒子を気流に同伴させて粉砕処理することが有効である理由は明確ではない。しかし、少なくとも板状の黒鉛粒子は、気流中においてその板面方向が気体の流れ方向と平行になるものと考えられる。そして、この板状の黒鉛粒子がピンの打撃面等に衝突するときには、板面の先端部分に衝撃力が加わるものと考えられる。 The reason why it is effective to pulverize the graphite particles with the air current is not clear. However, it is considered that at least the plate-like graphite particles have a plate surface direction parallel to the gas flow direction in the airflow. And when this plate-like graphite particle collides with the impact surface etc. of a pin , it is thought that an impact force is added to the front-end | tip part of a plate surface.
従って、板状の黒鉛粒子には、そのＡＢ面に平行な圧縮力が作用し、その結果前述のような変形を起こし、球状化するものと考えられる。 Therefore, it is considered that a compression force parallel to the AB surface acts on the plate-like graphite particles, and as a result, the deformation as described above is caused and spheroidized.
本発明の黒鉛粒子を得るためには、このように比較的小さな衝撃力を繰り返して与えることが重要である。 In order to obtain the graphite particles of the present invention, it is important to repeatedly apply such a relatively small impact force.
黒鉛粒子を気流に同伴させて回分式で粉砕処理する場合には、少なくとも１０回以上の繰返し粉砕処理が必要であり、これは多少煩雑な場合がある。 In the case where the graphite particles are pulverized batchwise while being entrained in an air stream, at least 10 repeated pulverization processes are required, which may be somewhat complicated.
しかし、これを連続的に処理とすることは容易である。そのフローの一例を図１に示す。定量供給機１によって計量された原料黒鉛１１は、空気１２に搬送されて、空気と共に衝撃式粉砕機２へ送られる。衝撃式粉砕機２で粉砕処理された粉砕黒鉛と空気１３はバグフィルター３に送られ、空気と粉砕黒鉛に分離される。空気１４は外部に放出される。バグフィルター３で分離された粉砕黒鉛１５は、篩４に送られ、ここで選別され、粉砕黒鉛篩上粒子と粉砕黒鉛篩下粒子とに分けられる。
However, it is easy to process this continuously. An example of the flow is shown in FIG. The raw material graphite 11 weighed by the
粉砕黒鉛篩上粒子１６は、原料黒鉛１１と共に再び衝撃式粉砕機２へ送られ、以後同様に上記操作が繰返される。 The crushed graphite sieve particles 16 are sent again to the impact pulverizer 2 together with the raw material graphite 11, and the above operation is repeated thereafter.
粉砕黒鉛篩下粒子１７は、分級機５へ送られ、過粉砕された黒鉛微粒子１９が除去される。これにより、本発明の球状黒鉛粒子１８が得られる。
The pulverized
なお、衝撃式粉砕機２に供給する空気の供給方法としては、供給部にファンを設けて空気１２を加圧供給してもよいし、排気部にファンを設けて空気１４を吸引してもよい。
As a method for supplying air supplied to the impact type pulverizer 2, a fan may be provided in the supply unit and the air 12 may be supplied under pressure, or a fan may be provided in the exhaust unit and the
前述のように、衝撃式粉砕機を組込んだ上記連続処理装置を用いて黒鉛粒子を処理することにより、ほぼ球状化（球状に近い粒子形状）した本発明黒鉛粒子を得ることができる。 As described above, the graphite particles of the present invention that are substantially spheroidized (particle shape close to a sphere) can be obtained by processing the graphite particles using the above-described continuous processing apparatus incorporating an impact pulverizer.
また、上記の装置において、原料黒鉛１１に返送する粉砕黒鉛篩上粒子１６の返送割合を適宜変えることにより、得られる黒鉛粒子中の球状化した黒鉛粒子の占める割合を調節することも可能である。 In the above apparatus, it is also possible to adjust the ratio of spheroidized graphite particles in the obtained graphite particles by appropriately changing the return ratio of the pulverized graphite sieve particles 16 returned to the raw graphite 11. .
本発明の黒鉛粒子を得るために用いる原料黒鉛としては、天然黒鉛でもよいし、人造黒鉛でもよい。 The raw material graphite used for obtaining the graphite particles of the present invention may be natural graphite or artificial graphite.
本発明黒鉛粒子は、高結晶性黒鉛が持つ機能を活かすことを目的とするものであるから、原料黒鉛としては人造黒鉛の場合も黒鉛化の高いものが好ましい。例えば、２６００℃以上の温度で黒鉛化処理がなされた黒鉛、又は硼素等を添加することにより黒鉛化を促進して得られた黒鉛が好ましい。 Since the graphite particles of the present invention are intended to take advantage of the function of highly crystalline graphite, the raw graphite is preferably highly graphitized even in the case of artificial graphite. For example, graphite that has been graphitized at a temperature of 2600 ° C. or higher, or graphite obtained by promoting graphitization by adding boron or the like is preferable.
黒鉛の結晶性を示す黒鉛格子定数Ｃｏ（００２）の値としては、０．６７０〜０．６７２ｎｍが好ましい。 The value of the graphite lattice constant Co (002) indicating the crystallinity of graphite is preferably 0.670 to 0.672 nm.
本発明の製造方法においては、比較的小さな粉砕応力によって原料黒鉛を加工するものであるから、高結晶性の原料黒鉛を本製造方法により製造する場合、その結晶性は全く損なわれることなく、処理後においても黒鉛格子定数Ｃｏ（００２）の値は０．６７０〜０．６７２に維持される。 In the production method of the present invention, the raw material graphite is processed by a relatively small pulverization stress. Therefore, when producing a highly crystalline raw material graphite by the present production method, its crystallinity is not impaired at all. Even later, the value of the graphite lattice constant Co (002) is maintained at 0.670 to 0.672.
リチウムイオン二次電池用負極材料、又は燃料電池用セパレータの材料として本発明黒鉛粒子を用いる場合、その平均粒子径は１００μｍ以下が好ましく、５〜５０μｍが更に好ましい。 When the graphite particles of the present invention are used as a negative electrode material for a lithium ion secondary battery or a material for a fuel cell separator, the average particle diameter is preferably 100 μm or less, more preferably 5 to 50 μm.
衝撃式粉砕機に供給する原料黒鉛を、予め５ｍｍ以下に粗粉砕しておくことにより、得られる黒鉛粒子の平均粒子径を容易に５〜５０μｍとすることができる。 By preliminarily pulverizing the raw material graphite supplied to the impact pulverizer to 5 mm or less, the average particle diameter of the obtained graphite particles can be easily adjusted to 5 to 50 μm.
黒鉛粒子の球状化の程度は、長軸と短軸との比で表すことができる。即ち、黒鉛粒子の任意の断面において、重心で直交する軸線のうち長軸／短軸の比が最大となるものを選んだときに、この長軸／短軸の比が１に近い程、真球に近いことになる。 The degree of spheroidization of the graphite particles can be expressed by the ratio between the major axis and the minor axis. That is, in an arbitrary cross section of the graphite particle, when the axis having the longest / shortest axis ratio is selected among the axes orthogonal to the center of gravity, the longer the long / short axis ratio is, the closer to 1 is true. It will be close to a sphere.
本発明の黒鉛粒子の製造方法によれば、粉砕処理の繰り返しを増すことによって、長軸／短軸の比を２以下（１〜２）とすることができる。
According to the manufacturing method of the graphite particle of the present invention, by increasing the repetition of pulverizng process, it is possible to make the ratio of the major axis /
本発明の黒鉛粒子は球状化されているため、タップ密度が大きい。鱗片状黒鉛のタップ密度が０．４〜０．７ｇ／ｃｃ程度であるのに対して、本発明の黒鉛粒子はタップ密度を０．６〜１．４ｇ／ｃｃにまで高めることができる。 Since the graphite particles of the present invention are spheroidized, the tap density is large. While the flake graphite tap density is about 0.4 to 0.7 g / cc, the graphite particles of the present invention can increase the tap density to 0.6 to 1.4 g / cc.
本発明の黒鉛粒子は、球状化されており、球状化の程度に応じて個々の粒子の異方性も低減されている。このことは、例えば、黒鉛粒子をプレスして成形体を得、この成形体にプレス方向に電気を流して比抵抗を測定すると、鱗片状の黒鉛を用いた成形体の比抵抗に対して本発明の黒鉛粒子をプレスした成形体の比抵抗は１／２乃至１／５しかないことからもわかる。 The graphite particles of the present invention are spheroidized, and the anisotropy of individual particles is reduced according to the degree of spheroidization. This is because, for example, when graphite particles are pressed to obtain a molded body, and electricity is applied to the molded body in the pressing direction and the specific resistance is measured, this is compared with the specific resistance of the molded body using scaly graphite. It can also be seen from the fact that the specific resistance of the molded body obtained by pressing the graphite particles of the invention is only 1/2 to 1/5.
従って、本発明の黒鉛粒子を使用してプレス成型体を形成した場合においても、配向が少なく、異方性の少ない成型体が得られる。 Therefore, even when a press-molded body is formed using the graphite particles of the present invention, a molded body with less orientation and less anisotropy can be obtained.
本発明黒鉛粒子をリチウムイオン二次電池用負極料材、又は燃料電池用セパレータ材料として用いる場合には、必ずしも本発明の球状化した黒鉛粒子を１００％用いる必要はない。例えば、前記の製造装置において、原料黒鉛１１に返送する粉砕黒鉛篩上粒子１６の混合割合を適宜変えることにより、得られる製品黒鉛粒子中の球状化度の高い黒鉛（長軸と短軸との比が小さい黒鉛粒子）の割合を低くした黒鉛粒子混合物を用いることも可能である。また、他の方法で粉砕した黒鉛粒子と混合して用いることも可能である。 When the graphite particles of the present invention are used as a negative electrode material for lithium ion secondary batteries or a separator material for fuel cells, it is not always necessary to use 100% of the spheroidized graphite particles of the present invention. For example, in the manufacturing apparatus, graphite having a high degree of spheroidization in the product graphite particles obtained by changing the mixing ratio of the pulverized graphite sieve particles 16 returned to the raw material graphite 11 as appropriate (with the major axis and the minor axis). It is also possible to use a graphite particle mixture in which the ratio of the graphite particles having a small ratio is low. Further, it can be used by mixing with graphite particles pulverized by other methods.
球状化した黒鉛粒子をその他の黒鉛粒子と混合して黒鉛粒子混合物にして各種用途に利用する場合、球状化した黒鉛粒子が本来具備する各種利点、作用は、黒鉛粒子組成物中の球状化した黒鉛粒子が概ね１０質量％以上存在すれば発現するので、球状化した黒鉛粒子を１０％以上含む黒鉛粒子混合物も本発明に含む。 When the spheroidized graphite particles are mixed with other graphite particles to be used as a graphite particle mixture for various purposes, the various advantages and functions inherent to the spheroidized graphite particles are spheroidized in the graphite particle composition. Since graphite particles are generally present when present in an amount of 10% by mass or more, a graphite particle mixture containing 10% or more of spheroidized graphite particles is also included in the present invention.
以下、実施例により本発明を更に具体的に説明する。 Hereinafter, the present invention will be described more specifically with reference to examples.
各物性値は以下の方法で測定した。 Each physical property value was measured by the following method.
［電気比抵抗］
断面積２ｃｍ2の塩化ビニル製パイプに銅製底蓋を取り付けて、所定量の黒鉛粒子試料をパイプ内に入れ、上方から銅製のシリンダーを挿入し、所定の圧力で前記試料をプレスした。次ぎに、プレスした試料の厚み（ｔ）をノギスで測定すると共に、試料の抵抗値（Ｒ）をアデックス社製 電気抵抗測定装置ＡＸ―１１５Ａを用いて測定した。電気比抵抗（ＳＲ）は、次式を用いて算出した。
[Electric resistivity]
A copper bottom cover was attached to a vinyl chloride pipe having a cross-sectional area of 2 cm 2 , a predetermined amount of graphite particle sample was placed in the pipe, a copper cylinder was inserted from above, and the sample was pressed at a predetermined pressure. Next, the thickness (t) of the pressed sample was measured with a vernier caliper, and the resistance value (R) of the sample was measured using an electrical resistance measuring device AX-115A manufactured by ADEX. The electrical specific resistance (SR) was calculated using the following formula.
［格子定数Ｃｏ（００２）］
（株）東芝製 Ｘ線回折装置ＸＣ―４０Ｈを用い、Ｃｕ―Ｋα線をＮｉで単色化し、高純度シリコンを標準物質として学振法により測定した。
[Lattice constant Co (002)]
Using an X-ray diffractometer XC-40H manufactured by Toshiba Corporation, Cu-Kα rays were monochromated with Ni and measured by the Gakushin method using high-purity silicon as a standard substance.
［タップ密度］
１００ｍｌのガラス製メスシリンダーに試料を入れてタッピングし、試料の容積が変化しなくなったところで試料容積を測定し、試料質量を試料容積で除した値をタップ密度とした。
[Tap density]
The sample was put into a 100 ml glass graduated cylinder and tapped. When the sample volume did not change, the sample volume was measured, and the value obtained by dividing the sample mass by the sample volume was taken as the tap density.
［平均粒子径］
（株）島津製作所製 レーザー回折式粒度測定装置ＳＡＬＤ１０００を用いて測定した。
[Average particle size]
Measurement was performed using a laser diffraction particle size analyzer SALD1000 manufactured by Shimadzu Corporation.
［粒子の外部形状］
日本電子（株）製 走査型電子顕微鏡を用いて試料の外部形状を観察した。
[External shape of particles]
The external shape of the sample was observed using a scanning electron microscope manufactured by JEOL.
［内部組織及び長軸／短軸］
ポリエステル樹脂に埋め込んだ試料を定法により研磨し、表面を薄くＡｕコーティングした後、（株）日立製作所製 電界放射型走査型電子顕微鏡Ｓ―４３００で観察し、得られる画像を（株）ニレコ製 画像解析装置ルーゼックスIIIＵで解析して測定した。
[Internal structure and long / short axis]
A sample embedded in a polyester resin is polished by a regular method, and the surface is thinly coated with Au, and then observed with a field emission scanning electron microscope S-4300 manufactured by Hitachi, Ltd. The resulting image is an image manufactured by Nireco Corporation The analysis was performed using an analyzer Luzex IIIU.
実施例１
平均粒子径３．３ｍｍの中国産黒鉛粒子を原料黒鉛とした。粉砕機として、レッチェ社製ピンミルを用いた。ローターの回転数が２００００ｒｐｍに達した後、原料黒鉛を粉砕機の吸引風に乗せて毎分２００ｇを供給した。
Example 1
Chinese graphite particles having an average particle size of 3.3 mm were used as raw material graphite. As a pulverizer, a pin mill manufactured by Lecce was used. After the rotational speed of the rotor reached 20000 rpm, the raw material graphite was placed on the suction air of the pulverizer and 200 g per minute was supplied.
回転するピンの配列は、最外周のピンが直径９．５ｃｍの位置に配列され、その線速度は約１００ｍ／秒であった。 As for the arrangement of the rotating pins, the outermost peripheral pins were arranged at a diameter of 9.5 cm, and the linear velocity was about 100 m / sec.
粉砕された黒鉛粒子は、サイクロン及びバグフィルターで捕集した。捕集した黒鉛粒子を、再び吸引風に乗せて粉砕機に毎分２００ｇで供給した。同様にして粉砕操作を合計２０回繰り返して球状の黒鉛粒子を得た。 The pulverized graphite particles were collected by a cyclone and a bag filter. The collected graphite particles were again placed on the suction air and supplied to the pulverizer at 200 g per minute. Similarly, the grinding operation was repeated 20 times in total to obtain spherical graphite particles.
得られた黒鉛粒子の物性値は次の通りであった。
平均粒子径：２５．６μｍ
タップ密度：０．９９ｇ／ｃｃ
格子定数Ｃｏ（００２）：０．６７０７ｎｍ
電気比抵抗：０．００４３Ω・ｃｍ（プレス圧力３０ＭＰａ）
得られた黒鉛粒子の外部形状を観察すると、図２に示すように球状化されていた。
The physical properties of the obtained graphite particles were as follows.
Average particle diameter: 25.6 μm
Tap density: 0.99 g / cc
Lattice constant Co (002): 0.6707 nm
Electric specific resistance: 0.0043 Ω · cm (pressing pressure 30 MPa)
When the external shape of the obtained graphite particles was observed, it was spheroidized as shown in FIG.
また、内部組織を観察して得られた電子顕微鏡写真を、図３及び図４に示す。図３は黒鉛粒子１個の全体を示す写真であり、図４はその一部拡大写真である。 In addition, FIGS. 3 and 4 show electron micrographs obtained by observing the internal structure. FIG. 3 is a photograph showing the entire graphite particle, and FIG. 4 is a partially enlarged photograph thereof.
この写真から、黒鉛粒子が褶曲した積層構造を有すること、及び概ね黒鉛粒子表面は黒鉛結晶のＡＢ面と一致していることを確認できた。長軸／短軸の比は２以下であり、１．２〜１．６のものが多く観察された。 From this photograph, it was confirmed that the graphite particles had a curved laminated structure, and that the surface of the graphite particles generally coincided with the AB surface of the graphite crystal. The ratio of major axis / minor axis was 2 or less, and many of 1.2 to 1.6 were observed.
この球状化した黒鉛粒子を用いて表１に示す条件で電極を作成し、表１に示す条件でリチウムイオン二次電池用負極材料としての評価試験を行った。その評価試験の結果を表２に示す。 An electrode was prepared using the spheroidized graphite particles under the conditions shown in Table 1, and an evaluation test as a negative electrode material for a lithium ion secondary battery was performed under the conditions shown in Table 1. The results of the evaluation test are shown in Table 2.
負荷特性は、放電速度を変えたときの放電容量で示した。 The load characteristics are indicated by the discharge capacity when the discharge rate is changed.
０．２Ｃ、１．０Ｃ、２．０Ｃ、３．０Ｃは、それぞれ、５時間、１時間、３０分、２０分で放電したことを示す。 0.2 C, 1.0 C, 2.0 C, and 3.0 C indicate that discharge was performed in 5 hours, 1 hour, 30 minutes, and 20 minutes, respectively.
比較例１
実施例１で用いた黒鉛と同じ原料黒鉛を、コンダックス社製ジェットミルを用いて粉砕した。１回の粉砕で充分に細かく粉砕されたが、粒子形状は鱗片状であり、その物性値は次の通りであった。
平均粒子径：８．７１μｍ
タップ密度：０．４７ｇ／ｃｃ
格子定数Ｃｏ（００２）：０．６７０７ｎｍ
電気比抵抗：０．０１３５Ω・ｃｍ（プレス圧力３０ＭＰａ）
実施例１と同様にして、表１に示す条件でリチウムイオン二次電池用負極材料としての評価試験を行った。その評価試験の結果を表２に示す。
Comparative Example 1
The same raw material graphite as that used in Example 1 was pulverized using a jet mill manufactured by CONDAX. Although it was sufficiently finely pulverized by one pulverization, the particle shape was scaly and the physical properties were as follows.
Average particle size: 8.71 μm
Tap density: 0.47 g / cc
Lattice constant Co (002): 0.6707 nm
Electrical specific resistance: 0.0135 Ω · cm (pressing pressure 30 MPa)
In the same manner as in Example 1, an evaluation test as a negative electrode material for a lithium ion secondary battery was performed under the conditions shown in Table 1. The results of the evaluation test are shown in Table 2.
実施例１の球状化した黒鉛粒子は、比較例１の鱗片状黒鉛粒子と比較して、次のように評価することができる。 The spheroidized graphite particles of Example 1 can be evaluated as follows in comparison with the flaky graphite particles of Comparative Example 1.
実施例１の黒鉛粒子は、その内部組織観察から、積層構造が褶曲していることが確認され、個々の粒子の異方性が少なくなっている。 From the observation of the internal structure of the graphite particles of Example 1, it is confirmed that the laminated structure is bent, and the anisotropy of individual particles is reduced.
また、外部形状の観察から、及びタップ密度が高いこと、更に長軸／短軸の比が小さいことから、球状化されていることが認められる。従って、本発明の球状化した黒鉛粒子を用いて形成した成型体は、配向を生じ難い。 Moreover, it is recognized from the observation of the external shape, that the tap density is high, and that the ratio of the major axis / minor axis is small, and that it is spheroidized. Therefore, the molded body formed using the spheroidized graphite particles of the present invention is less likely to be oriented.
実際、上記のように、実施例１でプレスした黒鉛粒子の電気比抵抗値は、比較例１でプレスした鱗片状黒鉛粒子の電気比抵抗値の１／３以下である。 Actually, as described above, the electrical resistivity value of the graphite particles pressed in Example 1 is 1/3 or less of the electrical resistivity value of the scaly graphite particles pressed in Comparative Example 1.
更に、球状化した黒鉛粒子をリチウムイオン二次電池用負極材として使用した場合には、高速放電の場合でも放電容量の低下が少ない。これは負極に形成した黒鉛層の異方性が少なくなり、黒鉛層の厚さ方向の導電性が高くなったことを示す。 Furthermore, when the spheroidized graphite particles are used as a negative electrode material for a lithium ion secondary battery, the decrease in discharge capacity is small even in the case of high-speed discharge. This indicates that the anisotropy of the graphite layer formed on the negative electrode is reduced, and the conductivity in the thickness direction of the graphite layer is increased.
実施例２
平均粒子径０．３ｍｍのブラジル産黒鉛粒子を原料黒鉛として用いた。粉砕機は、実施例１で使用したレッチェ社製ピンミルのローターをピンローターから三角歯を有するエッジローターに取替えたものであった。
Example 2
Brazilian graphite particles having an average particle diameter of 0.3 mm were used as raw material graphite. The crusher was obtained by replacing the pin mill rotor manufactured by Lecce, which was used in Example 1, with an edge rotor having triangular teeth from the pin rotor.
三角歯は、エッジを中心に向け、最外周部の間隔を２ｍｍ隙間で同心円状に配列されており、最外周の直径は８．０ｃｍであった。また、通常の粉砕では、ローターの外周に近接してストレーナーを設置するが、この場合は取付けなかった。 The triangular teeth were arranged concentrically with the edge at the center and the outermost peripheral part spaced by 2 mm, and the outermost peripheral diameter was 8.0 cm. In normal grinding, a strainer is installed close to the outer periphery of the rotor, but in this case, it was not attached.
また、供給口と排出口とをパイプで接続した。これにより、ローターの回転によって生じる気流が、排出口からパイプを介して再び供給口に戻り、循環して流れることになる。この結果、原料黒鉛は気流と共に粉砕機とパイプとを循環して流れることになり、繰返し粉砕が行われる。 Moreover, the supply port and the discharge port were connected by a pipe. As a result, the air flow generated by the rotation of the rotor returns from the discharge port to the supply port via the pipe, and circulates. As a result, the raw graphite flows through the pulverizer and the pipe together with the air current, and is repeatedly pulverized.
粉砕処理は、原料黒鉛１５０ｇを粉砕機に投入し、回転数１００００ｒｐｍで６０秒間行った。 The grinding process was performed for 60 seconds at a rotational speed of 10000 rpm by putting 150 g of raw material graphite into a grinding machine.
得られた黒鉛粒子の物性値は次に示す通りであった。 The physical properties of the obtained graphite particles were as follows.
平均粒子径： ２０．３μｍ
タップ密度： １．０２ｇ／ｃｃ
格子定数Ｃｏ（００２）： ０．６７０８ｎｍ
電気比抵抗： ０．００４５Ω・ｃｍ（プレス圧力３０ＭＰａ）
また、内部組織を観察して得られた電子顕微鏡写真を図５、６に示す。実施例１と同様に、黒鉛粒子が褶曲した積層構造を有すること、及び概ね黒鉛粒子表面は黒鉛結晶のＡＢ面と一致していることを確認した。長軸／短軸の比は２以下であり、１．２〜１．７のものが多く観察された。
Average particle size: 20.3 μm
Tap density: 1.02 g / cc
Lattice constant Co (002): 0.6708 nm
Electric specific resistance: 0.0045 Ω · cm (pressing pressure 30 MPa)
In addition, FIGS. 5 and 6 show electron micrographs obtained by observing the internal structure. In the same manner as in Example 1, it was confirmed that the graphite particles had a curved laminated structure, and that the surface of the graphite particles substantially coincided with the AB surface of the graphite crystal. The ratio of major axis / minor axis was 2 or less, and many of 1.2 to 1.7 were observed.
応用例１
実施例１で得られた球状化した黒鉛粒子４００ｇと、群栄化学工業社製ノボラック型フェノール樹脂２００ｇ（溶融開始温度９５℃）を、三井鉱山（株）製 ヘンシェルミキサー１０Ｂ型に投入し、撹拌翼を３２００ｒｐｍで１０分間回転させ、混合及び混練を行った。この間に、試料温度は室温から１２０℃まで上昇した。
Application example 1
400 g of the spheroidized graphite particles obtained in Example 1 and 200 g of novolak-type phenol resin (melting start temperature 95 ° C.) manufactured by Gunei Chemical Industry Co., Ltd. are charged into a Henschel mixer 10B type manufactured by Mitsui Mining Co., Ltd. and stirred. The blade was rotated at 3200 rpm for 10 minutes to perform mixing and kneading. During this time, the sample temperature rose from room temperature to 120 ° C.
その後、冷却すると共にミキサーの回転数を１６００ｒｐｍまで下げて、１１０℃で２分間撹拌することにより、平均粒径約１００μｍの造粒物を得た。 Thereafter, the mixture was cooled and the rotational speed of the mixer was lowered to 1600 rpm, followed by stirring at 110 ° C. for 2 minutes to obtain a granulated product having an average particle diameter of about 100 μm.
この造粒物を小平製作所製 プレス機ＰＹ―５０ＥＡを用いて、２００℃、１０ＭＰａで成型し、１２０ｘ１００ｘ１ｍｍの燃料電池セパレータ用成型体を得た。成型体の密度は２．００ｇ／ｃｃ、ＪＩＳ Ｋ６９１１−１９７９法による３点曲げ強度は６２ＭＰａ、接触抵抗は２．０ｍΩ・ｃｍ2、ヘリウムリーク量なしであった。 This granulated product was molded at 200 ° C. and 10 MPa using a press machine PY-50EA manufactured by Kodaira Seisakusho to obtain a molded body for a fuel cell separator of 120 × 100 × 1 mm. The density of the molded body was 2.00 g / cc, the three-point bending strength according to JIS K6911-1979 method was 62 MPa, the contact resistance was 2.0 mΩ · cm 2 , and there was no helium leak.
尚、接触抵抗は、成型体を電極で挟んで通電したときの、単位断面積当りの抵抗値を示し、電極との接触抵抗を含む厚み方向の抵抗値である。 The contact resistance indicates a resistance value per unit cross-sectional area when the molded body is sandwiched between electrodes, and is a resistance value in the thickness direction including the contact resistance with the electrode.
比較応用例１
比較例１で得られた鱗片状黒鉛を用いて、応用例１と同様の方法で燃料電池セパレータ用成型体を得た。
Comparative application example 1
Using the scaly graphite obtained in Comparative Example 1, a molded article for a fuel cell separator was obtained in the same manner as in Application Example 1.
成型体の密度は１．９５ｇ／ｃｃ、３点曲げ強度は６３ＭＰａ、接触抵抗は１０．８ｍΩ・ｃｍ2、ヘリウムリーク量なしであった。 The density of the molded body was 1.95 g / cc, the three-point bending strength was 63 MPa, the contact resistance was 10.8 mΩ · cm 2 , and there was no helium leak.
実施例２と比較例２の成形体の測定値を比較すると、本発明の球状化した黒鉛粒子を用いて燃料電池セパレータ用成型体を製造した場合には、この成形体は高い成型体密度と曲げ強度、及びガスシールド性を保ちつつ、高い電気導電性を有することが示される。 When the measured values of the molded bodies of Example 2 and Comparative Example 2 are compared, when the molded body for a fuel cell separator is produced using the spheroidized graphite particles of the present invention, this molded body has a high molded body density. It shows that it has high electrical conductivity while maintaining bending strength and gas shielding properties.
１ 定量供給機
２ 衝撃式粉砕機
３ バグフィルター
４ 篩
５ 分級機
１１ 原料黒鉛
１２ 空気
１３ 空気
１４ 空気
１５ 粉砕黒鉛
１６ 粉砕黒鉛篩上粒子
１７ 粉砕黒鉛篩下粒子
１８ 球状黒鉛粒子
１９ 過粉砕された黒鉛微粒子
DESCRIPTION OF
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007197361A JP4143108B2 (en) | 2007-07-30 | 2007-07-30 | Graphite particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2007197361A JP4143108B2 (en) | 2007-07-30 | 2007-07-30 | Graphite particles |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006342804A Division JP4076566B2 (en) | 2006-12-20 | 2006-12-20 | Method for producing graphite particles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008024588A JP2008024588A (en) | 2008-02-07 |
| JP4143108B2 true JP4143108B2 (en) | 2008-09-03 |
Family
ID=39115604
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2007197361A Expired - Fee Related JP4143108B2 (en) | 2007-07-30 | 2007-07-30 | Graphite particles |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4143108B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011125577A1 (en) | 2010-03-31 | 2011-10-13 | 住友金属工業株式会社 | Modified natural graphite particle and method for producing same |
| CN103596881A (en) | 2011-04-08 | 2014-02-19 | 中央电气工业株式会社 | Modified natural graphite particles |
| GB201405614D0 (en) * | 2014-03-28 | 2014-05-14 | Perpetuus Res & Dev Ltd | Particles |
| JP6649108B2 (en) * | 2016-02-15 | 2020-02-19 | 大同メタル工業株式会社 | Sliding device |
| JP6300843B2 (en) | 2016-02-15 | 2018-03-28 | 大同メタル工業株式会社 | Sliding member |
| JP6298132B1 (en) | 2016-09-23 | 2018-03-20 | 大同メタル工業株式会社 | Sliding member |
| CN112110444A (en) * | 2020-09-15 | 2020-12-22 | 广东东岛新能源股份有限公司 | Spherical graphite production process flow and production system thereof |
| KR102604724B1 (en) * | 2021-12-17 | 2023-11-22 | 포스코홀딩스 주식회사 | Method for manufacuturing negative electrode material for secondary batteries |
-
2007
- 2007-07-30 JP JP2007197361A patent/JP4143108B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2008024588A (en) | 2008-02-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4143108B2 (en) | Graphite particles | |
| JP2002348110A (en) | Graphite particle and method for producing the same | |
| CN105340109B (en) | Electrode material and its purposes in lithium ion battery | |
| JP7028354B2 (en) | All-solid-state lithium-ion secondary battery | |
| JP3635044B2 (en) | Negative electrode material for lithium secondary battery, method for producing the same, and lithium secondary battery | |
| KR101421860B1 (en) | Modified natural graphite particle and method for producing same | |
| JP6777989B2 (en) | A method for producing lithium ion conductive sulfide, the lithium ion conductive sulfide produced thereby, a solid electrolyte containing the same, and an all-solid-state battery. | |
| JP4065136B2 (en) | Method for producing spheroidized graphite particles | |
| CN107768669B (en) | Spherical graphite and preparation method thereof | |
| TWI648899B (en) | Powder, electrode containing the powder, and battery pack | |
| JP7101821B2 (en) | Silicon-carbon composite material, its manufacturing method and use | |
| WO2011033731A1 (en) | Silicon oxide, and negative electrode material for lithium ion secondary battery | |
| JP6030995B2 (en) | Anode material for non-aqueous electrolyte secondary battery, method for producing the same, and lithium ion secondary battery | |
| WO2020043131A1 (en) | Spherical graphite used for lithium batteries and preparation method therefor | |
| JP4076566B2 (en) | Method for producing graphite particles | |
| CN114829302B (en) | Silicon microparticles and method for producing same | |
| KR20080037536A (en) | Positive electrode active material for lithium ion secondary battery and process for preparing the same | |
| JP6434125B2 (en) | Molded product containing transition metal polysulfide, battery electrode, and method for producing the same | |
| WO2022045302A1 (en) | Active material, method for producing same, electrode mixture and battery | |
| CN110380109A (en) | The manufacturing method of sulfide solid electrolyte particle | |
| JP3597099B2 (en) | Consolidated graphite particles, method for producing the same, and negative electrode material for lithium secondary battery | |
| WO2014057909A1 (en) | Carbon material for electricity storage device, process for manufacturing same, and electricity storage device using same | |
| AU6558601A (en) | Powder of electrolytic manganese dioxide and process for producing the same | |
| JP2014086237A (en) | Method of producing graphite powder for negative electrode material of lithium secondary battery | |
| JP2975516B2 (en) | Positive electrode active material for dry batteries and alkaline dry batteries |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080108 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080305 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080603 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080613 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110620 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4143108 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110620 Year of fee payment: 3 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110620 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120620 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130620 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: R3D02 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |