JP5554932B2 - Non-aqueous lithium storage element - Google Patents

Non-aqueous lithium storage element Download PDF

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JP5554932B2
JP5554932B2 JP2009048061A JP2009048061A JP5554932B2 JP 5554932 B2 JP5554932 B2 JP 5554932B2 JP 2009048061 A JP2009048061 A JP 2009048061A JP 2009048061 A JP2009048061 A JP 2009048061A JP 5554932 B2 JP5554932 B2 JP 5554932B2
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宣宏 岡田
敏男 津端
均 森田
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    • HELECTRICITY
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    • H01GCAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
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    • H01G11/04Hybrid capacitors
    • H01G11/06Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • HELECTRICITY
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    • HELECTRICITY
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    • H01G11/00Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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    • H01G11/00Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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    • H01GCAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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    • H01ELECTRIC ELEMENTS
    • H01GCAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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Description

本発明は、非水系リチウム型蓄電素子に関する。   The present invention relates to a non-aqueous lithium storage element.

近年、地球環境の保全や省資源を目指したエネルギーの有効利用の観点から、深夜電力貯蔵システム、太陽光発電技術に基づく家庭用分散型蓄電システム、電気自動車用の蓄電システムなどが注目を集めている。
これらの蓄電システムにおける第一の要求事項は、用いられる蓄電素子のエネルギー密度が高いことである。この様な要求に対応可能な高エネルギー密度電池の有力候補として、リチウムイオン電池の開発が精力的に進められている。
In recent years, midnight power storage systems, home-use distributed power storage systems based on solar power generation technology, and power storage systems for electric vehicles have attracted attention from the viewpoint of global energy conservation and effective use of energy for resource conservation. Yes.
The first requirement in these power storage systems is that the energy density of the power storage elements used is high. As a promising candidate for a high energy density battery capable of meeting such demands, development of a lithium ion battery has been vigorously advanced.

第二の要求事項は、出力特性が高いことである。例えば、高効率エンジンと蓄電システムとの組み合わせ(例えば、ハイブリッド電気自動車)、又は燃料電池と蓄電システムとの組み合わせ(例えば、燃料電池電気自動車)において、加速時には蓄電システムにおける高出力放電特性が要求されている。
現在、高出力蓄電素子としては、電極に活性炭を用いた電気二重層キャパシタ(以下、単に「キャパシタ」ともいう。)が開発されており、耐久性(サイクル特性、高温保存特性)が高く、0.5〜1kW/L程度の出力特性を有する。これら電気二重層キャパシタは、上記高出力が要求される分野で最適の蓄電素子と考えられてきたが、そのエネルギー密度は、1〜5Wh/L程度に過ぎず、実用化には出力持続時間が足枷となっている。
The second requirement is high output characteristics. For example, a combination of a high-efficiency engine and a power storage system (for example, a hybrid electric vehicle) or a combination of a fuel cell and a power storage system (for example, a fuel cell electric vehicle) requires high output discharge characteristics in the power storage system during acceleration. ing.
Currently, an electric double layer capacitor using activated carbon as an electrode (hereinafter also simply referred to as a “capacitor”) has been developed as a high-power storage element, and has high durability (cycle characteristics and high-temperature storage characteristics). It has an output characteristic of about 5 to 1 kW / L. These electric double layer capacitors have been considered as the most suitable power storage elements in the field where the above high output is required, but the energy density is only about 1 to 5 Wh / L, and the output duration time is not practical. It is a footpad.

一方、現在ハイブリッド電気自動車で採用されているニッケル水素電池は、電気二重層キャパシタと同等の高出力を実現し、かつ160Wh/L程度のエネルギー密度を有している。しかしながら、そのエネルギー密度、出力をより一層高めるとともに、高温での安定性をさらに改善し、耐久性を高めるための研究が精力的に進められている。
また、リチウムイオン電池においても、高出力化に向けての研究が進められている。例えば、放電深度(素子の放電容量の何%を放電した状態かをあらわす値)50%において3kW/Lを超える高出力が得られるリチウムイオン電池が開発されているが、そのエネルギー密度は、100Wh/L以下であり、リチウムイオン電池の最大の特徴である高エネルギー密度を敢えて抑制した設計となっている。また、その耐久性(サイクル特性、高温保存特性)については電気ニ重層キャパシタに比べ劣る。そのため、実用的な耐久性を持たせるためには放電深度が0〜100%の範囲よりも狭い範囲でしか使用することができない。そのため実際に使用できる容量はさらに小さくなり、耐久性をより一層向上させるための研究が精力的に進められている。
On the other hand, nickel-metal hydride batteries currently used in hybrid electric vehicles realize high output equivalent to electric double layer capacitors and have an energy density of about 160 Wh / L. However, research is underway energetically to further increase the energy density and output, further improve the stability at high temperatures, and enhance the durability.
In addition, research for higher output is also being conducted in lithium ion batteries. For example, a lithium ion battery has been developed that can obtain a high output exceeding 3 kW / L at a discharge depth (a value representing what percentage of the device discharge capacity is discharged) 50%, and its energy density is 100 Wh. / L or less, and a design that dares to suppress the high energy density, which is the greatest feature of the lithium ion battery. Further, its durability (cycle characteristics, high temperature storage characteristics) is inferior to that of an electric double layer capacitor. Therefore, in order to give practical durability, the depth of discharge can be used only in a range narrower than the range of 0 to 100%. For this reason, the capacity that can be actually used is further reduced, and research for further improving the durability is being actively pursued.

上記の様に高出力密度、高エネルギー密度、耐久性を兼ね備えた蓄電素子の実用化が強く求められているが、上述した既存の蓄電素子には一長一短がある。そのため、これらの技術的要求を充足する新たな蓄電素子が求められており、有力な候補としてリチウムイオンキャパシタと呼ばれる蓄電素子の開発が近年盛んである。
リチウムイオンキャパシタは、リチウムイオンを含有した電解質を含む非水系電解液を使用する蓄電素子(非水系リチウム型蓄電素子)であって、正極においては電気二重層キャパシタと同様の陰イオンの吸着・脱着による非ファラデー反応、負極においてはリチウムイオン電池と同様のリチウムイオンの吸蔵・放出によるファラデー反応によって充放電を行う蓄電素子である。
As described above, there is a strong demand for practical use of a power storage device having high output density, high energy density, and durability. However, the existing power storage device described above has advantages and disadvantages. Therefore, a new power storage element that satisfies these technical requirements has been demanded, and development of a power storage element called a lithium ion capacitor has been actively developed as a promising candidate.
A lithium ion capacitor is a storage element that uses a non-aqueous electrolyte containing an electrolyte containing lithium ions (non-aqueous lithium type storage element), and the positive electrode adsorbs and desorbs the same as an electric double layer capacitor at the positive electrode. It is a power storage element that charges and discharges by a non-Faraday reaction due to Faraday reaction and a Faraday reaction by insertion and extraction of lithium ions in the negative electrode similar to a lithium ion battery.

上述のように、正極・負極の双方において非ファラデー反応による充放電を行う電気二重層キャパシタにおいては、出力特性に優れるがエネルギー密度が小さい。一方、正極・負極の双方においてファラデー反応による充放電を行う二次電池においては、エネルギー密度に優れるが、出力特性に劣る。リチウムイオンキャパシタは、正極では非ファラデー反応、負極ではファラデー反応による充放電を行うことによって、優れた出力特性と高いエネルギー密度の両立を狙う新たな蓄電素子である。
このようなリチウムイオンキャパシタとしては、正極活物質として活性炭を用い、負極活物質として、天然黒鉛又は人造黒鉛、黒鉛化メソフェーズカーボン小球体、黒鉛化メソフェーズカーボン繊維、黒鉛ウイスカ、黒鉛化炭素繊維等を用いた蓄電素子が提案されている(以下、特許文献1参照)。また、正極活物質として活性炭を用い、負極活物質として難黒鉛化炭素又は黒鉛を用いた蓄電素子が提案されている(以下、特許文献2参照)。
As described above, an electric double layer capacitor that charges and discharges by a non-Faraday reaction in both the positive electrode and the negative electrode has excellent output characteristics but low energy density. On the other hand, a secondary battery that charges and discharges by a Faraday reaction in both the positive electrode and the negative electrode is excellent in energy density but inferior in output characteristics. The lithium ion capacitor is a new power storage element that aims to achieve both excellent output characteristics and high energy density by performing charge and discharge by a non-Faraday reaction at the positive electrode and a Faraday reaction at the negative electrode.
As such a lithium ion capacitor, activated carbon is used as a positive electrode active material, and natural graphite or artificial graphite, graphitized mesophase carbon microspheres, graphitized mesophase carbon fiber, graphite whisker, graphitized carbon fiber, etc. are used as a negative electrode active material. A power storage element used has been proposed (see Patent Document 1 below). In addition, a power storage element using activated carbon as a positive electrode active material and non-graphitizable carbon or graphite as a negative electrode active material has been proposed (see Patent Document 2 below).

正極活物質として通常の活性炭と異なる水素/炭素が0.05〜0.5であり、BET比表面積が300〜2,000m/gであり、BJH法によるメソ孔容積が0.02〜0.3ml/gであり、MP法による全細孔容積が0.3〜1.0ml/gである細孔構造を有する炭化水素材料を用い、負極として黒鉛を除く光学的異方性炭素物質を賦活処理した材料を用いる蓄電素子も提案されている(以下、特許文献3参照)。
また、正極活物質として活性炭又は水素原子/炭素原子の原子数比率が0.05〜」0.50であるポリアセン系骨格構造を有するポリアセン系有機半導体を用い、負極材料として水素原子/炭素原子の原子数比率が0以上0.05未満である難黒鉛化性炭素を用いた蓄電素子も提案されている(以下、特許文献4参照)。
As a positive electrode active material, hydrogen / carbon different from normal activated carbon is 0.05 to 0.5, BET specific surface area is 300 to 2,000 m 2 / g, and mesopore volume by BJH method is 0.02 to 0. An optically anisotropic carbon material excluding graphite as a negative electrode using a hydrocarbon material having a pore structure of 3 ml / g and a total pore volume by the MP method of 0.3 to 1.0 ml / g A power storage element using an activated material has also been proposed (see Patent Document 3 below).
Further, activated carbon or a polyacene organic semiconductor having a polyacene skeleton structure with a hydrogen atom / carbon atom number ratio of 0.05 to 0.50 is used as the positive electrode active material, and hydrogen atoms / carbon atoms are used as the negative electrode material. A power storage element using non-graphitizable carbon having an atomic ratio of 0 or more and less than 0.05 has also been proposed (see Patent Document 4 below).

正極活物質として活性炭を用い、負極活物質として易黒鉛化炭素と難黒鉛化炭素とからなる炭素材料を用いた蓄電素子も提案されている(以下、特許文献5参照)。
リチウムイオンキャパシタの負極材料としては、活性炭の表面に炭素質材料を被着させた炭素質材料で、直径20Å以上500Å以下の細孔に由来するメソ孔量をVm1(cc/g)、直径20Å未満の細孔に由来するマイクロ孔量をVm2(cc/g)とする時、0.01≦Vm1≦0.20、かつ、0.01≦Vm2≦0.40を満足する蓄電素子用負極材料が提案されている(以下、特許文献6参照)。
An electric storage element using activated carbon as a positive electrode active material and a carbon material composed of graphitizable carbon and non-graphitizable carbon as a negative electrode active material has also been proposed (see Patent Document 5 below).
The negative electrode material of the lithium ion capacitor is a carbonaceous material obtained by depositing a carbonaceous material on the surface of activated carbon. The amount of mesopores derived from pores having a diameter of 20 to 500 mm is Vm1 (cc / g), and the diameter is 20 mm. A negative electrode material for a storage element satisfying 0.01 ≦ Vm1 ≦ 0.20 and 0.01 ≦ Vm2 ≦ 0.40 when the amount of micropores derived from pores smaller than Vm2 (cc / g) Has been proposed (see Patent Document 6 below).

特開平8−107048号公報Japanese Patent Laid-Open No. 8-1007048 特開平9−283383号公報JP-A-9-283383 特開2005−93778号公報JP 2005-93778 A 特開2007−115721号公報JP 2007-115721 A 特開2008−235169号公報JP 2008-235169A 特開2003−346801号公報JP 2003-346801 A

本発明者らが検討を行ったところ、上述の特許文献3に記載された蓄電素子は、エネルギー密度は大きいものの出力特性が十分ではないという課題を有していることがわかった。また、上述の特許文献4又は5に記載された蓄電素子は、高エネルギー密度及び高出力特性と高耐久性の両立という点においては十分ではない。また、上述の特許文献6に記載された蓄電素子は、充放電効率が高く出力特性に優れる一方で、耐久性を重視する用途においてはさらなる改良の余地があることが判明した。
本発明は、高エネルギー密度及び高出力密度に加え、高耐久性を兼ね揃えた蓄電素子を提供することを目的とする。
As a result of investigations by the present inventors, it has been found that the power storage element described in Patent Document 3 has a problem that the output characteristics are not sufficient although the energy density is large. In addition, the power storage element described in Patent Document 4 or 5 described above is not sufficient in terms of achieving both high energy density, high output characteristics, and high durability. In addition, the power storage device described in Patent Document 6 described above has high charge / discharge efficiency and excellent output characteristics, but it has been found that there is room for further improvement in applications in which durability is important.
An object of this invention is to provide the electrical storage element which has high durability in addition to high energy density and high output density.

本発明者らは、前記課題を解決するため鋭意研究を重ねた結果、非水系リチウム型蓄電素子において、特定の細孔構造を有する活性炭を正極活物質として使用し、更に低比表面積の難黒鉛化性炭素材料を負極活物質として使用することにより、予想外に、該蓄電素子が高いエネルギー密度及び出力密度を維持したまま、耐久性を飛躍的に向上できることを見出し、本発明を完成するに至った。
すなわち、本発明は、下記のとおりである。
As a result of intensive studies to solve the above-mentioned problems, the present inventors have used non-aqueous lithium-type energy storage devices that use activated carbon having a specific pore structure as a positive electrode active material, and further have a low specific surface area of non-graphite. Unexpectedly, by using the carbonizable carbon material as the negative electrode active material, it was found that the electricity storage device can dramatically improve the durability while maintaining a high energy density and output density, and the present invention is completed. It came.
That is, the present invention is as follows.

[1]負極集電体に負極活物質層を設けた負極電極体、正極集電体に正極活物質層を設けた正極電極体、及びセパレータを積層してなる電極積層体、並びにリチウムイオンを含有した電解質を含む非水系電解液を外装体に収納してなる非水系リチウム型蓄電素子であって、該正極活物質が活性炭を主成分とし含み、ここで、該活性炭は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をV1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をV2(cc/g)とする時、0.3<V1≦0.8、かつ、0.5≦V2≦1.0を満足し、BET法により測定される比表面積が1,500m/g以上3,000m/g以下であり、そして該負極活物質が、BET法により測定される比表面積が1m/g以上200m/g未満である難黒鉛化性炭素材料を主成分として含むことを特徴とする非水系リチウム型蓄電素子。 [1] A negative electrode body in which a negative electrode active material layer is provided on a negative electrode current collector, a positive electrode body in which a positive electrode current collector is provided with a positive electrode active material layer, an electrode laminate formed by laminating a separator, and lithium ions A non-aqueous lithium-type energy storage device in which a non-aqueous electrolyte solution containing a contained electrolyte is housed in an exterior body, wherein the positive electrode active material contains activated carbon as a main component, where the activated carbon is calculated by the BJH method When the amount of mesopores derived from pores having a diameter of 20 to 500 mm is V1 (cc / g) and the amount of micropores derived from pores of less than 20 mm calculated by the MP method is V2 (cc / g) 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0, and the specific surface area measured by the BET method is 1,500 m 2 / g or more and 3,000 m 2 / g or less. And the negative electrode active material is obtained by the BET method. A non-aqueous lithium-type energy storage device comprising a non-graphitizable carbon material having a measured specific surface area of 1 m 2 / g or more and less than 200 m 2 / g as a main component.

[2]X線広角回折法で得られる前記難黒鉛化性炭素材料の(002)面の面間隔が0.341nm以上0.390nm以下である、前記[1]に記載の非水系リチウム型蓄電素子。   [2] The non-aqueous lithium-type electricity storage device according to [1], wherein the non-graphitizable carbon material obtained by X-ray wide angle diffraction method has a (002) plane spacing of 0.341 nm to 0.390 nm. element.

[3]前記難黒鉛化性炭素材料は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をVm1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をVm2(cc/g)とする時、0.001≦Vm1<0.01、かつ、0.001≦Vm2<0.01を満足する炭素材料である、前記[1]又は[2]に記載の非水系リチウム型蓄電素子。   [3] The non-graphitizable carbon material has a mesopore amount derived from pores having a diameter of 20 to 500 mm calculated by the BJH method as Vm1 (cc / g) and a pore having a diameter of less than 20 mm calculated by the MP method. [1], which is a carbon material satisfying 0.001 ≦ Vm1 <0.01 and 0.001 ≦ Vm2 <0.01 when the amount of micropores derived from is Vm2 (cc / g) Or the non-aqueous lithium-type electrical storage element as described in [2].

[4]前記難黒鉛化性炭素材料の平均粒径が5〜30μmである、前記[1]〜[3]のいずれかに記載の非水系リチウム型蓄電素子。   [4] The non-aqueous lithium storage element according to any one of [1] to [3], wherein the non-graphitizable carbon material has an average particle size of 5 to 30 μm.

本願発明により、高エネルギー密度及び高出力密度に加え、高耐久性を兼ね揃えた非水系リチウム型蓄電素子が提供される。   According to the present invention, there is provided a non-aqueous lithium storage element that has both high energy density and high output density, as well as high durability.

以下、本発明の実施の形態につき詳細に説明する。
本発明は、負極集電体に負極活物質層を設けた負極電極体、正極集電体に正極活物質層を設けた正極電極体、及びセパレータを積層してなる電極積層体、並びにリチウムイオンを含有した電解質を含む非水系電解液を外装体に収納してなる非水系リチウム型蓄電素子であって、該正極活物質が活性炭を主成分として含み、ここで、該活性炭は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をV1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をV2(cc/g)とする時、0.3<V1≦0.8、かつ、0.5≦V2≦1.0を満足し、BET法により測定される比表面積が1,500m/g以上3,000m/g以下であり、そして該負極活物質が、BET法により測定される比表面積が1m/g以上200m/g未満である難黒鉛化性炭素材料を主成分として含むことを特徴とする。
Hereinafter, embodiments of the present invention will be described in detail.
The present invention relates to a negative electrode body in which a negative electrode active material layer is provided on a negative electrode current collector, a positive electrode body in which a positive electrode current collector is provided with a positive electrode active material layer, an electrode laminate in which a separator is laminated, and lithium ions A non-aqueous lithium-type electricity storage element in which a non-aqueous electrolyte solution containing an electrolyte containing is contained in an exterior body, wherein the positive electrode active material contains activated carbon as a main component, wherein the activated carbon is obtained by a BJH method. The amount of mesopores derived from the calculated pores having a diameter of 20 to 500 mm is V1 (cc / g), and the amount of micropores derived from the pores having a diameter of less than 20 mm calculated by the MP method is V2 (cc / g). When satisfying 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0, the specific surface area measured by the BET method is 1,500 m 2 / g or more and 3,000 m 2 / g or less. And the negative electrode active material is a BET method. It includes a non-graphitizable carbon material having a specific surface area of 1 m 2 / g or more and less than 200 m 2 / g as a main component.

まず、本発明の蓄電素子における正極活物質について説明する。
本発明において、正極活物質は、活性炭を主成分として含み、ここで、該活性炭は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をV1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をV2(cc/g)とする時、0.3<V1≦0.8、かつ、0.5≦V2≦1.0を満足し、BET法により測定される比表面積が1,500m/g以上3,000m/g以下であることを特徴とする。ここで、主成分として含むとは、正極活物質の総重量を100%とする時に50%より多い量を含むことを意味する。
First, the positive electrode active material in the electricity storage device of the present invention will be described.
In the present invention, the positive electrode active material contains activated carbon as a main component. Here, the activated carbon has a mesopore amount derived from pores having a diameter of 20 mm or more and 500 mm or less calculated by the BJH method as V1 (cc / g), When the amount of micropores derived from pores having a diameter of less than 20 mm calculated by the MP method is V2 (cc / g), 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 The specific surface area measured by the BET method is 1,500 m 2 / g or more and 3,000 m 2 / g or less. Here, including as a main component means including more than 50% when the total weight of the positive electrode active material is 100%.

上記活性炭の原料として用いられる炭素質材料としては、通常活性炭原料として用いられる炭素源であれば特に限定されるものではなく、例えば、木材、木粉、ヤシ殻、パルプ製造時の副産物、バカス、廃糖蜜などの植物系原料;泥炭、亜炭、褐炭、瀝青炭、無煙炭、石油蒸留残渣成分、石油ピッチ、コークス、コールタールなどの化石系原料;フェノール樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、メラミン樹脂、尿素樹脂、レゾルシノール樹脂、セルロイド、エポキシ樹脂、ポリウレタン樹脂、ポリエステル樹脂、ポリアミド樹脂などの各種合成樹脂;ポリブチレン、ポリブタジエン、ポリクロロプレンなどの合成ゴム;その他合成木材、合成パルプなど、あるいはそれらの炭化物が挙げられる。これらの原料の中でも、ヤシ殻、木粉などの植物系原料、又はそれらの炭化物が好ましく、ヤシ殻炭化物が特に好ましい。
これらの原料を上記活性炭とするための炭化、賦活方式として、例えば固定床方式、移動床方式、流動床方式、スラリー方式、ロータリーキルン方式などの公知の方式を採用できる。
The carbonaceous material used as a raw material for the activated carbon is not particularly limited as long as it is a carbon source that is usually used as a raw material for activated carbon. For example, wood, wood flour, coconut shell, by-product during pulp production, bacus, Plant raw materials such as waste molasses; Fossil raw materials such as peat, lignite, lignite, bituminous coal, anthracite, petroleum distillation residue components, petroleum pitch, coke, coal tar; phenol resin, vinyl chloride resin, vinyl acetate resin, melamine resin, Various synthetic resins such as urea resin, resorcinol resin, celluloid, epoxy resin, polyurethane resin, polyester resin, polyamide resin; synthetic rubber such as polybutylene, polybutadiene, polychloroprene; other synthetic wood, synthetic pulp, or their carbides It is done. Among these raw materials, plant raw materials such as coconut shells and wood flour, or carbides thereof are preferable, and coconut shell carbides are particularly preferable.
As a carbonization and activation method for using these raw materials as the activated carbon, known methods such as a fixed bed method, a moving bed method, a fluidized bed method, a slurry method, and a rotary kiln method can be employed.

これらの原料の炭化方法としては、窒素、二酸化炭素、ヘリウム、アルゴン、キセノン、ネオン、一酸化炭素、燃焼排ガスなどの不活性ガス、あるいはこれらの不活性ガスを主成分とした他のガスとの混合ガスを使用して、400〜700℃(特に450〜600℃)程度で30分〜10時間程度焼成する方法が挙げられる。
上記炭化方法により得られた炭化物の賦活方法としては、水蒸気、二酸化炭素、酸素などの賦活ガスを用いて焼成するガス賦活法が用いられる。このうち、賦活ガスとして、水蒸気又は二酸化炭素を使用する方法が好ましい。
Carbonization methods for these raw materials include inert gases such as nitrogen, carbon dioxide, helium, argon, xenon, neon, carbon monoxide and combustion exhaust gas, or other gases mainly composed of these inert gases. The method of baking for about 30 minutes to about 10 hours at about 400-700 degreeC (especially 450-600 degreeC) using mixed gas is mentioned.
As a method for activating the carbide obtained by the carbonization method, a gas activation method in which firing is performed using an activation gas such as water vapor, carbon dioxide, or oxygen is used. Among these, a method using water vapor or carbon dioxide as the activation gas is preferable.

この賦活方法では、賦活ガスを0.5〜3.0kg/h(特に0.7〜2.0kg/h)の割合で供給しながら、上記炭化物を3〜12時間(好ましくは5〜11時間、さらに好ましくは6〜10時間)かけて800〜1,000℃まで昇温して賦活するのが好ましい。
さらに、上記炭化物の賦活処理に先立ち、上記炭化物を予め1次賦活してもよい。この1次賦活では、通常、炭素質材料を水蒸気、二酸化炭素、酸素などの賦活ガスを用いて、900℃未満の温度で焼成してガス賦活すればよい。
上記炭化方法における焼成温度/時間と、上記賦活方法における賦活ガス供給量/昇温速度/最高賦活温度とを適宜組み合わせることにより、以下の特徴を有する本発明の活性炭を製造することができる。
In this activation method, the carbide is supplied for 3 to 12 hours (preferably 5 to 11 hours) while supplying the activation gas at a rate of 0.5 to 3.0 kg / h (particularly 0.7 to 2.0 kg / h). Further, it is preferable that the temperature is increased to 800 to 1,000 ° C. and activated over 6 to 10 hours).
Furthermore, prior to the activation treatment of the carbide, the carbide may be activated in advance. In this primary activation, the carbonaceous material is usually fired at a temperature of less than 900 ° C. using an activation gas such as water vapor, carbon dioxide, oxygen, etc. to activate the gas.
The activated carbon of the present invention having the following characteristics can be produced by appropriately combining the firing temperature / time in the carbonization method and the activation gas supply amount / temperature increase rate / maximum activation temperature in the activation method.

このようにして得られた活性炭は、本発明において以下の特徴を有することが好ましい。すなわち、活性炭のBJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をV1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をV2(cc/g)とする時、0.3<V1≦0.8、かつ、0.5≦V2≦1.0が満たされる。   The activated carbon thus obtained preferably has the following characteristics in the present invention. That is, the amount of mesopores derived from pores having a diameter of 20 to 500 mm calculated by the BJH method of activated carbon is V1 (cc / g), and the amount of micropores derived from pores having a diameter of less than 20 mm calculated by the MP method is V2. (Cc / g), 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 are satisfied.

蓄電素子に組み込んだときの出力特性を大きくする点で、メソ孔量V1が0.3g/ccより大きい値であることが好ましく、また、蓄電素子の容量の低下を抑える点から、0.8以下であることが好ましく、より好ましくは0.35g/cc以上0.7g/cc以下、さらに好ましくは、0.4g/cc以上0.6g/cc以下である。
一方、マイクロ孔量V2は、活性炭の比表面積を大きくし、容量を増加させるために、0.5g/cc以上であることが好ましく、また、活性炭の嵩を抑え、電極としての密度を増加し、単位体積当たりの容量を増加させるという点から、1.0g/cc以下であることが好ましく、より好ましくは、0.6g/cc以上1.0g/cc以下、さらに好ましくは、0.8g/cc以上1.0g/cc以下である。
The mesopore amount V1 is preferably a value larger than 0.3 g / cc from the viewpoint of increasing the output characteristics when incorporated in the storage element, and from the viewpoint of suppressing a decrease in the capacity of the storage element. Or less, more preferably 0.35 g / cc or more and 0.7 g / cc or less, and still more preferably 0.4 g / cc or more and 0.6 g / cc or less.
On the other hand, the micropore volume V2 is preferably 0.5 g / cc or more in order to increase the specific surface area of the activated carbon and increase the capacity, and also suppresses the bulk of the activated carbon and increases the density as an electrode. From the viewpoint of increasing the capacity per unit volume, it is preferably 1.0 g / cc or less, more preferably 0.6 g / cc or more and 1.0 g / cc or less, and still more preferably 0.8 g / cc. cc to 1.0 g / cc.

メソ孔量V1とマイクロ孔量V2は、0.3≦V1/V2≦0.9の範囲にあることが好ましい。マイクロ孔量に比べてメソ孔量が多く、容量を得ながら、出力特性の低下を抑えるという点から、V1/V2が0.3以上であることが好ましく、また、メソ孔量に比べてマイクロ孔量が多く、出力特性を得ながら、容量の低下を抑えるという点から、V1/V2は0.9以下であることが好ましく、より好ましい範囲は、0.4≦V1/V2≦0.7、さらに好ましい範囲は、0.55≦V1/V2≦0.7である。   The mesopore volume V1 and the micropore volume V2 are preferably in the range of 0.3 ≦ V1 / V2 ≦ 0.9. V1 / V2 is preferably 0.3 or more from the viewpoint that the amount of mesopores is larger than the amount of micropores and the reduction in output characteristics is suppressed while obtaining capacity, and the micropore size is smaller than that of mesopores. V1 / V2 is preferably 0.9 or less from the viewpoint that the amount of pores is large and output capacity is suppressed while obtaining output characteristics, and a more preferable range is 0.4 ≦ V1 / V2 ≦ 0.7. A more preferable range is 0.55 ≦ V1 / V2 ≦ 0.7.

本発明において、マイクロ孔量及びメソ孔量は以下のような方法により求めた値である。すなわち、試料を500℃で一昼夜真空乾燥を行い、窒素を吸着質とし吸脱着の等温線の測定を行なう。このときの脱着側の等温線を用いて、マイクロ孔量はMP法により、メソ孔量はBJH法により算出した。
MP法とは、「t−プロット法」(B.C.Lippens,J.H.de Boer,J.Catalysis,4319(1965))を利用して、マイクロ孔容積、マイクロ孔面積、およびマイクロ孔の分布を求める方法を意味し、M.Mikhail, Brunauer, Bodorにより考案された方法である(R.S.Mikhail,S.Brunauer,E.E.Bodor,J.Colloid Interface Sci., 26,45 (1968))。また、BJH法は一般的にメソ孔の解析に用いられる計算方法で、Barrett, Joyner, Halendaらにより提唱されたものである(E. P. Barrett, L. G. Joyner and P. Halenda, J. Amer. Chem. Soc., 73, 373(1951))。
In the present invention, the micropore volume and mesopore volume are values determined by the following method. That is, the sample is vacuum-dried at 500 ° C. all day and night, and adsorption and desorption isotherms are measured using nitrogen as an adsorbate. Using the isotherm on the desorption side at this time, the micropore volume was calculated by the MP method, and the mesopore volume was calculated by the BJH method.
The MP method uses a “t-plot method” (BC Lippens, JH de Boer, J. Catalysis, 4319 (1965)), and uses a micropore volume, a micropore area, and a micropore. Is a method for obtaining the distribution of M.M. It is a method devised by Mikhail, Brunauer, Bodor (RS Mikhal, S. Brunauer, EE Bodor, J. Colloid Interface Sci., 26, 45 (1968)). The BJH method is a calculation method generally used for analysis of mesopores and was proposed by Barrett, Joyner, Halenda et al. (EP Barrett, LG Joyner and P. Halenda, J Amer. Chem. Soc., 73, 373 (1951)).

正極活物質として使用される活性炭の平均細孔径は、出力を最大にする点から、17Å以上であることが好ましく、18Å以上であることがより好ましく、20Å以上であることが最も好ましい。また容量を最大にする点から、25Å以下であることが好ましい。本発明でいうところの平均細孔径とは、液体窒素温度における各相対圧力下での窒素ガスの各平衡吸着量を測定して得られる重量当たりの全細孔容積をBET比表面積で除して求めたものを意味する。   The average pore diameter of the activated carbon used as the positive electrode active material is preferably 17 mm or more, more preferably 18 mm or more, and most preferably 20 mm or more from the viewpoint of maximizing the output. Further, from the point of maximizing the capacity, it is preferably 25 mm or less. The average pore diameter referred to in the present invention is obtained by dividing the total pore volume per weight obtained by measuring each equilibrium adsorption amount of nitrogen gas under each relative pressure at the liquid nitrogen temperature by the BET specific surface area. It means what I asked for.

正極活物質として使用される活性炭は、そのBET比表面積が1,500m/g以上3,000m/g以下が好ましい。より好ましくは、1,500m/g以上2,500m/g以下である。BET比表面積が1,500m/g未満の場合には、十分なエネルギー密度が得られず、一方、BET比表面積が3,000m/gを超える場合には、バインダーを多量に入れないと十分な電極の強度を保てず体積当りの性能が低下する。
尚、正極活物質には、蓄電素子のエネルギー密度を向上させるという観点から、上記活性炭に加えて、リチウムイオン二次電池の正極活物質として公知のリチウムイオンを吸蔵放出する金属酸化物、例えば、コバルト酸リチウムを添加することも好ましい。正極活物質を活性炭とリチウムイオンを吸蔵放出する金属酸化物との混合物とする場合は、活性炭の全正極活物質に対する比率は、50重量%以上とすることが好ましい。
The activated carbon used as the positive electrode active material preferably has a BET specific surface area of 1,500 m 2 / g or more and 3,000 m 2 / g or less. More preferably not more than 1,500 m 2 / g or more 2,500 m 2 / g. When the BET specific surface area is less than 1,500 m 2 / g, sufficient energy density cannot be obtained. On the other hand, when the BET specific surface area exceeds 3,000 m 2 / g, a large amount of binder must be added. A sufficient electrode strength cannot be maintained, and the performance per volume is lowered.
In addition, from the viewpoint of improving the energy density of the electricity storage element, the positive electrode active material includes, in addition to the activated carbon, a metal oxide that occludes and releases lithium ions known as a positive electrode active material of a lithium ion secondary battery, for example, It is also preferable to add lithium cobaltate. When the positive electrode active material is a mixture of activated carbon and a metal oxide that occludes and releases lithium ions, the ratio of activated carbon to the total positive electrode active material is preferably 50% by weight or more.

次に、本発明の蓄電素子における負極活物質について説明する。
負極活物質は、BET法により測定される比表面積が1m/g以上200m/g未満である難黒鉛化性炭素材料を主成分として含むことを特徴とする。ここで、主成分として含むとは、負極活物質の総重量を100%とする時に50%より多い量を含むことを意味する。前述した特定の細孔構造を有する活性炭を正極活物質として使用し、更に負極活物質にBET法により測定される比表面積が1m/g以上200m/g未満である難黒鉛化性炭素材料を使用した本発明の蓄電素子は、正極活物質として活性炭を使用し負極活物質として活性炭の表面に炭素質材料を被着させた複合多孔性材料を使用した特許文献6に記載された蓄電素子に対して、高いエネルギー密度及び出力密度を維持したまま、耐久性を飛躍的に向上できる。
Next, the negative electrode active material in the electricity storage device of the present invention will be described.
The negative electrode active material includes a non-graphitizable carbon material having a specific surface area measured by the BET method of 1 m 2 / g or more and less than 200 m 2 / g as a main component. Here, including as a main component means including more than 50% when the total weight of the negative electrode active material is 100%. Specific activated carbon having a pore structure was used as a positive electrode active material, non-graphitizable carbon material is further 200m less than 2 / g specific surface area to be measured is 1 m 2 / g or more by the BET method to the negative electrode active material described above The power storage device of the present invention using the power storage device described in Patent Document 6 using a composite porous material in which activated carbon is used as a positive electrode active material and a carbonaceous material is deposited on the surface of the activated carbon as a negative electrode active material. On the other hand, durability can be dramatically improved while maintaining high energy density and power density.

上記理由は定かではないが、例えば、負極活物質に難黒鉛化性炭素材料を用いることで、上記記載の複合多孔性材料に比べ細孔が少ないため、負極材料と電解液との接触面積は小さく、その結果、自己放電やリーク電流を好適に防止できるためと考えられる。こういった理由により、特に低比表面積の難黒鉛化性炭素材料において、その効果は顕著である。   Although the reason for this is not clear, for example, by using a non-graphitizable carbon material for the negative electrode active material, since the number of pores is smaller than that of the composite porous material described above, the contact area between the negative electrode material and the electrolytic solution is As a result, it is considered that self-discharge and leakage current can be suitably prevented. For these reasons, the effect is particularly remarkable in a non-graphitizable carbon material having a low specific surface area.

本発明における難黒鉛化性炭素材料には、特に制限はないが、以下のものを好ましいものとして例示することができる。ナフタレン、アントラセンなどの低分子有機化合物;フェノール樹脂、フラン樹脂、フルフラール樹脂、セルロース系樹脂などの樹脂類;コールタールピッチ、酸素架橋石油ピッチ、石油又は石炭系ピッチなどのピッチ類などを原料とし、加熱又は焼成して得られる難黒鉛化性炭素材料などが挙げられる。ここで言う加熱又は焼成の方法は、公知の方法に従えばよい。例えば、上記原料を窒素などの不活性ガス雰囲気下中、500〜1200度程度の温度範囲で炭化することで得られる。
上記のように加熱又は焼成して得られたものをそのまま用いてもよいし、更に賦活などの処理で細孔容積を増加させたものを用いても構わない。
これらの難黒鉛化性炭素材料は単独で又は二種以上組み合わせて使用できる。
Although there is no restriction | limiting in particular in the non-graphitizable carbon material in this invention, The following can be illustrated as a preferable thing. Low molecular organic compounds such as naphthalene and anthracene; resins such as phenolic resin, furan resin, furfural resin, and cellulose resin; pitch materials such as coal tar pitch, oxygen-crosslinked petroleum pitch, petroleum or coal pitch, etc. Examples thereof include non-graphitizable carbon materials obtained by heating or baking. The method of heating or baking mentioned here may follow a known method. For example, it can be obtained by carbonizing the raw material in a temperature range of about 500 to 1200 degrees in an inert gas atmosphere such as nitrogen.
What was heated or baked as mentioned above may be used as it is, or further, the pore volume may be increased by a treatment such as activation.
These non-graphitizable carbon materials can be used alone or in combination of two or more.

本発明における難黒鉛化性炭素材料の比表面積は、BET法により測定される比表面積で1m/g以上200m/g未満であるものが好ましく、3〜100m/gであるものがより好ましく、4〜20m/gであるものが更に好ましい。
BET比表面積が1m/g未満の場合には、十分なエネルギー密度が得られない。一方、200m/g以上の場合には、耐久性が落ちることが判明した。その理由は定かではないが、例えば、BET比表面積の向上に伴い電解液との接触面積も向上することにより、リーク電流の増大や自己放電の増大が起きやすいためと考えられる。
The specific surface area of the non-graphitizable carbon material in the present invention preferably has less than 1 m 2 / g or more 200 meters 2 / g in specific surface area measured by BET method, and more those which are 3~100m 2 / g What is 4-20 m < 2 > / g is more preferable.
When the BET specific surface area is less than 1 m 2 / g, sufficient energy density cannot be obtained. On the other hand, in the case of 200 m 2 / g or more, it has been found that the durability is lowered. The reason for this is not clear, but it is considered that, for example, an increase in the contact area with the electrolyte accompanying an increase in the BET specific surface area tends to cause an increase in leakage current and an increase in self-discharge.

本発明における難黒鉛化性炭素材料の結晶構造は、X線広角回折法で得られる(002)面の面間隔(以下、d002とする)が0.341nm以上0.390nm以下であることが好ましい。ここでいうd002は、X線としてCuKα線を用い、高純度シリコンを標準物質に使用して難黒鉛化性炭素材料の(002)面の回折ピークを測定し、そのピーク位置から算出したものである。
002が0.341nm未満になると、結晶性が向上し、難黒鉛化性炭素材料ではなくなってしまう。結晶性が向上すると、充放電時のリチウムイオンの出入りは遅くなり出力特性が落ちてしまう。また、0.390nmより大きくなると、結晶性の著しい低下に伴い、耐久性特性が落ちてしまう。従って、好ましくは0.350nm以上0.385nm以下であり、より好ましくは0.360nm以上0.380nm以下である。
The crystal structure of the non-graphitizable carbon material in the present invention is obtained by X-ray wide angle diffraction method (002) plane of the surface interval (hereinafter referred to as d 002) that is less than 0.390nm than 0.341nm preferable. D 002 here is calculated from the peak position of the (002) plane diffraction measurement of the non-graphitizable carbon material using CuKα ray as the X-ray and using high-purity silicon as the standard substance. It is.
If d 002 is less than 0.341 nm, the crystallinity is improved and the non-graphitizable carbon material is lost. When the crystallinity is improved, the entry / exit of lithium ions at the time of charging / discharging is delayed and the output characteristics are deteriorated. On the other hand, if the thickness is larger than 0.390 nm, the durability characteristics are deteriorated along with the significant decrease in crystallinity. Therefore, it is preferably 0.350 nm or more and 0.385 nm or less, and more preferably 0.360 nm or more and 0.380 nm or less.

本発明における難黒鉛化性炭素材料の細孔構造は特に制限されないが、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をVm1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をVm2(cc/g)とする時、0.001≦Vm1<0.01、かつ、0.001≦Vm2<0.01の炭素材料を満足することを特徴とする。ここでいうVm1、Vm2の算出方法は、正極活物質の項で説明した方法と同様である。   The pore structure of the non-graphitizable carbon material in the present invention is not particularly limited, but the amount of mesopores derived from pores having a diameter of 20 to 500 mm calculated by BJH method is calculated by Vm1 (cc / g) and MP method. Satisfying carbon material of 0.001 ≦ Vm1 <0.01 and 0.001 ≦ Vm2 <0.01 when the amount of micropores derived from pores having a diameter of less than 20 mm is Vm2 (cc / g) It is characterized by doing. The calculation method of Vm1 and Vm2 here is the same as the method described in the section of the positive electrode active material.

Vm1、Vm2共に0.01以上になると、細孔の増大に伴い、出力特性は向上するが、活物質層の密度を大きく上げることができなくなり、体積当たりの容量の低下を招くことや、電解液との接触面積の向上に伴い、リーク電流の増加を招くことで耐久性の低下を引く起こしやすくなる。従って、好ましくはVm1<0.0095、かつ、Vm2<0.0070であり、より好ましくはVm1<0.0085、かつ、Vm2<0.0050である。   When both Vm1 and Vm2 are 0.01 or more, the output characteristics improve as the pores increase, but the density of the active material layer cannot be increased greatly, leading to a decrease in capacity per volume, As the contact area with the liquid is improved, an increase in leakage current is likely to cause a decrease in durability. Therefore, preferably Vm1 <0.0095 and Vm2 <0.0070, more preferably Vm1 <0.0085 and Vm2 <0.0050.

本発明における難黒鉛化性炭素材料の平均粒径は、5〜30μmであることが好ましい。ここで言う平均粒径とは、粒度分布測定装置を用いて粒度分布を測定した際、全体積を100%として累積カーブを求めたとき、その累積カーブが50%となる点の粒子径を50%径とし、その50%径(Median径)のことを指すものである。
平均粒径が5μm未満であると、活物質層の密度が低下してしまい、体積当たりの容量が低下し好ましくない。更には、平均粒径が小さいことは耐久性が落ちるといった欠点も持つ。逆に、平均粒径が30μmより大きくなると、高速充放電には適さなくなる。従って、好ましくは6〜25μmであり、より好ましくは、7〜20μmである。
尚、本発明における負極活物質は、上記難黒鉛化性炭素材料を中心炭素材として他の材料を被覆したものや、上記難黒鉛化性炭素材料に他の材料を混合したものも含む。例えば、上記難黒鉛化性炭素材料の表面を他の炭素質材料で被覆した複層(コア−シェル)構造(複合物)や、上記難黒鉛化性炭素材料と黒他の炭素質材料を組み合わせたもの(混合物)が挙げられる。
The average particle size of the non-graphitizable carbon material in the present invention is preferably 5 to 30 μm. The average particle size referred to here is the particle size at which the cumulative curve becomes 50% when the cumulative curve is determined with the total volume being 100% when the particle size distribution is measured using a particle size distribution measuring device. % Diameter, and refers to the 50% diameter (Median diameter).
When the average particle size is less than 5 μm, the density of the active material layer is lowered, and the capacity per volume is lowered, which is not preferable. Furthermore, having a small average particle size has the disadvantage that durability is reduced. On the contrary, if the average particle size is larger than 30 μm, it is not suitable for high-speed charge / discharge. Accordingly, the thickness is preferably 6 to 25 μm, and more preferably 7 to 20 μm.
In addition, the negative electrode active material in the present invention includes those obtained by coating the non-graphitizable carbon material as a central carbon material with other materials, and those obtained by mixing other materials with the non-graphitizable carbon material. For example, a multilayer (core-shell) structure (composite) in which the surface of the non-graphitizable carbon material is coated with another carbonaceous material, or a combination of the non-graphitizable carbon material and black other carbonaceous material. (Mixture).

他の炭素質物とは、黒鉛、易黒鉛化性炭素材料、活性炭の表面に炭素質材料を被着された複合多孔性材料、ポリアセン系物質などのアモルファス炭素質材料、ケッチェンブラックやアセチレンブラックといったカーボンブラック、カーボンナノチューブ、フラーレン、カーボンナノフォーン、繊維状炭素質材料などであって、例えば、上記難黒鉛化性炭素材料において好ましい物性として規定されている範囲外にある炭素質材料を挙げることができる。
また、本発明における負極活物質は、上記難黒鉛化性炭素材料と、リチウムチタン複合酸化物、導電性高分子など、公知のリチウムイオン二次電池用負極材料との複合物又は混合物であってもよい。
以上のような複合物又は混合物とする場合、難黒鉛化性炭素材料の全負極活物質に対する比率は、50重量%以上とする。
Other carbonaceous materials include graphite, graphitizable carbon materials, composite porous materials with carbonaceous materials deposited on the surface of activated carbon, amorphous carbonaceous materials such as polyacenic materials, ketjen black and acetylene black Carbon black, carbon nanotube, fullerene, carbon nanophone, fibrous carbonaceous material, etc., for example, mention may be made of a carbonaceous material that is outside the range specified as a preferred physical property in the non-graphitizable carbon material. it can.
The negative electrode active material in the present invention is a composite or mixture of the non-graphitizable carbon material and a known negative electrode material for a lithium ion secondary battery such as a lithium titanium composite oxide or a conductive polymer. Also good.
In the case of the composite or mixture as described above, the ratio of the non-graphitizable carbon material to the total negative electrode active material is 50% by weight or more.

次に、本発明の非水系リチウム型蓄電素子について説明する。
集電体の材質は、蓄電素子にした際、溶出や反応などの劣化が起こらない金属箔であれば特に制限はなく、例えば、銅箔、アルミニウム箔などが挙げられる。本発明の蓄電素子においては、正極集電体をアルミニウム箔、負極集電体を銅箔とすることが好ましい。
また、集電体は貫通孔を持たない通常の金属箔でもよいし、貫通孔を有する金属箔でも構わない。集電体の厚みは、特に制限はないが、1μmより小さいと電極体の形状や強度を十分に保持できなくなり、100μmより大きいと蓄電素子として重量及び体積が大きくなりすぎ、重量及び体積当たりの性能が劣ってしまうため、1〜100μmが好ましい。
Next, the non-aqueous lithium storage element of the present invention will be described.
The material of the current collector is not particularly limited as long as it is a metal foil that does not deteriorate due to elution or reaction when it is used as a power storage element, and examples thereof include copper foil and aluminum foil. In the electricity storage device of the present invention, the positive electrode current collector is preferably an aluminum foil and the negative electrode current collector is preferably a copper foil.
Further, the current collector may be a normal metal foil having no through hole or a metal foil having a through hole. The thickness of the current collector is not particularly limited, but if it is smaller than 1 μm, the shape and strength of the electrode body cannot be sufficiently maintained, and if it is larger than 100 μm, the weight and volume of the electricity storage device become too large. Since performance will be inferior, 1-100 micrometers is preferable.

活物質層には、公知のリチウムイオン電池、キャパシタ等で活物質層に含まれる公知の成分を用いることができる。活物質層には、前述した正極活物質及び負極活物質以外に、公知の成分、例えば、バインダー、導電フィラー、増粘剤を含ませることができ、その種類には特に制限はない。   As the active material layer, a known component contained in the active material layer of a known lithium ion battery, a capacitor, or the like can be used. In addition to the positive electrode active material and the negative electrode active material described above, the active material layer can contain known components, for example, a binder, a conductive filler, and a thickener, and the type thereof is not particularly limited.

以下、非水系リチウム型蓄電素子における活物質層の成分について、その詳細を述べる。
活物質層には、必要に応じ導電性フィラーを添加してもよく、例えばカーボンブラックなどが挙げられる。その添加量は、活物質100質量%に対して0〜30質量%が好ましく、1〜20質量%がより好ましい。導電性フィラーは、高出力密度の観点からは、混合したほうが好ましいが、30質量%より多いと、電極層に占める活物質量の割合が下がり、体積当たりの出力密度が低下するので好ましくない。
上記の活物質、更に必要に応じて添加された導電性フィラーを、活物質層として集電体上に固着させるために、バインダーとして、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)、フッ素ゴム、スチレンブタジエン共重合体、セルロース誘導体などを用いることができ、その添加量は活物質100質量%に対して3〜20質量%の範囲が好ましく、5〜15質量%の範囲がより好ましい。バインダーの添加量が20質量%よりも多いと、活物質の表面をバインダーが覆ってしまい、イオンの出入りが遅くなり高出力密度が得られなくなるため好ましくない。また、バインダーの添加量が3質量%未満であると、活物質層を集電体上に固着することが難しい。
尚、本発明における電極体は、活物質層を集電体の上面(片面)のみに形成したものでもよいし、上下面(両面)に形成したものでも構わない。
Hereinafter, the details of the components of the active material layer in the non-aqueous lithium storage element will be described.
If necessary, a conductive filler may be added to the active material layer, and examples thereof include carbon black. 0-30 mass% is preferable with respect to 100 mass% of active materials, and, as for the addition amount, 1-20 mass% is more preferable. The conductive filler is preferably mixed from the viewpoint of high power density. However, if it is more than 30% by mass, the proportion of the active material in the electrode layer is lowered, and the power density per volume is lowered.
In order to fix the above-mentioned active material, and further optionally added conductive filler on the current collector as an active material layer, as a binder, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), Fluororubber, styrene butadiene copolymer, cellulose derivative and the like can be used, and the addition amount thereof is preferably in the range of 3 to 20% by mass, more preferably in the range of 5 to 15% by mass with respect to 100% by mass of the active material. . When the added amount of the binder is more than 20% by mass, the surface of the active material is covered with the binder, and ions enter and exit slowly, so that a high output density cannot be obtained. Further, when the added amount of the binder is less than 3% by mass, it is difficult to fix the active material layer on the current collector.
The electrode body in the present invention may be one in which the active material layer is formed only on the upper surface (one surface) of the current collector, or may be formed on the upper and lower surfaces (both surfaces).

活物質層を集電体に固着させた電極体において、活物質層の厚みは、通常、30〜200μm程度が好ましい。活物質層の厚みが30μm未満であると、蓄電素子全体に対する活物質量の割合が少なくなり、エネルギー密度が低下する。また、活物質層の厚み200μmより大きくなると、電極内部の抵抗が大きくなり、出力密度が低下してしまう。
電極体は、公知のリチウムイオン電池、電気二重層キャパシタ等の電極製造技術により製造することが可能であり、例えば、各種材料を水又は有機溶剤によりスラリー状にし、活物質層を集電体上に塗布して乾燥し、必要に応じてプレスすることにより得られる。また、溶剤を使用せずに、乾式で混合し、活物質をプレス成型した後、バインダーなどを用いて貼り付けることも可能である。
In the electrode body in which the active material layer is fixed to the current collector, the thickness of the active material layer is usually preferably about 30 to 200 μm. When the thickness of the active material layer is less than 30 μm, the ratio of the amount of the active material to the entire power storage element decreases, and the energy density decreases. On the other hand, when the thickness of the active material layer is larger than 200 μm, the resistance inside the electrode increases, and the output density decreases.
The electrode body can be manufactured by a known lithium ion battery, an electric double layer capacitor, or other electrode manufacturing technology. For example, various materials are slurried with water or an organic solvent, and the active material layer is placed on the current collector. It is obtained by applying to the substrate, drying, and pressing as necessary. Further, without using a solvent, it is also possible to mix by a dry method and press-mold the active material, and then affix using a binder or the like.

成型された正極電極体及び負極電極体は、セパレータを介して積層又は捲廻積層され、金属缶又はラミネートフィルムから形成された外装体内に挿入される。セパレータはリチウムイオン二次電池に用いられるポリエチレン製の微多孔膜若しくはポリプロピレン製の微多孔膜又は電気二重層コンデンサで用いられるセルロース製の不織紙などを用いることができる。
セパレータの厚みは10μm以上50μm以下が好ましい。10μm未満の厚みでは、内部のマイクロショートによる自己放電が大きくなるため好ましくない。また、50μmより厚いと、蓄電素子のエネルギー密度が減少するだけでなく、出力特性も低下するため好ましくない。
The formed positive electrode body and negative electrode body are laminated or wound around via a separator, and inserted into an outer package formed from a metal can or a laminated film. As the separator, a polyethylene microporous film or a polypropylene microporous film used in a lithium ion secondary battery, or a cellulose non-woven paper used in an electric double layer capacitor can be used.
The thickness of the separator is preferably 10 μm or more and 50 μm or less. A thickness of less than 10 μm is not preferable because self-discharge due to an internal micro-short increases. On the other hand, when the thickness is larger than 50 μm, not only the energy density of the electricity storage device is reduced but also the output characteristics are deteriorated, which is not preferable.

外装体に使用される金属缶としては、アルミニウム製のものが好ましい。また、外装体に使用されるラミネートフィルムは、金属箔と樹脂フィルムを積層したフィルムが好ましく、外層樹脂フィルム/金属箔/内装樹脂フィルムからなる3層構成のものが例示される。外層樹脂フィルムは接触等により金属箔が損傷を受けることを防止するためのものであり、ナイロンやポリエステル等の樹脂が好適に使用できる。金属箔は水分やガスの透過を防ぐためのものであり、銅、アルミニウム、ステンレス等の箔が好適に使用できる。また、内装樹脂フィルムは、内部に収納する電解液から金属箔を保護するとともに、ヒートシール時に溶融封口させるためのものであり、ポリオレフィン、酸変成ポリオレフィンが好適に使用できる。   As a metal can used for an exterior body, the thing made from aluminum is preferable. Moreover, the laminate film used for the exterior body is preferably a film in which a metal foil and a resin film are laminated, and an example of a three-layer structure comprising an outer layer resin film / metal foil / interior resin film is exemplified. The outer layer resin film is for preventing the metal foil from being damaged by contact or the like, and a resin such as nylon or polyester can be suitably used. The metal foil is for preventing the permeation of moisture and gas, and foils of copper, aluminum, stainless steel, etc. can be suitably used. The interior resin film protects the metal foil from the electrolyte contained therein and melts and seals it during heat sealing, and polyolefins and acid-modified polyolefins can be suitably used.

本発明の蓄電素子に用いられる非水系電解液の溶媒としては、炭酸エチレン(EC)、炭酸プロピレン(PC)に代表される環状炭酸エステル、炭酸ジエチル(DEC)、炭酸ジメチル(DMC)、炭酸エチルメチル(MEC)に代表される鎖状炭酸エステル、γ−ブチロラクトン(γBL)などのラクトン類、又はこれらの混合溶媒を用いることができる。
これら溶媒に溶解する電解質はリチウム塩である必要があり、好ましいリチウム塩を例示すれば、LiBF、LiPF、LiN(SO、LiN(SOCF)(SO)、LiN(SOCF)(SOH)又はこれらの混合塩を挙げることができる。
非水系電解液中の電解質濃度は、0.5〜2.0mol/Lの範囲が好ましい。0.5mol/L未満では陰イオンが不足して蓄電素子の容量が低下する。また、2.0mol/Lを超えると未溶解の塩が該電解液中に析出したり、該電解液の粘度が高くなりすぎたりすることによって、逆に伝導度が低下して出力特性が低下する。
Examples of the solvent for the non-aqueous electrolyte used in the electricity storage device of the present invention include cyclic carbonates represented by ethylene carbonate (EC) and propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl carbonate. A chain carbonate represented by methyl (MEC), a lactone such as γ-butyrolactone (γBL), or a mixed solvent thereof can be used.
The electrolyte that dissolves in these solvents must be a lithium salt. For example, LiBF 4 , LiPF 6 , LiN (SO 2 C 2 F 5 ) 2 , LiN (SO 2 CF 3 ) (SO 2 ) C 2 F 5 ), LiN (SO 2 CF 3 ) (SO 2 C 2 F 4 H), or a mixed salt thereof can be given.
The electrolyte concentration in the non-aqueous electrolyte is preferably in the range of 0.5 to 2.0 mol / L. If it is less than 0.5 mol / L, anions are insufficient and the capacity of the electricity storage device is reduced. On the other hand, if it exceeds 2.0 mol / L, undissolved salt precipitates in the electrolyte solution, or the viscosity of the electrolyte solution becomes too high, which conversely decreases the conductivity and decreases the output characteristics. To do.

負極電極体には、リチウムイオンを予めドープしておくことができる。ドープする方法としては、公知の方法、例えば、負極集電体の負極活物質層にリチウム金属箔を積層した状態で電極体を組み立てて非水系電解液に入れる方法を使用することができる。リチウムイオンを予めドープしておくことにより、蓄電素子の容量および作動電圧を制御することが可能である。   The negative electrode body can be pre-doped with lithium ions. As a method for doping, a known method, for example, a method of assembling an electrode body in a state where a lithium metal foil is laminated on a negative electrode active material layer of a negative electrode current collector and putting it in a non-aqueous electrolyte can be used. By preliminarily doping with lithium ions, it is possible to control the capacity and operating voltage of the power storage element.

以下に、本発明を実施例及び比較例によって具体的に説明するが、本発明はこれらに限定されるものではない。
<実施例1>
[正極電極体の作製]
破砕されたヤシ殻炭化物を、小型炭化炉において窒素中、500℃で3時間炭化処理した。処理後の該炭化物を賦活炉内へ入れ、1kg/hの水蒸気を予熱炉で加温した状態で該賦活炉内へ投入し、900℃まで8時間かけて昇温した後に取り出し、窒素雰囲気下で冷却して活性炭を得た。得られた活性炭を10時間通水洗浄を行った後に水切りした。その後、115℃に保持された電気乾燥機内で10時間乾燥した後に、ボールミルで1時間粉砕を行い、正極材料となる活性炭1を得た。
本活性炭1を、ユアサアイオニクス社製細孔分布測定装置(AUTOSORB−1 AS−1−MP)で、細孔分布を測定した。その結果、BET比表面積は2,360m/g、メソ孔量(V1)は0.52cc/g、マイクロ孔量(V2)は0.88cc/gであった。この活性炭1を正極活物質に用い、該活性炭1 80.8重量部、ケッチェンブラック6.20重量部、PVDF(ポリフッ化ビニリデン)10.0重量部およびPVP(ポリビニルピロリドン)3.00重量部とNMP(N−メチルピロリドン)を混合して、スラリーを得た。次いで、得られたスラリーを厚さ15μmのアルミニウム箔の片面に塗布し、乾燥し、プレスして、活物質層の厚さが55μmの正極電極体を得た。
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
<Example 1>
[Preparation of positive electrode body]
The crushed palm shell carbide was carbonized in nitrogen in a small carbonization furnace at 500 ° C. for 3 hours. The treated carbide is placed in an activation furnace, 1 kg / h of steam is heated in a preheating furnace, and the temperature is raised to 900 ° C. over 8 hours. To obtain activated carbon. The obtained activated carbon was washed with water for 10 hours and then drained. Then, after drying for 10 hours in an electric dryer maintained at 115 ° C., pulverization was performed for 1 hour by a ball mill to obtain activated carbon 1 as a positive electrode material.
The pore distribution of this activated carbon 1 was measured with a pore distribution measuring device (AUTOSORB-1 AS-1-MP) manufactured by Yuasa Ionics. As a result, the BET specific surface area was 2,360 m 2 / g, the mesopore volume (V1) was 0.52 cc / g, and the micropore volume (V2) was 0.88 cc / g. Using this activated carbon 1 as a positive electrode active material, the activated carbon 1 80.8 parts by weight, Ketjen black 6.20 parts by weight, PVDF (polyvinylidene fluoride) 10.0 parts by weight and PVP (polyvinylpyrrolidone) 3.00 parts by weight And NMP (N-methylpyrrolidone) were mixed to obtain a slurry. Next, the obtained slurry was applied to one side of an aluminum foil having a thickness of 15 μm, dried, and pressed to obtain a positive electrode body having an active material layer thickness of 55 μm.

[負極電極体の作製]
負極活物質として、難黒鉛化性炭素材料1(カーボトロンP:呉羽化学工業(株)製)を用いることとし、この難黒鉛化性炭素材料の物性評価を行った。ユアサアイオニクス社製細孔分布測定装置(AUTOSORB−1 AS−1−MP)を用いて解析した結果、BET比表面積は5.2m/g、細孔分布はメソ孔量(Vm1)が0.0085cc/g、マイクロ孔量(Vm2)が0.0017cc/gであった。また、X線広角回折測定をX線としてCuKα線を用いて行い、高純度Siを内標に使用して(002)面の回折ピークを測定した結果、d002は0.372であった。さらに、島津製作所社製レーザー回折式粒度分布測定装置(SALD−2000J)を用いて平均粒径を測定した結果、11μmであった。
上記難黒鉛化性炭素材料1 83.4重量部、アセチレンブラック8.3重量部、及びPVDF(ポリフッ化ビニリデン)8.3重量部とNMP(N−メチルピロリドン)を混合して、スラリーを得た。次いで、得られたスラリーを厚さ15μmの銅箔の片面に塗布し、乾燥し、プレスして、活物質層の厚さが60μmの負極電極体を得た。この電極体に、難黒鉛化性炭素材料単位重量あたり400mAh/gに相当するリチウムイオンを、リチウム金属箔を用いて電気化学的にドーピングした。
[Preparation of negative electrode body]
As the negative electrode active material, non-graphitizable carbon material 1 (Carbotron P: manufactured by Kureha Chemical Industry Co., Ltd.) was used, and physical properties of this non-graphitizable carbon material were evaluated. As a result of analysis using a pore distribution measuring device (AUTOSORB-1 AS-1-MP) manufactured by Yuasa Ionics Co., Ltd., the BET specific surface area was 5.2 m 2 / g, and the pore distribution was a mesopore amount (Vm1) of 0. .0085 cc / g, and the micropore volume (Vm2) was 0.0017 cc / g. Further, X-ray wide-angle diffraction measurement was performed using CuKα rays as X-rays, and as a result of measuring the diffraction peak on the (002) plane using high purity Si as an internal standard, d 002 was 0.372. Furthermore, it was 11 micrometers as a result of measuring an average particle diameter using the Shimadzu Corporation laser diffraction type particle size distribution measuring apparatus (SALD-2000J).
The above-mentioned non-graphitizable carbon material 1 83.4 parts by weight, acetylene black 8.3 parts by weight, PVDF (polyvinylidene fluoride) 8.3 parts by weight and NMP (N-methylpyrrolidone) are mixed to obtain a slurry. It was. Next, the obtained slurry was applied to one side of a copper foil having a thickness of 15 μm, dried and pressed to obtain a negative electrode body having an active material layer thickness of 60 μm. The electrode body was electrochemically doped with lithium ions corresponding to 400 mAh / g per unit weight of the non-graphitizable carbon material using a lithium metal foil.

[蓄電素子の組立と性能]
得られた負極電極体、及び正極電極体の間に、ポリエチレン系セパレータ(厚み30μm)を積層して、ラミネートフィルムから形成された外装体内に挿入し、電解液を注入して該外装体を密閉し、非水系リチウム型蓄電素子を組立てた。エチレンカーボネートとメチルエチルカーボネートを1:4重量比で混合した溶媒に1mol/lの濃度でLiN(SOを溶解した溶液を電解液として使用した。
組立てた蓄電素子を0.5mAの電流で4.0Vまで充電し、その後、4.0Vの定電圧を印加する定電流定電圧充電を2時間行った。続いて、0.5mAの定電流で2.5Vまで放電した。これを1サイクルとし、続けて13サイクルまで充放電を繰り返した。13サイクル目の放電容量を本蓄電素子の容量とした際、本蓄電素子の容量は、46mAh/gであった。
[Assembly and performance of storage element]
A polyethylene separator (thickness 30 μm) is laminated between the obtained negative electrode body and the positive electrode body, inserted into an outer package formed from a laminate film, and an electrolyte is injected to seal the outer package. Then, a non-aqueous lithium storage element was assembled. A solution obtained by dissolving LiN (SO 2 C 2 F 5 ) 2 at a concentration of 1 mol / l in a solvent in which ethylene carbonate and methyl ethyl carbonate were mixed at a weight ratio of 1: 4 was used as an electrolytic solution.
The assembled power storage element was charged to 4.0 V with a current of 0.5 mA, and then constant current and constant voltage charging in which a constant voltage of 4.0 V was applied was performed for 2 hours. Subsequently, the battery was discharged to 2.5 V with a constant current of 0.5 mA. This was defined as one cycle, and charging and discharging were repeated up to 13 cycles. When the discharge capacity at the thirteenth cycle was defined as the capacity of the power storage element, the capacity of the power storage element was 46 mAh / g.

また、作製した蓄電素子を1mAの電流で4.0Vまで充電し、その後4.0Vの定電圧を印加する定電流定電圧充電を2時間行った。次いで、1mAの定電流で2.5Vまで放電した。放電容量は、0.341mAhであった。次に同様の充電を行い250mAで2.5Vまで放電したところ、0.157mAhの容量が得られた。すなわち、1mAでの放電容量に対する250mAでの放電容量の比(以下「出力特性」ともいう。)は0.460であった。
さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。試験開始時(0hとする)と1000h経過後における抵抗倍率を測定した。ここでいう抵抗倍率とは、(1000h経過後の0.1Hzでの抵抗値)/(0hでの0.1Hzでの抵抗値)で表される数値とする。1000h経過後の抵抗倍率は1.19であった。
Moreover, the produced electrical storage element was charged to 4.0V with the electric current of 1 mA, and the constant current constant voltage charge which applies a constant voltage of 4.0V was performed for 2 hours after that. Next, the battery was discharged to 2.5 V with a constant current of 1 mA. The discharge capacity was 0.341 mAh. Next, when the same charge was performed and the battery was discharged at 250 mA to 2.5 V, a capacity of 0.157 mAh was obtained. That is, the ratio of the discharge capacity at 250 mA to the discharge capacity at 1 mA (hereinafter also referred to as “output characteristics”) was 0.460.
Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. The resistance magnification was measured at the start of the test (0 h) and after 1000 h had elapsed. The resistance magnification here is a numerical value represented by (resistance value at 0.1 Hz after elapse of 1000 h) / (resistance value at 0.1 Hz at 0 h). The resistance magnification after 1000 hours was 1.19.

<実施例2>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
石炭系ピッチを空気雰囲気下250℃で約2時間酸化処理を行った後、真空下1100℃で1時間熱処理を行った。得られた材料を、ボールミル粉砕機で約4時間粉砕することにより、負極材料となる難黒鉛化性炭素材料2を得た。
上記難黒鉛化性炭素材料2の物性評価を実施例1と同様な手法で行った。BET比表面積は4.1m/g、メソ孔量(Vm1)が0.0081cc/g、マイクロ孔量(Vm2)が0.0012cc/g、d002は0.375、平均粒径は15μmであった。
<Example 2>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
The coal-based pitch was oxidized at 250 ° C. for about 2 hours in an air atmosphere, and then heat-treated at 1100 ° C. for 1 hour under vacuum. The obtained material was pulverized with a ball mill pulverizer for about 4 hours to obtain a non-graphitizable carbon material 2 serving as a negative electrode material.
Evaluation of physical properties of the non-graphitizable carbon material 2 was performed in the same manner as in Example 1. BET specific surface area was 4.1 m 2 / g, mesopore Anaryou (Vm1) is 0.0081cc / g, micropore volume (Vm2) is 0.0012cc / g, d 002 is 0.375, and the average particle size in 15μm there were.

以下、実施例1と同様にて電極体を作製した。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、46mAh/gであった。また。出力特性は、0.451であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.07であった。
Thereafter, an electrode body was produced in the same manner as in Example 1.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 46 mAh / g. Also. The output characteristic was 0.451. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.07.

<実施例3>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
等方性ピッチをステンレス製皿に入れ、熱反応させた。熱反応は、窒素雰囲気下で行い、炉内が660℃になるまで昇温し、同温度で12時間保持した後、自然冷却した。得られた材料を遊星型ボールミルを用いて粉砕することで、負極材料となる難黒鉛化性炭素材料3を得た。
上記難黒鉛化性炭素材料3の物性評価を実施例1と同様な手法で行った。BET比表面積は98m/g、メソ孔量(Vm1)が0.0323cc/g、マイクロ孔量(Vm2)が0.0566cc/g、d002は0.344、平均粒径は0.9μmであった。
以下、実施例1と同様にて電極体を作製した。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、45mAh/gであった。また。出力特性は、0.466であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.25であった。
<Example 3>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
Isotropic pitch was placed in a stainless steel dish and allowed to react by heat. The thermal reaction was performed in a nitrogen atmosphere, the temperature was raised until the inside of the furnace reached 660 ° C., kept at the same temperature for 12 hours, and then naturally cooled. The obtained material was pulverized using a planetary ball mill to obtain a non-graphitizable carbon material 3 serving as a negative electrode material.
The physical properties of the non-graphitizable carbon material 3 were evaluated in the same manner as in Example 1. BET specific surface area was 98m 2 / g, mesopore Anaryou (Vm1) is 0.0323cc / g, micropore volume (Vm2) is 0.0566cc / g, d 002 is 0.344, and the average particle size in the 0.9μm there were.
Thereafter, an electrode body was produced in the same manner as in Example 1.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 45 mAh / g. Also. The output characteristic was 0.466. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.25.

<比較例1>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
フェノール樹脂硬化体をステンレス製皿に入れ、熱反応させた。熱反応は、窒素雰囲気下で行い、炉内が630℃になるまで昇温し、同温度で4時間保持した後、自然冷却した。得られた材料を遊星型ボールミルを用いて粉砕することで、負極材料となる難黒鉛化性炭素材料4を得た。
上記難黒鉛化性炭素材料4の物性評価を実施例1と同様な手法で行った。BET比表面積は390m/g、メソ孔量(Vm1)が0.0251cc/g、マイクロ孔量(Vm2)が0.121cc/g、d002は0.383、平均粒径は4.2μmであった。
以下、実施例1と同様にて電極体を作製した。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、43mAh/gであった。また。出力特性は、0.472であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.92であった。
<Comparative Example 1>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
The cured phenol resin was placed in a stainless steel dish and allowed to react by heat. The thermal reaction was performed in a nitrogen atmosphere, the temperature was raised until the inside of the furnace reached 630 ° C., kept at the same temperature for 4 hours, and then naturally cooled. The obtained material was pulverized using a planetary ball mill to obtain a non-graphitizable carbon material 4 serving as a negative electrode material.
The physical properties of the non-graphitizable carbon material 4 were evaluated in the same manner as in Example 1. BET specific surface area of 390m 2 / g, mesopore Anaryou (Vm1) is 0.0251cc / g, micropore volume (Vm2) is 0.121cc / g, d 002 is 0.383, and the average particle size in the 4.2μm there were.
Thereafter, an electrode body was produced in the same manner as in Example 1.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 43 mAh / g. Also. The output characteristic was 0.472. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.92.

<比較例2>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
石炭系ピッチを空気雰囲気下300℃で約2時間酸化処理を行った後、真空下1100℃で2時間熱処理を行った。得られた材料を、ボールミル粉砕機で約1時間粉砕することにより、負極材料となる難黒鉛化性炭素材料5を得た。
上記難黒鉛化性炭素材料5の物性評価を実施例1と同様な手法で行った。BET比表面積は0.95m/g、メソ孔量(Vm1)が0.0009cc/g、マイクロ孔量(Vm2)が0.0012cc/g、d002は0.375、平均粒径は30μmであった。
以下、実施例1と同様にて電極体を作製した。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、42mAh/gであった。また。出力特性は、0.311であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.08であった。
<Comparative example 2>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
The coal-based pitch was oxidized at 300 ° C. for about 2 hours in an air atmosphere, and then heat-treated at 1100 ° C. for 2 hours under vacuum. The obtained material was pulverized with a ball mill pulverizer for about 1 hour to obtain a non-graphitizable carbon material 5 serving as a negative electrode material.
Evaluation of physical properties of the non-graphitizable carbon material 5 was performed in the same manner as in Example 1. BET specific surface area was 0.95 m 2 / g, mesopore Anaryou (Vm1) is 0.0009cc / g, micropore volume (Vm2) is 0.0012cc / g, d 002 is 0.375, and the average particle size in 30μm there were.
Thereafter, an electrode body was produced in the same manner as in Example 1.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 42 mAh / g. Also. The output characteristic was 0.311. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.08.

<比較例3>
[正極電極体の作製]
活物質として、市販の活性炭2を用い、この活性炭2の物性評価を実施例1と同様な方法にて行った。その結果、BET比表面積は1620m/g、メソ孔量(V1)は0.18cc/g、マイクロ孔量(V2)は0.67cc/gであった。
以下、実施例1と同様にて電極体を作製した。
[負極電極体の作製]
実施例1と同様のものを用いた。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、39mAh/gであった。また。出力特性は、0.322であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.90であった。
<Comparative Example 3>
[Preparation of positive electrode body]
Commercially available activated carbon 2 was used as the active material, and physical properties of this activated carbon 2 were evaluated in the same manner as in Example 1. As a result, the BET specific surface area was 1620 m 2 / g, the mesopore volume (V1) was 0.18 cc / g, and the micropore volume (V2) was 0.67 cc / g.
Thereafter, an electrode body was produced in the same manner as in Example 1.
[Preparation of negative electrode body]
The same one as in Example 1 was used.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 39 mAh / g. Also. The output characteristic was 0.322. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.90.

<比較例4>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
市販の活性炭3(BET法による比表面積が1,955m/g)150gをステンレススチールメッシュ製の籠に入れ、石炭系ピッチ300gを入れたステンレス製バットの上に置き、電気炉 (炉内有効寸法300mm×300mm×300mm)内に設置して、熱反応を行った。熱処理は窒素雰囲気下で、670℃まで4時間で昇温し、同温度で4時間保持し、続いて自然冷却により60℃まで冷却した後、炉から取り出し、複合多孔性材料1が得られた。
得られた複合多孔性材料1の物性を、実施例1と同様な手法で行った。BET比表面積は255m/g、メソ孔量(Vm1)が0.0580cc/g、マイクロ孔量(Vm2)が0.0854cc/g、d002は0.369、平均粒径は2.9μmであった。
次いで、上記で得た複合多孔性材料1 83.4重量部、アセチレンブラック8.30重量部およびポリフッ化ビニリデン(PVdF)8.30重量部とN−メチルピロリドン(NMP)を混合してスラリーを得た。次いで、得られたスラリーを厚さ15μmの銅箔の片面に塗布し、乾燥し、プレスして、活物質層の厚さが60μmの負極電極体を得た。この電極体に、複合多孔性材料重量あたり760mAh/gに相当するリチウムイオンを、リチウム金属箔を用いて電気化学的にドーピングした。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、42mAh/gであった。また。出力特性は、0.491であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.70であった。
<Comparative Example 4>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
150 g of commercially available activated carbon 3 (specific surface area by BET method is 1,955 m 2 / g) is placed in a stainless steel mesh jar and placed on a stainless steel bat containing 300 g of coal-based pitch. It installed in the dimension 300mmx300mmx300mm), and the thermal reaction was performed. In the heat treatment, the temperature was raised to 670 ° C. in 4 hours in a nitrogen atmosphere, held at the same temperature for 4 hours, then cooled to 60 ° C. by natural cooling, and then taken out from the furnace to obtain composite porous material 1 .
The physical properties of the obtained composite porous material 1 were measured in the same manner as in Example 1. BET specific surface area of 255m 2 / g, mesopore Anaryou (Vm1) is 0.0580cc / g, micropore volume (Vm2) is 0.0854cc / g, d 002 is 0.369, and the average particle size in the 2.9μm there were.
Next, 83.4 parts by weight of the composite porous material 1 obtained above, 8.30 parts by weight of acetylene black, 8.30 parts by weight of polyvinylidene fluoride (PVdF), and N-methylpyrrolidone (NMP) were mixed to prepare a slurry. Obtained. Next, the obtained slurry was applied to one side of a copper foil having a thickness of 15 μm, dried and pressed to obtain a negative electrode body having an active material layer thickness of 60 μm. The electrode body was electrochemically doped with lithium ions corresponding to 760 mAh / g per weight of the composite porous material using a lithium metal foil.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 42 mAh / g. Also. The output characteristic was 0.491. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.70.

<比較例5>
[正極電極体の作製]
比較例3と同様のものを用いた。
[負極電極体の作製]
比較例4と同様のものを用いた。
[蓄電素子の組立と性能]
以下、実施例1と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、41mAh/gであった。また。出力特性は、0.354であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は2.02であった。
<Comparative Example 5>
[Preparation of positive electrode body]
The same one as in Comparative Example 3 was used.
[Preparation of negative electrode body]
The same one as in Comparative Example 4 was used.
[Assembly and performance of storage element]
Hereinafter, in the same manner as in Example 1, a non-aqueous lithium storage element was assembled and evaluated. The capacity of this power storage element was 41 mAh / g. Also. The output characteristic was 0.354. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 2.02.

Figure 0005554932
Figure 0005554932

<実施例4>
[正極電極体の作製]
実施例1と同様のものを用いた。
[負極電極体の作製]
実施例1と同様のものを用いた。
[蓄電素子の組立と性能]
得られた負極電極体、及び正極電極体の間に、ポリエチレン系セパレータ(厚み30μm)を積層して、ラミネートフィルムから形成された外装体内に挿入し、電解液を注入して該外装体を密閉し、非水系リチウム型蓄電素子を組立てた。エチレンカーボネートとメチルエチルカーボネートを1:4重量比で混合した溶媒に1mol/lの濃度でLiPFを溶解した溶液を、電解液として使用した。
以下、実施例1と同様に蓄電素子の組立と性能評価を行った。本蓄電素子の容量は、47mAh/gであった。また。出力特性は、0.594であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.30であった。
<Example 4>
[Preparation of positive electrode body]
The same one as in Example 1 was used.
[Preparation of negative electrode body]
The same one as in Example 1 was used.
[Assembly and performance of storage element]
A polyethylene separator (thickness 30 μm) is laminated between the obtained negative electrode body and the positive electrode body, inserted into an outer package formed from a laminate film, and an electrolyte is injected to seal the outer package. Then, a non-aqueous lithium storage element was assembled. A solution obtained by dissolving LiPF 6 at a concentration of 1 mol / l in a solvent in which ethylene carbonate and methyl ethyl carbonate were mixed at a weight ratio of 1: 4 was used as an electrolytic solution.
Hereinafter, as in Example 1, the assembly and performance evaluation of the electricity storage element were performed. The capacity of this power storage element was 47 mAh / g. Also. The output characteristic was 0.594. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.30.

<実施例5>
[正極電極体の作製]
実施例2と同様のものを用いた。
[負極電極体の作製]
実施例2と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、47mAh/gであった。また。出力特性は、0.581であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.17であった。
<Example 5>
[Preparation of positive electrode body]
The same one as in Example 2 was used.
[Preparation of negative electrode body]
The same one as in Example 2 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 47 mAh / g. Also. The output characteristic was 0.581. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.17.

<実施例6>
[正極電極体の作製]
実施例3と同様のものを用いた。
[負極電極体の作製]
実施例3と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、46mAh/gであった。また。出力特性は、0.595であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.35であった。
<Example 6>
[Preparation of positive electrode body]
The same one as in Example 3 was used.
[Preparation of negative electrode body]
The same one as in Example 3 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 46 mAh / g. Also. The output characteristic was 0.595. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.35.

<比較例6>
[正極電極体の作製]
比較例1と同様のものを用いた。
[負極電極体の作製]
比較例1と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、44mAh/gであった。また。出力特性は、0.605であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.95であった。
<Comparative Example 6>
[Preparation of positive electrode body]
The thing similar to the comparative example 1 was used.
[Preparation of negative electrode body]
The thing similar to the comparative example 1 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 44 mAh / g. Also. The output characteristic was 0.605. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.95.

<比較例7>
[正極電極体の作製]
比較例2と同様のものを用いた。
[負極電極体の作製]
比較例2と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、42mAh/gであった。また。出力特性は、0.384であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は1.19であった。
<Comparative Example 7>
[Preparation of positive electrode body]
The thing similar to the comparative example 2 was used.
[Preparation of negative electrode body]
The thing similar to the comparative example 2 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 42 mAh / g. Also. The output characteristic was 0.384. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 1.19.

<比較例8>
[正極電極体の作製]
比較例3と同様のものを用いた。
[負極電極体の作製]
比較例3と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、39mAh/gであった。また。出力特性は、0.352であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は2.47であった。
<Comparative Example 8>
[Preparation of positive electrode body]
The same one as in Comparative Example 3 was used.
[Preparation of negative electrode body]
The same one as in Comparative Example 3 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 39 mAh / g. Also. The output characteristic was 0.352. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 2.47.

<比較例9>
[正極電極体の作製]
比較例4と同様のものを用いた。
[負極電極体の作製]
比較例4と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、45mAh/gであった。また。出力特性は、0.636であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は2.33であった。
<Comparative Example 9>
[Preparation of positive electrode body]
The same one as in Comparative Example 4 was used.
[Preparation of negative electrode body]
The same one as in Comparative Example 4 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 45 mAh / g. Also. The output characteristic was 0.636. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 2.33.

<比較例10>
[正極電極体の作製]
比較例5と同様のものを用いた。
[負極電極体の作製]
比較例5と同様のものを用いた。
[蓄電素子の組立と性能]
実施例4と同様に非水系リチウム型蓄電素子を組立てて評価を行った。本蓄電素子の容量は、42mAh/gであった。また。出力特性は、0.401であった。さらに、組立てた蓄電素子の耐久性試験を60℃、3.8V印加の条件で行った。1000h経過後、抵抗倍率は3.02であった。
<Comparative Example 10>
[Preparation of positive electrode body]
The thing similar to the comparative example 5 was used.
[Preparation of negative electrode body]
The thing similar to the comparative example 5 was used.
[Assembly and performance of storage element]
A non-aqueous lithium storage element was assembled and evaluated in the same manner as in Example 4. The capacity of this power storage element was 42 mAh / g. Also. The output characteristic was 0.401. Furthermore, the durability test of the assembled electrical storage element was performed under the conditions of 60 ° C. and 3.8 V application. After 1000 hours, the resistance magnification was 3.02.

Figure 0005554932
Figure 0005554932

以上より、本願発明に係る蓄電素子は、高エネルギー密度及び高出力密度に加え、高耐久性を兼ね揃えた特性であることが分かる。   As mentioned above, it turns out that the electrical storage element which concerns on this invention is the characteristic which combined high durability in addition to high energy density and high output density.

本発明の蓄電素子は、自動車において、内燃機関または燃料電池、モーター、及び蓄電素子を組み合わせたハイブリット駆動システムの分野、さらには瞬間電力ピークのアシスト用途などで好適に利用できる。   The power storage device of the present invention can be suitably used in automobiles, in the field of a hybrid drive system that combines an internal combustion engine or a fuel cell, a motor, and a power storage device, and for assisting instantaneous power peaks.

Claims (6)

負極集電体に負極活物質層を設けた負極電極体、正極集電体に正極活物質層を設けた正極電極体、及びセパレータを積層してなる電極積層体、並びにリチウムイオンを含有した電解質を含む非水系電解液を外装体に収納してなる非水系リチウム型蓄電素子であって、該正極活物質が活性炭を主成分とし含み、ここで、該活性炭は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をV1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をV2(cc/g)とする時、0.3<V1≦0.8、かつ、0.5≦V2≦1.0を満足し、BET法により測定される比表面積が1,500m/g以上3,000m/g以下であり、そして該負極活物質が、BET法により測定される比表面積が1m/g以上200m/g未満である難黒鉛化性炭素材料を主成分として含み、該電解質が、LiPF 及びLiN(SO からなる群から選ばれる少なくとも1種であり、そして該非水系電解液の溶媒は、1つの環状炭酸エステルと1つの鎖状炭酸エステルとの混合溶媒であることを特徴とする非水系リチウム型蓄電素子。 A negative electrode body in which a negative electrode active material layer is provided on a negative electrode current collector, a positive electrode body in which a positive electrode current collector is provided with a positive electrode active material layer, an electrode laminate formed by laminating a separator, and an electrolyte containing lithium ions A non-aqueous lithium-type energy storage device in which a non-aqueous electrolyte solution containing a non-aqueous electrolyte solution is housed in an exterior body, wherein the positive electrode active material contains activated carbon as a main component, where the activated carbon has a diameter of 20 mm calculated by the BJH method. When the amount of mesopores derived from pores having a diameter of 500 mm or less is V1 (cc / g) and the amount of micropores derived from pores having a diameter of less than 20 mm calculated by the MP method is V2 (cc / g). 3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 are satisfied, the specific surface area measured by the BET method is 1,500 m 2 / g to 3,000 m 2 / g, and The negative electrode active material was measured by the BET method. Specific surface area viewed contains a non-graphitizable carbon material is less than 1 m 2 / g or more 200 meters 2 / g as principal components, the electrolyte is from the group consisting of LiPF 6 and LiN (SO 2 C 2 F 5 ) 2 A non-aqueous lithium storage element , which is at least one selected, and the solvent of the non-aqueous electrolyte is a mixed solvent of one cyclic carbonate and one chain carbonate . 前記V1が0.52であり、かつ、前記V2が0.88である、請求項1に記載の非水系リチウム型蓄電素子。The non-aqueous lithium storage element according to claim 1, wherein the V1 is 0.52 and the V2 is 0.88. X線広角回折法で得られる前記難黒鉛化性炭素材料の(002)面の面間隔が0.341nm以上0.390nm以下である、請求項1又は2に記載の非水系リチウム型蓄電素子。 Spacing of (002) plane of the flame-graphitizable carbon material obtained by wide-angle X-ray diffraction method is less than 0.390nm than 0.341Nm, nonaqueous lithium-type storage element according to claim 1 or 2. 前記難黒鉛化性炭素材料は、BJH法により算出した直径20Å以上500Å以下の細孔に由来するメソ孔量をVm1(cc/g)、MP法により算出した直径20Å未満の細孔に由来するマイクロ孔量をVm2(cc/g)とする時、0.001≦Vm1<0.01、かつ、0.001≦Vm2<0.01を満足する炭素材料である、請求項1〜3のいずれか1項に記載の非水系リチウム型蓄電素子。 The non-graphitizable carbon material is derived from Vm1 (cc / g) mesopore volume derived from pores having a diameter of 20 to 500 mm calculated by the BJH method and pores having a diameter of less than 20 mm calculated by the MP method. when the micro pore volume and Vm2 (cc / g), 0.001 ≦ Vm1 <0.01 and a carbon material satisfying 0.001 ≦ Vm2 <0.01, one of the claim 1-3 nonaqueous lithium-type storage element according to any one of claims. 前記難黒鉛化性炭素材料の平均粒径が5〜30μmである、請求項1〜のいずれか1項に記載の非水系リチウム型蓄電素子。 The average particle diameter of the flame-graphitizable carbon material is 5 to 30 [mu] m, a non-aqueous lithium-type storage element according to any one of claims 1-4. 前記混合溶媒が、エチレンカーボネートとメチルエチルカーボネートを1:4重量比で混合した溶媒である、請求項1〜5のいずれか1項に記載の非水系リチウム型蓄電素子。 The non-aqueous lithium storage element according to any one of claims 1 to 5, wherein the mixed solvent is a solvent obtained by mixing ethylene carbonate and methyl ethyl carbonate at a weight ratio of 1: 4.
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