WO2014002477A1 - リチウムイオン二次電池負極用の黒鉛材料、それを用いたリチウムイオン二次電池及びリチウムイオン二次電池用の黒鉛材料の製造方法 - Google Patents
リチウムイオン二次電池負極用の黒鉛材料、それを用いたリチウムイオン二次電池及びリチウムイオン二次電池用の黒鉛材料の製造方法 Download PDFInfo
- Publication number
- WO2014002477A1 WO2014002477A1 PCT/JP2013/003957 JP2013003957W WO2014002477A1 WO 2014002477 A1 WO2014002477 A1 WO 2014002477A1 JP 2013003957 W JP2013003957 W JP 2013003957W WO 2014002477 A1 WO2014002477 A1 WO 2014002477A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- graphite material
- negative electrode
- lithium ion
- ion secondary
- secondary battery
- Prior art date
Links
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
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/04—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of carbon-silicon compounds, carbon or silicon
-
- 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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- 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
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/74—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by peak-intensities or a ratio thereof only
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/77—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by unit-cell parameters, atom positions or structure diagrams
-
- 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
- C01P2006/40—Electric properties
-
- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Definitions
- the technology disclosed in the present specification relates to a graphite material used for a negative electrode of a lithium ion secondary battery and a manufacturing method thereof.
- Lithium ion secondary batteries are lighter and have higher input / output characteristics than conventional secondary batteries such as nickel cadmium batteries, nickel metal hydride batteries, and lead batteries, so that portable electronic devices such as mobile phones, It has been put to practical use as a power source for driving notebook PCs.
- a carbon material capable of inserting and extracting lithium ions is generally used.
- graphite materials are dominant from the viewpoint of realizing a flat discharge potential and a high capacity density.
- Non-Patent Document 1 It has been reported that the higher the capacity of the graphite material, the easier it is to stably form an intercalation compound with lithium as the crystalline graphite structure develops, and because a large amount of lithium is inserted between the layers of the carbon network, a high discharge capacity can be obtained.
- the surface of a highly crystalline graphite material is coated with low crystalline carbon using a pyrolysis gas of an organic compound such as propane or benzene (see Patent Document 1), and the graphite precursor is mechanochemical.
- a method of making a substantially multi-layer structure has been proposed, such as graphitizing to make the surface crystallinity relatively lower than the crystallinity of the nucleus (see Patent Document 2). It is piled up.
- Japanese Patent Laid-Open No. 10-12241 Japanese Patent No. 4171259 Japanese Patent No. 4877568 Japanese Patent No. 4896381 Japanese Patent No. 4738553 JP 2011-82054 A
- lithium secondary batteries have begun to be used not only for small power supplies but also for large-capacity large batteries used for power storage and electric vehicles.
- the required performance for lithium secondary batteries for power storage or electric vehicles requires much higher reliability than that for small power supply applications.
- "reliability” is a characteristic relating to the life, and even when the charge / discharge cycle is repeated, or when it is stored in a state where it is charged to a predetermined voltage, it is continuously charged at a constant voltage. In the case (when floating charging is performed), the charge / discharge capacity and the internal resistance are not easily changed (not easily deteriorated).
- the multi-layered, highly crystalline graphite materials mentioned above have excellent initial efficiency, but it is difficult to satisfy the reliability that guarantees the reliability of the yearly unit. There are also challenges.
- Patent Document 3 Focusing only on the input / output characteristics, the use of an amorphous carbon material is also considered (Patent Document 3), but it has the disadvantage that a high capacity density cannot be obtained and the irreversible capacity is large.
- An object of the present invention is to provide a graphite material for a negative electrode capable of improving input / output characteristics and cycle characteristics of a lithium ion secondary battery.
- the inventors of the present invention reduce the parallelism of the carbon network surface by introducing lattice strain into the graphite crystallites, and control the ratio of amorphous carbon to crystalline carbon.
- By providing a manufacturing method that does not require high efficiency it provides a graphite material with high activity and low dangling bonds, which not only improves the charge / discharge efficiency of the negative electrode but also inherently contradictory characteristics, initial efficiency, input / output
- the inventors of the present invention have come up with the present invention as a result of diligent research on the idea that a lithium ion secondary battery having a good balance between characteristics and cycle characteristics can be obtained.
- Lc (112) / Lc (006) defined as a ratio between the spread of the carbon network surface and the misalignment of the stack is in the range of 0.08 to 0.11.
- the crystallite size Lc (006) calculated from the X-ray wide-angle diffraction line is 30 nm to 40 nm, and the average particle size is 3 ⁇ m to 20 ⁇ m.
- the above graphite material is preferably used for, for example, a negative electrode of a lithium ion secondary battery or a lithium ion capacitor.
- the method for producing a graphite material for a negative electrode of a lithium ion secondary battery according to an embodiment of the present invention has an optically isotropic texture ratio of 75% or more, a total transition metal content of 1000 or more and 2500 ppm, and a nitrogen content of By pulverizing and classifying petroleum non-acicular coke that is 1 wt% or more and 4 wt% or less, a process of processing the average particle diameter of the petroleum non-acicular coke to a range of 3 ⁇ m or more and 20 ⁇ m or less, and the processed And graphitizing petroleum non-acicular coke at a temperature of 2300 ° C. or higher and 2900 ° C. or lower.
- the graphite material according to an embodiment of the present invention for example, it is possible to reduce the capacity deterioration of a lithium secondary battery, and to provide a negative electrode of a lithium secondary battery having high initial efficiency, input / output characteristics, and reliability. Can do.
- FIG. 1 is a cross-sectional view showing a lithium ion secondary battery according to an embodiment of the present invention.
- FIG. 2 is a diagram showing measurement results of physical properties of graphite materials according to each example and comparative example.
- the lattice strain here refers to a state in which the parallelism of the carbon network surface is low. This lattice strain is caused by the introduction of vanadium or nickel into defects in the interlayer or carbon plane, where the nitrogen of impurities incorporated into the material escapes and the carbon network surface is distorted during carbonization or graphitization. This is caused by the fact that the spacing between the carbon network surfaces is widened by each other, or is inhibited by growth between adjacent crystallites.
- Lc (112) / Lc (006) defined as a ratio between the spread of the carbon network surface and the misalignment of the stack is in the range of 0.08 to 0.11.
- Lc is the crystallite size in the c-axis direction calculated from the X-ray wide-angle diffraction line
- Lc (112) / Lc (006) is a distortion parameter.
- crystallites having strains in the a-axis and c-axis directions are directed in random directions
- Lc (112) / Lc (006) is 0.08 or more and 0.11 or less.
- Lc (112) / Lc (006) is preferably 0.085 or more and 0.108 or less.
- the graphite material of this embodiment has Lc (006) of 30 nm or more and 40 nm or less.
- Lc (006) is 40 nm or less, the cycle retention rate can be improved when the graphite material is used for the negative electrode, and when Lc (006) is 30 nm or more, the battery capacity is sufficiently high. can do.
- the graphite material of this embodiment has an average particle diameter (D50) of 3 ⁇ m or more and 20 ⁇ m or less, as will be described later.
- D50 average particle diameter
- the average particle diameter (D50) of the graphite material is more preferably 5 ⁇ m or more and 15 ⁇ m or less.
- Lc (006) / C0 (006) defined as a value indicating the amount of lithium storage sites in the crystallite is 40 or more and 60 or less.
- this graphite material contains a transition metal as an impurity, and the total transition metal content in the graphite material is preferably 100 ppm or more and 2500 ppm or less.
- the total transition metal content in the graphite material is 100 ppm or more
- the graphite material is used for the negative electrode, the expansion and contraction of the graphite material accompanying the insertion / extraction of lithium is alleviated to an appropriate range.
- main transition metal elements contained in the graphite material include vanadium, nickel, iron, copper, and manganese. In particular, the vanadium content in the graphite material is about 50 ppm or more.
- FIG. 1 is a view showing an example of a lithium ion secondary battery including a negative electrode using the graphite material of the present embodiment.
- a lithium ion secondary battery 10 includes a negative electrode 11, a negative electrode current collector 12, a positive electrode 13, a positive electrode current collector 14, and a negative electrode 11 and a positive electrode 13. And an exterior 16 made of an aluminum laminate film or the like.
- the negative electrode 11 for example, one in which the above-described graphite material of the present embodiment is applied to both surfaces or one surface of a metal foil is used.
- the average particle diameter of the applied graphite material does not substantially change before and after the battery manufacturing process, and is 3 ⁇ m or more and 20 ⁇ m or less.
- the inventors of the present application include a predetermined amount of impurities, an optical isotropic texture ratio of at least 75% or more, a total transition metal content of 1000 ppm to 2500 ppm, and a nitrogen content of 1 to 4 wt%.
- heat treatment is performed under conditions where the temperature can be controlled, thereby generating a predetermined range of lattice strain after graphitization.
- the inventors of the present application consider the relationship between the optically isotropic texture ratio and impurity content of the raw material and the occurrence of lattice strain after graphitization as follows.
- the coke used as the precursor of the graphite material according to the present embodiment is petroleum non-needle-like coke, and in the cross section observed with a polarizing microscope, the optical isotropic structure is uniformly dispersed and is present at 75% or more. To do. In addition, it is more preferable if the optically isotropic organization rate of raw material coke is 85% or more. Coke having an optically isotropic texture ratio of less than 75% is not suitable because crystallites develop too much. A method for calculating the optically isotropic texture will be described in detail later.
- optical isotropic structures means that the optical anisotropy domain in which the carbon network surface is laminated in coke is small, and the orientation of the carbon network surface is not oriented in one direction around it, making it difficult to graphite. This indicates that the properties of carbonized carbon are strong.
- the size of the domain imposes a spatial restriction on the crystallite growth direction during graphitization. Spatial restriction means that the growth of crystallites is hindered by the energy to maintain the domain shape, and the lower the optical anisotropic texture ratio, that is, the smaller the domains, the farther the crystal There are significant spatial limitations on growth.
- the carbon network surface is oriented in a random direction, the directions in which the crystallites expand and contract during charge / discharge of the graphitized material are dispersed, and as a result, the amount of deformation of the electrode is reduced. Thereby, even if charging / discharging is repeated, it becomes easy to hold
- the optically isotropic structure is oriented as the graphitization proceeds, and the crystallinity of the entire graphite material is increased, but the crystallite size is also increased at the same time, and the input / output characteristics are degraded.
- the crystallinity of each crystallite can be increased while keeping the crystallite size small, so that high capacity is maintained. High input / output characteristics can be obtained as is.
- petroleum-based non-acicular coke may contain, as a crude oil-derived impurity, a metal porphyrin obtained by coordinating a transition metal ion mainly composed of vanadium and nickel at the center of the porphyrin ring, or petroleum porphyrin.
- This porphyrin consists of a pyrrole five-membered ring containing nitrogen and has high thermal stability. When this metal porphyrin is heated in coke, it is volatilized and removed by thermal decomposition at a high temperature exceeding 2900 ° C. However, at a relatively low temperature (for example, 2300 ° C. or higher and 2900 ° C.
- nitrogen which is a low molecular component, is largely volatilized, but vanadium, etc. Some of the transition metals only diffuse and do not reach volatile separation from the coke.
- Nitrogen is thought to cause distortion in the carbon network surface at the stage of volatilization and inhibit growth in the carbon plane direction. Therefore, even if almost no nitrogen remains in the graphite after the heat treatment, the carbon network surface of the graphite can be distorted because the raw material coke contains nitrogen. Transition metals such as vanadium and nickel enter the carbon layer (or defects in the carbon plane) and do not participate in the reaction in which lithium is inserted into or removed from the graphite layer. And it is presumed to act as a pillar that prevents shrinkage and prevents collapse of the structure. By such an action, a graphite material having a distribution in the a-axis and c-axis directions is produced.
- a raw material with a high content of different elements is selected in advance, strain on the carbon network surface due to desorption of nitrogen or the like, and further, insertion of an interlayer (in-plane) between transition metals, It is preferable to use a production method in which graphitization proceeds in a situation where growth of crystallites is inhibited.
- the crystal structure of the manufactured graphite material strongly depends on the crystal structure (physical properties) of coke as a raw material.
- the manufacturing method according to the present embodiment that is, after pulverizing and classifying coke containing a predetermined amount of impurities and having a predetermined optical isotropic texture ratio, the temperature can be controlled, and the graphite remains under the condition that a predetermined amount of transition metal remains.
- crystallites having strains in the a-axis and c-axis directions are oriented in random directions.
- the crystallite size Lc in the c-axis direction obtained from each diffraction surface of the X-ray diffraction line has a different value.
- Lc (006) is, for example, 30 nm or more and 40 nm or less, while Lc (112) is 2.4 nm or more and 4.4 nm or less.
- Lc (112) / Lc (006) are defined as strain parameters, the graphite material of the present embodiment has a value in the range of 0.08 to 0.11.
- Lc (112) is preferably 2.5 nm or more and 4.0 nm or less.
- the graphite material of this embodiment has few lithium occlusion sites contained in one crystallite. Therefore, when the value obtained by dividing Lc (006) by the lattice constant C0 (006) (that is, Lc (006) / C0 (006)) is used as an index, the range indicated by the graphite material of the present embodiment is 40 or more and 60 or less. It is preferable. On the other hand, when acicular coke is used as a raw material and processed at a predetermined graphitization temperature, Lc (006) / C0 (006) often does not become a value less than 90.
- the graphite material of the present embodiment having such characteristics is used as a negative electrode, not only the decomposition of the electrolyte solution due to solvent co-insertion is suppressed, but also the edge surface of the particle surface is secured, The rate of lithium movement into the electrolyte is also maintained, and expansion / contraction associated with lithium insertion / extraction is alleviated. Therefore, according to the lithium ion secondary battery using the graphite material of the present embodiment, capacity deterioration can be suppressed, and initial efficiency, input / output characteristics, and reliability can be simultaneously realized at a high level. .
- the graphite material of the present embodiment is used not only as a lithium ion secondary battery but also as a negative electrode material of a lithium ion capacitor. Even in this case, a highly reliable capacitor with high output density can be realized.
- Petroleum-based non-needle coke is used as a carbonaceous material as a raw material.
- the optically isotropic structure is uniformly dispersed and is present at 75% or more, more preferably 85% or more, and the total transition metal content is 1000 ppm or more and 2500 ppm or less, and contains nitrogen.
- the amount is 1 wt% or more and 4 wt% or less.
- Coke having an optically isotropic structure of less than 75% is not suitable as a raw material because crystallites develop too much.
- This petroleum-based non-needle coke is pulverized by a mechanical pulverizer such as a super rotor mill (Nisshin Engineering) or a jet mill (Nihon Pneumatic Industry).
- a mechanical pulverizer such as a super rotor mill (Nisshin Engineering) or a jet mill (Nihon Pneumatic Industry).
- the shape after pulverization has a smaller aspect ratio than the pulverized acicular coke.
- the pulverized product is classified with a precision air classifier, for example, turbo classifier (manufactured by Nisshin Engineering), elbow jet (manufactured by Nittetsu Mining), crusher (manufactured by Seishin Enterprise), etc.
- a precision air classifier for example, turbo classifier (manufactured by Nisshin Engineering), elbow jet (manufactured by Nittetsu Mining), crusher (manufactured by Seishin Enterprise), etc.
- the range of a preferable average particle diameter (D50) is 3 ⁇ m or more and 20 ⁇ m or less.
- the average particle size is based on measurement by a laser diffraction particle size distribution meter. If D50 is less than 3 ⁇ m, the amount of binder necessary to make the graphite material an electrode increases, and the resistance of the electrode increases, which is not preferable.
- an increase in the average particle diameter is not preferable because the lithium free diffusion process in the graphite particles increases and rapid charge / discharge becomes difficult.
- particles with a particle size exceeding 45 ⁇ m are mixed, irregularities on the electrode surface increase and cause damage to the separator used in the battery, so particles with a particle size of substantially 45 ⁇ m or more are included. It is desirable not to be.
- an Atchison furnace, a direct current heating furnace, or the like is known as a known apparatus.
- these furnaces are filled with products called “breeze” and energized between products, so that temperature control is difficult and temperature distribution is large depending on the location. Since it is important to control the thermal history for producing the graphite material of this embodiment, it is preferable to use a batch furnace or a continuous furnace capable of controlling the temperature.
- the heat treatment is performed in a non-oxidizing atmosphere at 2300 ° C. to 2900 ° C., preferably 2400 ° C. to 2800 ° C. In the heat treatment at a temperature of 2250 ° C.
- the temperature increase rate for the heat treatment does not particularly affect the performance within the range of the maximum temperature increase rate and the minimum temperature increase rate in a known apparatus.
- the crystallinity of carbon generally improves with the maximum thermal history, it is said that it is necessary to improve the crystallinity of the carbon material in order to increase the charge / discharge capacity by inserting lithium ions or the like.
- the crystallinity is increased too much, the cycle characteristics and input / output characteristics will deteriorate, so the crystal precursor will be crystallized and the thermal energy applied will be controlled to optimize the amount of lithium storage sites and crystallite size. It is important to make it easier.
- the crystallite size Lc (006) is 30 nm or more and 40 nm or less, the value of Lc (112) / Lc (006) is in the range of 0.08 to 0.11, and vanadium is 50 ppm or more.
- a graphite material containing about 600 ppm or less and about 100 ppm or more and 2500 ppm or less as a content including other transition elements is obtained.
- the average particle size (D50) of the graphite material is substantially the same as the average particle size of the coke before heat treatment, and is 3 ⁇ m or more and 20 ⁇ m or less.
- the graphite material of the present embodiment does not require the step of adding a different element as in the conventional method, and can be produced at a relatively low temperature of 2900 ° C. or less.
- the obtained graphite powder was mixed with 10% by mass of an Si standard sample as an internal standard, the mixed sample was packed in a glass sample holder (25 mm ⁇ ⁇ 0.2 mmt), and a method defined by the Japan Society for the Promotion of Science 117 ( Based on carbon 2006, No. 221, P52-60), measurement was performed by an X-ray wide angle diffraction method, and crystallite sizes Lc (006) and Lc (112) of graphite powder were calculated.
- the X-ray diffractometer was RINT manufactured by Rigaku Corporation, the X-ray source was CuK ⁇ ray (using a K ⁇ filter monochromator), and the applied voltage and current to the X-ray tube were 40 kV and 40 mA, respectively.
- the obtained diffraction pattern was analyzed by a method based on the method (carbon 2006, No. 221, P52-60) defined by the Japan Society for the Promotion of Science 117. Specifically, after performing smoothing processing and background removal on the measurement data, absorption correction, polarization correction, and Lorentz correction were performed. Further, the (006) diffraction line and the (112) diffraction line of the graphite powder are corrected using the peak position and value width of the (422) diffraction line of the Si standard sample, and the crystallite size and lattice constant are corrected. Was calculated.
- the crystallite size was calculated from the half-width of the correction peak using the following Scherrer equation, and the lattice constant was determined by using the following formula obtained by modifying the Bragg equation: d (006) Calculated from C0 (006) can be converted by multiplying d (006) by six. Measurement and analysis were performed 5 times each, and the average value was Lc (006), Lc (112), and C0 (006).
- the results of actual measurement of Lc (006), Lc (112), and C0 (006) of the graphite material are as shown in Table 2.
- the negative electrode for lithium secondary batteries for example, the graphite material which concerns on this embodiment, a binder (binder), a conductive support agent, and an organic solvent as needed.
- the method of pressure-molding the mixture (negative electrode mixture) containing to a predetermined dimension is mentioned.
- the graphite material, the binder (binder), the conductive auxiliary agent and the like according to this embodiment are kneaded and slurried in an organic solvent, and the slurry is applied onto a current collector such as a copper foil.
- a method of rolling a dried product (negative electrode mixture) and cutting it into a predetermined dimension can also be mentioned.
- the graphite material for a lithium ion secondary battery according to the present embodiment can be mixed with a binder (binder) to form a negative electrode mixture and applied to a metal foil to form a negative electrode.
- a binder binder
- binder various conventionally used binders can be used without any particular limitation.
- the binder include polyacrylonitrile (PAN), polyethylene terephthalate, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl fluoride, and SBR (styrene-butadiene rubber).
- PAN polyacrylonitrile
- PVDF polyvinylidene fluoride
- PTFE polytetrafluoroethylene
- SBR styrene-butadiene rubber
- the binder is used in an amount of usually 1 to 40 parts by weight, preferably 2 to 25 parts by weight, particularly preferably 5 to 15 parts by weight with respect to 100 parts by weight of the graphite material for the lithium ion battery of the present embodiment. .
- Examples of the conductive assistant include carbon black, graphite, acetylene black, conductive indium-tin oxide, or conductive polymers such as polyaniline, polythiophene, and polyphenylene vinylene.
- the amount of the conductive aid used is preferably 1 to 15 parts by mass with respect to 100 parts by mass of the carbon material.
- the negative electrode mixture is mixed with a solvent to form a slurry.
- the solvent is not particularly limited as long as it is a conventionally used solvent, and various solvents can be used.
- a solvent for example, N-methylpyrrolidone (NMP), pyrrolidone, N-methylthiopyrrolidone, dimethylformamide (DMF), dimethylacetamide, hexamethylphosphoamide, isopropanol, toluene, etc. may be used alone or in combination. Can do.
- the solvent is generally used in an amount of 15 to 90 parts by mass, preferably 30 to 60 parts by mass with respect to 100 parts by mass in total of the negative electrode mixture.
- the mixture for the negative electrode needs to be appropriately dispersed as long as the graphite material for the lithium ion battery is not destroyed, and is appropriately mixed and dispersed using a planetary mixer, a ball mill, a screw kneader, or the like.
- the slurry mixture of the negative electrode mixture and the solvent is applied to the metal foil.
- the metal foil material there are no particular limitations on the metal foil material, and various metal materials can be used. For example, copper, aluminum, titanium, stainless steel, nickel, iron, etc. are mentioned.
- the mixture can be applied to one side or both sides of the metal foil and dried to form an electrode.
- Application method can be carried out by a conventionally known method.
- the coating method include extrusion coating, gravure coating, curtain coating, reverse roll coating, dip coating, doctor coating, knife coating, screen printing, metal mask printing, electrostatic coating, and the like. After the application, a rolling process using a flat plate press, a calendar roll, or the like is performed as necessary.
- the electrode can be produced by applying the slurry-like mixture to a metal foil and then drying at a temperature of 50 to 250 ° C.
- a temperature of 50 to 250 ° C it is particularly preferable to apply one side, dry at 50 to 250 ° C., and then wash the other side to be applied with water or the like. This cleaning operation can greatly improve the adhesiveness.
- the mixture is applied to one or both sides of the metal foil, and the paste on the dried metal foil is pressed together with the metal foil to form an electrode.
- the shape of the negative electrode may be plate-like, film-like, or cylindrical, depending on the intended battery, and can take various shapes such as being formed on a metal foil.
- a negative electrode formed on a metal foil such as the negative electrode 11 and the negative electrode current collector 12 shown in FIG. 1 can be applied to various batteries as a current collector integrated negative electrode.
- the lithium ion secondary battery When the graphite material of the present embodiment is used as a negative electrode material, the lithium ion secondary battery includes a negative electrode manufactured as described above and a positive electrode for a lithium ion secondary battery, facing each other with a separator interposed therebetween. It can be obtained by injecting the electrolyte into the exterior.
- the active material used for the positive electrode is not particularly limited.
- a metal compound, metal oxide, metal sulfide, or conductive polymer material that can be doped or inserted with lithium ions may be used.
- lithium cobaltate (LiCoO 2), lithium nickelate (LiNiO 2), lithium manganese acid (LiMn 2 O 4), lithium composite oxide (LiCo X Ni Y M Z O 2, X + Y + Z 1, M is Mn, shows the Al or the like) ,
- lithium vanadium compounds, V 2 O 5 , V 6 O 13 , VO 2 , MnO 2 , TiO 2 , MoV 2 O 8 , TiS 2 , V 2 S 5, VS 2, MoS 2, MoS 3, Cr 3 O 8, Cr 2 O 5, olivine-type LiMPO 4 (M is Co, Ni Represents Mn, or Fe), can be mentioned polyacetylene, polyaniline, polypyrrol
- the separator for example, a nonwoven fabric, a cloth, a microporous film, or a combination thereof, which is mainly composed of polyolefin such as polyethylene or polypropylene, can be used.
- a separator when it is set as the structure where the positive electrode and negative electrode of a lithium ion secondary battery to manufacture do not contact directly, it is not necessary to use a separator.
- organic electrolytes As the electrolyte and electrolyte used for the lithium ion secondary battery, known organic electrolytes, inorganic solid electrolytes, and polymer solid electrolytes can be used. Preferably, an organic electrolyte is preferable from the viewpoint of electrical conductivity.
- organic electrolyte examples include dibutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and ethylene glycol phenyl ether; N-methylformamide, N, N-dimethylformamide, N -Amides such as ethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-ethylacetamide, N, N-diethylacetamide; sulfur-containing compounds such as dimethylsulfoxide and sulfolane; methyl ethyl ketone; Dialkyl ketones such as methyl isobutyl ketone; cyclic ethers such as tetrahydrofuran and 2-methoxytetrahydrofuran; ethylene carbonate Cyclic carbonates such as diethyl carbonate, dimethyl carbonate, methyl e
- Lithium salts are used as solutes (electrolytes) for these solvents.
- Commonly known lithium salts include LiClO 4 , LiBF 4 , LiPF 6 , LiAlCl 4 , LiSbF 6 , LiSCN, LiCl, LiCF 3 SO 3 , LiCF 3 CO 2 , LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 and the like, and any of these is used as a solute.
- polymer solid electrolyte examples include a polyethylene oxide derivative and a polymer containing the derivative, a polypropylene oxide derivative and a polymer containing the derivative, a phosphate ester polymer, a polycarbonate derivative and a polymer containing the derivative.
- the optical isotropic texture of coke is investigated as follows. First, an observation sample of about 2 g is placed on the bottom of a plastic sample container having an internal volume of 28 cc. Hardening agent (trade name: curing agent (M agent); manufacturing company: Nippon Oil & Fats Co., Ltd.) to cold embedding resin (trade name: cold embedding resin # 105, manufacturing company: Japan Composite Co., Ltd.) Add 30 seconds with a spatula. The obtained mixture (about 7 mL) is slowly poured into the sample container until the height becomes 1.2 cm, and left to stand for 1 day to solidify.
- Hardening agent trade name: curing agent (M agent); manufacturing company: Nippon Oil & Fats Co., Ltd.
- cold embedding resin trade name: cold embedding resin # 105, manufacturing company: Japan Composite Co., Ltd.
- polishing plate rotating type polishing machine polishing is performed such that the polishing surface is pressed against the rotating surface.
- the rotation of the polishing plate is 1000 rpm.
- the counts of the polishing plates are # 500, # 1000, and # 2000 in order, and finally the mirror polishing is performed using alumina (trade name: Baikalox type 0.3CR, particle size 0.3 ⁇ m, manufacturing company: Baikowski). To do.
- the polished sample was observed using a polarizing microscope (manufactured by Nikon Corporation).
- Table 1 shows the results of evaluating the optically isotropic structure ratio of coke, which is a precursor of the carbon negative electrode material.
- the optically isotropic texture of coke A which is petroleum non-acicular coke, was 88.5%
- the optically isotropic texture of coke B which is acicular coke, was 5%.
- the graphite particle sample was measured for transition metals such as vanadium, nitrogen, lattice spacing, crystallite size, and average particle size.
- transition metals such as vanadium Using SPS-5000 (manufactured by Seiko Denshi Kogyo Co., Ltd.), transition metals including vanadium contained in the sample were quantitatively analyzed by ICP (inductively coupled high frequency plasma emission analysis) method. The total value of each metal content rate is described in Table 3 as impurities.
- Average particle size Measurement was performed using a laser diffraction / scattering particle size distribution analyzer LMS-2000e (manufactured by Seishin Enterprise Co., Ltd.).
- Unipolar battery evaluation A monopolar battery was evaluated using an assembly cell.
- Preparation of electrode sheet paste Add 0.1 part by mass of KF polymer L1320 (N-methylpyrrolidone (NMP) solution containing 12% by mass of polyvinylidene fluoride (PVDF)) to 1 part by mass of graphite particles, and knead with a planetary mixer The base stock solution was used.
- KF polymer L1320 N-methylpyrrolidone (NMP) solution containing 12% by mass of polyvinylidene fluoride (PVDF)
- Electrode sheet preparation NMP was added to the main agent stock solution to adjust the viscosity, and then applied onto a high purity copper foil to a thickness of 75 ⁇ m using a doctor blade. This was pressed to 1 ⁇ 10 3 to 3 ⁇ 10 3 kg / cm against the electrode using a small roll press. Further, this was vacuum-dried at 120 ° C. for 1 hour, and punched out for an assembly type cell 18 mm ⁇ or a laminate cell.
- the assembly type cell was produced as follows. The following operation was performed in a dry argon atmosphere with a dew point of ⁇ 80 ° C. or lower.
- Charging was performed at a constant current charge (CC charge) up to 10 mV at 0.2 C, and the charge was completed when the current decreased to 0.05 C.
- the discharge was a constant current discharge (CC discharge) at 0.2 C and cut off at 2.5 V.
- the initial efficiency is obtained by (discharge capacity / charge capacity) ⁇ 100 [%] at this time.
- Full cell rating The charge / discharge cycle evaluation was performed using a laminate type full cell (positive electrode: commercially available ternary positive electrode material, negative electrode: Examples of the present application or comparative examples).
- electrode sheet paste For the negative electrode, the paste was prepared in the same manner as in the single electrode evaluation.
- the positive electrode paste was prepared as follows.
- Electrode sheet preparation NMP was added to the main agent stock solution to adjust the viscosity, and then applied onto a high purity copper foil to a thickness of 75 ⁇ m using a doctor blade. This was pressed using a small roll press to adjust the electrode density to 2.8 g / cc. Furthermore, this sample was vacuum-dried at 120 ° C. for 1 hour, and then punched out to a predetermined size using a punching die for full-cell electrodes.
- Coke A was pulverized and classified by the above method so that the average particle size (D50) was 5 ⁇ m, and then heat treated at 2400 ° C. to obtain a graphite material. After measuring each physical property of the obtained material, a battery was produced as described above, and initial characteristics at a single electrode and cycle characteristics at a full cell were measured.
- Example 2 Coke A was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2400 ° C. to obtain a graphite material. After measuring each physical property of the obtained material in the same manner as in Example 1, a battery was prepared, and initial characteristics at a single electrode and cycle characteristics at a full cell were measured.
- D50 average particle size
- Coke A was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2600 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Example 4 Coke A was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat-treated at 2800 ° C. to obtain a graphite material. After measuring each physical property in the same manner as in Example 1, a battery was prepared as described above, and initial characteristics at a single electrode and cycle characteristics at a full cell were measured.
- Coke A was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2250 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke A was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 3000 ° C. to obtain a graphite material. After measuring each physical property of the obtained material in the same manner as in Example 1, a battery was prepared, and initial characteristics at a single electrode and cycle characteristics at a full cell were measured.
- Coke A was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat treated at 2250 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke A was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat treated at 2400 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke A was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat treated at 2600 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke A was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat-treated at 2800 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke B was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2250 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke B was pulverized and classified so that the average particle diameter (D50) was 12 ⁇ m, and then heat treated at 2400 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke B was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2600 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke B was pulverized and classified so that the average particle size (D50) was 12 ⁇ m, and then heat treated at 2800 ° C. to obtain a graphite material. After measuring each physical property of the obtained material in the same manner as in Example 1, a battery was prepared, and initial characteristics at a single electrode and cycle characteristics at a full cell were measured.
- Coke B was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat treated at 2400 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Coke B was pulverized and classified so that the average particle size (D50) was 24 ⁇ m, and then heat-treated at 2800 ° C. to obtain a graphite material. Each physical property was measured about the obtained material.
- Table 2 shows the measurement results of the physical properties of the graphite materials according to Examples 1 to 4 and Comparative Examples 1 to 12.
- FIG. 2 is a diagram showing the measurement results shown in Table 2. The broken line shown in FIG. 2 encloses the measurement results of the graphite materials according to Examples 1 to 4.
- the graphite material according to Comparative Example 11 has Lc (112) / Lc (006) of 0.08 or more and 0.11 or less, Lc (006) of 30 nm or more and 40 nm, and Lc (006) / C0 ( 006) was 40 or more and 60 or less.
- Lc (112) / Lc (006) of 0.08 or more and 0.11 or less
- Lc (006) of 30 nm or more and 40 nm
- Lc (006) / C0 ( 006) was 40 or more and 60 or less.
- the average particle size of the graphite material according to Comparative Example 11 exceeds 20 ⁇ m, it is considered that when the graphite material is used, the lithium free diffusion process in the particles becomes large and rapid charge / discharge becomes difficult. .
- Table 3 shows the results of measuring the characteristics of the batteries using the graphite materials according to Examples 1, 2, and 4 and Comparative Examples 2 and 10.
- the capacity retention rates at 60 ° C. and 300 cycles were 80.0%, 80.4%, and 78.1%, respectively, and the capacity was maintained even after repeated charge and discharge. It has been found that the decrease in is very small.
- the total transition metal contents of the graphite materials according to Examples 1, 2, and 4 were 650 ppm, 590 ppm, and 170 ppm, respectively, and the nitrogen content was 300 ppm or less.
- the graphite material according to Comparative Example 10 has an optically isotropic texture ratio of the raw coke of 5%, the amount of impurities after graphitization is below the detection limit, and Lc (112) / Lc (006) is 0. .102. Therefore, although the initial discharge capacity is 350.4 mAh / g and the initial efficiency is very high as 95.0%, the capacity maintenance rate at 60 ° C. and 300 cycles is 14.2%, which is the graphite according to Examples 1, 2, and 4. It was significantly lower than the material. At this time, Lc (006) / C0 (006) was 110.5.
- the graphite material according to the present embodiment is preferably used.
- the capacity of the negative electrode can be maintained at a high level without extremely reducing the capacity even in cycle charge / discharge. Therefore, if the negative electrode graphite material according to the present embodiment is used, charging and discharging for a long period of time becomes possible, and in applications where such characteristics are required, for example, stationary lithium ion batteries for electric vehicles, homes, etc. It can be used effectively.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
Description
本実施形態に係る黒鉛材料は、炭素網面の広がりと、積層のズレとの比として定義したLc(112)/Lc(006)が0.08以上0.11以下の範囲となっている。ここで、Lcは、X線広角回折線から算出されるc軸方向への結晶子の大きさであり、Lc(112)/Lc(006)は歪みのパラメータである。この黒鉛材料では、a軸、c軸方向に歪みを持つ結晶子がランダムな方向に向いており、Lc(112)/Lc(006)が0.08以上0.11以下となっているので、リチウムイオン二次電池の負極材料として用いた場合に、リチウムが黒鉛粒子内部に挿入された際の膨張率を、歪みの小さい黒鉛粒子を負極材料として用いる場合に比べて小さくすることができる。Lc(112)/Lc(006)は、好ましくは0.085以上0.108以下である。
原料となる炭素質材料としては、石油系非針状コークスを用いる。偏光顕微鏡で観察した断面において、光学等方性組織が均等に分散した上で75%以上、より好ましくは85%以上存在し、且つ遷移金属含有量の合計が1000ppm以上2500ppm以下であり、窒素含有量が1wt%以上4wt%以下であるものを使用する。光学等方性組織が75%未満のコークスは結晶子が発達しすぎるので原料として適さない。
ここで、L:結晶の大きさ(nm)
K:形状因子定数(=1.0)
λ:X線の波長(=0.15406nm)
θB:ブラッグ角
β0:半値幅(補正値)
d=λ/(2sinθ) ・・Braggの式を変形したもの
ここで、d:面間隔(nm)
λ:測定に用いたCuKα線波長(=0.15418nm)
θ:回折角度(補正値)
黒鉛材料のLc(006)およびLc(112)、C0(006)を実際に測定した結果は、表2に示された通りである。
本開示の実施形態において、コークスの光学等方性組織率は以下のようにして調査する。まず、内容積28ccのプラスチック製サンプル容器の底に2g程度の観察用試料を乗せる。冷間埋込樹脂(商品名:冷間埋込樹脂#105,製造会社:ジャパンコンポジット(株))に硬化剤(商品名:硬化剤(M剤);製造会社:日本油脂(株))を加え30秒間スパチュラで混合する。得られた混合物(7mL程度)を前記サンプル容器に高さ1.2cmになるまでゆっくりと流し入れ、1日間静置して凝固させる。
偏光顕微鏡で観測した画像をキーエンス製デジタルマイクロスコープVHX-2000に取り込む。選択した倍率の画像を、観察角度0度と45度においてそれぞれ同じ地点から正方形の領域(100μm四方)を切り抜き、その範囲内の全粒子について以下の解析を行い、平均を求めた。解析に用いる倍率は500倍とした。光学異方性ドメインは結晶子の向きにより色が変化する。一方、光学等方性ドメインは常に同じ色を示す。この性質を用いて、色が変化しない部分を二値化イメージにより抽出し、光学等方性部分の面積率を算出する。二値化する際には、しきい値を0~34の部分と239~255の部分をピュアマゼンダと設定した。尚、黒色部分は空隙とする。
日立レシオビーム分光光度計U-5100を用いて発光分光分析法に従って定量分析した。測定結果は表1に示す通りである。
JIS M8813(セミミクロケルダール法)に従って分析した。測定結果は表1に示す通りである。
黒鉛粒子試料について、バナジウム等の遷移金属、窒素の分析、格子面間隔、結晶子の大きさ、平均粒子径の測定を行った。
SPS-5000(セイコー電子工業製)を用い、ICP(誘導結合高周波プラズマ発光分析)法により試料に含まれるバナジウムをはじめとする遷移金属を定量分析した。各金属含有率の合計値を不純物として表3に記載している。
TC-600(LECO社製)を用い、不活性ガス搬送融解-熱伝導度法によって定量分析した。
X線回折 学振法(「炭素」、1963年、[No.36]、p25-34)に従って測定した。
レーザー回折散乱式粒度分布測定装置LMS-2000e((株)セイシン企業製)を用いて測定した。
組立式セルを用いて、単極の電池評価を行った。
黒鉛粒子1質量部に呉羽化学製KFポリマーL1320(ポリビニリデンフルオダイド(PVDF)を12質量%含有したN-メチルピロリドン(NMP)溶液品)0.1質量部を加え、プラネタリーミキサーにて混練し、主剤原液とした。
主剤原液にNMPを加え、粘度を調整した後、高純度銅箔上にドクターブレードを用いて75μm厚に塗布した。これを小型ロールプレスを用いて、電極に対し1×103~3×103kg/cmとなるようにプレスした。さらにこれを120℃、1時間真空乾燥し、組立式セル用18mmφ、またはラミネートセル用に打ち抜いた。
下記のようにして組立式セルを作製した。尚、以下の操作は露点が-80℃以下の乾燥アルゴン雰囲気下で実施した。
代表的な実施例である後述の実施例1、2、4及び代表的な比較例である比較例2、10に係る黒鉛材料を用いてそれぞれ作製したリチウム電池の初期充放電特性を下記条件にて測定した。
充放電サイクル評価はラミネートタイプのフルセル(正極:市販の三元系正極材、負極:本願実施例又は比較例)を用いて行った。
負極は前記単極評価時同様にペースト調製を行った。正極ペーストは以下のようにして調製した。
主剤原液にNMPを加え、粘度を調整した後、高純度銅箔上にドクターブレードを用いて75μm厚に塗布した。小型ロールプレスを用いてこれをプレスし、電極密度が2.8g/ccとなるよう調整した。さらにこの試料を120℃、1時間真空乾燥し、その後フルセル電極用打ち抜き型を用いて所定のサイズに打ち抜いた。
露点が-40℃に管理されたドライルーム内で、ラミネートセル用に打ち抜いた正極・負極両方の電極の端子部分に超音波溶接機でタブリードを溶接し、上記電極およびセパレータをラミネートフィルムの内部に設置し、電解液注液口以外を融着した後に、前記電解液を真空含浸させた。その後、残り一辺を融着してラミネートセルを組み立てた。
実施例1、2、4及び比較例2、10に係る黒鉛材料を用いて作製した前記ラミネートセルのサイクル特性を以下の条件で測定した。
コークスAを平均粒径(D50)が5μmとなるように上述の方法で粉砕、分級した後、2400℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定後、上記のように電池を作製し、単極での初期特性及びフルセルでのサイクル特性を測定した。
コークスAを平均粒径(D50)が12μmとなるように粉砕、分級した後、2400℃で熱処理して黒鉛材料を得た。得られた材料について実施例1と同様に各物性を測定後、電池を作製し、単極での初期特性及びフルセルでのサイクル特性を測定した。
コークスAを平均粒径(D50)が12μmとなるように粉砕、分級した後、2600℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスAを平均粒径(D50)が12μmとなるように粉砕、分級した後、2800℃で熱処理して黒鉛材料を得た。実施例1と同様に各物性を測定後、上記のように電池を作製し、単極での初期特性及びフルセルでのサイクル特性を測定した。
コークスAを平均粒径(D50)が12μmとなるように粉砕、分級した後、2250℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスAを平均粒径(D50)が12μmとなるように粉砕、分級した後、3000℃で熱処理して黒鉛材料を得た。得られた材料について実施例1と同様に各物性を測定後、電池を作製し、単極での初期特性及びフルセルでのサイクル特性を測定した。
コークスAを平均粒径(D50)が24μmとなるように粉砕、分級した後、2250℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスAを平均粒径(D50)が24μmとなるように粉砕、分級した後、2400℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスAを平均粒径(D50)が24μmとなるように粉砕、分級した後、2600℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスAを平均粒径(D50)が24μmとなるように粉砕、分級した後、2800℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスBを平均粒径(D50)が12μmとなるように粉砕、分級した後、2250℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスBを平均粒径(D50)が12μmとなるように粉砕、分級した後、2400℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスBを平均粒径(D50)が12μmとなるように粉砕、分級した後、2600℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスBを平均粒径(D50)が12μmとなるように粉砕、分級した後、2800℃で熱処理して黒鉛材料を得た。得られた材料について実施例1と同様に各物性を測定後、電池を作製し、単極での初期特性及びフルセルでのサイクル特性を測定した。
コークスBを平均粒径(D50)が24μmとなるように粉砕、分級した後、2400℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
コークスBを平均粒径(D50)が24μmとなるように粉砕、分級した後、2800℃で熱処理して黒鉛材料を得た。得られた材料について各物性を測定した。
実施例1~4及び比較例1~12に係る黒鉛材料の物性を測定した結果を表2に示す。また、図2は、表2に示す測定結果を表す図である。なお、図2に示す破線は実施例1~4に係る黒鉛材料の測定結果を囲んでいる。
11 負極
12 負極集電体
13 正極
14 正極集電体
15 セパレータ
16 外装
Claims (8)
- 炭素網面の広がりと、積層のズレとの比として定義したLc(112)/Lc(006)が0.08以上0.11以下の範囲であり、
X線広角回折線から算出される結晶子の大きさLc(006)が30nm以上40nm以下であり、
平均粒径が3μm以上20μm以下である、リチウムイオン二次電池負極用の黒鉛材料。 - 請求項1に記載のリチウムイオン二次電池負極用の黒鉛材料において、
遷移金属含有率の合計が100ppm以上2500ppm以下である、リチウムイオン二次電池負極用の黒鉛材料。 - 請求項2に記載のリチウムイオン二次電池負極用の黒鉛材料において、
バナジウムを50ppm以上含有している、リチウムイオン二次電池負極用の黒鉛材料。 - 請求項1~3のうちいずれか1つに記載のリチウムイオン二次電池負極用の黒鉛材料において、
結晶子中のリチウム吸蔵サイト量を示す値として定義したLc(006)/C0(006)が40以上60以下である、リチウムイオン二次電池負極用の黒鉛材料。 - 請求項1~4のうちいずれか1つに記載のリチウムイオン二次電池負極用の黒鉛材料が負極材料として用いられている、リチウムイオン二次電池。
- 光学等方性組織率が75%以上、遷移金属含有率の合計が1000以上2500ppm、窒素含有率が1wt%以上4wt%以下である石油系非針状コークスを粉砕及び分級することにより、前記石油系非針状コークスの平均粒径を3μm以上20μm以下の範囲に加工する工程と、
加工された前記石油系非針状コークスを2300℃以上2900℃以下の温度で黒鉛化する工程とを含む、リチウムイオン二次電池負極用黒鉛材料の製造方法。 - 請求項6に記載のリチウムイオン二次電池負極用黒鉛材料の製造方法において、
加工前の前記石油系非針状コークスの光学等方性組織率は85%以上である、リチウムイオン二次電池負極用黒鉛材料の製造方法。 - 請求項6又は7に記載のリチウムイオン二次電池負極用黒鉛材料の製造方法において、
前記黒鉛化工程で形成された黒鉛材料に含まれる遷移金属の含有率の合計が100ppm以上2500ppm以下である、リチウムイオン二次電池負極用黒鉛材料の製造方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201380034125.XA CN104412427B (zh) | 2012-06-29 | 2013-06-25 | 锂离子二次电池负极用石墨材料、使用了该石墨材料的锂离子二次电池以及锂离子二次电池用石墨材料的制备方法 |
US14/411,842 US9831490B2 (en) | 2012-06-29 | 2013-06-25 | Graphite material for negative electrode of lithium-ion secondary battery, lithium-ion secondary battery including the graphite material, and method of manufacturing graphite material for lithium-ion secondary battery |
EP13810733.9A EP2869370A4 (en) | 2012-06-29 | 2013-06-25 | GRAPHITE MATERIAL FOR NEGATIVE ELECTRODE OF LITHIUM ION RECHARGEABLE BATTERY, LITHIUM ION RECHARGEABLE BATTERY COMPRISING SAME, AND METHOD FOR PRODUCING GRAPHITE MATERIAL FOR LITHIUM ION RECHARGEABLE BATTERY |
KR1020157000515A KR20150030705A (ko) | 2012-06-29 | 2013-06-25 | 리튬이온 이차전지 음극용의 흑연재료, 이를 이용한 리튬이온 이차전지 및 리튬이온 이차전지용 흑연재료의 제조방법 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012-147954 | 2012-06-29 | ||
JP2012147954A JP5269231B1 (ja) | 2012-06-29 | 2012-06-29 | リチウムイオン二次電池負極用の黒鉛材料、それを用いたリチウムイオン二次電池及びリチウムイオン二次電池用の黒鉛材料の製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014002477A1 true WO2014002477A1 (ja) | 2014-01-03 |
Family
ID=49179138
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/003957 WO2014002477A1 (ja) | 2012-06-29 | 2013-06-25 | リチウムイオン二次電池負極用の黒鉛材料、それを用いたリチウムイオン二次電池及びリチウムイオン二次電池用の黒鉛材料の製造方法 |
Country Status (7)
Country | Link |
---|---|
US (1) | US9831490B2 (ja) |
EP (1) | EP2869370A4 (ja) |
JP (1) | JP5269231B1 (ja) |
KR (1) | KR20150030705A (ja) |
CN (1) | CN104412427B (ja) |
TW (1) | TWI591887B (ja) |
WO (1) | WO2014002477A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014156098A1 (ja) * | 2013-03-28 | 2014-10-02 | エム・ティー・カーボン株式会社 | リチウムイオン二次電池負極用の非晶質炭素材料及び黒鉛質炭素材料、それらを用いたリチウムイオン二次電池並びにリチウムイオン二次電池負極用の炭素材料の製造方法 |
JP2015178583A (ja) * | 2014-02-28 | 2015-10-08 | コスモ石油株式会社 | フィラー及びこれを含む組成物 |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6287078B2 (ja) * | 2013-11-05 | 2018-03-07 | 戸田工業株式会社 | ケイ素含有非晶質炭素材料及びリチウムイオン二次電池の製造方法 |
WO2015129669A1 (ja) * | 2014-02-28 | 2015-09-03 | コスモ石油株式会社 | 石油コークス微粉砕物、石油コークス微粉砕焼成物、ゴム配合物用フィラーおよびゴム配合物 |
KR102424526B1 (ko) | 2015-06-29 | 2022-07-25 | 에스케이온 주식회사 | 이차전지용 음극활물질의 제조방법과 이로부터 제조된 이차전지용 음극활물질, 및 이차전지용 음극활물질을 포함하는 리튬이차전지 |
KR102602524B1 (ko) | 2016-03-04 | 2023-11-16 | 에스케이온 주식회사 | 리튬 이차전지 |
KR102560654B1 (ko) | 2016-04-05 | 2023-07-27 | 에스케이온 주식회사 | 리튬 이차전지 |
CN106356530A (zh) * | 2016-07-26 | 2017-01-25 | 江西紫宸科技有限公司 | 用于锂离子电池的负极材料、制备方法、二次电池和用途 |
CN107619047A (zh) * | 2017-09-22 | 2018-01-23 | 江苏亮盈科技股份有限公司 | 一种各向同性复合型锂离子负极材料的制备方法 |
WO2019065018A1 (ja) * | 2017-09-28 | 2019-04-04 | 新日本テクノカーボン株式会社 | 黒鉛材料 |
JP6993216B2 (ja) * | 2017-12-25 | 2022-01-13 | 戸田工業株式会社 | ケイ素含有非晶質炭素材料、リチウムイオン二次電池 |
JP2021068491A (ja) * | 2018-01-30 | 2021-04-30 | 昭和電工株式会社 | 黒鉛材料、その製造方法及びその用途 |
CN109980200B (zh) * | 2019-03-21 | 2021-01-15 | 北京工业大学 | 一种晶畴弥散分布非晶体磷基负极材料及其制备方法 |
CN113086979A (zh) * | 2021-04-02 | 2021-07-09 | 广州鹏辉能源科技股份有限公司 | 石墨材料的制备方法、石墨材料及应用和锂离子电池负极材料 |
CN114538431A (zh) * | 2021-09-09 | 2022-05-27 | 万向一二三股份公司 | 一种用于锂电池的快充石墨负极材料及其制备方法 |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1012241A (ja) | 1996-06-21 | 1998-01-16 | Mitsui Mining Co Ltd | リチウムイオン二次電池用負極材料 |
JP2000313609A (ja) * | 1999-02-26 | 2000-11-14 | Nkk Corp | リチウムイオン二次電池用材料とその製造方法及び電池 |
WO2004034491A1 (ja) * | 2002-10-11 | 2004-04-22 | Fdk Corporation | 非水電解質二次電池、及びこの非水電解二次電池に用いる正極の製造方法 |
JP4171259B2 (ja) | 2001-09-26 | 2008-10-22 | Jfeケミカル株式会社 | 黒鉛質材料の製造方法、リチウムイオン二次電池用負極材料およびリチウムイオン二次電池 |
JP2011082054A (ja) | 2009-10-08 | 2011-04-21 | Osaka Gas Chem Kk | 負極炭素材用コークス、負極炭素材及びリチウムイオン電池 |
JP4738553B2 (ja) | 2009-10-22 | 2011-08-03 | 昭和電工株式会社 | 黒鉛材料、電池電極用炭素材料、及び電池 |
JP4877568B2 (ja) | 2005-02-24 | 2012-02-15 | 日立化成工業株式会社 | リチウム二次電池用負極材料の製造方法 |
JP4896381B2 (ja) | 2003-06-05 | 2012-03-14 | 昭和電工株式会社 | 電池電極用炭素材料、その製造方法及び用途 |
JP2012084360A (ja) * | 2010-10-08 | 2012-04-26 | Jx Nippon Oil & Energy Corp | 格子歪を有するリチウムイオン二次電池負極用黒鉛材料及びリチウムイオン二次電池 |
WO2012081439A1 (ja) * | 2010-12-13 | 2012-06-21 | Jx日鉱日石エネルギー株式会社 | リチウムイオン二次電池負極用黒鉛材料およびその製造方法、リチウムイオン二次電池 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6485864B1 (en) | 1999-02-26 | 2002-11-26 | Adchemco Corporation | Production process of material for lithium-ion secondary batteries, material obtained by the process, and batteries |
JP4781659B2 (ja) | 2003-11-06 | 2011-09-28 | 昭和電工株式会社 | 負極材料用黒鉛粒子、その製造方法及びそれを用いた電池 |
JP5033325B2 (ja) * | 2005-12-05 | 2012-09-26 | 昭和電工株式会社 | 黒鉛材料、電池電極用炭素材料、及び電池 |
EP1961700B1 (en) | 2005-12-05 | 2019-06-26 | Showa Denko K.K. | Method for producing graphite material |
JP5367521B2 (ja) | 2009-09-18 | 2013-12-11 | Jx日鉱日石エネルギー株式会社 | リチウム二次電池の負極用炭素材料及びその製造方法 |
TWI533495B (zh) | 2010-08-05 | 2016-05-11 | 昭和電工股份有限公司 | 鋰蓄電池用負極活性物質 |
-
2012
- 2012-06-29 JP JP2012147954A patent/JP5269231B1/ja not_active Expired - Fee Related
-
2013
- 2013-06-25 US US14/411,842 patent/US9831490B2/en not_active Expired - Fee Related
- 2013-06-25 CN CN201380034125.XA patent/CN104412427B/zh not_active Expired - Fee Related
- 2013-06-25 KR KR1020157000515A patent/KR20150030705A/ko not_active Application Discontinuation
- 2013-06-25 WO PCT/JP2013/003957 patent/WO2014002477A1/ja active Application Filing
- 2013-06-25 EP EP13810733.9A patent/EP2869370A4/en not_active Withdrawn
- 2013-06-28 TW TW102123342A patent/TWI591887B/zh not_active IP Right Cessation
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1012241A (ja) | 1996-06-21 | 1998-01-16 | Mitsui Mining Co Ltd | リチウムイオン二次電池用負極材料 |
JP2000313609A (ja) * | 1999-02-26 | 2000-11-14 | Nkk Corp | リチウムイオン二次電池用材料とその製造方法及び電池 |
JP4171259B2 (ja) | 2001-09-26 | 2008-10-22 | Jfeケミカル株式会社 | 黒鉛質材料の製造方法、リチウムイオン二次電池用負極材料およびリチウムイオン二次電池 |
WO2004034491A1 (ja) * | 2002-10-11 | 2004-04-22 | Fdk Corporation | 非水電解質二次電池、及びこの非水電解二次電池に用いる正極の製造方法 |
JP4896381B2 (ja) | 2003-06-05 | 2012-03-14 | 昭和電工株式会社 | 電池電極用炭素材料、その製造方法及び用途 |
JP4877568B2 (ja) | 2005-02-24 | 2012-02-15 | 日立化成工業株式会社 | リチウム二次電池用負極材料の製造方法 |
JP2011082054A (ja) | 2009-10-08 | 2011-04-21 | Osaka Gas Chem Kk | 負極炭素材用コークス、負極炭素材及びリチウムイオン電池 |
JP4738553B2 (ja) | 2009-10-22 | 2011-08-03 | 昭和電工株式会社 | 黒鉛材料、電池電極用炭素材料、及び電池 |
JP2012084360A (ja) * | 2010-10-08 | 2012-04-26 | Jx Nippon Oil & Energy Corp | 格子歪を有するリチウムイオン二次電池負極用黒鉛材料及びリチウムイオン二次電池 |
WO2012081439A1 (ja) * | 2010-12-13 | 2012-06-21 | Jx日鉱日石エネルギー株式会社 | リチウムイオン二次電池負極用黒鉛材料およびその製造方法、リチウムイオン二次電池 |
Non-Patent Citations (6)
Title |
---|
"Modem Carbon Material Experimental Technology (Analysis part), The Carbon Society of Japan", 2001, SIPEC CORPORATION, pages: 1 - 8 |
CARBON, 1963, pages 25 - 34 |
CARBON, 2006, pages 52 - 60 |
ELECTROCHEMISTRY (DENKI KAGAKU, vol. 61, no. 12, 1993, pages 1383 |
J. ELECTROCHEM. SOC., vol. 137, no. 7, 1990, pages 2009 - 2013 |
See also references of EP2869370A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014156098A1 (ja) * | 2013-03-28 | 2014-10-02 | エム・ティー・カーボン株式会社 | リチウムイオン二次電池負極用の非晶質炭素材料及び黒鉛質炭素材料、それらを用いたリチウムイオン二次電池並びにリチウムイオン二次電池負極用の炭素材料の製造方法 |
JP2014194852A (ja) * | 2013-03-28 | 2014-10-09 | Mt Carbon Co Ltd | リチウムイオン二次電池負極用の非晶質炭素材料及び黒鉛質炭素材料、それらを用いたリチウムイオン二次電池並びにリチウムイオン二次電池負極用の炭素材料の製造方法 |
JP2015178583A (ja) * | 2014-02-28 | 2015-10-08 | コスモ石油株式会社 | フィラー及びこれを含む組成物 |
Also Published As
Publication number | Publication date |
---|---|
US20150147657A1 (en) | 2015-05-28 |
JP2014011085A (ja) | 2014-01-20 |
TW201409811A (zh) | 2014-03-01 |
TWI591887B (zh) | 2017-07-11 |
EP2869370A4 (en) | 2016-08-31 |
JP5269231B1 (ja) | 2013-08-21 |
CN104412427A (zh) | 2015-03-11 |
EP2869370A1 (en) | 2015-05-06 |
CN104412427B (zh) | 2017-05-10 |
US9831490B2 (en) | 2017-11-28 |
KR20150030705A (ko) | 2015-03-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5269231B1 (ja) | リチウムイオン二次電池負極用の黒鉛材料、それを用いたリチウムイオン二次電池及びリチウムイオン二次電池用の黒鉛材料の製造方法 | |
KR101820071B1 (ko) | 리튬 이차 전지의 음극용 탄소 재료 및 그 제조 방법 | |
JP5439701B2 (ja) | リチウムイオン二次電池用負極材、該負極材を用いたリチウムイオン二次電池用負極およびリチウムイオン二次電池 | |
US9214666B2 (en) | Graphite material with lattice distortion for use in lithium-ion secondary battery negative electrodes, and lithium-ion secondary battery | |
US20170057825A1 (en) | Artificial graphite material for lithium ion secondary battery negative electrode, and method for producing same | |
US10388984B2 (en) | Method for producing graphite powder for negative electrode materials for lithium ion secondary batteries | |
US20160056464A1 (en) | Amorphous Carbon Material And Graphite Carbon Material For Negative Electrodes Of Lithium Ion Secondary Batteries, Lithium Ion Secondary Battery Using Same, And Method For Producing Carbon Material For Negative Electrodes Of Lithium Ion Secondary Batteries | |
JP5728475B2 (ja) | リチウムイオン二次電池負極材料用原料炭組成物 | |
JP5590159B2 (ja) | リチウムイオン二次電池用負極材、その製造方法、該負極材を用いたリチウムイオン二次電池用負極およびリチウムイオン二次電池 | |
JP5615673B2 (ja) | リチウムイオン二次電池負極用非晶質系炭素材料の製造方法及びリチウムイオン二次電池 | |
CN114424368A (zh) | 负极活性材料、制备负极活性材料的方法、包含其的负极和锂二次电池 | |
JP7009049B2 (ja) | リチウムイオン二次電池負極用炭素材料、その中間体、その製造方法、及びそれを用いた負極又は電池 | |
US20230307641A1 (en) | Negative electrode active material, and negative electrode and secondary battery which include the same | |
JP2011216231A (ja) | リチウムイオン二次電池用炭素材料及びそれを用いた電極 | |
JP2023130725A (ja) | 負極活物質、リチウムイオン二次電池用負極及びリチウムイオン二次電池 | |
JP2023538318A (ja) | 負極活物質、これを含む負極および二次電池 | |
EP4357301A1 (en) | Method for preparing negative electrode active material, negative electrode, and secondary battery |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13810733 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14411842 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2013810733 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20157000515 Country of ref document: KR Kind code of ref document: A |