JP5671110B2 - Negative electrode material for lithium ion secondary battery and method for producing the same, negative electrode for lithium ion secondary battery, and lithium ion secondary battery - Google Patents

Negative electrode material for lithium ion secondary battery and method for producing the same, negative electrode for lithium ion secondary battery, and lithium ion secondary battery Download PDF

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JP5671110B2
JP5671110B2 JP2013168574A JP2013168574A JP5671110B2 JP 5671110 B2 JP5671110 B2 JP 5671110B2 JP 2013168574 A JP2013168574 A JP 2013168574A JP 2013168574 A JP2013168574 A JP 2013168574A JP 5671110 B2 JP5671110 B2 JP 5671110B2
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間所　靖
靖 間所
酒井　稔
稔 酒井
長山　勝博
勝博 長山
洋典 森岡
洋典 森岡
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Description

本発明は、リチウムイオン二次電池用負極材料とその製造方法、ならびにその負極材料を用いたリチウムイオン二次電池用負極、およびその負極を用いたリチウムイオン二次電池に関し、特に放電容量が大きく、レート特性に優れるリチウムイオン二次電池、それに用いる負極ならびに負極材料とその製造方法に関する。   The present invention relates to a negative electrode material for a lithium ion secondary battery, a method for producing the same, a negative electrode for a lithium ion secondary battery using the negative electrode material, and a lithium ion secondary battery using the negative electrode, and particularly has a large discharge capacity. The present invention relates to a lithium ion secondary battery having excellent rate characteristics, a negative electrode used therefor, a negative electrode material, and a method for producing the same.

近年、電子機器の小型化あるいは高性能化に伴い、電池のさらなる高エネルギー密度化に対する要望はますます高まっている。特に、リチウムイオン二次電池は、他の二次電池に比べて高電圧化が可能であり、エネルギー密度を高められるため注目されている。リチウムイオン二次電池は、負極、正極および非水電解質を主たる構成要素とする。非水電解質から生じるリチウムイオンは放電過程および充電過程で負極と正極との間を移動し、二次電池となる。通常、リチウムイオン二次電池の負極材料には炭素材料が使用される。このような炭素材料として黒鉛が多く用いられている。   In recent years, with the miniaturization or higher performance of electronic devices, there has been an increasing demand for higher energy density of batteries. In particular, lithium ion secondary batteries are attracting attention because they are capable of higher voltages than other secondary batteries and can increase energy density. A lithium ion secondary battery has a negative electrode, a positive electrode, and a non-aqueous electrolyte as main components. Lithium ions generated from the non-aqueous electrolyte move between the negative electrode and the positive electrode during the discharge process and the charge process, forming a secondary battery. Usually, a carbon material is used as a negative electrode material of a lithium ion secondary battery. Graphite is often used as such a carbon material.

黒鉛はリチウムイオン二次電池の負極材料として高い放電容量と優れた電位平坦性を有するが、黒鉛のエッジ面と呼ばれる活性部位では、非水電解質の反応性が高く、エッジ面が多く露出している場合には、初回充放電ロスが増大する問題、すなわち、初回充放電効率が低下する問題がある。   Graphite has a high discharge capacity and excellent potential flatness as a negative electrode material for lithium ion secondary batteries. However, in the active site called the edge surface of graphite, the reactivity of the nonaqueous electrolyte is high and the edge surface is exposed a lot. If there is, there is a problem that the initial charge / discharge loss increases, that is, the initial charge / discharge efficiency decreases.

前記問題を解決するために、特許文献１には、芯材の炭素材料の結晶のエッジ部分の一部または全部を、被覆形成用炭素材料で被覆して、ほぼ球状ないし楕円体状とした炭素材料が提案されている。特許文献１では、芯材の炭素材料を何ら制約していないが、例えば、エッジ部分が非常に多い鱗片状天然黒鉛を用いた場合、エッジ部分を被覆形成用炭素材料で完全に被覆することは困難であり、充分な充放電ロスの低減は難しい。また、鱗片状黒鉛を用いた負極はプレスによる負極内粒子の配向が大きく、負極内でのリチウムイオンの拡散が阻害されるためレート特性が著しく低下する。   In order to solve the above-mentioned problem, Patent Document 1 discloses carbon that is formed into a substantially spherical or ellipsoidal shape by covering part or all of the edge portion of the crystal of the carbon material of the core material with the carbon material for coating formation. Materials have been proposed. In Patent Document 1, the carbon material of the core material is not restricted at all. However, for example, when scaly natural graphite having a very large edge portion is used, the edge portion is not completely covered with the carbon material for coating formation. It is difficult, and it is difficult to sufficiently reduce the charge / discharge loss. In addition, the negative electrode using scaly graphite has a large orientation of the particles in the negative electrode by pressing, and the diffusion of lithium ions in the negative electrode is inhibited, so that the rate characteristics are remarkably lowered.

一方、エッジ部分の少ないメソフェーズカーボン小球体の黒鉛化物は充放電ロスが元来小さく、被覆形成用炭素材料で被覆しても格別の充放電ロスの低減は認められない。また、エッジ部分の少ないメソフェーズカーボン小球体の黒鉛化物は球状ゆえに、負極内における粒子間接点が少なく、電子伝導性が不足するためレート特性（急速充放電効率）が劣る。確かに、炭素材料の被覆によってエッジ部分の表面が硬質化するのでレート特性が若干向上するが、依然として実用レベルに及ばず、むしろ黒鉛化物の粉体のタップ密度（充填密度）の低下を招来する。タップ密度の低下は負極内の黒鉛化物の充填度合いの低下につながるので好ましくない。
このように、基材の黒鉛に対する炭素材料の被覆による改質は、基材を最適な状態に調整しないと、期待する特性（放電容量、初期充放電効率、レート特性）を充分に向上させることができないばかりか、場合によっては、逆に低下させる恐れすらある。 On the other hand, the mesophase carbon spherulite graphitized material having a small edge portion originally has a small charge / discharge loss, and even if it is coated with a coating-forming carbon material, no particular reduction in charge / discharge loss is observed. Further, since the graphitized mesophase carbon microspheres with few edge portions are spherical, there are few particle indirect points in the negative electrode, and the electron conductivity is insufficient, resulting in poor rate characteristics (rapid charge / discharge efficiency). Certainly, the surface characteristics of the edge portion are hardened by the coating of the carbon material, so that the rate characteristic is slightly improved, but it still does not reach the practical level, but rather the tap density (packing density) of the graphitized powder is reduced. . A decrease in tap density is not preferable because it leads to a decrease in the degree of filling of the graphitized material in the negative electrode.
As described above, the modification of the base material by covering the graphite with the carbon material sufficiently improves the expected characteristics (discharge capacity, initial charge / discharge efficiency, rate characteristics) unless the base material is adjusted to an optimum state. In addition to being unable to do so, in some cases there is even a risk of lowering.

国際公開ＷＯ９７／１８１６０号公報International Publication No. WO 97/18160

本発明は、前記のような状況に鑑みてなされたものであり、リチウムイオン二次電池用負極材料として、高い放電容量および高い初回充放電効率が得られ、さらに優れたレート性が得られる負極材料を提供することを目的とする。また、そのような負極材料の製造方法と、その負極材料を用いてなるリチウムイオン二次電池用負極およびその二次電池用負極を用いたリチウムイオン二次電池を提供することが目的である。   The present invention has been made in view of the above situation, and as a negative electrode material for a lithium ion secondary battery, a high discharge capacity and a high initial charge / discharge efficiency can be obtained, and a further excellent rate performance can be obtained. The purpose is to provide material. Another object of the present invention is to provide a method for producing such a negative electrode material, a negative electrode for a lithium ion secondary battery using the negative electrode material, and a lithium ion secondary battery using the negative electrode for the secondary battery.

前記目的を達成するための本発明は以下の通りである。
すなわち、本発明は、メソフェーズカーボン小球体の黒鉛化物を基材とし、前記基材の表面の少なくとも一部に、前記基材の表面よりも結晶性の低い炭素質物の付着物を有するリチウムイオン二次電池用負極材料であって、前記黒鉛化物がメソフェーズカーボン小球体を粉砕した後、黒鉛化して得た黒鉛化物であって、前記基材のＸ線回折による炭素網面層の格子面間隔ｄ００２が０．３３６５ｎｍ以下で、波長５１４．５ｎｍのアルゴンレーザーを用いたラマンスペクトルにおける１３６０ｃｍ−１のピーク強度と１５８０ｃｍ−１のピーク強度との強度比（ＲＡ）が０．０５〜０．３であり、かつ、前記負極材料の前記ラマンスペクトルにおける１３６０ｃｍ−１のピーク強度と１５８０ｃｍ−１のピーク強度との強度比（ＲＢ）が０．３以上であって、ＲＡ＜ＲＢであり、前記結晶性の低い炭素質物の付着物が、炭素繊維を含有することを特徴とするリチウムイオン二次電池用負極材料である。 To achieve the above object, the present invention is as follows.
That is, the present invention provides a lithium ion secondary battery having a mesophase carbon microsphere graphitized material as a base material, and having a carbonaceous material deposit having lower crystallinity than the surface of the base material on at least a part of the surface of the base material. A negative electrode material for a secondary battery, wherein the graphitized product is obtained by pulverizing mesophase carbon spherules and then graphitized, and the lattice spacing d of the carbon network layer by X-ray diffraction of the substrate 002 below 0.3365 nm, the intensity ratio of the peak intensity of the peak intensity and 1580 cm -1 in 1360 cm -1 in the Raman spectrum using argon laser having a wavelength of 514.5 nm (R a) is 0.05 to 0.3 , and the and the intensity ratio of the peak intensity of the peak intensity and 1580 cm -1 in 1360 cm -1 in the Raman spectrum of the negative electrode material (R B) A 0.3 or more, a R A <R B, fouling of the low crystallinity carbonaceous material, a negative electrode material for a lithium ion secondary battery, characterized by containing carbon fibers.

本発明のリチウムイオン二次電池用負極材料は、前記した結晶性の低い炭素質物の付着物が、複数の炭素質物からなるか、または、黒鉛化物を含有することが好ましい。   In the negative electrode material for a lithium ion secondary battery of the present invention, it is preferable that the carbonaceous matter deposit having low crystallinity is composed of a plurality of carbonaceous materials or contains a graphitized material.

また、本発明は、メソフェーズカーボン小球体を粉砕する粉砕工程と、前記粉砕工程で得られたメソフェーズカーボン小球体の粉砕品を加熱する黒鉛化工程と、前記黒鉛化工程で得られたメソフェーズカーボン小球体の黒鉛化物の表面の少なくとも一部に炭素質材料および炭素繊維を付着させる付着工程と、前記付着工程で得られた炭素質材料が付着したメソフェーズカーボン小球体の黒鉛化物を加熱し、前記炭素質材料を炭化する炭化工程を有することを特徴とする、上記いずれかのリチウムイオン二次電池用負極材料を製造する、リチウムイオン二次電池用負極材料の製造方法である。   The present invention also includes a pulverization step for pulverizing mesophase carbon spherules, a graphitization step for heating a pulverized product of mesophase carbon spherules obtained in the pulverization step, and a mesophase carbon small sphere obtained in the graphitization step. A carbonaceous material and carbon fiber adhered to at least a part of the surface of the spherical graphitized material, and the mesophase carbon microsphere graphitized material to which the carbonaceous material obtained in the adhesion step is adhered is heated, and the carbon It has the carbonization process which carbonizes a porous material, It is the manufacturing method of the negative electrode material for lithium ion secondary batteries which manufactures any one said negative electrode material for lithium ion secondary batteries.

また、本発明は、前記いずれかのリチウムイオン二次電池用負極材料を用いることを特徴とするリチウムイオン二次電池用負極である。   Moreover, this invention uses the said negative electrode material for lithium ion secondary batteries, The negative electrode for lithium ion secondary batteries characterized by the above-mentioned.

また、本発明は、前記のリチウムイオン二次電池用負極を用いることを特徴とするリチウムイオン二次電池である。   The present invention also provides a lithium ion secondary battery using the negative electrode for a lithium ion secondary battery.

本発明は、高い放電容量、初回充放電効率およびレート特性を有するリチウムイオン二次電池用負極材料を提供する。そのため、本発明の負極材料を用いてなるリチウムイオン二次電池は、近年の電池の高エネルギー密度化に対する要望を満たし、搭載する機器の小型化および高性能化に有効である。   The present invention provides a negative electrode material for a lithium ion secondary battery having high discharge capacity, initial charge / discharge efficiency, and rate characteristics. Therefore, the lithium ion secondary battery using the negative electrode material of the present invention satisfies the recent demand for higher energy density of the battery, and is effective in reducing the size and performance of the mounted device.

本発明の負極材料、負極の電池特性を評価するための評価電池の概略断面図である。It is a schematic sectional drawing of the evaluation battery for evaluating the battery characteristic of the negative electrode material of this invention, and a negative electrode. 本発明の負極材料の一例（参考例１）の外観を示す走査型電子顕微鏡写真である。It is a scanning electron micrograph which shows the external appearance of an example (reference example 1) of the negative electrode material of this invention. 比較例２の負極材料の外観を示す走査型電子顕微鏡写真である。4 is a scanning electron micrograph showing the appearance of a negative electrode material of Comparative Example 2.

以下、本発明をより具体的に説明する。
本発明のリチウムイオン二次電池用負極材料は、メソフェーズカーボン小球体の粉砕品の黒鉛化物を基材とし、前記基材の表面の少なくとも一部、好ましくは前記基材のエッジ面に、前記基材の表面よりも結晶性の低い炭素質物が付着した負極材料である。
以下、基材、付着物、負極材料、付着方法、負極、正極、非水電解質、セパレータ、リチウムイオン二次電池の順に説明する。 Hereinafter, the present invention will be described more specifically.
The negative electrode material for a lithium ion secondary battery of the present invention is based on a graphitized product of pulverized mesophase carbon spherules, and at least a part of the surface of the base material, preferably on the edge surface of the base material. It is a negative electrode material to which a carbonaceous material having lower crystallinity than the surface of the material is attached.
Hereinafter, the substrate, the deposit, the negative electrode material, the deposition method, the negative electrode, the positive electrode, the nonaqueous electrolyte, the separator, and the lithium ion secondary battery will be described in this order.

〔基材〕
本発明の負極材料の基材として用いられる黒鉛化物は、メソフェーズカーボン小球体（以後、単に小球体とも記す）を粉砕して得た粉砕品を黒鉛化してなる黒鉛化物である。前記黒鉛化物は、通常、表面の少なくとも一部に、黒鉛化物の内部に比べて結晶性の低い、原料ピッチ等に由来する炭素質の極薄層を有する二層構造体である。 〔Base material〕
The graphitized material used as the base material of the negative electrode material of the present invention is a graphitized material obtained by graphitizing a pulverized product obtained by pulverizing mesophase carbon small spheres (hereinafter also simply referred to as small spheres). The graphitized material is usually a two-layer structure having a carbonaceous ultrathin layer derived from a raw material pitch or the like having low crystallinity compared to the inside of the graphitized material on at least a part of the surface.

メソフェーズカーボン小球体は、石油系または石炭系のピッチ類を３５０〜４５０℃程度の温度で加熱した際に、ピッチマトリックス中に生成する粒径が数μｍ〜数十μｍの光学的異方性小球体である。前記小球体は、ピッチマトリックスからベンゼン、トルエン、キノリン、タール中油、タール重油などの溶剤を用いて抽出分離される。   Mesophase carbon microspheres have small optical anisotropy with a particle size of several μm to several tens of μm generated in a pitch matrix when petroleum or coal pitches are heated at a temperature of about 350 to 450 ° C. It is a sphere. The small spheres are extracted and separated from the pitch matrix using a solvent such as benzene, toluene, quinoline, tar middle oil, or tar heavy oil.

分離されたメソフェーズカーボン小球体を３５０℃以上、好ましくは３５０〜９００℃の温度で焼成した後、分級によって粗粒および塊状物を除去し、粉砕して粒度分布を調整した小球体の焼成生成物を得る。
前記焼成はロータリーキルンなどを用いて、不活性雰囲気中で行うことができる。前記焼成時に前記小球体の表面に付着していた微量のピッチ等が炭化される。 After firing the separated mesophase carbon microspheres at a temperature of 350 ° C. or higher, preferably 350 to 900 ° C., the coarse particles and the lump are removed by classification and pulverized to adjust the particle size distribution. Get.
The firing can be performed in an inert atmosphere using a rotary kiln or the like. A small amount of pitch or the like attached to the surface of the small spheres during the firing is carbonized.

前記分級は篩、風力分級等の一般に工業的に行われている方法で実施される。例えば、２００メッシュ（篩目７５μｍ）の篩を用いて目標とする最大粒子径未満に調整される。粒子径調整後、付着工程に供される小球体の平均粒子径は２〜１００μｍ、特に５〜５０μｍであることが好ましい。粒子径調整後の前記小球体の平均粒子径が前記範囲内であれば、表面積の増大による初回充放電効率の低下の問題が解消され、かつ負極合剤を調製後、集電体に塗布する際の電極塗装性が良好である。
なお、焼成生成物を粉砕、分級して粒度調整した後、黒鉛化してもよく、粉砕後の焼成生成物の分級による粗粒および塊状物、微粉の除去を前記焼成生成物の黒鉛化後に行うこともできる。
粒子径調整後の前記小球体の窒素ガス吸着ＢＥＴ法による比表面積は５ｍ２／ｇ以下、特に１ｍ２／ｇ以下であることが好ましい。 The classification is performed by a generally industrially performed method such as sieving or air classification. For example, the particle size is adjusted to be less than the target maximum particle size using a 200-mesh (sieving mesh 75 μm) sieve. After the particle size adjustment, the average particle size of the small spheres used in the adhesion step is preferably 2 to 100 μm, particularly preferably 5 to 50 μm. If the average particle size of the small spheres after the particle size adjustment is within the above range, the problem of decrease in the initial charge / discharge efficiency due to the increase in surface area is solved, and the negative electrode mixture is prepared and then applied to the current collector. The electrode paintability at the time is good.
The baked product may be pulverized and classified to adjust the particle size and then graphitized, and coarse particles, aggregates, and fine powders may be removed after the baked product is graphitized by classification of the baked product. You can also.
The specific surface area of the small spheres after the particle diameter adjustment by nitrogen gas adsorption BET method is preferably 5 m 2 / g or less, particularly preferably 1 m 2 / g or less.

前記小球体の粉砕は粒度分布の最適化によるリチウムイオン二次電池用負極材料としての特性向上などに有効な不可欠な工程である。
粉砕手段は特に限定されないが、比較的精密な粒度制御が可能なジェット粉砕などが好適である。前記粉砕条件も格別限定されない。なお、小球体の平均粒子径が１００μｍ以下、好ましくは５０μｍ以下、さらに好ましくは３〜２０μｍになるように条件設定する。
小球体の黒鉛化前に粉砕せずに、小球体を黒鉛化して得た黒鉛化物の粉砕品を、リチウムイオン二次電池用負極材料として用いた場合には初回充放電効率の点で劣るので、小球体の黒鉛化前に粉砕することが重要である。これは、黒鉛化後の粉砕品にはエッジ面が多く存在していることに拠るものと推定される。 The pulverization of the small spheres is an indispensable process effective for improving characteristics as a negative electrode material for a lithium ion secondary battery by optimizing the particle size distribution.
The pulverizing means is not particularly limited, but jet pulverization capable of relatively precise particle size control is suitable. The grinding conditions are not particularly limited. The conditions are set so that the average particle size of the small spheres is 100 μm or less, preferably 50 μm or less, and more preferably 3 to 20 μm.
When a pulverized product of graphitized material obtained by graphitizing a small sphere without graphitizing the small sphere is used as a negative electrode material for a lithium ion secondary battery, it is inferior in terms of initial charge / discharge efficiency. It is important to pulverize the small spheres before graphitization. This is presumed to be due to the presence of many edge surfaces in the pulverized product after graphitization.

粒子径調整後の前記メソフェーズカーボン小球体を、さらに２０００℃以上、好ましくは２５００℃以上の温度で加熱することにより、結晶性が高いメソフェーズカーボン小球体（黒鉛質）の表面に、前記表面に付着していたピッチ等に基く、小球体の内部に比べて低結晶性の炭素質の極薄層が形成され、二層構造の小球体が得られる。   The mesophase carbon microspheres after particle size adjustment are further heated to a temperature of 2000 ° C. or higher, preferably 2500 ° C. or higher, so that the mesophase carbon microspheres (graphite) having high crystallinity adhere to the surface. Based on the pitch and the like, a carbonaceous ultrathin layer having a lower crystallinity than the inside of the small sphere is formed, and a two-layered small sphere is obtained.

前記小球体（基材）の表面の結晶性は、アルゴンレーザーを用いたラマンスペクトルによって評価される。ここで、基材の表面とは、小球体に通常付着している極薄層の表面を意味する。なお、本発明の負極材料の結晶性も同様に評価される。すなわち、黒鉛構造に基く９種の格子振動のうち、網面内格子振動に相当するＥ２ｇ型振動に対応した１５８０ｃｍ−１近傍のスペクトル強度（ＩＧ）と、主に表層での結晶欠陥、積層不整などの結晶構造の乱れを反映した１３６０ｃｍ−１近傍のスペクトル強度（ＩＤ）を、波長５１４．５ｎｍのアルゴンレーザーを用いたラマン分光分析器により測定する。そして、ピーク強度比（ＲＡ＝ＩＤ／ＩＧ、ＲＢ＝ＩＤ／ＩＧ)を算出する。 The crystallinity of the surface of the small sphere (base material) is evaluated by a Raman spectrum using an argon laser. Here, the surface of a base material means the surface of the ultra-thin layer normally attached to the small sphere. The crystallinity of the negative electrode material of the present invention is similarly evaluated. That is, out of nine types of lattice vibrations based on the graphite structure, spectral intensity (IG) in the vicinity of 1580 cm −1 corresponding to E2g type vibrations corresponding to in-plane lattice vibrations, crystal defects on the surface layer, stacking irregularities The spectral intensity (ID) in the vicinity of 1360 cm −1 reflecting the disorder of the crystal structure such as is measured by a Raman spectroscopic analyzer using an argon laser having a wavelength of 514.5 nm. Then, the peak intensity ratio (R A = ID / IG, R B = ID / IG) is calculated.

強度比ＲＡが大きなものほど基材の表面の結晶性が低いと評価される。強度比ＲＡは不可逆容量を小さくする観点から、ＲＡが０．０５〜０．３、特に好ましくは０．０８〜０．３である。表面の結晶性が高く、ＲＡが０．０５未満であると、不可逆容量が大きく、充分な電池特性（放電容量、初回充放電効率、レート特性）が得られない。これは、表面の結晶性が高すぎて非水電解液の分解反応が進行しやすくなるためと推考される。 It is evaluated that the larger the intensity ratio RA, the lower the crystallinity of the surface of the substrate. The intensity ratio R A from the viewpoint of reducing the irreversible capacity, R A is 0.05 to 0.3, particularly preferably 0.08 to 0.3. When the surface crystallinity is high and RA is less than 0.05, the irreversible capacity is large, and sufficient battery characteristics (discharge capacity, initial charge / discharge efficiency, rate characteristics) cannot be obtained. This is presumably because the surface crystallinity is too high and the decomposition reaction of the non-aqueous electrolyte proceeds easily.

前記基材の平均的な結晶性は、Ｘ線広角回折法における炭素網面層の面間隔ｄ００２および結晶子のＣ軸方向の大きさ（Ｌｃ）からも評価することができる。本発明の負極材料の結晶性も同様に評価することができる。すなわち、ＣｕＫα線をＸ線源、高純度シリコンを標準物質に使用して、基材に対し（００２）回折ピークを測定し、そのピーク位置およびその半値幅から、それぞれｄ００２、Ｌｃを算出する。算出方法は学振法（日本学術振興会第１１７委員会が定めた測定法）に従うものであり、具体的な方法は「炭素繊維」（大谷杉郎著、近代編集社、昭和６１年３月発行）の７３３〜７４２頁などに記載されている。 The average crystallinity of the substrate can also be evaluated from the interplanar spacing d002 of the carbon network layer and the size (Lc) of the crystallite in the C-axis direction in the X-ray wide angle diffraction method. The crystallinity of the negative electrode material of the present invention can be similarly evaluated. That is, using a CuKα ray as an X-ray source and high-purity silicon as a standard material, a (002) diffraction peak is measured with respect to the base material, and d 002 and Lc are calculated from the peak position and its half-value width, respectively. . The calculation method follows the Japan Science and Technology Act (measurement method established by the 117th Committee of the Japan Society for the Promotion of Science). The specific method is “carbon fiber” (by Suguro Otani, Modern Editorial Company, March 1986). Pp. 733-742.

前記基材の黒鉛構造の発達度合いの指標となるＸ線回折法によるｄ００２およびＬｃは、高い放電容量を発現させる観点から、ｄ００２≦０．３３６５ｎｍ、Ｌｃ≧４０ｎｍであることが好ましく、ｄ００２≦０．３３６２ｎｍ、Ｌｃ≧５０ｎｍであることが特に好ましい。ｄ００２＞０．３３６５ｎｍ、Ｌｃ＜４０ｎｍであると黒鉛構造の発達の程度が低いため、リチウムイオン二次電池の負極材料として用いたときに、リチウムのドープ量が少なく、高い放電容量が得られないことがある。 From the viewpoint of developing a high discharge capacity, d 002 and Lc, which are indicators of the degree of development of the graphite structure of the substrate, are preferably d 002 ≦ 0.3365 nm and Lc ≧ 40 nm. It is particularly preferable that 002 ≦ 0.3362 nm and Lc ≧ 50 nm. When d 002 > 0.3365 nm and Lc <40 nm, the degree of development of the graphite structure is low. Therefore, when used as a negative electrode material for a lithium ion secondary battery, the lithium doping amount is small and a high discharge capacity is obtained. There may not be.

また、前記基材は、その比表面積が大きすぎると初回充放電効率や安全性が低下するなどの問題があるので、窒素ガス吸着ＢＥＴ法による比表面積が２０ｍ２／ｇ以下、特に５ｍ２／ｇ以下であることが好ましい。 Moreover, since the said base material has problems, such as initial charge-and-discharge efficiency and safety | security, if the specific surface area is too large, the specific surface area by nitrogen gas adsorption BET method is 20 m < 2 > / g or less, Especially 5 m < 2 > / g or less is preferable.

〔付着物〕
前記基材に付着する付着物は、前記基材の表面より結晶性の低い炭素質物である。前記付着物は小球体の黒鉛化物が通常有する炭素質の極薄層とは結晶性が異なり、前記極薄層とは別の層を形成する。
前記炭素質物は、例えば、炭素質材料を６００℃以上、好ましくは８００℃以上の温度に加熱し炭化してなるものが好ましい。炭素質材料の種類は問わないが、石炭系または石油系のタールピッチ類および／または樹脂類であることが好ましい。具体的には、タールピッチ類としてコールタール、タール軽油、タール中油、タール重油、ナフタリン油、アントラセン油、コールタールピッチ、ピッチ油、メソフェーズピッチ、酸素架橋石油ピッチ、ヘビーオイルなどが挙げられる。特に好ましいのはコールタールピッチ、メソフェーズピッチなどである。樹脂類としては、ポリビニルアルコールなどの熱可塑性樹脂、フェノール樹脂、フラン樹脂などが挙げられる。 [Adherent]
The deposit that adheres to the substrate is a carbonaceous material that is less crystalline than the surface of the substrate. The deposit is different in crystallinity from the carbonaceous ultrathin layer usually possessed by the small spherical graphitized material, and forms a layer different from the ultrathin layer.
The carbonaceous material is preferably obtained by heating and carbonizing a carbonaceous material at a temperature of 600 ° C. or higher, preferably 800 ° C. or higher. The type of the carbonaceous material is not limited, but is preferably a coal-based or petroleum-based tar pitch and / or a resin. Specific examples of the tar pitch include coal tar, tar light oil, tar medium oil, tar heavy oil, naphthalene oil, anthracene oil, coal tar pitch, pitch oil, mesophase pitch, oxygen-crosslinked petroleum pitch, heavy oil and the like. Particularly preferred are coal tar pitch and mesophase pitch. Examples of the resins include thermoplastic resins such as polyvinyl alcohol, phenol resins, and furan resins.

〔負極材料〕
本発明の負極材料は、前記基材（小球体）の表面に、前記表面の炭素質の極薄層より結晶性の低い炭素質物の付着物を、別の層として有する構造体である。
前記基材表面に付着する炭素質物は、基材表面の少なくとも一部を被覆していればよいが、エッジ面を被覆していることが特に好ましい。また、前記付着物は膜状、繊維状、粒状などいかなる形態で付着していてもよく、これら複数の組み合わせであってもよい。 [Negative electrode material]
The negative electrode material of the present invention is a structure having, as a separate layer, a carbonaceous material deposit having lower crystallinity than the ultrathin carbonaceous layer on the surface of the substrate (small sphere).
The carbonaceous material adhering to the surface of the base material only needs to cover at least a part of the surface of the base material, but it is particularly preferable to cover the edge surface. Moreover, the said deposit | attachment may adhere in what forms, such as film | membrane form, fibrous form, and a granular form, and these multiple combinations may be sufficient as it.

本発明の負極材料における前記炭素質物の付着量は、負極材料１００質量％に対し、１〜５０質量％、好ましくは１〜２０質量％、より好ましくは１〜１０質量％である。付着量は、炭素質材料を付着させる処理前後における負極材料の質量から計算で求めることができる。
付着物による基材表面の被覆状態は特に限定されないが、全面を均一に被覆していることが好ましい。被覆率は、例えば、ラマン分光法などによって測定することができる。付着物の膜厚は特に限定されないが、１００ｎｍ以下であることが好ましい。膜厚は、例えば、粒子断面の透過型電子顕微鏡による観察などによって測定することができる。 The adhesion amount of the carbonaceous material in the negative electrode material of the present invention is 1 to 50% by mass, preferably 1 to 20% by mass, and more preferably 1 to 10% by mass with respect to 100% by mass of the negative electrode material. The amount of adhesion can be calculated from the mass of the negative electrode material before and after the treatment for adhering the carbonaceous material.
Although the covering state of the base material surface by the deposit is not particularly limited, it is preferable that the entire surface is uniformly coated. The coverage can be measured by, for example, Raman spectroscopy. The thickness of the deposit is not particularly limited, but is preferably 100 nm or less. The film thickness can be measured, for example, by observing the particle cross section with a transmission electron microscope.

本発明の負極材料のアルゴンレーザーのラマンスペクトルによる１５８０ｃｍ−１に対する１３６０ｃｍ−１のピーク強度比（ＲＢ）が０．３以上、より好ましくは０．３〜１．０、特に好ましくは０．４〜１．０である。ＲＢが前記範囲であると初回充放電効率やレート特性が向上するので好ましい。
また、負極材料の強度比ＲＢが基材の強度比ＲＡより大きい（ＲＡ＜ＲＢ）と、前記負極材料の最表面に位置する負極材料の結晶性が基材の結晶性（ＲＡが０．０５以上）より低いことを意味し、初回充放電効率が向上するので好ましい。より好ましいのは０．０５≦ＲＡ＜ＲＢ≦１．０である。 Peak intensity ratio of 1360 cm -1 relative to 1580 cm -1 by Raman spectrum of the argon laser of the negative electrode material of the present invention (R B) is 0.3 or more, more preferably 0.3 to 1.0, particularly preferably 0.4 -1.0. R B is preferred because the initial charge and discharge efficiency and rate characteristics can be improved if there in the above range.
Further, when the strength ratio R B of the negative electrode material is larger than the strength ratio R A of the base material (R A <R B ), the crystallinity of the negative electrode material located on the outermost surface of the negative electrode material is the crystallinity of the base material (R A is lower than 0.05), which is preferable because the initial charge / discharge efficiency is improved. More preferably, 0.05 ≦ R A <R B ≦ 1.0.

本発明の負極材料の平均粒子径は、体積換算の平均粒子径で１〜１００μｍ、特に１〜５０μｍ、さらに１〜３０μｍであることが好ましい。１μｍ以上であれば、負極の充填密度を高められるため体積当りの放電容量が向上し、１００μｍ以下であれば、サイクル特性やレート特性が向上する。体積換算の平均粒子径とは、レーザー回折式粒度分布計により粒度分布の累積度数が体積百分率で５０％となる粒子径である。
本発明の負極材料の比表面積は５ｍ２／ｇ以下、特に３ｍ２／ｇ以下、さらに２ｍ２／ｇ以下であることが好ましい。前記範囲内であれば、初回充放電効率が向上する。
本発明の負極材料のタップ密度は１．０ｇ／ｍ３以上、特に１．３ｇ／ｍ３以上、さらに１．４ｇ／ｍ３以上であることが好ましい。最も好ましくは１．４５ｇ／ｍ３以上である。前記範囲内であれば、初回充放電効率が向上する。
なお、タップ密度とは１５０ｃｍ３の容器に試料を充填し、３００回タップした後の密度を言う。 The average particle diameter of the negative electrode material of the present invention is preferably 1 to 100 μm, particularly 1 to 50 μm, more preferably 1 to 30 μm in terms of volume average particle diameter. If it is 1 μm or more, the packing density of the negative electrode can be increased, so that the discharge capacity per volume is improved, and if it is 100 μm or less, cycle characteristics and rate characteristics are improved. The average particle diameter in terms of volume is a particle diameter at which the cumulative frequency of particle size distribution is 50% by volume by a laser diffraction particle size distribution meter.
The specific surface area of the negative electrode material of the present invention is preferably 5 m 2 / g or less, particularly 3 m 2 / g or less, and more preferably 2 m 2 / g or less. If it is in the said range, initial charge-and-discharge efficiency will improve.
The tap density of the negative electrode material of the present invention is 1.0 g / m 3 or more, particularly 1.3 g / m 3 or more, and more preferably 1.4 g / m 3 or more. Most preferably, it is 1.45 g / m 3 or more. If it is in the said range, initial charge-and-discharge efficiency will improve.
The tap density means the density after a sample is filled in a 150 cm 3 container and tapped 300 times.

本発明の負極材料は、本発明の目的を損なわない範囲で、異種の黒鉛質材料、非晶質ハードカーボンなどの炭素質材料、有機物、金属、金属化合物などを混合しても、内包しても、被覆してもよい。また、本発明の負極材料は、液相、気相、固相における各種化学的処理、熱処理、物理的処理、酸化処理などを施されてもよい。
また、本発明の負極材料における基材と付着物との境界に、組成が傾斜的に変化する界面層が存在してもよい。例えば、付着処理にメカノケミカル処理を用いる場合、付着するピッチの研磨効果で、基材表面の極薄層の最表面の結晶性がやや乱される（結晶性が低下する）ことがあり得る。 The negative electrode material of the present invention is included within the range not impairing the object of the present invention, even if different types of graphite materials, carbonaceous materials such as amorphous hard carbon, organic substances, metals, metal compounds, etc. are mixed. May also be coated. The negative electrode material of the present invention may be subjected to various chemical treatments in the liquid phase, gas phase, and solid phase, heat treatment, physical treatment, oxidation treatment, and the like.
In addition, an interface layer whose composition changes in an inclined manner may exist at the boundary between the base material and the deposit in the negative electrode material of the present invention. For example, when a mechanochemical treatment is used for the adhesion treatment, the crystallinity of the outermost surface of the ultrathin layer on the substrate surface may be slightly disturbed (crystallinity is lowered) due to the polishing effect of the adhesion pitch.

〔付着方法〕
本発明における炭素質物の基材表面への付着は、いかなる方法によってもよいが、気相法、液相法、固相法によるのが好ましく、特に固相法によるのが好ましい。また、これらの複数の組み合わせであってもよい。本発明の代表的な炭素質物の基材表面への付着方法を以下に示す。 [Adhesion method]
The carbonaceous material in the present invention may be attached to the substrate surface by any method, but is preferably a gas phase method, a liquid phase method, or a solid phase method, particularly preferably a solid phase method. A combination of these may also be used. The method for attaching a typical carbonaceous material of the present invention to the substrate surface is shown below.

固相法としては炭素質材料の粉末と基材を圧縮、剪断、衝突、摩擦などの機械的エネルギーを付与するメカノケミカル処理などによって圧着する方法が挙げられる。このような操作が可能な装置としては、例えば、GRANUREX[フロイント産業（株）製]、ニューグラマシン[（株）セイシン企業製]、アグロマスター[ホソカワミクロン（株）製]などの造粒機、ロールミル、ハイブリダイゼーション[（株）奈良機械製作所製]、メカノマイクロシステム[（株）奈良機械製作所製]、メカノフュージョンシステム[ホソカワミクロン（株）製]などの圧縮剪断式加工装置などを挙げることができる。
炭素質材料については前述したが、特に好ましいのはコールタールピッチ、メソフェーズピッチなどである。 Examples of the solid-phase method include a method in which a carbonaceous material powder and a base material are pressure-bonded by mechanochemical treatment that imparts mechanical energy such as compression, shearing, collision, and friction. For example, granulators such as GRANUREX [manufactured by Freund Sangyo Co., Ltd.], Nyugra Machine [manufactured by Seishin Enterprise], Agromaster [manufactured by Hosokawa Micron Co., Ltd.], roll mills, etc. And compression shearing processing devices such as hybridization [manufactured by Nara Machinery Co., Ltd.], mechanomicrosystem [manufactured by Nara Machinery Co., Ltd.], mechanofusion system [manufactured by Hosokawa Micron Corporation], and the like.
Although the carbonaceous material has been described above, coal tar pitch, mesophase pitch, and the like are particularly preferable.

気相法としては、基材にベンゼンなどの炭化水素の蒸気を高温で蒸着する方法が挙げられる。
液相法としては炭素質材料の溶液に基材を分散したのち、溶媒を除去する方法が挙げられる。 Examples of the vapor phase method include a method in which a vapor of a hydrocarbon such as benzene is deposited on a substrate at a high temperature.
Examples of the liquid phase method include a method of dispersing a base material in a solution of a carbonaceous material and then removing the solvent.

いずれの方法で形成された炭素質物も、不活性雰囲気中、９００〜１５００℃、好ましくは１０００〜１３００℃の温度で加熱することによって炭化されるので、電池特性をより向上させることができる。   Since the carbonaceous material formed by any method is carbonized by heating at a temperature of 900 to 1500 ° C., preferably 1000 to 1300 ° C. in an inert atmosphere, the battery characteristics can be further improved.

本発明の負極材料を用いた場合に、初回充放電効率、レート特性などが改良されるメカニズムについては明らかではないが、次のように推定される。すなわち、通常は低結晶性の黒鉛質層を有する黒鉛化物（基材）の表面が、さらに低結晶性の炭素質物の薄層で被覆されているため、黒鉛化物のエッジ面での非水電解液の分解が生じにくく、たとえ、炭素質物の薄層が損傷したとしても、黒鉛化物内部の結晶性の最高部は、それ自身が元から有する低結晶性の黒鉛質層に覆われているためエッジ面の露出部分が少なく、非水電解液の分解による初回充放電効率の低下を生じることがない。   When the negative electrode material of the present invention is used, the mechanism by which the initial charge / discharge efficiency, rate characteristics, and the like are improved is not clear, but is estimated as follows. In other words, since the surface of the graphitized material (base material) having a low crystalline graphite layer is usually covered with a thin layer of a low crystalline carbonaceous material, non-aqueous electrolysis is performed on the edge surface of the graphitized material. Even if the thin layer of carbonaceous material is damaged, the highest part of the crystallinity inside the graphitized material is covered with the low crystalline graphite layer that it originally has. The exposed portion of the edge surface is small, and the initial charge / discharge efficiency is not lowered due to the decomposition of the non-aqueous electrolyte.

また、本発明は、基材として光学的異方性を有するメソフェーズカーボン小球体の粉砕品を黒鉛化した黒鉛化物を用いるため、負極内の粒子の配向が小さく、負極内でのリチウムイオンの拡散性が向上する。また、粉砕によって適度な粒子径範囲・粒度分布に調整されているため、負極内において粒子間接点が充分に確保され、電子伝導性が向上する。これらの要因によって良好なレート特性が発現するものと推考される。   In addition, since the present invention uses a graphitized product obtained by graphitizing a pulverized mesophase carbon microsphere having optical anisotropy as a base material, the orientation of particles in the negative electrode is small, and the diffusion of lithium ions in the negative electrode Improves. Moreover, since it is adjusted to an appropriate particle size range and particle size distribution by pulverization, particle indirect points are sufficiently ensured in the negative electrode, and electron conductivity is improved. It is assumed that good rate characteristics are manifested by these factors.

〔負極〕
本発明は、前記負極材料を含有するリチウムイオン二次電池用負極であり、該負極を用いるリチウムイオン二次電池である。
本発明の負極は、通常の負極の成形方法に準じて作製されるが、本発明の負極材料の電池特性を充分に引き出し、かつ賦型性が高く、化学的、電気化学的に安定な負極を得ることができる成形方法であれば何ら制限されない。
負極の作製時には、本発明の負極材料に結合剤を加えて調製した負極合剤を用いることが好ましい。結合剤としては、非水電解質に対して、化学的および電気化学的に安定なものが好ましく、例えば、ポリテトラフルオロエチレン、ポリフッ化ビニリデンなどのフッ素系樹脂粉末、ポリエチレン、ポリビニルアルコールなどの樹脂粉末、カルボキシメチルセルロースなどが用いられる。これらを併用することもできる。結合剤は、通常、負極合剤全量中の１〜２０質量％程度の割合で用いられる。 [Negative electrode]
The present invention is a negative electrode for a lithium ion secondary battery containing the negative electrode material, and is a lithium ion secondary battery using the negative electrode.
The negative electrode of the present invention is produced according to a normal method of forming a negative electrode. However, the negative electrode material of the present invention sufficiently draws out battery characteristics, has high moldability, and is chemically and electrochemically stable. There is no limitation as long as it is a molding method capable of obtaining the above.
When preparing the negative electrode, it is preferable to use a negative electrode mixture prepared by adding a binder to the negative electrode material of the present invention. As the binder, those that are chemically and electrochemically stable with respect to the non-aqueous electrolyte are preferable. For example, fluorine-based resin powders such as polytetrafluoroethylene and polyvinylidene fluoride, and resin powders such as polyethylene and polyvinyl alcohol Carboxymethyl cellulose and the like are used. These can also be used together. A binder is normally used in the ratio of about 1-20 mass% in the negative electrode mixture whole quantity.

具体的には、まず、本発明の負極材料を分級などにより所望の粒度に調整し、結合剤と混合して得た混合物を溶剤に分散させ、ペースト状にして負極合剤を調製する。すなわち、本発明の負極材料と結合剤を、水、イソプロピルアルコール、Ｎ−メチルピロリドン、ジメチルホルムアミドなどの溶剤と混合して得たスラリーを、公知の攪拌機、混合機、混練機、ニーダーなどを用いて攪拌混合して、負極合剤ペーストを調製する。該ペーストを、集電材の片面または両面に塗布し、乾燥すれば、負極合剤層が均一かつ強固に接着した負極が得られる。負極合剤層の膜厚は１０〜２００μｍ、好ましくは２０〜１００μｍである。   Specifically, first, the negative electrode material of the present invention is adjusted to a desired particle size by classification or the like, and a mixture obtained by mixing with a binder is dispersed in a solvent to prepare a negative electrode mixture in the form of a paste. That is, a slurry obtained by mixing the negative electrode material and the binder of the present invention with a solvent such as water, isopropyl alcohol, N-methylpyrrolidone, dimethylformamide, etc., using a known stirrer, mixer, kneader, kneader or the like. The mixture is stirred and mixed to prepare a negative electrode mixture paste. When the paste is applied to one or both sides of the current collector and dried, a negative electrode in which the negative electrode mixture layer is uniformly and firmly bonded is obtained. The film thickness of the negative electrode mixture layer is 10 to 200 μm, preferably 20 to 100 μm.

また、本発明の負極は、本発明の負極材料と、ポリエチレン、ポリビニルアルコールなどの樹脂粉末を乾式混合し、金型内でホットプレス成形して作製することもできる。   The negative electrode of the present invention can also be produced by dry-mixing the negative electrode material of the present invention and resin powders such as polyethylene and polyvinyl alcohol and hot pressing in a mold.

負極合剤層を形成した後、プレス加圧などの圧着を行うと、負極合剤層と集電材との接
着強度をさらに高めることができる。
負極の作製に用いる集電材の形状は、特に限定されないが、箔状、メッシュ、エキスパンドメタルなどの網状物などが好ましい。集電材の材質としては、銅、ステンレス、ニッケルなどが好ましい。集電材の厚みは、箔状の場合は好ましくは５〜２０μｍである。 After the negative electrode mixture layer is formed, the adhesive strength between the negative electrode mixture layer and the current collector can be further increased by press bonding such as pressurization.
The shape of the current collector used for producing the negative electrode is not particularly limited, but is preferably a foil, a mesh, or a net-like material such as expanded metal. The material for the current collector is preferably copper, stainless steel, nickel or the like. The thickness of the current collector is preferably 5 to 20 μm in the case of a foil.

なお、本発明の負極は、本発明の目的を損なわない範囲で、異種の黒鉛質材料、非晶質ハードカーボンなどの炭素質材料、有機物、金属、金属化合物などを混合しても、内包しても、被覆しても、積層してもよい。   It should be noted that the negative electrode of the present invention can be included even if different types of graphite materials, carbonaceous materials such as amorphous hard carbon, organic substances, metals, metal compounds, and the like are mixed within a range that does not impair the object of the present invention. Alternatively, it may be coated or laminated.

また、本発明の負極は、２５０ＭＰａでプレスされた状態でのＸ線回折スペクトルにおける黒鉛の（００４）面と（１１０）面のピーク強度比Ｉ（００４）／Ｉ（１１０）が４以下であり、一般的な黒鉛の強度比の範囲内にある。前記強度比は、その比の値が小さいほど負極内の粒子配向が小さいことを意味する。   In the negative electrode of the present invention, the peak intensity ratio I (004) / I (110) of the (004) plane and the (110) plane of graphite in an X-ray diffraction spectrum pressed at 250 MPa is 4 or less. In the range of the strength ratio of general graphite. The intensity ratio means that the smaller the value of the ratio, the smaller the particle orientation in the negative electrode.

［正極］
正極は、例えば正極材料と結合剤および導電剤よりなる正極合剤を集電材の表面に塗布することにより形成される。正極材料（正極活物質）は、充分量のリチウムを吸蔵／脱離し得るものを選択するのが好ましく、リチウム含有遷移金属酸化物、遷移金属カルコゲン化物、バナジウム酸化物およびそのリチウム化合物などのリチウム含有化合物、一般式 ＭＸＭＯ６Ｓ８−Ｙ（式中、Ｍは少なくとも一種の遷移金属元素であり、Ｘは０≦Ｘ≦４、Ｙは０≦Ｘ≦１の範囲の数値である）で表されるシェブレル相化合物、活性炭、活性炭素繊維などである。 [Positive electrode]
The positive electrode is formed, for example, by applying a positive electrode mixture comprising a positive electrode material, a binder and a conductive agent to the surface of the current collector. It is preferable to select a positive electrode material (positive electrode active material) that can absorb / desorb a sufficient amount of lithium. The lithium-containing transition metal oxide, transition metal chalcogenide, vanadium oxide, and lithium-containing compounds such as lithium compounds thereof are preferable. Compound, general formula M X MO 6 S 8 -Y (wherein M is at least one transition metal element, X is a numerical value in the range of 0 ≦ X ≦ 4, Y is 0 ≦ X ≦ 1) Chevrel phase compounds, activated carbon, activated carbon fibers and the like.

リチウム含有遷移金属酸化物は、リチウムと遷移金属との複合酸化物であり、リチウムと２種類以上の遷移金属を固溶したものであってもよい。複合酸化物は単独で使用しても、２種類以上を組合せて使用してもよい。
リチウム含有遷移金属酸化物は、ＬｉＭ１ １−ＸＭ２ ＸＯ２（式中、Ｍ1、Ｍ２は少なくとも一種の遷移金属元素であり、Ｘは０≦Ｘ≦１の範囲の数値である）、またはＬｉＭ１ １−ＹＭ２ ＹＯ４（式中、Ｍ1、Ｍ２は少なくとも一種の遷移金属元素であり、Ｙは０≦Ｙ≦１の範囲の数値である）で示される。 The lithium-containing transition metal oxide is a composite oxide of lithium and a transition metal, and may be a solid solution of lithium and two or more transition metals. The composite oxide may be used alone or in combination of two or more.
The lithium-containing transition metal oxide is LiM 1 1-X M 2 X O 2 (wherein M 1 and M 2 are at least one transition metal element, and X is a numerical value in the range of 0 ≦ X ≦ 1. ), Or LiM 1 1-Y M 2 Y O 4 (wherein M 1 and M 2 are at least one transition metal element, and Y is a numerical value in the range of 0 ≦ Y ≦ 1).

Ｍ1、Ｍ２で示される遷移金属元素は、Ｃｏ、Ｎｉ、Ｍｎ、Ｃｒ、Ｔｉ、Ｖ、Ｆｅ、Ｚｎ、Ａｌ、Ｉｎ、Ｓｎなどであり、好ましいのはＣｏ、Ｍｎ、Ｃｒ、Ｔｉ、Ｖ、Ｆｅ、Ａｌなどである。好ましい遷移金属酸化物は、ＬｉＣｏＯ２、ＬｉＮｉＯ２、ＬｉＭｎＯ２、ＬｉＮｉ０．９Ｃｏ０．１Ｏ２、ＬｉＮi０．５Ｃｏ０．５Ｏ２などである。
バナジウム酸化物はＶ２Ｏ５、Ｖ６Ｏ１３、Ｖ２Ｏ４、Ｖ３Ｏ８で示されるものである。 The transition metal elements represented by M 1 and M 2 are Co, Ni, Mn, Cr, Ti, V, Fe, Zn, Al, In, Sn, etc., preferably Co, Mn, Cr, Ti, V Fe, Al and the like. Preferred transition metal oxides include LiCoO 2 , LiNiO 2 , LiMnO 2 , LiNi 0.9 Co 0.1 O 2 , LiNi 0.5 Co 0.5 O 2 and the like.
Vanadium oxide is one represented by V 2 O 5, V 6 O 13, V 2 O 4, V 3 O 8.

リチウム含有遷移金属酸化物は、例えば、リチウム、遷移金属の酸化物、水酸化物、塩類等を出発原料とし、これら出発原料を所望の金属酸化物の組成に応じて混合し、酸素雰囲気下６００〜１０００℃の温度で焼成することにより得ることができる。   Examples of the lithium-containing transition metal oxide include lithium, transition metal oxides, hydroxides, salts, and the like as starting materials, and these starting materials are mixed in accordance with the composition of the desired metal oxide, and are mixed under an oxygen atmosphere. It can be obtained by firing at a temperature of ˜1000 ° C.

正極活物質は、前記酸化物を単独で使用しても２種類以上併用してもよい。例えば、正極中に炭酸リチウム等の炭素塩を添加することができる。また、正極を形成するに際しては、従来公知の導電剤などの各種添加剤を適宜に使用することができる。   The positive electrode active material may be used alone or in combination of two or more. For example, a carbon salt such as lithium carbonate can be added to the positive electrode. Moreover, when forming a positive electrode, conventionally well-known various additives, such as a electrically conductive agent, can be used suitably.

正極は、正極材料、結合剤、および正極に導電性を付与するための導電剤よりなる正極合剤を、集電材の両面に塗布して正極合剤層を形成して作製される。結合剤としては、負極の作製に使用されるものと同じものが使用可能である。導電剤としては、黒鉛化物など公知のものが使用される。
集電材の形状は特に限定されないが、箔状またはメッシュ、エキスパンドメタル等の網状等のものが用いられる。集電材の材質は、アルミニウム、ステンレス、ニッケル等である。その厚さは１０〜４０μｍのものが好適である。 The positive electrode is manufactured by applying a positive electrode mixture made of a positive electrode material, a binder, and a conductive agent for imparting conductivity to the positive electrode on both surfaces of the current collector to form a positive electrode mixture layer. As the binder, the same one as that used for producing the negative electrode can be used. As the conductive agent, known ones such as graphitized materials are used.
The shape of the current collector is not particularly limited, and a foil or mesh or net-like material such as expanded metal is used. The material of the current collector is aluminum, stainless steel, nickel or the like. The thickness is preferably 10 to 40 μm.

正極も負極と同様に、正極合剤を溶剤中に分散させペースト状にし、このペースト状の正極合剤を集電材に塗布、乾燥して正極合剤層を形成してもよく、正極合剤層を形成した後、さらにプレス加圧等の圧着を行ってもよい。これにより正極合剤層が均一且つ強固に集電材に接着される。   Similarly to the negative electrode, the positive electrode mixture may be dispersed in a solvent to form a paste, and the paste-like positive electrode mixture may be applied to a current collector and dried to form a positive electrode mixture layer. After the layer is formed, pressure bonding such as press pressing may be further performed. As a result, the positive electrode mixture layer is uniformly and firmly bonded to the current collector.

［非水電解質］
本発明に用いられる非水電解質は、通常の非水電解液に使用される電解質の塩である。例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣｌＯ４、ＬｉＢ（Ｃ６Ｈ５）、ＬｉＣｌ、ＬｉＢｒ、ＬｉＣＦ３ＳＯ３、ＬｉＣＨ３ＳＯ３、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＮ（ＣＦ３ＣＨ２ＯＳＯ２）２、ＬｉＮ（ＣＦ３ＣＦ２ＯＳＯ２）２、ＬｉＮ（ＨＣＦ２ＣＦ２ＣＨ２ＯＳＯ２）２、ＬｉＮ［（ＣＦ３）２ＣＨＯＳＯ２］２、ＬｉＢ［Ｃ６Ｈ３（ＣＦ３）２］４、ＬｉＡｌＣｌ４、ＬｉＳｉＦ６などのリチウム塩を用いることができる。特にＬｉＰＦ６、ＬｉＢＦ４が酸化安定性の点から好ましく用いられる。
非水電解液中の電解質塩濃度は０．１〜５mol/lが好ましく、０．５〜３．０mol/l がより好ましい。 [Nonaqueous electrolyte]
The nonaqueous electrolyte used in the present invention is a salt of an electrolyte used for a normal nonaqueous electrolyte. For example, LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB (C 6 H 5 ), LiCl, LiBr, LiCF 3 SO 3 , LiCH 3 SO 3 , LiN (CF 3 SO 2 ) 2 , LiC (CF 3 SO 2 ) 3 , LiN (CF 3 CH 2 OSO 2 ) 2 , LiN (CF 3 CF 2 OSO 2 ) 2 , LiN (HCF 2 CF 2 CH 2 OSO 2 ) 2 , LiN [(CF 3 ) 2 CHOSO 2 ] 2 LiB [C 6 H 3 (CF 3 ) 2 ] 4 , LiAlCl 4 , LiSiF 6 and other lithium salts can be used. In particular, LiPF 6 and LiBF 4 are preferably used from the viewpoint of oxidation stability.
The electrolyte salt concentration in the non-aqueous electrolyte is preferably 0.1 to 5 mol / l, more preferably 0.5 to 3.0 mol / l.

非水電解質は液状電解質としてもよく、固体電解質またはゲル電解質などの高分子電解質としてもよい。液状電解質の場合は、非水電解質電池はいわゆるリチウムイオン二次電池として構成され、高分子電解質の場合は、高分子固体電解質電池、高分子ゲル電解質電池などの高分子電解質電池として構成される。   The non-aqueous electrolyte may be a liquid electrolyte or a polymer electrolyte such as a solid electrolyte or a gel electrolyte. In the case of a liquid electrolyte, the nonaqueous electrolyte battery is configured as a so-called lithium ion secondary battery, and in the case of a polymer electrolyte, it is configured as a polymer electrolyte battery such as a polymer solid electrolyte battery or a polymer gel electrolyte battery.

非水電解液を調製するための溶媒としては、エチレンカーボネート、プロピレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネートなどのカーボネート、１，1−または１，2−ジメトキシエタン、１，2−ジエトキシエタン、テトラヒドロフラン、２−メチルテトラヒドロフラン、γ−ブチロラクトン、1，３−ジオキソラン、4−メチル−1，3−ジオキソフラン、アニソール、ジエチルエーテルなどのエーテル、スルホラン、メチルスルホランなどのチオエーテル、アセトニトリル、クロロニトリル、プロピオニトリルなどのニトリル、ホウ酸トリメチル、ケイ酸テトラメチル、ニトロメタン、ジメチルホルムアミド、Ｎ−メチルピロリドン、酢酸エチル、トリメチルオルトホルメート、ニトロベンゼン、塩化ベンゾイル、臭化ベンゾイル、テトラヒドロチオフェン、ジメチルスルホキシド、３−メチル−２−オキサゾリドン、エチレングリコール、ジメチルサルファイトなどの非プロトン性有機溶媒を用いることができる。   Solvents for preparing the non-aqueous electrolyte include carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, 1,1- or 1,2-dimethoxyethane, 1,2-diethoxy Ethane, tetrahydrofuran, 2-methyltetrahydrofuran, γ-butyrolactone, 1,3-dioxolane, 4-methyl-1,3-dioxofuran, ethers such as anisole and diethyl ether, thioethers such as sulfolane and methylsulfolane, acetonitrile, chloronitrile, Nitriles such as propionitrile, trimethyl borate, tetramethyl silicate, nitromethane, dimethylformamide, N-methylpyrrolidone, ethyl acetate, trimethyl orthoformate, nitrobenzene, Benzoyl, benzoyl bromide, tetrahydrothiophene, dimethyl sulfoxide, 3-methyl-2-oxazolidone, ethylene glycol, may be used an aprotic organic solvent such as dimethyl sulfite.

非水電解質を高分子電解質とする場合には、マトリックスとして可塑剤（非水電解液）でゲル化された高分子化合物を用いることが好ましい。前記高分子化合物としては、ポリエチレンオキサイドやその架橋体などのエーテル系高分子化合物、ポリメタクリレート系高分子化合物、ポリアクリレート系高分子化合物、ポリビニリデンフルオライドやビニリデンフルオライド−ヘキサフルオロプロピレン共重合体などのフッ素系高分子化合物などを単独または混合して用いることができる。
これらの中で、酸化還元安定性の観点などから、ポリビニリデンフルオライドやビニリデンフルオライド−ヘキサフルオロプロピレン共重合体などのフッ素系高分子化合物を用いることが好ましい。 When the non-aqueous electrolyte is a polymer electrolyte, it is preferable to use a polymer compound gelled with a plasticizer (non-aqueous electrolyte) as a matrix. Examples of the polymer compound include ether polymer compounds such as polyethylene oxide and cross-linked products thereof, polymethacrylate polymer compounds, polyacrylate polymer compounds, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene copolymers. Fluorine polymer compounds such as can be used alone or in combination.
Among these, it is preferable to use a fluorine-based polymer compound such as polyvinylidene fluoride or vinylidene fluoride-hexafluoropropylene copolymer from the viewpoint of redox stability.

高分子固体電解質の作製方法は特に限定されないが、例えば、マトリックスを構成する高分子化合物、リチウム塩および非水溶媒（可塑剤）を混合し、加熱して高分子化合物を溶融・溶解する方法、混合用有機溶媒に、高分子化合物、リチウム塩、および非水溶媒（可塑剤）を溶解させた後、混合用有機溶媒を蒸発させる方法、重合性モノマー、リチウム塩および非水溶媒（可塑剤）を混合し、混合物に紫外線、電子線または分子線などを照射して、重合性モノマーを重合させ、ポリマーを得る方法などを挙げることができる。
前記固体電解質中の非水溶媒（可塑剤）の割合は１０〜９０質量％が好ましく、３０〜８０質量％がより好ましい。１０質量％未満であると導電率が低くなり、９０質量％超であると機械的強度が低下し、製膜しにくくなる。 The method for producing the solid polymer electrolyte is not particularly limited. For example, a method of mixing a polymer compound constituting a matrix, a lithium salt and a nonaqueous solvent (plasticizer), and heating and melting and dissolving the polymer compound, Method of evaporating organic solvent for mixing after dissolving polymer compound, lithium salt and non-aqueous solvent (plasticizer) in organic solvent for mixing, polymerizable monomer, lithium salt and non-aqueous solvent (plasticizer) And a method of obtaining a polymer by polymerizing a polymerizable monomer by irradiating the mixture with ultraviolet rays, an electron beam, a molecular beam or the like.
10-90 mass% is preferable, and, as for the ratio of the nonaqueous solvent (plasticizer) in the said solid electrolyte, 30-80 mass% is more preferable. If it is less than 10% by mass, the electrical conductivity will be low, and if it is more than 90% by mass, the mechanical strength will be reduced and film formation will be difficult.

〔セパレータ〕
本発明のリチウムイオン二次電池においては、セパレータを使用することもできる。
セパレータは特に限定されるものではないが、例えば織布、不織布、合成樹脂製微多孔膜などが挙げられる。合成樹脂製微多孔膜が好適であるが、なかでもポリオレフィン系微多孔膜が、厚さ、膜強度、膜抵抗の面で好適である。具体的には、ポリエチレンおよびポリプロピレン製微多孔膜、またはこれらを複合した微多孔膜等である。 [Separator]
In the lithium ion secondary battery of the present invention, a separator can also be used.
Although a separator is not specifically limited, For example, a woven fabric, a nonwoven fabric, a synthetic resin microporous film, etc. are mentioned. A synthetic resin microporous membrane is preferred, and among them, a polyolefin microporous membrane is preferred in terms of thickness, membrane strength, and membrane resistance. Specifically, it is a microporous membrane made of polyethylene and polypropylene, or a microporous membrane that combines these.

［リチウムイオン二次電池］
本発明のリチウムイオン二次電池は、前記の少なくともリチウムと合金化可能な金属と黒鉛化物を含む負極材料において、前記金属と黒鉛化物が、炭素質材料以外の導電性材料で結合または被覆された負極、正極および非水電解質を、例えば、負極、非水電解質、正極の順で積層し、二次電池の外装材内に収容することで構成される。さらに、負極と正極の外側に非水電解質を配するようにしてもよい。 [Lithium ion secondary battery]
In the lithium ion secondary battery of the present invention, in the negative electrode material containing at least the metal alloyable with lithium and the graphitized material, the metal and the graphitized material are bonded or coated with a conductive material other than the carbonaceous material. For example, the negative electrode, the positive electrode, and the non-aqueous electrolyte are stacked in the order of the negative electrode, the non-aqueous electrolyte, and the positive electrode, and are accommodated in the exterior material of the secondary battery. Further, a non-aqueous electrolyte may be disposed outside the negative electrode and the positive electrode.

また、本発明のリチウムイオン二次電池の構造は特に限定されず、その形状、形態について特に限定されるものではなく、用途、搭載機器、要求される充放電容量などに応じて円筒型、角型、コイン型、ボタン型などの中から任意に選択することができる。より安全性の高い密閉型非水電解液電池を得るためには、過充電などの異常時に電池内圧上昇を感知して電流を遮断させる手段を備えたものであることが好ましい。
高分子固体電解質電池や高分子ゲル電解質電池の場合には、ラミネートフィルムに封入した構造とすることもできる。 Further, the structure of the lithium ion secondary battery of the present invention is not particularly limited, and the shape and form thereof are not particularly limited. The shape and form of the lithium ion secondary battery are not particularly limited. It can be arbitrarily selected from a mold, a coin mold, a button mold, and the like. In order to obtain a sealed nonaqueous electrolyte battery with higher safety, it is preferable to include a means for detecting an increase in the internal pressure of the battery and shutting off the current when there is an abnormality such as overcharging.
In the case of a polymer solid electrolyte battery or a polymer gel electrolyte battery, a structure enclosed in a laminate film can also be used.

次に本発明を実施例により具体的に説明するが、本発明はこれら実施例に限定されるものではない。また以下の実施例、参考例および比較例では、図１に示すように、少なくとも表面の一部にリチウムと合金化可能な金属が付着した集電体（負極）７ｂとリチウム箔よりなる対極（正極）４から構成される単極評価用のボタン型二次電池を作製して評価した。実電池は、本発明の概念に基づき、公知の方法に準じて作製することができる。   EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In the following Examples, Reference Examples and Comparative Examples, as shown in FIG. 1, a current collector (negative electrode) 7b having a metal alloyable with lithium attached to at least a part of its surface and a counter electrode comprising a lithium foil ( A button type secondary battery for single electrode evaluation composed of (positive electrode) 4 was prepared and evaluated. An actual battery can be produced according to a known method based on the concept of the present invention.

（参考例１）
［負極材料の作製］
フリーカーボン（ＱＩ）を０．５質量％含有するコールタールを、３５０℃で０．５時間加熱した後、さらに４５０℃で０．２時間加熱してメソフェーズカーボン小球体を生成させた。加熱後のコールタールから、タール重油（沸点：２００〜３００℃）を用いてピッチを抽出し、ピッチマトリックスから濾過により、メソフェーズカーボン小球体を分離した。得られた小球体をロータリーキルンを用い５００℃で焼成し、得られた焼成生成物を２００メッシュ（篩目：７５μｍ）の振動篩を用いて、粗粒（凝集体）を除去した。得られた粒度調整品をジェット粉砕機［（株）セイシン企業製；型式コジェットシステムα−ｍｋIV］を用いて粉砕し、平均粒子径が１５μｍの粉砕品を得た。得られた粉砕品を黒鉛るつぼに入れ、アルゴン雰囲気下、昇温速度１０００℃／時間で昇温し、３０００℃で３時間懸けて黒鉛化し、小球体の黒鉛化物（基材）を得た。 (Reference Example 1)
[Production of negative electrode material]
Coal tar containing 0.5% by mass of free carbon (QI) was heated at 350 ° C. for 0.5 hour, and further heated at 450 ° C. for 0.2 hour to produce mesophase carbon microspheres. Pitch was extracted from coal tar after heating using tar heavy oil (boiling point: 200 to 300 ° C.), and mesophase carbon microspheres were separated from the pitch matrix by filtration. The obtained spherules were fired at 500 ° C. using a rotary kiln, and coarse particles (aggregates) were removed from the obtained fired product using a 200-mesh (sieve: 75 μm) vibrating sieve. The obtained particle size-adjusted product was pulverized using a jet pulverizer [manufactured by Seishin Co., Ltd .; model cojet system α-mkIV] to obtain a pulverized product having an average particle diameter of 15 μm. The obtained pulverized product was put into a graphite crucible, heated at a rate of temperature increase of 1000 ° C./hour in an argon atmosphere, and graphitized at 3000 ° C. for 3 hours to obtain a graphitized product (base material) of small spheres.

一方、炭素質材料のメソフェーズピッチをジェット粉砕機［（株）セイシン企業製；コジェットシステムα−ｍｋIV］を用いて粉砕し、平均粒子径を１０μｍに調整した。
前記基材と前記メソフェーズピッチの粉砕品を質量比１００：５で混合し、乾式粉体複合化装置［メカノフュージョンシステム、型式AMS、ホソカワミクロン（株）製］を用いて、回転ドラムの周速２０ｍ／秒、回転ドラムと内部部材との距離５ｍｍで６０分間圧縮力、剪断力を繰返し付与してメカノケミカル処理し、前記基材の表面に前記メソフェーズピッチの粉砕品が付着した基材を得た。得られた基材を１３００℃で加熱し、付着した前記メソフェーズピッチの粉砕品を炭化し、負極材料を作製した。得られた負極材料の外観を示す走査型電子顕微鏡写真を図２に示した。 On the other hand, the mesophase pitch of the carbonaceous material was pulverized using a jet pulverizer [manufactured by Seishin Enterprise Co., Ltd .; Kodget System α-mkIV], and the average particle size was adjusted to 10 μm.
The base material and the pulverized mesophase pitch were mixed at a mass ratio of 100: 5, and the peripheral speed of the rotating drum was 20 m using a dry powder compounding apparatus [Mechano-Fusion System, Model AMS, manufactured by Hosokawa Micron Corporation]. / Second, a compression force and a shear force were repeatedly applied for 60 minutes at a distance of 5 mm between the rotating drum and the internal member, and a mechanochemical treatment was performed to obtain a base material on which the pulverized product of the mesophase pitch adhered to the surface of the base material. . The obtained base material was heated at 1300 ° C., and the adhered pulverized mesophase pitch was carbonized to prepare a negative electrode material. A scanning electron micrograph showing the appearance of the obtained negative electrode material is shown in FIG.

〔負極合剤の作製〕
前記負極材料９０質量％とポリフッ化ビニリデン１０質量％をＮ−メチルピロリドンに入れ、ホモミキサーを用いて２０００ｒｐｍで３０分間攪拌混合し、負極合剤のペーストを調製した。 (Preparation of negative electrode mixture)
90% by mass of the negative electrode material and 10% by mass of polyvinylidene fluoride were placed in N-methylpyrrolidone, and the mixture was stirred and mixed at 2000 rpm for 30 minutes using a homomixer to prepare a negative electrode mixture paste.

〔作用電極（負極）の作製〕
前記負極合剤ペーストを、集電体の銅箔（厚み１５μｍ）上に均一な厚さで塗布した後、真空中９０℃でＮ−メチルピロリドンを揮発させて乾燥した。前記銅箔上に形成された負極合剤層をハンドプレスによって加圧し圧着した。ついで、直径１５．５ｍｍの円柱に打抜いて、負極材料が銅箔に密着した作用電極（対極）（厚み７０μｍ）を作製した。 [Production of working electrode (negative electrode)]
The negative electrode mixture paste was applied to a collector copper foil (thickness: 15 μm) with a uniform thickness, and then N-methylpyrrolidone was volatilized at 90 ° C. in a vacuum to dry the paste. The negative electrode mixture layer formed on the copper foil was pressed and pressed by a hand press. Next, a working electrode (counter electrode) (thickness 70 μm) in which the negative electrode material was in close contact with the copper foil was produced by punching into a cylinder having a diameter of 15.5 mm.

［対極の作製］
リチウム金属箔（厚み０．５ｍｍ）をニッケルネットに押付け、直径１５．５ｍｍの円形に打抜いて、ニッケルネットからなる集電体と、前記集電体に密着したリチウム金属箔からなる対極（正極）を作製した。 [Production of counter electrode]
A lithium metal foil (thickness 0.5 mm) is pressed onto a nickel net and punched into a circular shape with a diameter of 15.5 mm, and a current collector made of nickel net and a counter electrode made of a lithium metal foil in close contact with the current collector (positive electrode) ) Was produced.

［電解質・セパレータ］
エチレンカーボネート３３vol％−メチルエチルカーボネート６７vol％の混合溶媒に、ＬｉＰＦ6を１mol/Lとなる濃度で溶解させ、非水電解液を調製した。得られた非水電解液をポリプロピレン多孔質体（厚み２０μｍ）に含浸させ、電解質液が含浸したセパレータを作製した。 [Electrolyte / Separator]
LiPF6 was dissolved at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate 33 vol% -methylethyl carbonate 67 vol% to prepare a non-aqueous electrolyte. The obtained nonaqueous electrolytic solution was impregnated into a polypropylene porous body (thickness 20 μm) to produce a separator impregnated with the electrolytic solution.

［評価電池の作製］
評価電池は、図１に示す構造のボタン型二次電池であり、下記のように作製した。
外装カップ１と外装缶３は、その周縁部において絶縁ガスケット６を介在させ、両周縁部をかしめて密閉した。その外装缶３に内面から順に、ニッケルネットからなる集電体７ａ、リチウム箔よりなる円柱状の対極４、電解液が含浸したセパレータ５、作用電極２、銅箔からなる集電体７ｂが積層された電池である。
電解液を含浸したセパレータ５を、集電体７ｂと集電体７ａに密着した対極４との間に挟んで積層した後、集電体７ｂを外装カップ１内に、対極４を外装缶３内に収容して、外装カップ１と外装缶３とを合せ、さらに、外装カップ１と外装缶３との周縁部に絶縁ガスケット６を介在させ、両周縁部をかしめて密閉し作製した。 [Production of evaluation battery]
The evaluation battery is a button-type secondary battery having the structure shown in FIG. 1 and was produced as follows.
The exterior cup 1 and the exterior can 3 were sealed by interposing an insulating gasket 6 at the peripheral portion thereof and caulking both peripheral portions. On the outer can 3, a current collector 7 a made of nickel net, a columnar counter electrode 4 made of lithium foil, a separator 5 impregnated with an electrolyte, a working electrode 2, and a current collector 7 b made of copper foil are laminated in this order from the inner surface. Battery.
After the separator 5 impregnated with the electrolytic solution is sandwiched and stacked between the current collector 7b and the counter electrode 4 in close contact with the current collector 7a, the current collector 7b is placed in the outer cup 1, and the counter electrode 4 is placed in the outer can 3 The outer cup 1 and the outer can 3 were put together, and further, an insulating gasket 6 was interposed between the outer cup 1 and the outer can 3, and both peripheral portions were caulked and sealed.

基材、負極材料の物性等は以下の方法により測定した。測定結果・評価結果を表１に示した。
〔ラマン分光〕
負極材料等のラマン分光によるＲ値は、ラマン分光分析器［NR-1100:日本分光（株）製］を用い、励起光は波長５１４．５ｎｍのアルゴンレーザーで、照射面積は３０μｍφで分析し、Ｄバンド１３６０ｃｍ−１ピークの強度（ＩＤ）、Ｇバンド１５８０ｃｍ−１のピーク強度（ＩＧ）を測定した。そして強度比ＩＤ／ＩＧをＲ値としたことは前述した。 The physical properties of the base material and the negative electrode material were measured by the following methods. The measurement results and evaluation results are shown in Table 1.
[Raman spectroscopy]
The R value of the negative electrode material or the like by Raman spectroscopy was analyzed using a Raman spectrometer [NR-1100: manufactured by JASCO Corporation], the excitation light was analyzed with an argon laser having a wavelength of 514.5 nm, and the irradiation area was 30 μmφ. D band 1360 cm -1 peak intensity (ID), to measure the peak intensity of G-band 1580cm -1 (IG). And it was mentioned above that intensity ratio ID / IG was made into R value.

［基材のＸ線回折］
ＣｕＫα線をＸ線源、高純度シリコンを標準物質に使用して、基材等に対し（００２）回折ピークを測定し、そのピーク位置およびその半値幅から、それぞれｄ００２、Ｌｃを算出した。算出方法は学振法（日本学術振興会第１１７委員会が定めた測定法）に従うものであり、具体的には「炭素繊維」（大谷杉郎著、近代編集社、昭和６１年３月発行）の７３３〜７４２頁などに記載されている方法に拠ったことは前述した。 [X-ray diffraction of substrate]
Using a CuKα ray as an X-ray source and high-purity silicon as a standard material, a (002) diffraction peak was measured on a substrate or the like, and d 002 and Lc were calculated from the peak position and half width thereof, respectively. The calculation method follows the Japan Science and Technology Act (measurement method defined by the 117th Committee of the Japan Society for the Promotion of Science). Specifically, “Carbon Fiber” (written by Suguro Otani, Modern Editorial Company, published in March 1986) As described above, it was based on the method described in pp. 733-742.

［負極のＸ線回折］
負極を２５０ＭＰａでプレスし、打ち抜いた直径１５．５ｍｍの円柱を試料とした。
ＣｕＫα線をＸ線源、高純度シリコンを標準物質に使用して、負極の（００４）面のピーク強度（Ｉ００４）と（１１０）面のピーク強度（Ｉ１１０）を測定し、強度比ＲをＩ００４／Ｉ１１０で算出し、配向度とした。 [X-ray diffraction of negative electrode]
The negative electrode was pressed at 250 MPa, and a punched cylinder having a diameter of 15.5 mm was used as a sample.
CuKα line X-ray source, using a high-purity silicon as a standard substance, and measuring the peak intensity of the (004) surface of the negative electrode (I 004) and (110) plane peak intensity (I 110), the intensity ratio R Was calculated as I 004 / I 110 and used as the degree of orientation.

〔粒子径等〕
基材等の平均粒子径はレーザー回折式粒度分布計により測定した粒度分布の累積度数が体積百分率で５０％となる粒子径とした。
負極材料等の比表面積は、窒素ガス吸着によるＢＥＴ法により求めた。
負極材料等のタップ密度は、１５０ｃｍ３の容器に試料を充填した後、３００回タップした後の体積と質量より求めた。
負極材料等の層厚は、マイクロメーターの計測により求めた。 [Particle size, etc.]
The average particle size of the substrate and the like was a particle size at which the cumulative frequency of the particle size distribution measured by a laser diffraction particle size distribution meter was 50% by volume.
The specific surface area of the negative electrode material or the like was determined by the BET method using nitrogen gas adsorption.
The tap density of the negative electrode material and the like was determined from the volume and mass after tapping 300 times after a sample was filled in a 150 cm 3 container.
The layer thickness of the negative electrode material and the like was determined by measurement with a micrometer.

〔充放電試験〕
前記のように作製された評価電池について、２５℃の温度で下記のような充放電試験を行い、放電容量を測定し初回充放電ロス、２Ｃ放電率を計算した。評価結果を表１に示した。 (Charge / discharge test)
The evaluation battery produced as described above was subjected to the following charge / discharge test at a temperature of 25 ° C., the discharge capacity was measured, and the initial charge / discharge loss and 2C discharge rate were calculated. The evaluation results are shown in Table 1.

回路電圧が０ｍＶに達するまで０．９ｍＡの定電流充電を行った後、回路電圧が０ｍＶに達したら定電圧充電に切替え、さらに電流値が２０μＡになるまで充電を続けた。その間の通電量から充電容量（第一サイクルの充電容量）を求めた。その後、１２０分間休止した。次に０．９ｍＡの電流値で、回路電圧が１．５Ｖに達するまで定電流放電を行い、この間の通電量から放電容量（第一サイクルの放電容量）を求めた。次式（１）から初回充放電ロスを計算した。
次いで、充電電流を０．５Ｃ、放電電流を２Ｃとして前記と同様に充放電を行い、放電容量（２Ｃ電流値における放電容量）を求めた。そして、次式（２）から２Ｃ放電率を計算した。なお、１Ｃとは、対象とする負極が満充電状態にあるとき、その電気量を１時間で放出するときの電流値、０．５Ｃは２時間で放出するときの電流値、２Ｃは３０分で放出するときの電流値を言う。
なお、この試験では、リチウムイオンを負極材料に吸蔵する過程を充電、負極材料からリチウムイオンが脱離する過程を放電とした。
初回充放電ロス＝第一サイクルの充電容量−第一サイクルの放電容量 （１）
２Ｃ放電率（％）＝２Ｃ電流値における放電容量／第一サイクルの放電容量
×１００ （２） After constant current charging of 0.9 mA until the circuit voltage reached 0 mV, switching to constant voltage charging was performed when the circuit voltage reached 0 mV, and charging was continued until the current value reached 20 μA. The charge capacity (charge capacity of the first cycle) was determined from the energization amount during that time. Then, it rested for 120 minutes. Next, constant current discharge was performed at a current value of 0.9 mA until the circuit voltage reached 1.5 V, and the discharge capacity (discharge capacity of the first cycle) was determined from the energization amount during this period. The initial charge / discharge loss was calculated from the following equation (1).
Next, charging and discharging were performed in the same manner as described above with a charging current of 0.5 C and a discharging current of 2 C, and the discharge capacity (discharge capacity at a 2 C current value) was obtained. And 2C discharge rate was computed from following formula (2). Note that 1C is a current value when the target negative electrode is fully charged, and the amount of electricity is discharged in 1 hour, 0.5C is a current value when discharged in 2 hours, and 2C is 30 minutes. The current value when discharging at.
In this test, the process of occluding lithium ions in the negative electrode material was charged, and the process of detaching lithium ions from the negative electrode material was discharge.
Initial charge / discharge loss = charge capacity of first cycle-discharge capacity of first cycle (1)
2C discharge rate (%) = discharge capacity at 2C current value / discharge capacity of the first cycle
× 100 (2)

（参考例２）
参考例１において、メカノケミカル処理の代わりに、粉砕し黒鉛化した基材を、コールタールピッチ［ＪＦＥケミカル（株）製、残炭率：６０％］にタール中油を混合して調整したコールタールピッチ混合液に分散させ、二軸加熱ニーダーを用いて１５０℃で１時間混練し、混練生成物を得た。その際、固形分比率が基材：コールタールピッチ＝９２：８になるように調整した。混練生成物を真空にしてタール中油等の溶媒を除去した。得られた混練生成物を１３００℃で３時間加熱し、コールタールピッチの炭化物が基材を被覆した負極材料を作製した。
前記負極材料を用い、参考例１と同様な方法と条件で、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 2)
In Reference Example 1, instead of the mechanochemical treatment, a ground and graphitized base material was prepared by mixing coal tar oil with coal tar pitch [manufactured by JFE Chemical Co., Ltd., residual carbon ratio: 60%]. The mixture was dispersed in the pitch mixture and kneaded at 150 ° C. for 1 hour using a biaxial heating kneader to obtain a kneaded product. At that time, the solid content ratio was adjusted to be base material: coal tar pitch = 92: 8. The kneaded product was evacuated to remove solvents such as tar oil. The obtained kneaded product was heated at 1300 ° C. for 3 hours to prepare a negative electrode material in which a carbide of coal tar pitch covered the base material.
Using the negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same methods and conditions as in Reference Example 1, and measurements and evaluations were performed under the same methods and conditions as in Reference Example 1. The results are shown in Table 1.

（参考例３）
参考例１において、基材とメソフェーズピッチとの比率を１００：３に変えてメカノケミカル処理する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 3)
In Reference Example 1, the negative electrode material, the negative electrode mixture, the negative electrode, and the evaluation battery were the same as in Reference Example 1, except that the mechanochemical treatment was performed by changing the ratio of the base material to the mesophase pitch to 100: 3. Fabrication was performed, and measurement and evaluation were performed under the same method and conditions as in Reference Example 1. The results are shown in Table 1.

（参考例４）
参考例１において、基材とメソフェーズピッチとの比率を１００：１０に変えてメカノケミカル処理する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 4)
In Reference Example 1, the negative electrode material, the negative electrode mixture, the negative electrode, and the evaluation battery were prepared in the same manner and under the same conditions as in Reference Example 1, except that the ratio of the base material to the mesophase pitch was changed to 100: 10. Fabrication was performed, and measurement and evaluation were performed under the same method and conditions as in Reference Example 1. The results are shown in Table 1.

（参考例５）
参考例１において、粉砕した基材の平均粒子径を１０μｍに変える以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 5)
In Reference Example 1, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared in the same manner and conditions as in Reference Example 1 except that the average particle size of the pulverized base material was changed to 10 μm. Measurements and evaluations were performed under the same methods and conditions. The results are shown in Table 1.

（参考例６）
参考例１において、粉砕した基材の平均粒子径を３μｍに変える以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 6)
In Reference Example 1, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared in the same manner and conditions as in Reference Example 1 except that the average particle size of the pulverized base material was changed to 3 μm. Measurements and evaluations were performed under the same methods and conditions. The results are shown in Table 1.

（参考例７）
参考例１において、粉砕した基材の平均粒子径を２５μｍに変える以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 7)
In Reference Example 1, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were produced in the same manner and under the same conditions as in Reference Example 1, except that the average particle size of the ground substrate was changed to 25 μm. Measurements and evaluations were performed under the same methods and conditions. The results are shown in Table 1.

（比較例１）
参考例１において、メカノケミカル処理を省略する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 1)
In Reference Example 1, except that the mechanochemical treatment is omitted, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery are prepared in the same manner and conditions as in Reference Example 1, and the same method and conditions as in Reference Example 1 are obtained. Then, measurement and evaluation were performed. The results are shown in Table 1.

（比較例２）
参考例１において、メソフェーズ小球体の焼成生成物の粉砕を省略する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。該負極材料の外観を示す走査型電子顕微鏡写真を図３に示した。 (Comparative Example 2)
In Reference Example 1, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were produced in the same manner and under the same conditions as in Reference Example 1, except that the pulverization of the mesophase spherule fired product was omitted. Measurements and evaluations were performed under the same methods and conditions. The results are shown in Table 1. A scanning electron micrograph showing the appearance of the negative electrode material is shown in FIG.

（比較例３）
フリーカーボン（ＱＩ）を０．５質量％含有するコールタールを、３５０℃で０．５時間加熱した後、さらに４５０℃で０．２時間加熱してメソフェーズカーボン小球体を生成させた。加熱後のコールタールから、タール重油（沸点：２００〜３００℃）を用いてピッチを抽出し、ピッチマトリックスから濾過により、メソフェーズカーボン小球体を分離した。得られた小球体をロータリーキルンを用い５００℃で焼成し、得られた焼成生成物を２００メッシュ（篩目：７５μｍ）の振動篩を用いて、粗粒（凝集体）を除去した。得られた粒度調整品を粉砕することなく、黒鉛るつぼに入れ、アルゴン雰囲気下、昇温速度１０００℃／時間で昇温し、３０００℃で３時間懸けて黒鉛化し、基材（平均粒子径２５μｍ）を得た。
前記基材を用い、メカノケミカル処理を省略する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 3)
Coal tar containing 0.5% by mass of free carbon (QI) was heated at 350 ° C. for 0.5 hour, and further heated at 450 ° C. for 0.2 hour to produce mesophase carbon microspheres. Pitch was extracted from coal tar after heating using tar heavy oil (boiling point: 200 to 300 ° C.), and mesophase carbon microspheres were separated from the pitch matrix by filtration. The obtained spherules were fired at 500 ° C. using a rotary kiln, and coarse particles (aggregates) were removed from the obtained fired product using a 200-mesh (sieve: 75 μm) vibrating sieve. The obtained particle size-adjusted product was put into a graphite crucible without pulverization, heated in an argon atmosphere at a heating rate of 1000 ° C./hour, graphitized at 3000 ° C. for 3 hours, and the base material (average particle size 25 μm) )
A negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same method and conditions as in Reference Example 1 except that the mechanochemical treatment was omitted using the base material. Measurement and evaluation were performed under conditions. The results are shown in Table 1.

（比較例４）
参考例１において、メソフェーズカーボン小球体の焼成後の粉砕品の代わりに、粉砕した鱗片状黒鉛（天然黒鉛、平均粒子径２５μｍ）を用いる以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 4)
In Reference Example 1, in place of the pulverized product after firing the mesophase carbon spherules, the same method and conditions as in Reference Example 1 were used except that pulverized scaly graphite (natural graphite, average particle size 25 μm) was used. A material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared, and measured and evaluated under the same methods and conditions as in Reference Example 1. The results are shown in Table 1.

（比較例５）
参考例１において、メソフェーズカーボン小球体の焼成後の粉砕品の代わりに、粉砕した鱗片状黒鉛（天然黒鉛、平均粒子径２５μｍ）を用い、メカノケミカル処理を省略する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 5)
In Reference Example 1, in place of the pulverized product after firing of mesophase carbon microspheres, pulverized scaly graphite (natural graphite, average particle diameter 25 μm) was used, and the mechanochemical treatment was omitted. The negative electrode material, the negative electrode mixture, the negative electrode, and the evaluation battery were prepared using various methods and conditions, and measured and evaluated using the same methods and conditions as in Reference Example 1. The results are shown in Table 1.

（比較例６）
参考例１において、メソフェーズカーボン小球体の焼成後の粉砕品の代わりに、粉砕した鱗片状黒鉛をさらに球状化加工したもの（平均粒子径１５μｍ）を用いる以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 6)
In Reference Example 1, in place of the pulverized product after firing of mesophase carbon spherules, the same method as in Reference Example 1 was used except that pulverized flaky graphite was further spheroidized (average particle diameter: 15 μm). Under the conditions, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared, and measurement and evaluation were performed in the same manner and conditions as in Reference Example 1. The results are shown in Table 1.

（比較例７）
参考例１において、メソフェーズカーボン小球体の焼成後の粉砕品の代わりに、粉砕した鱗片状黒鉛をさらに球状化加工したもの（平均粒子径１５μｍ）を用い、メカノケミカル処理を省略する以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 7)
In Reference Example 1, instead of using a pulverized product of mesophase carbon spherules after calcination, pulverized flaky graphite was further spheroidized (average particle size: 15 μm), and the mechanochemical treatment was omitted except for reference. A negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same methods and conditions as in Example 1. Measurements and evaluations were performed under the same methods and conditions as in Reference Example 1. The results are shown in Table 1.

（比較例８）
比較例３と同様に粉砕することなく黒鉛化物を得た。この黒鉛化物を粉砕した基材（平均粒子径１５μｍ）を用いて、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Comparative Example 8)
A graphitized product was obtained without pulverization in the same manner as in Comparative Example 3. A negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared in the same manner and under the same conditions as in Reference Example 1 using the base material (average particle size of 15 μm) obtained by pulverizing this graphitized material. Measurements and evaluations were performed using various methods and conditions. The results are shown in Table 1.

（参考例８）
参考例２において、粉砕し黒鉛化した基材を、コールタールピッチ［ＪＦＥケミカル（株）製、残炭率：６０％］（基材に対して３質量％）とアセチレンブラック〔電気化学工業（株）製〕（基材に対して２質量％）にタール中油を混合して調整したコールタールピッチ混合液に分散させ、二軸加熱ニーダーを用いて１５０℃で１時間混練し、混練生成物を得た以外は、参考例２と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例２と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 8)
In Reference Example 2, the ground and graphitized base material was prepared from coal tar pitch [manufactured by JFE Chemical Co., Ltd., residual carbon ratio: 60%] (3% by mass with respect to the base material) and acetylene black [electrochemical industry ( Co., Ltd.] (2% by mass with respect to the base material) and dispersed in a coal tar pitch mixture prepared by mixing oil in tar, kneaded at 150 ° C. for 1 hour using a biaxial heating kneader, and kneaded product A negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same methods and conditions as in Reference Example 2 except that the measurement and evaluation were performed under the same methods and conditions as in Reference Example 2. . The results are shown in Table 1.

（実施例９）
参考例２において、粉砕し黒鉛化した基材を、コールタールピッチ［ＪＦＥケミカル（株）製、残炭率：６０％］（基材に対して３質量％）と気相成長炭素繊維〔ＶＧＣＦ、昭和電工（株）製〕（基材に対して２質量％）にタール中油を混合して調整したコールタールピッチ混合液に分散させ、二軸加熱ニーダーを用いて１５０℃で１時間混練し、混練生成物を得た以外は、参考例２と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例２と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 Example 9
In Reference Example 2, the ground and graphitized base material was made of coal tar pitch [manufactured by JFE Chemical Co., Ltd., residual carbon ratio: 60%] (3% by mass with respect to the base material) and vapor grown carbon fiber [VGCF , Manufactured by Showa Denko Co., Ltd.] (2% by mass with respect to the base material) and dispersed in a coal tar pitch mixture prepared by mixing oil in tar and kneaded at 150 ° C. for 1 hour using a biaxial heating kneader. A negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared in the same manner and conditions as in Reference Example 2 except that a kneaded product was obtained. Evaluation was performed. The results are shown in Table 1.

（参考例１０）
参考例１の粉砕し黒鉛化した基材を石英管に封入し、ヒーターで加熱して９００℃に保持した。石英管内に窒素ガスでバブリングしたベンゼンを２時間流通して基材にベンゼンを蒸着させた。前記蒸着生成物を用いて、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 10)
The ground and graphitized base material of Reference Example 1 was enclosed in a quartz tube, heated with a heater, and maintained at 900 ° C. Benzene bubbled with nitrogen gas was passed through the quartz tube for 2 hours to deposit benzene on the substrate. Using the vapor deposition product, a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same method and conditions as in Reference Example 1. Measurement and evaluation were performed under the same methods and conditions as in Reference Example 1. went. The results are shown in Table 1.

（参考例１１）
参考例１において、黒鉛化温度を３１００℃に変える以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 11)
In Reference Example 1, except that the graphitization temperature was changed to 3100 ° C., a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same method and conditions as in Reference Example 1, and the same method as in Reference Example 1 Measurement and evaluation were performed under the same conditions. The results are shown in Table 1.

（参考例１２）
参考例１において、黒鉛化温度を２８００℃に変える以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 12)
In Reference Example 1, except that the graphitization temperature was changed to 2800 ° C., a negative electrode material, a negative electrode mixture, a negative electrode, and an evaluation battery were prepared under the same method and conditions as in Reference Example 1, and the same method as in Reference Example 1 Measurement and evaluation were performed under the same conditions. The results are shown in Table 1.

（参考例１３）
参考例１において、基材とメソフェーズピッチとの比率を１００：１に変えてメカノケミカル処理すること以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 13)
In Reference Example 1, the negative electrode material, the negative electrode mixture, the negative electrode, and the evaluation battery were the same as in Reference Example 1, except that the mechanochemical treatment was performed by changing the ratio of the base material to the mesophase pitch to 100: 1. Was measured and evaluated under the same method and conditions as in Reference Example 1. The results are shown in Table 1.

（参考例１４）
参考例１において、基材とメソフェーズピッチとの比率を１００：１５に変えてメカノケミカル処理すること以外は、参考例１と同様な方法と条件で、負極材料、負極合剤、負極、評価電池の作製を行い、参考例１と同様な方法と条件で、測定、評価を行った。結果を表１に示した。 (Reference Example 14)
In Reference Example 1, the negative electrode material, the negative electrode mixture, the negative electrode, and the evaluation battery were the same as in Reference Example 1 except that the mechanochemical treatment was performed by changing the ratio of the base material to the mesophase pitch to 100: 15. Was measured and evaluated under the same method and conditions as in Reference Example 1. The results are shown in Table 1.

参考例１と比較例１との対比から、基材としてメソフェーズカーボン小球体の粉砕品の黒鉛化物を用いた場合、最表層の炭素質の薄層が存在すると、評価電池の充放電ロス、２Ｃ放電率が優れることが明らかである。
参考例１と比較例２との対比から、基材としてメソフェーズカーボン小球体の焼成生成物を粉砕して黒鉛化した黒鉛化物を用いた場合、粉砕せずに黒鉛化した黒鉛化物を用いた場合に比べ、評価電池の２Ｃ放電率が優れることが明らかである。 From the comparison between Reference Example 1 and Comparative Example 1, when a graphitized product of pulverized mesophase carbon spheres is used as a base material, if there is a thin carbonaceous layer as the outermost layer, the charge / discharge loss of the evaluation battery, 2C It is clear that the discharge rate is excellent.
From the comparison between Reference Example 1 and Comparative Example 2, when using a graphitized product obtained by pulverizing and graphitizing a fired product of mesophase carbon spherules as a base material, using a graphitized product without pulverizing It is clear that the 2C discharge rate of the evaluation battery is superior to

参考例１と比較例４との対比から、基材としてメソフェーズカーボン小球体の焼成生成物を粉砕して黒鉛化した黒鉛化物を用いた場合、鱗片状黒鉛を用いた場合に比べ、評価電池の初回充放電ロス、２Ｃ放電率が優れることが明らかである。
参考例１と比較例６との対比から、基材としてメソフェーズカーボン小球体の焼成生成物を粉砕して黒鉛化した黒鉛化物を用いた場合、鱗片状黒鉛の球状化品を用いた場合に比べ、評価電池の初回充放電ロス、２Ｃ放電率が優れることが明らかである。
参考例１と比較例８との対比から、基材としてメソフェーズカーボン小球体の焼成生成物を粉砕して黒鉛化した黒鉛化物を用いた場合、メソフェーズカーボン小球体を黒鉛化した後、粉砕して得た黒鉛化物を用いた場合に比べ、評価電池の初回充放電ロス、２Ｃ放電率が優れることが明らかである。 From the comparison between Reference Example 1 and Comparative Example 4, when a graphitized product obtained by pulverizing and graphitizing a fired product of mesophase carbon spherules as a base material was used, the evaluation battery was compared with the case of using scaly graphite. It is clear that the initial charge / discharge loss and the 2C discharge rate are excellent.
From the comparison between Reference Example 1 and Comparative Example 6, when a graphitized product obtained by pulverizing and graphitizing a fired product of mesophase carbon spherules as a base material is used, compared with a case where a spheroidized product of scaly graphite is used. It is clear that the initial charge / discharge loss and 2C discharge rate of the evaluation battery are excellent.
From the comparison between Reference Example 1 and Comparative Example 8, when a graphitized product obtained by pulverizing and graphitizing a fired product of mesophase carbon spheres as a base material was graphitized and then pulverized. It is clear that the initial charge / discharge loss and the 2C discharge rate of the evaluation battery are superior to the case of using the obtained graphitized material.

本発明のリチウムイオン二次電池用負極材料は、その電池特性を活かして、小型から大型の高性能リチウムイオン二次電池に搭載することができる。また、その特性を活かして、燃料電池セパレータ用の導電材などに使用することもできる。   The negative electrode material for a lithium ion secondary battery of the present invention can be mounted on a small to large high-performance lithium ion secondary battery by taking advantage of its battery characteristics. Moreover, it can also be used for the electrically conductive material for fuel cell separators, making use of the characteristic.

１ 外装カップ
２ 作用電極
３ 外装缶
４ 対極
５ 電解質溶液含浸セパレータ
６ 絶縁ガスケット
７ａ，７ｂ 集電体 DESCRIPTION OF SYMBOLS 1 Exterior cup 2 Working electrode 3 Exterior can 4 Counter electrode 5 Electrolyte solution impregnation separator 6 Insulation gasket 7a, 7b Current collector

Claims (5)

メソフェーズカーボン小球体の黒鉛化物を基材とし、前記基材の表面の少なくとも一部に、前記基材の表面よりも結晶性の低い炭素質物の付着物を有するリチウムイオン二次電池用負極材料であって、前記黒鉛化物がメソフェーズカーボン小球体を粉砕した後、黒鉛化して得た黒鉛化物であって、
前記基材のＸ線回折による炭素網面層の格子面間隔ｄ００２が０．３３６５ｎｍ以下で、波長５１４．５ｎｍのアルゴンレーザーを用いたラマンスペクトルにおける１３６０ｃｍ−１のピーク強度と１５８０ｃｍ−１のピーク強度との強度比（ＲＡ）が０．０５〜０．３であり、かつ、前記負極材料の前記ラマンスペクトルにおける１３６０ｃｍ−１のピーク強度と１５８０ｃｍ−１のピーク強度との強度比（ＲＢ）が０．３以上であって、ＲＡ＜ＲＢであり、前記結晶性の低い炭素質物の付着物が、炭素繊維を含有することを特徴とするリチウムイオン二次電池用負極材料。 A negative electrode material for a lithium ion secondary battery having a graphitized material of mesophase carbon spherules and having a carbonaceous material deposit having lower crystallinity than the surface of the substrate on at least a part of the surface of the substrate. The graphitized product is obtained by pulverizing mesophase carbon spherules and then graphitized,
Lattice spacing d 002 is less than or equal 0.3365nm carbon net plane layer by X-ray diffraction of the substrate, the peak of the peak intensity and 1580 cm -1 in 1360 cm -1 in the Raman spectrum using argon laser having a wavelength of 514.5nm the intensity ratio of the intensity (R a) is 0.05 to 0.3, and the intensity ratio of the peak intensity of the peak intensity and 1580 cm -1 in 1360 cm -1 in the Raman spectrum of the negative electrode material (R B ) Is 0.3 or more, R A <R B , and the adherent of the carbonaceous material having low crystallinity contains carbon fiber, a negative electrode material for a lithium ion secondary battery, 請求項１に記載のリチウムイオン二次電池用負極材料を用いることを特徴とするリチウムイオン二次電池用負極。   A negative electrode for a lithium ion secondary battery, wherein the negative electrode material for a lithium ion secondary battery according to claim 1 is used. 請求項２に記載のリチウムイオン二次電池用負極を用いることを特徴とするリチウムイオン二次電池。   A lithium ion secondary battery using the negative electrode for a lithium ion secondary battery according to claim 2. メソフェーズカーボン小球体を粉砕する粉砕工程と、前記粉砕工程で得られたメソフェーズカーボン小球体の粉砕品を加熱する黒鉛化工程と、前記黒鉛化工程で得られたメソフェーズカーボン小球体の黒鉛化物の表面の少なくとも一部に炭素質材料および炭素繊維を付着させる付着工程と、前記付着工程で得られた炭素質材料が付着したメソフェーズカーボン小球体の黒鉛化物を加熱し、前記炭素質材料を炭化する炭化工程を有することを特徴とする、請求項１に記載のリチウムイオン二次電池用負極材料を製造する、リチウムイオン二次電池用負極材料の製造方法。   A pulverization step for pulverizing mesophase carbon spherules, a graphitization step for heating a pulverized product of mesophase carbon spherules obtained in the pulverization step, and a graphitized surface of the mesophase carbon spherules obtained in the graphitization step An attachment step of attaching a carbonaceous material and carbon fiber to at least a part of the carbonaceous material, and heating the graphitized mesophase carbon microspheres attached with the carbonaceous material obtained in the attachment step to carbonize the carbonaceous material It has a process, The manufacturing method of the negative electrode material for lithium ion secondary batteries which manufactures the negative electrode material for lithium ion secondary batteries of Claim 1 characterized by the above-mentioned. 前記付着工程が、液相法によることを特徴とする、請求項４に記載のリチウムイオン二次電池用負極材料の製造方法。   The method for producing a negative electrode material for a lithium ion secondary battery according to claim 4, wherein the attaching step is performed by a liquid phase method.
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