JP2008198427A - Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery - Google Patents

Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery Download PDF

Info

Publication number
JP2008198427A
JP2008198427A JP2007030824A JP2007030824A JP2008198427A JP 2008198427 A JP2008198427 A JP 2008198427A JP 2007030824 A JP2007030824 A JP 2007030824A JP 2007030824 A JP2007030824 A JP 2007030824A JP 2008198427 A JP2008198427 A JP 2008198427A
Authority
JP
Japan
Prior art keywords
lithium ion
ion battery
negative electrode
carbon fiber
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2007030824A
Other languages
Japanese (ja)
Inventor
Rika Sato
里佳 佐藤
Shinichi Toyosawa
真一 豊澤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bridgestone Corp
Original Assignee
Bridgestone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bridgestone Corp filed Critical Bridgestone Corp
Priority to JP2007030824A priority Critical patent/JP2008198427A/en
Publication of JP2008198427A publication Critical patent/JP2008198427A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a negative electrode for lithium ion battery having a sufficient charge and discharge capacity as well as superior rapid charge and discharge characteristics. <P>SOLUTION: The manufacturing method of a negative electrode for lithium ion battery comprises (i) a process to produce a fibril-like polymer by electrolytic oxidation polymerization of a compound having an aromatic ring on a conductive substrate 1, (ii) a process to produce carbon fiber 2 on the conductive substrate by calcining the fibril-like polymer, (iii) a process to cover the carbon fiber 2 with a conductive metal 3, and (iv) a process to carry metal particulates 4 capable of storing and releasing lithium ion on the conductive metal 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、リチウムイオン電池用負極の製造方法及び該方法で製造された負極を具えるリチウムイオン電池に関し、特に高速充放電特性に優れ、十分な充放電容量を有するリチウムイオン電池に関するものである。   The present invention relates to a method for producing a negative electrode for a lithium ion battery and a lithium ion battery including the negative electrode produced by the method, and particularly relates to a lithium ion battery having excellent high-speed charge / discharge characteristics and sufficient charge / discharge capacity. .

昨今、携帯用端末やモバイル通信機器として、リチウムイオン電池が広く普及している。該リチウムイオン電池は、現存する二次電池の中でも最もエネルギー密度が高いため、該リチウムイオン電池をハイブリッド自動車や燃料電池自動車の補助電源として、あるいは定置用大型電源として使用することも検討されている。   Recently, lithium ion batteries are widely used as portable terminals and mobile communication devices. Since the lithium ion battery has the highest energy density among the existing secondary batteries, it is considered to use the lithium ion battery as an auxiliary power source for a hybrid vehicle or a fuel cell vehicle or as a large power source for stationary use. .

上記リチウムイオン電池は、リチウムイオンを電気化学的に吸蔵・離脱可能な層状構造の正極（例えば、ＬｉＣｏＯ2）と同特性を有する負極（例えば、黒鉛）がリチウムイオンを溶解した電解液を介して対向した構造を有する電池であり、一般に、正極と負極との短絡を防止するために電解液を透過しうる多孔質ポリマー膜が両極材の間に配置された構造を有している。 The lithium ion battery includes a negative electrode (for example, graphite) having the same characteristics as a positive electrode (for example, LiCoO 2 ) having a layered structure capable of electrochemically inserting and extracting lithium ions via an electrolytic solution in which lithium ions are dissolved. A battery having a structure opposite to each other, and generally has a structure in which a porous polymer film capable of permeating an electrolytic solution is disposed between both electrodes in order to prevent a short circuit between a positive electrode and a negative electrode.

そして、現在、高速充放電用途のリチウムイオン電池の負極としては、メソフェーズカーボンマイクロビーズ（ＭＣＭＢ）等のソフトカーボンにＶＧＣＦ等のファイバー状カーボンを添加して調製したペーストを銅箔に塗布して形成した電極や、ハードカーボンからなるペーストを銅箔に塗布して形成した電極が使用されている。しかしながら、いずれの電極も、低速充電高速放電での性能は一定のレベルに達しているものの、高速充放電特性については依然として改良の余地が大きい。   Currently, the negative electrode of lithium ion batteries for high-speed charge / discharge applications is formed by applying a paste prepared by adding fiber carbon such as VGCF to soft carbon such as mesophase carbon microbeads (MCMB) to copper foil. And electrodes formed by applying a paste made of hard carbon on a copper foil are used. However, although all of the electrodes have reached a certain level of performance in low-speed charge and high-speed discharge, there is still much room for improvement in the high-speed charge / discharge characteristics.

また、高容量な負極活物質として金属スズ等が知られているが、金属スズ等を負極に使用したリチウムイオン電池は、初期不可逆容量が大きく、充放電に伴う不可逆な体積膨張によって、微粉化や集電性の低下等の問題があるため、実用化が困難である。   Also, metal tin is known as a high capacity negative electrode active material, but lithium ion batteries using metal tin as the negative electrode have a large initial irreversible capacity and are pulverized due to irreversible volume expansion associated with charge and discharge. It is difficult to put it into practical use because of problems such as low current collection and current collection.

マテリアルインテグレーション, Vol.17, No.1 (2004), p.45Material Integration, Vol.17, No.1 (2004), p.45 Electrochimica Acfa, Vol.45, p31-50 (1994)Electrochimica Acfa, Vol.45, p31-50 (1994)

また、本発明者らは、（１）特定の方法で作製した３次元連続状炭素繊維自体を活物質とした電極（特願２００５−３３１６２１号及び特願２００６−２６２６９７号）や、（２）該３次元連続状炭素繊維に金属微粒子を担持した電極（特願２００５−１９７２３８号及び特願２００６−１５５９５１号）等を開発してきたが、（１）の電極は、高速充放電特性に優れるものの、容量自体が不十分であり、一方、（２）の電極は、容量及び高速充放電特性の双方が向上しているものの、未だ要求レベルを満足できていない。   In addition, the present inventors have (1) electrodes (Japanese Patent Application Nos. 2005-331621 and 2006-262697) using a three-dimensional continuous carbon fiber itself produced by a specific method as an active material, and (2) Electrodes (Japanese Patent Application Nos. 2005-1972238 and 2006-155951) in which metal fine particles are supported on the three-dimensional continuous carbon fiber have been developed. The electrode of (1) has excellent high-speed charge / discharge characteristics. The capacity itself is insufficient. On the other hand, although both the capacity and the high-speed charge / discharge characteristics are improved, the electrode (2) still does not satisfy the required level.

そこで、本発明の目的は、上記の問題を解決し、十分な充放電容量を有する上、高速充放電特性に優れたリチウムイオン電池用負極の製造方法、並びに該方法で製造された負極を具えたリチウムイオン電池を提供することにある。   Accordingly, an object of the present invention is to provide a method for producing a negative electrode for a lithium ion battery that solves the above problems, has a sufficient charge / discharge capacity, and is excellent in high-speed charge / discharge characteristics, and a negative electrode produced by the method. Another object is to provide a lithium ion battery.

本発明者らは、上記目的を達成するために鋭意検討した結果、導電性基板上において芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを生成させ、該フィブリル状ポリマーを焼成して炭素繊維を形成し、更に、該炭素繊維を導電性金属で被覆した後、該導電性金属上にリチウムを吸蔵・脱離可能な金属微粒子を担持して作製した電極をリチウムイオン電池の負極として使用することで、十分な充放電容量を有しつつ、優れた高速充放電特性に優れたリチウムイオン電池が得られることを見出し、本発明を完成させるに至った。   As a result of diligent investigations to achieve the above object, the inventors of the present invention produced a fibril polymer by electrolytic oxidation polymerization of a compound having an aromatic ring on a conductive substrate, and the fibril polymer was calcined to produce carbon. After forming the fiber and coating the carbon fiber with a conductive metal, the electrode made by supporting metal fine particles capable of inserting and extracting lithium on the conductive metal is used as the negative electrode of the lithium ion battery. As a result, it was found that a lithium ion battery having an excellent high-speed charge / discharge characteristic while having a sufficient charge / discharge capacity was obtained, and the present invention was completed.

即ち、本発明のリチウムイオン電池用負極の製造方法は、導電性基板と、該導電性基板上に形成された炭素繊維と、該炭素繊維を被覆する導電性金属と、該導電性金属上に担持されたリチウムを吸蔵・脱離可能な金属微粒子とからなるリチウムイオン電池用負極の製造方法であって、
(i)導電性基板上において、芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを生成させる工程と、
(ii)該フィブリル状ポリマーを焼成して導電性基板上に炭素繊維を生成させる工程と、
(iii)該炭素繊維を導電性金属で被覆する工程と、
(iv)該導電性金属上にリチウムを吸蔵・脱離可能な金属微粒子を担持する工程と
を含むことを特徴とする。 That is, the method for producing a negative electrode for a lithium ion battery according to the present invention comprises a conductive substrate, a carbon fiber formed on the conductive substrate, a conductive metal covering the carbon fiber, and the conductive metal. A method for producing a negative electrode for a lithium ion battery comprising fine metal particles capable of inserting and extracting supported lithium,
(i) a step of electrolytically oxidatively polymerizing a compound having an aromatic ring on a conductive substrate to produce a fibrillated polymer;
(ii) firing the fibrillated polymer to form carbon fibers on a conductive substrate;
(iii) coating the carbon fiber with a conductive metal;
and (iv) carrying a metal fine particle capable of inserting and extracting lithium on the conductive metal.

本発明のリチウムイオン電池用負極の製造方法の好適例においては、前記炭素繊維を被覆する導電性金属がＣｕである。   In the suitable example of the manufacturing method of the negative electrode for lithium ion batteries of this invention, the electroconductive metal which coat | covers the said carbon fiber is Cu.

本発明のリチウムイオン電池用負極の製造方法の他の好適例においては、前記リチウムを吸蔵・脱離可能な金属微粒子がＳｎ微粒子である。   In another preferred embodiment of the method for producing a negative electrode for a lithium ion battery of the present invention, the metal fine particles capable of inserting and extracting lithium are Sn fine particles.

また、本発明のリチウムイオン電池は、上記の方法で製造したリチウムイオン電池用負極を具えることを特徴とする。   Moreover, the lithium ion battery of the present invention is characterized by comprising a negative electrode for a lithium ion battery produced by the above method.

本発明によれば、導電性基板上において芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを生成させ、該フィブリル状ポリマーを焼成して炭素繊維を形成し、更に、該炭素繊維を導電性金属で被覆した後、該導電性金属上にリチウムを吸蔵・脱離可能な金属微粒子を担持することで、高速充放電特性に優れたリチウムイオン電池用負極を製造することができる。また、かかる方法で製造された負極を具え、十分な充放電容量を有し、高速充放電特性に優れたリチウムイオン電池を提供することができる。   According to the present invention, a compound having an aromatic ring is electrolytically oxidatively polymerized on a conductive substrate to form a fibril-like polymer, the fibril-like polymer is baked to form carbon fibers, and the carbon fibers are further electrically conductive. After coating with a conductive metal, a negative electrode for a lithium ion battery excellent in high-speed charge / discharge characteristics can be produced by supporting metal fine particles capable of inserting and extracting lithium on the conductive metal. In addition, it is possible to provide a lithium ion battery having a negative electrode manufactured by such a method, having a sufficient charge / discharge capacity, and excellent in high-speed charge / discharge characteristics.

＜リチウムイオン電池用負極の製造方法＞
以下に、図１を参照しながら、本発明のリチウムイオン電池用負極の製造方法を詳細に説明する。本発明のリチウムイオン電池用負極の製造方法は、(i)導電性基板１上において、芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを生成させる工程と、(ii)該フィブリル状ポリマーを焼成して導電性基板１上に炭素繊維２を形成する工程と、(iii)該炭素繊維２を導電性金属３で被覆する工程と、(iv)該導電性金属３上にリチウムを吸蔵・脱離可能な金属微粒子４を担持する工程を含むことを特徴とし、該方法によれば、導電性基板１と、該導電性基板１上に形成された炭素繊維２と、該炭素繊維２を被覆する導電性金属３と、該導電性金属３上に担持されたリチウムを吸蔵・脱離可能な金属微粒子４とからなるリチウムイオン電池用負極を製造することができる。 <Method for producing negative electrode for lithium ion battery>
Below, the manufacturing method of the negative electrode for lithium ion batteries of this invention is demonstrated in detail, referring FIG. The method for producing a negative electrode for a lithium ion battery according to the present invention comprises: (i) a step of electrolytically polymerizing a compound having an aromatic ring on the conductive substrate 1 to form a fibril polymer; and (ii) the fibril polymer. Firing carbon to form carbon fibers 2 on the conductive substrate 1, (iii) coating the carbon fibers 2 with the conductive metal 3, and (iv) occlusion of lithium on the conductive metal 3. The method includes the step of supporting the detachable metal fine particles 4, and according to the method, the conductive substrate 1, the carbon fibers 2 formed on the conductive substrate 1, and the carbon fibers 2 A negative electrode for a lithium ion battery comprising a conductive metal 3 covering the metal and metal fine particles 4 capable of inserting and extracting lithium supported on the conductive metal 3 can be produced.

上記リチウムイオン電池用負極を構成する炭素繊維は、３次元網目構造を有し、該網目構造が金属微粒子の電気化学反応に伴う体積変化を効率よく吸収するため、電気的に絶縁となる部分が生じ難く、充放電容量が低下し難く、また、高速充放電特性の向上にも好適である。また、該炭素繊維が導電性金属で被覆されることにより、負極における導電性が更に確保される上、金属微粒子との密着力が向上し、更に優れた高速充放電特性を達成することが可能となる。そのため、該リチウムイオン電池用負極を用いたリチウムイオン電池は、十分な充放電容量を有する上、高速充放電特性に特に優れる。   The carbon fiber constituting the negative electrode for a lithium ion battery has a three-dimensional network structure, and the network structure efficiently absorbs the volume change accompanying the electrochemical reaction of the metal fine particles. It is difficult to occur, the charge / discharge capacity is difficult to decrease, and is suitable for improving high-speed charge / discharge characteristics. In addition, by covering the carbon fiber with a conductive metal, it is possible to further ensure the conductivity in the negative electrode, improve the adhesion with the metal fine particles, and achieve further excellent high-speed charge / discharge characteristics. It becomes. Therefore, a lithium ion battery using the negative electrode for a lithium ion battery has a sufficient charge / discharge capacity and is particularly excellent in high-speed charge / discharge characteristics.

本発明のリチウムイオン電池用負極の製造方法では、(i)工程で、導電性基板１上において、芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを形成する。使用する導電性基板１としては、導電性を有する限り特に限定されず、ステンレス、チタン、ニッケル等のプレートが挙げられる。また、上記芳香環を有する化合物としては、ベンゼン環を有する化合物、芳香族複素環を有する化合物を挙げることができる。ここで、ベンゼン環を有する化合物としては、アニリン及びアニリン誘導体が好ましく、芳香族複素環を有する化合物としては、ピロール、チオフェン及びこれらの誘導体が好ましい。これら芳香環を有する化合物は、一種単独で用いてもよいし、二種以上の混合物として用いてもよい。   In the method for producing a negative electrode for a lithium ion battery of the present invention, in step (i), a compound having an aromatic ring is electrolytically oxidized and polymerized on the conductive substrate 1 to form a fibril polymer. The conductive substrate 1 to be used is not particularly limited as long as it has conductivity, and examples thereof include plates made of stainless steel, titanium, nickel, and the like. Examples of the compound having an aromatic ring include a compound having a benzene ring and a compound having an aromatic heterocycle. Here, as the compound having a benzene ring, aniline and aniline derivatives are preferable, and as the compound having an aromatic heterocyclic ring, pyrrole, thiophene and derivatives thereof are preferable. These compounds having an aromatic ring may be used singly or as a mixture of two or more.

上記電解酸化重合においては、原料の芳香環を有する化合物と共に、酸を混在させることが好ましい。この場合、酸の負イオンがドーパントとして合成されるフィブリル状ポリマー中に取り込まれ、導電性に優れたフィブリル状ポリマーが得られ、このフィブリル状ポリマーを用いることにより最終的に炭素繊維の導電性を更に向上させることができる。ここで、電解酸化重合の際に混在させる酸としては、Ｈ2ＳＯ4、ＨＢＦ4、ＨＣｌ、ＨＣｌＯ4等を例示することができる。また、該酸の濃度は、0.1〜3mol/Lの範囲が好ましく、0.5〜2.5mol/Lの範囲が更に好ましい。 In the electrolytic oxidation polymerization, it is preferable to mix an acid together with a raw material compound having an aromatic ring. In this case, the negative ion of the acid is taken into the fibril polymer synthesized as a dopant to obtain a fibril polymer excellent in conductivity. By using this fibril polymer, the conductivity of the carbon fiber is finally improved. Further improvement can be achieved. Here, examples of the acid mixed in the electrolytic oxidation polymerization include H 2 SO 4 , HBF 4 , HCl, and HClO 4 . The acid concentration is preferably in the range of 0.1 to 3 mol / L, more preferably in the range of 0.5 to 2.5 mol / L.

上記(i)工程は、芳香環を有する化合物を含む溶液中に、上記導電性基板を作用極として浸漬し、更に対極を浸漬し、両極間に芳香環を有する化合物の酸化電位以上の電圧を印加するか、または該芳香環を有する化合物が重合するのに充分な電圧が確保できるような条件の電流を通電すればよく、これにより導電性基板（作用極）上にフィブリル状ポリマーが生成する。ここで、対極としては、ステンレススチール、白金、カーボン等の導電性物質からなる板や多孔質支持体等を用いることができる。この電解酸化重合法によるフィブリル状ポリマーの合成方法の一例を挙げると、Ｈ2ＳＯ4等の酸及びアニリン等の芳香環を有する化合物を含む電解溶液中に導電性基板からなる作用極及び対極を浸漬し、両極間に0.1〜1000mA/cm2、好ましくは0.2〜100mA/cm2の電流を通電して、導電性基板からなる作用極側にフィブリル状ポリマーを重合析出させる方法等が例示される。なお、フィブリル状ポリマーは、導電性基板からなる作用極の対極と対向する面に主として生成する。ここで、芳香環を有する化合物の電解溶液中の濃度は、0.05〜3mol/Lが好ましく、0.25〜1.5mol/Lがより好ましい。また、電解溶液には、上記成分に加え、ｐＨを調製するために可溶性塩等を適宜添加してもよい。 In the step (i), the conductive substrate is immersed in a solution containing a compound having an aromatic ring as a working electrode, the counter electrode is further immersed, and a voltage equal to or higher than the oxidation potential of the compound having an aromatic ring between both electrodes is applied. The fibrillar polymer is generated on the conductive substrate (working electrode) by applying or applying a current under such a condition that a voltage sufficient to polymerize the compound having an aromatic ring can be secured. . Here, as the counter electrode, a plate made of a conductive material such as stainless steel, platinum, or carbon, a porous support, or the like can be used. An example of a method for synthesizing a fibrillated polymer by this electrolytic oxidation polymerization method is as follows. An working electrode and a counter electrode made of a conductive substrate are included in an electrolytic solution containing an acid such as H 2 SO 4 and a compound having an aromatic ring such as aniline. Examples include a method in which a fibrillated polymer is polymerized and deposited on the side of the working electrode made of a conductive substrate by immersing and applying a current of 0.1 to 1000 mA / cm 2 , preferably 0.2 to 100 mA / cm 2 between both electrodes. . The fibril polymer is mainly generated on the surface facing the counter electrode of the working electrode made of a conductive substrate. Here, the concentration of the compound having an aromatic ring in the electrolytic solution is preferably 0.05 to 3 mol / L, and more preferably 0.25 to 1.5 mol / L. Moreover, in addition to the said component, you may add a soluble salt etc. to an electrolyte solution suitably in order to adjust pH.

上記芳香環を有する化合物を電解酸化重合して得られるフィブリル状ポリマーは、通常、３次元連続構造を有し、直径が30〜数百nmで、好ましくは40〜500nmであり、長さが0.5μm〜100mmで、好ましくは1μm〜10mmである。   The fibril-like polymer obtained by electrolytic oxidation polymerization of the compound having an aromatic ring usually has a three-dimensional continuous structure, has a diameter of 30 to several hundred nm, preferably 40 to 500 nm, and has a length of 0.5. It is μm to 100 mm, preferably 1 μm to 10 mm.

本発明のリチウムイオン電池用負極の製造方法では、(ii)工程で、上記フィブリル状ポリマーを焼成し炭化することで、導電性基板１上に炭素繊維２を形成する。なお、(ii)工程の前に、フィブリル状ポリマーを水や有機溶剤等の溶媒で洗浄し、乾燥させることが好ましい。ここで、乾燥方法としては、特に制限されるものではないが、風乾、真空乾燥の他、流動床乾燥装置、気流乾燥機、スプレードライヤー等を使用した方法を例示することができる。   In the method for producing a negative electrode for a lithium ion battery of the present invention, the carbon fiber 2 is formed on the conductive substrate 1 by firing and carbonizing the fibrillated polymer in the step (ii). In addition, before the step (ii), it is preferable that the fibrillated polymer is washed with a solvent such as water or an organic solvent and dried. Here, the drying method is not particularly limited, and examples thereof include a method using a fluidized bed drying device, an air dryer, a spray dryer, etc., in addition to air drying and vacuum drying.

上記(ii)工程の焼成条件としては、特に限定されるものではなく、最適導電率となるように適宜設定すればよいが、特に高導電率を必要とする場合は、温度500〜3000℃、好ましくは600〜2800℃で、0.5〜6時間焼成することが好ましい。なお、本発明の製造方法では、焼成工程を非酸化性雰囲気中で行うことが好ましく、該非酸化性雰囲気としては、窒素雰囲気、アルゴン雰囲気、ヘリウム雰囲気等を挙げることができ、場合によっては水素雰囲気とすることもできる。   The firing conditions in the above step (ii) are not particularly limited, and may be set as appropriate so as to obtain optimum conductivity. Particularly, when high conductivity is required, the temperature is 500 to 3000 ° C., Preferably, baking is performed at 600 to 2800 ° C. for 0.5 to 6 hours. In the production method of the present invention, the firing step is preferably performed in a non-oxidizing atmosphere, and examples of the non-oxidizing atmosphere include a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere. It can also be.

上記炭素繊維は、通常、３次元連続構造を有し、直径が30〜数百nm、好ましくは40〜500nmであり、長さが0.5μm〜100mm、好ましくは1μm〜10mmであり、表面抵抗が106〜10-2Ω、好ましくは104〜10-2Ωである。また、該炭素繊維は、残炭率が90〜20％、好ましくは80〜25％である。該炭素繊維は、カーボン全体が３次元に連続した構造を有するため、粒状カーボンよりも導電性が高い。 The carbon fiber usually has a three-dimensional continuous structure, has a diameter of 30 to several hundred nm, preferably 40 to 500 nm, has a length of 0.5 μm to 100 mm, preferably 1 μm to 10 mm, and has a surface resistance. 10 6 to 10 −2 Ω, preferably 10 4 to 10 −2 Ω. The carbon fiber has a residual carbon ratio of 90 to 20%, preferably 80 to 25%. Since the carbon fiber has a structure in which the entire carbon is three-dimensionally continuous, the carbon fiber has higher conductivity than the granular carbon.

本発明のリチウムイオン電池用負極の製造方法では、(iii)工程で、上記導電性基板１上に形成された炭素繊維２を導電性金属３で被覆する。ここで、導電性金属としては、Ｃｕ、Ｎｉ、Ｚｎ等が挙げられ、これらの中でも、導電性の観点から、Ｃｕが特に好ましい。   In the method for producing a negative electrode for a lithium ion battery of the present invention, the carbon fiber 2 formed on the conductive substrate 1 is covered with the conductive metal 3 in the step (iii). Here, examples of the conductive metal include Cu, Ni, Zn, and the like. Among these, Cu is particularly preferable from the viewpoint of conductivity.

上記導電性金属による炭素繊維の被覆法としては、特に限定されるものではなく、例えば、無電解メッキ法、電解メッキ法等が挙げられる。また、導電性金属３の被覆量は、特に限定されるものではないが、0.4〜1mg/cm2の範囲が好ましい。導電性金属３の被覆量が0.4mg/cm2未満では、導電性被覆が1nm以下と薄く不安定であり、一方、1mg/cm2を超えると、導電性は確保できるが、その分、リチウムを吸蔵・脱離可能な金属の付着占有体積が減少してしまう。 The method for coating the carbon fiber with the conductive metal is not particularly limited, and examples thereof include an electroless plating method and an electrolytic plating method. Moreover, the coating amount of the conductive metal 3 is not particularly limited, but a range of 0.4 to 1 mg / cm 2 is preferable. When the coating amount of the conductive metal 3 is less than 0.4 mg / cm 2 , the conductive coating is thin and unstable at 1 nm or less. On the other hand, when the coating amount exceeds 1 mg / cm 2 , the conductivity can be ensured. This reduces the volume of metal deposited and occluded / desorbed.

本発明のリチウムイオン電池用負極の製造方法では、(iv)工程で、上記導電性金属３上にリチウムを吸蔵・脱離可能な金属微粒子４を担持する。ここで、リチウムを吸蔵・脱離可能な金属としては、Ｓｎ、Ｓｉ、Ｐｂ、Ａｌ、Ａｕ、Ｐｔ、Ｉｎ、Ｚｎ、Ｃｄ、Ａｇ及びＭｇ等が挙げられ、これらの中でも、充放電容量の観点から、Ｓｎが特に好ましい。   In the method for producing a negative electrode for a lithium ion battery of the present invention, metal fine particles 4 capable of inserting and extracting lithium are supported on the conductive metal 3 in the step (iv). Here, examples of the metal capable of inserting and extracting lithium include Sn, Si, Pb, Al, Au, Pt, In, Zn, Cd, Ag, and Mg. Among these, in terms of charge / discharge capacity Therefore, Sn is particularly preferable.

上記金属微粒子４の導電性金属３上への担持法としては、電解メッキ法、無電解メッキ法、スパッタリング法等が挙げられるが、金属微粒子の担持率の調整が容易な点で、電解メッキ法が好ましい。該電解メッキ法では、メッキしたい金属のイオンを含む溶液を調製し、該溶液に上記炭素繊維を浸漬し、所定の電圧を印加することで、溶液から金属微粒子を導電性金属上に電気化学的に析出させることができ、しかも通電電荷量で金属微粒子の析出量を制御することができる。なお、金属微粒子４の担持量は、1.7〜5mg/cm2の範囲が好ましい。金属微粒子４の担持量が1.7mg/cm2未満では、充放電容量が不足し、一方、5mg/cm2を超えると、被膜厚の増大により、空隙が閉塞され、反応不活性な金属が発生し、利用効率が低下する。 Examples of the method for supporting the metal fine particles 4 on the conductive metal 3 include an electrolytic plating method, an electroless plating method, a sputtering method, and the like. Is preferred. In the electrolytic plating method, a solution containing ions of a metal to be plated is prepared, the carbon fiber is immersed in the solution, and a predetermined voltage is applied so that metal fine particles are electrochemically deposited on the conductive metal from the solution. In addition, the amount of metal fine particles can be controlled by the amount of electric charge. The supported amount of the metal fine particles 4 is preferably in the range of 1.7 to 5 mg / cm 2 . When the loading amount of the metal fine particles 4 is less than 1.7 mg / cm 2 , the charge / discharge capacity is insufficient. On the other hand, when it exceeds 5 mg / cm 2 , the voids are closed due to the increase in film thickness, and a reaction-inactive metal is generated. However, the utilization efficiency decreases.

上記リチウムイオン電池用負極の形状としては、特に制限はなく、電極として公知の形状の中から適宜選択することができる。例えば、シート状、円柱形状、板状形状、スパイラル形状等が挙げられる。   There is no restriction | limiting in particular as a shape of the said negative electrode for lithium ion batteries, It can select suitably from well-known shapes as an electrode. For example, a sheet shape, a columnar shape, a plate shape, a spiral shape, and the like can be given.

＜リチウムイオン電池＞
次に、本発明のリチウムイオン電池を詳細に説明する。本発明のリチウムイオン電池は、上述した方法で製造されたリチウムイオン電池用負極を備え、更に、正極、電解質、セパレーター等のリチウムイオン電池の技術分野で通常使用されている他の部材を備える。本発明のリチウムイオン電池は、上述した方法で製造されたリチウムイオン電池用負極を備えるため、十分な充放電容量を有し、高速充放電特性に特に優れる。 <Lithium ion battery>
Next, the lithium ion battery of the present invention will be described in detail. The lithium ion battery of the present invention includes a negative electrode for a lithium ion battery manufactured by the above-described method, and further includes other members that are usually used in the technical field of lithium ion batteries, such as a positive electrode, an electrolyte, and a separator. Since the lithium ion battery of the present invention includes the negative electrode for a lithium ion battery produced by the above-described method, it has a sufficient charge / discharge capacity and is particularly excellent in high-speed charge / discharge characteristics.

本発明のリチウムイオン電池の正極の活物質としては、ＬｉＣｏＯ2、ＬｉＮｉＯ2、ＬｉＭｎ2Ｏ4、ＬｉＦｅＯ2及びＬｉＦｅＰＯ4等のリチウム含有複合酸化物、リチウム金属、Ｖ2Ｏ5、Ｖ6Ｏ13、ＭｎＯ2、ＭｎＯ3等の金属酸化物、ＴｉＳ2、ＭｏＳ2等の金属硫化物、ポリアニリン等の導電性ポリマー等が好適に挙げられる。これら正極活物質は、１種単独で使用してもよく、２種以上を併用してもよい。上記正極には、必要に応じて導電助剤、結着剤を混合することができ、導電助剤としてはアセチレンブラック等が挙げられ、結着剤としてはポリフッ化ビニリデン（ＰＶＤＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、スチレン・ブタジエンゴム（ＳＢＲ）、カルボキシメチルセルロース（ＣＭＣ）等が挙げられる。これらの添加剤は、従来と同様の配合割合で用いることができる。 Examples of the active material for the positive electrode of the lithium ion battery of the present invention include lithium-containing composite oxides such as LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiFeO 2, and LiFePO 4 , lithium metal, V 2 O 5 , and V 6 O 13. Preferable examples include metal oxides such as MnO 2 and MnO 3 , metal sulfides such as TiS 2 and MoS 2 , and conductive polymers such as polyaniline. These positive electrode active materials may be used individually by 1 type, and may use 2 or more types together. If necessary, the positive electrode can be mixed with a conductive additive and a binder. Examples of the conductive assistant include acetylene black, and the binder includes polyvinylidene fluoride (PVDF), polytetrafluoro. Examples include ethylene (PTFE), styrene / butadiene rubber (SBR), carboxymethyl cellulose (CMC), and the like. These additives can be used at a blending ratio similar to the conventional one.

本発明のリチウムイオン電池の電解質としては、非水電解液やポリマー電解質を使用することができる。該非水電解液は、通常、非プロトン性有機溶媒に支持塩を溶解させてなり、所望に応じて各種添加剤を含有してもよい。ここで、該非プロトン性溶媒としては、１,２-ジメトキシエタン、テトラヒドロフラン、ジメチルカーボネート、ジエチルカーボネート、ジフェニルカーボネート、エチレンカーボネート、プロピレンカーボネート、γ-ブチロラクトン、γ-バレロラクトン、エチルメチルカーボネート等が挙げられる。また、支持塩としては、ＬｉＰＦ6、ＬｉＣｌＯ4、ＬｉＢＦ4、ＬｉＢＣ4Ｏ8、ＬｉＣＦ3ＳＯ3、ＬｉＡｓＦ6、ＬｉＣ4Ｆ9ＳＯ3、Ｌｉ(ＣＦ3ＳＯ2)2Ｎ及びＬｉ(Ｃ2Ｆ5ＳＯ2)2Ｎ等のリチウム塩が挙げられる。なお非水電解液中の支持塩の濃度としては、特に限定されるものではないが、0.2〜1.5mol/L（Ｍ）の範囲が好ましい。 As the electrolyte of the lithium ion battery of the present invention, a nonaqueous electrolytic solution or a polymer electrolyte can be used. The nonaqueous electrolytic solution is usually prepared by dissolving a supporting salt in an aprotic organic solvent, and may contain various additives as desired. Here, examples of the aprotic solvent include 1,2-dimethoxyethane, tetrahydrofuran, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate, γ-butyrolactone, γ-valerolactone, and ethyl methyl carbonate. . The supporting salts include LiPF 6 , LiClO 4 , LiBF 4 , LiBC 4 O 8 , LiCF 3 SO 3 , LiAsF 6 , LiC 4 F 9 SO 3 , Li (CF 3 SO 2 ) 2 N and Li (C 2 Examples thereof include lithium salts such as F 5 SO 2 ) 2 N. The concentration of the supporting salt in the nonaqueous electrolytic solution is not particularly limited, but is preferably in the range of 0.2 to 1.5 mol / L (M).

また、上記ポリマー電解質は、ポリマーと上記支持塩とを含むことが好ましく、更に上記非プロトン性有機溶媒を含むことが更に好ましく、目的に応じて種々の添加剤を更に含有してもよい。上記ポリマー電解質に用いるポリマーとしては、ポリマー電池用のゲル電解質に通常用いられるポリマーの総てを用いることができ、具体的には、ポリエチレンオキシド、ポリプロピレンオキシド、ポリアクリレート、ポリアクリロニトリル、エチレンオキシドユニットを含むポリアクリレート等が挙げられる。   The polymer electrolyte preferably contains a polymer and the supporting salt, more preferably contains the aprotic organic solvent, and may further contain various additives depending on the purpose. As the polymer used for the polymer electrolyte, all polymers usually used for gel electrolytes for polymer batteries can be used, and specifically include polyethylene oxide, polypropylene oxide, polyacrylate, polyacrylonitrile, ethylene oxide units. Polyacrylate etc. are mentioned.

本発明のリチウムイオン電池に使用できる他の部材としては、正負極間に、両極の接触による電流の短絡を防止する役割で介在させるセパレーターが挙げられる。セパレーターの材質としては、両極の接触を確実に防止し得、且つ電解液を通したり含んだりできる材料、例えば、ポリテトラフルオロエチレン、ポリプロピレン、ポリエチレン、セルロース系、ポリブチレンテレフタレート、ポリエチレンテレフタレート等の合成樹脂製の不織布、薄層フィルム等が好適に挙げられる。これらは、単体でも、混合物でも、共重合体でもよい。これらの中でも、厚さ20〜50μm程度のポリプロピレン又はポリエチレン製の微孔性フィルム、セルロース系、ポリブチレンテレフタレート、ポリエチレンテレフタレート等のフィルムが特に好適である。本発明では、上述のセパレーターの他にも、通常電池に使用されている公知の各部材が好適に使用できる。   Other members that can be used in the lithium ion battery of the present invention include a separator interposed between positive and negative electrodes in a role of preventing current short-circuiting due to contact between both electrodes. As the material of the separator, it is possible to reliably prevent contact between the two electrodes and to allow the electrolyte to pass through or to contain, for example, synthesis of polytetrafluoroethylene, polypropylene, polyethylene, cellulose, polybutylene terephthalate, polyethylene terephthalate, etc. Preferred examples include resin non-woven fabrics and thin layer films. These may be a single substance, a mixture or a copolymer. Among these, a polypropylene or polyethylene microporous film having a thickness of about 20 to 50 μm, a film made of cellulose, polybutylene terephthalate, polyethylene terephthalate, or the like is particularly suitable. In the present invention, in addition to the separators described above, known members that are normally used in batteries can be suitably used.

以上に説明した本発明のリチウムイオン電池の形態としては、特に制限はなく、コインタイプ、ボタンタイプ、ペーパータイプ、角型又はスパイラル構造の円筒型電池等、種々の公知の形態が好適に挙げられる。ボタンタイプの場合は、シート状の正極及び負極を作製し、該正極及び負極でセパレーターを挟む等して、リチウムイオン電池を作製することができる。また、スパイラル構造の場合は、例えば、シート状の正極を作製して集電体を挟み、これにシート状の負極を重ね合わせて巻き上げる等して、リチウムイオン電池を作製することができる。   The form of the lithium ion battery of the present invention described above is not particularly limited, and various known forms such as a coin type, a button type, a paper type, a square type or a spiral type cylindrical battery are preferably exemplified. . In the case of the button type, a lithium ion battery can be manufactured by preparing a sheet-like positive electrode and negative electrode and sandwiching a separator between the positive electrode and the negative electrode. In the case of a spiral structure, for example, a lithium ion battery can be manufactured by preparing a sheet-like positive electrode, sandwiching a current collector, and stacking and winding up the sheet-like negative electrode on the current collector.

以下に、実施例を挙げて本発明を更に詳しく説明するが、本発明は下記の実施例に何ら限定されるものではない。   Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

（実施例１）
＜金属担持炭素繊維−基板複合体の製造＞
アニリンモノマー 0.5mol/LとＨ2ＳＯ4 1.0mol/Lとを含む酸性水溶液中に、作用極としてＳＵＳ３１６製の導電性基板を設置し、対極として白金板を設置し、室温にて20mA/cm2の定電流で1時間電解酸化重合を行い、作用極上にポリアニリンを電析させた。得られたポリアニリン膜をイオン交換水で十分に洗浄した後、100℃で乾燥し、基板−ポリアニリン複合体を得た。ＳＥＭで観察したところ、直径が100〜300nmのフィブリル状ポリアニリンが絡み合ったような状態で得られていることが確認された。 (Example 1)
<Production of metal-supported carbon fiber-substrate composite>
In an acidic aqueous solution containing aniline monomer 0.5 mol / L and H 2 SO 4 1.0 mol / L, a conductive substrate made of SUS316 is installed as a working electrode, a platinum plate is installed as a counter electrode, and 20 mA / cm at room temperature. Electrolytic oxidation polymerization was carried out at a constant current of 2 for 1 hour to deposit polyaniline on the working electrode. The obtained polyaniline film was sufficiently washed with ion exchange water and then dried at 100 ° C. to obtain a substrate-polyaniline complex. When observed by SEM, it was confirmed that fibrillar polyaniline having a diameter of 100 to 300 nm was obtained in an intertwined state.

得られた基板−ポリアニリン複合体をＡｒ雰囲気中7℃/分の昇温速度で900℃まで加熱し、更に900℃で1時間保持して焼成処理を行った。得られた焼成物をＳＥＭで観察したところ、直径が50〜200nmで、焼成処理前とほぼ同様な形状の炭素繊維が得られていることが確認された。   The obtained substrate-polyaniline complex was heated to 900 ° C. at a rate of temperature increase of 7 ° C./min in an Ar atmosphere, and further held at 900 ° C. for 1 hour to perform a firing treatment. When the obtained fired product was observed with an SEM, it was confirmed that carbon fibers having a diameter of 50 to 200 nm and a shape similar to that before the firing treatment were obtained.

上記で得られた基板−炭素繊維複合体を一般的な触媒化プロセス後、硫酸銅メッキ浴にて無電解銅メッキを行い、0.5〜1mg/cm2の付着量で、炭素繊維を銅で被覆した。 After the substrate-carbon fiber composite obtained above is subjected to a general catalytic process, electroless copper plating is performed in a copper sulfate plating bath, and the carbon fiber is coated with copper with an adhesion amount of 0.5 to 1 mg / cm 2. did.

次に、アルカンスルホン酸第一スズ溶液（Ｓｎ2+：18g/L）に浸漬し、10mA/cm2の定電流で電解メッキを行い、スズを微粒子として2.4mg/cm2担持させ、銅を下地メッキとしたスズ担持炭素繊維−基板複合体を得た。得られたスズ担持炭素繊維−基板複合体をＳＥＭで観察したところ、図２に示すように、直径が60〜500nmで金属被覆されたフィブリル状の構造体が得られていることが確認できた。 Next, it is immersed in stannous alkane sulfonate solution (Sn 2+ : 18 g / L), electroplated at a constant current of 10 mA / cm 2 , tin is supported as 2.4 μg / cm 2 as fine particles, and copper is added. A tin-supported carbon fiber-substrate composite was obtained as a base plating. When the obtained tin-supporting carbon fiber-substrate composite was observed with an SEM, it was confirmed that a fibrillar structure having a metal coating with a diameter of 60 to 500 nm was obtained as shown in FIG. .

＜リチウムイオン電池用負極の評価＞
次に、上記のようにして得られたスズ担持炭素繊維−基板複合体を16mmφのサイズに打ち抜き、負極を作製した。この負極を用いて、リチウムメタルを正極とするハーフセルを組み立て、高速充放電試験を行った。なお、電解液としては、エチレンカーボネート（ＥＣ）及びエチルメチルカーボネート（ＥＭＣ）の混合溶媒（ＥＣ／ＥＭＣ体積比＝１／２）に、ＬｉＰＦ6（支持塩）を1.0Ｍ（mol/L）の濃度で溶解させた非水電解液を使用した。また、高速充放電試験において、充電は、0.5mA、5mA、10mAの各定電流で充電後、定電圧で5分間保持して行い、放電は、0.5mA、5mA、10mAの各定電流で放電し、下限電圧を1.5Ｖとした。0.5mAで充放電を繰り返し、10サイクル後の放電容量を電極の体積で除した値を0.5mA充放電時の比容量とした。また、10mAで充放電を4サイクル繰り返し、その平均放電容量を電極の体積で除した値を10mA高速充放電時の比容量とした。 <Evaluation of negative electrode for lithium ion battery>
Next, the tin-supported carbon fiber-substrate composite obtained as described above was punched out to a size of 16 mmφ to produce a negative electrode. Using this negative electrode, a half cell having lithium metal as the positive electrode was assembled, and a high-speed charge / discharge test was conducted. As an electrolytic solution, a mixed solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (EC / EMC volume ratio = 1/2) and LiPF 6 (supporting salt) of 1.0 M (mol / L) are used. A non-aqueous electrolyte dissolved in a concentration was used. In the high-speed charge / discharge test, charging is performed at a constant current of 0.5 mA, 5 mA, and 10 mA and then held at a constant voltage for 5 minutes. Discharging is performed at a constant current of 0.5 mA, 5 mA, and 10 mA. The lower limit voltage was 1.5V. Charge / discharge was repeated at 0.5 mA, and the value obtained by dividing the discharge capacity after 10 cycles by the volume of the electrode was taken as the specific capacity at 0.5 mA charge / discharge. Further, charging / discharging was repeated 4 cycles at 10 mA, and the value obtained by dividing the average discharge capacity by the volume of the electrode was taken as the specific capacity at 10 mA high-speed charging / discharging.

（実施例２）
スズの担持量を3.0mg/cm2とする以外は、実施例１と同様にして、銅を下地メッキとしたスズ担持炭素繊維−基板複合体を得た。得られたスズ担持炭素繊維−基板複合体をＳＥＭで観察したところ、図３に示すように、直径が60〜500nmで金属被覆されたフィブリル状の構造体が得られていることが確認できた。また、得られたスズ担持炭素繊維−基板複合体を用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Example 2)
A tin-supported carbon fiber-substrate composite having copper as a base plating was obtained in the same manner as in Example 1 except that the amount of tin supported was 3.0 mg / cm 2 . When the obtained tin-supported carbon fiber-substrate composite was observed with an SEM, it was confirmed that a fibrillar structure having a metal coating with a diameter of 60 to 500 nm was obtained as shown in FIG. . Further, using the obtained tin-supported carbon fiber-substrate composite, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

（実施例３）
スズの担持量を4.8mg/cm2とする以外は、実施例１と同様にして、銅を下地メッキとしたスズ担持炭素繊維−基板複合体を得た。得られたスズ担持炭素繊維−基板複合体をＳＥＭで観察したところ、図４に示すように、直径が60〜500nmで金属被覆されたフィブリル状の構造体が得られていることが確認できた。また、得られたスズ担持炭素繊維−基板複合体を用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Example 3)
A tin-supported carbon fiber-substrate composite having copper as a base plating was obtained in the same manner as in Example 1 except that the amount of tin supported was 4.8 mg / cm 2 . When the obtained tin-supporting carbon fiber-substrate composite was observed with an SEM, it was confirmed that a fibrillar structure having a metal coating with a diameter of 60 to 500 nm was obtained as shown in FIG. . Further, using the obtained tin-supported carbon fiber-substrate composite, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

（比較例１）
ソフトカーボン（メソフェーズカーボンマイクロビーズ：ＭＣＭＢ）8.5gと、導電助剤としての熱処理アセチレンブラック0.5gと、バインダーとしてのポリフッ化ビニリデン（ＰＶＤＦ）1gとを混合し、Ｎ-メチルピロリドン6.5gを添加した後、混練してペーストを得た。得られたペーストをドクターブレード法により厚さ20μmの銅箔上に150μmの厚さで塗布した。その後、150℃のオーブン中で3分間乾燥し、負極を作製した。こうして得られた負極を用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Comparative Example 1)
Soft carbon (mesophase carbon microbeads: MCMB) 8.5 g, heat-treated acetylene black 0.5 g as a conductive additive, and polyvinylidene fluoride (PVDF) 1 g as a binder were mixed, and N-methylpyrrolidone 6.5 g was added. Thereafter, kneading was performed to obtain a paste. The obtained paste was applied to a thickness of 150 μm on a 20 μm thick copper foil by a doctor blade method. Then, it dried for 3 minutes in 150 degreeC oven, and produced the negative electrode. Using the negative electrode thus obtained, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

（比較例２）
実施例１と同様にして作製した基板−炭素繊維複合体を負極に用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Comparative Example 2)
Using the substrate-carbon fiber composite produced in the same manner as in Example 1 as a negative electrode, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

（比較例３）
実施例１と同様にして作製した基板−炭素繊維複合体をアルカンスルホン酸第一スズ溶液（Ｓｎ2+：18g/L）に浸漬し、10mA/cm2の定電流で電解メッキを行い、スズを微粒子として5.36mg/cm2担持させ、スズ担持炭素繊維−基板複合体を得た。得られたスズ担持炭素繊維−基板複合体をＳＥＭで観察したところ、図５に示すように、直径が60〜500nmで金属被覆されたフィブリル状の構造体が得られていることが確認できた。また、得られたスズ担持炭素繊維−基板複合体を用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Comparative Example 3)
A substrate-carbon fiber composite produced in the same manner as in Example 1 was immersed in a stannous alkane sulfonate solution (Sn 2+ : 18 g / L) and subjected to electrolytic plating at a constant current of 10 mA / cm 2. Was supported as fine particles at 5.36 mg / cm 2 to obtain a tin-supported carbon fiber-substrate composite. When the obtained tin-supported carbon fiber-substrate composite was observed with an SEM, it was confirmed that a fibrillar structure having a metal coating with a diameter of 60 to 500 nm was obtained as shown in FIG. . Further, using the obtained tin-supported carbon fiber-substrate composite, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

（比較例４）
基板として厚さ20μmの電解銅箔［古河サーキットフォイル社製］を用いて、一般的な脱脂・酸洗工程後に、実施例１と同様にして10mA/cm2の定電流でスズメッキを行い、20mg/cm2のスズを銅箔上に析出させた。得られたスズメッキ銅箔のＳＥＭ写真を図６に示す。該ＳＥＭ写真からスズが銅箔上に密にメッキされていることが確認された。こうして得られた負極を用いて、実施例１と同様にしてハーフセルを組み立て、高速充放電試験を行った。 (Comparative Example 4)
Using an electrolytic copper foil (made by Furukawa Circuit Foil Co., Ltd.) having a thickness of 20 μm as a substrate, tin plating is performed at a constant current of 10 mA / cm 2 in the same manner as in Example 1 after a general degreasing and pickling process, and 20 mg / cm 2 of tin was deposited on the copper foil. The SEM photograph of the obtained tin plating copper foil is shown in FIG. From the SEM photograph, it was confirmed that tin was densely plated on the copper foil. Using the negative electrode thus obtained, a half cell was assembled in the same manner as in Example 1, and a high-speed charge / discharge test was performed.

以上の結果を図７に示す。図７から、比較例１〜４のハーフセルに比べて、実施例１〜４のハーフセルは、高容量で且つ優れた高速充放電特性を有することが確認できる。   The above results are shown in FIG. From FIG. 7, it can confirm that the half cell of Examples 1-4 has a high capacity | capacitance and the outstanding high-speed charge / discharge characteristic compared with the half cell of Comparative Examples 1-4.

本発明のリチウムイオン電池用負極の製造方法の工程図である。It is process drawing of the manufacturing method of the negative electrode for lithium ion batteries of this invention. 実施例１で得られた、銅を下地メッキとしたスズ担持炭素繊維−基板複合体のＳＥＭ写真である。2 is an SEM photograph of a tin-supported carbon fiber-substrate composite obtained in Example 1 and using copper as a base plating. 実施例２で得られた、銅を下地メッキとしたスズ担持炭素繊維−基板複合体のＳＥＭ写真である。4 is a SEM photograph of a tin-supported carbon fiber-substrate composite obtained in Example 2 with copper as a base plating. 実施例３で得られた、銅を下地メッキとしたスズ担持炭素繊維−基板複合体のＳＥＭ写真である。It is a SEM photograph of the tin carrying | support carbon fiber-substrate composite_body | complex obtained by Example 3 which used copper as base plating. 比較例３で得られた、スズ担持炭素繊維−基板複合体のＳＥＭ写真である。4 is a SEM photograph of a tin-supported carbon fiber-substrate composite obtained in Comparative Example 3. 比較例４で得られた、スズメッキされた銅箔のＳＥＭ写真である。4 is a SEM photograph of a tin-plated copper foil obtained in Comparative Example 4. 実施例１〜３及び比較例１〜４のハーフセルに対する高速充放電試験の結果を示す散布図である。It is a scatter diagram which shows the result of the high-speed charging / discharging test with respect to the half cell of Examples 1-3 and Comparative Examples 1-4.

符号の説明Explanation of symbols

１ 導電性基板
２ 炭素繊維
３ 導電性金属
４ リチウムを吸蔵・脱離可能な金属微粒子 DESCRIPTION OF SYMBOLS 1 Conductive substrate 2 Carbon fiber 3 Conductive metal 4 Metal fine particle which can occlude / release lithium

Claims (4)

導電性基板と、該導電性基板上に形成された炭素繊維と、該炭素繊維を被覆する導電性金属と、該導電性金属上に担持されたリチウムを吸蔵・脱離可能な金属微粒子とからなるリチウムイオン電池用負極の製造方法であって、
(i)導電性基板上において、芳香環を有する化合物を電解酸化重合してフィブリル状ポリマーを生成させる工程と、
(ii)該フィブリル状ポリマーを焼成して導電性基板上に炭素繊維を生成させる工程と、
(iii)該炭素繊維を導電性金属で被覆する工程と、
(iv)該導電性金属上にリチウムを吸蔵・脱離可能な金属微粒子を担持する工程と
を含むことを特徴とするリチウムイオン電池用負極の製造方法。 From a conductive substrate, a carbon fiber formed on the conductive substrate, a conductive metal covering the carbon fiber, and metal fine particles capable of inserting and extracting lithium supported on the conductive metal A method for producing a negative electrode for a lithium ion battery comprising:
(i) a step of electrolytically oxidatively polymerizing a compound having an aromatic ring on a conductive substrate to produce a fibrillated polymer;
(ii) firing the fibrillated polymer to form carbon fibers on a conductive substrate;
(iii) coating the carbon fiber with a conductive metal;
and (iv) carrying a metal fine particle capable of inserting and extracting lithium on the conductive metal. 前記炭素繊維を被覆する導電性金属がＣｕであることを特徴とする請求項１に記載のリチウムイオン電池用負極の製造方法。   2. The method for producing a negative electrode for a lithium ion battery according to claim 1, wherein the conductive metal covering the carbon fiber is Cu. 前記リチウムを吸蔵・脱離可能な金属微粒子がＳｎ微粒子であることを特徴とする請求項１に記載のリチウムイオン電池用負極の製造方法。   The method for producing a negative electrode for a lithium ion battery according to claim 1, wherein the metal fine particles capable of inserting and extracting lithium are Sn fine particles. 請求項１〜３のいずれかに記載の方法で製造したリチウムイオン電池用負極を具えたリチウムイオン電池。   The lithium ion battery provided with the negative electrode for lithium ion batteries manufactured by the method in any one of Claims 1-3.
JP2007030824A 2007-02-09 2007-02-09 Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery Withdrawn JP2008198427A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007030824A JP2008198427A (en) 2007-02-09 2007-02-09 Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007030824A JP2008198427A (en) 2007-02-09 2007-02-09 Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery

Publications (1)

Publication Number Publication Date
JP2008198427A true JP2008198427A (en) 2008-08-28

Family

ID=39757177

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007030824A Withdrawn JP2008198427A (en) 2007-02-09 2007-02-09 Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery

Country Status (1)

Country Link
JP (1) JP2008198427A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101238082B1 (en) 2010-12-24 2013-02-27 부산대학교 산학협력단 Foamed Nano Structure And Electrode Using It And Manufacturing Method Thereof
JP2016009556A (en) * 2014-06-24 2016-01-18 日立造船株式会社 Secondary battery electrode

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101238082B1 (en) 2010-12-24 2013-02-27 부산대학교 산학협력단 Foamed Nano Structure And Electrode Using It And Manufacturing Method Thereof
JP2016009556A (en) * 2014-06-24 2016-01-18 日立造船株式会社 Secondary battery electrode

Similar Documents

Publication Publication Date Title
EP3422444B1 (en) Anode for lithium secondary battery comprising mesh-shaped insulating layer, and lithium secondary battery comprising same
US10897040B2 (en) Anode having double-protection layer formed thereon for lithium secondary battery, and lithium secondary battery comprising same
EP3429014B1 (en) Lithium secondary battery having lithium metal formed on cathode and manufacturing method therefor
CN112313819B (en) Method of manufacturing negative electrode for lithium secondary battery and method of manufacturing lithium secondary battery
KR100454030B1 (en) Positive electrode for lithium-sulfur battery, method of preparing same, and lithium-sulfur battery comprising same
JP3702318B2 (en) Non-aqueous electrolyte battery electrode and non-aqueous electrolyte battery using the electrode
RU2619266C1 (en) Positive electrode for lithium-air battery and method of its preparation
JP2007042601A (en) Carbon electrode, production method therefor and nonaqueous electrolyte secondary battery
JP4088755B2 (en) Nonaqueous electrolyte secondary battery
KR20100051711A (en) Electrode body, and lithium secondary battery employing the electrode body
KR20200044231A (en) Negative electrode for lithium secondary battery, lithium secondary batter comprsing the same, and methoe for preparing thereof
KR20190129767A (en) Lithium metal secondary battery with improved safety and including the same
JP2016076342A (en) Electrode for nonaqueous secondary battery, and nonaqueous secondary battery
JP2008066128A (en) Negative electrode active material for lithium ion battery, and its manufacturing method, cathode for lithium ion battery, and lithium ion battery
CN112216875B (en) Lithium ion battery repeating unit, lithium ion battery, using method of lithium ion battery, battery module and automobile
JP2007042602A (en) Polymer battery
KR20190065153A (en) Method of Preparing Electrode for Secondary Battery
KR20190091220A (en) An anode for a lithium secondary battery and a battery comprising the same
JP2007018794A (en) Carbon material electrode, its manufacturing method and nonaqueous electrolyte secondary battery
CN113994512A (en) Lithium secondary battery and method for manufacturing the same
JP3968772B2 (en) Non-aqueous electrolyte battery
JP2007042603A (en) Nonaqueous electrolyte secondary battery
JP4114259B2 (en) Electrolyte for lithium secondary battery and lithium secondary battery using the same
JP2008198427A (en) Manufacturing method of negative electrode for lithium ion battery, and lithium ion battery
JP2009181827A (en) Method of manufacturing negative electrode for lithium-ion battery, and lithium-ion battery

Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20100511