JP2003173781A - Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them - Google Patents

Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them

Info

Publication number
JP2003173781A
JP2003173781A JP2002109835A JP2002109835A JP2003173781A JP 2003173781 A JP2003173781 A JP 2003173781A JP 2002109835 A JP2002109835 A JP 2002109835A JP 2002109835 A JP2002109835 A JP 2002109835A JP 2003173781 A JP2003173781 A JP 2003173781A
Authority
JP
Japan
Prior art keywords
polymer binder
secondary battery
electrode
active material
adhesive layer
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.)
Pending
Application number
JP2002109835A
Other languages
Japanese (ja)
Inventor
Yusuke Watarai
祐介 渡会
Akio Mizuguchi
暁夫 水口
Akihiro Higami
晃裕 樋上
Shuhin Cho
守斌 張
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Corp filed Critical Mitsubishi Materials Corp
Priority to JP2002109835A priority Critical patent/JP2003173781A/en
Publication of JP2003173781A publication Critical patent/JP2003173781A/en
Pending legal-status Critical Current

Links

Classifications

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

Abstract

<P>PROBLEM TO BE SOLVED: To improve adhesiveness and conductivity between a collector and an active material layer and improve cycle capacity maintenance characteristics. <P>SOLUTION: With the electrode for a secondary battery, active material layers 13, 17 are fitted on one side or both sides of collectors 12, 16 with adhesive layers 19, 21 having a polymer binder interposed in between. A part of the polymer binder exists in the adhesive layers 19, 21 in a state of particles, and that particulate polymer binder has an average volume particle diameter of 1 to 100 μm. A main ingredient of the polymer binder is either fluorocarbon resin or a compound graft polymerized on polyvinylidene fluoride with either acrylic or methacrylic acid as a monomer. An area density of the particulate polymer binder in the adhesive layers 19, 21 at cross section parallel with the surface of the adhesive layers 19, 21 is 1 to 100 pieces per cm<SP>2</SP>. With the use of the electrodes 11, 14 for the secondary battery is obtained a secondary battery. <P>COPYRIGHT: (C)2003,JPO

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、二次電池の集電体
と活物質層の間に設けられる密着層に含まれるポリマー
結着剤、集電体の片面に密着層を介して活物質層が設け
られた二次電池用電極及びこれらを用いた二次電池に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer binder contained in an adhesion layer provided between a current collector and an active material layer of a secondary battery, and an active material on one side of the current collector via the adhesion layer. The present invention relates to a secondary battery electrode provided with a layer and a secondary battery using these electrodes.

【０００２】[0002]

【従来の技術】近年のビデオカメラやノート型パソコン
等のポータブル機器の普及により薄型の電池に対する需
要が高まっている。この薄型の電池として正極電極と負
極電極を積層して形成されたリチウムイオンポリマー二
次電池が知られている。この正極電極は、シート状の正
極集電体の表面に活物質層を形成することにより作ら
れ、負極電極は、シート状の負極集電体の表面に活物質
層を形成することにより作られる。正極電極の活物質層
と負極電極の活物質層の間には電解質層が介装される。
この電池では、それぞれの活物質における電位差を電流
として取出すための正極端子及び負極端子が正極集電体
及び負極集電体に設けられ、このように積層されたもの
をパッケージで密閉することによりリチウムイオンポリ
マー二次電池が形成されている。このリチウムイオンポ
リマー二次電池ではパッケージから引出された正極端子
及び負極端子を電池の端子として使用することにより所
望の電気が得られるようになっている。2. Description of the Related Art With the recent widespread use of portable devices such as video cameras and notebook computers, the demand for thin batteries is increasing. A lithium ion polymer secondary battery formed by stacking a positive electrode and a negative electrode is known as this thin battery. The positive electrode is formed by forming an active material layer on the surface of a sheet-shaped positive electrode current collector, and the negative electrode is formed by forming an active material layer on the surface of a sheet-shaped negative electrode current collector. . An electrolyte layer is interposed between the active material layer of the positive electrode and the active material layer of the negative electrode.
In this battery, a positive electrode terminal and a negative electrode terminal for taking out a potential difference in each active material as a current are provided in a positive electrode current collector and a negative electrode current collector, and by stacking such a laminated product in a package, lithium An ionic polymer secondary battery is formed. In this lithium ion polymer secondary battery, desired electricity can be obtained by using the positive electrode terminal and the negative electrode terminal drawn out from the package as the terminals of the battery.

【０００３】このような構造を有するリチウムイオンポ
リマー二次電池は電池電圧が高く、エネルギー密度も大
きいため、非常に注目されている。このリチウムイオン
ポリマー二次電池の放電容量を更に増大させるためには
シート状の正極又は負極の面積を拡大させる必要があ
る。この正極又は負極の面積を単純に拡大するだけでは
広い面積のために、その取扱いが困難になる不具合があ
る。この点を解消するために、拡大したシート状の正極
又は負極を所望の大きさに折畳んだり、捲回したりする
ことも考えられる。しかし、シート状の正極又は負極を
積層した状態で折畳みや捲回を行うと、折目部分におけ
る正極又は負極に撓みが生じ、その部分におけるシート
が電解質層から剥離して電極と電解質界面の有効表面積
が減少して放電容量が減少するとともに、電池内部に抵
抗を生じさせて放電容量のサイクル特性を悪化させる不
具合がある。また同様に、折目部分に撓みが生じること
により正極又は負極をそれぞれ形成している活物質層が
集電体より剥離する問題もあった。更に、この電池は充
電及び放電過程において、正極及び負極活物質中へのリ
チウムイオンの吸蔵、放出によって正極及び負極活物質
層の膨張、収縮が起こり、これにより発生する応力によ
り、活物質層が集電体より剥離する問題もあった。The lithium-ion polymer secondary battery having such a structure has received a great deal of attention because it has a high battery voltage and a large energy density. In order to further increase the discharge capacity of this lithium ion polymer secondary battery, it is necessary to increase the area of the sheet-shaped positive electrode or negative electrode. If the area of the positive electrode or the negative electrode is simply enlarged, it will be difficult to handle because of the large area. In order to solve this point, it is conceivable to fold or wind the expanded sheet-shaped positive electrode or negative electrode into a desired size. However, when the sheet-shaped positive electrode or negative electrode is folded or wound in a laminated state, the positive electrode or negative electrode is bent at the fold portion, and the sheet at that portion peels from the electrolyte layer, and the electrode-electrolyte interface becomes effective. There is a problem that the surface area is reduced and the discharge capacity is reduced, and resistance is generated inside the battery to deteriorate the cycle characteristics of the discharge capacity. In addition, similarly, there is a problem that the active material layers forming the positive electrode and the negative electrode are separated from the current collector due to the bending at the folds. Further, in this battery, during charging and discharging processes, the positive and negative electrode active material layers expand and contract due to occlusion and release of lithium ions in the positive and negative electrode active materials, and the active material layer is expanded due to the stress generated thereby. There was also a problem of peeling from the current collector.

【０００４】これらの点を解消するために、集電体と活
物質層との間に、ドット状、ストライプ状又は格子状の
いずれかの塗工パターンを有する接着層が設けられた電
池用電極が開示されている（特開平１１−７３９４７
号）。この電池用電極では、上記接着剤層を形成するた
めの塗料がスプレーにより或いは印刷により形成され
る。また集電体の活物質層保持面の面積に対する接着層
の塗工面積の割合が３０〜８０％である。このように構
成された電池用電極では、集電体と活物質層との間に所
定の塗工パターンを有する接着層が形成されているた
め、集電体と活物質層との間の電子の授受を妨げること
なく、両者の密着性を改善でき、サイクル特性を向上で
きる。具体的には、所定の塗工パターンを有する接着層
により集電体と活物質層との密着性が確保され、未塗工
部において集電体と活物質層との間の電子の授受が円滑
に行われ、電気抵抗を低く抑えることができる。In order to solve these problems, a battery electrode in which an adhesive layer having a dot-shaped, stripe-shaped, or grid-shaped coating pattern is provided between the current collector and the active material layer. Is disclosed (Japanese Patent Laid-Open No. 11-73947).
issue). In this battery electrode, the paint for forming the adhesive layer is formed by spraying or printing. The ratio of the coating area of the adhesive layer to the area of the active material layer holding surface of the current collector is 30 to 80%. In the battery electrode thus configured, since the adhesive layer having a predetermined coating pattern is formed between the current collector and the active material layer, the electron between the current collector and the active material layer is formed. It is possible to improve the adhesion between the two and to improve the cycle characteristics without hindering the transfer of. Specifically, the adhesion between the current collector and the active material layer is ensured by the adhesive layer having a predetermined coating pattern, and the transfer of electrons between the current collector and the active material layer in the uncoated part is performed. It is carried out smoothly, and the electric resistance can be kept low.

【０００５】また、別の技術として、電池電極を構成す
る結着剤を電極材中に均一に分散させた電極が提案され
ている（特開平７−６７５２号）。この電極は、結着剤
が分散した電極材を集電体上に形成し、この電極材を乾
燥して加圧成形した後に熱処理することにより製造され
る。このように構成された電極を用いることにより、放
電容量特性、特にサイクル特性に優れた高性能二次電池
を作製できる。As another technique, an electrode in which a binder constituting a battery electrode is uniformly dispersed in an electrode material has been proposed (JP-A-7-6752). This electrode is manufactured by forming an electrode material in which a binder is dispersed on a current collector, drying the electrode material, press-molding it, and then heat-treating it. By using the electrode configured as described above, a high performance secondary battery having excellent discharge capacity characteristics, particularly cycle characteristics, can be manufactured.

【０００６】[0006]

【発明が解決しようとする課題】しかし、上記特開平１
１−７３９４７号に記載された従来の電池用電極では、
接着層をドット状、ストライプ状又は格子状のいずれか
の塗工パターンに形成する必要があり、その接着層の形
成が非常に困難である問題点がある。また、集電体と活
物質層との間の電子の授受が行われる未塗工部における
面積が比較的大きい場合にはその部分における密着性が
十分に確保されずに剥離するという未だ解決すべき課題
が残存していた。また、上記特開平７−６７５２号に記
載された従来の電極では、結着剤としてのポリマー或い
は結着効果をもたらすポリマー電解質を完全に溶媒に溶
かし、他の材料カーボン、活物質などと均一に混合し
て、塗工用スラリーを調製するので、作成した活物質層
と集電体との密着強度が十分でなく、電池の充放電サイ
クル特性が低下するという未だ解決すべき課題が残存し
ていた。その原因は、塗工用スラリーに添加しているカ
ーボンなどの粉末材料が集電体と活物質層の界面に大量
に存在したためと考えられる。本発明の目的は、集電体
と活物質層との密着性及び導電性に優れ、かつサイクル
容量維持特性を向上し得るポリマー結着剤並びに二次電
池用電極及びこれらを用いた二次電池を提供することに
ある。However, the above-mentioned Japanese Unexamined Patent Application Publication No.
In the conventional battery electrode described in 1-73947,
It is necessary to form the adhesive layer in a dot-shaped, stripe-shaped, or lattice-shaped coating pattern, and there is a problem that it is very difficult to form the adhesive layer. Further, when the area in the uncoated portion where electrons are transferred between the current collector and the active material layer is relatively large, the adhesion in that portion is not sufficiently secured and peeling is still a problem. There were remaining issues to be solved. Further, in the conventional electrode described in JP-A-7-6752, a polymer as a binder or a polymer electrolyte that brings about a binding effect is completely dissolved in a solvent and uniformly mixed with other materials such as carbon and active material. Since the mixture is mixed to prepare a coating slurry, the adhesion strength between the active material layer and the current collector thus created is not sufficient, and the problem to be solved that the charge / discharge cycle characteristics of the battery deteriorates still remains. It was It is considered that the cause is that a large amount of powder material such as carbon added to the coating slurry was present at the interface between the current collector and the active material layer. An object of the present invention is to provide a polymer binder having excellent adhesion and conductivity between a current collector and an active material layer, and capable of improving cycle capacity retention characteristics, a secondary battery electrode, and a secondary battery using the same. To provide.

【０００７】[0007]

【課題を解決するための手段】請求項１に係る発明は、
図１に示すように、導電助剤とポリマー結着剤及び溶媒
を含む塗料であって、二次電池の集電体１２，１６上に
塗布乾燥されて密着層１９，２１を形成する密着層用塗
料の改良である。その特徴ある構成は、平均体積粒径が
１〜１００μｍの粒子状のポリマー結着剤が１０個／ｍ
ｌ以上５００００個／ｍｌ以下の平均濃度で含有された
ところにある。請求項４に係る発明は、ポリマー結着剤
を有する密着層１９，２１を介して集電体１２，１６の
片面又は両面に活物質層１３，１７が設けられた二次電
池用電極の改良である。その特徴ある構成は、ポリマー
結着剤の一部が粒子状態で密着層１９，２１に存在し、
その粒子状ポリマー結着剤の平均体積粒径が１〜１００
μｍであるところにある。The invention according to claim 1 is
As shown in FIG. 1, a coating material containing a conductive auxiliary agent, a polymer binder, and a solvent, which is applied and dried on the current collectors 12 and 16 of the secondary battery to form the adhesive layers 19 and 21. It is an improvement of the paint for use. The characteristic constitution is that the particulate polymer binder having an average volume particle diameter of 1 to 100 μm is 10 / m.
It is contained at an average concentration of 1 or more and 50,000 cells / ml or less. The invention according to claim 4 is an improvement of an electrode for a secondary battery in which active material layers 13 and 17 are provided on one surface or both surfaces of current collectors 12 and 16 with adhesive layers 19 and 21 having a polymer binder interposed therebetween. Is. The characteristic constitution is that a part of the polymer binder is present in a particle state in the adhesion layers 19 and 21,
The average volume particle diameter of the particulate polymer binder is 1 to 100.
where it is μm.

【０００８】請求項４に係る発明では、密着層１９，２
１に存在する粒子状ポリマー結着剤が、粒子状態で存在
する導電性物質とともに集電体１２，１６と密着層１
９，２１との界面、及び活物質層１３，１７と密着層１
９，２１との界面に存在してその密着性を向上させる。
粒子状ポリマー結着剤が存在しない集電体１２，１６と
密着層１９，２１との界面、及び活物質層１３，１７と
密着層１９，２１との界面には導電性物質が存在し、そ
の導電性物質の存在によりその界面における電子の授受
が円滑に行われ、電気抵抗が低く維持される。更に、密
着層１９，２１に粒子状ポリマー結着剤が存在すること
により、密着層１９，２１の内部の凝集力が向上し、電
池のサイクル容量維持特性が向上する。In the invention according to claim 4, the adhesion layers 19 and 2 are
1. The particulate polymer binder present in No. 1 together with the conductive substances present in the state of particles and the current collectors 12, 16 and the adhesion layer 1
Interfaces with 9, 21 and active material layers 13, 17 with adhesion layer 1
It exists at the interface with 9, 21 and improves its adhesion.
Conductive substances exist at the interfaces between the current collectors 12 and 16 and the adhesion layers 19 and 21 in which no particulate polymer binder is present, and at the interfaces between the active material layers 13 and 17 and the adhesion layers 19 and 21. Due to the presence of the conductive substance, electrons are smoothly transferred and received at the interface, and the electric resistance is kept low. Further, the presence of the particulate polymer binder in the adhesion layers 19 and 21 improves the cohesive force inside the adhesion layers 19 and 21, and improves the cycle capacity maintenance characteristics of the battery.

【０００９】請求項１に係る密着層用塗料では、この塗
料を集電体１２，１６上に塗布乾燥することにより、ポ
リマー結着剤の一部が粒子状態で存在する密着層１９，
２１を比較的容易に形成することができる。ここで、ポ
リマー結着剤が、ポリフッ化ビニリデンにアクリル酸又
はメタクリル酸をグラフト重合した化合物、又はポリフ
ッ化ビニリデンを含む共重合体にアクリル酸又はメタク
リル酸をグラフト重合した化合物であれば、平均体積粒
径が１〜１００μｍの粒子状のポリマー結着剤を１０個
／ｍｌ以上５００００個／ｍｌ以下の平均濃度で比較的
容易に含有させることができる。そのポリマー結着剤が
５００００個／ｍｌを越えると、塗布乾燥することによ
り得られた密着層１９，２１の界面における導電性が低
下し、１０個／ｍｌ未満であると、その界面における密
着性が低下する。ここで、平均体積粒径が１〜１００μ
ｍの粒子状のポリマー結着剤は２０個／ｍｌ以上１００
００個／ｍｌ以下の平均濃度で含有されることが好まし
く、１５０個／ｍｌ以上７５００個／ｍｌ以下の平均濃
度で含有されることが更に好ましい。In the adhesive layer coating composition according to the first aspect, by coating and drying the coating composition on the current collectors 12 and 16, the adhesive layer 19 in which a part of the polymer binder exists in a particle state,
21 can be formed relatively easily. Here, if the polymer binder is a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on polyvinylidene fluoride, or a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on a copolymer containing polyvinylidene fluoride, the average volume is A particulate polymer binder having a particle diameter of 1 to 100 μm can be relatively easily contained at an average concentration of 10 / ml or more and 50,000 / ml or less. When the amount of the polymer binder exceeds 50,000 / ml, the conductivity at the interface of the adhesive layers 19 and 21 obtained by coating and drying decreases, and when it is less than 10 / ml, the adhesiveness at the interface is low. Is reduced. Here, the average volume particle size is 1 to 100 μm.
The particle size of the polymer binder is 20 or more per 100 ml.
The average concentration is preferably 00 / ml or less, more preferably 150 / ml or more and 7500 / ml or less.

【００１０】また、ポリマー結着剤が溶媒の溶解度パラ
メータに対し０．５（cal/cc）0.5以上異なる溶解度パ
ラメータを持つようにすれば、ポリマー結着剤が溶媒に
溶解され難くなり、比較的長期にわたって粒子状ポリマ
ー結着剤の平均体積粒径を１〜１００μｍの範囲に維持
させることができる。If the polymer binder has a solubility parameter different from the solubility parameter of the solvent by 0.5 (cal / cc) 0.5 or more, the polymer binder becomes difficult to be dissolved in the solvent, and the solubility is relatively high. The average volume particle size of the particulate polymer binder can be maintained in the range of 1 to 100 μm for a long period of time.

【００１１】なお、「溶解度パラメータ」とは分子間の
相互作用を定量的に表した値であり、その内容は、J.D.
Crowley, J. Paint Technol., 38, 269(1966); 39, 19
(1967), C.M.Hansen, J.Paint Technol.,39,104(1967);
39, 505(1967); 39, 511(1967)等に記されている。具
体的に、溶解度パラメータが近いポリマー結着剤と溶媒
の組み合わせは良好な溶解性を示し、溶解度パラメータ
が離れた組み合わせでは殆ど溶解しない。各溶媒および
結着剤としてのポリマーについての溶解度パラメータ値
は、例えば、「高分子データハンドブック」（高分子学
会編、培風館、1986年）、A.F.M.Barton, Handbookof S
olubility Parameters and Other Cohesion Parameter
s, CRC Press,Inc,Boca Raton, Fla.,1983、等に解説と
共に掲載されている。The "solubility parameter" is a value that quantitatively represents the interaction between molecules, and its content is JD
Crowley, J. Paint Technol., 38, 269 (1966); 39, 19
(1967), CMHansen, J.Paint Technol., 39,104 (1967);
39, 505 (1967); 39, 511 (1967), etc. Specifically, a combination of a polymer binder and a solvent having similar solubility parameters shows good solubility, and a combination having different solubility parameters hardly dissolves. The solubility parameter value for each solvent and the polymer as the binder is, for example, “Polymer Data Handbook” (edited by The Polymer Society of Japan, Baifukan, 1986), AFM Barton, Handbook of S.
olubility Parameters and Other Cohesion Parameter
s, CRC Press, Inc, Boca Raton, Fla., 1983, etc. along with explanations.

【００１２】請求項５に係る発明は、請求項４に係る発
明であって、ポリマー結着剤の主成分がフッ素系樹脂で
ある二次電池用電極である。請求項５に係る発明では、
ポリマー結着剤の主成分をフッ素系樹脂とすることによ
り電解液への耐久性が高い二次電池用電極を得ることが
できる。請求項６に係る発明は、請求項５に係る発明で
あって、ポリマー結着剤がポリフッ化ビニリデンにアク
リル酸又はメタクリル酸をモノマーとしてグラフト重合
した化合物である二次電池用電極である。請求項６に係
る発明では、変性物質としてアクリル酸又はメタクリル
酸を用いることにより集電体と良好な密着性を有する二
次電池用電極を得ることができる。The invention according to claim 5 is the invention according to claim 4, which is an electrode for a secondary battery, wherein the main component of the polymer binder is a fluororesin. In the invention according to claim 5,
By using a fluorine-based resin as the main component of the polymer binder, it is possible to obtain an electrode for a secondary battery that has high durability to an electrolytic solution. The invention according to claim 6 is the invention according to claim 5, wherein the polymer binder is a compound obtained by graft-polymerizing polyvinylidene fluoride with acrylic acid or methacrylic acid as a monomer. In the invention according to claim 6, by using acrylic acid or methacrylic acid as the modifying substance, it is possible to obtain a secondary battery electrode having good adhesion to the current collector.

【００１３】請求項７に係る発明は、請求項４ないし６
いずれかに係る発明であって、密着層１９，２１中の密
着層１９，２１の表面に平行な断面における粒子状ポリ
マー結着剤の面積密度が１〜１００個／ｃｍ2である二
次電池用電極である。請求項７に係る発明では、粒子状
ポリマー結着剤の面積密度を１〜１００個／ｃｍ2とす
ることにより、集電体１２，１６と密着層１９，２１と
の界面、及び活物質層１３，１７と密着層１９，２１と
の界面における粒子状ポリマー結着剤の分布の調和を図
り、その界面における密着性と導電性の双方を確保す
る。面積密度が１００個／ｃｍ2を越えると、上述した
界面における導電性が低下し、１個／ｃｍ2未満である
と、上述した界面における密着性が低下する。更に好ま
しい面積密度は１０〜８０個／ｃｍ2である。請求項８
に係る発明は、請求項４ないし７いずれかに記載の二次
電池用電極１１，１４を用いた二次電池である。請求項
８に係る発明では、サイクル容量維持特性が向上した二
次電池を得ることができる。The invention according to claim 7 is the invention according to claims 4 to 6.
The secondary battery according to any one of the inventions, wherein the area density of the particulate polymer binder in the cross section parallel to the surfaces of the adhesion layers 19 and 21 in the adhesion layers 19 and 21 is 1 to 100 / cm 2. It is an electrode for. In the invention according to claim 7, the area density of the particulate polymer binder is set to 1 to 100 pieces / cm 2 , whereby the interface between the current collectors 12 and 16 and the adhesion layers 19 and 21 and the active material layer. The distribution of the particulate polymer binder at the interfaces between the adhesive layers 13, 17 and the adhesive layers 19, 21 is harmonized, and both the adhesiveness and the electrical conductivity at the interfaces are secured. If the area density exceeds 100 / cm 2 , the conductivity at the above-mentioned interface will decrease, and if it is less than 1 / cm 2 , the adhesion at the above-mentioned interface will decrease. A more preferable area density is 10 to 80 pieces / cm 2 . Claim 8
The invention according to is a secondary battery using the secondary battery electrodes 11 and 14 according to any one of claims 4 to 7. In the invention according to claim 8, it is possible to obtain a secondary battery having improved cycle capacity maintaining characteristics.

【００１４】[0014]

【発明の実施の形態】次に本発明の実施の形態について
説明する。図１に示すように、リチウムイオンポリマー
二次電池は、正極電極１１と負極電極１４を積層して形
成された電極体１０を有する。この正極電極１１は、シ
ート状の正極集電体１２の表面に正極活物質層１３を形
成することにより作られ、負極電極１４は、シート状の
負極集電体１６の表面に負極活物質層１７を形成するこ
とにより作られる。正極活物質層１３と負極活物質層１
７の間に電解質層１８が介装された状態で正極電極１１
と負極電極１４が積層されて電極体１０が形成される。
ここで、正極活物質層１３にはＬｉＣｏＯ2等の活物質
の他に第１結着剤がこの活物質中に含まれてなり、負極
活物質層１７にはグラファイト系の活物質の他に第２結
着剤がこの活物質中に含まれてなる。BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. As shown in FIG. 1, the lithium ion polymer secondary battery has an electrode body 10 formed by stacking a positive electrode 11 and a negative electrode 14. The positive electrode 11 is made by forming a positive electrode active material layer 13 on the surface of a sheet-shaped positive electrode current collector 12, and the negative electrode 14 is formed on the surface of a sheet-shaped negative electrode current collector 16. Made by forming 17. Positive electrode active material layer 13 and negative electrode active material layer 1
With the electrolyte layer 18 interposed between the positive electrode 11
And the negative electrode 14 are laminated to form the electrode body 10.
Here, the positive electrode active material layer 13 contains a first binder in addition to the active material such as LiCoO 2 , and the negative electrode active material layer 17 contains the graphite-based active material in addition to the active material. A second binder is contained in this active material.

【００１５】正極集電体１２と正極活物質層１３との間
には第１密着層１９が形成され、負極集電体１６と負極
活物質層１７との間には第２密着層２１が形成される。
第１及び第２密着層１９，２１にはポリマー結着剤と導
電性物質の双方がそれぞれ含まれる。この実施の形態に
おけるポリマー結着剤は、第１結着剤又は第２結着剤を
変性物質により変性させた高分子化合物である。なお、
「変性」とは、性質が変わることを意味し、本明細書で
は、高分子化合物を変性物質により変性することによ
り、従来高分子化合物が持つ性質だけでなく、変性物質
が持つ性質も併せ持ったり、両者にない性質を新たに持
たせることを意味する。本発明の二次電池用電極は、こ
のポリマー結着剤の一部が粒子状態で密着層１９，２１
に存在する粒子状ポリマー結着剤であり、その粒子状ポ
リマー結着剤の平均体積粒径は１〜１００μｍであるこ
とを特徴とする。A first adhesion layer 19 is formed between the positive electrode current collector 12 and the positive electrode active material layer 13, and a second adhesion layer 21 is formed between the negative electrode current collector 16 and the negative electrode active material layer 17. It is formed.
The first and second adhesion layers 19 and 21 each contain both a polymer binder and a conductive substance. The polymer binder in this embodiment is a polymer compound obtained by modifying the first binder or the second binder with a modifying substance. In addition,
The term "modified" means that the properties are changed, and in this specification, by modifying a polymer compound with a modifying substance, not only the property of a conventional polymer compound but also the property of a modifying substance may be combined. , Means to have a new property that neither of them has. In the secondary battery electrode of the present invention, the polymer binder is partly in the state of particles in the adhesion layers 19 and 21.
The present invention is characterized in that the particulate polymer binder is present in 1. and the average volume particle diameter of the particulate polymer binder is 1 to 100 μm.

【００１６】このような構成の電池用電極１１，１４で
は、密着層１９，２１に存在する粒子状ポリマー結着剤
が、粒子状態で存在する導電性物質とともに集電体１
２，１６と密着層１９，２１との界面、及び活物質層１
３，１７と密着層１９，２１との界面に存在してその密
着性を向上させる。粒子状ポリマー結着剤が存在しない
集電体１２，１６と密着層１９，２１との界面、及び活
物質層１３，１７と密着層１９，２１との界面には導電
性物質が存在し、その導電性物質の存在によりその界面
における電子の授受が円滑に行われ、電気抵抗が低く維
持される。また、ポリマー結着剤の一部が粒子状態で密
着層１９，２１に存在することにより、密着層１９，２
１自体の機械的強度は向上し、この密着層１９，２１に
密着して積層される活物質層１３，１７の強度も向上さ
せることができる。更に、本発明における密着層１９，
２１は、ドット状、ストライプ状又は格子状等の限定さ
れた塗工パターンに形成する必要がなく、このような所
定の渡航パターンで形成する必要がある場合に比較し
て、その密着層１９，２１の形成が容易になる。In the battery electrodes 11 and 14 having such a structure, the particulate polymer binder present in the adhesion layers 19 and 21 together with the conductive substance present in the state of particles are the collector 1.
2, 16 and the interface between the adhesion layers 19 and 21, and the active material layer 1
It exists at the interface between the adhesive layers 3, 17 and the adhesive layers 19, 21 to improve the adhesiveness thereof. Conductive substances exist at the interfaces between the current collectors 12 and 16 and the adhesion layers 19 and 21 in which no particulate polymer binder is present, and at the interfaces between the active material layers 13 and 17 and the adhesion layers 19 and 21. Due to the presence of the conductive substance, electrons are smoothly transferred and received at the interface, and the electric resistance is kept low. Further, since a part of the polymer binder is present in the adhesive layers 19 and 21 in the form of particles, the adhesive layers 19 and 2 are
The mechanical strength of 1 itself can be improved, and the strength of the active material layers 13 and 17 which are laminated in close contact with the adhesion layers 19 and 21 can also be improved. Further, the adhesion layer 19 in the present invention,
21 does not need to be formed in a limited coating pattern such as a dot shape, a stripe shape, or a lattice shape, and compared with the case where it is necessary to form such a predetermined travel pattern, the adhesion layer 19, It becomes easy to form 21.

【００１７】次に、本発明の二次電池用電極の製造手順
を説明する。先ず、正極活物質層又は負極活物質層にそ
れぞれ含有する結着剤を変性物質により変性させ、この
変性高分子化合物を第１及び第２密着層のポリマー結着
剤とする。第１及び第２密着層１９，２１は化学的、電
気化学的、熱的に安定であることが要求されるため、活
物質に用いられる第１又は第２結着剤かつ変性高分子化
合物の基体となる高分子化合物は、分子内にフッ素を含
む高分子化合物であることが好ましい。このフッ素含有
高分子化合物としては、ポリテトラフルオロエチレン、
ポリクロロトリフルオロエチレン、ＰＶｄＦ、フッ化ビ
ニリデン−ヘキサフルオロプロピレン共重合体、ポリフ
ッ化ビニル等が挙げられる。Next, the procedure for manufacturing the secondary battery electrode of the present invention will be described. First, the binder contained in each of the positive electrode active material layer and the negative electrode active material layer is modified with a modifying substance, and the modified polymer compound is used as a polymer binder for the first and second adhesive layers. Since the first and second adhesion layers 19 and 21 are required to be chemically, electrochemically and thermally stable, the first and second binders and the modified polymer compound used in the active material may be used. The polymer compound serving as the substrate is preferably a polymer compound containing fluorine in the molecule. As the fluorine-containing polymer compound, polytetrafluoroethylene,
Examples thereof include polychlorotrifluoroethylene, PVdF, vinylidene fluoride-hexafluoropropylene copolymer, and polyvinyl fluoride.

【００１８】このフッ素含有高分子化合物を変性させる
手法として、グラフト重合、架橋等が挙げられる。グラ
フト重合に用いられる変性物質としては、エチレン、ス
チレン、ブタジエン、塩化ビニル、酢酸ビニル、アクリ
ル酸、アクリル酸メチル、メチルビニルケトン、アクリ
ルアミド、アクリロニトリル、塩化ビニリデン、メタク
リル酸、メタクリル酸メチル等の化合物が挙げられる。
特にアクリル酸、アクリル酸メチル、メタクリル酸、メ
タクリル酸メチルを用いた場合に集電体と良好な密着性
を得ることができる。架橋に用いられる変性物質として
は、不飽和結合を２つ以上有する化合物、例えばブタジ
エン、イソプレン等が挙げられる。また、架橋は加硫す
ることよって行ってもよい。Graft polymerization, cross-linking and the like can be mentioned as a method of modifying the fluorine-containing polymer compound. Examples of the modifier used in the graft polymerization include compounds such as ethylene, styrene, butadiene, vinyl chloride, vinyl acetate, acrylic acid, methyl acrylate, methyl vinyl ketone, acrylamide, acrylonitrile, vinylidene chloride, methacrylic acid, and methyl methacrylate. Can be mentioned.
Particularly, when acrylic acid, methyl acrylate, methacrylic acid, or methyl methacrylate is used, good adhesion with the current collector can be obtained. Examples of the modifying substance used for crosslinking include compounds having two or more unsaturated bonds, such as butadiene and isoprene. Further, the crosslinking may be carried out by vulcanization.

【００１９】このようにして得られた変性高分子化合物
を密着層のポリマー結着剤とし、このポリマー結着剤を
溶媒に溶解してポリマー溶液を作製し、ポリマー溶液中
に導電性物質を分散させて第１及び第２密着層用塗料を
調製する。導電性物質には粒径０．５〜３０μｍ、黒鉛
化度５０％以上の炭素材が用いられる。ポリマー結着剤
と導電性物質との重量比（ポリマー結着剤／導電性物
質）が１３／８７〜５０／５０になるように混合して密
着層用塗料を調製する。溶媒にはジメチルアセトアミド
（DiMethylAcetamide、以下、ＤＭＡという。）、ジメ
チルフォルムアミド、Ｎ-メチルピロリドンが用いられ
る。The modified polymer compound thus obtained is used as a polymer binder for the adhesion layer, the polymer binder is dissolved in a solvent to prepare a polymer solution, and a conductive substance is dispersed in the polymer solution. Then, the first and second adhesive layer coating materials are prepared. A carbon material having a particle size of 0.5 to 30 μm and a degree of graphitization of 50% or more is used as the conductive material. A polymer binder and a conductive substance are mixed so that the weight ratio (polymer binder / conductive substance) is 13/87 to 50/50 to prepare a coating material for an adhesion layer. Dimethylacetamide (hereinafter referred to as DMA), dimethylformamide, and N-methylpyrrolidone are used as the solvent.

【００２０】ここで、密着層用塗料の調製に際して、得
られた密着層用塗料は平均体積粒径が１〜１００μｍの
粒子状のポリマー結着剤が１０個／ｍｌ以上５００００
個／ｍｌ以下の平均濃度で含有されるように調製され
る。この場合、ポリマー結着剤が、ポリフッ化ビニリデ
ンにアクリル酸又はメタクリル酸をグラフト重合した化
合物、又はポリフッ化ビニリデンを含む共重合体にアク
リル酸又はメタクリル酸をグラフト重合した化合物であ
れば、平均体積粒径が１〜１００μｍの粒子状のポリマ
ー結着剤をが１０個／ｍｌ以上５００００個／ｍｌ以下
の平均濃度で比較的容易に含有させることができる。ま
た、ポリマー結着剤が溶媒の溶解度パラメータに対し
０．５（cal/cc）0.5以上異なる溶解度パラメータを持
つようにすれば、ポリマー結着剤が溶媒に溶解され難く
なり、比較的長期にわたって粒子状ポリマー結着剤の平
均体積粒径を１〜１００μｍの範囲に維持させることが
できる。Here, in the preparation of the coating material for the adhesion layer, the obtained coating material for the adhesion layer contains 10 or more particles of the polymer binder in the form of particles having an average volume particle diameter of 1 to 100 μm / ml of 50,000 or more.
It is prepared so as to be contained at an average concentration of 1 / ml or less. In this case, if the polymer binder is a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on polyvinylidene fluoride, or a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on a copolymer containing polyvinylidene fluoride, the average volume is The particulate polymer binder having a particle diameter of 1 to 100 μm can be relatively easily contained at an average concentration of 10 / ml or more and 50,000 / ml or less. Further, if the polymer binder has a solubility parameter different from the solubility parameter of the solvent by 0.5 (cal / cc) 0.5 or more, the polymer binder becomes difficult to be dissolved in the solvent, and particles are relatively long-term. The average volume particle size of the polymer binder can be maintained in the range of 1 to 100 μm.

【００２１】次いで、シート状の正極及び負極集電体１
２，１６をそれぞれ用意し、この正極及び負極集電体１
２，１６に調製した第１及び第２密着層用塗料をドクタ
ーブレード法によりそれぞれ塗工及び乾燥し、乾燥後の
密着層厚さが０．５〜３０μｍの第１及び第２密着層１
９，２１を有する正極又は負極集電体１２，１６を形成
する。乾燥後の密着層１９，２１の厚さは１〜１５μｍ
が好ましい。シート状の正極集電体１２としてはＡｌ箔
が、負極集電体１６としてはＣｕ箔がそれぞれ挙げられ
る。ここでドクターブレード法とは、キャリアフィルム
やエンドレスベルト等のキャリア上に載せて運ばれるス
リップの厚さをドクターブレードと呼ばれるナイフエッ
ジとキャリアとの間隔を調整することによってシートの
厚さを精密に制御する方法である。そして、この実施の
形態では、塗料に平均体積粒径が１〜１００μｍの粒子
状のポリマー結着剤を１０個／ｍｌ以上５００００個／
ｍｌ以下の平均濃度で含有させたので、この塗料を塗布
乾燥することにより、ポリマー結着剤の一部が粒子状態
で存在する密着層１９，２１を比較的容易に形成するこ
とができる。Next, the sheet-shaped positive and negative electrode current collectors 1
2 and 16 are prepared, and the positive and negative electrode current collectors 1
The coating compositions for the first and second adhesive layers prepared in Nos. 2 and 16 are applied and dried by the doctor blade method, respectively, and the first and second adhesive layers 1 having a dried adhesive layer thickness of 0.5 to 30 μm.
A positive electrode or negative electrode current collector 12, 16 having 9, 21 is formed. The thickness of the adhesion layers 19 and 21 after drying is 1 to 15 μm.
Is preferred. Examples of the sheet-shaped positive electrode current collector 12 include Al foil, and examples of the negative electrode current collector 16 include Cu foil. Here, the doctor blade method accurately adjusts the thickness of the sheet by adjusting the distance between the knife edge called the doctor blade and the carrier, which is the thickness of the slip carried on the carrier such as the carrier film or the endless belt. It is a control method. Further, in this embodiment, the coating material contains a particulate polymer binder having an average volume particle diameter of 1 to 100 μm in an amount of 10 pieces / ml or more and 50,000 pieces / ml or more.
Since it was contained at an average concentration of not more than ml, by coating and drying this coating material, it is possible to relatively easily form the adhesion layers 19 and 21 in which a part of the polymer binder is present in the form of particles.

【００２２】次に、正極活物質層１３及び負極活物質層
１７に必要な成分をそれぞれ混合して正極活物質層塗工
用スラリー及び負極活物質層塗工用スラリーをそれぞれ
調製する。得られた正極活物質層塗工用スラリーを第１
密着層１９を有する正極集電体１２上にドクターブレー
ド法により塗布して乾燥し、圧延する。また負極電極１
４も同様にして、得られた負極活物質層塗工用スラリー
を第２密着層２１を有する負極集電体１６上にドクター
ブレード法により塗布して乾燥し、圧延する。ここで、
正極又は負極活物質層１３，１７は乾燥後の厚さが、２
０〜２５０μｍとなるように形成する。このようにして
本発明の二次電池用正極電極１１及び本発明の二次電池
用負極電極１４を形成する。Next, the components necessary for the positive electrode active material layer 13 and the negative electrode active material layer 17 are mixed to prepare a positive electrode active material layer coating slurry and a negative electrode active material layer coating slurry, respectively. The obtained positive electrode active material layer coating slurry was first
The positive electrode current collector 12 having the adhesion layer 19 is coated with the doctor blade method, dried, and rolled. Also, the negative electrode 1
Similarly, for No. 4, the obtained negative electrode active material layer coating slurry is applied on the negative electrode current collector 16 having the second adhesion layer 21 by the doctor blade method, dried, and rolled. here,
The thickness of the positive electrode or negative electrode active material layers 13 and 17 after drying is 2
It is formed to have a thickness of 0 to 250 μm. Thus, the secondary battery positive electrode 11 of the present invention and the secondary battery negative electrode 14 of the present invention are formed.

【００２３】次に、本発明の二次電池を説明する。本発
明の二次電池は上述した二次電池用正極電極１１及び二
次電池用負極電極１４を用いたことを特徴とする。具体
的な製造手順は、先ず、上述した二次電池用正極電極１
１及び二次電池用負極電極１４を準備する。そして電解
質層１８に必要な成分を混合して電解質層塗工用スラリ
ーを調製する。得られた電解質層塗工用スラリーを剥離
紙上に電解質層１８の乾燥厚さが１０〜１５０μｍとな
るようにドクターブレード法により塗工及び乾燥し、剥
離紙より剥がして形成する。また、電解質層塗工用スラ
リーを正極電極１１表面や負極電極１４の表面に塗工及
び乾燥して電解質層１８を形成してもよい。そして正極
電極１１と電解質層１８と負極電極１４を順に積層し、
この積層物を熱圧着することにより、図１に示すシート
状の電極体１０を形成する。図示しないが、その後、こ
の電極体１０にＮｉからなる正極リード及び負極リード
をそれぞれ正極集電体１２及び負極集電体１６に溶接
し、開口部を有する袋状に加工したラミネートパッケー
ジ材に収納し、減圧条件下で熱圧着により開口部を封止
することにより本発明のリチウムイオンポリマー二次電
池が作製できる。Next, the secondary battery of the present invention will be described. The secondary battery of the present invention is characterized by using the above-mentioned secondary battery positive electrode 11 and secondary battery negative electrode 14. The specific manufacturing procedure is as follows. First, the positive electrode 1 for the secondary battery described above.
1 and the negative electrode 14 for secondary batteries are prepared. Then, necessary components are mixed with the electrolyte layer 18 to prepare a slurry for coating the electrolyte layer. The obtained slurry for coating an electrolyte layer is applied onto a release paper by a doctor blade method so that the dry thickness of the electrolyte layer 18 is 10 to 150 μm and dried, and peeled off from the release paper. Alternatively, the electrolyte layer 18 may be formed by applying and drying the electrolyte layer coating slurry on the surfaces of the positive electrode 11 and the negative electrode 14. Then, the positive electrode 11, the electrolyte layer 18, and the negative electrode 14 are sequentially stacked,
The sheet-shaped electrode body 10 shown in FIG. 1 is formed by thermocompression-bonding this laminate. Although not shown, thereafter, the positive electrode lead and the negative electrode lead made of Ni are welded to the positive electrode current collector 12 and the negative electrode current collector 16, respectively, and are housed in a laminated package material processed into a bag shape having an opening. Then, the lithium ion polymer secondary battery of the present invention can be produced by sealing the opening by thermocompression bonding under reduced pressure conditions.

【００２４】[0024]

【実施例】次に本発明の実施例を比較例とともに詳しく
説明する。 ＜実施例１＞結着剤として平均体積粒径２００μｍの粒
状のアクリル酸グラフト化ポリフッ化ビニリデン（（Ac
rylic Acid grafting PolyVinylidene Fluoride、以
下、ＡＡ−ｇ−ＰＶｄＦという）２ｇを用意し、溶媒と
してジメチルアセトアミド（DiMethylAcetamide、以
下、ＤＭＡという）９８ｇを用意し、両者を混合した。
この混合溶液を８５℃まで加熱するとともにホモジナイ
ザにより撹拌し続けた。撹拌中の溶液を時々採取し、透
明ガラス基板に液膜厚さが２００μｍ前後となるように
塗布し、光学顕微鏡によりポリマー結着剤粒子（未溶解
粒子）の平均体積粒径と、粒径１μｍ以上のポリマー結
着剤粒子（未溶解粒子）の個数とを測定した。EXAMPLES Next, examples of the present invention will be described in detail together with comparative examples. <Example 1> As a binder, granular acrylic acid grafted polyvinylidene fluoride ((Ac
2 g of rylic acid grafting PolyVinylidene Fluoride, hereinafter referred to as AA-g-PVdF) was prepared, 98 g of dimethylacetamide (DiMethylAcetamide, hereinafter referred to as DMA) was prepared as a solvent, and both were mixed.
The mixed solution was heated to 85 ° C. and continuously stirred by the homogenizer. The solution under stirring is sometimes sampled and applied on a transparent glass substrate so that the liquid film thickness is about 200 μm, and the average volume particle size of the polymer binder particles (undissolved particles) and the particle size of 1 μm are observed by an optical microscope. The number of the above-mentioned polymer binder particles (undissolved particles) was measured.

【００２５】ここで、粒子の粒径の測定は、等影円相当
径の定義とその測定方法を用いた。即ち、粒子径は粒子
の投影面積に等しい円の直径として測定し、その測定方
法は光学顕微鏡、電子顕微鏡、接写など、平面上に並ん
だ粒子を真上から観察し、その粒子の投影図によって粒
子径を決定した。そして、上述した測定方法により得ら
れた粒子径をｄ、その粒子の個数をｎとして、重み付け
により平均体積粒径Ｄを次の式により求めた。Ｄ＝［Σ
ｎｄ3／Σｎ］1/3そして、ポリマー結着剤粒子の平均体
積粒径が３０±１０μｍになり、粒径１μｍ以上のポリ
マー結着剤粒子の数が２０±１０個／ｃｍ2になったと
きに、撹拌を中止した。この混合溶液を実施例１のポリ
マー溶液とした。Here, for the measurement of the particle diameter of the particles, the definition of the equivalent circle diameter and its measuring method were used. That is, the particle diameter is measured as the diameter of a circle equal to the projected area of the particle, and the measuring method is to observe the particles arranged on a plane from directly above, such as an optical microscope, an electron microscope, and a close-up photograph, and The particle size was determined. Then, assuming that the particle diameter obtained by the above-described measuring method is d and the number of the particles is n, the average volume particle diameter D is obtained by weighting according to the following formula. D = [Σ
nd 3 / Σn] 1/3, and the average volume particle size of the polymer binder particles is 30 ± 10 μm, and the number of polymer binder particles having a particle size of 1 μm or more is 20 ± 10 particles / cm 2 . At times, stirring was discontinued. This mixed solution was used as the polymer solution of Example 1.

【００２６】＜実施例２＞結着剤として平均体積粒径２
００μｍの粒状のＡＡ−ｇ−ＰＶｄＦを１．５ｇ用意
し、９８ｇのＤＭＡと混合した。この混合溶液を８５℃
まで加熱するとともにホモジナイザにより撹拌し続け
た。このＡＡ−ｇ−ＰＶｄＦが完全に溶解した後、平均
体積粒径１００μｍの粒状のＡＡ−ｇ−ＰＶｄＦを０．
５ｇ更に添加し、ホモジナイザにより更に５分間撹拌し
てポリマー溶液とした。得られた溶液を採取し、透明ガ
ラス基板に液膜厚さが２００μｍ前後となるように塗布
し、光学顕微鏡によりポリマー結着剤粒子（未溶解粒
子）の平均体積粒径と、粒径１μｍ以上のポリマー結着
剤粒子（未溶解粒子）の個数とを測定した。その結果、
ポリマー結着剤粒子の平均体積粒径が２０±１０μｍに
なり、粒径１μｍ以上のポリマー結着剤粒子の数が２０
±１０個／ｃｍ2であった。この混合溶液を実施例２の
ポリマー溶液とした。<Example 2> Average volume particle size 2 as a binder
1.5 g of granular AA-g-PVdF of 00 μm was prepared and mixed with 98 g of DMA. This mixed solution is 85 ℃
It was heated up to and continued to stir with a homogenizer. After the AA-g-PVdF was completely dissolved, the granular AA-g-PVdF having an average volume particle size of 100 μm was added to 0.
Further, 5 g was added, and the mixture was further stirred for 5 minutes by a homogenizer to obtain a polymer solution. The obtained solution was sampled and applied on a transparent glass substrate so that the liquid film thickness was about 200 μm, and the average volume particle diameter of the polymer binder particles (undissolved particles) and the particle diameter of 1 μm or more were measured by an optical microscope. And the number of polymer binder particles (undissolved particles) of No. 1 were measured. as a result,
The average volume particle size of the polymer binder particles is 20 ± 10 μm, and the number of polymer binder particles having a particle size of 1 μm or more is 20.
It was ± 10 / cm 2 . This mixed solution was used as the polymer solution of Example 2.

【００２７】＜実施例３＞実施例１と同様に平均体積粒
径２００μｍのＡＡ−ｇ−ＰＶｄＦを２ｇと、ＤＭＡを
９８ｇ用意し、両者を実施例１と同一の条件で撹拌し続
けた。撹拌中の溶液を時々採取し、実施例一の条件で光
学顕微鏡によりポリマー結着剤粒子（未溶解粒子）の平
均体積粒径と、粒径１μｍ以上のポリマー結着剤粒子
（未溶解粒子）の個数とを測定した。ポリマー結着剤粒
子の平均体積粒径が１０±５μｍになり、粒径１μｍ以
上のポリマー結着剤粒子の数が１０±５個／ｃｍ2にな
ったときに、撹拌を中止した。この混合溶液を実施例３
のポリマー溶液とした。Example 3 As in Example 1, 2 g of AA-g-PVdF having an average volume particle size of 200 μm and 98 g of DMA were prepared, and both were continuously stirred under the same conditions as in Example 1. The solution under stirring was occasionally collected, and the average volume particle diameter of the polymer binder particles (undissolved particles) and the polymer binder particles (undissolved particles) having a particle diameter of 1 μm or more under the conditions of Example 1 were observed by an optical microscope. Was measured. When the average volume particle diameter of the polymer binder particles became 10 ± 5 μm and the number of the polymer binder particles having a particle diameter of 1 μm or more became 10 ± 5 particles / cm 2 , the stirring was stopped. This mixed solution was used in Example 3.
Of the polymer solution.

【００２８】＜実施例４＞結着剤として平均体積粒径２
００μｍの粒状のメタクリル酸グラフト化ポリフッ化ビ
ニリデンを２ｇと、ＤＭＡを９８ｇ用意し、両者を実施
例１と同一の条件で撹拌し続けた。撹拌中の溶液を時々
採取し、実施例１と同一の条件で光学顕微鏡によりポリ
マー結着剤粒子（未溶解粒子）の平均体積粒径と、粒径
１μｍ以上のポリマー結着剤粒子（未溶解粒子）の個数
とを測定した。ポリマー結着剤粒子の平均体積粒径が３
０±１０μｍになり、粒径１μｍ以上のポリマー結着剤
粒子の数が２０±１０個／ｃｍ2になったときに、撹拌
を中止した。この混合溶液を実施例４のポリマー溶液と
した。<Example 4> Average volume particle size of 2 as a binder
2 g of 00 μm granular methacrylic acid-grafted polyvinylidene fluoride and 98 g of DMA were prepared, and both were continuously stirred under the same conditions as in Example 1. The solution under stirring was sampled from time to time, and the average volume particle size of the polymer binder particles (undissolved particles) and the polymer binder particles having a particle size of 1 μm or more (undissolved) under the same conditions as in Example 1 were measured by an optical microscope. The number of particles) was measured. The average volume particle size of the polymer binder particles is 3
When the number became 0 ± 10 μm and the number of polymer binder particles having a particle size of 1 μm or more reached 20 ± 10 particles / cm 2 , stirring was stopped. This mixed solution was used as the polymer solution of Example 4.

【００２９】＜比較例１＞実施例１と同様に、結着剤と
して平均体積粒径２００μｍの粒状のＡＡ−ｇ−ＰＶｄ
Ｆを２ｇを用意し、溶媒として９８ｇのＤＭＡに混合し
た。この混合溶液を８５℃まで加熱するとともにＡＡ−
ｇ−ＰＶｄＦが完全に溶解するまでホモジナイザにより
撹拌し続け、溶液が完全に透明になった状態で攪拌を停
止した。得られたポリマー溶液を採取し、透明ガラス基
板に液膜厚さが２００μｍ前後となるように塗布し、光
学顕微鏡により粒径１μｍ以上のポリマー結着剤粒子
（未溶解粒子）がないことを確認した。この混合溶液を
比較例１のポリマー溶液とした。<Comparative Example 1> As in Example 1, as a binder, granular AA-g-PVd having an average volume particle size of 200 μm was used.
2 g of F was prepared and mixed with 98 g of DMA as a solvent. This mixed solution is heated to 85 ° C. and AA-
The stirring was continued with a homogenizer until the g-PVdF was completely dissolved, and the stirring was stopped when the solution became completely transparent. The obtained polymer solution was sampled and applied on a transparent glass substrate so that the liquid film thickness was about 200 μm, and it was confirmed by an optical microscope that there were no polymer binder particles (undissolved particles) with a particle size of 1 μm or more. did. This mixed solution was used as the polymer solution of Comparative Example 1.

【００３０】＜比較例２＞実施例２と同様に、結着剤と
して平均体積粒径２００μｍの粒状のＡＡ−ｇ−ＰＶｄ
Ｆを１．５ｇ用意し、９８ｇのＤＭＡと混合した。この
混合溶液を８５℃まで加熱するとともにホモジナイザに
より撹拌し続けた。このＡＡ−ｇ−ＰＶｄＦが完全に溶
解した後、平均体積粒径２００μｍの粒状のＡＡ−ｇ−
ＰＶｄＦを０．５ｇ更に添加し、ホモジナイザにより更
に１分間撹拌してポリマー溶液とした。得られた溶液を
採取し、透明ガラス基板に液膜厚さが２００μｍ前後と
なるように塗布し、光学顕微鏡によりポリマー結着剤粒
子（未溶解粒子）の平均体積粒径と、粒径１μｍ以上の
ポリマー結着剤粒子（未溶解粒子）の個数とを測定し
た。その結果、ポリマー結着剤粒子の平均体積粒径が１
２０±１０μｍになり、粒径１μｍ以上のポリマー結着
剤粒子の数が８０±１０個／ｃｍ2であった。この混合
溶液を比較例２のポリマー溶液とした。<Comparative Example 2> As in Example 2, as a binder, granular AA-g-PVd having an average volume particle size of 200 μm was used.
1.5 g of F was prepared and mixed with 98 g of DMA. The mixed solution was heated to 85 ° C. and continuously stirred by the homogenizer. After the AA-g-PVdF was completely dissolved, granular AA-g- having an average volume particle size of 200 μm was used.
0.5 g of PVdF was further added, and the mixture was further stirred for 1 minute with a homogenizer to obtain a polymer solution. The obtained solution was collected and applied on a transparent glass substrate so that the liquid film thickness was about 200 μm, and the average volume particle diameter of the polymer binder particles (undissolved particles) and the particle diameter of 1 μm or more were measured by an optical microscope. And the number of polymer binder particles (undissolved particles) of No. 1 were measured. As a result, the average volume particle size of the polymer binder particles is 1
It was 20 ± 10 μm, and the number of polymer binder particles having a particle size of 1 μm or more was 80 ± 10 particles / cm 2 . This mixed solution was used as a polymer solution of Comparative Example 2.

【００３１】＜比較例３＞実施例２と同様に、結着剤と
して平均体積粒径２００μｍの粒状のＡＡ−ｇ−ＰＶｄ
Ｆを１ｇ用意し、９８ｇのＤＭＡと混合した。この混合
溶液を８５℃まで加熱するとともにホモジナイザにより
撹拌し続けた。このＡＡ−ｇ−ＰＶｄＦが完全に溶解し
た後、平均体積粒径１００μｍの粒状のＡＡ−ｇ−ＰＶ
ｄＦを１ｇ更に添加し、ホモジナイザにより更に２分間
撹拌してポリマー溶液とした。得られた溶液を採取し、
透明ガラス基板に液膜厚さが２００μｍ前後となるよう
に塗布し、光学顕微鏡によりポリマー結着剤粒子（未溶
解粒子）の平均体積粒径と、粒径１μｍ以上のポリマー
結着剤粒子（未溶解粒子）の個数とを測定した。その結
果、ポリマー結着剤粒子の平均体積粒径が６０±１０μ
ｍになり、粒径１μｍ以上のポリマー結着剤粒子の数が
１５０±１０個／ｃｍ2であった。この混合溶液を比較
例３のポリマー溶液とした。<Comparative Example 3> As in Example 2, as a binder, granular AA-g-PVd having an average volume particle size of 200 μm was used.
1 g of F was prepared and mixed with 98 g of DMA. The mixed solution was heated to 85 ° C. and continuously stirred by the homogenizer. After this AA-g-PVdF was completely dissolved, granular AA-g-PV with an average volume particle size of 100 μm was used.
1 g of dF was further added, and the mixture was further stirred for 2 minutes by a homogenizer to obtain a polymer solution. Collecting the resulting solution,
It is applied on a transparent glass substrate so that the liquid film thickness is about 200 μm, and the average volume particle size of the polymer binder particles (undissolved particles) and the polymer binder particles (particle size of 1 μm or more) The number of dissolved particles) was measured. As a result, the average volume particle size of the polymer binder particles was 60 ± 10μ.
The number of polymer binder particles having a particle size of 1 μm or more was 150 ± 10 particles / cm 2 . This mixed solution was used as a polymer solution of Comparative Example 3.

【００３２】＜比較例４＞実施例４と同様に、結着剤と
して平均体積粒径２００μｍの粒状のメタクリル酸グラ
フト化ポリフッ化ビニリデン２ｇを９８ｇのＤＭＡに混
合し、この混合溶液を８５℃まで加熱するとともにポリ
テトラフルオロエチレンが完全に溶解するまでホモジナ
イザにより撹拌した。得られたポリマー溶液を採取し、
透明ガラス基板に液膜厚さが２００μｍ前後となるよう
に塗布し、光学顕微鏡により粒径１μｍ以上のポリマー
結着剤粒子（未溶解粒子）がないことを確認した。この
混合溶液を比較例４のポリマー溶液とした。Comparative Example 4 As in Example 4, 2 g of granular methacrylic acid grafted polyvinylidene fluoride having an average volume particle size of 200 μm was mixed with 98 g of DMA as a binder, and the mixed solution was heated to 85 ° C. The mixture was heated and stirred by a homogenizer until the polytetrafluoroethylene was completely dissolved. Collecting the obtained polymer solution,
It was applied on a transparent glass substrate so that the liquid film thickness was around 200 μm, and it was confirmed by an optical microscope that there were no polymer binder particles (undissolved particles) having a particle size of 1 μm or more. This mixed solution was used as a polymer solution of Comparative Example 4.

【００３３】＜比較試験及び評価＞ 銅箔及びアルミ箔に対する接着性試験 先ず、実施例１〜４及び比較例１〜４で得られたポリマ
ー溶液をそれぞれ幅３０ｍｍ、長さ２００ｍｍ、厚さ１
４μｍの表面を脱脂したＣｕ箔に均一に塗布し、その上
に、幅１０ｍｍ、長さ１００ｍｍ、厚さ２０μｍの表面
を脱脂したＡｌ箔を貼り付けて接着性試験用ピール試料
を作製した。作製した試料を乾燥機により大気中で８０
℃、５日間の乾燥を行った。次に、乾燥した試料を剥離
試験器によりＣｕ箔及びＡｌ箔に対する結着剤の評価を
行った。剥離試験方法は、測定する際に試料のＣｕ箔側
を試験台に固定し、Ｃｕ箔に接着しているＡｌ箔を垂直
上方に１００ｍｍ／分の速度で引っ張り上げて、Ａｌ箔
がＣｕ箔から引き剥がすのにかかる力を測定した。な
お、実施例１のポリマー溶液を用いて塗布した銅箔を乾
燥した後、結着剤粒子の電子顕微鏡写真を図２に示す。<Comparison Test and Evaluation> Adhesion Test for Copper Foil and Aluminum Foil First, the polymer solutions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were 30 mm wide, 200 mm long and 1 mm thick, respectively.
A Cu foil having a degreased surface of 4 μm was uniformly applied, and an Al foil having a degreased surface having a width of 10 mm, a length of 100 mm and a thickness of 20 μm was attached to the Cu foil to prepare a peel test sample for adhesion test. The prepared sample is dried in air at 80
It was dried at 5 ° C for 5 days. Next, the dried sample was evaluated for the binder with respect to the Cu foil and the Al foil by a peel tester. In the peeling test method, the Cu foil side of the sample is fixed to the test stand at the time of measurement, and the Al foil adhered to the Cu foil is pulled vertically upward at a speed of 100 mm / min to remove the Al foil from the Cu foil. The force required for peeling was measured. An electron micrograph of the binder particles is shown in FIG. 2 after the copper foil coated with the polymer solution of Example 1 was dried.

【００３４】 電池の密着層に用いられる場合の電池
のサイクル容量維持特性試験 先ず、実施例１〜４及び比較例１〜４で得られたポリマ
ー溶液１００ｇに、比表面積１５０ｍ2／ｇの黒鉛粉末
８ｇ及びＤＭＡ８０ｇを加えて攪拌し、密着層用塗料を
調製した。次いで、正極集電体として厚さ２０μｍ、幅
２５０μｍのＡｌ箔を用意し、このＡｌ箔に調製した密
着層用塗料をドクターブレード法により塗工及び乾燥
し、乾燥後の密着層厚さを２０±１μｍの範囲内に制御
した。また負極集電体として厚さ１４μｍ、幅２５０μ
ｍのＣｕ箔を用意し、このＣｕ箔表面に調製した密着層
用塗料をドクターブレード法により塗工及び乾燥し、乾
燥後の密着層厚さを２０±１μｍの範囲内に制御した。
次に、下記表１に示される各成分をボールミルで２時間
混合することにより、正極活物質層塗工用スラリー、負
極活物質層塗工用スラリー及び電解質層塗工用スラリー
をそれぞれ調製した。Cycle Capacity Maintenance Characteristic Test of Battery when Used for Adhesion Layer of Battery First, 100 g of the polymer solutions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were mixed with graphite powder having a specific surface area of 150 m 2 / g. 8 g and 80 g of DMA were added and stirred to prepare a coating material for adhesion layer. Then, an Al foil having a thickness of 20 μm and a width of 250 μm was prepared as a positive electrode current collector, the adhesive layer coating material prepared on the Al foil was applied and dried by a doctor blade method, and the adhesive layer thickness after drying was 20. It was controlled within a range of ± 1 μm. The negative electrode current collector has a thickness of 14 μm and a width of 250 μm.
m Cu foil was prepared, the adhesive layer coating material prepared on the Cu foil surface was applied and dried by a doctor blade method, and the dried adhesive layer thickness was controlled within a range of 20 ± 1 μm.
Next, the components shown in Table 1 below were mixed in a ball mill for 2 hours to prepare a positive electrode active material layer coating slurry, a negative electrode active material layer coating slurry, and an electrolyte layer coating slurry.

【００３５】[0035]

【表１】 [Table 1]

【００３６】得られた正極活物質塗工用スラリーを密着
層を有するＡｌ箔表面に正極活物質層の乾燥厚さが８０
μｍとなるようにドクターブレード法により塗工及び乾
燥し、圧延することにより正極を形成した。同様に、負
極活物質塗工用スラリーを密着層を有するＣｕ箔表面に
負極活物質層の乾燥厚さが８０μｍとなるようにドクタ
ーブレード法により塗工及び乾燥し、圧延することによ
り負極を形成した。更に電解質層塗工用スラリーを乾燥
厚さが５０μｍとなるように正極及び負極にそれぞれド
クターブレード法により塗工し、これらの電解質層を有
する正極及び負極を積層して熱圧着することにより、シ
ート状の電極体を作製した。作製した電極体にＮｉから
なる正極リード及び負極リードをそれぞれ正極集電体、
負極集電体に溶接し、開口部を有する袋状に加工したラ
ミネートパッケージ材に収納し、減圧条件下で開口部を
熱圧着して封止し、シート状電池を作製した。The obtained positive electrode active material coating slurry was applied to an Al foil surface having an adhesion layer so that the dry thickness of the positive electrode active material layer was 80.
The positive electrode was formed by applying and drying by a doctor blade method so as to have a thickness of μm, and rolling. Similarly, the negative electrode active material coating slurry is applied to the surface of the Cu foil having the adhesion layer by the doctor blade method so that the dry thickness of the negative electrode active material layer is 80 μm, dried, and rolled to form a negative electrode. did. Further, a slurry for coating an electrolyte layer is applied to each of the positive electrode and the negative electrode by a doctor blade method so that the dry thickness becomes 50 μm, and the positive electrode and the negative electrode having these electrolyte layers are laminated and thermocompression bonded to form a sheet. The electrode body having the shape of a circle was prepared. A positive electrode lead made of Ni and a negative electrode lead made of Ni were added to the produced electrode body, respectively.
A sheet-shaped battery was manufactured by welding to a negative electrode current collector, storing in a bag-shaped laminated package material having an opening, and thermocompressing and sealing the opening under a reduced pressure condition.

【００３７】次に、得られたシート状電池を最大充電電
圧４Ｖ、充電電流０．５Ａの条件で２．５時間の充電を
行う充電工程と、０．５Ａの定電流放電で放電電圧が最
低放電電圧となる２．７５Ｖとなるまで放電を行う放電
工程とを１サイクルとして充放電サイクルを繰り返し、
各サイクルの充放電容量をそれぞれ測定して初期放電容
量の８０％迄低下するサイクル数を測定した。Next, the obtained sheet-shaped battery is charged for 2.5 hours under the conditions of maximum charging voltage of 4 V and charging current of 0.5 A, and the discharging voltage becomes the minimum by constant current discharging of 0.5 A. The charging / discharging cycle is repeated with one cycle including a discharging step of discharging until the discharging voltage becomes 2.75V.
The charge / discharge capacity of each cycle was measured to measure the number of cycles in which the initial discharge capacity was reduced to 80%.

【００３８】 電池の密着層に用いられる場合の密着
層の集電体に対する密着性試験 先ず、実施例１〜４及び比較例１〜４で得られたポリマ
ー溶液を用いて前述した評価試験のシート状電池と同
様のシート状電池をそれぞれ作製した。次いで、この電
池を７０℃環境下で、上記評価試験と同様の条件での
充放電サイクルを１００サイクル行った。その後、１０
０サイクルの充放電を終えたシート状電池の収納パッケ
ージを除去し、電池の正極と負極を引き剥がしてそれぞ
れを分離し、分離した正極の密着層及び負極の密着層を
ピンセットでつまんで引っ張ったときに、密着層が集電
体から剥離するか否かを確認した。上記評価試験〜
における評価結果を表２にそれぞれ示す。なお、表２中
の評価試験欄における記号は、次の意味である。 ◎：密着層が集電体への密着が極めて良好であり、剥離
しない。 ○：密着層が集電体から部分的に剥離する。 ×：密着層が集電体から完全に剥離する。Adhesion Test of Adhesion Layer to Current Collector when Used for Adhesion Layer of Battery First, the sheet of the evaluation test described above using the polymer solutions obtained in Examples 1 to 4 and Comparative Examples 1 to 4 Sheet-shaped batteries similar to the battery cells were produced. Next, this battery was subjected to 100 charge / discharge cycles under the same conditions as in the above evaluation test under a 70 ° C. environment. Then 10
The storage package of the sheet-shaped battery that had been charged and discharged for 0 cycles was removed, the positive electrode and the negative electrode of the battery were peeled off to separate them, and the separated positive electrode adhesion layer and negative electrode adhesion layer were pinched with tweezers and pulled. At this time, it was confirmed whether or not the adhesive layer was peeled off from the current collector. Evaluation test above
The evaluation results in Table 2 are shown in Table 2, respectively. The symbols in the evaluation test column in Table 2 have the following meanings. ⊚: The adhesion layer has very good adhesion to the current collector and does not peel off. ◯: The adhesion layer is partially peeled from the current collector. X: The adhesion layer is completely peeled off from the current collector.

【００３９】[0039]

【表２】 [Table 2]

【００４０】表２から明らかなように、評価試験のＣ
ｕ箔及びＡｌ箔に対する接着性試験では、実施例１〜４
のポリマー溶液を用いてＣｕ箔に接着したＡｌ箔は、そ
のＣｕ箔からの剥離強度が全て９．８Ｎ／ｃｍ以上であ
ることを示した。これに対して、比較例１〜４のポリマ
ー溶液を用いた場合の剥離強度は、実施例１〜４の剥離
強度に対してそれぞれ２．９４〜４．９０Ｎ／ｃｍ低く
なっている。これは粒子状ポリマー結着剤の有無に起因
するものと考えられ、その粒子状ポリマー結着剤の存在
により接着性が向上したことが原因と考えられる。 次
に、評価試験のサイクル容量維持特性試験では、比較
例１〜４のポリマー溶液を用いた電池の８０％容量サイ
クル数に比べて実施例１〜４のポリマー結着剤を用いた
電池の８０％容量サイクル数はそれぞれ高いサイクル数
を示している。これは、実施例１〜４のポリマー結着剤
が接着特性が優れており、電解液への耐久性が高いた
め、サイクル容量維持特性が向上されたと考えられる。As is clear from Table 2, C of the evaluation test
In the adhesion test for u foil and Al foil, Examples 1 to 4 were used.
The Al foils adhered to the Cu foil using the polymer solution of No. 3 showed that the peel strength from the Cu foil was all 9.8 N / cm or more. On the other hand, the peel strengths when the polymer solutions of Comparative Examples 1 to 4 were used were 2.94 to 4.90 N / cm lower than the peel strengths of Examples 1 to 4, respectively. This is considered to be due to the presence or absence of the particulate polymer binder, and it is considered that the presence of the particulate polymer binder improved the adhesiveness. Next, in the cycle capacity maintenance characteristic test of the evaluation test, compared with the 80% capacity cycle number of the batteries using the polymer solutions of Comparative Examples 1 to 4, 80% of the batteries using the polymer binders of Examples 1 to 4 were compared. Each% capacity cycle number indicates a high cycle number. It is considered that this is because the polymer binders of Examples 1 to 4 had excellent adhesive properties and high durability to the electrolytic solution, and therefore the cycle capacity maintaining properties were improved.

【００４１】また、ポリマー溶液に存在する粒子の平均
体積粒径が１００μｍ以下であって、粒径１μｍ以上の
粒子数が１００個／ｃｍ2以下である実施例１〜３は、
平均体積粒径が１００μｍ以上であって、粒径１μｍ以
上の粒子数が１００個／ｃｍ 2以上の比較例２及び３に
比較してそれぞれ高いサイクル数を示している。更に、
評価試験の密着層の集電体に対する密着性試験では、
実施例１及び２並びに比較例１及び２が同じレベルの高
い密着性を示した。一方、実施例１〜３と実施例４を比
較すると、メタクリル酸グラフト化ポリフッ化ビニリデ
ンを結着剤として用いる場合、接着特性がＡＡ−ｇ−Ｐ
ＶｄＦを用いた場合より落ちているが、密着特性が不良
なメタクリル酸グラフト化ポリフッ化ビニリデンをポリ
マー結着剤として用いた比較例４であっても、そのポリ
マー結着剤の一部を粒子状態で密着層に存在させた実施
例４ではその密着特性を改善できることが判る。Also, the average of the particles present in the polymer solution
Volume particle size of 100 μm or less and particle size of 1 μm or more
100 particles / cm2Examples 1-3 below are
The average volume particle size is 100 μm or more and the particle size is 1 μm or more.
The number of particles above is 100 / cm 2In Comparative Examples 2 and 3 above
In comparison, each shows a high cycle number. Furthermore,
In the adhesion test for the current collector of the adhesion layer in the evaluation test,
Examples 1 and 2 and Comparative Examples 1 and 2 have the same high level.
Showed good adhesion. On the other hand, comparing Examples 1 to 3 with Example 4
By comparison, methacrylic acid grafted polyvinylidene fluoride
When used as a binder, the adhesive properties are AA-g-P
Although it is lower than when VdF is used, the adhesion characteristics are poor.
Methacrylic acid grafted polyvinylidene fluoride
Even in Comparative Example 4 used as the mer binder, the poly
Implementation of a part of the mer binder in the state of particles in the adhesion layer
In Example 4, it can be seen that the adhesion property can be improved.

【００４２】[0042]

【発明の効果】以上述べたように、本発明によれば、ポ
リマー結着剤を有する密着層を介して集電体の片面又は
両面に活物質層が設けられた二次電池用電極の、そのポ
リマー結着剤の一部を粒子状態で密着層に存在させ、そ
の粒子状ポリマー結着剤の平均体積粒径を１〜１００μ
ｍとしたので、密着層に存在する粒子状ポリマー結着剤
が、粒子状態で存在する導電性物質とともに集電体と密
着層との界面、及び活物質層と密着層との界面に存在し
てその密着性を向上させることができる。一方、粒子状
ポリマー結着剤が存在しない集電体と密着層との界面、
及び活物質層と密着層との界面には導電性物質が存在
し、その導電性物質の存在によりその界面における電子
の授受が円滑に行われ、電気抵抗を低く維持することが
できる。As described above, according to the present invention, an electrode for a secondary battery in which an active material layer is provided on one side or both sides of a current collector through an adhesion layer having a polymer binder, Part of the polymer binder is present in the state of particles in the adhesion layer, and the average volume particle diameter of the particulate polymer binder is 1 to 100 μm.
Therefore, the particulate polymer binder present in the adhesive layer is present at the interface between the current collector and the adhesive layer and the interface between the active material layer and the adhesive layer together with the conductive substance existing in the particle state. The adhesion can be improved. On the other hand, the interface between the current collector and the adhesive layer in which the particulate polymer binder does not exist,
Also, a conductive substance exists at the interface between the active material layer and the adhesive layer, and the presence of the conductive substance allows electrons to be transferred and received smoothly at the interface, so that the electrical resistance can be kept low.

【００４３】この場合、ポリマー結着剤の主成分をフッ
素系樹脂とすれば、電解液への耐久性が高い二次電池用
電極を得ることができ、ポリマー結着剤がポリフッ化ビ
ニリデンにアクリル酸又はメタクリル酸をモノマーとし
てグラフト重合した化合物であれば、集電体と良好な密
着性を有する二次電池用電極を得ることができる。ま
た、密着層中の密着層の表面に平行な断面における粒子
状ポリマー結着剤の面積密度が１〜１００個／ｃｍ2で
あれば、集電体と密着層との界面、及び活物質層と密着
層との界面における粒子状ポリマー結着剤の分布の調和
を図り、その界面における密着性と導電性の双方を確保
することができる。そして、この二次電池用電極を用い
た二次電池は、サイクル容量維持特性が向上したものに
なる。In this case, when the main component of the polymer binder is a fluororesin, an electrode for a secondary battery having high durability to an electrolytic solution can be obtained, and the polymer binder is polyvinylidene fluoride and acrylic resin. If the compound is obtained by graft-polymerizing acid or methacrylic acid as a monomer, an electrode for a secondary battery having good adhesion to the current collector can be obtained. Further, when the area density of the particulate polymer binder in the cross section parallel to the surface of the adhesive layer in the adhesive layer is 1 to 100 / cm 2 , the interface between the current collector and the adhesive layer and the active material layer The distribution of the particulate polymer binder at the interface between the adhesive layer and the adhesive layer can be harmonized, and both adhesiveness and conductivity at the interface can be secured. A secondary battery using this secondary battery electrode has improved cycle capacity maintenance characteristics.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明のリチウムイオンポリマー二次電池の電
極体を示す部分断面構成図。FIG. 1 is a partial cross-sectional configuration diagram showing an electrode body of a lithium ion polymer secondary battery of the present invention.

【図２】実施例１のポリマー溶液を塗布乾燥した結着剤
粒子の電子顕微鏡写真図。2 is an electron micrograph of binder particles obtained by coating and drying the polymer solution of Example 1. FIG.

【符号の説明】[Explanation of symbols]

１１ 正極電極 １２ 正極集電体 １３ 正極活物質層 １４ 負極電極 １６ 負極集電体 １７ 負極活物質層 １８ ポリマー電解質層 １９ 第１密着層 ２１ 第２密着層 11 Positive electrode 12 Positive electrode current collector 13 Positive electrode active material layer 14 Negative electrode 16 Negative electrode current collector 17 Negative electrode active material layer 18 Polymer Electrolyte Layer 19 First adhesion layer 21 Second adhesion layer

【手続補正書】[Procedure amendment]

【提出日】平成１４年４月１２日（２００２．４．１
２）[Submission date] April 12, 2002 (2002.4.1)
2)

【手続補正１】[Procedure Amendment 1]

【補正対象書類名】図面[Document name to be corrected] Drawing

【補正対象項目名】図２[Name of item to be corrected] Figure 2

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【図２】 [Fig. 2]

───────────────────────────────────────────────────── フロントページの続き (72)発明者 水口 暁夫 茨城県那珂郡那珂町向山1002番地14 三菱 マテリアル株式会社総合研究所那珂研究セ ンター内 (72)発明者 樋上 晃裕 茨城県那珂郡那珂町向山1002番地14 三菱 マテリアル株式会社総合研究所那珂研究セ ンター内 (72)発明者 張 守斌 茨城県那珂郡那珂町向山1002番地14 三菱 マテリアル株式会社総合研究所那珂研究セ ンター内 Ｆターム(参考） 5H017 AA03 AS01 BB08 BB12 BB14 CC01 DD05 EE10 HH00 HH03 HH04 HH06 5H029 AJ03 AJ05 AK03 AL07 AM03 BJ04 BJ12 CJ06 CJ22 DJ07 DJ08 EJ12 HJ02 HJ05 HJ07 5H050 AA07 BA17 CA08 CB08 DA02 DA03 DA04 DA09 EA24 FA02 FA18 GA02 GA10 GA22 HA05 HA07 HA10    ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akio Mizuguchi             1002 Mukayama, Naka-machi, Naka-machi, Naka-gun, Ibaraki Prefecture 14 Mitsubishi             Materials Research Laboratories Naka Research Center             In the center (72) Inventor Akihiro Higami             1002 Mukayama, Naka-machi, Naka-machi, Naka-gun, Ibaraki Prefecture 14 Mitsubishi             Materials Research Laboratories Naka Research Center             In the center (72) Inventor Zhang Morin             1002 Mukayama, Naka-machi, Naka-machi, Naka-gun, Ibaraki Prefecture 14 Mitsubishi             Materials Research Laboratories Naka Research Center             In the center F term (reference) 5H017 AA03 AS01 BB08 BB12 BB14                       CC01 DD05 EE10 HH00 HH03                       HH04 HH06                 5H029 AJ03 AJ05 AK03 AL07 AM03                       BJ04 BJ12 CJ06 CJ22 DJ07                       DJ08 EJ12 HJ02 HJ05 HJ07                 5H050 AA07 BA17 CA08 CB08 DA02                       DA03 DA04 DA09 EA24 FA02                       FA18 GA02 GA10 GA22 HA05                       HA07 HA10

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 導電助剤とポリマー結着剤及び溶媒を含
む塗料であって、二次電池の集電体(12,16)上に塗布乾
燥されて密着層(19,21)を形成する密着層用塗料におい
て、 平均体積粒径が１〜１００μｍの粒子状の前記ポリマー
結着剤が１０個／ｍｌ以上５００００個／ｍｌ以下の平
均濃度で含有されたことを特徴とする密着層用塗料。1. A paint containing a conductive aid, a polymer binder and a solvent, which is applied and dried on a current collector (12, 16) of a secondary battery to form an adhesion layer (19, 21). The adhesive layer coating material, wherein the particulate polymer binder having an average volume particle diameter of 1 to 100 μm is contained at an average concentration of 10 / ml or more and 50,000 / ml or less. . 【請求項２】 ポリマー結着剤が、ポリフッ化ビニリデ
ンにアクリル酸又はメタクリル酸をグラフト重合した化
合物、又はポリフッ化ビニリデンを含む共重合体にアク
リル酸又はメタクリル酸をグラフト重合した化合物であ
る請求項１記載の密着層用塗料。2. The polymer binder is a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on polyvinylidene fluoride, or a compound obtained by graft-polymerizing acrylic acid or methacrylic acid on a copolymer containing polyvinylidene fluoride. The adhesive layer coating composition according to 1. 【請求項３】 ポリマー結着剤が溶媒の溶解度パラメー
タに対し０．５（cal/cc）0.5以上異なる溶解度パラメ
ータを持つ請求項１又は２記載の密着層用塗料。3. The coating material for an adhesive layer according to claim 1, wherein the polymer binder has a solubility parameter different by 0.5 (cal / cc) 0.5 or more with respect to the solubility parameter of the solvent. 【請求項４】 ポリマー結着剤を有する密着層(19,21)
を介して集電体(12,16)の片面又は両面に活物質層(13,1
7)が設けられた二次電池用電極において、 前記ポリマー結着剤の一部が粒子状態で前記密着層(19,
21)に存在し、 粒子状ポリマー結着剤の平均体積粒径が１〜１００μｍ
であることを特徴とする二次電池用電極。4. Adhesion layer (19, 21) having a polymeric binder
Through the active material layer (13, 1) on one or both sides of the current collector (12, 16).
In the secondary battery electrode provided with 7), a part of the polymer binder is in the particle state of the adhesion layer (19,
21), and the average volume particle size of the particulate polymer binder is 1 to 100 μm.
An electrode for a secondary battery, characterized in that 【請求項５】 ポリマー結着剤の主成分がフッ素系樹脂
である請求項４記載の二次電池用電極。5. The electrode for a secondary battery according to claim 4, wherein the main component of the polymer binder is a fluororesin. 【請求項６】 ポリマー結着剤がポリフッ化ビニリデン
にアクリル酸又はメタクリル酸をモノマーとしてグラフ
ト重合した化合物である請求項５記載の二次電池用電
極。6. The electrode for a secondary battery according to claim 5, wherein the polymer binder is a compound obtained by graft-polymerizing polyvinylidene fluoride with acrylic acid or methacrylic acid as a monomer. 【請求項７】 密着層(19,21)中の前記密着層(19,21)の
表面に平行な断面における粒子状ポリマー結着剤の面積
密度が１〜１００個／ｃｍ2である請求項４ないし６い
ずれか記載の二次電池用電極。7. The areal density of the particulate polymer binder in a cross section parallel to the surface of the adhesive layer (19,21) in the adhesive layer (19,21) is 1 to 100 / cm 2. An electrode for a secondary battery according to any one of 4 to 6. 【請求項８】 請求項４ないし７いずれかに記載の二次
電池用電極(11,14)を用いた二次電池。8. A secondary battery using the secondary battery electrode (11, 14) according to claim 4.
JP2002109835A 2001-09-28 2002-04-12 Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them Pending JP2003173781A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2002109835A JP2003173781A (en) 2001-09-28 2002-04-12 Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2001303054 2001-09-28
JP2001-303054 2001-09-28
JP2002109835A JP2003173781A (en) 2001-09-28 2002-04-12 Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them

Publications (1)

Publication Number Publication Date
JP2003173781A true JP2003173781A (en) 2003-06-20

Family

ID=26623397

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2002109835A Pending JP2003173781A (en) 2001-09-28 2002-04-12 Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them

Country Status (1)

Country Link
JP (1) JP2003173781A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009538495A (en) * 2005-09-02 2009-11-05 エイ １２３ システムズ，インク． Nanocomposite electrodes and related equipment
WO2011070661A1 (en) * 2009-12-10 2011-06-16 トヨタ自動車株式会社 Process for producing electrode for battery
JP2013016452A (en) * 2011-07-06 2013-01-24 Samsung Sdi Co Ltd Secondary battery
WO2013018887A1 (en) * 2011-08-03 2013-02-07 日本ゼオン株式会社 Conductive adhesive composition for electrochemical element electrode, collector with adhesive layer, and electrochemical element electrode
WO2014046112A1 (en) * 2012-09-21 2014-03-27 古河スカイ株式会社 Current collector, electrode structure, and electricity storage component

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56133309A (en) * 1980-03-21 1981-10-19 Ugine Kuhlmann Polyfluorinated vinylidene copolymer and manufacture
JPH11149916A (en) * 1997-11-18 1999-06-02 Matsushita Electric Ind Co Ltd Organic electrolytic battery
JPH11288720A (en) * 1998-03-31 1999-10-19 Nippon Zeon Co Ltd Secondary battery binder composition, battery electrode slurry, battery electrode and secondary battery
JP2001155737A (en) * 1999-11-30 2001-06-08 Nippon Zeon Co Ltd Binder for electrode of lithium ion secondary cell and its utilization
JP2001283859A (en) * 2000-03-31 2001-10-12 Nippon Zeon Co Ltd Binder for electrode of lithium-ion secondary battery and its use

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56133309A (en) * 1980-03-21 1981-10-19 Ugine Kuhlmann Polyfluorinated vinylidene copolymer and manufacture
JPH11149916A (en) * 1997-11-18 1999-06-02 Matsushita Electric Ind Co Ltd Organic electrolytic battery
JPH11288720A (en) * 1998-03-31 1999-10-19 Nippon Zeon Co Ltd Secondary battery binder composition, battery electrode slurry, battery electrode and secondary battery
JP2001155737A (en) * 1999-11-30 2001-06-08 Nippon Zeon Co Ltd Binder for electrode of lithium ion secondary cell and its utilization
JP2001283859A (en) * 2000-03-31 2001-10-12 Nippon Zeon Co Ltd Binder for electrode of lithium-ion secondary battery and its use

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009538495A (en) * 2005-09-02 2009-11-05 エイ １２３ システムズ，インク． Nanocomposite electrodes and related equipment
WO2011070661A1 (en) * 2009-12-10 2011-06-16 トヨタ自動車株式会社 Process for producing electrode for battery
JPWO2011070661A1 (en) * 2009-12-10 2013-04-22 トヨタ自動車株式会社 Method for manufacturing battery electrode
JP5397711B2 (en) * 2009-12-10 2014-01-22 トヨタ自動車株式会社 Method for manufacturing battery electrode
US8877386B2 (en) 2009-12-10 2014-11-04 Toyota Jidosha Kabushiki Kaisha Battery electrode production method
JP2013016452A (en) * 2011-07-06 2013-01-24 Samsung Sdi Co Ltd Secondary battery
US10367205B2 (en) 2011-07-06 2019-07-30 Samsung Sdi Co., Ltd. Secondary battery
WO2013018887A1 (en) * 2011-08-03 2013-02-07 日本ゼオン株式会社 Conductive adhesive composition for electrochemical element electrode, collector with adhesive layer, and electrochemical element electrode
US10014528B2 (en) 2011-08-03 2018-07-03 Zeon Corporation Conductive adhesive composition for electrochemical element electrode, collector with adhesive layer, and electrochemical element electrode
WO2014046112A1 (en) * 2012-09-21 2014-03-27 古河スカイ株式会社 Current collector, electrode structure, and electricity storage component

Similar Documents

Publication Publication Date Title
US7351498B2 (en) Lithium ion polymer secondary battery its electrode and method for synthesizing polymer compound in binder used in adhesion layer thereof
JP3982221B2 (en) Lithium ion polymer secondary battery and method for synthesizing binder used for adhesion layer of battery
JP6149730B2 (en) Positive electrode for secondary battery, method for producing the same, slurry composition, and secondary battery
EP2858146B1 (en) Negative electrode for secondary batteries and method for producing same
AU2011274316B2 (en) Improved adhesion of active electrode materials to metal electrode substrates
WO2016152262A1 (en) All-solid secondary battery
WO2005029614A1 (en) Lithium ion secondary battery
JP2004095264A (en) Negative electrode for lithium ion secondary battery and lithium ion secondary battery manufactured by using the same
US20150303463A1 (en) Slurry composition for lithium ion secondary battery negative electrode, negative electrode for lithium ion secondary battery and method for producing the same, and lithium ion secondary battery
JPH09289023A (en) Electrode binder solution, electrode mixture, electrode structure, and battery
JP2002050360A (en) Lithium ion secondary battery electrode binder and its usage
JP2002117899A (en) Lithium polymer battery and its manufacturing process
JP6135258B2 (en) Secondary battery porous membrane slurry, secondary battery porous membrane, method for producing the same, and use
WO2017038067A1 (en) Composition for non-aqueous secondary cell functional layer, functional layer for non-aqueous secondary cell, and non-aqueous secondary cell
JPWO2016051674A1 (en) Adhesive composition for electrochemical device, adhesive layer for electrochemical device, and electrochemical device
WO2013154165A1 (en) Secondary battery electrode binder resin, secondary battery electrode composition, secondary battery electrode, and secondary battery
JP2013004229A (en) Binder for lithium secondary battery electrode, method for producing binder for lithium secondary battery electrode, lithium secondary battery electrode, and lithium secondary battery
JP2011249207A (en) Secondary battery electrode plate
JP2003257433A (en) Nonaqueous electrolyte secondary battery and binding agent
JP4942249B2 (en) Method for producing lithium ion secondary battery
JP2003173781A (en) Paint for adhesive layer as well as electrode for secondary battery and secondary battery using them
JP4325002B2 (en) Lithium battery
JP3726899B2 (en) Lithium ion polymer secondary battery
JP2004200011A (en) Cathode for lithium-ion secondary battery and lithium-ion secondary battery manufactured using the cathode
JP2003263987A (en) Binder for lithium ion polymer secondary cell

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050318

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20080822

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080916

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20081029

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20081216

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20090407