JPH0927315A - Nonaqueous secondary battery - Google Patents
Nonaqueous secondary batteryInfo
- Publication number
- JPH0927315A JPH0927315A JP7176088A JP17608895A JPH0927315A JP H0927315 A JPH0927315 A JP H0927315A JP 7176088 A JP7176088 A JP 7176088A JP 17608895 A JP17608895 A JP 17608895A JP H0927315 A JPH0927315 A JP H0927315A
- Authority
- JP
- Japan
- Prior art keywords
- negative electrode
- carbon
- capacity
- secondary battery
- irreversible capacity
- 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.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、携帯用端末機器用電源
としての非水二次電池の小型化高容量化及び長寿命化に
係わり、詳しくはカーボン負極の改良により高容量化と
長寿命化した非水二次電池に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to miniaturization, high capacity and long life of a non-aqueous secondary battery as a power source for portable terminal equipment. To a non-aqueous secondary battery that has been made into
【０００２】[0002]
【従来の技術】Ｌｉ二次電池の負極として、従来はＬｉ
金属及びＬｉ−Ｐｂ等の合金が用いられてきたが、樹枝
状リチウムの析出による正・負極の短絡が起こる事、又
エネルギー密度が低くなるという欠点があった。最近で
は負極としてカーボン材を用いる研究が活発であり、例
えば特公昭６２−２３４３３号、特開昭６２−２６８０
５６号及び特開平５−２８３０６１号公報等の公知例が
ある。特に特開平５−２８３０６１号には炭素粒子と炭
素繊維を複合化した負極構造が開示されている。そし
て、この複合化によって、（１）導電性が大幅に向上
し、充放電反応の速度が向上する、（２）バルキーな構
造となり、負極への電解液の拡散が容易となる気孔が形
成される結果、出力密度が向上する、（３）適度なバル
キーさを持つため電極の膨潤・収縮を吸収でき長寿命化
ができる、（４）炭素粉末・炭素繊維いずれもリチウム
イオンを吸蔵可能なため両者の長所を相補的に生かす事
が出来るとともに、負極当りの放電容量を高める事が出
来るとしている。2. Description of the Related Art Conventionally, as a negative electrode for a Li secondary battery, Li
Metals and alloys such as Li-Pb have been used, but they have the drawbacks that the positive and negative electrodes are short-circuited due to the deposition of dendritic lithium and the energy density is low. Recently, research using a carbon material as a negative electrode has been active, for example, Japanese Patent Publication No. 62-23433 and Japanese Patent Laid-Open No. 62-2680.
There are known examples such as JP-A No. 56 and JP-A-5-283061. In particular, JP-A-5-283061 discloses a negative electrode structure in which carbon particles and carbon fibers are combined. And by this compounding, (1) conductivity is significantly improved, the rate of charge / discharge reaction is improved, and (2) a bulky structure is formed, and pores that facilitate diffusion of the electrolytic solution to the negative electrode are formed. As a result, the output density is improved. (3) Since it has an appropriate bulky property, it can absorb the swelling / shrinking of the electrode and have a long life. (4) Both carbon powder and carbon fiber can store lithium ions. It is said that the advantages of both can be utilized complementarily and the discharge capacity per negative electrode can be increased.
【０００３】しかしながら前述の効果は、導電性を除き
いずれも推定の域を出ない。又負極体作成において、炭
素粉末径：０.１〜１００μｍのものと炭素繊維（径：
１３μｍ、長さ：０.１５〜４０mm）のものを複合化し
た場合、特に実施例で述べられている形状の炭素（中心
粒径２０μｍの炭素粒子：繊維径１３μｍで長さ１５０
μｍの炭素繊維＝８０重量％：２０重量％）の複合化に
よって適度な気孔を形成させるのは困難な事と推察され
る。However, none of the above-mentioned effects is beyond the estimation range except for conductivity. In the production of the negative electrode body, carbon powder having a diameter of 0.1 to 100 μm and carbon fiber (diameter:
When a composite having a size of 13 μm and a length of 0.15 to 40 mm is compounded, carbon having the shape described in the examples (carbon particles having a central particle size of 20 μm: fiber diameter of 13 μm and length of 150) is used.
It is presumed that it is difficult to form appropriate pores by compounding (μm carbon fiber = 80% by weight: 20% by weight).
【０００４】又、いずれの公知例においてもカーボンへ
のＬｉ+ の不可逆容量（第１回目の充放電での充電容量
と放電容量の差の充電容量に対する比）に対しては、何
ら開示されていない。更には負極合剤層構造（細孔径、
細孔容積、気孔率、厚み及び合剤充填密度等）と放電容
量、サイクル特性の関係が明確でなく、小型・高容量・
長寿命非水二次電池の実用化に対してその特性の実証が
十分ではなかった。Further, in any of the known examples, nothing is disclosed about the irreversible capacity of Li + to carbon (the ratio of the difference between the charge capacity and the discharge capacity in the first charge / discharge to the charge capacity). Absent. Furthermore, the negative electrode mixture layer structure (pore size,
Pore volume, porosity, thickness, mixture packing density, etc.) and discharge capacity, cycle characteristics are not clear, and small size, high capacity
The characteristics of the long-life non-aqueous secondary battery have not been sufficiently demonstrated for practical use.
【０００５】[0005]
【発明が解決しようとする課題】前述したごとく、炭素
材をＬｉ二次電池用負極剤として用いたとき単独の炭素
材で負極合剤層を形成した場合、Ｌｉ+ の不可逆容量が
大きい事、又充放電容量の大きい炭素材は、サイクル毎
の容量低下が大きい事、更には合剤層厚みや合剤の充填
密度によって充放電容量が変化するという問題がある。
Ｌｉ二次電池の容量は最初の充電によってＬｉを正極か
ら負極へ移動させ充電状態の正極及び負極とすることに
よって蓄えられる。従って負極の不可逆容量が大きいと
電池の容量密度の低下を引き起こすことになる。これら
の課題を解決することが電池の実用化に望まれている。As described above, when a carbon material is used as a negative electrode agent for a Li secondary battery to form a negative electrode mixture layer with a single carbon material, the irreversible capacity of Li + is large, In addition, a carbon material having a large charge / discharge capacity has a problem that the capacity decreases greatly with each cycle and that the charge / discharge capacity changes depending on the mixture layer thickness and the packing density of the mixture.
The capacity of the Li secondary battery is stored by moving Li from the positive electrode to the negative electrode by the first charge to make the positive electrode and the negative electrode in the charged state. Therefore, if the irreversible capacity of the negative electrode is large, the capacity density of the battery will decrease. Solving these problems is desired for practical use of batteries.
【０００６】以下には、上述の課題を実験的に確かめた
結果について述べる。図４には、平均粒径２０μｍの高
純度黒鉛粒子１と平均繊維径０.２μｍ平均繊維長２０
μｍの気相成長炭素繊維２を用いて作成した負極の充放
電におけるサイクル特性を示す。高純度黒鉛粒子１の場
合、初期充電容量は、例えば４３０ｍＡｈ／ｇ・カーボ
ン（以下Ｃと略記する）であったのに対し、第１回放電
容量は２８０ｍＡｈ／ｇ・Ｃであり、Ｌｉ+ の不可逆容
量は３５％であった。又サイクル毎の放電容量も低下
し、１０サイクル目で１９０ｍＡｈ／ｇ・Ｃまで低下し
た。一方気相成長炭素繊維２の場合、Ｌｉ+ の不可逆容
量は２５％であり、第１回目の放電容量は２００ｍＡｈ
／ｇ・Ｃと低いものの１０サイクル目まで容量低下はほ
とんど見られなかった。The results of experimentally confirming the above problems will be described below. FIG. 4 shows high-purity graphite particles 1 having an average particle size of 20 μm and an average fiber diameter of 0.2 μm and an average fiber length of 20.
3 shows cycle characteristics in charge and discharge of a negative electrode prepared by using vapor-grown carbon fiber 2 of μm. In the case of the high-purity graphite particles 1, the initial charge capacity was, for example, 430 mAh / g.carbon (hereinafter abbreviated as C), whereas the first discharge capacity was 280 mAh / g.C, and the Li + The irreversible capacity was 35%. In addition, the discharge capacity for each cycle also decreased to 190 mAh / g · C at the 10th cycle. On the other hand, in the case of vapor grown carbon fiber 2, the irreversible capacity of Li + is 25% and the discharge capacity of the first time is 200 mAh.
Although it was as low as / g · C, there was almost no decrease in capacity until the 10th cycle.
【０００７】次に、前述したカーボン種によって不可逆
容量やサイクル毎の容量変化が何故生ずるかについて調
べてみた結果について述べる。カーボン負極を用いたと
きのＬｉ+ の不可逆容量を引き起こす要因としては、一
般に（１）溶媒の分解反応、（２）カーボン表面官能基
との反応、（３）カーボン層間からのＬｉ+ の脱離反応
の遅れ等が挙げられる。この不可逆容量とサイクル毎の
容量変化の一要因として負極構造（充填密度、合剤層厚
み、気孔率等）の影響を受けていると考えられる。Next, the results of examining why the irreversible capacity and the capacity change with each cycle are caused by the above carbon species will be described. The factors that cause the irreversible capacity of Li + when using a carbon negative electrode are generally (1) a decomposition reaction of a solvent, (2) a reaction with a carbon surface functional group, (3) desorption of Li + from a carbon layer. Delay of reaction etc. are mentioned. It is considered that the negative electrode structure (filling density, mixture layer thickness, porosity, etc.) influences the irreversible capacity and the capacity change for each cycle.
【０００８】図５には、高純度黒鉛粒子３と炭素繊維４
にバインダーとしてポリフッ化ビニリデン（以下ＰＶＤ
Ｆと略記する）を１０ｗｔ％添加した合剤層に対し、成
型（プレス）圧を変化させたときのかさ密度（合剤層の
重さ／合剤層体積 ｇ／cm3）の変化の測定結果を示し
た。高純度黒鉛３の場合、１ton／cm2〜３ton／cm2のプ
レス圧で１.８５〜２.０ｇ／cm3のかさ密度値に対し、
繊維状炭素４の場合、その特徴的形状から約１ｇ／cm3
と低い値となる。FIG. 5 shows high-purity graphite particles 3 and carbon fibers 4.
Polyvinylidene fluoride as a binder (hereinafter PVD
Measurement of the change in bulk density (weight of mixture layer / volume of mixture layer g / cm 3 ) when the molding (pressing) pressure is changed for the mixture layer containing 10 wt% of F). The results are shown. For high purity graphite 3, with respect to the bulk density values of 1.85~2.0g / cm 3 at a press pressure of 1ton / cm 2 ~3ton / cm 2 ,
In the case of fibrous carbon 4, its characteristic shape is approximately 1 g / cm 3
And a low value.
【０００９】次に合剤層厚みと放電容量の関係を図６に
示した。図中曲線５は、平均粒径２０μｍの人造黒鉛を
用いて作製した負極の合剤層厚みを約１２０〜２５μｍ
に変化させたときの第３回目の放電容量を示している。
図６より明らかなごとく合剤層の密度が一定の場合、厚
みが薄くなると集電効率が向上する結果、放電容量は増
大する傾向にある。Next, the relationship between the mixture layer thickness and the discharge capacity is shown in FIG. The curve 5 in the figure shows the thickness of the mixture layer of the negative electrode prepared using artificial graphite having an average particle size of 20 μm of about 120 to 25 μm.
The discharge capacity of the 3rd time when changing to is shown.
As is clear from FIG. 6, when the density of the mixture layer is constant, the thinner the thickness, the higher the current collection efficiency, and as a result, the discharge capacity tends to increase.
【００１０】又、図７には平均粒径３μｍの高純度黒鉛
を用いて合剤層のかさ密度を変化させた負極の放電容量
を示した。図の曲線６にみられるごとく、かさ密度が
１.２ｇ／cm3付近で放電容量は極大値をもち、その前後
において容量は低下する。FIG. 7 shows the discharge capacity of the negative electrode in which the bulk density of the mixture layer was changed by using high-purity graphite having an average particle size of 3 μm. As can be seen from the curve 6 in the figure, the discharge capacity has a maximum value near the bulk density of 1.2 g / cm 3 , and the capacity decreases before and after that.
【００１１】以上述べたごとく、放電容量の増大、サイ
クル特性の向上及びＬｉ+ の不可逆容量の低減のために
は、負極合剤層の改善が不可欠となる。特にこの種負極
の製造は図８に示した如く、炭素繊維と炭素粒子を混合
し、バインダーを加えて混練し、それを集電体であるＣ
ｕ箔（約２０μｍの厚さ）に塗布し、乾燥させた後、
０．２５〜１．０ton／cm2でプレスするという工程を経
るため、炭素繊維の集電体に対する配向が平行になって
しまい、導電性やエネルギー密度を向上させる上で好ま
しくなく、上記負極構造の改善が必要である。As described above, in order to increase the discharge capacity, improve the cycle characteristics, and reduce the irreversible capacity of Li +, it is essential to improve the negative electrode mixture layer. In particular, as shown in FIG. 8, in order to manufacture this kind of negative electrode, carbon fibers and carbon particles are mixed, a binder is added, and the mixture is kneaded.
After applying to u foil (thickness of about 20 μm) and drying,
Since the step of pressing at 0.25 to 1.0 ton / cm 2 is performed , the orientation of the carbon fibers becomes parallel to the current collector, which is not preferable in improving the conductivity and energy density, and the above-mentioned negative electrode structure. Need improvement.
【００１２】[0012]
【課題を解決するための手段】Ｌｉ+ 二次電池用炭素材
負極について詳細に検討した結果、一種類の炭素を用い
た場合、Ｌｉ+ の不可逆容量が大きいことや放電容量が
大きいもののサイクル毎の容量低下が大きい。Ｌｉ+ の
不可逆容量が小さくサイクル毎の容量低下の小さい炭素
は、放電容量が小さい或いは合剤層厚みや充填密度によ
って放電容量が変化するという課題を明らかにした。こ
れらの事は、炭素材と有機バインダーとから成る負極構
造に基づく電子電導性、Ｌｉ+ のイオン移動度（炭素繊
維の集電体に対する配向に関係する：間接的には、Ｌｉ
+ がドープ、脱ドープするサイトの有効利用）、電解液
の拡散性（粒子間のすき間に関係する）及び負極強度
（グラファイト層間にＬｉ+ が入り、膨潤することによ
りバインダー結合部が弱くなることに対する強度）等の
因子により、その特性が左右されるためと考えた。[Means for Solving the Problems] As a result of detailed examination of a carbon material negative electrode for a Li + secondary battery, when one kind of carbon was used, the Li + irreversible capacity was large and the discharge capacity was large, but The capacity is greatly reduced. It has been clarified that carbon, which has a small irreversible capacity of Li + and a small capacity decrease with each cycle, has a small discharge capacity or the discharge capacity changes depending on the mixture layer thickness and the packing density. These are related to the electron conductivity based on the negative electrode structure composed of the carbon material and the organic binder, the ion mobility of Li + (the orientation of the carbon fiber with respect to the current collector: indirectly, Li
+ Effective use of sites for doping and dedoping), diffusivity of electrolyte (related to gap between particles), and negative electrode strength (Li + enters between graphite layers and swells to weaken the binder bond part) It is thought that the characteristics are influenced by factors such as (strength against).
【００１３】本発明者らは、前記課題を解決するために
は前述した負極構造の最適化が必須であると考え、前述
の実験データを基に異種形状カーボンを特定の比で組合
せることにより、負極合剤層の充填密度、細孔容積、気
孔率及び平均細孔径をコントロールすることを可能と
し、これにより前記諸特性を改善できることを見い出し
た。The inventors of the present invention believe that the above-mentioned optimization of the negative electrode structure is indispensable for solving the above-mentioned problems, and based on the above-mentioned experimental data, by combining differently shaped carbons in a specific ratio, It has been found that it is possible to control the packing density, pore volume, porosity and average pore diameter of the negative electrode mixture layer, and thereby improve the above various characteristics.
【００１４】まず最初に、これまでに至った経緯につい
て述べる。図９は長さの異なる炭素繊維を用いた負極の
放電容量の測定結果を示したものである。以下に本発明
で用いた負極の作成法、単極の評価法の一例について記
述する。図９の曲線７に示した通り、放電容量が極大値
をもつ平均繊維径０.２μｍ、平均繊維長約２０μｍ炭
素材に対して有機バインダーとしてジエチルベンゼン
（以下ＤＥＢと略記）に溶解したエチレンプロピレンタ
ーポリマー（以下ＥＰＤＭと略記する）溶液を炭素材９
４重量％、ＥＰＤＭが６重量％になるように配合したペ
ーストを厚さ２５μｍの銅箔に塗布し、風乾し、空気中
８０℃で３ｈ乾燥後、０.５ton／cm2の圧力で成型す
る。その後、真空中１５０℃で２ｈ熱処理して負極とす
る。この負極とポリプロピレン製のセパレーターとＬｉ
金属対極を組合せ、電解液として１ＭＬiＰＦ6／エチレ
ンカーボネート−ジメトキシエタン（以下ＥＣ−ＤＭＥ
と略記する）、参照極としてＬｉ金属を用い、充放電は
カーボン１ｇ当り３０〜１２０ｍＡ／ｇの電流値、電位
幅：１０ｍＶ〜１．０Ｖでサイクル試験を行い単極評価
を行った。図９において繊維長の異なる炭素材を用いた
負極の特性は約２０μｍの時、最大の放電容量を発現
し、それより短くても長くても容量は低下する傾向にあ
る。これは充填密度の違いによって集電性が大きく影響
していると考えられる。First, the history of the process up to now will be described. FIG. 9 shows the measurement results of the discharge capacity of the negative electrode using carbon fibers having different lengths. Hereinafter, an example of the method for producing the negative electrode and the method for evaluating the single electrode used in the present invention will be described. As shown in the curve 7 of FIG. 9, an average fiber diameter of 0.2 μm and an average fiber length of about 20 μm, which has a maximum discharge capacity, are used for the carbon material. Ethylene propylene tar dissolved in diethylbenzene (hereinafter abbreviated as DEB) as an organic binder. Polymer (hereinafter abbreviated as EPDM) solution is carbon material 9
4% by weight and EPDM of 6% by weight were applied to a 25 μm-thick copper foil, which was air-dried, dried in air at 80 ° C. for 3 hours, and then molded at a pressure of 0.5 ton / cm 2. . Then, it heat-processes at 150 degreeC in vacuum for 2 hours, and makes it a negative electrode. This negative electrode, polypropylene separator and Li
A metal counter electrode is combined and 1 M LiPF 6 / ethylene carbonate-dimethoxyethane (hereinafter referred to as EC-DME) is used as an electrolytic solution.
It is abbreviated), and Li metal was used as a reference electrode, and a charge / discharge was carried out by a cycle test with a current value of 30 to 120 mA / g of carbon per 1 g of carbon and a potential width of 10 mV to 1.0 V to perform a unipolar evaluation. In FIG. 9, the characteristics of the negative electrode using the carbon materials having different fiber lengths show the maximum discharge capacity at about 20 μm, and the capacity tends to decrease at shorter or longer than that. This is considered to be because the difference in packing density has a great influence on current collection.
【００１５】そこで図５に示した形状の異なる炭素材を
混合したときのかさ密度の変化について測定した。その
結果を図１０に示す。図１０で用いた炭素材は、かさ密
度の小さい炭素繊維（平均径：０.２μｍ、平均繊維
長：２０μｍ）とかさ密度の大きい高純度黒鉛粒子（平
均粒径：３μｍ）で、成型圧力は１ton／cm2である。図
１０の直線８より明らかなごとく炭素材単独のかさ密度
に対し、繊維と粒子の双方の炭素を混合することにより
かさ密度を任意に変化させることが可能となる。Therefore, changes in bulk density when carbon materials having different shapes shown in FIG. 5 were mixed were measured. The result is shown in FIG. The carbon material used in FIG. 10 is carbon fiber having a low bulk density (average diameter: 0.2 μm, average fiber length: 20 μm) and high-purity graphite particles having a high bulk density (average particle size: 3 μm). It is 1 ton / cm 2 . As is clear from the straight line 8 in FIG. 10, it is possible to arbitrarily change the bulk density by mixing carbon of both fibers and particles with respect to the bulk density of the carbon material alone.
【００１６】また、ここで得られた混合負極についてポ
ロシメータで測定した細孔容積、気孔率及び平均細孔径
を図１１と図１に示した。図１１の曲線９，１０には、
細孔容積及び気孔率の関係を示している。図１１より繊
維状炭素及び炭素粉末のみで構成した負極の細孔容積、
気孔率が０.３４ｃｃ／ｇ，５７％及び０.１２ｃｃ／
ｇ，４０.８％であるのに対し、任意の割合で混合した
負極の細孔容積及び気孔率は、繊維状炭素と炭素粉末単
独の値を混合比に割り振ったときの値に近くなることが
確認できた。更に図１の曲線１１は、繊維状炭素と炭素
粉末の混合比を変えたときの平均細孔径との関係を示し
ている。図より繊維状炭素及び炭素粉末のみで構成した
負極の平均細孔系がそれぞれ０.１２，０.０７μｍであ
るのに対し、繊維状炭素の含有率が５０〜８５重量％の
範囲においては約０.３μｍと大きな値をとることが注
目に値する。以上述べたごとく異種形状炭素を組合せる
ことにより負極合剤層構造の物性値を任意に制御できる
ので前述の目的が達成されるものである。The pore volume, porosity and average pore diameter measured by a porosimeter for the mixed negative electrode obtained here are shown in FIGS. 11 and 1. Curves 9 and 10 in FIG.
The relationship between the pore volume and the porosity is shown. From FIG. 11, the pore volume of the negative electrode composed only of fibrous carbon and carbon powder,
Porosity is 0.34 cc / g, 57% and 0.12 cc / g
g, 40.8%, whereas the pore volume and porosity of the negative electrode mixed at an arbitrary ratio should be close to the values when fibrous carbon and carbon powder alone are assigned to the mixing ratio. Was confirmed. Further, a curve 11 in FIG. 1 shows the relationship with the average pore diameter when the mixing ratio of fibrous carbon and carbon powder is changed. From the figure, the average pore size of the negative electrode composed only of fibrous carbon and carbon powder is 0.12 and 0.07 μm, respectively, while in the range of fibrous carbon content of 50 to 85% by weight, It is worth noting that the value is as large as 0.3 μm. As described above, the physical properties of the negative electrode mixture layer structure can be arbitrarily controlled by combining differently shaped carbons, so that the above-mentioned object is achieved.
【００１７】ここで異種形状炭素とは、アスペクト比が
１０以上と１０以下のものに大別できる。最初にアスペ
クト比が１０以上の炭素材としては、アルカリ金属等を
ドープ、脱ドープ出来るものであればよく、例えば気相
成長炭素繊維、ピッチ系炭素繊維等があり、平均繊維径
０.０５〜０.５μｍ、平均繊維長さは５〜１００μｍ程
度のものが用いられる。又ずばり繊維状とは言えないが
隣片状或いは薄片状のものも使用でき平均粒径は１０μ
ｍ程度のものが好ましい。The differently shaped carbon can be roughly classified into those having an aspect ratio of 10 or more and 10 or less. First, the carbon material having an aspect ratio of 10 or more may be one that can be doped with and dedoped from an alkali metal or the like, and examples thereof include vapor grown carbon fiber and pitch-based carbon fiber, which have an average fiber diameter of 0.05 to 5. The average fiber length is 0.5 μm, and the average fiber length is about 5 to 100 μm. Moreover, although it cannot be said that it is a fibrous material, a flaky shape or a flaky shape can also be used, and the average particle size is 10 μm.
m is preferable.
【００１８】一方アスペクト比が１０以下の炭素材とし
ては、アルカリ金属等をドープ、脱ドープ出来るもので
あればよく、例えば天然黒鉛、人造黒鉛、熱分解炭素等
が使用でき、粉末の平均粒子径は１〜２０μｍ程度のも
のが使用される。On the other hand, the carbon material having an aspect ratio of 10 or less may be any material that can be doped with and dedoped from an alkali metal or the like. For example, natural graphite, artificial graphite, pyrolytic carbon, etc. can be used, and the average particle diameter of the powder. Is about 1 to 20 μm.
【００１９】次にアスペクト比の異なる炭素材を用いて
負極を形成する方法について説明する。アスペクト比の
大きい炭素材５０〜８５重量％に対しアスペクト比の小
さい炭素材を５０〜１５重量％になるようにした混合粉
に溶媒に溶解した。ＥＰＤＭ、ＰＶＤＦ等をバインダー
として加え、シート状（フィルム９より厚い）、フィル
ム状（金属箔なし）、金属箔上にフィルム状或いは発泡
金属に充填する等して電池形状に適応させる事が可能で
ある。ここでバインダーの添加量は炭素材に対し５〜１
５重量％、炭素材とバインダーとから成る合剤層厚みは
１０〜２００μｍの範囲が望しい。Next, a method of forming a negative electrode using carbon materials having different aspect ratios will be described. A carbon material having a small aspect ratio was dissolved in a solvent in a mixed powder in which a carbon material having a small aspect ratio was 50 to 15% by weight with respect to 50 to 85% by weight of a carbon material having a large aspect ratio. It is possible to adapt to the shape of the battery by adding EPDM, PVDF, etc. as a binder and filling it in sheet form (thicker than film 9), film form (without metal foil), film form on metal foil or foam metal. is there. Here, the addition amount of the binder is 5 to 1 with respect to the carbon material.
The thickness of the mixture layer composed of 5% by weight and the carbon material and the binder is preferably in the range of 10 to 200 μm.
【００２０】このようにして得られた負極は、通常用い
られる正極活物質、セパレータ及び電解液と組合せる事
により、角形、偏平形及び円筒形等の最適なリチウム二
次電池とすることができる。正極活物質としては、コバ
ルト、ニッケル、マンガンとリチウムの複合酸化物及び
コバルト、ニッケル、マンガンの一部を遷移金属で置換
した複合酸化物が用いられる。セパレータとしては、多
孔質ポリプロピレン、ポリエステルやポリオレフィン系
の多孔質膜が用いられる。又電解液としては、プロピレ
ンカーボネート（ＰＣ）、エチレンカーボネート（Ｅ
Ｃ）、ジメトキシエタン（ＤＭＥ）、ジメチルカーボネ
ート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、メ
チルエチルカーボネート（ＭＥＣ）等の２種類以上の混
合溶媒が用いられる。又電解質としては、ＬｉＰＦ6，
ＬｉＢＦ4，ＬｉＣｌＯ4等を用いる事ができ、上記溶媒
に溶解したものが用いられる。By combining the negative electrode thus obtained with a commonly used positive electrode active material, a separator and an electrolytic solution, an optimal lithium secondary battery having a prismatic shape, a flat shape or a cylindrical shape can be obtained. . As the positive electrode active material, cobalt, nickel, a composite oxide of manganese and lithium, or a composite oxide in which a part of cobalt, nickel, manganese is replaced with a transition metal is used. As the separator, a porous polypropylene, polyester or polyolefin type porous film is used. Further, as the electrolytic solution, propylene carbonate (PC), ethylene carbonate (E
Two or more kinds of mixed solvents such as C), dimethoxyethane (DME), dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC) are used. As the electrolyte, LiPF 6 ,
LiBF 4 , LiClO 4, etc. can be used, and those dissolved in the above solvent are used.
【００２１】すなわち、本発明は、正極、セパレータ、
負極及び電解液を備え、前記負極は集電体と、該集電体
上に設けられた合剤層とから成り、該合剤層は炭素繊維
と炭素粒子とから成ると共に繊維状炭素の含有率が５０
〜８５重量％であることを特徴とする非水二次電池であ
る。また他の発明は、前記発明において繊維状炭素はア
スペクト比が１０以上のものである。また他の発明は、
前記発明において、正極の活物質は、コバルト、ニッケ
ル、マンガンとリチウムの複合酸化物及びコバルト、ニ
ッケル、マンガンの一部を遷移金属で置換した複合酸化
物であり、負極は炭素繊維と炭素粒子の各炭素材へのリ
チウムのドープ、脱ドープに伴う不可逆容量に対し、両
炭素材の組合せに基づく不可逆容量を小さくした負極よ
りなるものである。That is, the present invention provides a positive electrode, a separator,
A negative electrode and an electrolytic solution are provided, and the negative electrode includes a current collector and a mixture layer provided on the current collector. The mixture layer includes carbon fibers and carbon particles and contains fibrous carbon. Rate is 50
It is a non-aqueous secondary battery characterized by being -85 weight%. In another invention, in the above invention, the fibrous carbon has an aspect ratio of 10 or more. Another invention is
In the above invention, the positive electrode active material is a composite oxide of cobalt, nickel, manganese and lithium and a composite oxide in which a part of cobalt, nickel, manganese is replaced with a transition metal, and the negative electrode is made of carbon fiber and carbon particles. It is composed of a negative electrode having a small irreversible capacity based on the combination of both carbon materials with respect to the irreversible capacity associated with the doping and dedoping of lithium into each carbon material.
【００２２】また他の発明は、正極、セパレータ負極及
び電解液から成り３２０ｗｈ／ｌ〜３８５ｗｈ／ｌのエ
ネルギー密度を有する非水二次電池である。Another aspect of the invention is a non-aqueous secondary battery comprising a positive electrode, a separator negative electrode and an electrolytic solution and having an energy density of 320 wh / l to 385 wh / l.
【００２３】[0023]
【作用】Ｌｉ二次電池用炭素負極の高容量化、長寿命化
及びＬｉ+ の不可逆容量の低減を達成するため、微細な
繊維状炭素と炭素粉末を特定の比（繊維状炭素の含有率
が５０〜８５重量％の範囲）で混合した炭素材を用いて
負極合剤層の炭素繊維の配向、細孔径、細孔容積、気孔
率及び厚み等を制御することにより、電子電導或いはイ
オン移動性の向上、電解液の拡散が容易、更には合剤層
強度の向上を図ることが出来た。その結果、前述の課題
を解決することが可能となった。このことは、正極と組
合せた電池においてエネルギー密度を飛躍的に向上させ
る効果をもつ。[Function] In order to achieve high capacity, long life and reduction of irreversible capacity of Li + of carbon negative electrode for Li secondary battery, fine fibrous carbon and carbon powder are mixed in a specific ratio (content ratio of fibrous carbon). Of 50 to 85% by weight) is used to control the orientation, pore diameter, pore volume, porosity, thickness, etc. of the carbon fibers of the negative electrode mixture layer to control electron conduction or ion transfer. It was possible to improve the properties, facilitate the diffusion of the electrolytic solution, and further improve the strength of the mixture layer. As a result, it has become possible to solve the above-mentioned problems. This has the effect of dramatically improving the energy density of the battery combined with the positive electrode.
【００２４】[0024]
（実施例１）気相成長炭素繊維（平均繊維径：０.２μ
ｍ、平均繊維長：２０μｍ）と高純度黒鉛粉末（平均粒
径：３μｍ）の双方を５０重量％になるように混合し、
これにＤＥＢに溶解したＥＰＤＭを用い炭素材に対しＥ
ＰＤＭが６重量％になるように添加し十分に混練した。
このペーストを厚さ２５μｍの銅箔に塗布し風乾後、空
気中８０℃で３ｈ乾燥した。その後、０.５ton／cm2の
圧力で成型し更に真空中１５０℃で２ｈ熱処理を行って
負極を作成した。この負極と対極としてＬｉ金属及びポ
リプロピレン製セパレーターを組合せ、電解液として１
ＭＬｉＰＦ6／ＥＣ−ＤＭＥ、参照極としてＬｉ金属を
用い、カーボン１ｇ当りの充放電電流値８０ｍＡ／ｇ・
Ｃ、電位幅１０ｍＶ〜１．０Ｖで単極試験を行った。(Example 1) Vapor grown carbon fiber (average fiber diameter: 0.2μ)
m, average fiber length: 20 μm) and high-purity graphite powder (average particle size: 3 μm) were mixed so as to be 50% by weight,
Using EPDM dissolved in DEB for this, E for carbon material
The PDM was added so as to be 6% by weight and sufficiently kneaded.
This paste was applied to a copper foil having a thickness of 25 μm, air-dried, and then dried in air at 80 ° C. for 3 hours. Then, the negative electrode was formed by molding at a pressure of 0.5 ton / cm 2 and further heat treatment at 150 ° C. for 2 hours in vacuum. This negative electrode is combined with a Li metal and polypropylene separator as a counter electrode, and as an electrolytic solution, 1
MLiPF 6 / EC-DME, using Li metal as a reference electrode, the charge / discharge current value per 1 g of carbon is 80 mA / g.
A unipolar test was performed at C and a potential width of 10 mV to 1.0 V.
【００２５】（実施例２）実施例１と同じ気相長成炭素
と高純度黒鉛粉末を７０：３０重量％で混合した炭素材
を用いて実施例１と同様負極を作成し単極評価を行っ
た。Example 2 A negative electrode was prepared in the same manner as in Example 1 by using a carbon material obtained by mixing the same vapor-grown carbon and high-purity graphite powder as in Example 1 at 70: 30% by weight, and single-pole evaluation was performed. went.
【００２６】（実施例３）実施例１と同じ気相成長炭素
と高純度黒鉛粉末を８５：１５重量％で混合した炭素材
を用いて実施例１と同様負極を作成し単極評価を行っ
た。Example 3 A negative electrode was prepared in the same manner as in Example 1 using a carbon material in which the same vapor-grown carbon and high-purity graphite powder as in Example 1 were mixed at 85:15 wt%, and unipolar evaluation was performed. It was
【００２７】（比較例１）実施例１で用いた気相成長炭
素繊維のみを用いて実施例１と同様負極を作成し単極評
価を行った。Comparative Example 1 A negative electrode was prepared in the same manner as in Example 1 by using only the vapor-grown carbon fibers used in Example 1 and single pole evaluation was performed.
【００２８】（比較例２）実施例１で用いた高純度黒鉛
粉末のみを用いて実施例１と同様、負極を作成し単極評
価を行った。Comparative Example 2 A negative electrode was prepared in the same manner as in Example 1 by using only the high-purity graphite powder used in Example 1, and single-pole evaluation was performed.
【００２９】実施例１〜３と比較例１〜２での負極の単
極試験で得られた結果から、それぞれの不可逆容量率を
求め図２に示した。図の曲線１２にみられるごとく気相
成長炭素繊維、高純度黒鉛粉末のみの場合の不可逆容量
率はそれぞれ２５％と３８％であるのに対し、本発明
（実施例１〜３）より成る負極の不可逆容量は約１８％
と本発明の効果が認められた。The irreversible capacity ratios of the negative electrodes in Examples 1 to 3 and Comparative Examples 1 and 2 were obtained from the results obtained in the unipolar test, and the results are shown in FIG. As can be seen from the curve 12 in the figure, the irreversible capacity ratios of vapor-grown carbon fiber and high-purity graphite powder alone are 25% and 38%, respectively, whereas the negative electrodes according to the present invention (Examples 1 to 3) are used. Irreversible capacity is about 18%
Thus, the effect of the present invention was confirmed.
【００３０】（実施例４）気相成長炭素繊維（実施例１
と同じ）と炭素粉末（人造黒鉛、平均粒径：２０μｍ）
を５０：５０重量％で混合した炭素材を用いた作成した
負極で実施例１と同様の単極評価を行った。(Example 4) Vapor grown carbon fiber (Example 1)
Same) and carbon powder (artificial graphite, average particle size: 20 μm)
The same single electrode evaluation as in Example 1 was performed on the prepared negative electrode using the carbon material mixed with 50: 50% by weight.
【００３１】（比較例３）実施例４で用いた炭素粉末の
みで負極を作成し、実施例１と同様の単極評価を行っ
た。(Comparative Example 3) A negative electrode was prepared using only the carbon powder used in Example 4, and the same unipolar evaluation as in Example 1 was performed.
【００３２】実施例４と比較例３での負極の単極試験結
果からそれぞれの不可逆容量率は、前者で１９％、後者
で３２％であった。From the results of the unipolar test of the negative electrodes in Example 4 and Comparative Example 3, the irreversible capacity ratios were 19% for the former and 32% for the latter.
【００３３】（実施例５）隣片状天然黒鉛（平均粒径：
２.５μｍ）と高純度黒鉛粉末（実施例１）を８５：１
５重量％になるように混合した炭素材を用いて実施例１
と同様負極を作成し単極評価を行った。Example 5 Adjacent flaky graphite (average particle size:
2.5 μm) and high-purity graphite powder (Example 1) 85: 1
Example 1 using a carbon material mixed so as to be 5% by weight
A negative electrode was prepared in the same manner as in 1. and a single pole evaluation was performed.
【００３４】（比較例４）実施例５で用いた隣片状天然
黒鉛のみで負極を作成し実施例１と同様の単極評価を行
った。(Comparative Example 4) A negative electrode was prepared using only the flaky natural graphite used in Example 5, and the same unipolar evaluation as in Example 1 was performed.
【００３５】実施例５と比較例４での負極の単極試験結
果におけるそれぞれの不可逆容量率は、前者で１８％、
後者で２６％であった。The irreversible capacity ratios of the negative electrodes in Example 5 and Comparative Example 4 in the unipolar test results were 18% in the former case,
The latter was 26%.
【００３６】（実施例６）実施例１のＥＰＤＭバインダ
ーの代りにＰＶＤＦ／Ｎ−メチルピロリドン溶液を用い
てＰＶＤＦが炭素材に対して６重量％になるように添加
した事、最終熱処理条件を真空中１２０℃で２ｈとした
点以外は、実施例１と同様の負極を作成し単極評価を行
った。その結果、不可逆容量の値は、ＥＰＤＭバインダ
ーを用いたとほぼ同じであった。Example 6 A PVDF / N-methylpyrrolidone solution was used instead of the EPDM binder of Example 1, and PVDF was added to the carbon material in an amount of 6% by weight, and the final heat treatment condition was vacuum. A negative electrode similar to that in Example 1 was prepared except that the temperature was set to 120 ° C. for 2 hours, and the single electrode was evaluated. As a result, the value of the irreversible capacity was almost the same as that using the EPDM binder.
【００３７】（実施例７）実施例２及び実施例５の負極
を用いて実施例１と同じ評価法で寿命試験を行った。そ
の結果を図３の直線１３に示す。図３において３００サ
イクルの寿命試験においても、初期放電容量から約１０
％の容量低下にとどまる良好な特性を示していることを
確認している。ちなみに実施例１，３，４，５及び６の
負極もほぼ同等のサイクル特性を示した。(Example 7) Using the negative electrodes of Examples 2 and 5, a life test was conducted by the same evaluation method as in Example 1. The result is shown by the straight line 13 in FIG. Even in the life test of 300 cycles in FIG. 3, about 10 from the initial discharge capacity.
It has been confirmed that it exhibits good characteristics of only capacity reduction of%. By the way, the negative electrodes of Examples 1, 3, 4, 5 and 6 also showed almost the same cycle characteristics.
【００３８】（比較例５）比較例２の負極を用いて実施
例７と同様の寿命試験を行った。その結果を図３に示
す。図３の曲線１４にみられるように初期放電容量から
１０サイクル目まで急激な容量低下があり、その後はゆ
るやかな容量低下曲線となる。１０サイクルから３００
サイクルにおける容量低下は、およそ３４％であった。Comparative Example 5 Using the negative electrode of Comparative Example 2, the same life test as in Example 7 was conducted. The result is shown in FIG. As can be seen from the curve 14 in FIG. 3, there is a rapid capacity decrease from the initial discharge capacity to the 10th cycle, and thereafter, a gentle capacity decrease curve is formed. 10 cycles to 300
The capacity loss on cycle was approximately 34%.
【００３９】（実施例８）実施例２と同じ負極及び電解
液として１ＭＬｉＰＦ6／ＥＣ−ＤＥＣを用い、実施例
１と同様の単極試験を行った。このときの不可逆容量率
は約２０％であった。Example 8 Using the same negative electrode as in Example 2 and 1 M LiPF 6 / EC-DEC as the electrolytic solution, the same unipolar test as in Example 1 was conducted. The irreversible capacity ratio at this time was about 20%.
【００４０】（実施例９）実施例２と同じ負極、電解液
として１ＭＬｉＰＦ6／ＥＣ−ＤＭＣ及びポリエステル
製セパレータを用い実施例１と同様の単極試験を行っ
た。このときの不可逆容量率は約１３％であった。Example 9 The same unipolar test as in Example 1 was conducted using the same negative electrode as in Example 2, 1 M LiPF 6 / EC-DMC as the electrolyte and a polyester separator. The irreversible capacity ratio at this time was about 13%.
【００４１】（実施例１０）実施例２と同じ負極、電解
液として１ＭＬｉＰＦ6／ＥＣ−ＭＥＣ及びポリエステ
ル製セパレータを用い、実施例１と同様の単極試験を行
った。このときの不可逆容量率は、約１３％であった。Example 10 Using the same negative electrode as in Example 2, 1 M LiPF 6 / EC-MEC and a polyester separator as the electrolytic solution, the same unipolar test as in Example 1 was conducted. The irreversible capacity ratio at this time was about 13%.
【００４２】（実施例１１）厚さ２０μｍのアルミ箔に
ＬｉＣｏＯ2活物質を人造黒鉛とＰＶＤＦを重量比で８
７：９：４とした合剤を片面９０μｍとなるように両面
塗布し、乾燥・圧延した正極、厚さ３３μｍの銅箔に実
施例２と同じ組成物を片面５８μｍとなるように両面塗
布し、乾燥・圧延した負極及び厚さ２５μｍのポリエス
テル製多孔質膜セパレータを図１２にモデル的に示した
ように巻回して外寸法直径１４ｍｍ×長さ４７ｍｍの電
池缶に収納し、電解液として１ＭＬｉＰＦ6／ＥＣ−Ｍ
ＥＣを用いて、その特性を評価した。図１２で、１５は
正極、１６は正極端子、１７は負極、１８は負極端子、
１９はセパレータを示す。(Embodiment 11) An aluminum foil having a thickness of 20 μm, a LiCoO 2 active material, artificial graphite and PVDF in a weight ratio of 8 were used.
The mixture of 7: 9: 4 was applied on both sides so as to have a thickness of 90 μm on one side, and the dried and rolled positive electrode and a copper foil with a thickness of 33 μm were coated with the same composition as in Example 2 on both sides so as to have a thickness of 58 μm on one side. The dried / rolled negative electrode and the 25 μm-thick polyester porous membrane separator were wound as shown in a model in FIG. 12 and housed in a battery can having an outer diameter of 14 mm and a length of 47 mm. 6 / EC-M
Its properties were evaluated using EC. In FIG. 12, 15 is a positive electrode, 16 is a positive electrode terminal, 17 is a negative electrode, 18 is a negative electrode terminal,
Reference numeral 19 represents a separator.
【００４３】試験条件として、充放電電流７５ｍＡ（８
時間率）、充電終止電圧４.２Ｖ、放電終止電圧２.５Ｖ
として行った。その結果、３２０ｗｈ／ｌのエネルギー
密度が得られ、１００サイクルまで安定した性能を示し
た。As a test condition, a charge / discharge current of 75 mA (8
Time rate), end-of-charge voltage 4.2V, end-of-discharge voltage 2.5V
Went as. As a result, an energy density of 320 wh / l was obtained and stable performance was exhibited up to 100 cycles.
【００４４】（実施例１２）厚さ２０μｍのアルミ箔に
ＬｉＮｉＯ2活物質と人造黒鉛とＰＶＤＦを重量比で８
７：９：４とした合剤を片面９０μｍとなるように両面
塗布し、乾燥・圧延した正極、厚さ３３μｍの銅箔に実
施例２と同じ組成物を片面７７μｍになるように両面塗
布し、乾燥・圧延した負極を用いて実施例１１と同様に
電池を構成し、充放電電流９０ｍＡ（８時間中）で試験
を行った。その結果３８５ｗｈ／ｌのエネルギー密度が
得られ、８０サイクルまで安定した性能を示した。(Embodiment 12) LiNiO 2 active material, artificial graphite and PVDF were mixed in a weight ratio of 8 on an aluminum foil having a thickness of 20 μm.
The mixture of 7: 9: 4 was applied on both sides so as to have a thickness of 90 μm on one side, and the dried and rolled positive electrode and a copper foil with a thickness of 33 μm were applied with the same composition as in Example 2 on both sides so as to have a thickness of 77 μm on one side. A battery was constructed in the same manner as in Example 11 using the dried and rolled negative electrode, and the test was performed at a charge / discharge current of 90 mA (during 8 hours). As a result, an energy density of 385 wh / l was obtained, and stable performance was exhibited up to 80 cycles.
【００４５】[0045]
【発明の効果】本発明によれば、負極構造の細孔径、気
孔率及び細孔容積等を自由に制御することが可能とな
り、電子電導性、イオンの移動度、電解液の拡散性及び
合剤層の機械的強度が向上する結果、Ｌｉ+ の不可逆容
量の低下、負極容量の向上及び長寿命化が達成できる結
果、電池のエネルギー密度を飛躍的に向上させる効果が
ある。According to the present invention, it becomes possible to freely control the pore diameter, porosity, pore volume and the like of the negative electrode structure, and the electron conductivity, the ion mobility, the diffusivity of the electrolyte and As a result of improving the mechanical strength of the agent layer, the irreversible capacity of Li + can be reduced, the capacity of the negative electrode can be improved, and the service life can be prolonged. As a result, the energy density of the battery can be dramatically improved.
【図１】炭素繊維と炭素粉末の混合比をかえた合剤量の
平均細孔径を示す図である。FIG. 1 is a diagram showing the average pore diameter of the mixture amount with the mixing ratio of carbon fiber and carbon powder changed.
【図２】炭素繊維と炭素粉末の混合比を変化させた負極
の不可逆容量を示す図である。FIG. 2 is a diagram showing an irreversible capacity of a negative electrode in which the mixing ratio of carbon fiber and carbon powder is changed.
【図３】本発明と従来負極のサイクル特性を示す図であ
る。FIG. 3 is a diagram showing cycle characteristics of the present invention and a conventional negative electrode.
【図４】高純度黒鉛及び気相成長炭素繊維負極のサイル
特性を示す図である。FIG. 4 is a diagram showing the sile characteristics of high-purity graphite and a vapor-grown carbon fiber negative electrode.
【図５】負極成型圧力とかさ密度の関係を示す図であ
る。FIG. 5 is a diagram showing the relationship between negative electrode molding pressure and bulk density.
【図６】負極合剤層厚みと放電容量の関係を示す図であ
る。FIG. 6 is a diagram showing the relationship between the negative electrode mixture layer thickness and the discharge capacity.
【図７】負極合剤層かさ密度と放電容量の関係を示す図
である。FIG. 7 is a diagram showing the relationship between the bulk density of the negative electrode mixture layer and the discharge capacity.
【図８】Ｌｉ二次電池用負極の製造工程を示す図であ
る。FIG. 8 is a diagram showing a manufacturing process of a negative electrode for a Li secondary battery.
【図９】炭素繊維長の異なる負極の放電容量を示す図で
ある。FIG. 9 is a diagram showing discharge capacities of negative electrodes having different carbon fiber lengths.
【図１０】炭素繊維と炭素粉末の混合比を変えたときの
かさ密度を示す図である。FIG. 10 is a view showing the bulk density when the mixing ratio of carbon fiber and carbon powder is changed.
【図１１】炭素繊維と炭素粉末の混合比かえた合剤層の
細孔容積と気孔率を示す図である。FIG. 11 is a diagram showing the pore volume and the porosity of the mixture layer in which the mixing ratio of carbon fiber and carbon powder is changed.
【図１２】円筒形電池の構成図である。FIG. 12 is a configuration diagram of a cylindrical battery.
１ 高純度黒鉛粒子 ２ 気相成長炭素繊維 ８ 気相成長炭素繊維と高純度黒鉛混合粉のかさ密度 ９ 各種炭素負極合剤層の細孔容積 １０ 気孔率 １１ 各種炭素負極合剤層の平均細孔径 １２ 炭素繊維と高純度黒鉛混合比の異なる負極の不可
逆容量 １５ 正極 １６ 正極端子 １７ 負極 １８ 負極端子 １９ セパレータ1 high-purity graphite particles 2 vapor-grown carbon fiber 8 bulk density of vapor-grown carbon fiber and high-purity graphite mixed powder 9 pore volume of various carbon negative electrode mixture layers 10 porosity 11 average fineness of various carbon negative electrode mixture layers Pore size 12 Irreversible capacity of negative electrode having different mixing ratio of carbon fiber and high-purity graphite 15 Positive electrode 16 Positive electrode terminal 17 Negative electrode 18 Negative electrode terminal 19 Separator
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山形 武夫 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 堀場 達雄 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 村中 廉 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Yamagata 7-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Tatsuo Horiba 7-chome, Omika-cho, Hitachi, Ibaraki No. 1 in Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Ren Muranaka 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd.
Claims (4)
え、前記負極は集電体と、該集電体上に設けられた合剤
層とから成り、該合剤層は炭素繊維と炭素粒子とから成
ると共に繊維状炭素の含有率が５０〜８５重量％である
ことを特徴とする非水二次電池。1. A positive electrode, a separator, a negative electrode and an electrolytic solution, the negative electrode comprising a current collector and a mixture layer provided on the current collector, the mixture layer comprising carbon fibers and carbon particles. And a fibrous carbon content of 50 to 85% by weight.
クト比が１０以上であることを特徴とする非水二次電
池。2. The non-aqueous secondary battery according to claim 1, wherein the fibrous carbon has an aspect ratio of 10 or more.
は、コバルト、ニッケル、マンガンとリチウムの複合酸
化物及びコバルト、ニッケル、マンガンの一部を遷移金
属で置換した複合酸化物であり、負極は炭素繊維と炭素
粒子の各炭素材へのリチウムのドープ、脱ドープに伴う
不可逆容量に対し、両炭素材の組合せに基づく不可逆容
量を小さくした負極であることを特徴とする非水二次電
池。3. The active material of the positive electrode according to claim 1, wherein the active material of the positive electrode is a composite oxide of cobalt, nickel, manganese and lithium, or a composite oxide in which a part of cobalt, nickel, manganese is replaced with a transition metal, The negative electrode is a negative electrode characterized by reducing the irreversible capacity based on the combination of both carbon materials with respect to the irreversible capacity associated with the doping and dedoping of lithium into each carbon material of carbon fibers and carbon particles. battery.
り３２０ｗｈ／ｌ〜３８５ｗｈ／ｌのエネルギー密度を
有する非水二次電池。4. A non-aqueous secondary battery comprising a positive electrode, a separator negative electrode and an electrolytic solution and having an energy density of 320 wh / l to 385 wh / l.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17608895A JP3289098B2 (en) | 1995-07-12 | 1995-07-12 | Non-aqueous secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17608895A JP3289098B2 (en) | 1995-07-12 | 1995-07-12 | Non-aqueous secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0927315A true JPH0927315A (en) | 1997-01-28 |
| JP3289098B2 JP3289098B2 (en) | 2002-06-04 |
Family
ID=16007507
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17608895A Expired - Fee Related JP3289098B2 (en) | 1995-07-12 | 1995-07-12 | Non-aqueous secondary battery |
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| Country | Link |
|---|---|
| JP (1) | JP3289098B2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0856898A3 (en) * | 1997-02-04 | 1999-06-30 | Mitsubishi Denki Kabushiki Kaisha | Electrode for lithium ion secondary battery and lithium ion secondary battery using the same |
| JP2001015170A (en) * | 1999-06-29 | 2001-01-19 | Sony Corp | Nonaqueous electrolyte battery |
| US6858349B1 (en) | 2000-09-07 | 2005-02-22 | The Gillette Company | Battery cathode |
| WO2007004728A1 (en) * | 2005-07-04 | 2007-01-11 | Showa Denko K.K. | Method for producing anode for lithium secondary battery and anode composition, and lithium secondary battery |
| JP2008077993A (en) * | 2006-09-21 | 2008-04-03 | Mitsubishi Chemicals Corp | Electrode and non-aqueous secondary battery |
| JP2009059713A (en) * | 2008-11-11 | 2009-03-19 | Mitsubishi Materials Corp | Negative electrode material, negative electrode using the same, and lithium ion battery and lithium polymer battery using the negative electrode |
| JP2009146581A (en) * | 2007-12-11 | 2009-07-02 | Osaka Gas Chem Kk | Sheet-shaped negative electrode for lithium ion secondary battery, and manufacturing method thereof |
| US7611804B2 (en) | 2004-03-31 | 2009-11-03 | Hitachi Maxell, Ltd. | Nonaqueous secondary battery and electronic equipment using the same |
| JP2013222550A (en) * | 2012-04-13 | 2013-10-28 | Sumitomo Bakelite Co Ltd | Negative electrode material, negative electrode and lithium ion secondary battery |
| US20150065634A1 (en) * | 2013-08-29 | 2015-03-05 | Arkema France | Battery gasket based on a polyamide composition |
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1995
- 1995-07-12 JP JP17608895A patent/JP3289098B2/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0856898A3 (en) * | 1997-02-04 | 1999-06-30 | Mitsubishi Denki Kabushiki Kaisha | Electrode for lithium ion secondary battery and lithium ion secondary battery using the same |
| JP2001015170A (en) * | 1999-06-29 | 2001-01-19 | Sony Corp | Nonaqueous electrolyte battery |
| US6858349B1 (en) | 2000-09-07 | 2005-02-22 | The Gillette Company | Battery cathode |
| US7611804B2 (en) | 2004-03-31 | 2009-11-03 | Hitachi Maxell, Ltd. | Nonaqueous secondary battery and electronic equipment using the same |
| US8685362B2 (en) | 2005-07-04 | 2014-04-01 | Showa Denko K.K. | Method for producing anode for lithium secondary battery and anode composition, and lithium secondary battery |
| WO2007004728A1 (en) * | 2005-07-04 | 2007-01-11 | Showa Denko K.K. | Method for producing anode for lithium secondary battery and anode composition, and lithium secondary battery |
| US9276257B2 (en) | 2005-07-04 | 2016-03-01 | Showa Denko K.K. | Method for producing anode for lithium secondary battery and anode composition, and lithium secondary battery |
| US8003257B2 (en) | 2005-07-04 | 2011-08-23 | Showa Denko K.K. | Method for producing anode for lithium secondary battery and anode composition, and lithium secondary battery |
| JP2008077993A (en) * | 2006-09-21 | 2008-04-03 | Mitsubishi Chemicals Corp | Electrode and non-aqueous secondary battery |
| JP2009146581A (en) * | 2007-12-11 | 2009-07-02 | Osaka Gas Chem Kk | Sheet-shaped negative electrode for lithium ion secondary battery, and manufacturing method thereof |
| JP2009059713A (en) * | 2008-11-11 | 2009-03-19 | Mitsubishi Materials Corp | Negative electrode material, negative electrode using the same, and lithium ion battery and lithium polymer battery using the negative electrode |
| JP2013222550A (en) * | 2012-04-13 | 2013-10-28 | Sumitomo Bakelite Co Ltd | Negative electrode material, negative electrode and lithium ion secondary battery |
| US20150065634A1 (en) * | 2013-08-29 | 2015-03-05 | Arkema France | Battery gasket based on a polyamide composition |
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|---|---|
| JP3289098B2 (en) | 2002-06-04 |
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