TW587350B - Composite graphite material and production method thereof, negative electrode material using the material, negative electrode and lithium ion rechargeable battery - Google Patents

Abstract

The invention provides a composite graphite material, which provides structure that contains graphite B with lower crystallization outside graphite A than graphite A and part of the surface of graphite B contains graphite C with lower crystallization than the graphite B. Aside from this, the invention further provides the production method of the composite graphite material and innovation of its purpose. The composite graphite material is adapted to the negative electrode and negative electrode material for lithium ion rechargeable battery so that the performance disregarded when conventionally considering graphite for lithium ion rechargeable battery will be accommodated, i.e. both the high initial rechargeable and dissipation efficiency and large dissipation of lithium ion rechargeable battery are taken into account.

Description

(1) 587350 玖, description of the invention [invented the secondary battery and the same graphite this composite stone [prior art in recent years in the battery-type secondary high-energy dense, positive electrode produced by decomposition, shape. The upper potential is equal to 2 3 4 3 3 < graphite surface (in this case (inter) a; the technical field due to graphite) is about the discharge |% — ♦ Large and high initial discharge efficiency lithium ion II Its constituent material. For n / -v body, (is composed of at least three kinds of crystalline composite stones that are not formed. Raw mouth ink material, its preparation method, and use.

The negative phase of the ink material. &Amp; _ V 1% yttrium, negative electrode and thallium ion secondary battery). In the future, with the miniaturization of electronic equipment and the improvement of performance, the demand for intermediary storage is also increasing. Compared with other types of batteries', lithium-ion secondary batteries can be promoted by increasing the voltage, and are therefore widely used. Lithium-ion secondary batteries have negative and non-aqueous electrolytes as the main constituent elements. Non-aqueous electricity generates clock ions and migrates between the negative and positive electrodes to form a secondary battery during charging and discharging. 'The negative electrode material of the above lithium-ion secondary battery is a carbon material using carbon material A, and it has excellent discharge properties, large discharge capacity, and the most potential for development. Please refer to Japanese Patent Publication No. 62. . 'The degree of development of the three-dimensional crystal regularity derived from its condensed polycyclic (C ndensed-ing) hexagonal mesh (called the carbon mesh surface) is known as the degree of development' can be easily interlayered / er of lithium) Forms stable compounds. (Therefore, there are local crystallinity indicated in research reports, and a large amount of (2) lithium can be inserted into the interlayer of the carbon mesh surface, so the discharge can be increased) (eg, Japan Electrical and Industrial Chemistry Association, 993, 6) (2) 5] 3 8 3 etc. reports). < It has also been reported that various layer structures formed by the amount of lithium interposed between the layers of the fe mesh surface can generate an average and nearly high lithium metal potential in the areas where they coexist ^ 1993 hEIectrochem-Soc *; Vol_M0 , 9,2490, etc.). Therefore, when used as an assembled battery ', extremely high output power can be obtained. In general, the theoretical capacity when graphite is used as the anode material is ultimately based on the discharge of the best graphite interlayer compound Li C6 formed by graphite and lithium, with a maximum discharge of 37 2 m A h / g . [However, in a lithium ion secondary battery using graphite as a negative electrode material, if the crystallinity of the graphite is too high, it is easy to cause side effects such as decomposition of the electrolyte when the graphite is charged for the first time. This side effect will cause the decomposed derivatives to continue to accumulate on the graphite surface until the formed graphite electrons cannot move directly to the thickness of the solvent). As the side effect during the first charging has nothing to do with the battery response, during the first discharging process, the so-called "irreversible capacity" that cannot release the discharged electricity will be significantly increased. In other words, it means that the ratio of the first charge amount to the first discharge amount (referred to as the first discharge efficiency in this case) is inconsistent (such as J.E in 1970] ectrocheni.Soc., Vol. 1] 7 22 2 and so on. The irreversible capacity is shown in the following calculation formula: Irreversible capacity = first charge capacity-first discharge capacity. In addition, there are reports that co-insertion of solvent molecules and lithium ions will cause the film surface layer to peel off, and the exposed graphite surface and electrolyte after peeling off. Reactions lead to poor initial charge and discharge efficiency (eg JE ectrochem. Soc. 990, Vol. 13 7 2009, etc.). Winter (3) (3) 587350 As a means known in the industry, a method for adding the positive electrode material of a secondary battery is used to solve the above-mentioned initial charge-discharge rate failure. However, the addition of excess positive electrode material 'will cause a new problem of lowering the energy density. As described above, in a lithium-ion secondary battery using graphite as a negative electrode material, 'for a discharge amount that also depends on the crystallinity of graphite and the initial discharge efficiency, PZ?', The requirement for both a large discharge level and a high initial discharge rate is The opposite. \\ Therefore, a kind of double-layer structure using low-crystalline graphite or carbon, which is helpful for increasing the initial discharge efficiency, is adopted as the core, and high-crystalline graphite which is good for increasing the discharge capacity is used to solve the above problems because Low-crystalline carbon has a low discharge capacity, so it has low decomposition reactivity with the electrolyte. The double-layer carbon material with different crystallinity is most different from the traditional technology in that: (1) the use of dioxane, Low crystallinity derived from the thermal decomposition of benzene and other organic compounds covers the surface of highly crystalline graphite as the core (for example, Japanese Patent Publication No. 4-3 6 8 7 7 8 and Japanese Patent Application Laid-Open No. 5-2 7 5 0 7 Bulletin 6). (2) High-crystalline graphite coated or soaked with liquid asphalt as the core is sintered at a temperature of about OO ° C to form low-crystalline graphite on its surface (for example, Japanese Patent Laid-Open No. 5 "21 〇66, Japanese Patent Application Laid-Open No. 5-2 1 7604, Japanese Patent Application Laid-Open No. 6-84 5 168, Japanese Patent Application Laid-Open No. II-54112 · 3, and Japanese Patent Application Laid-Open No. 2000-229924. -9- (4) (4) 587350 (3) Use carbon that can form graphite by sintering at about 300 ° C (referred to as easily graphitizable carbon in this case), such as coke, in the gaseous or liquid oxidation In a natural environment, graphite is formed after oxidation treatment at a temperature of about 300 ° C (for example, Japanese Unexamined Patent Publication No. 10- 3 2 66 1 1 and Japanese Unexamined Patent Publication No. 10_ 2] 8 6] 5 6). (4) Those who combine the methods ()) to (3) above (for example, Japanese Patent Application Laid-Open No. 0- 2] 4 6 1 5 and Japanese Patent Application Laid-Open No. 0-2 8 4 0 8 0). However, no matter which of the above-mentioned methods can not fully meet the demand standard for increasing the discharge capacity in recent years. However, from the viewpoint of industrial production, due to the cumbersome production process of the above (1) and (4), the production cost is too high and there are difficulties in production. In addition, it is difficult to control the thickness of the low crystalline carbon on the surface, which causes the problems of unstable powder characteristics such as specific surface area and bulk density, and unstable battery characteristics of discharge capacity and initial discharge efficiency. . In addition, in the method (2) above, when sintering is performed at 100 ° C, the low-crystalline carbons on the surface layer will be fused, and in a state where they are disintegrated, the low-crystallinity on the surface layer will be low. Sexual carbon will be exfoliated from the graphite as the core, leading to the problem of poor powder characteristics such as specific surface area and bulk density, and poor battery characteristics such as discharge capacity and initial discharge efficiency. In the above methods (1) and (2), since the expansion and contraction reactions of the core graphite and the surface of low-crystalline carbon during charging and discharging are not consistent, as the number of charging and discharging increases, The low-crystalline carbon exfoliation taught to the surface layer causes the same problems as described above. -10- (5) (5) 587350 In the method (3) above, in order to obtain high initial charge and discharge efficiency, the crystallinity of the highly oxidized and thick surface layer must be reduced, and the surface layer itself and the graphite inside it must also be reduced. The crystallinity of the carbonized carbon leads to a problem that sufficient crystallinity cannot be obtained even if graphitization is formed at a high temperature, and a problem arises in that the discharge amount is lowered. The discharge capacity of the cell is determined by increasing the discharge capacity j of each graphite volume constituting the negative electrode. QS, in order to increase the discharge capacity of the battery, the most effective method is to charge graphite with a high discharge capacity per unit weight (m A h / g) into a high density method). Density to form the negative electrode will cause a tendency that the adhesion force between graphite and the low-crystalline carbon of the surface layer is insufficient as described in (1) and (2) above. Once this is done, the coating of low crystalline carbon will be peeled off from the surface of graphite, so that the surface of graphite with high reactivity with the electrolyte will be exposed, leading to a problem of lowering the initial discharge efficiency. The object of the present invention is to obtain a lithium ion primary battery that can achieve a large discharge capacity and high initial charge-discharge efficiency that cannot be taken into account when using graphite as the anode material of a lithium ion j-primary battery. Specifically, an object of the present invention is to provide a graphite material and a manufacturing method thereof that can simultaneously satisfy two properties, and a negative electrode material, a negative electrode, and a lithium ion secondary battery using the composite graphite material. In addition, the present invention also provides a manufacturing method that can suppress fusion during production of a composite graphite material and has excellent productivity. [Summary of the invention] In other words, the composite graphite material of the present invention has a structure of: -11-(6) 587350 The outside of graphite A has graphite B ', which is lower in crystallinity than the graphite A, and the graphite B At least a part of the outer surface of graphite is graphite C, which is less crystalline than graphite B. The "composite graphite material" preferably has a structure in which the graphite B is coated with the graphite A and the graphite c is coated with the graphite B. Regardless of the above-mentioned graphite materials, spherical or ellipsoidal granules are most suitable. In addition, regardless of the above-mentioned graphite material, the interplanar spacing of the carbon mesh surface layer (d㈣J is 0.3 3 65 or less), the size (Lc) of the crystal in the c-axis direction is 40 nm or more, and the peak of the Raman spectrum

値 intensity U】 36. ) The ratio 値 (I) to 36g / I to 58G with respect to the peak 値 intensity (1) of 158⑽⑽] is 0.05 or more and 0.30 or less (regardless of which of the above graphite materials, flake graphite is the most As appropriate.;)

The test is most suitable for the above-mentioned graphite A. In addition, no matter which type of graphite A, the surface interval (dG () 2) of the carbon mesh surface layer is preferably less than 0 33 • ϋ J 3 b n m or less. i Regardless of which of the above graphite materials, the interplanar spacing (dG () 2) of the carbon mesh surface of the aforementioned graphite B is preferably less than 0.3 37 nm, and ‘this case also provides a composite containing any of the above-mentioned items.

A negative electrode material for a lithium ion secondary battery using an ink material. X 'The present invention also provides a negative electrode for a lithium ion secondary battery containing the composite stone SS material described in any one of the above items. The present invention also provides a secondary battery including any one of the above. (7) Finally, the present invention provides a method for manufacturing a composite graphite material, which is used to produce a graphite material having a lower crystallinity on the outside of the graphite A than the graphite A. Graphite B, and at least a part of the outer surface of the graphite B is a composite graphite material having a structure having a lower crystalline portion than the graphite B. The manufacturing method includes: A process of carbon with easy graphitization characteristics; a process of performing the first sintering on the adherend to such an extent that the carbon with easy graphitization characteristics is substantially ungraphitized; for the first sintered body, A process of reforming by applying mechanical energy substantially without pulverizing; performing a second sintering process on the reformed body until the carbon having easy graphitization characteristics has been substantially graphitized. In the above manufacturing method, the graphite is most preferably flaky graphite. Moreover, in any of the above-mentioned manufacturing methods, the interplanar spacing (d002) of the carbon network surface layer of the graphite is preferably less than 0.3 35 8 nm. Regardless of which of the above-mentioned manufacturing methods, the aforementioned carbon having easy graphitization characteristics is preferably at least one selected from the group consisting of tar, pitch, and mesophase. Furthermore, in any of the above-mentioned manufacturing methods, it is preferable to have a process of granulating the graphite before performing the aforementioned adhesion process. Regardless of which of the above-mentioned manufacturing methods, the aforementioned attachment process is preferably made by melting, dissolving, or dispersing at least one of the selected methods to first convert the carbon having an easily graphitizable property into a liquid state, and then attach it to The graphite. -13- (8) (8) 587350 In any of the above-mentioned manufacturing methods, it is preferable that the first sintering process is such that the volatile components remaining in the carbon having easy graphitization characteristics become 2.0% by mass or more 20% by mass or less. Finally, no matter which of the above-mentioned manufacturing methods, it is preferable to have a process of disagglomerating the aggregates above the secondary aggregation after the first sintering process described above. [Embodiment] Next, the present invention Explain in detail. The composite graphite material of the present invention has a structure in which a graphite B having a lower crystallinity than the graphite A is outside the graphite A, and at least a part of an outer surface of the graphite B has crystallinity. Graphite C is lower than this graphite B. According to this, the composite graphite material of the present invention firstly has a so-called primary structure, which has graphite B on the outside of graphite A having lower crystallinity than graphite A. The "outer side of graphite A" referred to herein may be the whole or a part of the outer surface of the graphite A. Therefore, the primary structure can also form a plurality of forms in which the graphite A is covered by the outer graphite B. For example, two graphites A and graphite B can be sandwiched into a dumbbell shape. In any of the above states, it does not matter whether the graphite B is locally discontinuous or the graphite A is partially exposed without interruption. The state arrangement of the above primary structure is as follows: (1) The state where graphite B is attached to one graphite A, or graphite B is coated with one graphite A. -14- (9) (9) 587350 (2) A plurality of states (1) above are gathered. (3) A plurality of graphites A are covered with graphite B. (4) A plurality of states (3) above are gathered. You can combine any one or more of these states. Among them, the state of (3) is the best / especially the one in which a plurality of graphites are coated with graphite B and form an approximately spherical shape is most suitable. (The graphite c constituting the composite graphite material in the present invention need only exist once. A part of the outer surface of the graphite B of the structure may suffice. Among them, it is best that the graphite B is present on the entire outer surface of the graphite B and is integrated with the graphite B. Moreover, the graphite described in the present invention is not only the graphite itself, There are some carbonaceous materials used to make the graphite bond with each other, and the industry calls them "lithocene materials." In the present invention, the crystallinity of graphite A is higher than that of graphite b. For example, graphite A may be Artificial graphite, natural graphite, expanded graphite, graphite carbon fiber, graphitized carbon black, etc.) Qi also contains mesophase sintered carbon (raw materials are tar and pitch) 'mesophase spheroids, coke (green coke, wet coke ash, bitumen Graphite that is easily graphitizable carbon such as coke, natural coke, petroleum coke, etc. after being treated at about 3 00 (TC. Among them, the most crystalline graphite that helps to obtain a large discharge capacity is the best, especially natural stone Ink is best ) The crystallinity of L graphite can be judged by the interplanar spacing (docn) of the carbon mesh surface layer in the X-ray wide-angle diffraction method. In other words, CuK light is used as the X light source, and local purity silicon is used as the standard material. Measure the diffraction peak 値 of graphite (), and calculate d㈣2 from the position of the peak 値. The calculation method is (10) The specific method can be applied according to the "Study method" (measurement method developed by the Japan Society for the Promotion of Science, Committee I 17), such as "Carbon Fiber", pages 7 3 3 ~ 7 4 2 Company, March 1986). [In the present invention, although it is not particularly limited that the crystallinity of graphite A must be higher than that of graphite B, it is most appropriate that d 002 is less than 0. 3 3 5 8 nm.丨 The shape of graphite A can be spherical, ellipsoid, scale, block, plate, fibrous, and granular. Even those made from blocky graphite are fine. The most suitable graphite A is flaky graphite. Among them, those in which a plurality of flaky graphites are aggregated or granulated and formed into a spherical or ellipsoidal shape are the best. In this case, although in the composite graphite material finally obtained, graphite A is preferably formed into a spherical or ellipsoidal shape, if a plurality of flaky graphites are granulated in advance and formed into a compact spherical shape Or ellipsoidal graphite A is more suitable. Specifically, graphite A granulated into a dense spherical or ellipsoidal shape preferably has a porosity of less than 50% by volume, and more preferably less than 30% by volume. If the porosity of the granules is less than 50% by volume, an appropriate amount of easily graphitizable carbon will be formed during subsequent processing, and a sufficient discharge amount can be easily obtained. Moreover, once voids are difficult to remain in the composite graphite material, even if a high-density negative electrode is produced, there is a possibility that the composite graphite material is cracked and the initial discharge efficiency may decrease. The particle diameter of graphite A is more suitable from 1 to 100 μΓΠ based on volume conversion, and 2 to 30 μηι is the most appropriate. -16- (11) The ratio of graphite A to graphite B is In terms of mass units, 'graphite A is preferably 50 to 1,000 mass units, and the proportion of graphite a is again 100 to 2000 mass units.) The graphite B of the present invention is applicable to any graphite as long as it is less crystalline than graphite a. For example, "(graphite B may be a graphitizable compound of graphitizable carbon. The so-called graphitizable carbon refers to carbon that is converted to graphite by calcination at about 300 ° C. ≫ Graphitizable The components in carbon can be obtained by increasing the proportion of QI (Primary Quinoline Insoluble) or reducing the temperature during graphitization to obtain graphite B, which is less crystalline than graphite A. Among them, tar and pitch are used as raw materials. After calcining to form a mesophase, it is most suitable to form graphitization at about 3 0 0 ° C. The crystallinity of graphite b is preferably d 〇2 is less than 0.33 370 nm. The present invention For composite graphite materials, at least in part of the outer surface of graphite B constituting the above-mentioned primary structure, there is graphite c that is less crystalline than graphite b. For example, @GraphicC can be used for the graphitizable carbon as the raw material of graphite b After applying the mechanical properties such as compression, shearing, impact, and / or friction to the modification treatment, it is produced or formed by generating graphitization. 辉 Hui The graphitizable carbon obtained by the above modification treatment), ( As its surface is at least partially Disordered crystal structure, the crystallinity than the graphite after the formation of the modified process of graphitization of the graphite C lower ^ β). The graphite C constituting the composite graphite material of the present invention can be formed on a partial surface of the graphite B constituting the primary structure by the method described above. Of course, graphite C obtained by other methods can also be made to exist on the surface of graphite β by means such as adhesion or insertion. From the viewpoint of production efficiency, the method of integrally forming graphite C on the surface of stone -17- (12) ink B is more efficient than the manufacturer using other processes. As long as a composite graphite material having the aforementioned shape can be produced, any method is applicable to the composite graphite material of the present invention, and there is no particular limitation. In order to facilitate the understanding of the present invention, a manufacturing method for manufacturing the above-mentioned composite graphite material is enumerated, and a part of the manufacturing method disclosed in the present invention will be described below. The manufacturing method disclosed in the present invention (is used to produce graphite B which has crystallinity lower than that of graphite A on the outside of graphite A, and at least a part of the outer surface of graphite B has crystallinity The composite graphite material having a structure lower than that of the graphite B has a manufacturing method of: a process of attaching carbon having easy graphitization characteristics on the outside of the graphite; so that the carbon having easy graphitization characteristics substantially 尙The degree of non-graphitization, the first sintering process is performed on the adherend; the first sintered body is modified by applying mechanical energy in a manner that does not substantially pulverize; and the modified body The second sintering process is performed until the carbon having easy graphitization characteristics has been substantially graphitized. Hereinafter, this is referred to as "the method of the present invention." (According to the method of the present invention, graphite A can be easily obtained > Graphite B > The crystalline composite graphite material of the present invention '). In particular, the composite body integrally formed without the interface between graphite B and graphite C is opposite. The crystallinity of graphite B and graphite C is lower. Especially after the formation of graphite B, it is best to exist in a thin layer. When graphite C is formed by the above method, although the boundary between graphite B and graphite C is formed, It is not obvious that the thickness of graphite C cannot be constrained, but the thickness of graphite C is -18- (13) 〇 · Ο 1 ~ 5 μm is most suitable. In the present invention, graphite A, graphite, and graphite C The crystallinity must be maintained in the order of Graphite A > Graphite B > Graphite C. (^ In this way, while maintaining the original high discharge capacity of Graphite A, the characteristics of high initial discharge efficiency possessed by Graphite C are maintained> In addition, by the action of graphite B contained tightly, the above excellent battery characteristics can be maintained even in a state where the composite graphite material is charged at a high density to form a negative electrode. In the present invention, the composite graphite The crystallinity of the outer surface of the material, that is, the crystallinity of graphite C, can be evaluated by using Raman spectroscopy with argon laser. In other words, the nine lattice vibrations of the graphite structure correspond to the carbon mesh surface. 1 58 of E2g type with internal lattice vibration C1rT] near the Raman spectrum, and the reaction mainly exists in disordered crystal structures such as crystalline defects and uneven layers in the surface layer. The Raman spectrum near 1 5 8 0 cm · 1 can be used with a wavelength of 5 1 4 · 5 A Raman spectrometer (manufactured by JASCO Corporation, model: NR 1 1 0 0) is used for measurement. The intensity ratio R (R = I136Q / I] 5 8 〇) 'and determined that the larger the intensity ratio is, the lower the surface crystallinity is. From the viewpoint of increasing the initial charge-discharge efficiency, the intensity ratio R is preferably g 0. 05. Based on the electrolyte decomposition reaction to reduce the surface layer crystallization on the surface of the slightly disordered composite graphite material. On the other hand, from the viewpoint of suppressing the decrease in the discharge amount to a minimum, R is preferably less than 0.30. In addition, the crystallinity of the entire composite graphite material can be determined by the same X-ray wide-angle diffraction method as the average 値. It can also be judged by the interplanar spacing (dou) of the carbon mesh surface layer and the dimension (Lc) in the C-axis direction of the crystal (14) 疋. That is, CuK α light is used as the χ light source, and high-purity silicon is used as a standard substance to measure the diffraction peak 値 ′ of graphite (002). Then, by using the position of the peak 値 and its half-width, d ^ 2 and Lc. In the overall composite graphite material of the present invention, the de () 2 is preferably lower than 0.365 nni, and the Lc is preferably higher than 40 nm. Among them, it is most suitable that dOO2 is lower than 0.32 62nm, and Lc is higher than 50nm. If hG2 is lower than 0.3 3 65 5 and Lc is higher than 40 40, the amount of doped lithium graphite as the composite graphite material of flat graphite composite graphite material becomes larger, so the composite of the present invention can be obtained. Particle diameter of graphite material. When the electrode material is used to adjust the battery characteristics, etc., a flat graphite material is selected as the lithium ion secondary average particle diameter of 5 to [00 μη], where the composite graphite material of the invention has a shape. ) Spherical or ellipsoidal electrolyte with excellent electrolyte injectability and retentivity, so it is very suitable for lithium. If flaky graphite is used as a representative, the average length and width of composite graphite materials with similar shapes can be easily formed. 2 or less is most suitable. Also, since the composite graphite material has a highly developed graphite structure, when the negative electrode material of a secondary battery is used, it has a large discharge capacity. For the visible use, select the design thickness and average particle diameter of the visible electrode when averaging is used. When the negative electrode material of the secondary battery of the present invention is used, its optimum level is most preferably 5 to 30 µm. It is best to form a composite graphite material that approaches the sphere as much as possible. Since it has a pole, it can improve the rapid discharge efficiency and the negative electrode material of the ion secondary battery. Provided that the granules of natural graphite are graphite spherical bonded graphite materials. The monthly ratio of this hair is preferably below 3, and it is expected to form a shape close to a sphere, so -20- (15) 587350 can form a very high bulk density. When the negative electrode is produced under a high bulk density state, it is not necessary to apply additional pressure, and it helps reduce problems such as stone damage. The bulk density is preferably higher than 0.5 g / cm3]: 0.7 g / cm3 or more is suitable, and the specific surface area of the composite graphite material of the present invention above i. G / cm3 is more suitable to match the characteristics of the secondary battery, and The paste-like characteristics of the negative electrode binder can be arbitrarily selected, and those having a BET specific surface area of less than 20 m2 / g or less have better lithium ion safety. Generally, a BET specific surface area of 0.3 to 5 m is more suitable for 3 m 2 / g, and the one with a BET specific surface area of less than 1 m 2 / g is most suitable. Next, the manufacturing method of the present invention described above will be described more clearly. In the method of the present invention, the graphitizable carbon adheres to the outside. In other words, it is only necessary to sandwich one or more graphites in sex carbon. This graphite corresponds to the graphite for graphite in the composite graphite material of the present invention, and it is most suitable that the interplanar spacing (dG () 2) of the carbon mesh surface layer is lower than the following. The easily graphitizable carbon is at least one selected from the group consisting of tar mesophases. Among them, it is preferable to select one of petroleum-based or petroleum-based heavy oil such as oil and asphalt as the mesophase substance formed by the primary sintering treatment. In this adhesion treatment, the easily graphitizable carbon is preferably formed into a liquid state by one of methods of dissolving or dispersing the carbon, and the ink is attached. For example, it is preferable that kneaded carbon and graphite in a molten state be kneaded under a reheated state to obtain a graphite high-density ink material which is intimately mixed with each other. Design of Lithium Ion II. — Secondary battery 2 / §, low. The detail of Xia Xia is compared with graphite's easy graphitization A. Therefore, 0.3 3 5 8 η, bitumen, and at least the coke are melted, and the stone is graphitized with a mixture of graphitizable and easily graphite -21-(16) (16) 587350 carbon. In this method, it is preferable that the heated kneaded material is cooled and solidified and then disintegrated 'and adjusted to a desired shape. Alternatively, a small amount of molten easily graphitizable carbon may be added to the graphite, and then granulated into a desired particle shape. Specifically, easily graphitizable carbon such as tar and pitch can be dissolved in benzene, toluene, quinine, medium tar, heavy tar, etc. to form a solution, and then the graphite can be immersed in it for heating and decompression to make it easy to graphitize. After the chemical carbon is attached to the graphite A, the solvent is removed by the way. In addition, it is not a problem that the adhered amount of the graphite to be formed of the graphitizable carbon is uneven, and the difference in the volatilization amount between the central portion and the surface portion does not matter. On the other hand, in the "method of the present invention", it is preferable to perform a graphite granulation treatment before the adhesion treatment. Since the composite graphite material of the present invention is most preferably spherical or ellipsoidal, graphite is also formed into this shape in conjunction. In other words, graphite A is most preferably spherical or ellipsoidal. It is best to use granules with a plurality of flaky graphite. As the graphite granulation method, a dry and wet granulation method is conventionally applied to a plurality of flaky graphites. It is also possible to use a binder during the granulation process. As the component of the binder, the above-mentioned easily graphitizable carbon can be used. The component of the adhesive may also be a component which can disappear in the subsequent secondary sintering. As long as it is within the range that does not impair the effect of the present invention ', it is easy to use the method of generating a graphite structure by using the secondary sintering. In addition, when tar or pitch is used as the easily graphitizable carbon, it is preferable to contain finer particles. The use of fine particles can reduce the melting and adhesiveness after one sintering ', which will facilitate the disintegration. As long as the melting -22- (17) (17) 587350 fusion bond is suppressed after one sintering, the outer side of graphite can be completely covered with easily graphitizable carbon, and the initial charge and discharge efficiency of the composite graphite material can be further improved in the end . For the tar, bitumen, or mesophase formed by one-time sintering of oleophilic tar, the adhesion of fine particles is lower as possible. Once it has adhesion, it will reduce the improvement effect of disintegration. The fine particles are preferably hydrophilic particles. Although the fine particles can be particles that react with carbon during the sintering process or remain in the composite graphite material after primary sintering, the fine particles or derivatives are preferably vaporized and decomposed before secondary sintering to avoid remaining in the composite Graphite material. Microparticles need only a small size and amount to achieve the effects of preventing melt-gluing and improving disintegrability. Therefore, the average particle diameter of the fine particles is preferably less than 1 μm. As long as it is less than [μm], it is not necessary to add a large amount of fine particles, and it does not cause problems such as degradation of battery performance such as electric capacity. The amount of fine particles used is most preferably 0% to 0% by mass of graphite B in the composite graphite material. Among them, 0.05 to 3% by mass is the best. When it is greater than 0.01% by mass, the improvement effect of disintegrability will be increased. When it is less than 10% by mass, the prepared composite graphite material will have an appropriate specific surface area and appropriate particles. Diameter, it is difficult to cause a decrease in the initial discharge / discharge efficiency. Particles that meet the above conditions, such as inorganic fine powders such as oxides, oxides, and titanium oxide; and carbon particles such as metal oxides and oxidized carbon black; and iron black, chrome yellow, zinc yellow, Yellow iron oxide, yellow iron, yellow titanium, iron oxide red, lead, zinc oxide, zinc white, lead sulfate, zinc-23- (18) barium white, titanium oxide, antimony oxide, silicon aluminum, glaze white, calcium sulfate, Pigments such as gypsum; and aluminum silicates such as kaolin, talc clay, sintered clay, hydrous aluminum silicate composites; and calcium carbonates such as chalk and chalk; and calcium and magnesium such as dolomite powder Carbonate, magnesite powder, base magnesium sulfate, and other magnesium sulfates; and calcium silicates such as limestone, water-containing sand acid brocade synthetic products; and magnesium silicates, such as talc and mica; and quartz Silicates such as powder, pulverized fossil acid, and diatomaceous earth; and resin pellets. In the method of the present invention, one of the foregoing substances may be used singly or in combination. Among them, inorganic fine powders such as silicon oxide, alumina, and titanium oxide, which are not reacted with easily graphitizable carbon, are produced by a gas phase method. Although there is no particular limitation on the mixing method of adding fine particles to easily graphitizable carbon, in this case, a method of dissolving fine particles in a solvent in advance, and then injecting the fine particle-containing solvent into molten tar or pitch to stir is used. . As the solvent, the aforementioned solvents can be used. In the method of the present invention, after the easily graphitizable carbon is attached to graphite, the adherend is sintered once, and the primary sintering does not cause the graphitizable carbon attached to the surface to be substantially graphitized . The degree that "substantial graphitization does not occur" refers to the state where the crystal structure can be unstable during the modification process in the next process, that is, the state where the molecular structure has fluidity. During this treatment, a number of graphitizable carbons undergo heavy condensation reactions. In this state, a suitable range can be shown by the amount of volatilization of the remaining easily graphitizable carbon. It is preferable that the volatile content of the easily graphitizable carbon after primary sintering is 2.0 mass% to -24- (19) or more and less than 20 mass%. Among them, it is more preferably 4 mass% to less than 15 mass%. In the present invention, the 'volatility' is measured in accordance with the fixed carbon method regulated by JIS K242 5 by the following method. Method for measuring the volatile amount of easily graphitizable carbon: Measure 1 g of the measurement object (easy graphitizable carbon) and place it in a crucible without a lid and heat it at 4 3 0 ° C for 3 0 minute. Next, the double-layered crucible was heated at 800 C for 30 minutes to remove the volatile amount, and the reduced portion was equal to the volatile amount. If the graphitizable carbon after primary sintering is expressed in other ways, 'the softening point (Mettler method) is higher than 3 60 ° C and the solid' quinone has an insoluble amount (QI) of 50 mass. % To 100% by mass, and more preferably 80% to 99.5% by mass. In the present invention, Q I is measured according to the specification of TI S K 2 4 2 5 using the following filtering method. QI measurement method: Dissolve powdery carbon material (easy-graphitizable carbon) in quinine, heat it at 7 5 ° C for 30 minutes, and then perform suction filtration under hot state. Rinse the residues in the order of quine and acetone. After each filtrate has formed a colorless state (by visual judgment), dry it and measure its quality to complete the entire QI (Quinoline insoluble). Among them, diatomite is used as a filter aid. The filter is a pot filter 1G4 specified by jlS R3 5 3 0. Graphitizable carbon with a large volatility or low QI can show the meltability during the graphitization by secondary sintering. The shape of this easily graphitizable carbon will change during secondary sintering due to the -25- (20) melting between the materials. Therefore, if the volatile content after primary sintering is less than 20% by mass, during the modification process using mechanical properties, it is easy to disturb the crystal destructuring of the surface layer, and it is easy to form stone blackening in the subsequent secondary sintering. . For this reason, it is preferable to reduce the amount of volatilizable carbon used in the present invention in a suitable range by one-time sintering. On the other hand, if the hair loss is small or the graphitizable carbon is weak, the above-mentioned melting characteristics are lost. As long as the volatile content is greater than 2.0% by mass, it is easy to form a crystalline structure on the outer surface of easily graphitizable carbon after applying mechanical properties, and form a suitable low-crystalline graphite after secondary sintering. . Accordingly, in the present invention, it is preferable that the volatile amount of the easily-to-tolerate carbon produced by one-time sintering is adjusted within a range from 2.0% by mass to less than 20% by mass. The primary sintering can be performed under any of reduced pressure, normal pressure, or increased pressure. The temperature of primary sintering is usually 300 to 200 ° C, and it is preferably carried out in a temperature range of 350 to 600 ° C. Although it is best to perform in a non-oxidizing environment, heat treatment can also be performed in a partially oxidizing environment. And one sintering can be performed in multiples. The sintering time is not particularly limited, and is about 0.5 to 100 hours. Although the shape of the sintered body subjected to primary sintering is not particularly limited, and may be any of granular, scaly, spherical, needle, and fibrous shapes, it is most suitable to be spherical or ellipsoidal. In a state where only the melted glue is formed after one sintering, various kinds of pulverizers can be used to disintegrate the melted glue. The disintegration method can adopt roller type, impact type, friction type, compression type, stone mortar type, dynamic conflict type, eddy current type, air flow type, shear type and -26- (21) (21) 587350 vibration type Crushers sold in various markets. In the method of the present invention, the primary sintered body obtained by the above-mentioned primary sintering is subjected to a modification treatment by applying a mechanical property amount that does not cause substantial pulverization. Through the modification treatment, a composite graphite material can be obtained after secondary sintering. The structure of the composite graphite material is: forming a graphite B ′ having lower crystallinity than the graphite A outside the highly crystalline graphite A and at least the graphite Graphite C, which is less crystalline than graphite B, is present on the local outer surface of b. In this manufacturing method, it is preferred that the primary sintered body is disintegrated and its shape is adjusted to an approximate finished product, and then mechanical properties are applied. That being said, it is also possible to apply a continuous mechanical energy amount when dissolving a fused colloid formed of a plurality of graphite and easily graphitizable carbon. The mechanical properties referred to in the present invention refer to various stresses such as compression, shearing, collision, and friction. This mechanical property is preferably applied to the outer surface of the easily graphitizable carbon after one sintering. If a general mechanochemical treatment is used to perform this kind of operation, the mechanical properties obtained will be greater than the power given by general stirring. However, at least the particles and aggregates of graphite (graphite A) constituting the primary sintered body should not be substantially damaged. Once excessive damage occurs, the initial charge-discharge rate tends to decrease. Specifically, it is preferable that the decrease rate of the average particle diameter of the primary sintered body due to the application of the mechanical properties is suppressed to 20% or less. The modification treatment can apply mechanical properties to the outer surface of the primary sintered body. Any device is applicable, and there are no restrictions on the structure and type. For example, the device for applying mechanical energy may be a pressure kneader, two kneaders such as -27- (22) (22) 587350 rotors, a rotary ball mill, a HYBRIDIZATION SYSTEM (trade name 'Nara (Produced by Nippon Kogaku Seisakusho), me CHAN 0 MICROS (trade name)

MECHANOFUSION SYSTEM (trade name, produced by H0S0KaWA MICRON GROUP), etc. In the above-mentioned device, it is best to use a difference in rotational speed and simultaneously provide a shearing force and a compressive force. For example, as shown in Figure 2 (a) and (b), Η 0 S 〇 K A W A MICRON GROUP MECHA NOFUSION S Y S TEM meets the above conditions. That is, 'the rotating drum as shown in FIG. 2 (b)] i, and internal components (internal screws) different from the rotating speed of the rotating drum 1] 1 can be used, and 2 can be used for a primary sintered body] 3 Cycle mechanism] 4 and the discharge mechanism j 5 device. In this device, as shown in FIG. 2 (a), the modification process can be performed by applying a centrifugal force to the primary sintered body [3] supplied to the rotating drum]] and the internal member 12] while repeating synchronization. The application of the compression force and the shearing force that causes a speed difference between the internal member 2 and the rotating drum η is performed. Alternatively, as shown in Figure 3, the HYBRIDIZATION SYSTEM manufactured by Nara Machinery Works can also be used. In other words, the modification process can be adopted with a fixed roller 21, a rotor 22 capable of rotating at a high speed, a circulation mechanism 2 4 and a discharge mechanism 2 5 for a primary sintered body 2 3, a blade 2 6, a stator 2 7, and a jacket 2 8 And using a method of supplying the primary sintered body 23 to the fixed drum 2] and the rotor 22, and applying a compressive force and a shearing force to the primary sintered body 23 to cause the speed difference between the fixed drum 21 and the rotor 2 2 get on. -28- (23) Although the conditions for the modification process vary depending on the equipment used, 'It cannot be said', but it is best to set the rate of decrease in the average particle size of the composite graphite material due to the treatment to be suppressed to Less than 20%. For example, when using a device with a rotating drum and internal components (Figure 2), it is best to use the following conditions, the peripheral speed difference between the rotating roller and the internal components: 5 ~ 50 m / s, two Distance between participants: 1 ~ 100m, processing time: 5 ~ 60 minutes. When using a device with a fixed drum and a high-speed rotor (Figure 3), it is best to use the following conditions, the speed difference between the fixed drum and the rotor: 10 ~ 100 m / s, processing time: 3 0 seconds to 5 minutes. In addition, as long as the effect of the present invention is not impaired, various conventional conductive materials, ion conductive materials, or Surfactants, metal compounds and binders. In the method of the present invention, the modified primary sintered body (referred to as a modified body in this case) is subjected to secondary sintering until the easily graphitizable carbon contained therein forms substantially graphitization. For example, the modified body is placed in a crucible, and secondary sintering is performed in a non-oxidizing environment. Using secondary sintering, graphitizable carbon can be graphitized, and graphite B and graphite C are produced. Although the temperature for the secondary sintering is not particularly limited, from the viewpoint of increasing the degree of graphitization, the higher the better. Preferably it is higher than 5 00 ° C, and higher than 2 500 ° C is more suitable. From the viewpoint of device heat resistance and prevention of sublimation of graphite, it is about 3300 ° C, and among them, 2800 to 3200t is the best. In the above-mentioned high-temperature environment, it is necessary to heat -29- (24) for 0.5 to 50 hours, and it is preferable to heat for 2 to 20 hours. Through the above processing, the graphite material of the present invention can be obtained, and by using the graphite material as a negative electrode material, a lithium ion secondary battery with a large discharge capacity can be produced. In the method of the present invention, after the primary sintering treatment, a disintegration treatment capable of disintegrating aggregates having a secondary aggregation or more is performed. During the secondary sintering of the present invention, no melt-glue or melt deformation occurs between the solids. Therefore, if the aforementioned composite body is provided that conforms to the shape of the final product, it is possible to simplify the pulverization and forming process for forming the desired shape after the secondary sintering. In addition, since the surface formed by this treatment can be kept low in crystallization, it is possible to sufficiently achieve the effects of the present invention. Therefore, as long as the disintegration after the primary sintering is performed after the primary sintering, any processing method is applicable. For example, it may be performed after secondary sintering. Instead of disintegrating the graphite constituting graphite A, it is only necessary to disintegrate the secondary agglomerate larger than the particle diameter of the required composite graphite material. According to the method of the present invention, R 値 in the Raman spectrum can be increased without changing the states of d 0 02 and Lc in the X-ray wide-angle diffraction method. The obtained composite graphite material has a core (formed from highly crystalline graphite A) and a coating layer (formed from graphite B having lower crystallinity than graphite A), and forms crystallinity on the surface of the graphite B site Lowest graphite C. Since graphite A and graphite B are both graphite materials, they can form a strong and tight bond at the connection interface. Particularly in a state where a plurality of graphite A granules are covered with graphite B, graphite A and graphite B have extremely high tight bonding due to the fixing effect. (Furthermore, graphite C is formed by the modification of part of graphite B, so the three can be integrated. Therefore, because graphite A, -30- (25) (25) 587350, graphite B and graphite C are not easy to peel off, and It can take into account the large discharge capacity originally possessed by graphite A and the high initial charge and discharge efficiency originally possessed by graphite B, so it is very suitable as a negative electrode material for lithium ion secondary batteries. Although the R 値 of the composite graphite material of the present invention is less than R 値 of traditional technology, but it has excellent initial charge and discharge efficiency. Although its structure is not easy to distinguish ', it can be achieved by new technology of forming graphitization by applying mechanical properties only to the outer surface of easily graphitizable carbon In the present invention, a negative electrode material containing any of the above-mentioned composite graphite materials is provided. (The composite graphite material of the present invention can utilize its characteristics to have uses other than the negative electrode. For example, it can be used as a fuel cell separator A conductive material or refractory graphite, etc., but it is most suitable for use as the negative electrode material of the above lithium ion secondary battery ^). In other words, the basic conditions of the negative electrode material of the present invention are Contains the above-mentioned composite graphite material. Therefore, the composite graphite material of the present invention itself is also the negative electrode material of the present invention. In addition, the negative electrode mixture obtained by mixing the composite graphite material of the present invention with a binder, and further comprising a solvent The negative electrode mixture paste and the member obtained by applying the negative electrode mixture paste to a polymer material belong to the scope of the negative electrode material of the present invention. Next, for the negative electrode of a bond ion secondary battery using the composite graphite material of the present invention as the negative electrode material, And the lithium ion secondary battery will be described. ≪ Negative electrode for lithium ion secondary battery > -31-(26) This case provides a method of using a composite graphite material containing any of the present invention as a lithium ion secondary battery. Invention of the negative electrode material. The negative electrode of the present invention is obtained by curing and / or shaping the above-mentioned negative electrode material of the present invention. Although the shape of the negative electrode is generally manufactured by molding, as long as the performance of graphite is fully utilized, , And give the powder extremely high plasticity, and then obtain a chemically and electrically stable negative electrode, any There are no particular restrictions on the methods used. In the manufacturing process of the negative electrode, [the negative electrode mixture / i can be used by adding a binder in the composite graphite material, and the negative electrode mixture is preferably a chemical stabilizer for the electrolyte and the electrolyte solvent. Those with good electrical and chemical stability j. For example, fluorine-based resins such as polyvinylidene chloride and tetrachloroethylene polymers; polyethylene, polyvinyl chloride, styrene-butadiene rubber; and carboxyl Methylcellulose, etc. Of course, the above are used together. The amount of binder used is usually about 1 to 20% of the mass of the negative electrode mixture. The negative electrode mixture is specifically classified. After the composite graphite material is adjusted to an appropriate particle size, it is mixed with a binder to prepare a negative electrode mixture. Generally, the negative electrode mixture can be applied to one or both sides of a polymer. A common solvent can be used for coating. After the negative electrode mixture is dissolved in the solvent to form a paste, the negative electrode mixture can be evenly and firmly adhered to the polymer body by simply coating it on the polymer and drying it. negative electrode. The aforementioned paste can be prepared by stirring with various mixers. For example, the composite graphite material of the present invention and fluorine-based resin powder such as tetrachloroethylene polymer can be mixed in a solvent such as isopropyl alcohol. -32- (27) (27) 587350 Then, a negative electrode mixture layer is formed after coating. Alternatively, the composite graphite material of the present invention, a fluorine-based resin powder such as polyvinylidene chloride, or a water-soluble binder such as carboxymethyl cellulose may be used with n-methylpyrrolidone, dimethylformamide, or After a solvent such as water and alcohol is mixed to form a suspension, a coating portion is applied to form a negative electrode mixture layer. When the negative electrode mixture obtained by mixing the composite graphite material of the present invention with a binder is applied to a polymer, the thickness of the negative electrode mixture is preferably 100-300 μm. If pressing and the like such as pressing and pressing are performed after the negative electrode mixture is formed, the adhesion strength between the negative electrode mixture layer and the polymer can be further increased. In the lithium ion secondary battery of the present invention, the shape of the polymer used for the negative electrode is not particularly limited, and a foil shape or a mesh shape such as a mesh or an expanded metal may be used. The polyelectric material can use copper, stainless steel, nickel and other metals. When forming a foil, the thickness of the polymer is preferably 5 to 20 μηι. In the present invention, there is further provided a lithium ion secondary battery using any of the foregoing negative electrodes. < Lithium-ion secondary battery > Generally, the main battery structure of a lithium-ion secondary battery is a negative electrode, a positive electrode, and a nonaqueous electrolyte. The positive and negative electrodes serve as lithium ion carriers, respectively. In the battery structure, lithium ions will penetrate into the negative electrode during charging, and will be released from the negative electrode during discharging. The lithium ion secondary battery of the present invention is not limited to a negative electrode made of -33- (28) (28) 587350, except that the negative electrode is composed of a negative electrode material containing the composite graphite material of the present invention. As the other constituent elements, a general lithium-ion secondary battery may be used. As the material of the positive electrode (positive electrode active material), it is preferable to select a material that can infiltrate / extract a considerable amount of lithium ions. For example, the above-mentioned positive electrode active material may be a complex thionide of lithium and a transition metal, or a complex oxide of lithium and a transition metal. A composite oxide of lithium and a transition metal (or a lithium metal-containing transition metal oxide) is preferably formed by solid-melting lithium with two or more transition metals. Specifically, for example, L i Μ (1)]. X Μ (2) X Ο 2 (in the chemical formula: 0 SXS 1, M (1), M (2) is formed of at least one transition metal) or LiM ( l) 2 · υM (2) γ〇4 (in the chemical formula: 0SYS1, M (]), M (2) is formed of at least one transition metal). In the above description, the transition metal represented by M may be metals such as C0, Ni, Mn, Cr, Ti, V, Fe, Zn, Al, In, and Sn. The lithium-containing transition metal oxides, for example, may use Li, transition metal oxides, or salts as starting materials, and may be mixed according to the combination of starting materials. 0 0 ° C ~] 〇0 0 ° C is obtained by sintering. The starting materials are not limited to oxides or salts, as long as they can be synthesized from hydroxides. In the present invention, the positive electrode active material may be used singly or in combination of two or more kinds. For example, a carbonate such as lithium carbonate may be added to the positive electrode. When a positive electrode is formed from the above-mentioned positive electrode material, for example, a positive electrode -34- (29) mixture formed of a positive electrode material and a binding agent and a conductive agent that imparts conductivity to the electrode can be applied to both surfaces of a polymer to form a positive electrode mixture. Floor. The binding agent may be any of those listed in the production of the negative electrode. The conductive agent can be carbon material, graphite or carbon black. The shape of the polymer is not particularly limited, and a foil shape or a mesh shape such as a mesh or an expanded metal may be used. For example, the polymer may be an aluminum foil, a stainless steel foil, a nickel foil, or the like. Its thickness is preferably i 0 to 40 μη1. The manufacturing method of the positive electrode is the same as that of the negative electrode. First, the positive electrode mixture is dissolved in a solvent to form a paste, and then the paste-like positive electrode mixture is applied to a polymer, and then the positive electrode mixture layer can be formed by drying. Similarly, the positive electrode mixture layer is formed. Thereafter, the positive electrode mixture layer can be evenly and firmly adhered to the polymer by pressing such as pressing. In the present invention, in the process of forming the above-mentioned negative electrode and positive electrode, various additives such as a conventionally used conductive agent or a binding agent may be appropriately added. The electrolyte used in the present invention may be an organic electrolyte formed of a solvent and an electrolyte salt, or a polymer electrolyte formed of a polymer and an electrolyte salt. For electrolyte salts, such as LiPF6, LiBF4,

LiAsF6, LiC104, LiB (C6H5), LiC], LiBr,

LiCF3S03, LiCH3, S〇3, LiN (CF3S〇2) 2.

LiN (CF3SO2) 3, LiN (CF3CH2〇S〇2) 2,

LiN (CF3CF2OSO2) 2 > LiN (HCF2CF2CH2OSO2) 2 '

LiN ((CF3) 2CHOSO2), LiB [C6H3 (CF3) 2] 4,

LiA] Cl4, LiSiF6, etc. Among them, LiPF6 and LiBF4 are most suitable because of their good oxidation stability5. The concentration of the electrolyte salt in the organic electrolyte is preferably from 0.5 to 5 mol / L rather than -35 · (30) (30) 587350, among which 0.5 to 3.0 mol / L is more suitable. Solvents for organic electrolytes include ethylene carbonate; propylene carbonate; dimethyl carbonate; diethyl carbonate; ethyl methyl carbonate; 1, 1 or 2; dimethoxyethane; 1 , 2-ethylene glycol ether, tetrahydrofuran; C 6 Η] 2 〇 (2-Methy] tetrahydr 〇pyra η); C 4 H 6 〇2 (7-

Butyrola clone); C3H6O2 (1,3-Dioxolane); C 4 H 6 〇3 (Propylene Carbonate); anisole; diethyl ether; cyclobutane; C8H] 8〇4S2 (Methylsulfona)); ethidium; Propionic acid diet, dimethyl boric acid; Si (OCH3) 4 (Tetramethyl Orthosilicate); nitromethane; dimethylformamide; N-methylpyrrolidone; ethyl acetate; trimethyl n-formate; Nitrobenzene; peroxyphenylhydrazone; tolyl bromide; tetrahydrophene; dimethylene; ethylene glycol; 3-Methy bu 2-OxazoIidone; aprotic organic solvents such as methyl sulfide. When a non-aqueous electrolyte is used as the polymer electrolyte, it contains a matrix polymer that is gelled by using a plasticizer (non-aqueous electrolyte). The matrix polymer can be used alone or in combination with ethers such as polyethylene oxide and its bridging body. Macromolecules; polyesters; polyacrylates; chlorine-based local molecules such as polyvinylidene fluoride and polyvinylidene-zirconium hi-propene co-coincidences. From the viewpoint of redox stability, the above-listed polymers are preferably fluorine-based polymers such as polyvinylidene fluoride and polyvinylidene fluoride-hexafluoropropylene copolymers.

As the electrolyte salt and the solvent constituting the plasticizer contained in the polymer electrolyte, any of the foregoing may be used. The concentration of the electrolyte (plasticizer) in the electrolytic solution is preferably from 0.1 to 5 m ο 1 / L, and the most preferably 0.5 to 2.0 m 0 1 / L -36- (31). The method for preparing the polymer electrolyte is not particularly limited. For example, in the p-d 'method, a matrix-forming polymer compound, a lithium salt, and a solvent may be mixed and then heated to decompose. Alternatively, a method in which a polymer compound, a cone salt and a solvent are dissolved in an appropriate amount of an organic solvent for mixing, and then the organic solvent for mixing is evaporated. Alternatively, a method in which a single molecule, a lithium salt, and a solvent are mixed and irradiated with ultraviolet rays, electron rays, or molecular rays to form a polymer. The addition ratio of the solvent in the 'polymer electrolyte is preferably from 0 to 90% by mass, and the most suitable is 30 to 80% by mass. When the above-mentioned addition ratio is 10 to 90% by mass, the electrical conductivity is high, the mechanical strength is high, and it is easy to form a thin film. In the lithium ion secondary battery of the present invention, a separator can also be used. The separator is not particularly limited. Fine porous membranes such as woven, non-woven, and synthetic resins can be used. Among them, a microporous membrane made of synthetic resin is most suitable. Among the microporous membranes made of synthetic resin, the thickness, membrane strength, and film friction surface of polyolefin-based microporous membranes are the best. Specifically, 'a fine porous film made of polyethylene and polypropylene, or a composite fine porous film of the two may be used. In the lithium ion secondary battery of the present invention, a polymer electrolyte can be used because of its high initial discharge rate. A lithium ion secondary battery using a polymer electrolyte is commonly referred to as a polymer I battery. Its structure can be composed of a negative electrode, a positive electrode, and a polymer electrolyte containing the composite graphite material of the present invention. For example, it can be made by stacking the negative electrode, polymer electrolyte -37- (32) (32) 587350, and the positive electrode in the order of being stored in the battery outer cover. In addition, a polymer electrolyte can also be provided outside the negative electrode and the positive electrode. In a polymer battery using the composite graphite material of the present invention as a negative electrode, propylene carbonate may be contained in the polymer electrolyte. In general, although propylene carbonate has an intense electrical decomposition reaction to graphite, it has extremely low decomposition reactivity to the composite graphite material of the present invention. In addition, the structure of the lithium ion secondary battery of the present invention may be any structure, and its shape and form are not particularly limited. Any of cylindrical, square, coin, and button types can be selected. In order to make a sealed non-aqueous electrolyte battery with higher safety, a means can be provided to detect an increase in the internal pressure of the battery and cut off the current when an abnormality such as overcharging occurs. When a polymer battery is manufactured using a polymer electrolyte, a structure in which a stacked film is enclosed may be adopted. Examples Next, examples of the present invention will be specifically described, but the present invention is not limited to the following examples. In the examples and comparative examples described later, the evaluation was performed by using a composite graphite material to produce a button-type primary battery for evaluation as shown in FIG. The battery is manufactured according to the technical idea of the present case and according to a general manufacturing method. In this evaluation battery, the working electrode refers to the negative electrode 'and the counter electrode corresponds to the positive electrode. < Preparation of negative electrode mixture paste > Corresponding to 90% by mass of the composite graphite material, poly-38- (33) (33) 587350 vinylidene fluoride was used as a binding agent, and N-methyl was used as a binder. The pyrrolidone was mixed as a solvent, followed by stirring at 2000 RPM for 30 minutes using an emulsifying mixing device, and then preparing an organic solvent-based negative electrode mixture paste. < Production of negative electrode > The above negative electrode mixture paste was first coated on a copper foil (polyelectric material) to a uniform thickness', and then heated to 90 ° C in a vacuum environment to evaporate the solvent and dry. Next, the negative electrode mixture coated on the copper foil is pressed by a roller press, and punched together with the copper foil to form a cylindrical shape having a diameter of 15.5 mm, and a copper foil (polyelectric body) that is closely adhered to the copper foil can be produced. 7b) of the negative electrode mixture layer (negative electrode 2). < Production of positive electrode > After pressing a lithium metal foil onto a nickel mesh foil, punching it into a cylindrical shape having a diameter of 15 mm, a polymer body formed of the nickel mesh foil 7 a, And a positive electrode 4 formed of a lithium metal foil tightly adhered to the electric body. < Electrolyte > Li PF 6 was dissolved in a mixed solvent composed of 3 3 v 〇]% of ethylene carbonate fingers and 67 v 〇]% of ethyl methyl carbonate to a concentration of 1 mol / dm3 Then, a non-aqueous electrolyte was prepared. The prepared non-aqueous electrolytic solution was impregnated into a polypropylene porous body to form a separator 5 impregnated with the electrolytic solution. < Production of evaluation battery > The evaluation battery was fabricated as a button-39- (34) 587350 secondary battery having a structure shown in FIG. 1. First, a separator 5 impregnated with an electrolytic solution is placed between the negative electrode 2 closely adhered to the polymer 7 b and the positive electrode 4 tightly adhered to the polymer 7 a to form a sandwich and laminate. Next, the side of the negative electrode collector 7b is placed in the outer cup 1, and the side of the positive electrode collector 7a is placed in the outer tank 3. Then, the outer cup] and the outer tank 3 are assembled. At this time, the insulating gasket 6 is sandwiched between the peripheral portions of the outer cup 1 and the outer tank 3, and the two outer edge portions are closed to form a hermetic seal. On the other hand, the evaluation battery prepared according to the above-mentioned method was subjected to the following charge-discharge experiment under an environment of 2 5 t. < Charge-discharge experiment > A quantitative current was charged at a current of 0.9 mA until the loop voltage reached 0 mV. Then, when the loop voltage reaches OmV, it switches to a fixed voltage and charges until the current 値 reaches 2 0 μA. After completing the above charging, pause] for 20 minutes. Next, perform a quantitative current discharge with a current of 0.9 mA until the loop voltage reaches 2.5 V. In order to obtain the charge and discharge amounts from the energized amount in the 1st cycle, the initial charge and discharge efficiency was calculated according to the following calculation formula. Initial charge and discharge efficiency (% (discharge amount in the first cycle) (charge amount in the first cycle) In the above experiment, charging refers to the process of lithium ions infiltrating into the composite graphite material, while discharging is the lithium ion from the composite graphite The material release process is -40- (35) 587350. It is equivalent to the characteristics of the battery, such as the discharge capacity (mAh / g) and initial charge and discharge efficiency (%) of the composite graphite material for measurement, as shown in Table 2. As shown in Table 2, the lithium ion secondary battery using the composite graphite material of the present invention as a negative electrode has a large discharge capacity and high initial charge and discharge efficiency. Next, the second cycle is the same as the first cycle After charging, use a current of 8 mA to perform a quantitative current discharge until the loop voltage reaches 2.5 V. At this time, based on the amount of discharge in the first cycle and the amount of discharge in the second cycle, use the following calculation formula to evaluate the rapid discharge Efficiency: Rapid discharge efficiency (%) (discharge amount in the second cycle) (discharge amount in the first cycle) In addition, the same conditions as in the first cycle were used to repeat the charge and discharge 20 times to perform experiments different from the previous experiments, and according to The following calculations are used to evaluate the cycle characteristics: · Cycle characteristics (%) (discharge amount at the 20th cycle) (charge amount at the 20th cycle) The above experiment was performed at the negative electrode electrode density]. 6 g / cm2 and []. (Embodiment 1) < Preparation of composite graphite material > -41-(36) Dissolving 80 mass units and containing about 40 mass% volatile content Coal tar (produced by Kawasaki Iron & Steel Co., Ltd. under the trade name PK-QL), and added with 50 mass units of natural graphite (produced by China-Vietnam Graphite Institute (Shares) under the trade name of BF 5 A, with an average particle size of 5 μ] η), and kneaded with a heating kneader. After the coarsely crushed attachments are obtained to form a disintegrated body, the primary adhered body is sintered in a non-oxidizing environment to obtain a primary sintered body having the following characteristics. The characteristics of the raw material and the primary sintered body, and whether or not they have been modified, are shown in Table I. In addition, the softening point (met Lefa) is 4 4 5 t. Once obtained The sintered body contains 50 mass units of primary sintered coal tar and 50 mass units of natural graphite. The above-mentioned primary sintered body was disintegrated by a vortex mill, and the average particle size was adjusted to be 20 pieces of particles. Put the pieces of particles into the modification processing device (MECHANOFUSION SYSTEM by HOSOKA WA MICRON GROUP) shown in Figure 2 (a) and (b), and apply mechanical energy. At this time, at Under the conditions that the peripheral speed of the rotating drum is 20 m / s, the processing time is 0 minutes, and the distance between the rotating drum and the internal components is 5 mm, compressive force and shearing force are repeatedly applied. The average of the primary sintered product after the modification treatment was 19 μm. Next, the primary sintered body treated with this plutonium was placed in a graphite crucible, and then filled with coke powder around the crucible, and heated for 5 small -42-(37) (37) 587350 at 3 000 t. Composite graphite material after secondary sintering. The obtained composite graphite material does not cause fusion and deformation, and can maintain the shape of its particles. Next, a battery for evaluation was produced using the aforementioned composite graphite material, and the battery characteristics were evaluated. The measured crystallinity and discharge capacity (mAh / g) equivalent to 1 g of the composite graphite material, initial charge and discharge efficiency (%), and rapid discharge efficiency (%) are shown in Table 2. As shown in Table 2, the composite graphite material according to the embodiment (an example of the present invention) has a higher discharge capacity than the material without the natural graphite and no modification treatment of Comparative Example 1, and has a higher initial charge and discharge efficiency. Furthermore, it has better initial charge and discharge efficiency, rapid discharge efficiency, and cycle characteristics than Comparative Example 2 containing natural graphite without modification. In addition, the surface of the composite graphite material of Example 1 subjected to the modification treatment can be formed with low crystallinity. (Example 2) < Preparation of graphite granules > Granulation was performed using natural graphite (HG3 0A produced by Sino-Vietnam Graphite Industry Co., Ltd., with an average diameter of 30 μm) to obtain a compact spherical shape or Spheroidal graphite granules. The graphite granules' had an average particle diameter of 20 μm and an aspect ratio of [.8]. D 〇〇2 = 0.3355 nm, L c = 86nm measured according to the X wide-angle acute method. The surface of the graphite granules formed was honed 'when the porosity (area ratio) in the particles was measured using a scanning electron microscope' was about 15% by volume. -43- (38) < Preparation of a complex of graphite and easily graphitizable carbon > Coal tar (manufactured by Kawasaki Iron & Steel Co., Ltd.) with a mass of 42 mass units and a content of about 40 mass% of volatile matter is produced. PK-QL) was dissolved in 58 mass units of medium tar to form a solution, and 1,000 mass units of this solution were prepared in advance. 100 mass units of the previously prepared graphite granules were put into the blender together with the above-mentioned solution of 1000 mass units, and the graphite granules were impregnated with the coal tar after stirring at 150 ° C for 30 minutes. In the solution, the medium tar as a solvent was then filtered off at the same temperature under a pressure of 0 mm H g. The prepared graphite granules were filled with an asphalt adherend in a steel container. In a sintering furnace equipped with a device capable of burning volatile gases, the adherend was subjected to primary sintering at 450 ° C for 20 minutes while flowing inert gas. This sintered body is in a state of being melt-adhered only between the graphitizable carbons on the surface of the graphite granules. An impact pulverizer was used to disintegrate the primary sintered body. The obtained primary sintered body had an average particle diameter of 22 μηι and an aspect ratio of 1.7. < Modification treatment > Next, the primary sintered body is put into a modification treatment device (a MECHANOFUSION SYSTEM by HOSOKAWA MICRON GROUP) shown in Figs. 2 (a) and (b), and mechanical properties are imparted. That is, under the conditions of a rotating drum peripheral speed of 20 m / s, a processing time of 30 minutes, and a distance of 5 mm between the rotating drum and the internal components, the compression-44-(39) (39) 587350 force and shear force are repeatedly applied. . The average example diameter of the primary sintered body after the modification treatment was 2 2 μηα, and the aspect ratio was 1 · 7. Compared with the average example diameter and aspect ratio before the modification treatment, there was no change. < Manufacturing of composite graphite material > Next, a graphite crucible was filled with the prepared modified body, and tar powder was filled around the graphite can. (: Heated for 5 hours to form graphitization 'and finally made a composite graphite material. After confirmation, the composite graphite material did not cause fusion adhesion and deformation, and could maintain the original particle shape. The average particle size of the composite graphite material was 2 2 μm, aspect ratio is 1.7, specific surface area is 0.5 m ** / g, bulk density is 1.02 g / cm .. Fe crystallinity d 〇〇2 measured by X wide-angle concealment method = 〇 · 3 3 5 7 nm, L c = 8 8 nm, R 値 measured by Raman spectroscopy is 0.08. Figure 4 shows a scan of the composite graphite material produced. Photograph of a type electron microscope. This composite graphite material was used to make the negative electrode of an evaluation battery, and the evaluation results of the battery characteristics are summarized in Table 2. (Examples 3 to 5) 00 mass units used in advance in Example 2 After adding 0.5 mass unit of anhydrous silicon oxide powder ("AEROSIL300" manufactured by Japan Aerosil Corporation, average particle size is 0 ·) to coal tar, it was sintered once, and changed. Easily graphitizable carbon after volatilization. For other conditions, use and The same conditions were used in Example 2 to produce a composite graphitized material. During the disintegration process after one sintering, -45- (40) (40) 587350 reduced the load of the pulverizer and easily formed disintegration. Various evaluations are performed on the graphite material, and the crystallinity and battery characteristics are summarized in Table 2. As shown in Table 2, the evaluation battery using the composite graphite material of Examples 2 to 5 has a theoretical capacity approaching that of graphite (3 72 mAh / g) has a large discharge capacity, and has a very high initial charge and discharge efficiency. Among them, Examples 3 to 5 in which anhydrous silicon oxide powder made by a gas phase method is added to easily graphitizable carbon are more excellent. The initial charge and discharge efficiency of the product has the effect of suppressing "lead-graphitizable carbon that is liable to be disintegrated after melt adhesion and easy peeling of the graphitizable carbon film". In addition, it also has excellent rapid discharge efficiency and cycle characteristics. Even in the state of high electrode density, it also has excellent rapid discharge efficiency and cycle characteristics. (Comparative Example 1) Except that natural graphite is not added to the easily graphitizable carbon as in Example 1, it is not insistent. Except for the modification treatment, the graphite material was produced under the same conditions as in the example. The graphite material produced will have a molten adhesion between the graphite materials after the second sintering, and it cannot maintain the disintegration after the first sintering. Therefore, it is necessary to disintegrate the graphite material after fusion and adjust its average particle size to 19 μη] to produce an evaluation battery. The evaluation results of the crystallinity and battery characteristics are shown in the table. As shown in Table 2. As shown in Table 2, Comparative Example 1 using a graphite material that does not contain natural graphite and has not been modified has a significantly reduced discharge capacity and initial charge-discharge efficiency. -46-(41) (41 587350 (Comparative Example 2) A graphite material was produced in the same manner as in Example 1 except that the modification treatment in Example 1 was omitted. The obtained graphite material has a slight melting adhesion between the graphite materials after the second sintering, and cannot maintain the shape obtained after the first sintering. Therefore, it is necessary to disintegrate the graphite material after melting and adjust the average particle diameter to 19 μm to prepare an evaluation battery. The results of evaluation of the crystallinity and battery characteristics are shown in Table 2. As shown in Table 2, Comparative Example 2 'without the modification treatment characteristic of the present invention did not form low crystallization on the graphite surface, and the initial charge and discharge efficiency was significantly reduced. (Comparative Example 3) Except that the secondary sintering temperature in Example 1 was changed to! Other than 300 ′, graphite material was produced in the same manner as in Example 1. The produced graphite material is equivalent to a conventional product, and natural graphite is contained in a non-graphite material. In addition, no fusion adhesion was observed in the produced material, and the shape after pulverization was maintained. An evaluation battery was produced in the same manner as in Example 1 with this graphite material. Table 2 shows the results of S-evaluation of crystallinity and battery characteristics. As shown in Table 2, in Comparative Example 3 where the secondary sintering temperature was lowered and the graphitizable carbon was not sufficiently graphitized, the crystallinity of the material was low, and the discharge amount was also significantly reduced. -47- (42) (42) 587350 (Comparative Example 4) The conditions for applying the modification treatment of Example 1 'Directly to natural graphite (produced by China-Vietnam Graphite Industry Institute (stock)', product name is BF] 0A, the average particle size is 10 μηι) for modification. No melt adhesion and deformation were found in the graphite after the modification treatment, and the shape after pulverization was maintained. Its average particle diameter is 9 μη: ι. Next, the same graphite as in Example 1 was produced using this natural graphite, and its battery characteristics were evaluated. The crystallinity and battery characteristics are shown in Table 2. As shown in Table 2, inevitable Comparative Example 4 ', which attempts to directly modify the natural graphite to reduce the surface crystallinity, has a low initial charge and discharge efficiency. However, its rapid discharge efficiency and cycle characteristics are not good. Increasing the electrode density will orient the graphite particles, causing the above characteristics to deteriorate again. (Comparative Example 5) A battery for evaluation was produced by using natural graphite (produced by China Vietnam Graphite Industry Co., Ltd. under the trade name of B F] 0 A and average particle size of 100 μm). The manufacturing method and evaluation method of the evaluation battery were the same as those in the first embodiment. The evaluation results of the crystallinity and battery characteristics are shown in Table 2. As shown in Table 2, Comparative Example 5 in which natural graphite was used alone had a large discharge M, but had poor initial charge and discharge efficiency, rapid discharge efficiency, and cycle characteristics. If the electrode density is increased, the above characteristics will be significantly reduced. -48- (43) (43) 587350 (Comparative Example 6) A graphite material was produced in the same manner as in Example 2 except that the modification treatment in Example 2 was omitted. The evaluation results of the crystallinity and battery characteristics are shown in Table 2. As shown in Table 2, Comparative Example 6, which was made of a graphite material without modification treatment, had low initial charge and discharge efficiency. In addition, compared with Comparative Example 6, it can be seen that R 値 in Example 2 is larger, and low crystallinity can be selectively formed on the surface of the graphite material.

-49- 587350 1 谳 Note /-~ s ψ ^ / -N / ^ N ψ (Modification treatment 1 1_ &sentence; UJ, physical properties of easily graphitizable carbon after kneading once sintering 1 \ 〇C \ 〇 \ 〇〇ο < η 〇 \ (N ON Ό C \ Ό CN 〇〇κη 〇 \ Volatility (%) (N inch · (N 〇 〇〇〇rn ΓΝ1 inch 00 〇νν (N ' sT 〇〇 (N vd microparticle content (%) 〇〇 ^ Γί 〇 〇 〇 〇〇ο ο kind of fumed silica fumed silica fumed silica fumed silica graphite raw material of graphite B (easy graphitizable carbon) coal tar coal Tar coal tar coal tar coal tar coal tar coal tar coal tar coal tar graphite A content (%) § § § 00 shape shape flaky granules granules granules granules granules scales scales scales scales scales scales Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 ^ 鹚 堤 _ ^ ::: 衾 3 (1 -50- 587350 s .1 1 1 ili3 / s / ^ N Battery characteristics Γ r-1 I oo w cycle characteristics (%) (NC \ m G \ G \ ^ T) oc VO OO ν〇VO C \ \ 〇OO rapid discharge rate (%) Ό 〇〇5; rsi m Os (N Cs r- g § oo Initial charge and discharge rate (%) (N 〇m oo oc m oc Discharge (mAh / g) 360 m ^ sO mv〇m Ό 354 360 292 Ό VO m VO mm Electrode density: 1.6 g / c .m3 cycle characteristics (%) m CN v〇ON On oo oo oo σ > 00 rn OO On (N rapid discharge rate (%) g ^ T) c \ customer ON m oc oc oc oo rn OC VO g initial charge and discharge Rate (%) m 〇 \ tn Ch to o oc oo 〇 \ oc \ 〇oo ON 00 Discharge volume (mAh / g) 360 to 366 < nmmm 355 CN (N 368 369 to VO < & PI Raman spectrometry R 値 0.12 0.08 0.06 0.09 0.13 0.03 0.04 0.32 0.02 0.02 0.04 X-ray wide-angle diffraction (_) oo oo ON OO to 00 JO vo oo m to On OO rsi 〇0.3358 0.3357 0.3357 0.3357 0.3358 0.3360 0.3358 0.3367 0.3356 0.3356 0.3357 Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 OOP- ^ sin 壊 csii Yunzhen ^ iis # _ ^ si-s let sn_ (e

-51 · (46) (46) 587350 [Industrial applicability] The composite graphite material of the present invention can be applied to a negative electrode and a negative electrode material. A lithium ion secondary battery using this negative electrode material can sufficiently achieve both of the characteristics that run counter to high initial charge and discharge efficiency and large discharge capacity. In addition, according to the method of the present invention, it is possible to suppress the phenomenon of fusion adhesion and the like in the graphitization process, and to produce the aforementioned composite graphite material with high productivity. Therefore, with the composite graphite material of the present invention, it is possible to satisfy the demand for higher density of battery energy in recent years. Furthermore, a device equipped with the negative electrode material, the negative electrode, and the lithium ion secondary battery of the present invention can effectively be miniaturized and achieve high performance, and can contribute to society. [Brief Description of the Drawings] Figure 1: A schematic cross-sectional view for explaining the structure of the evaluation battery used in the examples and comparative examples of this case. Figure 2: (a) is an action mechanism diagram illustrating a modification of a mechanical property used in the present case, and (b) is a schematic view of the structure of the device. Figure 3: Schematic diagram of a modified arm handling device for the mechanical properties used in this section. Figure 4: Scanning electron microscope image of a composite graphite material made according to Example 2 [Symbols] • 52- (47) 587350 1 Outer cup 2 Negative electrode 3 Outer can 4 Positive electrode 5 Separator 6 Insulation pad

7 a Polyelectric body 7b Polyelectric body 1 1 Rotate the drum 1 2 Internal components (internal screw) 1 3 Primary sintered body 14 Circulation mechanism 15 Discharge mechanism

2 1 Fixed roller 22 Rotor 23 Primary sintered body 24 Circulation mechanism 25 Discharge mechanism 2 6 Blade 2 7 Stator 2 8 Jacket • 53-

Claims (1)

(1) (1) 587350 Scope of claiming and claiming patents 1. A composite graphite material having a structure in which a stone & B on the outside of graphite A has lower crystallinity than the graphite A, and the At least a part of the outer surface of the graphite β is a graphite c having lower crystallinity than the graphite B. -The composite graphite material according to item 1 of the Shenyang patent scope, which has a skid made of the graphite B covering the graphite a and the graphite C covering the graphite B. 3. The composite graphite material according to the scope of the patent application, wherein the composite ballast material is a spherical or ellipsoidal granule. 4. The composite graphite material according to item 1 of the scope of the patent application, in which the above-mentioned composite stone material as a whole, the interplanar spacing (d㈣2) of the carbon mesh surface layer is below 0.33 6 5 ηΠ1, and the crystal axis The size (L0 is the ratio of the spectroscopy of 40nm or more) of 3 6 0 cm ·] peak 値 intensity (113 6 〇) relative square 々 15 8 0 cm. Peak 値 intensity (1) $ 8.。 (1136g / I15S.) Is 0.0 5 or more and 0.30 or less. 5 • The composite graphite material as described in the first item of the patent application, wherein the aforementioned graphite A is flaky graphite. 6 • The compound as the first item of the patent application Graphite materials, in which the above-mentioned graphite A-wrapped carbon mesh surface layer has a surface interval (dGQ2) of 0.3 35 Snm. 7 · As in the case of the composite graphite material in the first scope of the patent application, the above-mentioned graphite B Chu carbon The interplanar spacing (do. 2) of the mesh surface layer is 0.333 nm, which is 0 -54- (2) (2) 587350 8. A negative electrode material for lithium ion secondary batteries, which contains, for example, a patent application The composite graphite material according to any one of the items 1 to 7. 9. A negative electrode for a lithium ion secondary battery, Contains the composite graphite material as described in any one of the scope of claims 1 to 7. 10. A lithium ion secondary battery that contains the negative electrode as described in the scope of claims 9. Π. — A method for manufacturing a composite graphite material is used to produce graphite B which has a lower crystallinity than graphite A on the outside of graphite A, and at least a part of the outer surface of the graphite B is present. Compared with the graphite B, a composite graphite material having a structure with a lower crystalline part, the manufacturing method has: a process of attaching carbon having an easy graphitization property on the outside of the graphite; Carbon is substantially ungraphitized, and the first sintering process is performed on the adherend; the first sintered body is modified by applying mechanical energy in a manner that does not substantially crush; The modified body undergoes the second sintering process until the carbon with easy graphitization characteristics has been substantially graphitized.] 2. Compounding as in item 11 of the scope of patent application The manufacturing method of the ink material, wherein the foregoing graphite is flaky graphite. 13. The manufacturing method of the composite graphite material according to item 11 of the patent application scope, wherein the foregoing graphite is a carbon mesh surface layer with an inter-space (dG () 2) of -55- (3) (3) 587350 0..3 3 5 8nm or less.] 4 · As in the method of manufacturing a composite graphite material in the scope of patent application No. 11 'wherein the aforementioned carbon having easy graphitization characteristics is : At least one selected from the group consisting of tar, pitch, and mesophase. [5] The method for manufacturing a composite graphite material according to item 11 of the scope of patent application ', wherein the graphite is granulated before the aforementioned attachment process. 16. The method for manufacturing a composite graphite material according to item 11 of the scope of patent application (wherein the aforementioned attachment process is to use at least one method selected by melting, dissolving or dispersing the carbon which has easy graphitization characteristics into a liquid And then make it adhere to the graphite > I 7. As in the method of manufacturing a composite graphite material according to item 11 of the patent application, wherein the first sintering process described above makes the carbon having easy graphitization characteristics The remaining volatile component becomes 2.0% by mass or more and 20% by mass or less. 1 8 · The manufacturing method of the composite graphite material according to item 11 of the patent application scope, wherein after the aforementioned first sintering process, the secondary agglomeration is further increased. The process of disaggregating the disaggregated aggregates (disagg I omerate). -56-