JP6905159B1 - Method for manufacturing graphite material - Google Patents
Method for manufacturing graphite material Download PDFInfo
- Publication number
- JP6905159B1 JP6905159B1 JP2020568829A JP2020568829A JP6905159B1 JP 6905159 B1 JP6905159 B1 JP 6905159B1 JP 2020568829 A JP2020568829 A JP 2020568829A JP 2020568829 A JP2020568829 A JP 2020568829A JP 6905159 B1 JP6905159 B1 JP 6905159B1
- Authority
- JP
- Japan
- Prior art keywords
- graphite material
- mass
- crushing
- producing
- less
- 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.)
- Active
Links
- 239000007770 graphite material Substances 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title claims description 27
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 23
- 238000005087 graphitization Methods 0.000 claims abstract description 23
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 23
- 239000010703 silicon Substances 0.000 claims abstract description 23
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000007773 negative electrode material Substances 0.000 claims abstract description 16
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 15
- 238000010298 pulverizing process Methods 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 38
- 239000011148 porous material Substances 0.000 claims description 5
- 238000004438 BET method Methods 0.000 claims description 4
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 4
- 229910052753 mercury Inorganic materials 0.000 claims description 4
- 239000004005 microsphere Substances 0.000 abstract description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 17
- 229910002804 graphite Inorganic materials 0.000 description 16
- 239000010439 graphite Substances 0.000 description 16
- 239000000203 mixture Substances 0.000 description 13
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 12
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 10
- 239000000377 silicon dioxide Substances 0.000 description 10
- 235000012239 silicon dioxide Nutrition 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 238000011156 evaluation Methods 0.000 description 8
- 239000008151 electrolyte solution Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 239000011295 pitch Substances 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 238000007600 charging Methods 0.000 description 6
- 239000003921 oil Substances 0.000 description 6
- 239000011269 tar Substances 0.000 description 6
- 230000002093 peripheral effect Effects 0.000 description 5
- 101100327917 Caenorhabditis elegans chup-1 gene Proteins 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 239000011294 coal tar pitch Substances 0.000 description 4
- 239000011888 foil Substances 0.000 description 4
- 239000011889 copper foil Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052744 lithium Inorganic materials 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229910021382 natural graphite Inorganic materials 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Chemical compound C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 description 2
- 229910021383 artificial graphite Inorganic materials 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000003575 carbonaceous material Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000010280 constant potential charging Methods 0.000 description 2
- 238000010277 constant-current charging Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000011302 mesophase pitch Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000002641 tar oil Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- 229910013870 LiPF 6 Inorganic materials 0.000 description 1
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000002134 carbon nanofiber Substances 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000011280 coal tar Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000009838 combustion analysis Methods 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000009396 hybridization Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 150000002506 iron compounds Chemical class 0.000 description 1
- 235000014413 iron hydroxide Nutrition 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000011802 pulverized particle Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000010421 standard material Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000003981 vehicle Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/14—Pore volume
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Electrochemistry (AREA)
- Geology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
本発明は、リチウムイオン二次電池用負極材料として高い電極密度、高い放電容量、優れた急速充放電特性が得られ、工業的にも簡便かつ安価な黒鉛材料を製造方法を提供する。本発明の黒鉛材料の製造方法は、メソフェーズ小球体焼成物を粉砕する粉砕工程と、前記粉砕工程で得られた粉砕物を、珪素元素および鉄元素の存在下で黒鉛化する黒鉛化工程と、前記黒鉛化工程で得られた黒鉛化物を解砕する解砕工程からなる。The present invention provides a method for producing a graphite material that is industrially simple and inexpensive because it can obtain high electrode density, high discharge capacity, and excellent rapid charge / discharge characteristics as a negative electrode material for a lithium ion secondary battery. The method for producing a graphite material of the present invention includes a pulverization step of crushing a mesophase microsphere calcined product, a graphitization step of graphitizing the pulverized product obtained in the pulverization step in the presence of silicon element and iron element. It comprises a crushing step of crushing the graphitized product obtained in the graphitization step.
Description
本発明は、黒鉛材料の製造方法に関する。 The present invention relates to a method for producing a graphite material.
リチウムイオン二次電池は、他の二次電池に比べて高電圧、高エネルギー密度という優れた特性を有することから、電池機器の電源として広く普及している。近年では、リチウムイオン二次電池が車載用に用いられるようになり、急速充放電特性やサイクル特性が従来以上に重要になっている。 Lithium-ion secondary batteries have excellent characteristics of high voltage and high energy density as compared with other secondary batteries, and are therefore widely used as power sources for battery devices. In recent years, lithium-ion secondary batteries have come to be used in vehicles, and rapid charge / discharge characteristics and cycle characteristics have become more important than before.
上記のリチウムイオン二次電池の負極材料には、通常炭素材料が使用される。その中でも黒鉛は、充放電特性に優れ高い放電容量と電位平坦性を示すことから広く用いられている。負極材料として使用される黒鉛としては、天然黒鉛、人造黒鉛などの黒鉛粒子、タール、ピッチを原料としたメソフェーズピッチやメソフェーズ小球体を熱処理して得られるバルクメソフェーズ黒鉛質粒子やメソフェーズ小球体黒鉛質粒子、粒子状や繊維状のメソフェーズピッチを酸化不融化した後に熱処理して得られるメソフェーズ黒鉛質粒子やメソフェーズ黒鉛質繊維、さらには、天然黒鉛や人造黒鉛をタール、ピッチなどで被覆した後に熱処理して得られる複合黒鉛質粒子などがあげられる。 A carbon material is usually used as the negative electrode material of the above-mentioned lithium ion secondary battery. Among them, graphite is widely used because it has excellent charge / discharge characteristics and exhibits high discharge capacity and potential flatness. As the graphite used as the negative electrode material, bulk mesophase graphite particles and mesophase small sphere graphite obtained by heat-treating mesophase pitch and mesophase small spheres made from natural graphite, graphite particles such as artificial graphite, tar, and pitch. Mesophase graphite particles and mesophase graphite fibers obtained by heat treatment after oxidative insolubilization of particles, particle-like or fibrous mesophase pitch, and further, natural graphite or artificial graphite is coated with tar, pitch, etc. and then heat-treated. Examples thereof include composite graphite particles obtained.
これらの黒鉛材料の中でも特にメソフェーズ小球体黒鉛質粒子は、粒子内の結晶構造がランダムな方向に発達していることから、電極密度を向上させた際に集電体に対して平行に配向しづらく、サイクル特性に優れるという特徴がある。一方で、天然黒鉛と比較すると結晶性が低く、放電容量は小さい。またメソフェーズ小球体黒鉛質粒子は形状が球状であるため、粒子間の接点に乏しく、急速充放電特性が劣る傾向にある。 Among these graphite materials, mesophase microspherical graphite particles are oriented parallel to the current collector when the electrode density is improved because the crystal structure in the particles develops in random directions. It is difficult to use and has excellent cycle characteristics. On the other hand, it has lower crystallinity and smaller discharge capacity than natural graphite. Further, since the mesophase microspherical graphite particles have a spherical shape, they tend to have poor contact points between the particles and have poor rapid charge / discharge characteristics.
そこで、メソフェーズ小球体黒鉛質粒子の放電容量および急速充放電特性を向上させるための試みがこれまでにもなされている。 Therefore, attempts have been made to improve the discharge capacity and rapid charge / discharge characteristics of mesophase microspherical graphite particles.
放電容量に関しては、鉄、アルミニウム、ニッケル、コバルト、珪素などの金属また金属化合物を黒鉛化触媒として添加することで、黒鉛化度を高める方法が知られている。例えば特許文献1では、黒鉛化触媒として鉄元素と珪素元素を特定の比率で使用することで、放電容量を特に高められる技術が開示されている。しかしながら、急速充放電特性への効果は明らかでない。
Regarding the discharge capacity, a method of increasing the degree of graphitization by adding a metal such as iron, aluminum, nickel, cobalt, or silicon or a metal compound as a graphitization catalyst is known. For example,
また、急速充放電特性を向上させる技術としては、気相成長炭素繊維などの導電材を、黒鉛材料に配合ないし複合化して用いる手法が知られている(特許文献2)。しかしながら導電材自身の放電容量や初期充放電効率は黒鉛材料に比べて低いものであるため、添加量に応じてこれらの特性が低下する。すなわち、放電容量と急速充放電特性は従来技術では両立が困難である。 Further, as a technique for improving the rapid charge / discharge characteristics, a method of blending or compounding a conductive material such as a vapor-grown carbon fiber with a graphite material is known (Patent Document 2). However, since the discharge capacity and the initial charge / discharge efficiency of the conductive material itself are lower than those of the graphite material, these characteristics deteriorate depending on the amount of addition. That is, it is difficult to achieve both discharge capacity and rapid charge / discharge characteristics with the prior art.
また、特許文献3では、黒鉛化によって生じる微小隆起物を機械的エネルギーにより脱落させ、さらに分離することで、急速充放電特性に優れた微小黒鉛質粒子を得る方法が開示されている。しかしながら、このような微粒子は電極をプレスした際に密度が上がりづらく、エネルギー密度を向上できない問題がある。またこの方法では分離工程の収率が極めて低く、工業的に実用できるものではない。
Further,
本発明は上記のような状況を鑑みてなされたものであり、リチウムイオン二次電池用負極材料として高い電極密度、高い放電容量、優れた急速充放電特性が得られ、工業的にも簡便かつ安価な黒鉛材料の製造方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and can provide high electrode density, high discharge capacity, and excellent rapid charge / discharge characteristics as a negative electrode material for a lithium ion secondary battery, and is industrially simple. An object of the present invention is to provide an inexpensive method for producing a graphite material.
本発明は、以下の[1]〜[5]を提供する。
[1]メソフェーズ小球体焼成物を粉砕する粉砕工程と、
前記粉砕工程で得られた粉砕物を、珪素元素および鉄元素の存在下で黒鉛化する黒鉛化工程と、
前記黒鉛化工程で得られた黒鉛化物を解砕する解砕工程からなる黒鉛材料の製造方法であって、
前記粉砕物の平均粒子径が10μm以上、15μm以下であり、
前記黒鉛材料の平均粒子径が10μm以上、15μm以下である黒鉛材料の製造方法。
[2]前記珪素元素の添加量が前記粉砕物100質量部に対し1質量部以上、5質量部以下であり、
前記鉄元素の添加量が前記粉砕物100質量部に対し1質量部以上、5質量部以下である[1]に記載の黒鉛材料の製造方法。
[3]前記解砕工程がメカノケミカル処理からなる[1]または[2]に記載の黒鉛材料の製造方法。
[4]前記黒鉛材料のd 002が0.3360nm以下、BET法による比表面積が3m2/g以上、水銀圧入法で測定される0.1μm未満の細孔容積が10μL/g以上である[1]〜[3]のいずれかに記載の黒鉛材料の製造方法。
[5]前記黒鉛材料がリチウムイオン二次電池の負極材料である[1]〜[4]のいずれかに記載の黒鉛材料の製造方法。
The present invention provides the following [1] to [ 5 ].
[1] A crushing step of crushing a mesophase small sphere fired product and
A graphitization step of graphitizing the pulverized product obtained in the pulverization step in the presence of silicon element and iron element,
A method for producing a graphite material, which comprises a crushing step of crushing the graphitized product obtained in the graphitization step.
The average particle size of the pulverized product is 10 μm or more and 15 μm or less.
A method for producing a graphite material, wherein the average particle size of the graphite material is 10 μm or more and 15 μm or less .
[ 2 ] The amount of the silicon element added is 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pulverized product.
The method for producing a graphite material according to [1], wherein the amount of the iron element added is 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pulverized product.
[ 3 ] The method for producing a graphite material according to [1] or [2] , wherein the crushing step comprises a mechanochemical treatment.
[ 4 ] The d 002 of the graphite material is 0.3360 nm or less, the specific surface area by the BET method is 3 m 2 / g or more, and the pore volume of less than 0.1 μm measured by the mercury intrusion method is 10 μL / g or more [ 1] The method for producing a graphite material according to any one of [3].
[ 5 ] The method for producing a graphite material according to any one of [1] to [4 ], wherein the graphite material is a negative electrode material for a lithium ion secondary battery.
本発明の製造方法によれば、リチウムイオン二次電池用負極材料として高い電極密度、高い放電容量、優れた急速充放電特性を示す黒鉛材料を工業的にも簡便かつ安価に得ることができ、近年の二次電池に対する急速充放電特性の要求を満たすことができる。 According to the manufacturing method of the present invention, a graphite material exhibiting high electrode density, high discharge capacity, and excellent rapid charge / discharge characteristics can be obtained industrially easily and inexpensively as a negative electrode material for a lithium ion secondary battery. It is possible to meet the demand for rapid charge / discharge characteristics of recent secondary batteries.
以下、本発明について具体的に説明する。 Hereinafter, the present invention will be specifically described.
(メソフェーズ小球体)
本発明の出発原料であるメソフェーズ小球体は、フリーカーボンを0.01〜2質量%、好ましくは0.3〜0.9質量%含有する石油系または石炭系のタールピッチ類を、350〜1000℃、好ましくは400〜600℃、より好ましくは400〜450℃で熱処理して得ることができる。該ピッチ類としては、コールタール、タール軽油、タール中油、タール重油、ナフタリン油、アントラセン油、コールタールピッチ、ピッチ油、酸素架橋石油ピッチ、ヘビーオイルなどが挙げられるが、コールタールピッチが好ましい。(Mesophase small sphere)
The mesophase globules, which are the starting materials of the present invention, contain 350 to 1000 petroleum-based or coal-based tar pitches containing 0.01 to 2% by mass, preferably 0.3 to 0.9% by mass of free carbon. It can be obtained by heat treatment at ° C., preferably 400 to 600 ° C., more preferably 400 to 450 ° C. Examples of the pitches include coal tar, tar light oil, tar medium oil, tar heavy oil, naphthaline oil, anthracene oil, coal tar pitch, pitch oil, oxygen-bridged oil pitch, heavy oil and the like, but coal tar pitch is preferable.
メソフェーズ小球体の平均粒径は、20〜70μm、好ましくは30〜50μmである。粒径が20μmより小さい場合、放電容量の向上効果が不十分となることがある。 The average particle size of the mesophase globules is 20 to 70 μm, preferably 30 to 50 μm. If the particle size is smaller than 20 μm, the effect of improving the discharge capacity may be insufficient.
(焼成)
メソフェーズ小球体は、不活性雰囲気下で400〜800℃で、1〜6時間加熱して、焼成し、メソフェーズ小球体焼成物とする。メソフェーズ小球体焼成物とすることにより黒鉛化時の融着を防ぐことができる。(Baking)
The mesophase microspheres are fired by heating at 400 to 800 ° C. for 1 to 6 hours in an inert atmosphere to obtain a mesophase microsphere calcined product. By using a mesophase small sphere calcined product, fusion during graphitization can be prevented.
(粉砕)
本発明のメソフェーズ小球体焼成物を粉砕する工程においては、粉砕の方法は特に限定されず、乾式法、湿式法のいずれも用いることができるが、乾式法が好ましい。粉砕後の平均粒径は10〜15μmであることが好ましい。また、平均粒径を調整するために分級を行っても差し支えない。(Crushing)
In the step of crushing the mesophase small sphere fired product of the present invention, the crushing method is not particularly limited, and either a dry method or a wet method can be used, but the dry method is preferable. The average particle size after pulverization is preferably 10 to 15 μm. Further, classification may be performed in order to adjust the average particle size.
(珪素元素および鉄元素)
本発明における珪素元素および鉄元素は、これらの元素単体のみならず珪素化合物および鉄化合物を含む。また、後述する黒鉛化工程において蒸発するものであれば、他の金属元素を含んでいても合金の形態であってもかまわない。好ましくは、酸化珪素、炭化珪素、酸化鉄、水酸化鉄、フェロシリコンである。
珪素元素および鉄元素は粉状であることが好ましく、その平均粒径は5μm以下であることが好ましく、1μm以下であることがさらに好ましい。(Silicon element and iron element)
The silicon element and the iron element in the present invention include not only these element elements but also silicon compounds and iron compounds. Further, as long as it evaporates in the graphitization step described later, it may contain other metal elements or may be in the form of an alloy. Preferred are silicon oxide, silicon carbide, iron oxide, iron hydroxide and ferrosilicon.
The silicon element and the iron element are preferably in the form of powder, and the average particle size thereof is preferably 5 μm or less, and more preferably 1 μm or less.
珪素元素および鉄元素の添加量は、メソフェーズ小球体焼成物の粉砕物100質量部に対して、元素単体に換算してそれぞれ1〜5質量部であることが好ましい。1質量部未満では本発明の効果が十分に得られないことがある。5質量部超では黒鉛化工程において黒鉛材料が融着し、電池特性が低下することがある。 The amount of the silicon element and the iron element added is preferably 1 to 5 parts by mass in terms of elemental substances with respect to 100 parts by mass of the pulverized product of the mesophase small sphere fired product. If it is less than 1 part by mass, the effect of the present invention may not be sufficiently obtained. If it exceeds 5 parts by mass, the graphite material may be fused in the graphitization step, and the battery characteristics may be deteriorated.
珪素元素および鉄元素は、黒鉛化前にメソフェーズ小球体焼成物の粉砕物と均一に混合しておくことが好ましい。混合の方法は特に限定されず、攪拌式、回転式、風力式など公知の混合機を用いることができる。また、粉砕工程の前にメソフェーズ小球体焼成物、珪素元素、鉄元素を混合しておき、粉砕と混合を同時に実施することも可能である。 It is preferable that the silicon element and the iron element are uniformly mixed with the pulverized mesophase microsphere calcined product before graphitization. The mixing method is not particularly limited, and a known mixer such as a stirring type, a rotary type, or a wind type can be used. It is also possible to mix the mesophase small sphere fired product, silicon element, and iron element before the crushing step, and crush and mix at the same time.
(黒鉛化)
本発明における黒鉛化は、例えばアチソン炉など公知の高温炉を用いて熱処理する方法が採用できる。これにより珪素元素および鉄元素は分解・蒸発するため、得られる黒鉛材料には実質的に残存しない。熱処理温度は、珪素元素および鉄元素が蒸発する温度以上であることは言うまでもないが、具体的には2500℃以上、好ましくは3000℃以上、より好ましくは3100℃以上である。上限は3300℃である。黒鉛化は非酸化性雰囲気で行うことが好ましい。黒鉛化に要する時間は一概には言えないが、1〜20時間程度である。
なお黒鉛化後に珪素元素または鉄元素が残存しているかどうかは、一般的な燃焼分析によって確かめることができ、灰分として0.03質量%未満であることが好ましく、0.01質量%未満であることがさらに好ましい。(Graphitization)
For graphitization in the present invention, a method of heat treatment using a known high-temperature furnace such as an Atison furnace can be adopted. As a result, the silicon element and the iron element are decomposed and evaporated, so that they do not substantially remain in the obtained graphite material. Needless to say, the heat treatment temperature is equal to or higher than the temperature at which the silicon element and the iron element evaporate, but specifically, it is 2500 ° C. or higher, preferably 3000 ° C. or higher, and more preferably 3100 ° C. or higher. The upper limit is 3300 ° C. Graphitization is preferably performed in a non-oxidizing atmosphere. The time required for graphitization cannot be unequivocally determined, but it is about 1 to 20 hours.
Whether or not silicon element or iron element remains after graphitization can be confirmed by general combustion analysis, and the ash content is preferably less than 0.03% by mass, more preferably less than 0.01% by mass. Is even more preferable.
(解砕)
本発明は、黒鉛化物を解砕する工程を含む。これは、黒鉛化工程において珪素元素が炭素材料と反応して黒鉛粒子同士が融着するため、再び一次粒子にまで分離する必要があるためである。解砕後の平均粒径は、黒鉛化前の平均粒径に比して0.9〜1.0の範囲であることが好ましい。平均粒径の比が0.9未満であると、過粉砕となり、初期充放電効率が低下することがある。平均粒径の比が1.0超であると、解砕が不十分となり、電極密度が低下することがある。(Crushing)
The present invention includes a step of crushing the graphitized product. This is because the silicon element reacts with the carbon material in the graphitization step and the graphite particles are fused to each other, so that it is necessary to separate the graphite particles into primary particles again. The average particle size after crushing is preferably in the range of 0.9 to 1.0 as compared with the average particle size before graphitization. If the ratio of the average particle size is less than 0.9, over-grinding may occur and the initial charge / discharge efficiency may decrease. If the ratio of the average particle size is more than 1.0, the crushing may be insufficient and the electrode density may decrease.
解砕の方法は、上述した平均粒径を実現できるものであれば特に限定されず、ハンマーミル、攪拌ミル、ジェットミル、ボールミル、ビーズミルなど公知の粉砕機を用いることができる。好ましくは、ハイブリダイゼーションシステム((株)奈良機械製作所)、メカノフュージョンシステム(ホソカワミクロン(株))、ノビルタ(ホソカワミクロン(株))、乾式アトライタ(日本コークス工業(株))などのメカノケミカル処理機(剪断圧縮処理機)を用いる方法が挙げられる。 The crushing method is not particularly limited as long as it can achieve the above-mentioned average particle size, and a known crusher such as a hammer mill, a stirring mill, a jet mill, a ball mill, or a bead mill can be used. Preferably, a mechanochemical processing machine such as a hybridization system (Nara Kikai Seisakusho Co., Ltd.), a mechanofusion system (Hosokawa Micron Co., Ltd.), Nobilta (Hosokawa Micron Co., Ltd.), and a dry attritor (Nippon Coke Industries Co., Ltd.) ( A method using a shear compression processor) can be mentioned.
(黒鉛材料)
本発明の製造方法により得られる黒鉛材料(以下、単に本発明の黒鉛材料と記述する)は高結晶性であり、光学的異方性を示す。黒鉛の結晶性は、X線広角回折における(002)面の平均格子面間隔d002を指標とすることができ、本発明の黒鉛材料については、d002が0.3360nm以下であることが好ましく、0.3358nm以下であることがさらに好ましい。d002が0.3360nm超であると、高い放電容量が得られないことがある。(Graphite material)
The graphite material obtained by the production method of the present invention (hereinafter, simply referred to as the graphite material of the present invention) has high crystallinity and exhibits optical anisotropy. The crystallinity of graphite can be indexed by the average lattice spacing d 002 of the (002) plane in X-ray wide-angle diffraction, and for the graphite material of the present invention, d 002 is preferably 0.3360 nm or less. , 0.3358 nm or less, more preferably. If d 002 is more than 0.3360 nm, a high discharge capacity may not be obtained.
ここでX線広角回折における(002)面の平均格子面間隔d002とは、X線としてCuKα線を用い、高純度シリコンを標準物質に使用して黒鉛材料の(002)面の回折ピークを測定し、そのピークの位置から算出する。算出方法は、学振法(日本学術振興会第17委員会が定めた測定法)に従うものであり、具体的には「炭素繊維」[大谷杉郎、733−742頁(1986年3月)、近代編集社]に記載された方法によって測定された値である。 Here, the average lattice spacing d 002 of the (002) plane in X-ray wide-angle diffraction is the diffraction peak of the (002) plane of the graphite material using CuKα rays as X-rays and high-purity silicon as a standard material. Measure and calculate from the position of the peak. The calculation method follows the Gakushin method (measurement method established by the 17th Committee of the Japan Society for the Promotion of Science), specifically "carbon fiber" [Sugio Otani, pp. 733-742 (March 1986)). , Modern editorial company].
また、本発明の黒鉛材料は多孔性であり、リチウムイオン二次電池の負極材料として優れた急速充放電特性を示す。本発明の黒鉛材料のBET法による比表面積は3m2/g以上であることが好ましい。上限は5m2/gが好ましい。
また、水銀圧入法により測定される0.1μm未満の細孔の容積は10μL/g以上であることが好ましい。上限は20μL/gが好ましい。比表面積が3m2/g未満であるか、0.1μm未満の細孔の容積が10μL/g未満である場合には急速充放電特性が低下することがある。Further, the graphite material of the present invention is porous and exhibits excellent rapid charge / discharge characteristics as a negative electrode material for a lithium ion secondary battery. The specific surface area of the graphite material of the present invention by the BET method is preferably 3 m 2 / g or more. The upper limit is preferably 5 m 2 / g.
Further, the volume of pores less than 0.1 μm measured by the mercury intrusion method is preferably 10 μL / g or more. The upper limit is preferably 20 μL / g. If the specific surface area is less than 3 m 2 / g or the volume of pores less than 0.1 μm is less than 10 μL / g, the rapid charge / discharge characteristics may deteriorate.
また、本発明の黒鉛材料の平均粒子径は10〜15μmが好ましい。 The average particle size of the graphite material of the present invention is preferably 10 to 15 μm.
(リチウムイオン二次電池)
本発明の黒鉛材料は、リチウムイオン二次電池の負極材料として用いることができる。負極材料以外の電池の構成要素、すなわち、正極材料、電解質、セパレータ、バインダー、集電体などについては特に限定されることはなく、リチウムイオン二次電池に関する公知の技術を適用することができる。(Lithium-ion secondary battery)
The graphite material of the present invention can be used as a negative electrode material for a lithium ion secondary battery. The components of the battery other than the negative electrode material, that is, the positive electrode material, the electrolyte, the separator, the binder, the current collector, and the like are not particularly limited, and known techniques relating to the lithium ion secondary battery can be applied.
以下に、本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.
次に本発明を実施例により具体的に説明するが、本発明はこれら実施例に限定されるものではない。また以下の実施例および比較例では、図1に示すように、少なくとも表面の一部に本発明の負極材料を有する負極合剤2が付着した集電体(負極)7bとリチウム箔よりなる対極(正極)4から構成される単極評価用のボタン型二次電池を作製して評価した。実電池は、本発明の概念に基づき、公知の方法に準じて作製することができる。
なお以下の実施例及び比較例において、材料の物性は以下の方法により測定した。
平均粒径は、レーザー回折式粒度分布径により測定した粒度分布の累積度数が体積百分率で50%となる粒子径である。
比表面積は、窒素ガス吸着によるBET法により求めた。
X線広角回折における(002)面の平均格子面間隔d002は、前述の学振法により求めた。
0.1μm以下の細孔容積は、水銀圧入法により求めた。Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Further, in the following Examples and Comparative Examples, as shown in FIG. 1, a counter electrode composed of a current collector (negative electrode) 7b to which the
In the following Examples and Comparative Examples, the physical characteristics of the materials were measured by the following methods.
The average particle size is a particle size at which the cumulative frequency of the particle size distribution measured by the laser diffraction type particle size distribution diameter is 50% by volume.
The specific surface area was determined by the BET method by adsorbing nitrogen gas.
The average lattice plane spacing d 002 of the (002) plane in X-ray wide-angle diffraction was determined by the above-mentioned Gakushin method.
The pore volume of 0.1 μm or less was determined by the mercury intrusion method.
(実施例1)
[黒鉛材料の作製]
コールタールピッチを窒素雰囲気中450℃で熱処理し、メソフェーズ小球体(平均粒径40μm)を生成させた。次いでタール中油を用いてコールタールピッチからピッチマトリックスを抽出し、さらにタール中油からメソフェーズ小球体を分離し、乾燥した。該小球体を窒素雰囲気下500℃で3時間熱処理して、メソフェーズ小球体焼成物(平均粒径34μm)を得た。
次に該焼成物をハンマーミルで粉砕し、平均粒径15μmとした。該粉砕物100質量部、二酸化珪素4.3質量部(珪素元素2質量部)、酸化第二鉄2.9質量部(鉄元素2質量部)をスクリューミキサーに投入し、30分間混合した。該混合物を黒鉛坩堝に充填し、アチソン炉にて3150℃で5時間熱処理して黒鉛化を行った。該黒鉛化物の灰分(燃焼法)は0.01%未満であった。
次いで、前記黒鉛化物をメカノフュージョンシステム(ホソカワミクロン(株))に投入し、ローター周速20m/sで30分間運転し、解砕を行った。最後に解砕物を53μmの篩に通し、目的の黒鉛材料を得た。(Example 1)
[Preparation of graphite material]
The coal tar pitch was heat-treated at 450 ° C. in a nitrogen atmosphere to produce mesophase globules (average particle size 40 μm). Then, the pitch matrix was extracted from the coal tar pitch using the tar oil, and the mesophase globules were further separated from the tar oil and dried. The microspheres were heat-treated at 500 ° C. for 3 hours in a nitrogen atmosphere to obtain a calcined mesophase microspheres (average particle size 34 μm).
Next, the fired product was crushed with a hammer mill to have an average particle size of 15 μm. 100 parts by mass of the pulverized product, 4.3 parts by mass of silicon dioxide (2 parts by mass of silicon element), and 2.9 parts by mass of ferric oxide (2 parts by mass of iron element) were put into a screw mixer and mixed for 30 minutes. The mixture was filled in a graphite crucible and heat-treated in an Achison furnace at 3150 ° C. for 5 hours for graphitization. The ash content (combustion method) of the graphitized product was less than 0.01%.
Next, the graphitized product was put into a mechanofusion system (Hosokawa Micron Co., Ltd.) and operated at a rotor peripheral speed of 20 m / s for 30 minutes to perform crushing. Finally, the pyroclastic material was passed through a 53 μm sieve to obtain the desired graphite material.
[負極合剤ペーストの作製]
次に、該黒鉛材料を負極材料として用いて負極を作製した。まず、負極材料を96質量部、結合剤としてのカルボキシメチルセルロース2質量部、およびスチレン−ブタジエンゴム2質量部を水に入れ、攪拌して負極合剤ペーストを調整した。次いで、この銅箔上に塗布された負極合剤層を150MPaの圧力でプレスした。さらに、銅箔と負極合剤層を直径15.5mmの円柱状に打抜いて、銅箔に密着した負極合剤層を有する作用電極(負極)を作製した。[Preparation of negative electrode mixture paste]
Next, a negative electrode was produced using the graphite material as a negative electrode material. First, 96 parts by mass of the negative electrode material, 2 parts by mass of carboxymethyl cellulose as a binder, and 2 parts by mass of styrene-butadiene rubber were put into water and stirred to prepare a negative electrode mixture paste. Next, the negative electrode mixture layer coated on the copper foil was pressed at a pressure of 150 MPa. Further, the copper foil and the negative electrode mixture layer were punched into a columnar shape having a diameter of 15.5 mm to prepare a working electrode (negative electrode) having a negative electrode mixture layer in close contact with the copper foil.
[対極(正極)の作製]
次に、前記負極を用いて単極評価用のボタン型二次電池を作製した。正極にはニッケルネットからなる集電体と、該集電体に密着したリチウム金属箔からなる極板を用いた。[Preparation of counter electrode (positive electrode)]
Next, a button-type secondary battery for unipolar evaluation was produced using the negative electrode. For the positive electrode, a current collector made of a nickel net and a electrode plate made of a lithium metal foil in close contact with the current collector were used.
[電解液・セパレータ]
電解液は、エチレンカーボネート33体積%とメチルエチルカーボネート67体積%の混合溶剤に、LiPF6を1mol/Lとなる濃度で溶解させ、非水電解液を調製した。得られた非水電解液を厚さ20μmのポリプロピレン多孔質体に含侵させ、電解液が含侵されたセパレータを作成した。[Electrolytic solution / separator]
The electrolytic solution was prepared by dissolving LiPF 6 in a mixed solvent of 33% by volume of ethylene carbonate and 67% by volume of methyl ethyl carbonate at a concentration of 1 mol / L to prepare a non-aqueous electrolytic solution. The obtained non-aqueous electrolytic solution was impregnated into a polypropylene porous body having a thickness of 20 μm to prepare a separator impregnated with the electrolytic solution.
[評価電池の構成]
図1に評価電池の構成としてボタン型二次電池を示す。
外装カップ1と外装缶3は、その周縁部において絶縁ガスケット6を介在させ、両周縁部をかしめて密閉した。その内部に外装缶3の内面から順に、ニッケルネットからなる集電体7a、リチウム箔よりなる円筒状の対極(正極)4、電解液が含浸されたセパレータ5、負極合剤2が付着した銅箔からなる集電体7bが積層された電池系である。
前記評価電池は電解液を含浸させたセパレータ5を集電体7bと負極合剤2からなる作用電極(負極)と、集電体7aに密着した対極4との間に挟んで積層した後、集電体7bを外装カップ1内に、対極4を外装缶3内に収容して、外装カップ1と外装缶3とを合わせ、さらに、外装カップ1と外装缶3との周縁部に絶縁ガスケット6を介在させ、両周縁部をかしめて密閉して作製した。
以上により作製された評価電池について、25℃の温度下で以下に示す充放電試験を行い、初期充放電効率,急速充電率,急速放電率を計算した。
また、電極密度は、厚みと負極合剤の質量から計算した。[Evaluation battery configuration]
FIG. 1 shows a button-type secondary battery as a configuration of the evaluation battery.
The
In the evaluation battery, a
The evaluation batteries manufactured as described above were subjected to the following charge / discharge tests at a temperature of 25 ° C., and the initial charge / discharge efficiency, the fast charge rate, and the fast discharge rate were calculated.
The electrode density was calculated from the thickness and the mass of the negative electrode mixture.
[初期充放電効率]
回路電圧が0mVに達するまで0.9mAの定電流充電を行った後、回路電圧が0mVに達した時点で定電圧充電に切替え、さらに電流値が20μAになるまで充電を続けた。その間の通電量から質量当たりの充電容量(単位:mAh/g)を求めた。その後、120分間休止した。次に0.9mAの電流値で回路電圧が1.5Vに達するまで定電流放電を行い、この間の通電量から質量当たりの放電容量(単位:mAh/g)を求めた。式(1)により初期充放電効率を計算した。
初期充放電効率(%)=(放電容量/充電容量)×100 ・・・(1)
なおこの試験では、リチウムイオンを負極材料に吸蔵する過程を充電、負極材料から離脱する過程を放電とした。[Initial charge / discharge efficiency]
After constant current charging of 0.9 mA until the circuit voltage reached 0 mV, switching to constant voltage charging was performed when the circuit voltage reached 0 mV, and charging was continued until the current value reached 20 μA. The charge capacity per mass (unit: mAh / g) was determined from the amount of electricity energized during that period. Then, it rested for 120 minutes. Next, constant current discharge was performed with a current value of 0.9 mA until the circuit voltage reached 1.5 V, and the discharge capacity per mass (unit: mAh / g) was determined from the amount of energization during this period. The initial charge / discharge efficiency was calculated by the formula (1).
Initial charge / discharge efficiency (%) = (discharge capacity / charge capacity) x 100 ... (1)
In this test, the process of occluding lithium ions in the negative electrode material was defined as charging, and the process of releasing lithium ions from the negative electrode material was defined as discharging.
[急速充電率]
引き続き第2サイクルにて急速充電を行った。
電流値を6mAとして、回路電圧が0mVに達するまで定電流充電を行い、充電容量を求め、式(2)により急速充電率を計算した。
急速充電率(%)=(急速定電流充電容量/初期放電容量)×100 ・・・(2)[Fast charge rate]
Subsequently, quick charging was performed in the second cycle.
With the current value set to 6 mA, constant current charging was performed until the circuit voltage reached 0 mV, the charging capacity was obtained, and the quick charging rate was calculated by the formula (2).
Rapid charge rate (%) = (Rapid constant current charge capacity / initial discharge capacity) x 100 ... (2)
[急速放電率]
同じ第2サイクルにて急速放電を行った。
第1サイクルと同様に定電圧充電に切り替えて満充電した後、電流値を12mAとして、回路電圧が1.5Vに達するまで定電流放電を行った。得られた放電容量から、式(3)により急速放電率を計算した。
急速放電率(%)=(急速放電容量/初期放電容量)×100 ・・・(3)[Fast discharge rate]
Fast discharge was performed in the same second cycle.
After switching to constant voltage charging and fully charging in the same manner as in the first cycle, constant current discharge was performed until the circuit voltage reached 1.5 V, with the current value set to 12 mA. From the obtained discharge capacity, the rapid discharge rate was calculated by the formula (3).
Rapid discharge rate (%) = (fast discharge capacity / initial discharge capacity) x 100 ... (3)
(実施例2)
実施例1において、メソフェーズ小球体焼成物の粉砕粒径を10μmとした。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Example 2)
In Example 1, the pulverized particle size of the mesophase small sphere fired product was set to 10 μm. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(実施例3)
実施例1において、二酸化珪素2.1質量部(珪素元素1質量部)、酸化第二鉄1.4質量部(鉄元素1質量部)を用いてメソフェーズ小球体焼成体粉砕物との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Example 3)
In Example 1, 2.1 parts by mass of silicon dioxide (1 part by mass of silicon element) and 1.4 parts by mass of ferric oxide (1 part by mass of iron element) were mixed with a pulverized mesophase small sphere calcined product. went. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(実施例4)
実施例1において、二酸化珪素2.1質量部(珪素元素1質量部)、酸化第二鉄4.3質量部(鉄元素3質量部)を用いてメソフェーズ小球体焼成体粉砕物との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Example 4)
In Example 1, 2.1 parts by mass of silicon dioxide (1 part by mass of silicon element) and 4.3 parts by mass of ferric oxide (3 parts by mass of iron element) were mixed with a pulverized mesophase small sphere. went. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(実施例5)
実施例1において、二酸化珪素6.4質量部(珪素元素3質量部)、酸化第二鉄1.4質量部(鉄元素1質量部)を用いてメソフェーズ小球体焼成体粉砕物との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Example 5)
In Example 1, 6.4 parts by mass of silicon dioxide (3 parts by mass of silicon element) and 1.4 parts by mass of ferric oxide (1 part by mass of iron element) were mixed with a pulverized mesophase small spherical body. went. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例1)
実施例1において、二酸化珪素8.6質量部(珪素元素4質量部)を用い、酸化第二鉄は用いずにメソフェーズ小球体焼成体粉砕物との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 1)
In Example 1, 8.6 parts by mass of silicon dioxide (4 parts by mass of silicon element) was used, and ferric oxide was not used, and the mixture was mixed with a pulverized mesophase small sphere calcined product. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例2)
実施例1において、酸化第二鉄5.7質量部(鉄元素4質量部)を用い、二酸化珪素は用いずにメソフェーズ小球体焼成体粉砕物との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 2)
In Example 1, 5.7 parts by mass of ferric oxide (4 parts by mass of iron element) was used, and silicon dioxide was not used, and the mixture was mixed with the pulverized mesophase small sphere calcined product. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例3)
実施例1において、二酸化珪素も酸化第二鉄も用いずにメソフェーズ小球体焼成物の粉砕物のみで黒鉛化を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 3)
In Example 1, graphitization was carried out using only the pulverized mesophase microsphere calcined product without using silicon dioxide or ferric oxide. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例4)
実施例1において、メソフェーズ小球体焼成物を粉砕せずに、二酸化珪素および酸化第二鉄との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 4)
In Example 1, silicon dioxide and ferric oxide were mixed without pulverizing the calcined mesophase microspheres. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例5)
実施例1において、加熱条件を変えて平均粒径15μmのメソフェーズ小球体を生成させた。該小球体の分離、乾燥、焼成により平均粒径11μmのメソフェーズ小球体焼成物を得た後、粉砕はせずに、二酸化珪素および酸化第二鉄との混合を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 5)
In Example 1, mesophase globules having an average particle size of 15 μm were generated by changing the heating conditions. A mesophase small sphere calcined product having an average particle size of 11 μm was obtained by separating, drying, and firing the small spheres, and then mixed with silicon dioxide and ferric oxide without pulverization. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
(比較例6)
実施例1において、黒鉛化物を解砕しなかった以外は、実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 6)
In Example 1, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1 except that the graphitized product was not crushed.
(比較例7)
実施例1において、加熱条件を変えてメソフェーズ小球体の発生粒径を15μmとした。該小球体の分離、乾燥、焼成後、粉砕も二酸化珪素および酸化第二鉄の混合も行わずに、実施例1と同様にメカノフュージョンシステムで黒鉛化物の解砕を行った。それ以外は実施例1と同様に黒鉛材料の作製と電池特性の評価を行った。(Comparative Example 7)
In Example 1, the heating conditions were changed so that the generated particle size of the mesophase globules was 15 μm. After the small spheres were separated, dried, and calcined, the graphitized product was crushed by a mechanofusion system in the same manner as in Example 1 without pulverization or mixing of silicon dioxide and ferric oxide. Other than that, the graphite material was prepared and the battery characteristics were evaluated in the same manner as in Example 1.
以上の評価結果を表1に示した。本発明の黒鉛材料は、リチウムイオン二次電池用負極材料として高い電極密度、高い放電容量、優れた急速充放電特性を示す。 The above evaluation results are shown in Table 1. The graphite material of the present invention exhibits high electrode density, high discharge capacity, and excellent rapid charge / discharge characteristics as a negative electrode material for a lithium ion secondary battery.
1 外装カップ
2 作用電極(負極)
3 外装缶
4 対極(正極)
5 セパレータ
6 絶縁ガスケット
7a、7b 集電体1
3 Exterior can 4 Counter electrode (positive electrode)
5
Claims (5)
前記粉砕工程で得られた粉砕物を、珪素元素および鉄元素の存在下で黒鉛化する黒鉛化工程と、
前記黒鉛化工程で得られた黒鉛化物を解砕する解砕工程からなる黒鉛材料の製造方法であって、
前記粉砕物の平均粒子径が10μm以上、15μm以下であり、
前記黒鉛材料の平均粒子径が10μm以上、15μm以下である黒鉛材料の製造方法。 A crushing process for crushing mesophase small sphere fired products,
A graphitization step of graphitizing the pulverized product obtained in the pulverization step in the presence of silicon element and iron element,
A method for producing a graphite material, which comprises a crushing step of crushing the graphitized product obtained in the graphitization step.
The average particle size of the pulverized product is 10 μm or more and 15 μm or less.
A method for producing a graphite material, wherein the average particle size of the graphite material is 10 μm or more and 15 μm or less .
前記鉄元素の添加量が前記粉砕物100質量部に対し1質量部以上、5質量部以下である請求項1に記載の黒鉛材料の製造方法。 The amount of the silicon element added is 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pulverized product.
The method for producing a graphite material according to claim 1 , wherein the amount of the iron element added is 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pulverized product.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2019168029 | 2019-09-17 | ||
JP2019168029 | 2019-09-17 | ||
PCT/JP2020/027915 WO2021053956A1 (en) | 2019-09-17 | 2020-07-17 | Method for manufacturing graphite material |
Publications (2)
Publication Number | Publication Date |
---|---|
JP6905159B1 true JP6905159B1 (en) | 2021-07-21 |
JPWO2021053956A1 JPWO2021053956A1 (en) | 2021-10-07 |
Family
ID=74884175
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2020568829A Active JP6905159B1 (en) | 2019-09-17 | 2020-07-17 | Method for manufacturing graphite material |
Country Status (5)
Country | Link |
---|---|
JP (1) | JP6905159B1 (en) |
KR (1) | KR102527750B1 (en) |
CN (1) | CN112996749A (en) |
TW (1) | TWI739534B (en) |
WO (1) | WO2021053956A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023021957A1 (en) * | 2021-08-17 | 2023-02-23 | Jfeケミカル株式会社 | Carbon-coated graphite particles, negative electrode for lithium-ion secondary battery, and lithium-ion secondary battery |
CN114291814B (en) * | 2021-12-24 | 2024-04-16 | 东北师范大学 | Graphite negative electrode material and preparation method and application thereof |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11185757A (en) * | 1997-12-17 | 1999-07-09 | Toyo Tanso Kk | Negative electrode material for lithium-ion secondary battery, manufacture thereof and lithium-ion secondary battery using the material |
JP2007031233A (en) * | 2005-07-28 | 2007-02-08 | Jfe Chemical Corp | Method for producing graphite material |
JP2007191369A (en) * | 2006-01-20 | 2007-08-02 | Jfe Chemical Corp | Method for producing fine graphite particle |
WO2009157478A1 (en) * | 2008-06-25 | 2009-12-30 | 三菱化学株式会社 | Composite graphite particle for nonaqueous secondary battery, and negative electrode material, negative electrode, and nonaqueous secondary battery containing the same |
JP2012133981A (en) * | 2010-12-21 | 2012-07-12 | Jfe Chemical Corp | Negative electrode material for lithium ion secondary battery, lithium ion secondary battery negative electrode, and lithium ion secondary battery |
JP2013229343A (en) * | 2013-06-28 | 2013-11-07 | Mitsubishi Chemicals Corp | Composite graphite particle for nonaqueous secondary battery, negative electrode material containing the same, negative electrode and nonaqueous secondary battery |
JP2014067643A (en) * | 2012-09-26 | 2014-04-17 | Mitsubishi Chemicals Corp | Carbon material for nonaqueous secondary battery, negative electrode, and nonaqueous secondary battery |
JP2016085906A (en) * | 2014-10-28 | 2016-05-19 | Jfeケミカル株式会社 | Graphite particle for lithium ion secondary battery negative electrode material, lithium ion secondary battery negative electrode and lithium ion secondary battery |
WO2016113952A1 (en) * | 2015-01-16 | 2016-07-21 | 三菱化学株式会社 | Carbon material and nonaqueous secondary battery using carbon material |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2884746B2 (en) | 1990-09-03 | 1999-04-19 | 松下電器産業株式会社 | Non-aqueous electrolyte secondary battery |
JP4945029B2 (en) * | 2001-03-06 | 2012-06-06 | 新日鐵化学株式会社 | Material for negative electrode of lithium secondary battery, method for producing the same, and lithium secondary battery |
JP4666876B2 (en) * | 2001-09-26 | 2011-04-06 | Jfeケミカル株式会社 | Composite graphite material and method for producing the same, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery |
KR100575971B1 (en) * | 2002-03-27 | 2006-05-02 | 제이에프이 케미칼 가부시키가이샤 | Mesophase spherular graphitized substance, anode material, anode, and lithium ion secondary battery using same |
JP4672958B2 (en) * | 2002-10-10 | 2011-04-20 | Jfeケミカル株式会社 | Graphite particles, lithium ion secondary battery, negative electrode material therefor and negative electrode |
KR100908371B1 (en) * | 2004-08-27 | 2009-07-20 | 제이에프이 케미칼 가부시키가이샤 | Graphite material and its manufacturing method, negative electrode material for lithium ion secondary battery, negative electrode for lithium ion secondary battery and lithium ion secondary battery |
-
2020
- 2020-07-17 JP JP2020568829A patent/JP6905159B1/en active Active
- 2020-07-17 WO PCT/JP2020/027915 patent/WO2021053956A1/en active Application Filing
- 2020-07-17 CN CN202080004108.1A patent/CN112996749A/en active Pending
- 2020-07-17 KR KR1020217001100A patent/KR102527750B1/en active IP Right Grant
- 2020-07-31 TW TW109125912A patent/TWI739534B/en active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11185757A (en) * | 1997-12-17 | 1999-07-09 | Toyo Tanso Kk | Negative electrode material for lithium-ion secondary battery, manufacture thereof and lithium-ion secondary battery using the material |
JP2007031233A (en) * | 2005-07-28 | 2007-02-08 | Jfe Chemical Corp | Method for producing graphite material |
JP2007191369A (en) * | 2006-01-20 | 2007-08-02 | Jfe Chemical Corp | Method for producing fine graphite particle |
WO2009157478A1 (en) * | 2008-06-25 | 2009-12-30 | 三菱化学株式会社 | Composite graphite particle for nonaqueous secondary battery, and negative electrode material, negative electrode, and nonaqueous secondary battery containing the same |
JP2012133981A (en) * | 2010-12-21 | 2012-07-12 | Jfe Chemical Corp | Negative electrode material for lithium ion secondary battery, lithium ion secondary battery negative electrode, and lithium ion secondary battery |
JP2014067643A (en) * | 2012-09-26 | 2014-04-17 | Mitsubishi Chemicals Corp | Carbon material for nonaqueous secondary battery, negative electrode, and nonaqueous secondary battery |
JP2013229343A (en) * | 2013-06-28 | 2013-11-07 | Mitsubishi Chemicals Corp | Composite graphite particle for nonaqueous secondary battery, negative electrode material containing the same, negative electrode and nonaqueous secondary battery |
JP2016085906A (en) * | 2014-10-28 | 2016-05-19 | Jfeケミカル株式会社 | Graphite particle for lithium ion secondary battery negative electrode material, lithium ion secondary battery negative electrode and lithium ion secondary battery |
WO2016113952A1 (en) * | 2015-01-16 | 2016-07-21 | 三菱化学株式会社 | Carbon material and nonaqueous secondary battery using carbon material |
Also Published As
Publication number | Publication date |
---|---|
TW202112662A (en) | 2021-04-01 |
JPWO2021053956A1 (en) | 2021-10-07 |
KR20210035170A (en) | 2021-03-31 |
TWI739534B (en) | 2021-09-11 |
WO2021053956A1 (en) | 2021-03-25 |
CN112996749A (en) | 2021-06-18 |
KR102527750B1 (en) | 2023-04-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5348878B2 (en) | Negative electrode material for lithium ion secondary battery and method for producing the same, negative electrode for lithium ion secondary battery, and lithium ion secondary battery | |
KR101661050B1 (en) | Composite graphite material, method for producing same, negative electrode material for lithium ion secondary batteries, negative electrode for lithium ion secondary batteries, and lithium ion secondary battery | |
KR20130094853A (en) | Anode material for lithium ion rechargeable battery, anode for lithium ion rechargeable battery, and lithium ion rechargeable battery | |
KR20110033134A (en) | Composite graphite particle for nonaqueous secondary battery, and negative electrode material, negative electrode, and nonaqueous secondary battery containing the same | |
JP2001023637A (en) | Graphite powder for lithium ion secondary battery negative electrode and manufacture of the graphite powder | |
JP6905159B1 (en) | Method for manufacturing graphite material | |
JP2018006270A (en) | Graphite carbon material for lithium ion secondary battery negative electrode, method for manufacturing the same, and negative electrode or battery arranged by use thereof | |
JP6584975B2 (en) | Carbon material for negative electrode of lithium ion secondary battery, negative electrode of lithium ion secondary battery, and method for producing lithium ion secondary battery | |
JP6957127B1 (en) | Carbon material for negative electrode of lithium ion secondary battery and its manufacturing method, and negative electrode and lithium ion secondary battery using it | |
JP5394721B2 (en) | Lithium ion secondary battery, negative electrode material and negative electrode therefor | |
JP2016178008A (en) | Negative electrode active material for lithium ion secondary battery, and method for manufacturing the same | |
JP2000003708A (en) | Coated carbon material, manufacture thereof and lithium secondary battery using the material | |
JP5551883B2 (en) | Method for producing mesophase microspheres and carbon material, and lithium ion secondary battery | |
JP2004134244A (en) | Graphite particle, lithium ion secondary battery, negative electrode material for it, and negative electrode | |
JP2003263982A (en) | Manufacturing method of graphite particle and negative electrode material for lithium ion secondary battery | |
JP6401117B2 (en) | Method for producing negative electrode material for lithium ion secondary battery | |
JP4707570B2 (en) | Method for producing fine graphite particles | |
JP5133543B2 (en) | Method for producing mesocarbon microsphere graphitized material | |
JP7210810B1 (en) | Method for producing carbonaceous coated graphite material | |
KR102687169B1 (en) | Method for producing carbonaceous coated graphite material | |
JP6924917B1 (en) | Carbon material for negative electrode of lithium ion secondary battery and its manufacturing method, and negative electrode and lithium ion secondary battery using it | |
JP6911221B1 (en) | Carbonaceous material, manufacturing method of carbonaceous material, negative electrode for lithium ion secondary battery and lithium ion secondary battery | |
WO2024116814A1 (en) | Negative electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery | |
KR102632742B1 (en) | Carbonaceous material, method for producing carbonaceous material, negative electrode for lithium ion secondary battery, and lithium ion secondary battery | |
WO2024116847A1 (en) | Negative electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20201210 |
|
A871 | Explanation of circumstances concerning accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A871 Effective date: 20201210 |
|
A975 | Report on accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A971005 Effective date: 20210302 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20210316 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20210426 |
|
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: 20210615 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20210624 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 6905159 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |