JP3236400B2 - Non-aqueous secondary battery - Google Patents
Non-aqueous secondary batteryInfo
- Publication number
- JP3236400B2 JP3236400B2 JP08065093A JP8065093A JP3236400B2 JP 3236400 B2 JP3236400 B2 JP 3236400B2 JP 08065093 A JP08065093 A JP 08065093A JP 8065093 A JP8065093 A JP 8065093A JP 3236400 B2 JP3236400 B2 JP 3236400B2
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- particles
- secondary battery
- carbon
- battery
- 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.)
- Expired - Lifetime
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
Description
【０００１】[0001]
【産業上の利用分野】本発明は炭素質材料粒子から主と
して構成される負極と充放電可能な正極と有機溶媒系電
解液からなる非水二次電池に関し、特に、主として黒鉛
質粒子および擬黒鉛構造を有する炭素質粒子からなる複
合負極を具備してなる二次電池に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonaqueous secondary battery comprising a negative electrode mainly composed of carbonaceous material particles, a chargeable / dischargeable positive electrode, and an organic solvent-based electrolyte. The present invention relates to a secondary battery including a composite negative electrode composed of carbonaceous particles having a structure.
【０００２】[0002]
【従来の技術】近年、携帯用電子機器の小型化に伴い、
その電源として、軽量・小型かつ高容量な二次電池が要
望されている。有機溶媒を電解液とした非水二次電池の
負極として金属リチウムを用いると高容量になることが
知られている。しかしながら、金属リチウム負極では、
充放電の繰り返しに伴って生成する樹枝状のリチウム
（リチウムデンドライト）による内部短絡や電流効率の
低下などが、高容量かつ長寿命な電池の実用化の大きな
障害となっている。また、金属リチウムを用いる電池で
は、短絡時の発熱などで電池が高温状態になると、金属
リチウムの高い反応性のため、発火や電池缶の破裂の危
険を含んでおり、安全性の点でも大きな問題を残してい
る。2. Description of the Related Art In recent years, as portable electronic devices have become smaller,
As the power source, a lightweight, small and high capacity secondary battery is demanded. It is known that when metal lithium is used as a negative electrode of a non-aqueous secondary battery using an organic solvent as an electrolyte, the capacity becomes high. However, with a metal lithium anode,
Internal short-circuit and reduction in current efficiency due to dendritic lithium (lithium dendrite) generated by repeated charge / discharge have been major obstacles to the practical use of high-capacity and long-life batteries. Also, in the case of batteries using metallic lithium, if the battery becomes hot due to heat generation during a short circuit, etc., there is a danger of ignition and rupture of the battery can due to the high reactivity of metallic lithium. The problem remains.
【０００３】このような欠点の改善を目的に、有機溶媒
を電解液とした非水二次電池に用いられる負極として、
電気化学的にリチウムイオンを吸蔵・放出可能な炭素質
材料が注目されている。このような負極に用いられる炭
素質材料として、活性炭のように非晶質を多く含むもの
からグラファイトに代表されるように結晶の発達したも
のに到るまで、種々の材料が検討されている。In order to improve such disadvantages, as a negative electrode used in a non-aqueous secondary battery using an organic solvent as an electrolyte,
Attention has been focused on carbonaceous materials capable of electrochemically storing and releasing lithium ions. As the carbonaceous material used for such a negative electrode, various materials have been studied, from a material containing a large amount of amorphous material such as activated carbon to a material having a developed crystal as represented by graphite.
【０００４】非晶質を多く含む炭素質材料は、通常、き
わめて表面積（ＳA ＞１００ｍ2/ｇ）が大きく炭素網面
の間隔も広く（ｄ002 ＞０．３３７ｎｍ）、結晶化の進
んでいないものである。このタイプのものは表面吸着量
が多いために炭素原子当りのリチウム吸蔵量は大きいが
電流効率が低く、サイクル性も低い。炭素網面がある程
度成長しているが完全には黒鉛化していない、いわゆ
る、擬黒鉛構造を有する炭素質材料は、従来より金属リ
>チウム負極やリチウム合金負極で使用される電解液を
用いてリチウムを吸蔵・放出可能である。A carbonaceous material containing a large amount of amorphous material usually has an extremely large surface area (S A > 100 m 2 / g) and a large spacing between carbon network planes (d 002 > 0.337 nm). Not something. This type has a large amount of lithium adsorbed per carbon atom due to a large amount of surface adsorption, but has low current efficiency and low cyclability. Carbonaceous materials having a so-called pseudo-graphite structure, in which the carbon mesh surface has grown to some extent but has not been completely graphitized, have conventionally been made of metal refining.
> Lithium can be inserted / extracted using the electrolyte used for the negative electrode of lithium or lithium alloy.
【０００５】一方、グラファイトは、炭素網面の間隔が
狭く（ｄ002 ＜０．３３７ｎｍ）、炭素網面方向及び網
面の積層方向に結晶子の成長したものであり、その粒子
の形状は異方性の発達したものである。このような炭素
材料は陽イオン、陰イオンどちらもその炭素網面間にイ
ンターカレーションし、層間化合物を形成することが知
られており、導電材料、有機合成反応触媒や電池として
の応用も考えられている。このようなグラファイトを電
池の負極として用いることは特開昭５７−２０８０７９
号公報、特開昭５８−１９２２６６号公報、特開昭５９
−１４３２８０号公報、特開昭６０−５４１８１号公
報、特開昭６０−１８２６７０号公報、特開昭６０−２
２１９７３号公報、特開昭６１−７５６７号公報、特開
平１−３１１５６５号公報、特開平４−１７１６７７号
公報などに提案されている。[0005] On the other hand, graphite has a narrow carbon network plane (d 002 <0.337 nm), and crystallites grow in the carbon network plane direction and the lamination direction of the network plane. It is an anisotropic one. It is known that such a carbon material intercalates both cations and anions between its carbon network planes to form an intercalation compound, and is also considered to be applied to conductive materials, organic synthesis reaction catalysts, and batteries. Have been. The use of such graphite as a negative electrode of a battery is disclosed in Japanese Patent Application Laid-Open No. 57-208079.
JP, JP-A-58-192266, JP-A-59-192266
-143280, JP-A-60-54181, JP-A-60-182670, JP-A-60-2
Japanese Patent Application Laid-Open Nos. 211973, 61-7567, 1-311565, 4-171677, and the like.
【０００６】これらの特許には使用できる有機溶媒とし
てプロピレンカーボネート（以下ＰＣと略記する。）、
テトラヒドロフラン（以下ＴＨＦと略記する。）、γ−
ブチロラクトン（以下γ−ＢＬと略記する。）、１，２
−ジメトキシエタン（以下ＤＭＥと略記する。）、スル
ホラン、エチレンカーボネート（以下ＥＣと略記す
る。）などが記載されている。実施例としてはＬｉＣｌ
Ｏ4 あるいはＬｉＢＦ4 を用い、代表的溶媒としてＰＣ
あるいはＴＨＦを用いている。ＰＣを溶媒とする電解液
では、Ｊ．Ｅｌｅｃｔｒｏｃｈｅｍ．Ｓｏｃ．，１１７
Ｐ．２２２（１９７０）に記載のごとく、グラファイ
トにリチウムイオンが吸蔵された層間化合物は有機溶媒
に対する反応性が高く、電解液を分解し負極とはなり得
なかったが、ＰＣ／ＥＣ、ＰＣ／ＤＭＥ、あるいは、γ
−ＢＬを含有してなる混合溶媒系など、グラファイトに
適した電解液を用いると、吸蔵されるリチウム量の大き
い負極になる。すなわち、多孔質負極を構成する活物質
の炭素質材料に結晶構造の発達した黒鉛質粒子を適した
電解液系との組み合わせで用いると、高容量な二次電池
となる。[0006] In these patents, propylene carbonate (hereinafter abbreviated as PC) is used as an organic solvent.
Tetrahydrofuran (hereinafter abbreviated as THF), γ-
Butyrolactone (hereinafter abbreviated as γ-BL), 1,2
-Dimethoxyethane (hereinafter abbreviated as DME), sulfolane, ethylene carbonate (hereinafter abbreviated as EC) and the like are described. As an example, LiCl
O 4 or LiBF 4, and PC is used as a representative solvent.
Alternatively, THF is used. In an electrolyte using PC as a solvent, J.I. Electrochem. Soc. , 117
P. As described in No. 222 (1970), the intercalation compound in which lithium ions are inserted into graphite has a high reactivity to an organic solvent and cannot decompose an electrolytic solution to become a negative electrode. Or γ
When an electrolytic solution suitable for graphite, such as a mixed solvent system containing -BL, is used, a negative electrode having a large amount of inserted lithium is obtained. That is, when a graphite material having a developed crystal structure is used in combination with a suitable electrolyte solution as a carbonaceous material of an active material constituting a porous negative electrode, a secondary battery having a high capacity can be obtained.
【０００７】ところが、黒鉛構造の発達した粒子を結着
剤などの合剤を用いて多孔質負極を構成し、容積当たり
のエネルギー密度を大きくするために、利用率の大きな
黒鉛質粒子からなる負極活物質の充填密度を上げると、
充放電サイクルの繰り返しにより、内部抵抗が増大し、
電池容量が低下したり、低温出力特性に劣るなどの問題
があった。[0007] However, in order to increase the energy density per volume by forming a porous negative electrode using particles having a developed graphite structure using a mixture such as a binder, a negative electrode comprising graphite particles having a high utilization factor is used. When the packing density of the active material is increased,
Internal resistance increases due to repetition of charge / discharge cycles,
There have been problems such as a decrease in battery capacity and poor low-temperature output characteristics.
【０００８】[0008]
【発明が解決しようとする課題】本発明の課題は二次電
池の容積当たりの高エネルギー密度化のために、利用率
の大きい黒鉛粒子から主として構成される負極活物質の
充填密度が大きく、充放電サイクルの繰り返しによる内
部抵抗の増大を伴わず電池容量の低下の小さい、かつ、
出力特性に優れる特定の空隙構造を有する負極を用いた
高容量な非水二次電池を提供することである。An object of the present invention is to increase the packing density of a negative electrode active material mainly composed of graphite particles having a high utilization factor in order to increase the energy density per volume of a secondary battery. The decrease in battery capacity is small without increasing internal resistance due to repeated discharge cycles, and
An object of the present invention is to provide a high-capacity non-aqueous secondary battery using a negative electrode having a specific void structure having excellent output characteristics.
【０００９】[0009]
【課題を解決するための手段】本発明者等は前記課題を
解決するために、多孔質負極に用いる炭素質材料粒子と
負極の空隙構造を鋭意検討したところ、黒鉛質粒子およ
び非黒鉛質炭素粒子からなり、かつ、特定の空隙構造を
有する負極を用いることで、充放電サイクル性、低温出
力特性に優れた高容量な二次電池となることを見いだ
し、本発明を完成するに至った。Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies on the carbonaceous material particles used for the porous negative electrode and the void structure of the negative electrode. It has been found that the use of a negative electrode composed of particles and having a specific void structure results in a high-capacity secondary battery having excellent charge / discharge cycle characteristics and low-temperature output characteristics, and has completed the present invention.
【００１０】すなわち、本発明は、炭素質材料粒子から
主として構成される多孔質負極と充放電可能な正極と有
機溶媒系電解液からなる非水系二次電池において、上記
炭素質材料粒子が主として炭素網面の面間隔ｄ002 が
０．３３７ｎｍ未満の黒鉛質粒子および炭素網面の面間
隔ｄ002 が０．３３７ｎｍ以上の非黒鉛質炭素粒子から
なり、かつ上記非水二次電池用負極の空孔率が１０〜６
０％で、空孔径０．１〜１０μｍの範囲にある空孔の占
める体積が全空孔体積に対して８０％以上であることを
特徴とする非水二次電池を提供するものである。That is, the present invention relates to a nonaqueous secondary battery comprising a porous negative electrode mainly composed of carbonaceous material particles, a chargeable / dischargeable positive electrode, and an organic solvent-based electrolyte, wherein the carbonaceous material particles are mainly composed of carbonaceous material. The non-aqueous secondary battery negative electrode comprises graphite particles having a net spacing d 002 of less than 0.337 nm and non-graphitic carbon particles having a net spacing d 002 of 0.337 nm or more. Porosity is 10-6
A nonaqueous secondary battery characterized in that the volume occupied by pores having a pore diameter of 0.1 to 10 μm at 0% is 80% or more of the total pore volume.
【００１１】以下、本発明を詳細に説明する。本発明の
二次電池は、主に炭素質材料粒子からなる多孔質負極
と、充放電可能な正極と有機溶媒系電解液から構成され
る。多孔質負極を構成する活物質の炭素質材料に黒鉛構
造の発達した黒鉛質粒子を用いると、Ｌｉ吸蔵量・放出
量の大きな高容量な電池となる。ところが、黒鉛構造の
発達した黒鉛質粒子は、その形状が偏平状、あるいは、
鱗状となり易く、黒鉛質粒子単独で結着剤などの合剤を
用いて多孔質負極を構成し、電池の高容量化のために、
空孔部分を減らして負極活物質の充填密度を上げようと
すると、空孔径の小さい部分の割合が増えるために、充
放電サイクルの繰り返しにより、内部抵抗の増大を伴い
著しく電池容量が低下したり、低温出力特性が低下する
などの問題があった。黒鉛質粒子単独で結着剤などの合
剤を用いて多孔質負極を構成する際に、サイクル性、低
温出力特性の優れた二次電池にするには、空孔径の小さ
い部分が増えないように充填密度を抑えなければなら
ず、高容量化することが困難であった。Hereinafter, the present invention will be described in detail. The secondary battery of the present invention includes a porous negative electrode mainly composed of carbonaceous material particles, a chargeable / dischargeable positive electrode, and an organic solvent-based electrolyte. If graphite particles having a developed graphite structure are used as the carbonaceous material of the active material constituting the porous negative electrode, a high-capacity battery with a large Li occlusion / release amount is obtained. However, graphite particles with a developed graphite structure have a flat shape, or
It is easy to become scale-like, and the graphite negative electrode alone constitutes a porous negative electrode using a mixture such as a binding agent, and in order to increase the capacity of the battery,
When attempting to increase the packing density of the negative electrode active material by reducing the number of vacancies, the percentage of porosity with small pores increases, and the repetition of charge / discharge cycles causes a significant decrease in battery capacity with an increase in internal resistance. And the low-temperature output characteristics are reduced. When constructing a porous negative electrode using a mixture such as a binder alone with graphite particles, in order to make a secondary battery with excellent cycleability and low-temperature output characteristics, the portion with small pore diameter should not increase. Therefore, it was difficult to increase the capacity.
【００１２】本発明の炭素質材料粒子が主として炭素網
面の面間隔ｄ002 が０．３３７ｎｍ未満の黒鉛質粒子お
よび炭素網面の面間隔ｄ002 が０．３３７ｎｍ以上の非
黒鉛質炭素粒子からなる複合負極によれば、負極活物質
の充填密度を上げることができ、サイクル性、低温出力
特性を損なうことなく電池の高容量化がはかれる。本発
明でいう炭素網面の面間隔ｄ002 が０．３３７ｎｍ未満
の黒鉛質粒子とは、炭素網面の層が規則正しく積層され
た黒鉛構造の発達した炭素質材料である。The carbonaceous material particles of the present invention are mainly composed of graphite particles having a carbon mesh plane spacing d 002 of less than 0.337 nm and non-graphitic carbon particles having a carbon mesh plane spacing d 002 of 0.337 nm or more. According to the composite negative electrode, the packing density of the negative electrode active material can be increased, and the capacity of the battery can be increased without impairing the cyclability and the low-temperature output characteristics. The graphite particles having a carbon mesh plane spacing d 002 of less than 0.337 nm as referred to in the present invention are carbonaceous materials having a developed graphite structure in which layers of carbon mesh planes are regularly stacked.
【００１３】炭素質材料はその出発原料及びその処理
（製造）方法により種々の構造を取るが、いずれの材料
も高温処理によりその炭素網面の面間隔ｄ002 は小さく
なり、炭素網面の積層厚みＬｃは大きくなる傾向にあ
り、グラファイトは最も小さい面間隔ｄ002 ＝０．３３
５４ｎｍを持つ。このｄ002 の減少及びＬｃの増加、す
なわち、黒鉛化のし易さは出発原料により大きく異な
り、高温処理（〜３０００℃）で容易に黒鉛化する易黒
鉛化物質と黒鉛化が進行しにくい（ｄ002 が小さくなり
にくい）難黒鉛化物質とに分類される。この炭素質材料
の黒鉛化の際、前記のｄ002 、Ｌｃの他に真密度、比表
面積、電気抵抗等も大きく変化するが、層間化合物の形
成には特に面間隔が重要である。The carbonaceous material has various structures depending on its starting material and its processing (manufacturing) method. However, the high-temperature treatment reduces the plane spacing d 002 of the carbon mesh planes of all the carbonaceous materials. The thickness Lc tends to be large, and graphite has the smallest interplanar spacing d 002 = 0.33
It has 54 nm. The decrease in d 002 and the increase in Lc, that is, the ease of graphitization greatly varies depending on the starting material, and the graphitizable substance that easily graphitizes at high temperature treatment (up to 3000 ° C.) and the graphitization hardly proceed ( d 002 is difficult to be reduced). When the carbonaceous material is graphitized, the true density, the specific surface area, the electrical resistance, and the like greatly change in addition to the above d 002 and Lc, but the interplanar spacing is particularly important for forming the interlayer compound.
【００１４】本発明に用いられるｄ002 が０．３３７ｎ
ｍ未満の黒鉛質粒子は、人造黒鉛、天然に産する黒鉛、
いずれのものであってもよく、また、両者を混合したも
のであってもよい。人造黒鉛は、石油ピッチ、コールタ
ールピッチ、熱分解炭素、ニードルコークス、フリュー
ドコークス、メソフェーズマイクロビーズ、縮合多環炭
化水素などに代表される易黒鉛化性物質を一般に２５０
０℃以上、より好ましくは２８００℃以上で熱処理する
ことで得られる。The d 002 used in the present invention is 0.337 n
m less than graphite particles, artificial graphite, naturally occurring graphite,
Either one may be used, or both may be mixed. Artificial graphite is an easily graphitizable substance represented by petroleum pitch, coal tar pitch, pyrolytic carbon, needle coke, fluid coke, mesophase microbeads, condensed polycyclic hydrocarbons and the like.
It is obtained by heat treatment at 0 ° C. or more, more preferably at 2800 ° C. or more.
【００１５】本発明に用いられる黒鉛質粒子は、その粒
子径が０．１〜１００μｍの範囲に含まれる粒子が９５
重量％以上、好ましくは１〜５０μｍの範囲に含まれる
粒子が９５重量％以上のものが好適に用いられる。０．
１μｍ未満の粒子が含まれていると、表面積が大きくな
り、表面で起こる副反応の量が大きくなり、電流効率の
低下を伴い、電池容量が小さくなる。また、１００μｍ
を越える粗大粒子が含まれると、後述する電極の空隙構
造が適さなくなり、充放電サイクルにより容量低下を起
こす。The graphitic particles used in the present invention have a particle diameter of 95 to 100 μm.
% Or more, preferably 95% by weight or more of particles contained in the range of 1 to 50 μm is suitably used. 0.
When particles having a size of less than 1 μm are included, the surface area increases, the amount of side reactions occurring on the surface increases, and the current efficiency decreases, and the battery capacity decreases. Also, 100 μm
If the particles contain coarse particles having a particle size exceeding the above range, the pore structure of the electrode described below is not suitable, and the capacity is reduced by the charge / discharge cycle.
【００１６】本発明で用いる黒鉛質粒子の炭素網面の積
層厚みＬｃは特に限定するものではないが黒鉛化および
粒子形状に関してＬｃも重要なパラメータであり、好ま
しくは３０ｎｍ以上、更に好ましくは５０ｎｍ以上がよ
い。３０ｎｍ未満ではリチウム吸蔵・放出量（利用率）
が低くなり、好ましくない。またその表面積も特に限定
するものではないが、表面積が大きいと副反応が多く起
こり易くなるため、５０ｍ2 ／ｇ以下がよく、好ましく
は２５ｍ2 ／ｇ以下、さらに好ましくは１５ｍ 2 ／ｇが
よい。但し、１ｍ2 ／ｇ未満では、Ｌｉイオンの出は入
りする界面の面積が少なくなり、電極活物質あたりの電
流密度が大きくなるため好ましくない。The product of the carbon network of the graphitic particles used in the present invention.
The layer thickness Lc is not particularly limited, but may be graphitized and
Lc is also an important parameter for the particle shape, and
30 nm or more, more preferably 50 nm or more.
No. For less than 30 nm, lithium absorption / release (utilization rate)
Is low, which is not preferable. The surface area is also particularly limited
However, if the surface area is large, many side reactions occur.
50m to make it easy to stiffenTwo/ G or less, preferably
Is 25mTwo/ G or less, more preferably 15 m Two/ G
Good. However, 1mTwo/ G, the output of Li ions is
The area of the interface between the electrodes is reduced,
It is not preferable because the flow density increases.
【００１７】本発明の炭素網面の面間隔ｄ002 が０．３
３７ｎｍ以上の非黒鉛質炭素粒子とは、炭素網面の層が
規則正しく積層された黒鉛構造のあまり発達していない
炭素質粒子である。このような炭素質粒子として、例え
ば、コークス、アセチレンブラック、ファーネスブラッ
ク、活性炭、メソフェーズマイクロビーズの炭化物、フ
リュードコークス、ギルソナイトコークス、ニードルコ
ークス、炭素繊維、黒鉛繊維を粉砕したいわゆるミルド
ファイバー等が挙げられる。According to the present invention, the distance d002 between the carbon net surfaces is 0.3
The non-graphitic carbon particles having a size of 37 nm or more are carbonaceous particles having a less developed graphite structure in which layers of a carbon network surface are regularly stacked. Examples of such carbonaceous particles include coke, acetylene black, furnace black, activated carbon, carbide of mesophase microbeads, flue coke, Gilsonite coke, needle coke, carbon fiber, and so-called milled fiber obtained by pulverizing graphite fiber. No.
【００１８】本発明の炭素質材料はｄ002 が０．３３７
ｎｍ未満の黒鉛質粒子が炭素原子当りのリチウム吸蔵量
（利用率）が高く、有効ではあるが、単独では、後述す
る空孔構造を満足する多孔質負極を得難く、ｄ002 が
０．３３７ｎｍ以上である非黒鉛質炭素粒子を混合し
て、複合化することが必須である。非黒鉛質炭素粒子を
混合する割合は特に限定されるものではないが、黒鉛質
粒子１００重量部に対して、非黒鉛質粒子が１重量部以
上１００重量部未満の範囲で混合することが好ましく、
５重量部以上４５重量部未満ではより好ましく、１５重
量部以上３０重量部未満ではさらに好適に用いられる。
非黒鉛質粒子１重量部未満と少ない領域では、前述の空
孔径の小さい部分を減らすことができず、サイクル性お
よび低温出力特性に劣ったものとなる。また、非黒鉛質
粒子１００重量部以上の領域では、リチウム吸蔵量（利
用率）が低くなり、また、電流効率も低くなるので電池
の高容量化の観点から好ましくない。The carbonaceous material of the present invention has d 002 of 0.337.
Graphite particles having a particle size of less than 10 nm have a high lithium occlusion amount (utilization rate) per carbon atom and are effective. However, it is difficult to obtain a porous negative electrode that satisfies the pore structure described below, and d 002 is 0.337 nm. It is essential to mix the above non-graphitic carbon particles to form a composite. The mixing ratio of the non-graphitic carbon particles is not particularly limited, but it is preferable that the non-graphitic particles be mixed in a range of 1 part by weight or more and less than 100 parts by weight with respect to 100 parts by weight of the graphite particles. ,
When it is 5 parts by weight or more and less than 45 parts by weight, it is more preferable, and when it is 15 parts by weight or more and less than 30 parts by weight, it is more suitably used.
In a region as small as less than 1 part by weight of the non-graphitic particles, the above-mentioned portion having a small pore size cannot be reduced, resulting in poor cyclability and low-temperature output characteristics. Further, in the region of 100 parts by weight or more of the non-graphitic particles, the lithium occlusion amount (utilization rate) decreases and the current efficiency also decreases, which is not preferable from the viewpoint of increasing the capacity of the battery.
【００１９】本発明に用いられる非黒鉛質炭素粒子は、
その粒子径が０．１〜１００μｍの範囲に含まれる粒子
が９５重量％以上、好ましくは０．５〜５０μｍの範囲
に含まれる粒子が９５重量％以上のものが好適に用いら
れる。０．１μｍ未満の粒子が含まれていると、表面積
が大きくなり、表面で起こる副反応の量が大きくなり、
電流効率の低下を伴い、電池容量が小さくなるととも
に、後述する電極の空隙構造を満足することができず、
充放電サイクルおよび低温出力特性の劣った電池とな
る。また、１００μｍを越える粗大粒子が多く含まれ
と、後述する電極の空隙構造が適さなくなり、充放電サ
イクルにより容量低下や低温出力特性の劣化を起こす。The non-graphitic carbon particles used in the present invention are:
Particles having a particle diameter in the range of 0.1 to 100 μm are 95% by weight or more, preferably particles in the range of 0.5 to 50 μm are 95% by weight or more. When particles of less than 0.1 μm are included, the surface area increases, the amount of side reactions occurring on the surface increases,
With a decrease in current efficiency, the battery capacity decreases, and the electrode void structure described below cannot be satisfied,
A battery with poor charge / discharge cycle and low-temperature output characteristics is obtained. Further, if a large number of coarse particles exceeding 100 μm are contained, the pore structure of the electrode described later becomes unsuitable, and the charge / discharge cycle causes a reduction in capacity and a deterioration in low-temperature output characteristics.
【００２０】本発明で用いる非黒鉛質炭素粒子の炭素網
面の積層厚みＬｃは特に限定するものではないが、通常
黒鉛化の程度に相関した値となり、好ましくは３０ｎｍ
未満、更に好ましくは１０ｎｍ未満がよい。３０ｎｍ以
上では黒鉛化が発達し、粒子の形状も異方性の発達した
ものとなり、このような非黒鉛質炭素粒子を混合しても
空孔径の小さい部分を減らすことができず、好ましくな
い。またその表面積も特に限定するものではないが、表
面積が大きいと副反応が多く起こり易くなるため、１５
０ｍ2 ／ｇ以下がよく、好ましくは５０ｍ2 ／ｇ以下、
さらに好ましくは２５ｍ2 ／ｇ以下がよい。The laminating thickness Lc of the carbon net surface of the non-graphitic carbon particles used in the present invention is not particularly limited, but usually has a value correlated with the degree of graphitization, and is preferably 30 nm.
Less, more preferably less than 10 nm. If it is 30 nm or more, graphitization develops and the shape of the particles also develops anisotropy. Even if such non-graphitic carbon particles are mixed, the portion having a small pore diameter cannot be reduced, which is not preferable. The surface area is not particularly limited. However, if the surface area is large, many side reactions are likely to occur.
0 m 2 / g or less, preferably 50 m 2 / g or less,
More preferably, it is not more than 25 m 2 / g.
【００２１】本発明でいう負極の空孔率および空孔体積
とは水銀圧入法ポロシメータにより求めらた値である。
炭素質材料の充填密度を上げ電池容量を高める観点か
ら、この空孔率は低く抑えるほうが良いと考えられる
が、炭素質材料粒子を用いて空孔率を６０％以下とした
負極では、低温放電時や高率放電時の電池容量が低下す
る問題が起こる。The porosity and vacancy volume of the negative electrode in the present invention are values determined by a mercury intrusion porosimeter.
From the viewpoint of increasing the packing density of the carbonaceous material and increasing the battery capacity, it is considered better to keep the porosity low. However, in the negative electrode in which the porosity is reduced to 60% or less using carbonaceous material particles, low-temperature discharge is performed. At the time of high-rate discharge or at a high rate of discharge.
【００２２】しかしながら、負極空孔径０．１〜１０μ
ｍの範囲にある空孔体積の全空孔体積に対する百分率を
８０％以上とした本発明の負極を用いると、空孔率を６
０％以下とした負極であっても低温放電時や高率放電時
の電池容量の低下が起こりにくいことを見い出した。こ
の理由は定かではないが、空孔径の小さい部分の電極で
は、初期の充放電サイクルの充電時に副反応で形成され
る生成物が表面に付着あるいは表面近傍の電解液中にあ
り、微細な穴を塞ぎ、リチウムイオンの移動を妨げてい
るのではないかと推定している。また、空孔径１０μｍ
以上の部分が多くなると、電解液の保液性が悪くなるせ
いか、充放電サイクルにより容量が低下するので、好ま
しくない。このような観点から、、空孔径０．１〜１０
μｍの範囲にある空孔の占める体積の全空孔体積に対す
る百分率が８０％以上、かつ、空孔率が１０〜６０％で
ある負極とすると低温放電時や高率放電時の電池容量の
低下を起こすことなく、容量の大きな二次電池となる。
好ましくは、空孔径０．５〜１０μｍの範囲にある空孔
の占める体積の全空孔体積に対する百分率が８０％以上
かつ空孔率が１０〜５０％、さらに好ましくは、空孔径
０．５〜１０μｍの範囲にある空孔の占める体積の全空
孔体積に対する百分率が９０％以上かつ空孔率が２５〜
４０％である。However, the negative electrode has a pore diameter of 0.1 to 10 μm.
When the negative electrode of the present invention is used in which the percentage of the total volume of the pore volume in the range of m is 80% or more, the porosity is 6%.
It has been found that even with a negative electrode of 0% or less, a decrease in battery capacity during low-temperature discharge or high-rate discharge hardly occurs. The reason for this is not clear, but in the electrode with a small pore size, products formed by side reactions during charging in the initial charge-discharge cycle adhere to the surface or are in the electrolyte near the surface, and the fine pores It is estimated that they block the movement of lithium ions. In addition, the pore diameter is 10 μm
An increase in the number of the above portions is not preferable because the capacity decreases due to charge / discharge cycles, probably due to poor liquid retention of the electrolytic solution. From such a viewpoint, the pore diameter is 0.1 to 10
If the percentage of the volume occupied by the pores in the range of μm to the total pore volume is 80% or more and the negative electrode has a porosity of 10 to 60%, the battery capacity decreases during low-temperature discharge or high-rate discharge. A secondary battery having a large capacity can be obtained without causing the problem.
Preferably, the percentage of the volume occupied by pores having a pore diameter in the range of 0.5 to 10 μm to the total pore volume is 80% or more and the porosity is 10 to 50%, and more preferably, the pore diameter is 0.5 to 50%. The percentage of the volume occupied by the pores in the range of 10 μm to the total pore volume is 90% or more and the porosity is 25 to
40%.
【００２３】限られた容積のケースに電極を詰め込む電
池では、この負極の空孔率を低く抑え電極活物質の充填
密度を上げることは電池の容量に大きく影響する。本発
明の主に黒鉛質粒子および非黒鉛質炭素粒子を用いて電
極を構成する際、集電体、合剤等を用いることがある
が、集電体としてはＣｕ、Ｎｉ等が、合剤としてはテフ
ロン、ポリエチレン、ニトリルゴム、ポリブタジエン、
ブチルゴム、ポリスチレン、スチレン／ブタジエンゴ
ム、多硫化ゴム、ニトロセルロース、シアノエチルセル
ロース及びアクリロニトリル、フッ化ビニル、フッ化ビ
ニリデン、クロロプレン等の重合体などが、炭素質材料
粒子に対して２０重量％未満の範囲で用いられる。In a battery in which electrodes are packed in a case having a limited capacity, increasing the packing density of the electrode active material while keeping the porosity of the negative electrode low greatly affects the capacity of the battery. When the electrode is mainly composed of the graphite particles and the non-graphitic carbon particles of the present invention, a current collector, a mixture, and the like may be used. As the current collector, Cu, Ni, or the like is used. As Teflon, polyethylene, nitrile rubber, polybutadiene,
Butyl rubber, polystyrene, styrene / butadiene rubber, polysulfide rubber, nitrocellulose, cyanoethylcellulose, polymers such as acrylonitrile, vinyl fluoride, vinylidene fluoride, chloroprene, etc. in a range of less than 20% by weight based on the carbonaceous material particles. Used in
【００２４】またこの電極を形成する方法として電極活
物質と有機重合体を混合し、圧縮成型する方法、有機重
合体の溶剤溶液に電極活物質を分散したのち、塗工乾燥
する方法、有機重合体の水性あるいは油性分散体に電極
活物質を分散した後、塗工乾燥する方法等が知られてい
るが、特に限定するものではないが、バインダーの分布
が不均一になると好ましくないので、好ましくは有機重
合体の水性あるいは油性分散体に電極活物質を分散した
後、塗工乾燥する方法、更に好ましくは有機重合体に
０．５μｍ以下の粒子を含む非フッ素系有機重合体を用
いるのがよい。As a method of forming the electrode, a method of mixing the electrode active material and the organic polymer and compression molding, a method of dispersing the electrode active material in a solvent solution of the organic polymer, coating and drying, and a method of forming an organic polymer. After dispersing the electrode active material in the combined aqueous or oily dispersion, a method of coating and drying is known, but is not particularly limited, but it is not preferable if the distribution of the binder becomes non-uniform. After dispersing the electrode active material in an aqueous or oily dispersion of an organic polymer, a method of coating and drying, more preferably using a non-fluorinated organic polymer containing particles of 0.5 μm or less in the organic polymer. Good.
【００２５】塗工乾燥する方法では、分散体の抜けた部
分で空隙を生じ、電極活物質の充填密度が低くなり易
い。このような欠点を解消する方法として、塗工液の固
形分の割合を高くし、分散体の割合を減らして塗工乾燥
時の電極活物質の充填密度を上げたり、要すれば、塗工
乾燥後の電極をプレスしてもよい。但し、プレスをし過
ぎると本発明の空孔分布が不適になるため、適度なプレ
スをすることが重要であることは言うまでもない。In the method of coating and drying, voids are formed in the portion where the dispersion has come off, and the packing density of the electrode active material tends to be low. As a method of solving such a defect, the solid content of the coating solution is increased, the dispersion ratio is reduced to increase the filling density of the electrode active material at the time of coating and drying, or if necessary, the coating is performed. The dried electrode may be pressed. However, it is needless to say that it is important to perform an appropriate press because the pore distribution of the present invention becomes inappropriate if the press is performed too much.
【００２６】本発明の二次電池を構成する電解液の溶媒
は、プロピレンカーボネート単一溶媒系の電解液では前
述の如く黒鉛質負極で分解されるので用いることはでき
ず、通常グラファイト負極で安定に用いられるものが好
ましい。このような電解液溶媒として、例えば、５員環
の環状エステル類、鎖状エステル類、環状カーボネート
類、鎖状カーボネート類、環状エーテル類、鎖状エーテ
ル類、ケトン類、ニトリル類、アミド類、スルホン系化
合物、芳香族炭化水素類、りん酸エステル類などが挙げ
られる。また、これらの溶媒の２種以上を混合して用い
ることもできる。これらの中でも、黒鉛質粒子の性能を
安定に発揮させるために、５員環の環状エステル類を１
０体積％以上９５体積％未満含有し、主として環状カー
ボネート類と組み合わせた混合溶媒系電解液を用いるこ
とが好ましい。さらに好ましくは、５員環の環状エステ
ル類を２０体積％以上８０体積％未満含有し、主として
環状カーボネート類と組み合わせた混合溶媒系電解液を
用いるものである。５員環の環状エステル類として、例
えば、γ−ＢＬ、γ−バレロラクトンなどから選ばれた
１種あるいは２種が挙げられる。環状カーボネート類と
して、例えば、エチレンカーボネート、プロピレンカー
ボネート、シクロヘキシルカーボネートなどから選ばれ
た１種あるいは２種以上が挙げられる。The solvent of the electrolyte constituting the secondary battery of the present invention cannot be used in the case of a propylene carbonate single solvent-based electrolyte because it is decomposed by the graphite negative electrode as described above. Are preferably used. Examples of such an electrolyte solution solvent include 5-membered cyclic esters, chain esters, cyclic carbonates, chain carbonates, cyclic ethers, chain ethers, ketones, nitriles, amides, Examples thereof include sulfone compounds, aromatic hydrocarbons, and phosphate esters. In addition, two or more of these solvents can be used as a mixture. Among them, in order to stably exhibit the performance of the graphitic particles, a 5-membered ring cyclic ester is used.
It is preferable to use a mixed solvent-based electrolytic solution containing 0% by volume or more and less than 95% by volume and mainly combined with cyclic carbonates. More preferably, a mixed solvent-based electrolyte containing 20% by volume or more and less than 80% by volume of a 5-membered cyclic ester and mainly combined with a cyclic carbonate is used. Examples of the 5-membered cyclic ester include one or two selected from γ-BL, γ-valerolactone, and the like. Examples of the cyclic carbonates include one or more selected from ethylene carbonate, propylene carbonate, cyclohexyl carbonate, and the like.
【００２７】これらの溶媒以外の第３成分として、例え
ば、環状エステル類、鎖状エステル類、鎖状カーボネー
ト類、環状エーテル類、鎖状エーテル類、ケトン類、ニ
トリル類、アミド類、スルホン系化合物、芳香族炭化水
素類、りん酸エステル類などから選ばれた１種あるいは
２種以上の混合物が挙げられる。これらの具体例として
は、ブチレンカーボネート、ジメトキシエタン、テトラ
ヒドロフラン、２−メチル−テトラヒドロフラン、アニ
ソール、１，４−ジオキサン、４−メチル−２−ペンタ
ノン、シクロヘキサノン、アセトニトリル、プロピオニ
トリル、ブチロニトリル、ジエチルカーボネート、ジメ
チルホルムアミド、ジメチルアセトアミド、ジメチルス
ルホキシド、スルホラン、蟻酸メチル、蟻酸エチル、酢
酸メチル、酢酸エチル、酢酸プロピル、酢酸ブチル、プ
ロピオン酸エチル、ベンゼン、トルエン、キシレン、り
ん酸トリメチル、りん酸トリエチル、りん酸トリプロピ
ル、りん酸トリブチル、りん酸トリオクチルなどが挙げ
られる。As the third component other than these solvents, for example, cyclic esters, chain esters, chain carbonates, cyclic ethers, chain ethers, ketones, nitriles, amides, sulfone compounds And one or a mixture of two or more selected from aromatic hydrocarbons, phosphates and the like. Specific examples of these include butylene carbonate, dimethoxyethane, tetrahydrofuran, 2-methyl-tetrahydrofuran, anisole, 1,4-dioxane, 4-methyl-2-pentanone, cyclohexanone, acetonitrile, propionitrile, butyronitrile, diethyl carbonate, Dimethylformamide, dimethylacetamide, dimethylsulfoxide, sulfolane, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, benzene, toluene, xylene, trimethyl phosphate, triethyl phosphate, triethyl phosphate Propyl, tributyl phosphate, trioctyl phosphate and the like.
【００２８】本発明の二次電池の電解液の溶質は、主と
してアルカリ金属塩から構成される。その具体例とし
て、ＬｉＢＦ4 、ＬｉＡｓＦ6 、ＬｉＰＦ6 、ＬｉＣｌ
Ｏ4 、ＣＦ3 ＳＯ3 Ｌｉ、ＬｉＩ、ＬｉＡｌＣｌ4 、Ｎ
ａＣｌＯ4 、ＮａＢＦ4 、ＮａＩ、ＫＰＦ6 などが挙げ
られる。また、これらの電解質を混合して用いたり、
（ｎ−Ｂｕ）4 ＮＣｌＯ4 、（ｎ−Ｂｕ）4 ＮＢＦ4 な
どのアンモニウム塩を添加して用いてもよい。これらの
中でも、電池性能及び取扱上の安全性や毒性などの観点
からＬｉＢＦ4 、ＬｉＰＦ6 を主体とした溶質が好まし
い。The solute of the electrolytic solution of the secondary battery of the present invention is mainly composed of an alkali metal salt. As specific examples, LiBF 4 , LiAsF 6 , LiPF 6 , LiCl
O 4 , CF 3 SO 3 Li, LiI, LiAlCl 4 , N
aClO 4 , NaBF 4 , NaI, KPF 6 and the like. In addition, these electrolytes may be mixed and used,
An ammonium salt such as (n-Bu) 4 NClO 4 or (n-Bu) 4 NBF 4 may be added and used. Among these, a solute mainly composed of LiBF 4 and LiPF 6 is preferable from the viewpoints of battery performance, safety in handling and toxicity.
【００２９】本発明の負極と組み合わされる正極として
は特に限定される物ではないが、ＭｎＯ2 、ＭｏＯ3 、
Ｖ2 Ｏ5 、Ｖ6 Ｏ13、Ｆｅ2 Ｏ3 、Ｆｅ3 Ｏ4 、リチウ
ム含有遷移金属カルコゲン化合物、ＴｉＳ2 、Ｍｏ
Ｓ3 、ＦｅＳ2 、ＣｕＦ2 、ＮｉＦ2 等の無機化合物、
フッ化カーボン、グラファイト、気相成長炭素繊維及び
／またはその粉砕物、ピッチ系炭素繊維及び／またはそ
の粉砕物等の炭素材料、ポリアセチレン、ポリ−ｐ−フ
ェニレン等の導電性高分子等があげられる。The positive electrode to be combined with the negative electrode of the present invention is not particularly limited, but includes MnO 2 , MoO 3 ,
V 2 O 5 , V 6 O 13 , Fe 2 O 3 , Fe 3 O 4 , lithium-containing transition metal chalcogen compound, TiS 2 , Mo
Inorganic compounds such as S 3 , FeS 2 , CuF 2 , NiF 2 ,
Examples of the material include carbon materials such as carbon fluoride, graphite, vapor grown carbon fiber and / or pulverized product thereof, pitch-based carbon fiber and / or pulverized product thereof, and conductive polymers such as polyacetylene and poly-p-phenylene. .
【００３０】リチウムを含まない正極に対しては本発明
の負極にリチウムを吸蔵させて用いる、あるいは本発明
の負極に必要量の金属リチウムを接合して用いるなどし
て電池を組むことが出来る。しかし、このような電池は
組立時に不活性ガス下で組み立てることが必要になるな
ど、組立工程が煩雑となる。リチウムを含有する遷移金
属カルコゲン化合物を用いた場合、正極、負極共に空気
中で安定な放電状態で電池を組み立てることができ、加
工、組立の制約が少なく、更に電池の短絡等による発
熱、爆発等の危険性がなく、安全上からも好ましい。For a positive electrode containing no lithium, a battery can be assembled by using the negative electrode of the present invention by absorbing lithium, or by bonding a required amount of metallic lithium to the negative electrode of the present invention. However, such a battery requires assembly under an inert gas at the time of assembly, and the assembly process becomes complicated. When a transition metal chalcogen compound containing lithium is used, the battery can be assembled in a stable discharge state in air for both the positive electrode and the negative electrode, and there are few restrictions on processing and assembly, and furthermore, heat generation, explosion, etc. due to short-circuiting of the battery, etc. It is preferable from the viewpoint of safety because there is no danger.
【００３１】このようなリチウム含有遷移金属カルコゲ
ン化合物としては、たとえばＬｉ(1 -X) ＣｏＯ2 、Ｌｉ
(1-x) ＮｉＯ2 、Ｌｉ(1-x) Ｃｏ(1-y) Ｎｉy Ｏ2 、Ｌ
ｉＭｎ2 Ｏ4 、Ｌｉ(1-X) Ｃｏ(1-Y) ＭY Ｏ2 （ＭはＣ
ｏ、Ｎｉ以外の遷移金属、Ａｌ、Ｉｎ、Ｓｎ等を表
す）、Ｌｉ(1-X) ＡZ Ｃｏ(1-Y) ＭY Ｏ2 （ＡはＬｉ以
外のアルカリ金属）が挙げられる。Such lithium-containing transition metal chalcogen compounds include, for example, Li (1- X) CoO 2 , Li
(1-x) NiO 2 , Li (1-x) Co (1-y) Ni y O 2 , L
iMn 2 O 4 , Li (1-X) Co (1-Y) M Y O 2 (M is C
o, represents a transition metal other than Ni, Al, In, Sn, etc.), Li (1-X) A Z Co (1-Y) M Y O 2 (A is alkali metal) other than Li.
【００３２】又、電池の構成要素として、要すればセパ
レーター、端子、絶縁板等の部品が用いられる。電池構
造は特に限定されるものではないが、高率放電時、低温
放電時の容量低下を少なくするためには、スパイラル構
造や積層構造とし、電極面積を大きくして、単位電極面
積あたりの電流密度を小さくする抑えることが好まし
い。If necessary, components such as a separator, a terminal and an insulating plate are used as components of the battery. The battery structure is not particularly limited.However, in order to reduce the capacity decrease during high-rate discharge and low-temperature discharge, a spiral structure or a stacked structure is used, and the electrode area is increased to increase the current per unit electrode area. It is preferable to keep the density low.
【００３３】[0033]
【実施例】以下実施例、比較例により本発明を更に詳し
く説明するがこれに限定されるものではない。炭素質材
料のｄ002 、Ｌｃは「日本学術振興会法」に準じてＸ線
回折の００２ピークより求めた。尚、電流効率は放電電
気量／充電電気量、利用率は放電電気量／負極活物質重
量当りの電気量（１２ｇを９６４８５クーロンとす
る）、として算出した。The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but it should not be construed that the invention is limited thereto. The d002 and Lc of the carbonaceous material were determined from the 002 peak of X-ray diffraction according to the "Japan Society for the Promotion of Science". The current efficiency was calculated as the amount of discharged electricity / the amount of charged electricity, and the utilization was calculated as the amount of discharged electricity / the amount of electricity per negative electrode active material weight (12 g is assumed to be 96485 coulombs).
【００３４】〔実施例１〕鱗状の人造黒鉛（ｄ002 ＝
０．３３５５ｎｍ、平均粒径１５μｍ、粒度範囲１〜５
０μｍ、Ｌｃ＞１００ｎｍ、Ｎ2 吸着によるＢＥＴ表面
積＝１５ｍ2 ／ｇ）１００重量部に対し、カーボンブラ
ック（ｄ002 ＝０．３６７ｎｍ、平均粒径０．３μｍ、
粒度範囲０．１〜１０μｍ、Ｌｃ＜２ｎｍ、Ｎ2 吸着に
よるＢＥＴ表面積＝８ｍ2 ／ｇ）２０重量部、スチレン
／ブタジエンラテックス（旭化成工業（株）製 Ｌ１５
７１）（固形分４８重量％）６重量部、増粘剤としてカ
ルボキシメチルセルロース（第一工業製薬社製 ＢＳＨ
１２）水溶液（固形分１重量％）１６０重量部、水１５
重量部を加え混合し、塗工液とした。１８μｍの銅箔を
基材としてこの塗工液を塗布乾燥した後、油圧４０ｋｇ
／ｃｍ2 に設定したカレンダーロールに３回通してプレ
ス成形し、厚さ８３μｍ、塗工部目付け９０ｇ／ｍ2 の
負極を得た。この負極の空孔率、空孔径分布を水銀圧入
式のポロシメータ（島津製作所（株）製、ポアサイザ９
３２０）を用いて測定したところ、空孔率は３５％、空
孔径０．１〜１０μｍの範囲にある空孔の体積百分率は
９３％、空孔径０．５〜１０μｍの範囲にある空孔の体
積百分率は９１％であった。Example 1 Scale-like artificial graphite (d 002 =
0.3355 nm, average particle size 15 μm, particle size range 1-5
0 μm, Lc> 100 nm, BET surface area by N 2 adsorption = 15 m 2 / g) 100 parts by weight, carbon black (d 002 = 0.367 nm, average particle size 0.3 μm,
Particle size range: 0.1 to 10 μm, Lc <2 nm, BET surface area by N 2 adsorption = 8 m 2 / g) 20 parts by weight, styrene / butadiene latex (L15 manufactured by Asahi Chemical Industry Co., Ltd.)
71) 6 parts by weight of solid content (48% by weight), carboxymethylcellulose (BSH manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as a thickener
12) 160 parts by weight of aqueous solution (solid content 1% by weight), water 15
A part by weight was added and mixed to obtain a coating liquid. After applying and drying this coating liquid using a copper foil of 18 μm as a base material, a hydraulic pressure of 40 kg
/ Cm 2 , and pressed through a calender roll three times to obtain a negative electrode having a thickness of 83 μm and a coating weight of 90 g / m 2 . The porosity and pore size distribution of the negative electrode were measured using a mercury intrusion porosimeter (Poresizer 9 manufactured by Shimadzu Corporation).
320), the porosity was 35%, the volume percentage of pores having a pore diameter in the range of 0.1 to 10 μm was 93%, and the pore percentage was 0.5% to 10 μm. The volume percentage was 91%.
【００３５】平均粒径３μｍのＬｉＣｏＳｎ0.02Ｏ2 １
００重量部に対し、導電フィラーとしてグラファイト
（Ｌｏｎｔｚ社製 商品名ＫＳ６）２０重量部、バイン
ダーとしてポリフッカビニリデン５重量％ジメチルホル
ムアミド溶液１００重量部を加え混合して調製した塗工
液を用い、１５μｍＡｌ箔を基材としてこの塗工液を塗
布乾燥し、厚さ１４０μｍの正極電極を得た。LiCoSn 0.02 O 2 1 having an average particle size of 3 μm
A coating solution prepared by adding and mixing 20 parts by weight of graphite (KS6, trade name, manufactured by Lonz) and 100 parts by weight of a 5% by weight of polyfukkavinylidene solution as a binder with respect to 00 parts by weight and 100 parts by weight of a binder was used. This coating liquid was applied and dried using a foil as a base material to obtain a positive electrode having a thickness of 140 μm.
【００３６】上記正極１、負極２をセパレータとしての
ポリエチレン製微多孔膜３を介してスパイラル状に捲回
し、１ＭのＬｉＢＦ4 をγ−ＢＬ＋ＥＣ＋ＰＣ（容積比
４０：３０：３０）混合溶媒に溶解した電解液を含浸さ
せて図１に示す電池を組み立てた。なお、図１におい
て、４はケース体（負極）、５はハーメチックピン（正
極）、６はレーザー封口である。The positive electrode 1 and the negative electrode 2 are spirally wound through a polyethylene microporous film 3 as a separator, and 1M LiBF 4 is dissolved in a mixed solvent of γ-BL + EC + PC (volume ratio: 40:30:30). The battery shown in FIG. 1 was assembled by impregnating the electrolyte. In FIG. 1, reference numeral 4 denotes a case body (negative electrode), 5 denotes a hermetic pin (positive electrode), and 6 denotes a laser seal.
【００３７】この電池を室温において０．５Ａで４．２
Ｖまで定電流／定電圧充電し、０．５Ａで２．７Ｖまで
定電流で放電するサイクルを繰り返した。この電池の初
回充放電における電流効率は８０％、初回の放電容量は
８６０ｍＡｈであった。２サイクルめ以降の電流効率は
９７％を越え、１０サイクルめの電流効率は９９．６％
であった。途中５０サイクルめで、電流値を１Ａに上げ
て放電したところ、放電容量は初回の８０％以上を保持
していた。さらに、室温での充放電サイクルを繰り返
し、５５サイクルめで、温度を−１０℃に下げて放電し
たところ、その放電容量は初回の約６０％であった。The battery was charged to 4.2 at 0.5 A at room temperature.
A cycle of constant current / constant voltage charging up to V and discharging at 0.5 A at a constant current up to 2.7 V was repeated. The current efficiency in the initial charge and discharge of this battery was 80%, and the initial discharge capacity was 860 mAh. The current efficiency after the second cycle exceeds 97%, and the current efficiency after the 10th cycle is 99.6%
Met. At the 50th cycle on the way, when the current was increased to 1 A and the battery was discharged, the discharge capacity was maintained at 80% or more of the initial discharge capacity. Further, the charge / discharge cycle at room temperature was repeated, and at the 55th cycle, the temperature was lowered to −10 ° C. and the discharge was performed. As a result, the discharge capacity was about 60% of the initial capacity.
【００３８】〔比較例１〕実施例１に用いた鱗状の人造
黒鉛１００重量部とカーボンブラック２０重量部のかわ
りに実施例１の鱗状の人造黒鉛のみを１２０重量部を用
いた以外、実施例１と同様にして負極を作成し、厚さ８
７μｍ、塗工部目付け９０ｇ／ｍ2 の負極を得た。この
負極の空孔率は３９％であり、空孔径０．１〜１０μｍ
までの範囲にある空孔の体積百分率は７８％、空孔径
０．５〜１０μｍの範囲にある空孔の体積百分率は７５
％であった。この負極を用いて実施例１と同様な電池を
組み立て、充放電させたところ、初回の電流効率、電池
容量はそれぞれ７６％、６９０ｍＡｈであった。５０サ
イクルめで実施例１と同様に室温１Ａ放電させたとこ
ろ、放電容量は１サイクルめの容量の３０％以下であっ
た。また、５５サイクルめで、実施例１と同様に−１０
℃放電させたところ、その放電容量は１サイクルめの容
量の３０％未満であった。Comparative Example 1 The procedure of Example 1 was repeated except that only 100 parts by weight of the scale-like artificial graphite used in Example 1 and 120 parts by weight of the scale-like artificial graphite of Example 1 were used instead of 20 parts by weight of carbon black. A negative electrode was prepared in the same manner as in Example 1 and had a thickness of 8
A negative electrode having a thickness of 7 μm and a coating weight of 90 g / m 2 was obtained. The porosity of this negative electrode is 39%, and the pore diameter is 0.1 to 10 μm.
The volume percentage of pores in the range of up to 78% is 78%, and the volume percentage of pores in the range of pore diameter of 0.5 to 10 μm is 75%.
%Met. A battery similar to that of Example 1 was assembled using this negative electrode and charged and discharged. The initial current efficiency and battery capacity were 76% and 690 mAh, respectively. When discharge was performed at room temperature at 1 A in the 50th cycle in the same manner as in Example 1, the discharge capacity was 30% or less of the capacity in the first cycle. Further, at the 55th cycle, −10 as in the first embodiment.
C., the discharge capacity was less than 30% of the capacity in the first cycle.
【００３９】[0039]
【発明の効果】本発明の炭素質材料粒子が主として炭素
網面の面間隔ｄ002 が０．３３７ｎｍ未満の黒鉛質粒
子、および、炭素網面の面間隔ｄ002 が０．３３７ｎｍ
以上の非黒鉛質炭素粒子からなり、かつ、該多孔質負極
の空孔率が１０〜６０％、かつ、空孔径０．１〜１０μ
ｍの範囲にある空孔の占める体積の全空孔体積に対する
百分率が８０％以上である多孔質負極を用いると、電流
効率、利用率が大きく、かつサイクル性、低温特性の優
れた二次電池用負極が得られる。According to the present invention, the carbonaceous material particles of the present invention are mainly graphite particles having a carbon mesh plane spacing d 002 of less than 0.337 nm, and a carbon mesh plane spacing d 002 of 0.337 nm.
The porous negative electrode is composed of the above non-graphitic carbon particles, and has a porosity of 10 to 60% and a pore diameter of 0.1 to 10 μm.
When a porous negative electrode in which the percentage of the volume occupied by pores in the range of m to the total pore volume is 80% or more is used, a secondary battery with high current efficiency, high utilization, excellent cycleability, and low-temperature characteristics is used. A negative electrode is obtained.
【図１】図１は本発明の電池の構成例の説明図である。FIG. 1 is an explanatory diagram of a configuration example of a battery of the present invention.
１ 正極 ２ 負極 ３ セパレータ ４ ケース（負極） ５ ハーメチックピン（正極） ６ レーザー封口 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 4 Case (negative electrode) 5 Hermetic pin (positive electrode) 6 Laser sealing
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平６−231766（ＪＰ，Ａ) 特開 平５−290833（ＪＰ，Ａ) 特開 平６−267590（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/02 - 4/04 H01M 4/58 H01M 10/40 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-231766 (JP, A) JP-A-5-290833 (JP, A) JP-A-6-267590 (JP, A) (58) Field (Int.Cl. 7 , DB name) H01M 4/02-4/04 H01M 4/58 H01M 10/40
Claims (2)
多孔質負極と充放電可能な正極と有機溶媒系電解液から
なる非水系二次電池において、上記炭素質材料粒子が、
炭素網面の面間隔ｄ002 が０．３３７ｎｍ未満の黒鉛質
粒子、および、炭素網面の面間隔ｄ002 が０．３３７ｎ
ｍ以上の非黒鉛質炭素粒子からなり、かつ上記多孔質負
極の空孔率が１０〜６０％で、空孔径０．１〜１０μｍ
の範囲にある空孔の占める体積が全空孔体積に対して８
０％以上であることを特徴とする非水二次電池。1. A non-aqueous secondary battery comprising a porous negative electrode mainly composed of carbonaceous material particles, a chargeable / dischargeable positive electrode, and an organic solvent-based electrolyte, wherein the carbonaceous material particles are:
Graphite particles having a carbon mesh plane spacing d 002 of less than 0.337 nm, and a carbon network plane spacing d 002 of 0.337 n
m of non-graphitic carbon particles having a porosity of 10 to 60% and a pore diameter of 0.1 to 10 μm.
The volume occupied by pores in the range of
Non-aqueous secondary battery characterized by being at least 0%.
員環の環状エステル類１０容積％以上９５容積％未満お
よび環状カーボネート類、溶質として主にアルカリ金属
塩からなる電解液であることを特徴とする請求項１に記
載の非水二次電池。2. An organic solvent-based electrolyte mainly comprising 5
2. The non-aqueous secondary battery according to claim 1, wherein the electrolyte is an electrolyte containing 10% by volume or more and less than 95% by volume of a membered cyclic ester, a cyclic carbonate, and an alkali metal salt as a solute.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08065093A JP3236400B2 (en) | 1993-04-07 | 1993-04-07 | Non-aqueous secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08065093A JP3236400B2 (en) | 1993-04-07 | 1993-04-07 | Non-aqueous secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06295744A JPH06295744A (en) | 1994-10-21 |
| JP3236400B2 true JP3236400B2 (en) | 2001-12-10 |
Family
ID=13724246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08065093A Expired - Lifetime JP3236400B2 (en) | 1993-04-07 | 1993-04-07 | Non-aqueous secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3236400B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6440407B1 (en) | 1992-11-24 | 2002-08-27 | G. D. Searle | Methods of ex-vivo expansion of hematopoietic cells using interleukin-3 (IL-3) multiple mutation polypeptides |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1995026057A1 (en) * | 1994-03-19 | 1995-09-28 | Hitachi Maxell, Ltd. | Organic-electrolyte secondary battery |
| JP3239067B2 (en) * | 1996-05-27 | 2001-12-17 | 三洋電機株式会社 | Lithium battery |
| CN1275341C (en) * | 1996-08-08 | 2006-09-13 | 日立化成工业株式会社 | Negative-pole producing method for lithium secondary cell |
| WO1999060652A1 (en) | 1998-05-20 | 1999-11-25 | Osaka Gas Company Limited | Nonaqueous secondary cell and method for controlling the same |
| JP2004022512A (en) * | 2002-06-20 | 2004-01-22 | Sony Corp | Negative electrode material and battery using the same |
| CA2394056A1 (en) * | 2002-07-12 | 2004-01-12 | Hydro-Quebec | Particles with a non-conductive or semi-conductive core covered by a conductive layer, the processes for obtaining these particles and their use in electrochemical devices |
| CA2411695A1 (en) | 2002-11-13 | 2004-05-13 | Hydro-Quebec | Electrode covered with a film obtained from an aqueous solution containing a water soluble binder, manufacturing process and usesthereof |
| EP1916734B1 (en) | 2005-08-18 | 2012-05-02 | Ube Industries, Ltd. | Non-aqueous electrolyte solution and lithium secondary battery using the same |
| JP5035281B2 (en) * | 2009-03-23 | 2012-09-26 | 宇部興産株式会社 | Non-aqueous secondary battery |
-
1993
- 1993-04-07 JP JP08065093A patent/JP3236400B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6440407B1 (en) | 1992-11-24 | 2002-08-27 | G. D. Searle | Methods of ex-vivo expansion of hematopoietic cells using interleukin-3 (IL-3) multiple mutation polypeptides |
| US6458931B1 (en) | 1992-11-24 | 2002-10-01 | S. Christopher Bauer | Interleukin-3 (IL-3) multiple mutation polypeptides |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06295744A (en) | 1994-10-21 |
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