JP2014029848A - Composite particle for lithium ion secondary battery negative electrode, method for producing the same, negative electrode for lithium ion secondary battery, and lithium ion secondary battery - Google Patents

Composite particle for lithium ion secondary battery negative electrode, method for producing the same, negative electrode for lithium ion secondary battery, and lithium ion secondary battery Download PDF

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JP2014029848A
JP2014029848A JP2013133845A JP2013133845A JP2014029848A JP 2014029848 A JP2014029848 A JP 2014029848A JP 2013133845 A JP2013133845 A JP 2013133845A JP 2013133845 A JP2013133845 A JP 2013133845A JP 2014029848 A JP2014029848 A JP 2014029848A
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JP5941437B2 (en
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Kunihiko Eguchi
邦彦 江口
Yasushi Madokoro
靖 間所
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JFE Chemical Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a composite particle for a lithium ion secondary battery negative electrode, with which a lithium ion secondary battery high in discharge capacity and furthermore having excellent initial charge/discharge efficiency and cycle characteristics can be obtained when the composite particle is used as a negative electrode material for a lithium ion secondary battery.SOLUTION: A composite particle for a lithium ion secondary battery negative electrode comprises a metal particle and/or a metal compound particle which can be alloyed with lithium, and a carbonaceous material (A). The carbonaceous material binds the metal particle and/or the metal compound particle, and a surface of a member having voids is covered with a carbonaceous material (B) and a graphite material.

Description

本発明は、リチウムイオン二次電池負極材料用複合粒子、リチウムイオン二次電池用負極及び／又はリチウムイオン二次電池に関する。   The present invention relates to a composite particle for a lithium ion secondary battery negative electrode material, a negative electrode for a lithium ion secondary battery and / or a lithium ion secondary battery.

リチウムイオン二次電池は、他の二次電池に比べて高電圧、高エネルギー密度という優れた特性を有するため、電子機器の電源として広く普及している。近年、電子機器の小型化あるいは高性能化が急速に進み、リチウムイオン二次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。   Lithium ion secondary batteries have excellent characteristics such as high voltage and high energy density compared to other secondary batteries, and are therefore widely used as power sources for electronic devices. In recent years, miniaturization or performance enhancement of electronic devices has rapidly progressed, and there is an increasing demand for higher energy density of lithium ion secondary batteries.

現在リチウムイオン二次電池は、正極にコバルト酸リチウム（ＬｉＣｏＯ２）、負極に黒鉛を用いたものが一般的である。しかし、黒鉛負極は充放電の可逆性に優れるものの、その放電容量は既に層間化合物ＬｉＣ６に相当する理論値３７２ｍＡｈ／ｇに近い値まで到達しており、さらなる高エネルギー密度化を達成するためには、黒鉛より放電容量の大きい負極材料を開発する必要がある。 Currently, lithium ion secondary batteries generally use lithium cobalt oxide (LiCoO 2 ) for the positive electrode and graphite for the negative electrode. However, although the graphite negative electrode is excellent in reversibility of charge and discharge, its discharge capacity has already reached a value close to the theoretical value 372 mAh / g corresponding to the intercalation compound LiC 6 in order to achieve further higher energy density. Needs to develop a negative electrode material having a larger discharge capacity than graphite.

金属リチウムは負極材料として最高の放電容量を有するが、充電時にリチウムがデンドライト状に析出して負極が劣化し、充放電サイクルが短くなるという問題がある。また、デンドライト状に析出したリチウムがセパレータを貫通して正極に達し、短絡する可能性もある。   Although metallic lithium has the highest discharge capacity as a negative electrode material, there is a problem that lithium is deposited in a dendritic state during charging, the negative electrode is deteriorated, and the charge / discharge cycle is shortened. In addition, lithium deposited in a dendrite shape may penetrate the separator and reach the positive electrode, causing a short circuit.

そのため，金属リチウムに変わる負極材料として、リチウムと合金を形成する金属質物が検討されてきた。これらの合金負極は、金属リチウムには及ばないものの黒鉛を遥かに凌ぐ放電容量を有する。しかし、合金化に伴う体積膨張により活物質の粉化・剥離が発生し、未だ実用レベルのサイクル特性は得られていない。   Therefore, metallic materials that form an alloy with lithium have been studied as negative electrode materials that replace metallic lithium. These alloy negative electrodes have discharge capacities far surpassing that of graphite, although they do not reach metal lithium. However, active materials are pulverized and peeled off due to volume expansion accompanying alloying, and a practical level of cycle characteristics has not yet been obtained.

前述のような合金負極の欠点を改善するため、金属質物と、黒鉛質物及び／又は炭素質物とを複合化して、複合粒子とすることが検討されている。大別すると（１）金属質物、黒鉛質物、炭素質物前駆体を混合後、熱処理するもの（特許文献１）、（２）ＣＶＤ法を用いて金属質物に炭素質層を被覆するもの（特許文献２）及び（３）前記（２）にメカニカルアロイングを併用するもの（特許文献３）等である。   In order to improve the above-described defects of the alloy negative electrode, it has been studied to form a composite particle by combining a metal material with a graphite material and / or a carbonaceous material. When classified roughly, (1) Metal material, graphite material, carbonaceous material precursor is mixed and then heat-treated (Patent Document 1), (2) Metal material is coated with a carbonaceous layer using CVD (Patent Document) 2) and (3) The above (2) is used in combination with mechanical alloying (Patent Document 3).

しかしながら（１）〜（３）のいずれにおいても、金属質物の周囲に黒鉛質物や炭素質物を単に配するだけでは、充電時の金属質物の膨張を充分に緩和できないため、活物質の微粉化や剥離といった問題を解決するには至らず、実用レベルのサイクル特性を得られていないのが現状である。   However, in any of (1) to (3), the expansion of the metallic material during charging cannot be sufficiently eased by simply arranging a graphite or carbonaceous material around the metallic material. The present situation is that the problem of peeling has not been solved, and the practical cycle characteristics have not been obtained.

これに対して、このような問題を解決しようとするアプローチとして、複合粒子に適度な割合の空隙を形成し、合金形成時の金属の膨張を吸収することにより、充放電を繰り返した場合であっても、複合粒子の粉化や剥離等の構造破壊を防止しようとするものがある。   On the other hand, an approach to solve such a problem is a case where charge / discharge is repeated by forming a suitable proportion of voids in the composite particles and absorbing the expansion of the metal during alloy formation. However, some attempt to prevent structural destruction such as powdering and peeling of the composite particles.

例えば、特許文献４には、リチウムと合金化可能な金属、黒鉛質材料及び炭素質材料からなる金属−黒鉛系複合粒子において、前記金属−黒鉛系複合粒子の全質量に対する前記リチウムと合金化可能な金属の質量の割合が１質量％以上３０質量％未満、前記黒鉛質材料の質量の割合が３０〜９５質量％、前記炭素質材料の質量の割合が４〜５０質量％であり、かつ前記黒鉛質材料が繊維状黒鉛質材料と非繊維状黒鉛質材料を含み、前記黒鉛質材料の全質量に対する前記繊維状黒鉛質材料の質量の割合が５０質量％未満であり、さらに前記金属−黒鉛系複合粒子の空隙率（％）を（１−嵩密度／真密度）×１００で規定した場合、前記空隙率が２５〜８０％であることを特徴とする金属−黒鉛系複合粒子が記載されている。   For example, in Patent Document 4, in a metal-graphite composite particle made of a metal that can be alloyed with lithium, a graphite material, and a carbonaceous material, it can be alloyed with the lithium with respect to the total mass of the metal-graphite composite particle. The mass ratio of the metal is 1 mass% or more and less than 30 mass%, the mass ratio of the graphite material is 30 to 95 mass%, the mass ratio of the carbonaceous material is 4 to 50 mass%, and The graphite material includes a fibrous graphite material and a non-fibrous graphite material, the ratio of the mass of the fibrous graphite material to the total mass of the graphite material is less than 50% by mass, and the metal-graphite When the porosity (%) of the composite particles is defined by (1-bulk density / true density) × 100, the metal-graphite composite particles are described, wherein the porosity is 25 to 80%. ing.

また、例えば、特許文献５には、リチウムと合金化可能な金属粒子、平均粒子径が２〜５μｍで、アスペクト比が３以下である複数個の黒鉛質粒子、及び炭素質材料を含有し、前記金属粒子の平均粒子径が前記黒鉛質粒子の平均粒子径の１／２以下であることを特徴とする金属−黒鉛質系粒子が記載され、さらにこの金属−黒鉛質系粒子の空隙率（％）の値が２５〜８０％であることが好ましいことも記載されている。   Further, for example, Patent Document 5 contains metal particles that can be alloyed with lithium, a plurality of graphite particles having an average particle diameter of 2 to 5 μm and an aspect ratio of 3 or less, and a carbonaceous material, The metal-graphitic particles are characterized in that the average particle size of the metal particles is ½ or less of the average particle size of the graphite particles, and the porosity of the metal-graphitic particles ( %) Is preferably 25 to 80%.

また、例えば、特許文献６には、リチウムと合金化可能な金属、黒鉛質材料及び炭素質材料からなる複合粒子において、前記複合粒子が空隙を有し、かつ前記複合粒子の全空隙に対する、金属周辺の空隙の割合が２０％以上であることを特徴とする複合粒子が記載されている。   Further, for example, in Patent Document 6, in a composite particle composed of a metal that can be alloyed with lithium, a graphite material, and a carbonaceous material, the composite particle has voids, and the metal with respect to all voids of the composite particle The composite particles are characterized in that the ratio of the peripheral voids is 20% or more.

また、例えば、特許文献７には、外表皮と、該外表皮に内包された中空部と、該中空部内に配置するリチウムと合金化可能な金属及び導電材（炭素材料ａ）を有する内包部材を備え、前記外表皮が黒鉛と炭素材料ｂを有し、前記中空部における内包部材の充填率が１０〜９０％であ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が記載されている。特許文献７の実施例１、２に記載された負極材料は、炭素材料ａ／（炭素材料ａ＋炭素材料ｂ）の値が大きいため、黒鉛質材料が複合粒子から脱落することがあるほか、黒鉛質材料の反応性が高くなり、不可逆容量の増大（初期充放電効率の低下）を招くことがある。実施例３に記載された負極材料は炭素材料ａ／（炭素材料ａ＋炭素材料ｂ）の値が小さいため、金属と炭素質材料ａとの結着性が不足し、サイクル特性の改良効果が得られない可能性がある。   Further, for example, Patent Document 7 discloses an enclosing member having an outer skin, a hollow portion enclosed in the outer skin, and a metal and a conductive material (carbon material a) that can be alloyed with lithium disposed in the hollow portion. A negative electrode material for a lithium ion secondary battery is described, wherein the outer skin has graphite and a carbon material b, and the filling rate of the inclusion member in the hollow portion is 10 to 90%. . Since the negative electrode materials described in Examples 1 and 2 of Patent Document 7 have a large value of carbon material a / (carbon material a + carbon material b), the graphite material may fall off from the composite particles. The reactivity of the material may increase, resulting in an increase in irreversible capacity (decrease in initial charge / discharge efficiency). Since the negative electrode material described in Example 3 has a small value of carbon material a / (carbon material a + carbon material b), the binding property between the metal and the carbonaceous material a is insufficient, and the effect of improving cycle characteristics is obtained. It may not be possible.

特開平５−２８６７６３号公報Japanese Patent Laid-Open No. 5-286863 特開平１０−３２１２２６号公報Japanese Patent Laid-Open No. 10-32226 特開２００２−２１６７５１号公報Japanese Patent Laid-Open No. 2002-216751 特開２００６−２６９１１０号公報JP 2006-269110 A 特開２００６−２９４４７６号公報JP 2006-294476 A 特開２００５−１２３１７５号公報JP-A-2005-123175 特開２００７−２９４１９６号公報JP 2007-294196 A

本発明は、上記のような状況を鑑みてなされたものであり、リチウムイオン二次電池用負極材料として用いて、放電容量が高く、しかも優れた初期充放電効率及びサイクル特性を有するリチウムイオン二次電池を得ることができるリチウムイオン二次電池負極用複合粒子を提供することを目的とする。また、本発明は、その複合粒子を負極材料として用いるリチウムイオン二次電池用負極及び／又はその負極を用いるリチウムイオン二次電池を提供することも目的とする。   The present invention has been made in view of the above situation, and is used as a negative electrode material for a lithium ion secondary battery, and has a high discharge capacity and excellent initial charge / discharge efficiency and cycle characteristics. It aims at providing the composite particle for lithium ion secondary battery negative electrodes which can obtain a secondary battery. Another object of the present invention is to provide a negative electrode for a lithium ion secondary battery using the composite particles as a negative electrode material and / or a lithium ion secondary battery using the negative electrode.

上記目的は、下記（１）〜（８）によって達成される。
（１）リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）とからなり、前記金属粒子及び／又は金属化合物粒子を前記炭素質材料（Ａ）が結着し、かつ空隙を有する部材の表面を、炭素質材料（Ｂ）及び黒鉛質材料で被覆した複合粒子であって、
前記複合粒子中の前記金属粒子、前記金属化合物粒子、前記炭素質材料（Ａ）、前記炭素質材料（Ｂ）及び前記黒鉛質材料の含有率が、
金属粒子及び金属化合物粒子の合計：１質量％以上３０質量％未満、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：２〜５０質量％、かつ
黒鉛質材料：２０〜９７質量％であり、
前記炭素質材料（Ａ）及び前記炭素質材料（Ｂ）の合計に対する前記炭素質材料（Ａ）の割合が２０〜８０質量％であり、
前記複合粒子の空隙率が１０〜７０％であり、
前記複合粒子の外表面から前記複合粒子の粒子径の１／８の厚さよりも内側に、前記複合粒子の空隙率の７０％以上が偏析し、かつ前記金属粒子及び前記金属化合物粒子の７０％以上が偏析しているリチウムイオン二次電池負極用複合粒子。
（２）前記黒鉛質材料の少なくとも一部が黒鉛質繊維である、上記（１）に記載の複合粒子。
（３）上記（１）又は（２）に記載のリチウムイオン二次電池負極用複合粒子を負極材料として用いるリチウムイオン二次電池用負極。
（４）上記（３）に記載のリチウムイオン二次電池用負極を有するリチウムイオン二次電池。
（５）リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体とを混合し、造粒する造粒体製造工程と、
前記造粒体製造工程で得られる造粒体に、炭素質材料（Ｂ）の前駆体及び黒鉛質材料を付着させる付着工程と、
前記付着工程で得られる付着物を焼成する焼成工程と
を備える、
リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）とからなり、前記金属粒子及び／又は金属化合物粒子を前記炭素質材料が結着し、かつ空隙を有する部材の表面を、炭素質材料（Ｂ）及び黒鉛質材料で被覆したリチウムイオン二次電池負極用複合粒子の製造方法。
（６）前記複合粒子中の前記金属粒子、前記金属化合物粒子、前記炭素質材料（Ａ）、前記炭素質材料（Ｂ）及び前記黒鉛質材料の含有率（割合）が、
金属粒子及び金属化合物粒子の合計：１質量％以上３０質量％未満、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：２〜５０質量％、かつ
黒鉛質材料：２０〜９７質量％であり、
前記複合粒子の空隙率が１０〜７０％であり、
前記複合粒子の外表面から前記複合粒子の粒子径の１／８の厚さよりも内側に、前記複合粒子の空隙率の７０％以上が偏析し、かつ前記金属粒子及び前記金属化合物粒子の７０％以上が偏析している、上記（５）に記載の製造方法。
（７）前記黒鉛質材料の少なくとも一部が黒鉛質繊維である、上記（５）又は（６）に記載の製造方法。
（８）前記炭素質材料（Ａ）の前駆体の残炭率が前記炭素質材料（Ｂ）の前駆体の残炭率よりも小さい、上記（５）〜（７）のいずれか１項に記載の製造方法。 The object is achieved by the following (1) to (8).
(1) It consists of metal particles and / or metal compound particles that can be alloyed with lithium, and a carbonaceous material (A), and the carbonaceous material (A) binds the metal particles and / or metal compound particles. And the composite particle | grains which coat | covered the surface of the member which has a space | gap with carbonaceous material (B) and graphite material,
The content of the metal particles, the metal compound particles, the carbonaceous material (A), the carbonaceous material (B), and the graphite material in the composite particles is as follows:
Total of metal particles and metal compound particles: 1% by mass or more and less than 30% by mass,
The total of the carbonaceous material (A) and the carbonaceous material (B): 2 to 50% by mass, and the graphite material: 20 to 97% by mass,
The ratio of the carbonaceous material (A) to the total of the carbonaceous material (A) and the carbonaceous material (B) is 20 to 80% by mass,
The porosity of the composite particles is 10 to 70%,
70% or more of the porosity of the composite particles segregates from the outer surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles, and 70% of the metal particles and the metal compound particles The composite particle for lithium ion secondary battery negative electrodes in which the above is segregated.
(2) The composite particle according to (1), wherein at least a part of the graphite material is a graphite fiber.
(3) A negative electrode for a lithium ion secondary battery using the composite particles for a lithium ion secondary battery negative electrode as described in (1) or (2) above as a negative electrode material.
(4) The lithium ion secondary battery which has a negative electrode for lithium ion secondary batteries as described in said (3).
(5) A granule manufacturing process in which metal particles and / or metal compound particles that can be alloyed with lithium and a precursor of the carbonaceous material (A) are mixed and granulated;
An adhesion step of attaching a precursor of carbonaceous material (B) and a graphite material to the granule obtained in the granule production step;
A firing step of firing the deposit obtained in the attaching step,
A member comprising metal particles and / or metal compound particles that can be alloyed with lithium, and a carbonaceous material (A), wherein the carbonaceous material binds the metal particles and / or metal compound particles and has voids. Of the composite particles for a negative electrode of a lithium ion secondary battery whose surface is coated with a carbonaceous material (B) and a graphite material.
(6) The content rate (ratio) of the metal particles, the metal compound particles, the carbonaceous material (A), the carbonaceous material (B), and the graphite material in the composite particles is:
Total of metal particles and metal compound particles: 1% by mass or more and less than 30% by mass,
The total of the carbonaceous material (A) and the carbonaceous material (B): 2 to 50% by mass, and the graphite material: 20 to 97% by mass,
The porosity of the composite particles is 10 to 70%,
70% or more of the porosity of the composite particles segregates from the outer surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles, and 70% of the metal particles and the metal compound particles The manufacturing method according to (5) above, in which the above is segregated.
(7) The production method according to (5) or (6), wherein at least a part of the graphite material is a graphite fiber.
(8) In any one of the above (5) to (7), the remaining carbon ratio of the precursor of the carbonaceous material (A) is smaller than the residual carbon ratio of the precursor of the carbonaceous material (B). The manufacturing method as described.

本発明によれば、リチウムイオン二次電池用負極材料として用いて、放電容量が高く、優れた初期充放電効率及びサイクル特性を有するリチウムイオン二次電池が得られるリチウムイオン二次電池負極用複合粒子、その製造方法、リチウムイオン二次電池用負極及び／又はリチウムイオン二次電池が提供される。   ADVANTAGE OF THE INVENTION According to this invention, the composite for lithium ion secondary battery negative electrodes which can be used as a negative electrode material for lithium ion secondary batteries, and can obtain the lithium ion secondary battery with high discharge capacity and the outstanding initial charging / discharging efficiency and cycling characteristics Particles, a production method thereof, a negative electrode for a lithium ion secondary battery and / or a lithium ion secondary battery are provided.

実施例において充放電試験に用いるためのボタン型評価電池の構造を示す模式断面図である。It is a schematic cross section which shows the structure of the button type evaluation battery for using for a charging / discharging test in an Example. 本発明におけるリチウムイオン二次電池負極用複合粒子の構造を示す模式断面図である。It is a schematic cross section which shows the structure of the composite particle for lithium ion secondary battery negative electrodes in this invention.

１．複合粒子
（１）金属粒子、金属化合物粒子
（種類）
金属粒子は、リチウムと合金化可能な金属の粒子であれば特に限定されない。
リチウムと合金化可能な金属としては、具体的には、例えば、Ａｌ、Ｐｂ、Ｚｎ、Ｓｎ、Ｂｉ、Ｉｎ、Ｍｇ、Ｇａ、Ｃｄ、Ａｇ、Ｓｉ、Ｂ、Ａｕ、Ｐｔ、Ｐｄ、Ｓｂ、Ｇｅ、Ｎｉ等が挙げられ、中でも、Ｓｉ又はＳｎが好ましい。
また、金属はこれらの金属の合金であってもよく、さらに合金中に他の元素を含有していてもよい。
金属化合物粒子は、リチウムと合金化可能な金属化合物の粒子であれば特に限定されない。
リチウムと合金化可能な金属化合物としては、上記リチウムと合金化可能な金属の酸化物、窒化物、炭化物等が挙げられ、中でも酸化物を少なくとも一部に含むことが好ましい。 1. Composite particles
(1) Metal particles, metal compound particles (type)
The metal particles are not particularly limited as long as they are metal particles that can be alloyed with lithium.
Specific examples of the metal that can be alloyed with lithium include Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd, Sb, and Ge. , Ni, etc., among which Si or Sn is preferable.
The metal may be an alloy of these metals, and may further contain other elements in the alloy.
The metal compound particle is not particularly limited as long as it is a metal compound particle that can be alloyed with lithium.
Examples of the metal compound that can be alloyed with lithium include oxides, nitrides, carbides, and the like of the metal that can be alloyed with lithium. Among these, it is preferable that the oxide is contained at least in part.

（複合粒子中の含有量）
金属粒子及び金属化合物粒子の複合粒子中の含有率（質量割合）は、これらの合計で、１質量％以上３０質量％未満、好ましくは２〜２０質量％である。
金属粒子及び金属化合物粒子の含有率が１質量％未満では放電容量向上の効果が小さくなり、３０質量％以上ではサイクル特性の改良効果が小さくなる。
金属粒子及び金属化合物粒子の含有率が２〜２０質量％の範囲であると、高い放電容量が得られ、かつ、金属粒子及び金属化合物粒子の充電膨張に起因するサイクル特性の低下を抑えることができ、好ましい。 (Content in composite particles)
The total content (mass ratio) of the metal particles and metal compound particles in the composite particles is 1% by mass or more and less than 30% by mass, preferably 2 to 20% by mass.
When the content of the metal particles and metal compound particles is less than 1% by mass, the effect of improving the discharge capacity is small, and when the content is 30% by mass or more, the effect of improving the cycle characteristics is small.
When the content ratio of the metal particles and the metal compound particles is in the range of 2 to 20% by mass, a high discharge capacity can be obtained, and the deterioration of the cycle characteristics due to the charge expansion of the metal particles and the metal compound particles can be suppressed. It is possible and preferable.

（平均粒子径）
金属粒子及び金属化合物粒子の平均粒子径は、特に限定されないが、好ましくは１０μｍ以下、より好ましくは５μｍ以下、さらに好ましくは１μｍ以下である。金属粒子及び金属化合物粒子の平均粒子径が１０μｍを超えると、サイクル特性の改良効果が小さくなる。
なお、本発明において、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ものである。 (Average particle size)
The average particle diameter of the metal particles and the metal compound particles is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less. When the average particle diameter of the metal particles and the metal compound particles exceeds 10 μm, the effect of improving the cycle characteristics becomes small.
In the present invention, the average particle size is measured by a laser diffraction particle size distribution meter.

（形状）
金属粒子及び金属化合物粒子の形状は特に限定されず、例えば、粒状、球状、板状、鱗片状、糸状等のいずれであってもよい。
なお、形状が板状、鱗片状の場合の平均粒子径は、その粒子と同一体積の球状粒子の平均粒子径に換算した値とする。また、糸状の場合の平均粒子径は、その最長部の平均長さとする。 (shape)
The shape of the metal particles and the metal compound particles is not particularly limited, and may be any of granular, spherical, plate-like, scale-like, and thread-like shapes, for example.
The average particle diameter when the shape is plate-like or scale-like is a value converted to the average particle diameter of spherical particles having the same volume as the particles. Moreover, let the average particle diameter in the case of a thread form be the average length of the longest part.

（２）黒鉛質材料
（種類）
黒鉛質材料は、リチウムイオンを吸蔵・放出することができるものであれば特に限定されない。黒鉛質材料としては、例えば、天然黒鉛や、タール、ピッチ類を最終的に１５００℃以上で熱処理して得られる人造黒鉛のような、その一部又は全部が黒鉛質で形成されているものが挙げられる。黒鉛質材料は、また、例えば、易黒鉛化性炭素材料とよばれる石油系、石炭系のタールピッチ類を熱処理して重縮合させたメソフェーズ焼成体、メソフェーズ小球体、コークス類を１５００℃以上、好ましくは２８００〜３３００℃で黒鉛化処理して得ることができる。 (2) Graphite material (type)
The graphite material is not particularly limited as long as it can occlude and release lithium ions. Examples of the graphite material include natural graphite, artificial graphite obtained by finally heat-treating tars and pitches at 1500 ° C. or higher, and part or all of which is formed of graphite. Can be mentioned. The graphite material is, for example, a mesophase fired body, a mesophase spheroid formed by heat-treating a petroleum-based or coal-based tar pitch called a graphitizable carbon material, polycondensed, mesophase spherules, and coke at 1500 ° C. or higher. Preferably, it can be obtained by graphitizing at 2800-3300 ° C.

（形状）
黒鉛質材料の形状は、特に限定されず、例えば、球状、塊状、板状、鱗片状、繊維状等のいずれであってもよいが、鱗片状又は鱗片状に近い形状のものが好ましい。また、液相、気相、固相における各種化学的処理、熱処理、酸化処理、物理的処理等を施したものであってもよい。 (shape)
The shape of the graphite material is not particularly limited, and may be any of a spherical shape, a block shape, a plate shape, a scale shape, a fiber shape, and the like, but a shape having a scale shape or a shape close to a scale shape is preferable. Further, it may be subjected to various chemical treatments in the liquid phase, gas phase, and solid phase, heat treatment, oxidation treatment, physical treatment, and the like.

（平均粒子径）
黒鉛質材料の平均粒子径は、特に限定されないが、好ましくは１〜３０μｍ、より好ましくは２〜１０μｍである。黒鉛質材料の平均粒子径についても、前記と同様の測定方法によって計測する。 (Average particle size)
Although the average particle diameter of a graphite material is not specifically limited, Preferably it is 1-30 micrometers, More preferably, it is 2-10 micrometers. The average particle diameter of the graphite material is also measured by the same measurement method as described above.

（黒鉛質繊維）
黒鉛質材料は、その一部又は全部を黒鉛質繊維に代えてもよい。すなわち、黒鉛質材料（黒鉛質繊維以外のもの）及び黒鉛質繊維を併用してもよい。
黒鉛質繊維は導電性を有する繊維状の黒鉛であればよく、特に限定されない。繊維状のものを含有させることにより、サイクル特性が向上する。
黒鉛質繊維の好ましい形状は、平均繊維径１０〜１０００ｎｍ、平均繊維長１〜２０μｍであり、具体的には、カーボンナノチューブ、カーボンナノファイバー、気相成長炭素繊維等が例示される。
平均繊維径及び平均繊維長は、走査型電子顕微鏡を用い、その形状が観察できる倍率で撮影して、５０本程度の黒鉛質繊維の繊維径及び繊維長について計測し平均値を採用する。 (Graphite fiber)
Part or all of the graphite material may be replaced with graphite fibers. That is, a graphite material (other than the graphite fiber) and the graphite fiber may be used in combination.
The graphite fiber may be fibrous graphite having conductivity, and is not particularly limited. By including a fibrous material, cycle characteristics are improved.
The preferred shape of the graphite fiber is an average fiber diameter of 10 to 1000 nm and an average fiber length of 1 to 20 μm, and specific examples include carbon nanotubes, carbon nanofibers, and vapor grown carbon fibers.
The average fiber diameter and the average fiber length are taken with a scanning electron microscope at a magnification at which the shape can be observed, measured for the fiber diameter and fiber length of about 50 graphite fibers, and average values are adopted.

（黒鉛質繊維の併用）
黒鉛質材料（黒鉛質繊維以外のもの）及び黒鉛質繊維を併用する場合には、これらの含有量比は特に限定されないが、黒鉛質材料（黒鉛質繊維以外の黒鉛質材料＋黒鉛質繊維）のうち０．５〜２０質量％を黒鉛質繊維とすることが好ましい。黒鉛質材料中の黒鉛質繊維の割合（以下、単に「黒鉛質繊維の割合」という場合がある。）は、より好ましくは１〜１５質量％、更に好ましくは２〜１０質量％である。黒鉛質繊維の割合が２０質量％を超えると、黒鉛質繊維の配合によるサイクル特性の向上効果が飽和し経済的に無駄となるほか、集電体からの活物質（複合粒子からなる負極材料）の剥離といった問題を生じるおそれがある。 (Combination with graphite fiber)
When the graphite material (other than the graphite fiber) and the graphite fiber are used in combination, the content ratio is not particularly limited, but the graphite material (graphite material other than the graphite fiber + graphite fiber) Of these, 0.5 to 20% by mass is preferably made of graphitic fibers. The ratio of the graphite fiber in the graphite material (hereinafter sometimes simply referred to as “the ratio of the graphite fiber”) is more preferably 1 to 15% by mass, and further preferably 2 to 10% by mass. If the proportion of the graphite fiber exceeds 20% by mass, the effect of improving the cycle characteristics due to the blending of the graphite fiber is saturated and economically wasteful, and the active material from the current collector (anode material composed of composite particles) There is a risk of causing problems such as peeling.

（３）炭素質材料（Ａ）、炭素質材料（Ｂ）
（種類）
炭素質材料（Ａ）及び炭素質材料（Ｂ）は、同一の炭素質材料であってもよいし、異なる炭素質材料であってもよい。
炭素質材料は、炭素質材料及び／又は結晶性の低い黒鉛質材料が得られるものであれば、いかなる前駆体に由来してもよいが、残炭率の異なる２種以上の炭素質材料前駆体に由来するものであることが好ましい。なかでも炭素材料前駆体としては、タールピッチ類及び／又は樹脂類が好ましい。具体的には、タールピッチ類としては、コールタール、タール軽油、タール中油、タール重油、ナフタリン油、アントラセン油、コールタールピッチ、ピッチ油、メソフェーズピッチ、酸素架橋石油ピッチ、ヘビーオイル等が挙げられる。樹脂類としては、ポリエチレン、ポリプロピレン、ポリアクリル酸、ポリビニルアルコール等の熱可塑性樹脂、フェノール樹脂、フラン樹脂等の熱硬化性樹脂が例示される。これらの炭素材料前駆体を熱処理することにより炭素質材料を得ることができる。ここで、残炭率とは、ＪＩＳ Ｋ ２４２５：２００５（クレオソート油、加工タール及びタールピッチ試験方法）の１１（固定炭素分定量方法）に準拠し、８００℃に加熱し、実質的に全量が炭素化されたときの残分を言い、百分率で表す。 (3) Carbonaceous material (A), carbonaceous material (B)
(type)
The carbonaceous material (A) and the carbonaceous material (B) may be the same carbonaceous material or different carbonaceous materials.
The carbonaceous material may be derived from any precursor as long as a carbonaceous material and / or a graphitic material having low crystallinity is obtained, but two or more types of carbonaceous material precursors having different residual carbon ratios. It is preferably derived from the body. Of these, tar pitches and / or resins are preferred as the carbon material precursor. Specifically, the tar pitches 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. . Examples of the resins include thermoplastic resins such as polyethylene, polypropylene, polyacrylic acid, and polyvinyl alcohol, and thermosetting resins such as phenol resins and furan resins. A carbonaceous material can be obtained by heat-treating these carbon material precursors. Here, the residual carbon ratio is based on 11 (fixed carbon content determination method) of JIS K 2425: 2005 (creosote oil, processed tar and tar pitch test method), heated to 800 ° C., and substantially the entire amount. Refers to the residue when is carbonized, expressed as a percentage.

樹脂類は相対的に多い空隙量を含有する炭素質材料の前駆体（つまり残炭率の相対的に低い炭素質材料前駆体）として、タールピッチ類は相対的に少ない空隙量を含有する炭素質材料の前駆体（つまり残炭率の相対的に高い炭素質材料前駆体）として用いることができる。   Resins are carbonaceous material precursors that contain relatively large amounts of voids (that is, carbonaceous material precursors that have a relatively low residual carbon ratio), and tar pitches are carbons that contain relatively small amounts of voids. It can be used as a precursor of a carbonaceous material (that is, a carbonaceous material precursor having a relatively high residual carbon ratio).

残炭率の相対的に低い炭素質材料前駆体は、熱処理後に多くの空隙を生じるので、主に複合粒子の中心部分の金属又は金属化合物粒子の周囲への空隙形成の役割を担う。残炭率の相対的に高い炭素質材料は、空隙の発生量が少なく、緻密な炭素質材料を形成するので、主に複合粒子の最表層の被覆による不可逆容量の低減（初期充放電効率の向上）や、黒鉛質材料を結着する役割を担う。   Since the carbonaceous material precursor having a relatively low residual carbon ratio generates many voids after the heat treatment, it mainly plays a role of void formation around the metal or metal compound particles in the central portion of the composite particles. The carbonaceous material with a relatively high residual carbon ratio has a small amount of voids and forms a dense carbonaceous material. Therefore, the irreversible capacity is reduced mainly by covering the outermost layer of the composite particles (the initial charge / discharge efficiency is improved). Improvement) and the role of binding graphite materials.

この配置が逆では、空隙の形成も、最表層の被覆も不完全なものになり、サイクル特性と初期充放電効率の改良効果が得られない可能性がある。前記炭素質物が一種類の炭素質材料前駆体のみに由来する場合には、後述する複合粒子の製造方法における造粒体製造工程と付着工程での炭素質材料前駆体の添加量を変えることにより、粒子内部と表面の空隙率を変化させることもできる。   If this arrangement is reversed, the formation of voids and the coating of the outermost layer become incomplete, and there is a possibility that the effect of improving cycle characteristics and initial charge / discharge efficiency cannot be obtained. When the carbonaceous material is derived from only one kind of carbonaceous material precursor, by changing the addition amount of the carbonaceous material precursor in the granule manufacturing process and the adhesion process in the composite particle manufacturing method described later In addition, the porosity of the inside and the surface of the particle can be changed.

（４）複合粒子全般
本発明の複合粒子は、リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料｛炭素質材料（Ａ）及び炭素質材料（Ｂ）をいう。｝と、黒鉛質材料とからなる複合粒子であって、さらに前記複合粒子が空隙を含有し、前記空隙と、前記金属粒子及び／又は金属化合物粒子とが、前記複合粒子の中心部分に偏在していることを特徴とする。
本発明の複合粒子では、上記空隙を有する部材は黒鉛質材料を含有しない。また、前記炭素質材料（Ａ）が、前記金属粒子及び／又は前記金属化合物粒子と前記黒鉛質材料とを結着しているが、結着とは、これらの少なくとも一部が接している状態を言う。
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計量に対する炭素質材料（Ａ）の割合は、２０〜８０質量％、特に３０〜７０質量％であることが好ましい。２０質量％未満の場合には、金属粒子及び/又は金属化合物粒子と炭素質材料（Ａ）との結着性が不足し、サイクル特性の改良効果が得られない可能性がある。また８０質量％超の場合には、黒鉛質材料が複合粒子から脱落することがあるほか、黒鉛質材料の反応性が高くなり、不可逆容量の増大（初期充放電効率の低下）を招くことがある。 (4) General composite particles The composite particles of the present invention are metal particles and / or metal compound particles that can be alloyed with lithium, carbonaceous materials {carbonaceous materials (A) and carbonaceous materials (B). } And a graphite material, wherein the composite particles further contain voids, and the voids and the metal particles and / or metal compound particles are unevenly distributed in the central portion of the composite particles. It is characterized by.
In the composite particle of the present invention, the member having the void does not contain a graphite material. Further, the carbonaceous material (A) binds the metal particles and / or the metal compound particles and the graphite material, and the binding is a state where at least a part of these is in contact with each other. Say.
The ratio of the carbonaceous material (A) to the total amount of the carbonaceous material (A) and the carbonaceous material (B) is preferably 20 to 80% by mass, particularly preferably 30 to 70% by mass. When the amount is less than 20% by mass, the binding property between the metal particles and / or metal compound particles and the carbonaceous material (A) is insufficient, and the effect of improving the cycle characteristics may not be obtained. If it exceeds 80% by mass, the graphite material may fall off from the composite particles, and the reactivity of the graphite material may increase, resulting in an increase in irreversible capacity (decrease in initial charge / discharge efficiency). is there.

本発明の複合粒子が優れたサイクル特性を有するのは、複合粒子の中心部分に空隙と金属又は金属化合物の粒子が偏在していることで、充放電時における金属又は金属化合物の膨張、収縮が空隙によって緩衝され、複合粒子の造粒構造の破壊が抑制されるためと考えられる。つまり、例え金属又は金属化合物質自体が粉化した場合でも、前記複合粒子全体としての粒子形状は維持されるため、複合粒子の粒子間の接触が保たれ、集電性が損なわれることはなく、サイクル特性の低下を抑制することが可能である。さらに、集電体からの活物質（複合粒子からなる負極材料）の剥離といった問題も生じない。   The composite particles of the present invention have excellent cycle characteristics because the voids and metal or metal compound particles are unevenly distributed in the central part of the composite particles, so that the metal or metal compound expands and contracts during charge and discharge. This is thought to be due to buffering by the voids and suppression of the destruction of the granulated structure of the composite particles. That is, even when the metal or metal compound itself is pulverized, the shape of the composite particles as a whole is maintained, so that the contact between the particles of the composite particles is maintained, and the current collecting property is not impaired. It is possible to suppress the deterioration of the cycle characteristics. Furthermore, the problem of peeling of the active material (negative electrode material made of composite particles) from the current collector does not occur.

複合粒子の平均粒子径は、３〜２５μｍが好ましく、５〜２０μｍが特に好ましい。３μｍ未満では初期充放電効率が低下し、２５μｍ超ではサイクル特性が低下する。複合粒子の平均粒子径も、前記と同様の測定方法によって計測したものである。   The average particle size of the composite particles is preferably 3 to 25 μm, particularly preferably 5 to 20 μm. If it is less than 3 μm, the initial charge / discharge efficiency decreases, and if it exceeds 25 μm, the cycle characteristics deteriorate. The average particle diameter of the composite particles is also measured by the same measurement method as described above.

複合粒子の比表面積は、ＢＥＴ法によって測定することができ、０．５〜２０ｍ２／ｇが好ましく、１〜１０ｍ２／ｇが特に好ましい。０．５ｍ２／ｇ未満の場合は充電性能が低下することによってサイクル特性が不足することがあり、２０ｍ２／ｇ超の場合は電解液の分解反応が過剰に進行し初期充放電効率が低下することがある。
ここでＢＥＴ比表面積は、ＪＩＳ Ｚ ８８３０：２００１（気体吸着による粉体（固体）の比表面積測定方法）に準拠して測定される。 The specific surface area of the composite particles may be measured by the BET method, preferably 0.5~20m 2 / g, 1~10m 2 / g is particularly preferred. If it is less than 0.5 m 2 / g, the cycle characteristics may be insufficient due to a decrease in charging performance, and if it exceeds 20 m 2 / g, the decomposition reaction of the electrolyte proceeds excessively and the initial charge / discharge efficiency decreases. There are things to do.
Here, the BET specific surface area is measured according to JIS Z 8830: 2001 (a method for measuring the specific surface area of a powder (solid) by gas adsorption).

さらに、前記金属又は金属化合物の周囲に存在する空隙は、前記金属又は金属化合物がリチウムと反応して形成される合金の体積以上の容積を有することが好ましい。金属又は金属化合物の周囲に存在する空隙の容積が、前記金属又は金属化合物がリチウムと反応して形成される合金の体積以下の場合には、サイクル特性の改良効果が小さくなることがある。   Furthermore, it is preferable that the space | gap which exists around the said metal or metal compound has a volume more than the volume of the alloy formed by the said metal or metal compound reacting with lithium. When the volume of voids around the metal or metal compound is equal to or less than the volume of the alloy formed by the reaction of the metal or metal compound with lithium, the effect of improving the cycle characteristics may be reduced.

本発明の複合粒子の主要構成成分の含有量は、複合粒子中で、金属粒子＋金属化合物粒子：１質量％以上３０質量％未満、黒鉛質材料：２０〜９７質量％、炭素質材料：２〜５０質量％である。
特に、複合粒子中で、金属粒子＋金属化合物粒子：２〜２０質量％、黒鉛質材料：３０〜８５質量％、炭素質材料：５〜４５質量％であることが好ましい。
それぞれがこの範囲にあると、高い放電容量が得られ、かつ、金属粒子及び金属化合物粒子の充電膨張に起因するサイクル特性の低下を抑え、電池諸特性のバランスが良い複合粒子となる。 The content of the main constituent component of the composite particles of the present invention is as follows: metal particles + metal compound particles: 1% by mass or more and less than 30% by mass, graphitic material: 20 to 97% by mass, carbonaceous material: 2 -50 mass%.
In particular, in the composite particles, it is preferable that metal particles + metal compound particles: 2 to 20% by mass, graphitic material: 30 to 85% by mass, and carbonaceous material: 5 to 45% by mass.
When each is in this range, a high discharge capacity is obtained, and deterioration of cycle characteristics due to charge expansion of metal particles and metal compound particles is suppressed, and composite particles having a good balance of various battery characteristics are obtained.

〈複合粒子の空隙率（体積％）〉
本発明の複合粒子の空隙率は、複合粒子全体に対する容積率（％）で１０〜７０％である。さらに、複合粒子の表面から、その粒子径の１／８の厚さよりも内側に、前記金属粒子及び前記金属化合物粒子の７０％以上が偏在し、かつ、複合粒子に含まれる空隙の容積率の７０％以上が偏在している中空構造からなる。ここで、粒子径の１／８の厚さよりも内側とは、例えば、複合粒子の粒子径が３２μｍの場合、該表面から４μｍよりも内側、すなわち中心から半径１２μｍよりも内部を意味し、また、全空隙及び全金属粒子の７０％以上がその半径１２μｍよりも内部に存在することを意味する。 <Porosity of composite particles (volume%)>
The porosity of the composite particles of the present invention is 10 to 70% in volume ratio (%) with respect to the entire composite particles. Furthermore, 70% or more of the metal particles and the metal compound particles are unevenly distributed from the surface of the composite particle to the inside of a thickness of 1/8 of the particle diameter, and the volume ratio of voids contained in the composite particle It consists of a hollow structure in which 70% or more is unevenly distributed. Here, the inner side than the thickness of 1/8 of the particle diameter means, for example, when the particle diameter of the composite particle is 32 μm, it means an inner side than the surface of 4 μm, that is, an inner side from the center of a radius of 12 μm, This means that 70% or more of all voids and all metal particles are present inside the radius of 12 μm.

金属粒子又は金属化合物粒子の周囲とは、これらがリチウムと反応して形成される膨張後の合金の体積に相当する領域を指し、金属がシリコンである場合には、シリコンの粒子径から約３倍に膨張した範囲の領域を意味する。   The periphery of the metal particles or metal compound particles refers to a region corresponding to the volume of the expanded alloy formed by reaction with lithium, and when the metal is silicon, it is about 3 from the particle diameter of silicon. It means the region in the range expanded twice.

複合粒子の空隙率は、複合粒子の断面を顕微鏡で観察し、空隙が占める面積率を複合粒子の面積率とする。５０個程度の複合粒子の断面について計測し平均値を採用する。   The porosity of the composite particles is obtained by observing the cross section of the composite particles with a microscope and taking the area ratio occupied by the voids as the area ratio of the composite particles. The average value is measured by measuring about 50 composite particles.

金属粒子及び金属化合物粒子が偏在する割合は、複合粒子の断面を観察し、金属粒子の分布をＳＥＭ−ＥＤＸ等で確認して、その断面の面積から求める。   The proportion of the metal particles and the metal compound particles unevenly distributed is determined from the area of the cross section by observing the cross section of the composite particle and confirming the distribution of the metal particles with SEM-EDX or the like.

また、複合粒子を構成する黒鉛質材料を黒鉛質繊維としてもよい。黒鉛質材料（黒鉛質繊維以外のもの）及び黒鉛質繊維を併用してもよいし、それぞれを単体で用いてもよい。黒鉛質繊維は金属又は金属化合物の粒子周囲に配置させることが好ましい。また、黒鉛質繊維は複合粒子の表面に起毛状に介在させることが好ましい。   Further, the graphite material constituting the composite particle may be a graphite fiber. Graphite materials (other than graphite fibers) and graphite fibers may be used in combination, or each may be used alone. The graphite fiber is preferably disposed around the metal or metal compound particles. Moreover, it is preferable to interpose the graphite fiber in a raised shape on the surface of the composite particle.

図２に本発明におけるリチウムイオン二次電池負極用複合粒子の模式断面図を示す。図２中、（ａ）はリン片状の黒鉛を用いた例、（ｂ）は粒状の黒鉛を用いた例、（ｃ）は（ａ）に黒鉛質繊維を含有する場合、（ｄ）は（ｂ）に黒鉛質繊維を含有する場合である。   FIG. 2 is a schematic cross-sectional view of the composite particle for a lithium ion secondary battery negative electrode in the present invention. In FIG. 2, (a) is an example using flake graphite, (b) is an example using granular graphite, (c) is a case where (a) contains graphitic fibers, (d) is This is a case where (b) contains a graphite fiber.

２．複合粒子の製造方法
本発明の複合粒子の製造方法について説明する。
本発明の複合粒子は、リチウムと合金化可能な金属粒子又は金属化合物粒子、黒鉛質材料及び炭素質材料からなる複合粒子において、その中心部分に空隙や金属及び／又は金属化合物が偏在するが黒鉛質材料は存在しない複合体を製造し得る方法であれば、いかなる方法によって製造されても差し支えない。
本発明の複合粒子の代表的な製造方法としては、例えば、金属粒子又は金属化合物粒子と、残炭率の相対的に低い炭素質材料（炭素質材料（Ａ））の前駆体の混合粒子を調製した後、前記混合粒子の表面に、残炭率の相対的に高い炭素質材料（炭素質材料（Ｂ））の前駆体及び黒鉛質材料を付着させ、これを熱処理することが挙げられる。熱処理によって炭素質材料前駆体が炭素質材料を形成するのと同時に、複合粒子の中心部分の炭素質材料は多くの空隙を有し、複合粒子の表層部分の炭素質材料は比較的緻密な構造とすることができる。
本発明の複合粒子は、複合粒子の外表面から該複合粒子の粒子径の１／８の厚さよりも内側に、空隙率の７０％以上、及び金属粒子及び金属化合物粒子の７０％以上が偏析した構造とすることが特徴であり、このような偏析を実現するためには、金属粒子又は金属化合物粒子と、残炭率の相対的に低い炭素質材料（炭素質材料（Ａ））の前駆体からなる混合粒子の大きさを、複合粒子の粒子径の１／８の厚さよりも内側の部分の大きさに相当するように設計することが重要である。
この製造方法において熱処理は、前記炭素材料前駆体が実質的に揮発物を含有しない状態にすることが可能な温度で行うことが好ましい。ただし、金属又は金属化合物の全てが炭素材料前駆体と反応して金属炭化物、たとえばＳｉＣ等に変化する温度にまで上げないことが必要である。Ｓｉを用いる場合、１５００℃以上では炭素とＳｉが反応してＳｉＣを形成するため、熱処理温度は１５００℃未満とする必要があり、特に８００〜１２００℃で熱処理することが好ましい。
なお、本発明の複合粒子は、単独で用いても、他の炭素質材料、黒鉛質材料、有機物、金属、金属化合物等と混合して用いてもよい。 2. Production method of composite particles The production method of the composite particles of the present invention will be described.
The composite particle of the present invention is a composite particle composed of metal particles or metal compound particles that can be alloyed with lithium, a graphite material, and a carbonaceous material, and voids, metals, and / or metal compounds are unevenly distributed in the central portion thereof. The quality material may be produced by any method as long as it can produce a composite that does not exist.
As a typical method for producing the composite particles of the present invention, for example, mixed particles of metal particles or metal compound particles and a precursor of a carbonaceous material (carbonaceous material (A)) having a relatively low residual carbon ratio are used. After the preparation, a precursor of a carbonaceous material (carbonaceous material (B)) having a relatively high residual carbon ratio and a graphitic material are attached to the surface of the mixed particles, and this is heat-treated. At the same time as the carbonaceous material precursor forms the carbonaceous material by heat treatment, the carbonaceous material in the central part of the composite particle has many voids, and the carbonaceous material in the surface layer part of the composite particle has a relatively dense structure It can be.
In the composite particles of the present invention, 70% or more of the porosity and 70% or more of the metal particles and the metal compound particles are segregated from the outer surface of the composite particles to the inner side of 1/8 of the particle diameter of the composite particles. In order to realize such segregation, a precursor of metal particles or metal compound particles and a carbonaceous material (carbonaceous material (A)) having a relatively low residual carbon ratio is used. It is important to design the size of the mixed particles composed of the body so as to correspond to the size of the inner portion of the composite particles, which is 1/8 the thickness of the particle diameter.
In this manufacturing method, the heat treatment is preferably performed at a temperature at which the carbon material precursor can be made substantially free of volatile substances. However, it is necessary not to raise the temperature at which all of the metal or metal compound reacts with the carbon material precursor and changes to a metal carbide such as SiC. When Si is used, carbon and Si react to form SiC at 1500 ° C. or higher, so that the heat treatment temperature needs to be lower than 1500 ° C., and it is particularly preferable to perform heat treatment at 800 to 1200 ° C.
The composite particles of the present invention may be used alone or mixed with other carbonaceous materials, graphitic materials, organic substances, metals, metal compounds and the like.

より具体的には、以下の工程によって本発明の複合粒子を製造することができる。
（１）造粒体製造工程
造粒体製造工程では、リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体とを混合し、造粒する。
混合及び造粒の方法は特に限定されないが、例えば、金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体とを加熱ニーダーに投入して、炭素質材料（Ａ）の前駆体の融点以上の温度（例えば１２０〜１８０℃）で３０分〜２時間混練し、ニーダーから取り出して冷却し、粉砕することによって造粒体（粉砕物）を形成することができる。このとき、できるだけ球状に粉砕することが好ましい。
金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体の溶液からなる分散液をスプレードライ方式によって散布し、同時に溶媒を乾燥除去する方法によっても、これらを混合及び造粒することができる。
金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体を混合し、混合物に圧縮力、せん断力を繰り返し付与できる装置にてメカノケミカル処理を行うことによって、機械的に造粒品（メカノケミカル処理体）を形成することもできる。メカノケミカル処理によって、金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体が一体化するのと同時に、造粒品を球状化することもできる。
ここで、リチウムと合金化可能な金属粒子及び／又は金属化合物粒子、炭素質材料（Ａ）は、それぞれ、本発明の複合粒子の項目で説明したものである。
なお、この造粒体の製造時には、黒鉛質材料を混合しない。 More specifically, the composite particles of the present invention can be produced by the following steps.
(1) Granule manufacturing process In a granule manufacturing process, the metal particle and / or metal compound particle which can be alloyed with lithium, and the precursor of carbonaceous material (A) are mixed and granulated.
The mixing and granulating method is not particularly limited. For example, the metal particles and / or the metal compound particles and the precursor of the carbonaceous material (A) are introduced into a heating kneader, so that the precursor of the carbonaceous material (A) is obtained. A granulated body (pulverized product) can be formed by kneading at a temperature equal to or higher than the melting point of the body (for example, 120 to 180 ° C.) for 30 minutes to 2 hours, taking out from the kneader, cooling, and pulverizing. At this time, it is preferable to grind as spherically as possible.
A dispersion liquid composed of a solution of metal particles and / or metal compound particles and a precursor of the carbonaceous material (A) is sprayed by a spray drying method, and these are mixed and granulated by a method of removing the solvent by drying at the same time. be able to.
Mechanically granulated by mixing metal particles and / or metal compound particles and a precursor of carbonaceous material (A) and performing mechanochemical treatment in an apparatus that can repeatedly apply compressive force and shear force to the mixture. A product (mechanochemically treated product) can also be formed. By the mechanochemical treatment, the metal particles and / or metal compound particles and the precursor of the carbonaceous material (A) are integrated, and at the same time, the granulated product can be spheroidized.
Here, the metal particles and / or metal compound particles that can be alloyed with lithium and the carbonaceous material (A) are those described in the item of composite particles of the present invention.
In addition, a graphite material is not mixed at the time of manufacturing this granulated body.

（２）付着工程
付着工程では、造粒工程で形成した造粒体の表面に、炭素質材料（Ｂ）の前駆体と、黒鉛質材料とを付着させる。
付着の方法は特に限定されないが、例えば、造粒体と、炭素質材料（Ｂ）の前駆体と、黒鉛質材料とを混合し、混合物に圧縮力、せん断力を繰り返し付与できる装置にてメカノケミカル処理を行うことによって付着体（メカノケミカル処理体）を形成することができる。このとき、造粒工程で形成した造粒体が過度に変形しないように、圧縮力、せん断力を調整する。
溶融状態あるいは溶液状態にある炭素質材料（Ｂ）の前駆体と、造粒体、黒鉛質材料とを混合し、造粒体の表面に炭素質材料（Ｂ）の前駆体と黒鉛質材料を付着させたのち、冷却あるいは乾燥（溶媒除去）して付着体を形成することもできる。
造粒体、黒鉛質材料、炭素質材料（Ｂ）の前駆体の溶液からなる分散液をスプレードライ方式によって散布し、同時に溶媒を乾燥除去する方法によっても、これらの付着体を形成することができる。この場合、炭素質材料（Ｂ）の前駆体の溶媒は、造粒体を構成する炭素質材料（Ａ）を溶解しないことが必要である。
造粒体、黒鉛質材料、溶融状態あるいは溶液状態にある炭素質材料（Ｂ）を転動式造粒機やロータリーキルンによって、加熱しながら転がす操作を与えることによっても、これらの付着体を形成することができる。なお、ロータリーキルンを用いる場合は、後述する焼成工程を同時に行うこともできる。 (2) Adhesion process In the adhesion process, the precursor of the carbonaceous material (B) and the graphite material are adhered to the surface of the granulated body formed in the granulation process.
The adhesion method is not particularly limited. For example, the mechano-mechanical apparatus is prepared by mixing a granulated material, a precursor of the carbonaceous material (B), and a graphite material, and repeatedly applying compressive force and shearing force to the mixture. By performing chemical treatment, an adherent (mechanochemically treated body) can be formed. At this time, the compression force and the shearing force are adjusted so that the granulated body formed in the granulation step does not deform excessively.
A precursor of carbonaceous material (B) in a molten state or a solution is mixed with a granulated body and a graphite material, and a precursor of carbonaceous material (B) and a graphite material are mixed on the surface of the granulated body. After adhering, the adhering body can also be formed by cooling or drying (solvent removal).
These adherents can also be formed by spraying a dispersion comprising a granulated body, a graphite material, and a precursor solution of the carbonaceous material (B) by a spray dry method and simultaneously removing the solvent by drying. it can. In this case, it is necessary that the solvent of the precursor of the carbonaceous material (B) does not dissolve the carbonaceous material (A) constituting the granulated body.
These adhering bodies are also formed by giving an operation of rolling a granulated body, a graphite material, a carbonaceous material (B) in a molten state or a solution state while heating it with a rolling granulator or a rotary kiln. be able to. In addition, when using a rotary kiln, the baking process mentioned later can also be performed simultaneously.

（３）焼成工程
焼成工程では、付着工程で得られた付着体を焼成し、本発明の複合粒子を製造する。
焼成の方法は特に限定されないが、例えば、窒素気流中等の非酸化雰囲気で８００〜１２００℃で焼成処理することによって複合粒子を製造することができる。 (3) Firing step In the firing step, the adherend obtained in the attaching step is fired to produce the composite particles of the present invention.
Although the method of baking is not specifically limited, For example, a composite particle can be manufactured by baking at 800-1200 degreeC by non-oxidizing atmosphere, such as in nitrogen stream.

（４）複合粒子
この製造方法によって製造される本発明の複合粒子は、
複合粒子中の金属粒子、金属化合物粒子、炭素質材料（Ａ）、炭素質材料（Ｂ）及び黒鉛質材料の含有率が、
金属粒子及び金属化合物粒子の合計：１質量％以上３０質量％未満、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：２〜５０質量％、かつ
黒鉛質材料：２０〜９７質量％、
好ましくは、金属粒子及び金属化合物粒子の合計：２〜２０質量％、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：５〜４５質量％、かつ
黒鉛質材料：３０〜８５質量％
であり、
前記炭素質材料（Ａ）及び前記炭素質材料（Ｂ）の合計量に対する前記炭素質材料（Ａ）の割合が２０〜８０質量％であり、
前記複合粒子の空隙率が１０〜７０％であり、
前記複合粒子の外表面から前記複合粒子の粒子径の１／８の厚さよりも内側に、前記複合粒子の空隙率の７０％以上が偏析し、かつ前記金属粒子及び前記金属化合物粒子の７０％以上が偏析しているものである。 (4) Composite particles The composite particles of the present invention produced by this production method are:
The content of the metal particles, metal compound particles, carbonaceous material (A), carbonaceous material (B) and graphitic material in the composite particles is
Total of metal particles and metal compound particles: 1% by mass or more and less than 30% by mass,
Total of carbonaceous material (A) and carbonaceous material (B): 2 to 50% by mass, and graphitic material: 20 to 97% by mass,
Preferably, the total of metal particles and metal compound particles: 2 to 20% by mass,
Total of carbonaceous material (A) and carbonaceous material (B): 5-45% by mass, and graphitic material: 30-85% by mass
And
The ratio of the carbonaceous material (A) to the total amount of the carbonaceous material (A) and the carbonaceous material (B) is 20 to 80% by mass,
The porosity of the composite particles is 10 to 70%,
70% or more of the porosity of the composite particles segregates from the outer surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles, and 70% of the metal particles and the metal compound particles The above is segregated.

３．リチウムイオン二次電池
本発明の複合粒子を電極材料として用いるリチウムイオン二次電池について説明する。リチウムイオン二次電池（以下、単に、二次電池とも記す）は、通常、電解液（非水電解質）、負極及び正極を主たる電池構成要素とし、これら要素が、例えば、二次電池缶内に封入されている。負極及び正極はそれぞれリチウムイオンの担持体として作用する。充電時には、リチウムイオンが負極に吸蔵され、放電時には負極からリチウムイオンが離脱する電池機構によっている。負極は、一般に、銅箔からなる集電材とバインダーによって結着された負極材料（活物質）から構成される。 3. Lithium ion secondary battery A lithium ion secondary battery using the composite particles of the present invention as an electrode material will be described. A lithium ion secondary battery (hereinafter also simply referred to as a secondary battery) usually has an electrolyte solution (non-aqueous electrolyte), a negative electrode, and a positive electrode as main battery components, and these elements are, for example, in a secondary battery can. It is enclosed. The negative electrode and the positive electrode each function as a lithium ion carrier. The battery mechanism is such that lithium ions are occluded in the negative electrode during charging and lithium ions are released from the negative electrode during discharging. The negative electrode is generally composed of a current collector made of copper foil and a negative electrode material (active material) bound by a binder.

本発明では、本発明の複合粒子をこの負極材料として用いること以外、特に限定されず、非水電解質、正極、セパレータ等の他の電池構成要素については一般的な二次電池の要素に準じる。   In the present invention, there is no particular limitation except that the composite particles of the present invention are used as the negative electrode material, and other battery components such as a nonaqueous electrolyte, a positive electrode, and a separator conform to the elements of a general secondary battery.

本発明では、上記のような本発明の複合粒子を単体、若しくは既知の負極活物質を混合して負極材料を調製する。
既知の負極活物質には各種公知の材料を用いることができるが、代表例には下記のものがある。
扁平状の粒子を複数、配向面が非平行となるように集合又は結合させてなり、粒子に細孔を有する黒鉛粒子。
球状のメソカーボン小球体の黒鉛化物、又は、メソカーボン小球体の粉砕物の黒鉛化物。天然黒鉛を球状化又は楕円体化してなる造粒物の黒鉛粒子間の空隙に炭素質物が充填してなる複合黒鉛粒子、又は、前記造粒物の表面を炭素質物が被覆してなる複合黒鉛粒子。コークス類を黒鉛化してなる人造黒鉛粒子。
バルクメソフェーズピッチを粉砕、酸化、炭化、黒鉛化してなる塊状の黒鉛粒子。 In the present invention, a negative electrode material is prepared by mixing the composite particles of the present invention as described above alone or a known negative electrode active material.
Various known materials can be used for the known negative electrode active material, and typical examples include the following.
Graphite particles having a plurality of flat particles aggregated or bonded so that their orientation planes are non-parallel, and having fine pores in the particles.
Graphite of spherical mesocarbon spherules or pulverized product of mesocarbon spherules. Composite graphite particles in which carbonaceous material is filled in the gaps between graphite particles of a granulated product obtained by spheroidizing or ellipsoidizing natural graphite, or composite graphite in which the surface of the granulated material is coated with a carbonaceous material particle. Artificial graphite particles made by graphitizing coke.
Bulk graphite particles obtained by pulverizing, oxidizing, carbonizing, and graphitizing bulk mesophase pitch.

既知の負極活物質は、異種の黒鉛材料、炭素質又は黒鉛質の繊維、非晶質ハードカーボン等の炭素材料、有機材料、無機材料、金属材料との混合物、複合物であってもよい。具体的には、界面活性剤、高分子等の有機化合物を付着又は被覆したものであってもよく、シリカ、アルミナ、チタニア等の金属酸化物の微粒子を付着又は埋設したものであってもよく、ケイ素、錫、コバルト、ニッケル、銅、酸化ケイ素、酸化錫、チタン酸リチウム等の金属又は金属化合物を、付着、埋設、複合、内包したものであってもよい。   The known negative electrode active material may be a heterogeneous graphite material, a carbonaceous or graphitic fiber, a carbon material such as amorphous hard carbon, an organic material, an inorganic material, a mixture with a metal material, or a composite. Specifically, a surfactant, a polymer or other organic compound may be attached or coated, or a metal oxide fine particle such as silica, alumina or titania may be attached or embedded. , Silicon, tin, cobalt, nickel, copper, silicon oxide, tin oxide, lithium titanate and other metals or metal compounds may be attached, embedded, combined, or encapsulated.

既知の負極活物質の平均粒子径は、前記複合粒子の平均粒子径よりも大きいことが特に好ましい。好ましい平均粒子径は、８〜３０μｍ、特に好ましくは１０〜２５μｍである。   The average particle diameter of the known negative electrode active material is particularly preferably larger than the average particle diameter of the composite particles. A preferable average particle diameter is 8-30 micrometers, Most preferably, it is 10-25 micrometers.

（１）負極
本発明のリチウムイオン二次電池用負極（以下、単に負極とも記す）の作製は、通常の負極の作製方法に準じて行うことができるが、化学的、電気化学的に安定な負極を得ることができる作製方法であれば何ら制限されない。 (1) Negative electrode The negative electrode for a lithium ion secondary battery of the present invention (hereinafter also simply referred to as a negative electrode) can be produced in accordance with a normal method for producing a negative electrode, but is chemically and electrochemically stable. There is no limitation as long as it is a production method capable of obtaining a negative electrode.

負極の作製には、前記負極材料に結合剤を加えた負極合剤を用いることができる。結合剤としては、電解質に対して化学的安定性、電気化学的安定性を有するものを用いることが好ましく、例えば、ポリフッ化ビニリデン、ポリテトラフルオロエチレン等のフッ素系樹脂、ポリエチレン、ポリビニルアルコール、スチレンブタジエンゴム、さらにはカルボキシメチルセルロース等が用いられる。これらを併用することもできる。結合剤は、通常、負極合剤の全量中１〜２０質量％の割合であることが好ましい。   For the production of the negative electrode, a negative electrode mixture obtained by adding a binder to the negative electrode material can be used. As the binder, those having chemical stability and electrochemical stability with respect to the electrolyte are preferably used. For example, fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, polyethylene, polyvinyl alcohol, and styrene. Butadiene rubber, carboxymethyl cellulose and the like are used. These can also be used together. Usually, the binder is preferably in a proportion of 1 to 20% by mass in the total amount of the negative electrode mixture.

負極の作製には、負極作製用の通常の溶媒であるＮ−メチルピロリドン、ジメチルホルムアミド、水、アルコール等を用いることができる。   For the production of the negative electrode, N-methylpyrrolidone, dimethylformamide, water, alcohol, etc., which are ordinary solvents for producing the negative electrode, can be used.

負極は、例えば、負極合剤を溶媒に分散させ、ペースト状の負極合剤を調製した後、前記負極合剤を集電体の片面又は両面に塗布し、乾燥して作製される。これにより、負極合剤層（活物質層）が均一かつ強固に集電体に接着した負極が得られる。
なお、負極合剤には、本発明以外の負極活物質や通常用いられる導電材、増粘剤などを添加しても良い。 The negative electrode is produced, for example, by dispersing a negative electrode mixture in a solvent to prepare a paste-like negative electrode mixture, and then applying the negative electrode mixture to one or both sides of a current collector and drying. Thereby, a negative electrode in which the negative electrode mixture layer (active material layer) is uniformly and firmly bonded to the current collector is obtained.
In addition, you may add negative electrode active materials other than this invention, the normally used electrically conductive material, a thickener, etc. to a negative mix.

より具体的には、例えば、前記負極材料の粒子、フッ素系樹脂粉末又はスチレンブタジエンゴムの水分散剤と溶媒を混合してスラリーとした後、公知の攪拌機、混合機、混練機、ニーダー等を用いて攪拌混合して、負極合剤ペーストを調製する。これを集電体に塗布、乾燥すれば、負極合剤層が均一かつ強固に集電体に接着する。負極合剤層の膜厚は１０〜２００μｍ、好ましくは３０〜１００μｍである。   More specifically, for example, after mixing the negative electrode material particles, fluorine resin powder or styrene butadiene rubber water dispersant and solvent into a slurry, a known stirrer, mixer, kneader, kneader or the like is used. The mixture is stirred and mixed to prepare a negative electrode mixture paste. When this is applied to the current collector and dried, the negative electrode mixture layer adheres uniformly and firmly to the current collector. The film thickness of the negative electrode mixture layer is 10 to 200 μm, preferably 30 to 100 μm.

また、負極合剤層は、前記負極材料の粒子と、ポリエチレン、ポリビニルアルコール等の樹脂粉末とを乾式混合し、金型内でホットプレス成形して作製することもできる。ただし、乾式混合では、十分な負極の強度を得るために多くの結合剤を必要とし、結合剤が過多の場合は、放電容量や急速充放電効率が低下することがある。   The negative electrode mixture layer can also be produced by dry-mixing the particles of the negative electrode material and resin powder such as polyethylene and polyvinyl alcohol and hot pressing in a mold. However, dry mixing requires a large amount of binder to obtain sufficient negative electrode strength, and if the binder is excessive, the discharge capacity and rapid charge / discharge efficiency may be reduced.

負極合剤層を形成した後、プレス加圧等の圧着を行うと、負極合剤層と集電体との接着強度をさらに高めることができる。   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 pressure bonding such as pressurization.

負極合剤層の密度は、負極の体積容量を高めることから、１．７０ｇ／ｃｍ３以上、特に１．７５ｇ／ｃｍ３以上であることが好ましい。 The density of the negative electrode mixture layer is preferably 1.70 g / cm 3 or more, particularly preferably 1.75 g / cm 3 or more in order to increase the volume capacity of the negative electrode.

負極に用いる集電体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等の網状物等が好ましい。集電体の材質としては、銅、ステンレス、ニッケル等が好ましい。集電体の厚みは、箔状の場合、好ましくは５〜２０μｍである。   The shape of the current collector used for the negative electrode is not particularly limited, but is preferably a foil, a mesh, a net-like material such as expanded metal, or the like. The material for the current collector is preferably copper, stainless steel, nickel or the like. When the current collector has a foil shape, the thickness is preferably 5 to 20 μm.

本発明のリチウムイオン二次電池は、前記負極を用いて形成される。
本発明の二次電池は、前記負極を用いること以外は特に限定されず、他の電池構成要素については、一般的な二次電池の要素に準じる。すなわち、電解液、負極及び正極を主たる電池構成要素とし、これら要素が、例えば電池缶内に封入されている。そして負極及び正極はそれぞれリチウムイオンの担持体として作用し、充電時には負極からリチウムイオンが離脱する。 The lithium ion secondary battery of the present invention is formed using the negative electrode.
The secondary battery of the present invention is not particularly limited except that the negative electrode is used, and other battery components conform to the elements of a general secondary battery. That is, an electrolytic solution, a negative electrode, and a positive electrode are used as main battery components, and these components are enclosed in, for example, a battery can. The negative electrode and the positive electrode each act as a lithium ion carrier, and lithium ions are released from the negative electrode during charging.

（２）正極
本発明の二次電池に使用される正極は、例えば正極材料と結合剤及び導電材よりなる正極合剤を集電体の表面に塗布することにより形成される。正極の材料（正極活物質）としては、リチウム化合物が用いられるが、充分な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い。例えば、リチウ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、その他のリチウム化合物、化学式ＭＸＭｏ６ＯＳ８−Ｙ（式中Ｘは０≦Ｘ≦４、Ｙは０≦Ｙ≦１の範囲の数値であり、Ｍは少なくとも一種の遷移金属元素である）で表されるシュブレル相化合物、活性炭、活性炭素繊維等を用いることができる。前記バナジウム酸化物はＶ２Ｏ５、Ｖ６Ｏ１３、Ｖ２Ｏ４、Ｖ３Ｏ８等である。 (2) Positive electrode The positive electrode used for the secondary battery of the present invention is formed by, for example, applying a positive electrode mixture comprising a positive electrode material, a binder and a conductive material to the surface of the current collector. As the positive electrode material (positive electrode active material), a lithium compound is used, but it is preferable to select a material that can occlude / desorb a sufficient amount of lithium. For example, lithium-containing transition metal oxide, transition metal chalcogenide, vanadium oxide, other lithium compounds, chemical formula M X Mo 6 OS 8-Y (where X is 0 ≦ X ≦ 4, Y is 0 ≦ Y ≦ 1) And the like, and M is at least one kind of transition metal element), and the like can be used. The vanadium oxide is V 2 O 5 , V 6 O 13 , V 2 O 4 , V 3 O 8 or the like.

前記リチウム含有遷移金属合酸化物は、リチウムと遷移金属とに複合酸化物であり、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も、２種類以上組合せて用いてもよい。リチウム含有遷移金属合酸化物は、具体的には、ＬｉＭ１ １−ＸＭ２ ＸＯ２（式中Ｘは０≦Ｘ≦１の範囲の数値であり、Ｍ１、Ｍ２は少なくとも一種の遷移金属元素である）又はＬｉＭ１ １−ＹＭ２ ＹＯ４（式中Ｙは０≦Ｙ≦１の範囲の数値であり、Ｍ１、Ｍ２は少なくとも一種の遷移金属元素である）で示される。 The lithium-containing transition metal composite 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. Complex oxides may be used alone or in combination of two or more. Specifically, the lithium-containing transition metal composite oxide is LiM 1 1-X M 2 X O 2 (wherein X is a numerical value in the range of 0 ≦ X ≦ 1, and M 1 and M 2 are at least one kind) Is a transition metal element) or LiM 1 1-Y M 2 Y O 4 (where Y is a numerical value in the range of 0 ≦ Y ≦ 1, and M 1 and M 2 are at least one transition metal element). Indicated.

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等であり、好ましいのはＣｏ、Ｍｎ、Ｃｒ、Ｔｉ、Ｖ、Ｆｅ、Ａｌ等である。好ましい具体例は、ＬｉＣｏＯ２、ＬｉＮｉＯ２、ＬｉＭｎＯ２、ＬｉＮｉ０．９Ｃｏ０．１Ｏ２、ＬｉＮｉ０．５Ｃｏ０．５Ｏ２等である。 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 examples are 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.

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、前記リチウム化合物を単独で使用してもよいし、２種類以上併用してもよい。また、正極中に炭酸リチウム等のアルカリ炭酸塩を添加することができる。   As the positive electrode active material, the lithium compound may be used alone or in combination of two or more. Moreover, alkali carbonates, such as lithium carbonate, can be added in a positive electrode.

正極は、例えば、前記リチウム化合物、結合剤、及び正極に導電性を付与するための導電材よりなる正極合剤を、集電体の片面又は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。導電材としては、黒鉛、カーボンブラック等の炭素材料が使用される。   The positive electrode is formed by, for example, applying a positive electrode mixture composed of the lithium compound, the binder, and a conductive material for imparting conductivity to the positive electrode to one or both sides of the current collector to form a positive electrode mixture layer. Produced. As the binder, the same one as that used for producing the negative electrode can be used. Carbon materials such as graphite and carbon black are used as the conductive material.

正極も負極と同様に、正極合剤を溶媒に分散させ、ペースト状にした正極合剤を集電体に塗布、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 formed by dispersing the positive electrode mixture in a solvent and applying the paste-like positive electrode mixture to a current collector and drying to form a positive electrode mixture layer. After that, 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.

集電体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等の網状等のものが好ましい。集電体の材質は、アルミニウム、ステンレス、ニッケル等である。その厚さは、箔状の場合、１０〜４０μｍが好適である。   The shape of the current collector is not particularly limited, but is preferably a foil shape, a mesh shape, a net shape such as expanded metal, or the like. The material of the current collector is aluminum, stainless steel, nickel or the like. In the case of a foil shape, the thickness is preferably 10 to 40 μm.

（３）非水電解質
本発明の二次電池に用いる非水電解質（電解液）は、通常の非水電解液に使用される電解質塩である。電解質塩としては、例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣｌＯ４、ＬｉＢ（Ｃ６Ｈ５）４、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、ＬｉＳｉＦ５等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い。 (3) Non-aqueous electrolyte The non-aqueous electrolyte (electrolytic solution) used for the secondary battery of the present invention is an electrolyte salt used for a normal non-aqueous electrolytic solution. Examples of the electrolyte salt include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB (C 6 H 5 ) 4 , 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 5 and other lithium salts can be used. In particular, LiPF 6 and LiBF 4 are preferable from the viewpoint of oxidation stability.

電解液の電解質塩濃度は０．１〜５ｍｏｌ／Ｌが好ましく、０．５〜３ｍｏｌ／Ｌがより好ましい。   The electrolyte salt concentration of the electrolytic solution is preferably 0.1 to 5 mol / L, and more preferably 0.5 to 3 mol / L.

非水電解質は液状としてもよく、固体、ゲル状等の高分子電解質としてもよい。前者の場合、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、後者の場合は、それぞれ高分子固体電解質電池、高分子ゲル電解質電池等の高分子電解質電池として構成される。   The non-aqueous electrolyte may be liquid, or may be a solid or gel polymer electrolyte. In the former case, the nonaqueous electrolyte battery is configured as a so-called lithium ion secondary battery, and in the latter case, the nonaqueous electrolyte battery is configured as a polymer electrolyte battery such as a polymer solid electrolyte battery or a polymer gel electrolyte battery.

非水電解質液を構成する溶媒としては、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等のカーボネート、１，１−又は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−ジオキソラン、アニソール、ジエチルエーテル等のエーテル、スルホラン、メチルスルホラン等のチオエーテル、アセトニトリル、クロロニトリル、プロピオニトリル等のニトリル、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等の非プロトン性有機溶媒等を用いることができる。   As a solvent constituting the nonaqueous electrolyte solution, carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate, 1,1- or 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2- Methyltetrahydrofuran, γ-butyrolactone, 1,3-dioxolane, 4-methyl-1,3-dioxolane, ethers such as anisole and diethyl ether, thioethers such as sulfolane and methylsulfolane, nitriles such as acetonitrile, chloronitrile and propionitrile , Trimethyl borate, tetramethyl silicate, nitromethane, dimethylformamide, N-methylpyrrolidone, ethyl acetate, trimethyl orthoformate, nitrobenzene, benzoyl chloride, benzoyl bromide, Tiger tetrahydrothiophene, dimethyl sulfoxide, 3-methyl-2-oxazolidone, ethylene glycol, may be used an aprotic organic solvent such as dimethyl sulfite, and the like.

前記高分子電解質を用いる場合には、可塑剤（非水電解液）でゲル化された高分子化合物をマトリックスとして使用することが好ましい。マトリクスを構成する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等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等のフッ素系高分子化合物等を単独又は混合して用いることができる。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等のフッ素系高分子化合物を用いることが特に好ましい。   When the polymer electrolyte is used, it is preferable to use a polymer compound gelled with a plasticizer (non-aqueous electrolyte) as a matrix. Examples of the polymer compound constituting the matrix include ether-based polymer compounds such as polyethylene oxide and its crosslinked products, polymethacrylate-based polymer compounds, polyacrylate-based polymer compounds, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene. Fluorine polymer compounds such as copolymers can be used alone or in combination. It is particularly preferable to use a fluorine-based polymer compound such as polyvinylidene fluoride or vinylidene fluoride-hexafluoropropylene copolymer.

前記高分子固体電解質又は高分子ゲル電解質には、可塑剤が配合されるが、可塑剤として前記の電解質塩や非水溶媒を使用することができる。高分子ゲル電解質の場合、可塑剤である非水電解液中の電解質塩濃度は０．１〜５ｍｏｌ／Ｌが好ましく、０．５〜２ｍｏｌ／Ｌがより好ましい。   A plasticizer is blended in the polymer solid electrolyte or polymer gel electrolyte, and the electrolyte salt or non-aqueous solvent can be used as the plasticizer. In the case of a polymer gel electrolyte, the concentration of the electrolyte salt in the non-aqueous electrolyte that is a plasticizer is preferably 0.1 to 5 mol / L, and more preferably 0.5 to 2 mol / L.

前記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、リチウム塩及び非水溶媒（可塑剤）を混合し、加熱して高分子化合物を溶融する方法、混合用有機溶媒に高分子化合物、リチウム塩、及び非水溶媒（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、リチウム塩及び非水溶媒（可塑剤）を混合し、混合物に紫外線、電子線、分子線等を照射して、重合性モノマーを重合させ、高分子化合物を得る方法等を挙げることができる。   The method for producing the polymer solid 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 to melt the polymer compound, mixing Method of evaporating organic solvent for mixing after dissolving polymer compound, lithium salt and non-aqueous solvent (plasticizer) in organic solvent for mixing, mixing polymerizable monomer, lithium salt and non-aqueous solvent (plasticizer) And a method of obtaining a polymer compound by irradiating the mixture with ultraviolet rays, an electron beam, a molecular beam or the like to polymerize a polymerizable monomer.

高分子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％を超えると機械的強度が弱くなり、製膜しにくくなる。   10-90 mass% is preferable, and, as for the ratio of the nonaqueous solvent (plasticizer) in a polymer 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 exceeds 90% by mass, the mechanical strength will be weak and film formation will be difficult.

（４）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。
セパレータの材質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等が挙げられる。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、ポリエチレン及びポリプロピレン製微多孔膜、又はこれらを複合した微多孔膜等である。 (4) Separator In the lithium ion secondary battery of the present invention, a separator can also be used.
Although the material of 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 film made of polyethylene and polypropylene, or a microporous film that combines these.

（５）リチウムイオン二次電池
本発明の二次電池は、前記負極、正極及び非水電解質を、例えば、負極、非水電解質、正極の順に積層し、電池の外装材内に収容することで作製される。
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。 (5) Lithium ion secondary battery In the secondary battery of the present invention, the negative electrode, the positive electrode, and the non-aqueous electrolyte are laminated in the order of, for example, the negative electrode, the non-aqueous electrolyte, and the positive electrode, and housed in the battery exterior material. Produced.
Further, a non-aqueous electrolyte may be disposed outside the negative electrode and the positive electrode.

本発明の二次電池の構造は特に限定されず、その形状、形態についても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等に応じて、円筒型、角型、コイン型、ボタン型等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、過充電等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。 The structure of the secondary battery of the present invention is not particularly limited, and the shape and form thereof are not particularly limited, and may be cylindrical, rectangular, depending on the application, mounted equipment, required charge / discharge capacity, and the like. A coin type, a button type, or the like can be arbitrarily selected. In order to obtain a sealed non-aqueous electrolyte battery with higher safety, it is preferable to include means for detecting an increase in the internal pressure of the battery and shutting off the current when an abnormality such as overcharge occurs.
In the case of a polymer electrolyte battery, a structure enclosed in a laminate film can also be used.

以下に、本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定されるものではない。   EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

［実施例１］
１．複合粒子の製造
（１）造粒工程
１．１）金属化合物粒子
シリコンを平均粒子径２００ｎｍに粉砕したのち、１２０℃の共沸硝酸溶液に３０分浸漬し、ろ過して、表面が酸化されたシリコン粒子を調製した。
また、シリコン粒子の１０％がＳｉＯ２に酸化されていることを確認した。
１．２）炭素質材料（Ａ）の前駆体
ポリプロピレン樹脂（残炭率２．２％）を準備した。
１．３）部材の製造
上記炭素質材料（Ａ）の前駆体 １００質量部と、上記金属化合物粒子 ２質量部とを、加熱ニーダーに投入して１５０℃で１時間混練し、取り出し、冷却後に、平均粒子径８μｍに粉砕して、造粒体を製造した。 [Example 1]
1. Production of composite particles (1) Granulation step 1.1) Metal compound particles After pulverizing silicon to an average particle size of 200 nm, it was immersed in an azeotropic nitric acid solution at 120 ° C. for 30 minutes and filtered to oxidize the surface. Silicon particles were prepared.
It was also confirmed that 10% of the silicon particles were oxidized to SiO 2 .
1.2) Precursor of carbonaceous material (A) A polypropylene resin (residual carbon ratio: 2.2%) was prepared.
1.3) Manufacture of members 100 parts by mass of the precursor of the carbonaceous material (A) and 2 parts by mass of the metal compound particles are put into a heating kneader, kneaded at 150 ° C. for 1 hour, taken out, and cooled. Then, it was pulverized to an average particle diameter of 8 μm to produce a granulated body.

（２）付着工程
２．１）炭素質材料（Ｂ）の前駆体
コールタールピッチの粉末（軟化点１１０℃、平均粒子径３μｍ、残炭率６０％）を準備した。
２．２）黒鉛質材料
天然黒鉛を粉砕して、平均粒子径３μｍ、比表面積１４．５ｍ２／ｇに調整した。
２．３）付着
上記造粒工程で製造した造粒物 １００質量部に、上記炭素質材料（Ｂ）の前駆体 ５質量部と、上記黒鉛質材料 ２０質量部とを混合し、混合物に圧縮力、せん断力を繰り返し付与できる装置にてメカノケミカル処理を行い、メカノケミカル処理物を得た。
２．４）メカノケミカル処理物
得られたメカノケミカル処理物は、ほぼ球状を呈しており、ポリプロピレン樹脂と金属化合物からなる粒子の表面に、コールタールピッチの粉末と黒鉛質材料が付着した複合物であった。 (2) Adhesion process 2.1) Precursor of carbonaceous material (B) A powder of coal tar pitch (softening point 110 ° C., average particle size 3 μm, residual carbon ratio 60%) was prepared.
2.2) Graphite material Natural graphite was pulverized to an average particle diameter of 3 μm and a specific surface area of 14.5 m 2 / g.
2.3) Adhesion 5 parts by mass of the precursor of the carbonaceous material (B) and 20 parts by mass of the graphitic material are mixed with 100 parts by mass of the granulated product produced in the granulation step, and compressed into a mixture. A mechanochemical treatment was performed with an apparatus capable of repeatedly applying force and shear force to obtain a mechanochemically treated product.
2.4) Mechanochemically treated product The obtained mechanochemically treated product has a substantially spherical shape, and is a composite in which coal tar pitch powder and a graphitic material adhere to the surface of particles made of polypropylene resin and a metal compound. Met.

（３）焼成工程
３．１）焼成
上記付着工程で得られたメカノケミカル処理物を窒素気流中１０００℃で焼成処理し、複合粒子を製造した。
３．２）複合粒子
製造した複合粒子は、平均粒子径１３μｍ、ＢＥＴ比表面積が４．８ｍ２／ｇであった。
なお、ポリプロピレン樹脂とコールタールピッチのみを上記比率で混合し、同様に１０００℃で焼成した場合の残炭率は５％であり、得られた複合粒子の構成は、金属化合物：黒鉛質粒子：炭素質材料＝２：２０：５．２、すなわち、全体を１００として、７．４：７３．５：１９．１であった。
また、製造した複合粒子を研磨して断面を観察した結果、粒子の中心部に空隙と金属化合物が偏在しており（それぞれ、中心部分空隙、中心部分金属という。）、平均粒子径の１／８、すなわち粒子の表面から１．６μｍよりも内側に、粒子内の平均空隙率５２％のうち４３％、すなわち全空隙の８３％が偏在していた。また、金属化合物の総含有量７．４％のうち６．７％、すなわち全金属化合物の９１％が偏在していた。
それぞれ、表１の「全空隙に占める中心部分空隙の体積割合（体積％）」、「全金属に占める中心部分金属の質量割合（質量％）」に示す。 (3) Firing step 3.1) Firing The mechanochemically processed product obtained in the attaching step was fired at 1000 ° C. in a nitrogen stream to produce composite particles.
3.2) Composite Particles The produced composite particles had an average particle diameter of 13 μm and a BET specific surface area of 4.8 m 2 / g.
In addition, only the polypropylene resin and coal tar pitch are mixed in the above ratio, and the residual carbon ratio when similarly fired at 1000 ° C. is 5%, and the composition of the obtained composite particles is composed of metal compound: graphite particles: Carbonaceous material = 2: 20: 5.2, that is, 7.4: 73.5: 19.1 with 100 as a whole.
Further, as a result of polishing the produced composite particles and observing the cross section, the voids and the metal compound are unevenly distributed in the center of the particles (referred to as the central portion void and the central portion metal, respectively), and 1 / of the average particle diameter. 8, that is, 43% of the average porosity of 52% in the particles, that is, 83% of the total voids was unevenly distributed on the inner side of 1.6 μm from the surface of the particles. Moreover, 6.7% of the total content of metal compounds was 6.7%, that is, 91% of all metal compounds were unevenly distributed.
They are shown in “Volume ratio (volume%) of central part occupying in all voids” and “Mass ratio (mass%) of central part occupying in all metals” in Table 1, respectively.

２．リチウムイオン二次電池の製造
（１）作用電極（負極）
製造した複合粒子 ９８質量部と、結合剤カルボキシメチルセルロース １質量部と、スチレンブタジエンゴム １質量部とを水に入れ、攪拌して負極合剤ペーストを調製した。
調製した負極合剤ペーストを、厚さ１６μｍの銅箔上に均一な厚さで塗布し、さらに真空中９０℃で分散媒の水を蒸発させて乾燥した。次に、この銅箔上に塗布された負極合剤をハンドプレスによって１２ｋＮ／ｃｍ２（１２０ＭＰａ）で加圧し、さらに直径１５．５ｍｍの円形状に打抜くことで、銅箔に密着した負極合剤層（厚み６０μｍ）を有する作用電極を作製した。
負極合剤層の密度は１．５ｇ／ｃｍ３であった。 2. Manufacture of lithium ion secondary battery (1) Working electrode (negative electrode)
98 parts by mass of the produced composite particles, 1 part by mass of a binder carboxymethyl cellulose, and 1 part by mass of styrene butadiene rubber were placed in water and stirred to prepare a negative electrode mixture paste.
The prepared negative electrode mixture paste was applied on a copper foil having a thickness of 16 μm to a uniform thickness, and further, water in a dispersion medium was evaporated at 90 ° C. in a vacuum to dry the paste. Next, the negative electrode mixture applied onto the copper foil was pressed with a hand press at 12 kN / cm 2 (120 MPa), and further punched into a circular shape with a diameter of 15.5 mm. A working electrode having an agent layer (thickness 60 μm) was prepared.
The density of the negative electrode mixture layer was 1.5 g / cm 3 .

（２）対極（正極）
リチウム金属箔を、ニッケルネットに押付け、直径１５．５ｍｍの円形状に打抜いて、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（厚さ０．５ｍｍ）からなる対極（正極）を作製した。 (2) Counter electrode (positive electrode)
A lithium metal foil is pressed onto a nickel net and punched into a circular shape with a diameter of 15.5 mm, and consists of a current collector made of nickel net and a lithium metal foil (thickness 0.5 mm) in close contact with the current collector. A counter electrode (positive electrode) was produced.

（３）電解液・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、六フッ化リン酸リチウム（ＬｉＰＦ６）を１ｍｏｌ／Ｌとなる濃度で溶解させ、非水電解液を調製した。
調製した非水電解液をポリプロピレン多孔質体（厚さ２０μｍ）に含浸させ、電解液が含浸されたセパレータを作製した。 (3) Electrolyte / Separator A nonaqueous electrolyte was prepared by dissolving lithium hexafluorophosphate (LiPF 6 ) at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate 33 vol% -methyl ethyl carbonate 67 vol%. .
The prepared non-aqueous electrolyte solution was impregnated into a polypropylene porous body (thickness 20 μm) to produce a separator impregnated with the electrolyte solution.

（４）リチウムイオン二次電池
ボタン型のリチウムイオン二次電池（図１参照）を製造した。以下、図１を参照しながら説明する。
４．１）電解液が含浸されたセパレータ５を、集電体７ｂに密着した作用電極２と、集電材７ａに密着した対極４との間に挟んで積層した。
４．２）その後、作用電極２を外装カップ１内に、対極４を外装缶３内に収容して、外装カップ１と外装缶３とを合わせ、さらに、外装カップ１と外装缶３との周縁部に絶縁ガスケット６を介在させ、両周縁部をかしめて密閉した。
これより、外装缶３の内面から順に、ニッケルネットからなる集電体７ａ、リチウム箔よりなる円筒状の対極（正極）４、電解液が含浸されたセパレータ５、負極合剤からなる円盤状の作用電極（負極）２及び銅箔からなる集電体７ｂが積層されたボタン型二次電池を製造した。
このボタン型二次電池は、実電池において、負極活物質として使用可能な黒鉛質物粒子を含有する作用電極２と、リチウム金属箔とからなる対極４とから構成される電池である。 (4) Lithium ion secondary battery A button-type lithium ion secondary battery (see FIG. 1) was produced. Hereinafter, a description will be given with reference to FIG.
4.1) The separator 5 impregnated with the electrolytic solution was sandwiched and laminated between the working electrode 2 in close contact with the current collector 7b and the counter electrode 4 in close contact with the current collector 7a.
4.2) Thereafter, the working electrode 2 is accommodated in the exterior cup 1, the counter electrode 4 is accommodated in the exterior can 3, the exterior cup 1 and the exterior can 3 are combined, and the exterior cup 1 and the exterior can 3 The insulating gasket 6 was interposed in the peripheral part, and both peripheral parts were crimped and sealed.
Thus, in order from the inner surface of the outer can 3, a current collector 7 a made of nickel net, a cylindrical counter electrode (positive electrode) 4 made of lithium foil, a separator 5 impregnated with an electrolytic solution, and a disk-like made of a negative electrode mixture A button-type secondary battery in which a working electrode (negative electrode) 2 and a current collector 7b made of copper foil were laminated was manufactured.
This button-type secondary battery is a battery composed of a working electrode 2 containing graphite particles that can be used as a negative electrode active material and a counter electrode 4 made of a lithium metal foil in an actual battery.

３．リチウムイオン二次電池の特性評価
製造したボタン型二次電池を評価電池として用いて、２５℃の温度下で下記のような充放電試験を行い、質量当たりの放電容量（ｍＡｈ／ｇ）、初期充放電効率（％）及びサイクル特性（％）を評価した。各特性の評価結果は、表１の各評価項目の欄に示す。 3. Characteristic Evaluation of Lithium Ion Secondary Battery Using the manufactured button type secondary battery as an evaluation battery, the following charge / discharge test was conducted at a temperature of 25 ° C., and the discharge capacity per unit mass (mAh / g) The charge / discharge efficiency (%) and cycle characteristics (%) were evaluated. The evaluation result of each characteristic is shown in the column of each evaluation item in Table 1.

（１）質量当たりの放電容量・初期充電効率
１．１）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、定電圧充電に切替え、電流値が２０μＡになるまで充電を続けた。その間の通電量から質量当たりの充電容量を求めた。その後、１２０分間休止した。次に０．９ｍＡの電流値で、回路電圧が１．５Ｖに達するまで定電流放電を行い、この間の通電量から質量当たりの放電容量（ｍＡｈ／ｇ）を求めた。これを第１サイクルとした。
１．２）上記第１サイクルにおける充電容量と放電容量から、次式により初期充放電効率（％）を計算した。
初期充放電効率（％）＝（放電容量／充電容量）×１００
なおこの試験では、リチウムイオンを負極材料に吸蔵する過程を充電、負極材料から離脱する過程を放電とした。 (1) Discharge capacity per mass / initial charging efficiency 1.1) After constant current charging of 0.9 mA until the circuit voltage reaches 0 mV, switching to constant voltage charging and charging until the current value reaches 20 μA Continued. The charging capacity per mass 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 per unit mass (mAh / g) was determined from the amount of current applied during this period. This was the first cycle.
1.2) From the charge capacity and discharge capacity in the first cycle, the initial charge / discharge efficiency (%) was calculated by the following equation.
Initial charge / discharge efficiency (%) = (discharge capacity / charge capacity) × 100
In this test, the process of occluding lithium ions in the negative electrode material was charged, and the process of detaching from the negative electrode material was discharged.

（２）サイクル特性
質量当たりの放電容量及び初期充電効率に関する特性を評価するために用いた評価電池とは別の評価電池を用いて、次の手順により電池特性の評価を行なった。
２．１）回路電圧が０ｍＶに達するまで４．０ｍＡの定電流充電を行った後、定電圧充電に切替え、電流値が２０μＡになるまで充電を続けた後、１２０分間休止した。
２．２）次に４．０ｍＡ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った。２０回充放電を繰返し、得られた質量当たりの放電容量から、次式を用いてサイクル特性を計算した。
サイクル特性（％）＝（第２０サイクルにおける放電容量／第１サイクルにおける放電容量）×１００ (2) Cycle characteristics The battery characteristics were evaluated by the following procedure using an evaluation battery different from the evaluation battery used for evaluating the characteristics regarding the discharge capacity per mass and the initial charge efficiency.
2.1) After carrying out constant current charging of 4.0 mA until the circuit voltage reached 0 mV, switching to constant voltage charging was continued until the current value reached 20 μA, and then rested for 120 minutes.
2.2) Next, constant current discharge was performed at a current value of 4.0 mA until the circuit voltage reached 1.5V. The charge / discharge was repeated 20 times, and the cycle characteristics were calculated from the obtained discharge capacity per mass using the following formula.
Cycle characteristics (%) = (discharge capacity in 20th cycle / discharge capacity in 1st cycle) × 100

［実施例２〜６、比較例１〜７］
１．複合粒子の製造
複合粒子中の黒鉛質材料、金属化合物粒子及び炭素質材料（炭素質材料（Ａ）＋炭素質材料（Ｂ））の含有率（割合）［単位：質量％］が表１に示すものとなるように、黒鉛質材料、金属化合物粒子、炭素質材料（Ａ）の前駆体及び炭素質材料（Ｂ）の前駆体の配合量を調整した点を除き、実施例１と同様にして複合粒子を製造した。
２．リチウムイオン二次電池の製造
製造した複合粒子を用いて、実施例１と同様にしてリチウムイオン二次電池（ボタン型二次電池）を製造した。
３．リチウムイオン二次電池の特性評価
製造したボタン型二次電池を評価電池として用いて、実施例１と同様にして充放電試験を行い、電池特性（放電容量、初期充放電効率及びサイクル特性）の評価を行った。評価結果を表１の該当欄に示す。 [Examples 2-6, Comparative Examples 1-7]
1. Production of Composite Particles Table 1 shows the content (ratio) [unit: mass%] of the graphite material, metal compound particles, and carbonaceous material (carbonaceous material (A) + carbonaceous material (B)) in the composite particle. As in Example 1, except that the blending amounts of the graphite material, the metal compound particles, the precursor of the carbonaceous material (A), and the precursor of the carbonaceous material (B) were adjusted. Thus, composite particles were manufactured.
2. Production of Lithium Ion Secondary Battery A lithium ion secondary battery (button type secondary battery) was produced in the same manner as in Example 1 using the produced composite particles.
3. Characteristic Evaluation of Lithium Ion Secondary Battery Using the manufactured button type secondary battery as an evaluation battery, a charge / discharge test was conducted in the same manner as in Example 1, and the battery characteristics (discharge capacity, initial charge / discharge efficiency and cycle characteristics) were Evaluation was performed. The evaluation results are shown in the corresponding column of Table 1.

［実施例７］
１．複合粒子の製造
（１）造粒工程
１．１）金属化合物粒子
シリコンを平均粒子径１００ｎｍに粉砕したものを調製した。
１．２）炭素質材料（Ａ）の前駆体
ポリアクリル酸樹脂（残炭率６％）を準備した。
１．３）部材の製造
上記炭素質材料（Ａ）の前駆体 ３０質量部、イオン交換水 ７０質量部と、上記金属化合物粒子 ２．６質量部とを混合して、スラリーを調製し、これをスプレードライヤーで噴霧すると同時に２００℃で加熱して溶媒を乾燥させて、平均粒子径１２μｍの真球状造粒体を製造した。
（２）付着工程
２．１）炭素質材料（Ｂ）の前駆体
コールタール（常温液状、残炭率２５％）を準備した。
２．２）黒鉛質材料
天然黒鉛を粉砕して、平均粒子径３μｍ、比表面積１４．５ｍ２／ｇに調整した。また、黒鉛質繊維（平均繊維径７０ｎｍ、平均繊維長５μｍの気相成長炭素繊維の黒鉛化物）を準備した。
２．３）付着
上記造粒工程で製造した造粒物 １００質量部を、円筒容器型の転動造粒機に投入し、回転撹拌しながら、上記炭素質材料（Ｂ）の前駆体 １５質量部を散布して３０分運転した。
引き続き、回転撹拌を続けながら、上記天然黒鉛 ２０質量部と、黒鉛質繊維 ２質量部とを投入し、さらに１時間運転した。
２．４）転動造粒処理物
得られた転動造粒処理物は、ほぼ球状を呈しており、ポリアクリル酸樹脂と金属化合物からなる造粒粒子の表面に、天然黒鉛及び黒鉛質繊維がコールタールによって付着した複合物であった。
（３）焼成工程
３．１）焼成
上記付着工程で得られた転動造粒処理物を窒素気流中１０００℃で焼成処理し、複合粒子を製造した。
３．２）複合粒子
製造した複合粒子は、平均粒子径１７μｍ、ＢＥＴ比表面積が４．９ｍ２／ｇであった。
なお、ポリアクリル酸樹脂及びコールタールのみを上記比率で混合し、同様に１０００℃で焼成した場合の残炭率は８．６％であり、得られた複合粒子の構成は、金属化合物：黒鉛質材料（天然黒鉛＋黒鉛質繊維）：炭素質材料＝８．２：２２：９．４［天然黒鉛：黒鉛質繊維＝２０：２］、すなわち、全体を１００として、１６．６：５８．５：２４．９［天然黒鉛：黒鉛質繊維＝５３．２：５．３］であった。
また、製造した複合粒子を研磨して断面を観察した結果、粒子の中心部に空隙と金属化合物が偏在しており（それぞれ、中心部分空隙、中心部分金属という。）、平均粒子径の１／８、すなわち粒子の表面から２．１μｍよりも内側に、粒子内の平均空隙率６０％のうち５１％、すなわち全空隙の８５％が偏在していた。また、金属化合物の総含有量１２．８％のうち１１．３％、すなわち全金属化合物の８８％が偏在していた。
黒鉛質繊維は、複合粒子の主に表面に起毛状に存在し、その一部は複合粒子内部の金属粒子周囲にも介在していた。
それぞれ、表１の「全空隙に占める中心部分空隙の体積割合（体積％）」、「全金属に占める中心部分金属の質量割合（質量％）」に示す。 [Example 7]
1. Manufacture of composite particles (1) Granulation step 1.1) Metal compound particles A material obtained by pulverizing silicon to an average particle size of 100 nm was prepared.
1.2) Precursor of carbonaceous material (A) A polyacrylic acid resin (residual carbon ratio 6%) was prepared.
1.3) Manufacture of member 30 mass parts of the precursor of the carbonaceous material (A), 70 mass parts of ion-exchanged water, and 2.6 mass parts of the metal compound particles are mixed to prepare a slurry. Was sprayed with a spray dryer and simultaneously heated at 200 ° C. to dry the solvent to produce a true spherical granule having an average particle size of 12 μm.
(2) Adhesion process 2.1) Precursor of carbonaceous material (B) Coal tar (liquid at normal temperature, residual carbon ratio 25%) was prepared.
2.2) Graphite material Natural graphite was pulverized to an average particle diameter of 3 μm and a specific surface area of 14.5 m 2 / g. Further, a graphite fiber (graphitized product of vapor grown carbon fiber having an average fiber diameter of 70 nm and an average fiber length of 5 μm) was prepared.
2.3) Adhesion 100 parts by mass of the granulated product produced in the above granulation step is put into a cylindrical container type rolling granulator, and the precursor of the carbonaceous material (B) is 15 masses while rotating and stirring. The part was sprayed and operated for 30 minutes.
Subsequently, 20 parts by mass of the natural graphite and 2 parts by mass of the graphite fiber were added while continuing the rotary stirring, and the operation was further continued for 1 hour.
2.4) Rolled granulated product The obtained rolled granulated product has a substantially spherical shape, and natural graphite and graphite fibers are formed on the surface of the granulated particles composed of a polyacrylic acid resin and a metal compound. Was a composite adhered by coal tar.
(3) Firing step 3.1) Firing The tumbling granulated product obtained in the adhering step was calcined at 1000 ° C. in a nitrogen stream to produce composite particles.
3.2) Composite Particles The produced composite particles had an average particle diameter of 17 μm and a BET specific surface area of 4.9 m 2 / g.
In addition, only the polyacrylic acid resin and coal tar were mixed in the above ratio, and similarly, the residual carbon ratio when calcined at 1000 ° C. was 8.6%. The composition of the obtained composite particles was composed of a metal compound: graphite Material (natural graphite + graphitic fiber): carbonaceous material = 8.2: 22: 9.4 [natural graphite: graphitic fiber = 20: 2], ie, 16.6: 58. 5: 24.9 [natural graphite: graphite fiber = 53.2: 5.3].
Further, as a result of polishing the produced composite particles and observing the cross section, the voids and the metal compound are unevenly distributed in the center of the particles (referred to as the central portion void and the central portion metal, respectively), and 1 / of the average particle diameter. 8, that is, 51% of the average porosity of 60% in the particles, that is, 85% of the total voids was unevenly distributed on the inner side of 2.1 μm from the surface of the particles. Further, 11.3% of the total metal compound content of 12.8%, that is, 88% of all metal compounds were unevenly distributed.
Graphite fibers existed mainly on the surface of the composite particles in a raised shape, and some of them were also present around the metal particles inside the composite particles.
They are shown in “Volume ratio (volume%) of central part occupying in all voids” and “Mass ratio (mass%) of central part occupying in all metals” in Table 1, respectively.

［実施例８、９、比較例８〜１１］
１．複合粒子の製造
複合粒子中の黒鉛質材料（天然黒鉛＋黒鉛質繊維）、金属粒子及び炭素質材料（炭素質材料（Ａ）＋炭素質材料（Ｂ））の含有率（割合）[単位：質量％］が表１に示すものとなるように、天然黒鉛、黒鉛質繊維、金属粒子、炭素質材料（Ａ）の前駆体及び炭素質材料（Ｂ）の前駆体の配合量を調整した点を除き、実施例７と同様にして複合粒子を製造した。
２．リチウムイオン二次電池の製造
製造した複合粒子を用いて、実施例１と同様にしてリチウムイオン二次電池（ボタン型二次電池）を製造した。
３．リチウムイオン二次電池の特性評価
製造したボタン型二次電池を評価電池として用いて、実施例１と同様にして充放電試験を行い、電池特性（放電容量、初期充放電効率及びサイクル特性）の評価を行った。評価結果を表１の該当欄に示す。 [Examples 8 and 9, Comparative Examples 8 to 11]
1. Production of Composite Particles Content (ratio) of graphite material (natural graphite + graphitic fiber), metal particles and carbonaceous material (carbonaceous material (A) + carbonaceous material (B)) in the composite particle [unit: The amount of natural graphite, graphite fibers, metal particles, the precursor of the carbonaceous material (A) and the precursor of the carbonaceous material (B) adjusted so that the mass%] is as shown in Table 1. Except for, composite particles were produced in the same manner as in Example 7.
2. Production of Lithium Ion Secondary Battery A lithium ion secondary battery (button type secondary battery) was produced in the same manner as in Example 1 using the produced composite particles.
3. Characteristic Evaluation of Lithium Ion Secondary Battery Using the manufactured button type secondary battery as an evaluation battery, a charge / discharge test was conducted in the same manner as in Example 1, and the battery characteristics (discharge capacity, initial charge / discharge efficiency and cycle characteristics) were Evaluation was performed. The evaluation results are shown in the corresponding column of Table 1.

［比較例１２］
１．複合粒子の製造
複合粒子中の黒鉛質材料、金属化合物粒子及び炭素質材料（炭素質材料（Ａ）＋炭素質材料（Ｂ））の含有率（割合）［単位：質量％］が表１に示すもの（本発明の範囲内）となるように、混合金属化合物粒子（実施例１で用いた、表面が酸化されたシリコン粒子）、炭素質材料の前駆体（実施例１で用いた、軟化点１１０℃、平均粒子径３μｍ、残炭率６０％のコールタールピッチ粉末）及び黒鉛質材料（実施例１で用いた、天然黒鉛を粉砕して、平均粒子径３μｍ、比表面積１４．５ｍ２／ｇに調整したもの）の配合量を調整して混合し、混合物に圧縮力、せん断力を繰り返し付与できる装置にてメカノケミカル処理を行い、メカノケミカル処理物を得た。次に、得られたメカノケミカル処理物を窒素気流中１０００℃で焼成処理し、複合粒子を製造した。
２．リチウムイオン二次電池の製造
製造した複合粒子を用いて、実施例１と同様にしてリチウムイオン二次電池（ボタン型二次電池）を製造した。
３．リチウムイオン二次電池の特性評価
製造したボタン型二次電池を評価電池として用いて、実施例１と同様にして充放電試験を行い、電池特性（放電容量、初期充放電効率及びサイクル特性）の評価を行った。評価結果を表１の該当欄に示す。 [Comparative Example 12]
1. Production of Composite Particles Table 1 shows the content (ratio) [unit: mass%] of the graphite material, metal compound particles, and carbonaceous material (carbonaceous material (A) + carbonaceous material (B)) in the composite particle. Mixed metal compound particles (silicon particles with oxidized surfaces used in Example 1), carbonaceous material precursors (softened as used in Example 1), as shown (within the scope of the present invention) A coal tar powder having a point of 110 ° C., an average particle diameter of 3 μm, and a residual carbon ratio of 60%) and a graphite material (natural graphite used in Example 1 was pulverized to have an average particle diameter of 3 μm and a specific surface area of 14.5 m 2. / G) was adjusted and mixed, and the mixture was subjected to mechanochemical treatment with an apparatus capable of repeatedly applying compressive force and shearing force to obtain a mechanochemically treated product. Next, the obtained mechanochemically treated product was fired at 1000 ° C. in a nitrogen stream to produce composite particles.
2. Production of Lithium Ion Secondary Battery A lithium ion secondary battery (button type secondary battery) was produced in the same manner as in Example 1 using the produced composite particles.
3. Characteristic Evaluation of Lithium Ion Secondary Battery Using the manufactured button type secondary battery as an evaluation battery, a charge / discharge test was conducted in the same manner as in Example 1, and the battery characteristics (discharge capacity, initial charge / discharge efficiency and cycle characteristics) were Evaluation was performed. The evaluation results are shown in the corresponding column of Table 1.

なお、表１において、以下の数値には下線を付している。
（１）複合粒子中の金属粒子及び金属化合物粒子の合計の含有率〔表１（２／３）の金属粒子及び金属化合物粒子の欄の「複合粒子中の含有率［質量％］」〕が１質量％以上３０質量％未満の範囲外であるもの
（２）複合粒子中の炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計の含有率〔表１（２／３）の炭素質材料の欄の「複合粒子中の含有率［質量％］」〕が２〜５０質量％の範囲外であるもの
（３）炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計に対する炭素質材料（Ａ）の割合〔表１（２／３）の炭素質材料の欄の「炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計に対する炭素質材料（Ａ）の割合［質量％］」〕が２０〜８０質量％の範囲外であるもの
（４）複合粒子の空隙率〔表１（３／３）の複合粒子の欄の「空隙率［体積％］」〕が１０〜７０体積％の範囲外であるもの
（５）複合粒子の表面から複合粒子の粒子径の１／８の厚さよりも内側に、複合粒子の空隙率の７０％以上が偏析しているものではないもの〔表１（３／３）の複合粒子の欄の「中心部分空隙／全空隙［体積％］」が７０体積％未満であるもの〕
（６）複合粒子の表面から複合粒子の粒子径の１／８の厚さよりも内側に、金属粒子及び金属化合物粒子の７０％以上が偏析しているものではないもの〔表１（３／３）の複合粒子の欄の「中心部分金属／全金属［質量％］」が７０質量％未満であるもの〕 In Table 1, the following numerical values are underlined.
(1) The total content of the metal particles and metal compound particles in the composite particles [“content in composite particles [% by mass]” in the column of metal particles and metal compound particles in Table 1 (2/3)] (2) Total content of carbonaceous material (A) and carbonaceous material (B) in the composite particles [carbonaceous material in Table 1 (2/3) (3) Carbonaceous material with respect to the total of carbonaceous material (A) and carbonaceous material (B) whose “content in composite particles [mass%]” in the column of material is outside the range of 2 to 50 mass% Ratio of material (A) [The ratio of carbonaceous material (A) to the total of carbonaceous material (A) and carbonaceous material (B) in the column of carbonaceous material in Table 1 (2/3) [mass%] ]] Out of the range of 20 to 80% by mass (4) Porosity of composite particles [Porosity [volume%] in the composite particle column of Table 1 (3/3) ] Out of the range of 10 to 70% by volume (5) 70% or more of the porosity of the composite particles segregates from the surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles. [In the composite particle column of Table 1 (3/3), “center part void / total void [volume%]” is less than 70 volume%]
(6) 70% or more of metal particles and metal compound particles are not segregated from the surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles [Table 1 (3/3 ) In which “center metal / total metal [mass%]” in the composite particle column is less than 70 mass%]

［特性評価の結果の解説］
本発明の範囲内の複合粒子を負極材料として作用電極を作製した場合、黒鉛の理論容量を超える放電容量を示しつつ（表１の「放電容量」の欄を参照）、優れた初期充放電効率（表１の「初期充放電効率」の欄を参照）とサイクル特性（表１の「サイクル特性」の欄を参照）を発現することがわかった。
一方、本発明の範囲外の複合粒子を負極材料として作用電極を作製した場合、放電容量、初期充放電効率及びサイクル特性のうち、少なくとも１つが不十分であった。 [Explanation of characterization results]
When a working electrode was prepared using a composite particle within the scope of the present invention as a negative electrode material, the discharge capacity exceeded the theoretical capacity of graphite (see the “Discharge capacity” column in Table 1), and excellent initial charge / discharge efficiency. It was found that it exhibited the cycle characteristics (see the “Cycle Characteristics” column in Table 1) (see the “Initial Charge / Discharge Efficiency” column in Table 1).
On the other hand, when a working electrode was produced using composite particles outside the scope of the present invention as a negative electrode material, at least one of discharge capacity, initial charge / discharge efficiency, and cycle characteristics was insufficient.

本発明の複合粒子を負極材料として用いるリチウムイオン二次電池は、それを搭載する機器の小型化及び高性能化に有効に寄与する。   The lithium ion secondary battery using the composite particles of the present invention as a negative electrode material effectively contributes to the downsizing and high performance of the device on which the lithium ion secondary battery is mounted.

１ 外装カップ
２ 作用電極（負極）
３ 外装缶
４ 対極（正極）
５ セパレータ
６ 絶縁ガスケット
７ａ、７ｂ集電体
８ リチウムと合金化可能な金属粒子及び／又は金属化合物粒子
９ 炭素質材料（Ａ）
１０ 炭素質材料（Ｂ）
１１ 空隙
１２ 黒鉛質材料
１３ 黒鉛質繊維 1 exterior cup 2 working electrode (negative electrode)
3 Exterior can 4 Counter electrode (positive electrode)
5 Separator 6 Insulating gasket 7a, 7b Current collector 8 Metal particles and / or metal compound particles that can be alloyed with lithium 9 Carbonaceous material (A)
10 Carbonaceous material (B)
11 Void 12 Graphite material 13 Graphite fiber

Claims (8)

リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）とからなり、前記金属粒子及び／又は金属化合物粒子を前記炭素質材料（Ａ）が結着し、かつ空隙を有する部材の表面を、炭素質材料（Ｂ）及び黒鉛質材料で被覆した複合粒子であって、
前記複合粒子中の前記金属粒子、前記金属化合物粒子、前記炭素質材料（Ａ）、前記炭素質材料（Ｂ）及び前記黒鉛質材料の含有率が、
金属粒子及び金属化合物粒子の合計：１質量％以上３０質量％未満、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：２〜５０質量％、かつ
黒鉛質材料：２０〜９７質量％であり、
前記炭素質材料（Ａ）及び前記炭素質材料（Ｂ）の合計に対する前記炭素質材料（Ａ）の割合が２０〜８０質量％であり、
前記複合粒子の空隙率が１０〜７０％であり、
前記複合粒子の外表面から前記複合粒子の粒子径の１／８の厚さよりも内側に、前記複合粒子の空隙率の７０％以上が偏析し、かつ前記金属粒子及び前記金属化合物粒子の７０％以上が偏析しているリチウムイオン二次電池負極用複合粒子。 It consists of metal particles and / or metal compound particles that can be alloyed with lithium, and a carbonaceous material (A), and the carbonaceous material (A) binds the metal particles and / or metal compound particles, and voids. A composite particle obtained by coating the surface of a member having a carbonaceous material (B) and a graphite material,
The content of the metal particles, the metal compound particles, the carbonaceous material (A), the carbonaceous material (B), and the graphite material in the composite particles is as follows:
Total of metal particles and metal compound particles: 1% by mass or more and less than 30% by mass,
The total of the carbonaceous material (A) and the carbonaceous material (B): 2 to 50% by mass, and the graphite material: 20 to 97% by mass,
The ratio of the carbonaceous material (A) to the total of the carbonaceous material (A) and the carbonaceous material (B) is 20 to 80% by mass,
The porosity of the composite particles is 10 to 70%,
70% or more of the porosity of the composite particles segregates from the outer surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles, and 70% of the metal particles and the metal compound particles The composite particle for lithium ion secondary battery negative electrodes in which the above is segregated. 前記黒鉛質材料の少なくとも一部が黒鉛質繊維である、請求項１に記載の複合粒子。   The composite particle according to claim 1, wherein at least a part of the graphite material is a graphite fiber. 請求項１又は２に記載のリチウムイオン二次電池負極用複合粒子を負極材料として用いるリチウムイオン二次電池用負極。   The negative electrode for lithium ion secondary batteries which uses the composite particle for lithium ion secondary battery negative electrodes of Claim 1 or 2 as negative electrode material. 請求項３に記載のリチウムイオン二次電池用負極を有するリチウムイオン二次電池。   The lithium ion secondary battery which has a negative electrode for lithium ion secondary batteries of Claim 3. リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）の前駆体とを混合し、造粒する造粒体製造工程と、
前記造粒体製造工程で得られる造粒体に、炭素質材料（Ｂ）の前駆体及び黒鉛質材料を付着させる付着工程と、
前記付着工程で得られる付着物を焼成する焼成工程と
を備える、
リチウムと合金化可能な金属粒子及び／又は金属化合物粒子と、炭素質材料（Ａ）とからなり、前記金属粒子及び／又は金属化合物粒子を前記炭素質材料が結着し、かつ空隙を有する部材の表面を、炭素質材料（Ｂ）及び黒鉛質材料で被覆したリチウムイオン二次電池負極用複合粒子の製造方法。 A granule manufacturing process in which metal particles and / or metal compound particles that can be alloyed with lithium and a precursor of the carbonaceous material (A) are mixed and granulated;
An adhesion step of attaching a precursor of carbonaceous material (B) and a graphite material to the granule obtained in the granule production step;
A firing step of firing the deposit obtained in the attaching step,
A member comprising metal particles and / or metal compound particles that can be alloyed with lithium, and a carbonaceous material (A), wherein the carbonaceous material binds the metal particles and / or metal compound particles and has voids. Of the composite particles for a negative electrode of a lithium ion secondary battery whose surface is coated with a carbonaceous material (B) and a graphite material. 前記複合粒子中の前記金属粒子、前記金属化合物粒子、前記炭素質材料（Ａ）、前記炭素質材料（Ｂ）及び前記黒鉛質材料の含有率が、
金属粒子及び金属化合物粒子の合計：１質量％以上３０質量％未満、
炭素質材料（Ａ）及び炭素質材料（Ｂ）の合計：２〜５０質量％、かつ
黒鉛質材料：２０〜９７質量％であり、
前記複合粒子の空隙率が１０〜７０％であり、
前記複合粒子の外表面から前記複合粒子の粒子径の１／８の厚さよりも内側に、前記複合粒子の空隙率の７０％以上が偏析し、かつ前記金属粒子及び前記金属化合物粒子の７０％以上が偏析している、請求項５に記載の製造方法。 The content of the metal particles, the metal compound particles, the carbonaceous material (A), the carbonaceous material (B), and the graphite material in the composite particles is as follows:
Total of metal particles and metal compound particles: 1% by mass or more and less than 30% by mass,
The total of the carbonaceous material (A) and the carbonaceous material (B): 2 to 50% by mass, and the graphite material: 20 to 97% by mass,
The porosity of the composite particles is 10 to 70%,
70% or more of the porosity of the composite particles segregates from the outer surface of the composite particles to the inside of the thickness of 1/8 of the particle diameter of the composite particles, and 70% of the metal particles and the metal compound particles The manufacturing method according to claim 5, wherein the above is segregated. 前記黒鉛質材料の少なくとも一部が黒鉛質繊維である、請求項５又は６に記載の製造方法。   The manufacturing method according to claim 5 or 6, wherein at least a part of the graphite material is a graphite fiber. 前記炭素質材料（Ａ）の前駆体の残炭率が前記炭素質材料（Ｂ）の前駆体の残炭率よりも小さい、請求項５〜７のいずれか１項に記載の製造方法。   The manufacturing method of any one of Claims 5-7 with which the carbon residue rate of the precursor of the said carbonaceous material (A) is smaller than the carbon residue rate of the precursor of the said carbonaceous material (B).
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