JPH11329443A - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JPH11329443A JPH11329443A JP10134019A JP13401998A JPH11329443A JP H11329443 A JPH11329443 A JP H11329443A JP 10134019 A JP10134019 A JP 10134019A JP 13401998 A JP13401998 A JP 13401998A JP H11329443 A JPH11329443 A JP H11329443A
- Authority
- JP
- Japan
- Prior art keywords
- weight
- positive electrode
- coating
- parts
- negative electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、リチウム二次電池
に関し、さらに詳しくは、充放電を繰り返した場合に電
池容量の減少が少ない、高容量のリチウム二次電池に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery, and more particularly, to a high-capacity lithium secondary battery that has a small decrease in battery capacity when charging and discharging are repeated.
【０００２】[0002]
【従来の技術】一般に、正極活物質にバインダーや溶剤
などを加え、分散、攪拌して調製した塗料を導電性基体
上に塗布、乾燥して正極活物質などを含有する塗膜を形
成したシート状の正極と、同様に負極活物質にバインダ
ーと溶剤などを加え、分散、攪拌して調製した塗料を導
電性基体上に塗布、乾燥して負極活物質などを含有する
塗膜を形成したシート状の負極とをセパレータを介して
対向させた積層電極体を、有機溶媒系の電解液と共に、
電池ケース内に封入して作製したリチウム二次電池は、
単位容量当たりのエネルギー密度や単位重量当たりのエ
ネルギー密度が高いという特徴を有している。2. Description of the Related Art In general, a sheet prepared by adding a binder or a solvent to a positive electrode active material, dispersing and stirring, coating a conductive substrate, and drying to form a coating film containing the positive electrode active material and the like. A positive electrode and a sheet in which a coating prepared by adding a binder and a solvent to the negative electrode active material, dispersing and stirring the same, coated on a conductive substrate, and dried to form a coating containing the negative electrode active material and the like A laminated electrode body in which a negative electrode in the form of a separator is opposed via a separator, together with an organic solvent-based electrolytic solution,
Lithium rechargeable batteries made by enclosing them in a battery case
It is characterized by high energy density per unit capacity and high energy density per unit weight.
【０００３】そして、上記シート状の正極やシート状の
負極などのシート状の電極に使用するバインダーとして
は、電池の作動中に電極塗膜構造が壊れることがないよ
うに電解液に対して溶解しにくい特性と、電極塗膜形成
用塗料を調製するために必要な溶剤可溶性を併せ持つこ
とが要求されることから、主成分モノマーとしてビニリ
デンフルオライドを含むポリビニリデンフルオライド系
ポリマー（以下、簡略化して、このポリマーを「ポリビ
ニリデンフルオライド系ポリマー」で表す）が好適なも
のとして用いられてきた。The binder used for the sheet-like electrode such as the above-mentioned sheet-like positive electrode and sheet-like negative electrode is dissolved in an electrolyte so that the electrode coating structure is not broken during the operation of the battery. Since it is required to have both the characteristics that are difficult to perform and the solvent solubility required for preparing the paint for forming the electrode coating film, polyvinylidene fluoride-based polymer containing vinylidene fluoride as the main component monomer Thus, this polymer is referred to as “polyvinylidene fluoride-based polymer”).
【０００４】しかしながら、上記ポリビニリデンフルオ
ライド系ポリマーは、導電性基体として一般的に用いら
れている金属箔との接着力が弱いため、バインダーとし
て該ポリビニリデンフルオライド系ポリマーを用いて形
成した電極塗膜は、導電性基体との接着力が弱く、従っ
て、上記塗膜を有する電極を用いて作製した電池は、充
放電を繰り返した場合に、電極塗膜と導電性基体との間
の電気的接触が悪化し、電極活物質の利用率が低下して
電池容量が減少するという問題があった。However, since the polyvinylidene fluoride-based polymer has a weak adhesive force to a metal foil generally used as a conductive substrate, an electrode formed using the polyvinylidene fluoride-based polymer as a binder is used. The coating film has a weak adhesive force to the conductive substrate, and therefore, the battery produced using the electrode having the above coating film has an electric charge between the electrode coating film and the conductive substrate when charging and discharging are repeated. There is a problem that the electrical contact deteriorates, the utilization rate of the electrode active material decreases, and the battery capacity decreases.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、上記のよう
な従来のリチウム二次電池における問題点を解決し、充
放電を繰り返した場合の電池容量の減少を抑制し、高容
量のリチウム二次電池を提供することを目的とする。SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional lithium secondary battery, suppresses a decrease in battery capacity when charging and discharging are repeated, and provides a high capacity lithium secondary battery. It is intended to provide a secondary battery.
【０００６】[0006]
【課題を解決するための手段】本発明は、上記課題を達
成するために種々検討を行った結果なされたものであ
り、導電性基体の少なくとも一方の面に少なくとも活物
質とバインダーを含有する塗膜を形成することによって
作製したシート状の正極とシート状の負極とをセパレー
タを介して対向させるリチウム二次電池において、上記
バインダーとして、主成分モノマーとしてビニリデンフ
ルオライドを含むポリビニリデンフルオライド系ポリマ
ー（すなわち、「ポリビニリデンフルオライド系ポリマ
ー」）と、セルロース系ポリマーとを併用することによ
って、充放電を繰り返した場合の電池容量の減少が少な
い、高容量のリチウム電池を提供したものである。Means for Solving the Problems The present invention has been made as a result of conducting various studies to achieve the above-mentioned object, and a coating containing at least an active material and a binder on at least one surface of a conductive substrate. In a lithium secondary battery in which a sheet-like positive electrode and a sheet-like negative electrode produced by forming a film are opposed via a separator, a polyvinylidene fluoride-based polymer containing vinylidene fluoride as a main component monomer as the binder By using a combination of a (polyvinylidene fluoride-based polymer) and a cellulose-based polymer, a high-capacity lithium battery with a small decrease in battery capacity when charge and discharge are repeated is provided.
【０００７】すなわち、本発明においては、電極塗膜の
バインダーが、ポリビニリデンフルオライド系ポリマー
とセルロース系ポリマーとで構成されるが、後者のセル
ロース系ポリマーがポリマー中に−ＯＨ基などを有する
ので、バインダーとしてポリビニリデンフルオライド系
ポリマーを単独で用いた場合に比べて、電極塗膜と導電
性基体との接着力が大きく、従って、充放電を繰り返し
た場合の電極塗膜と導電性基体との間の電気的接触の悪
化が抑制され、上記電気的接触の悪化に基づく電池容量
の減少を抑制することができる。That is, in the present invention, the binder of the electrode coating film is composed of a polyvinylidene fluoride-based polymer and a cellulose-based polymer. However, since the latter cellulose-based polymer has an —OH group or the like in the polymer. As compared with the case where a polyvinylidene fluoride-based polymer is used alone as a binder, the adhesive force between the electrode coating and the conductive substrate is large, and therefore, the electrode coating and the conductive substrate when repeated charge and discharge are performed. Of the battery is suppressed, and a decrease in the battery capacity due to the deterioration of the electrical contact can be suppressed.
【０００８】[0008]
【発明の実施の形態】本発明において、ポリビニリデン
フルオライド系ポリマーとセルロース系ポリマーとの混
合比率としては、ポリビニリデンフルオライド系ポリマ
ーが１０％〜９９．５重量％、特に２０〜９９重量％
で、セルロース系ポリマーが０．５重量％〜９０重量
％、特に１〜８０重量％であることが好ましい。セルロ
ース系ポリマーの比率が上記範囲より少ない場合は、電
極塗膜と導電性基体との接着力が小さくなり、充放電の
繰り返しによって電極塗膜と導電性基体との間の電気的
接触が悪化して、電池容量が減少するおそれがある。一
方、セルロース系ポリマーの比率が上記範囲より多い場
合は、電極塗膜と電解液との界面でのリチウムイオンの
伝導抵抗が増加して電池容量が低下するおそれがある。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the mixing ratio of a polyvinylidene fluoride-based polymer and a cellulose-based polymer is 10% to 99.5% by weight, particularly 20 to 99% by weight.
Preferably, the content of the cellulosic polymer is 0.5% to 90% by weight, particularly 1 to 80% by weight. If the ratio of the cellulosic polymer is less than the above range, the adhesive force between the electrode coating and the conductive substrate is reduced, and the electrical contact between the electrode coating and the conductive substrate is deteriorated by repeated charge and discharge. As a result, the battery capacity may be reduced. On the other hand, when the ratio of the cellulose-based polymer is larger than the above range, the conduction resistance of lithium ions at the interface between the electrode coating film and the electrolyte may increase, and the battery capacity may decrease.
【０００９】本発明において、バインダーを構成する一
方の構成成分であるポリビニリデンフルオライド系ポリ
マーは、主成分モノマーであるビニリデンフルオライド
を８０重量％以上含有する含フッ素モノマー群の重合体
が好ましい。上記の主成分モノマーであるビニリデンフ
ルオライドを８０重量％以上含有する含フッ素系モノマ
ー群としては、ビニリデンフルオライド単独、またはビ
ニリデンフルオイドと他のモノマーの少なくとも一種以
上との混合物が挙げられる。この他のモノマーとして
は、例えば、ビニルフルオライド、トリフルオロエチレ
ン、トリフルオロクロロエチレン、テトラフルオロエチ
レン、ヘキサフルオロプロピレン、フルオロアルキルビ
ニルエーテルなどを挙げることができる。本発明におい
て、上記のように含フッ素系モノマー群中のビニリデン
フルオライドが８０重量％以上であることを好ましいと
するのは、ビニリデンフルオライドが８０重量％より少
ない場合は、塗料の調製がしにくくなるおそれがあるた
めであり、含フッ素系モノマー群のすべてがビニリデン
フルオライドであってもよい。In the present invention, the polyvinylidene fluoride-based polymer as one of the constituent components of the binder is preferably a polymer of a fluorine-containing monomer group containing at least 80% by weight of vinylidene fluoride as a main component monomer. Examples of the fluorine-containing monomer group containing at least 80% by weight of vinylidene fluoride as the main component monomer include vinylidene fluoride alone or a mixture of vinylidene fluoride and at least one or more other monomers. Examples of the other monomer include vinyl fluoride, trifluoroethylene, trifluorochloroethylene, tetrafluoroethylene, hexafluoropropylene, and fluoroalkyl vinyl ether. In the present invention, as described above, it is preferable that the vinylidene fluoride in the fluorine-containing monomer group is 80% by weight or more. When the vinylidene fluoride is less than 80% by weight, the paint is prepared. This is because the fluorinated monomer group may be vinylidene fluoride.
【００１０】また、本発明において、バインダーを構成
する他方の構成成分であるセルロース系ポリマーとして
は、ポリビニリデンフルオライド系ポリマーが溶解する
溶剤に溶解するものが好ましく、そのような観点から、
例えば、メチルセルロース、エチルセルロース、ヒドロ
キシプロピルセルロース、ヒドロキシエチルメチルセル
ロース、ヒドロキシプロピルメチルセルロースなどが挙
げられる。In the present invention, the cellulose-based polymer as the other component constituting the binder is preferably a polymer soluble in a solvent in which the polyvinylidene fluoride-based polymer is soluble.
For example, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose and the like can be mentioned.
【００１１】本発明において、バインダーは電極塗膜中
において０．２〜２０重量％、特に０．５〜１０重量％
であることが好ましい。バインダーの含有量が上記範囲
より少ない場合は、電極塗膜の機械的強度が低下して、
電極塗膜が導電性基体から剥離するおそれがあり、ま
た、バインダーの含有量が上記範囲より多い場合は、電
極塗膜中の活物質が減少して電池容量が低下するおそれ
がある。In the present invention, the binder is 0.2 to 20% by weight, particularly 0.5 to 10% by weight in the electrode coating film.
It is preferred that If the content of the binder is less than the above range, the mechanical strength of the electrode coating decreases,
The electrode coating film may be peeled off from the conductive substrate, and when the content of the binder is more than the above range, the active material in the electrode coating film may be reduced and the battery capacity may be reduced.
【００１２】本発明のポリビニリデンフルオライド系ポ
リマーとセルロース系ポリマーとからなるバインダー
は、正極、負極のうちいずれの電極に使用しても良く、
また、正極、負極の両方に使用しても良い。The binder comprising the polyvinylidene fluoride-based polymer and the cellulose-based polymer of the present invention may be used for any one of a positive electrode and a negative electrode.
Moreover, you may use for both a positive electrode and a negative electrode.
【００１３】本発明において、正極活物質としては、例
えば、リチウムニッケル酸化物、リチウムコバルト酸化
物、リチウムマンガン酸化物（これらは、通常、ＬｉＮ
ｉＯ 2 、ＬｉＣｏＯ2 、ＬｉＭｎ2 Ｏ4 で表されるが、
ＬｉとＮｉの比、ＬｉとＭｎとの比は化学量論組成から
ずれている場合が多い）などのリチウム含有複合金属酸
化物が単独でまたは２種以上の混合物として、あるいは
それらの固溶体として用いられる。In the present invention, examples of the positive electrode active material include:
For example, lithium nickel oxide, lithium cobalt oxide
Material, lithium manganese oxide (these are usually LiN
iO Two, LiCoOTwo, LiMnTwoOFourIs represented by
The ratio of Li to Ni and the ratio of Li to Mn are determined from the stoichiometric composition.
Lithium-containing composite metal acids such as
Compound alone or as a mixture of two or more, or
Used as their solid solution.
【００１４】そして、正極の作製にあたっては、必要に
応じ、上記正極活物質に鱗片状黒鉛、カーボンブラック
などの電子伝導助剤を添加することができる。In preparing the positive electrode, an electron conduction aid such as flaky graphite and carbon black can be added to the positive electrode active material, if necessary.
【００１５】正極は、例えば、上記正極活物質を含み、
必要に応じて、鱗片状黒鉛、カーボンブラックなどの電
子伝導助剤を含み、さらにバインダーを含む塗料を導電
性基体上に塗布し、乾燥して、導電性基体の少なくとも
一方の面に少なくとも正極活物質とバインダーを含有す
る塗膜を形成する工程を経て作製される。なお、上記塗
料の調製に当たって、バインダーはあらかじめ溶剤に溶
解させた溶液として用い、上記正極活物質などの固体粒
子と混合して塗料を調製するようにしてもよい。The positive electrode contains, for example, the above-mentioned positive electrode active material,
If necessary, a paint containing an electron conduction aid such as flaky graphite and carbon black, and further containing a binder is applied on the conductive substrate, and dried, so that at least one surface of the conductive substrate has at least a positive electrode active material. It is produced through a step of forming a coating film containing a substance and a binder. In preparing the coating material, the binder may be used as a solution previously dissolved in a solvent, and mixed with solid particles such as the positive electrode active material to prepare the coating material.
【００１６】また、本発明において、負極活物質として
は、例えば、リチウム金属またはリチウム含有化合物が
用いられるが、そのリチウム含有化合物としてはリチウ
ム合金とそれ以外のものがある。上記リチウム合金とし
ては、例えば、リチウム−アルミニウム、リチウム−
鉛、リチウム−ビスマス、リチウム−インジウム、リチ
ウム−ガリウム、リチウム−インジウム−ガリウムなど
のリチウムと他の金属との合金が挙げられる。リチウム
合金以外のリチウム含有化合物としては、例えば、乱層
構造を有する炭素材料、黒鉛などが挙げられる。これら
は製造時にはリチウムを含んでいないものもあるが、負
極活物質として作用するときには、化学的手段、電気化
学的手段によりリチウムを含有した状態になる。In the present invention, as the negative electrode active material, for example, lithium metal or a lithium-containing compound is used. As the lithium-containing compound, there are a lithium alloy and others. Examples of the lithium alloy include lithium-aluminum, lithium-
Examples include alloys of lithium and other metals such as lead, lithium-bismuth, lithium-indium, lithium-gallium, and lithium-indium-gallium. Examples of the lithium-containing compound other than the lithium alloy include a carbon material having a turbostratic structure, graphite, and the like. Some of them do not contain lithium at the time of manufacture, but when they act as a negative electrode active material, they are in a state containing lithium by chemical means or electrochemical means.
【００１７】負極は、例えば、上記負極活物質に、必要
に応じて、例えば、鱗片状黒鉛、カーボンブラックなど
の電子伝導助剤を添加し、さらにバインダーと溶剤を加
え、混合して塗料を調製し、その塗料を導電性基体上に
塗布し、乾燥して、導電性基体の少なくとも一方の面に
少なくとも負極活物質とバインダーを含有する塗膜を形
成する工程を経て作製される。なお、上記塗料の調製に
あたっては、バインダーはあらかじめ溶剤に溶解させ、
バインダー溶液として負極活物質などと混合して塗料を
調製するようにしてもよい。For the negative electrode, for example, a paint is prepared by adding an electron conduction aid such as flake graphite and carbon black to the negative electrode active material, if necessary, further adding a binder and a solvent, and mixing. Then, the paint is applied on a conductive substrate and dried to form a coating film containing at least a negative electrode active material and a binder on at least one surface of the conductive substrate. In preparing the paint, the binder was dissolved in a solvent in advance,
A paint may be prepared by mixing with a negative electrode active material or the like as a binder solution.
【００１８】本発明において、上記ポリビニリデンフル
オライド系ポリマーとセルロース系ポリマーとをバイン
ダーとして用いる塗膜の形成用に使用する塗料の溶剤と
しては、ビニリデンフルオライド系ポリマーとセルロー
ス系ポリマーを共に溶解させるような溶剤を使用するこ
とが好ましく、そのような溶剤としては、例えば、Ｎ−
メチルピロリドン、ジメチルアセトアミド、ジメチルホ
ルムアミド、テトラヒドロフランなどが挙げられ、それ
らは単独でまたは２種以上混合して用いることができ
る。In the present invention, as a solvent for a paint used for forming a coating film using the polyvinylidene fluoride-based polymer and the cellulose-based polymer as a binder, both the vinylidene fluoride-based polymer and the cellulose-based polymer are dissolved. It is preferable to use such a solvent. As such a solvent, for example, N-
Methylpyrrolidone, dimethylacetamide, dimethylformamide, tetrahydrofuran and the like can be mentioned, and these can be used alone or in combination of two or more.
【００１９】上記塗料を導電性基体に塗布する際の塗布
方法としては、例えば、押出しコータ、リバースローラ
ー、ドクターブレード、アプリケーターなどをはじめ、
各種の塗布方法を採用することができる。Examples of the method of applying the above-mentioned paint to the conductive substrate include an extrusion coater, a reverse roller, a doctor blade, and an applicator.
Various coating methods can be adopted.
【００２０】本発明において、正極、負極などの電極の
導電性基体としては、例えば、アルミニウム、ステンレ
ス鋼、チタン、銅などの金属性導電材料を網、パンチド
メタル、フォームメタルや、板状に加工した箔などが用
いられる。In the present invention, as a conductive substrate for electrodes such as a positive electrode and a negative electrode, for example, a metallic conductive material such as aluminum, stainless steel, titanium, or copper may be used in the form of a net, punched metal, foam metal, or plate. A processed foil or the like is used.
【００２１】電解液としては、例えば、１，２−ジメト
キシエタン、１，２−ジエトキシエタン、プロピレンカ
ーボネート、エチレンカーボネート、γ−ブチロラクト
ン、テトラヒドロフラン、１，３−ジオキソラン、ジエ
チルカーボネート、ジメチルカーボネート、エチルメチ
ルカーボネートなどの単独または２種以上の混合溶媒
に、例えば、ＬｉＣＦ3 ＳＯ3 、ＬｉＣ4 Ｆ9 ＳＯ3 、
ＬｉＣｌＯ4 、ＬｉＰＦ 6 、ＬｉＢＦ4 などの電解質を
単独でまたは２種以上溶解させて調製した有機溶媒系の
電解液が用いられる。As the electrolytic solution, for example, 1,2-dimethoate
Xiethane, 1,2-diethoxyethane, propylene
-Carbonate, ethylene carbonate, γ-butyrolact
, Tetrahydrofuran, 1,3-dioxolan, die
Chill carbonate, dimethyl carbonate, ethyl methyl
Single or mixed solvent of two or more such as carbonate
For example, LiCFThreeSOThree, LiCFourF9SOThree,
LiClOFour, LiPF 6, LiBFFourSuch as electrolyte
Organic solvent system prepared alone or by dissolving two or more
An electrolyte is used.
【００２２】セパレータとしては、例えば、厚さ１０〜
５０μｍで、開孔率３０〜７０％の微多孔性ポリエチレ
ンフィルムまたは微多孔性ポリプロピレンフィルムなど
が好適に用いられる。As the separator, for example, a thickness of 10 to 10
A microporous polyethylene film or a microporous polypropylene film having a pore size of 50 μm and a porosity of 30 to 70% is preferably used.
【００２３】電池は、例えば、上記のようにして作製さ
れるシート状の正極とシート状の負極との間にセパレー
タを介在させて渦巻状に巻回して作製した渦巻状巻回構
造の電極体を、ニッケルメッキを施した鉄やステンレス
鋼製の電池ケース内に挿入し、電解液を注入し、封口す
る工程を経て作製される。また、上記電池には、通常、
電池内部に発生したガスをある一定圧力まで上昇した段
階で電池外部に排出して、電池の高圧下での破裂を防止
するための防爆機構が取り入れられる。The battery is, for example, a spirally wound electrode body manufactured by spirally winding a sheet-shaped positive electrode and a sheet-shaped negative electrode manufactured as described above with a separator interposed therebetween. Is inserted into a nickel-plated iron or stainless steel battery case, injected with an electrolyte, and sealed. In addition, the battery usually includes
An explosion-proof mechanism is introduced to prevent gas from exploding under high pressure by discharging the gas generated inside the battery to a certain pressure when the gas rises to a certain level.
【００２４】[0024]
【実施例】つぎに、本発明の実施例について説明する。
ただし、本発明はそれらの実施例のみに限定されるもの
ではない。なお、以下の実施例などにおいて、濃度など
を示す％は重量％である。Next, an embodiment of the present invention will be described.
However, the present invention is not limited to only these examples. In the examples below,% indicating the concentration and the like is% by weight.
【００２５】実施例１ （１）正極の作製 正極の作製を、正極活物質として用いるリチウムニッケ
ル酸化物の合成、塗膜の形成の順に説明する。Example 1 (1) Preparation of Positive Electrode The preparation of a positive electrode will be described in the order of synthesis of lithium nickel oxide used as a positive electrode active material and formation of a coating film.
【００２６】リチウムニッケル酸化物の合成 水酸化リチウム（ＬｉＯＨ・Ｈ2 Ｏ）と酸化ニッケル
（Ｎｉ2 Ｏ3 ）とを熱処理してリチウムニッケル酸化物
を合成した。上記の合成は以下のように行った。Synthesis of Lithium Nickel Oxide Lithium hydroxide (LiOH.H 2 O) and nickel oxide (Ni 2 O 3 ) were heat-treated to synthesize lithium nickel oxide. The above synthesis was performed as follows.
【００２７】水酸化リチウムと酸化ニッケルとをＬｉ／
Ｎｉ＝１／１．０５（モル比）の割合になるように秤量
した後、メノウ製の乳鉢で粉砕しつつ混合した。これを
酸素（Ｏ2 ）気流中において５００℃で２時間予備加熱
した後、昇温速度５０℃／ｈ以下で７００℃で２０時間
加熱して焼成することによってリチウムニッケル酸化物
を合成した。なお、合成したリチウムニッケル酸化物は
水分に対して弱いため、粉砕などの取扱いは、アルゴン
ガス雰囲気中で行った。Lithium hydroxide and nickel oxide are converted to Li /
After weighing so that Ni = 1 / 1.05 (molar ratio), the mixture was pulverized and mixed in an agate mortar. This was preliminarily heated at 500 ° C. for 2 hours in an oxygen (O 2 ) stream, and then heated at 700 ° C. for 20 hours at a heating rate of 50 ° C./h or less to synthesize lithium nickel oxide. Since the synthesized lithium nickel oxide is weak against moisture, handling such as pulverization was performed in an argon gas atmosphere.
【００２８】塗膜の形成 まず、上記のようにして合成したリチウムニッケル酸化
物と、電子伝導助剤としての鱗片状黒鉛、バインダーを
構成するポリビニリデンフルオライド系ポリマーとして
のポリビニリデンフルオライドと、セルロース系ポリマ
ーとしてのヒドロキシプロピルセルロースを用い、それ
らと溶剤としてのＮ−メチルピロリドンを下記の組成で
含む正極塗膜形成用塗料を調製した。First, lithium nickel oxide synthesized as described above, flaky graphite as an electron conduction aid, polyvinylidene fluoride as a polyvinylidene fluoride-based polymer constituting a binder, A coating material for forming a positive electrode coating film containing hydroxypropyl cellulose as a cellulosic polymer and N-methylpyrrolidone as a solvent with the following composition was prepared.
【００２９】正極塗膜形成用塗料の組成 リチウムニッケル酸化物 ９０重量部 鱗片状黒鉛 ６重量部 ポリビニリデンフルオライド ３．２重量部 ヒドロキシプロピルセルロース ０．８重量部 Ｎ−メチルピロリドン ４５重量部Composition of coating material for forming positive electrode coating film Lithium nickel oxide 90 parts by weight Flake graphite 6 parts by weight Polyvinylidene fluoride 3.2 parts by weight Hydroxypropylcellulose 0.8 parts by weight N-methylpyrrolidone 45 parts by weight
【００３０】上記塗料の調製は次に示すように行った。
まず、Ｎ−メチルピロリドンにポリビニリデンフルオラ
イドとヒドロキシプロピルセルロースを溶解してバイン
ダー溶液を調製し、このバインダー溶液に正極活物質の
リチウムニッケル酸化物と電子伝導助剤としての鱗片状
黒鉛を加え、混合することによって塗料を調製した。The preparation of the paint was carried out as follows.
First, polyvinylidene fluoride and hydroxypropyl cellulose are dissolved in N-methylpyrrolidone to prepare a binder solution, and lithium nickel oxide of the positive electrode active material and flaky graphite as an electron conduction aid are added to the binder solution, A paint was prepared by mixing.
【００３１】得られた塗料を導電性基体としての厚さ２
０μｍのアルミニウム箔上にアプリケータを用いて塗布
し、１００〜１２０℃で乾燥して正極活物質やバインダ
ーなどを含有する塗膜を形成した。同様に、アルミニウ
ム箔の裏面側にも上記塗料を塗布し、１００℃で８時間
真空乾燥して塗膜を形成した。そして、得られた電極体
をロールプレスして、片面の塗膜厚みが８０μｍのシー
ト状の正極を作製した。The obtained paint is used as a conductive substrate having a thickness of 2
It was applied on a 0 μm aluminum foil using an applicator, and dried at 100 to 120 ° C. to form a coating film containing a positive electrode active material, a binder, and the like. Similarly, the above-mentioned paint was applied to the back surface side of the aluminum foil, and vacuum-dried at 100 ° C. for 8 hours to form a coating film. Then, the obtained electrode body was roll-pressed to produce a sheet-like positive electrode having a coating thickness of 80 μm on one side.
【００３２】（２）負極の作製 負極活物質として人造黒鉛（２８００℃で合成）を用
い、バインダーとして正極塗膜形成用塗料に用いたもの
と同様のポリビニリデンフルオライド系ポリマーとセル
ロース系ポリマーとを用い、それらを下記の割合で含む
負極塗膜形成用塗料を調製した。(2) Preparation of Negative Electrode As a negative electrode active material, artificial graphite (synthesized at 2800 ° C.) was used, and as a binder, the same polyvinylidene fluoride-based polymer and cellulose-based polymer as those used in the paint for forming a positive electrode coating film were used. Was used to prepare a paint for forming a negative electrode coating film, which contained them at the following ratio.
【００３３】負極塗膜形成用塗料の組成 人造黒鉛 ９０重量部 ポリビニリデンフルオライド ８重量部 ヒドロキシプロピルセルロース ２重量部 Ｎ−メチルピロリドン ８０重量部Composition of paint for forming negative electrode coating film 90 parts by weight of artificial graphite 8 parts by weight of polyvinylidene fluoride 2 parts by weight of hydroxypropyl cellulose 80 parts by weight of N-methylpyrrolidone
【００３４】得られた塗料を導電性基体としての厚さ１
８μｍの銅箔上にアプリケータを用いて塗布し、１００
〜１２０℃で乾燥して負極活物質やバインダーを含有す
る塗膜を形成した。同様に、銅箔の裏面側にも上記塗料
を塗布し、１００℃で８時間真空乾燥して塗膜を形成し
た。そして、この電極体をロールプレスして、片面の塗
膜厚みが８０μｍのシート状の負極を作製した。なお、
正極と負極は両者の活物質の重量比が２：１になるよう
に塗膜密度を調整した。The obtained paint was used as a conductive substrate to a thickness of 1
Apply on an 8 μm copper foil using an applicator,
It dried at -120 degreeC, and formed the coating film containing a negative electrode active material and a binder. Similarly, the paint was applied to the back side of the copper foil and vacuum dried at 100 ° C. for 8 hours to form a coating film. Then, the electrode body was roll-pressed to produce a sheet-shaped negative electrode having a coating thickness on one side of 80 μm. In addition,
The coating density of the positive electrode and the negative electrode was adjusted so that the weight ratio of both active materials was 2: 1.
【００３５】（３）電解液の調製 エチレンカーボネートとエチルメチルカーボネートとの
体積比１：１の混合溶媒にＬｉＰＦ6 を１ｍｏｌ／ｌ溶
解して有機溶媒系の電解液を調製した。(3) Preparation of Electrolyte Solution 1 mol / l of LiPF 6 was dissolved in a mixed solvent of ethylene carbonate and ethyl methyl carbonate at a volume ratio of 1: 1 to prepare an organic solvent-based electrolyte solution.
【００３６】（４）筒形電池の組立て 上記シート状の正極を幅２８ｍｍ×長さ２２０ｍｍの帯
状に切断し、シート状の負極を幅３０ｍｍ×長さ２６０
ｍｍの帯状に切断した。そして、それぞれの電極の一方
の端部の塗膜の一部を剥がして、金属箔を露出させた部
分に、アルミニウム製のリード体を抵抗溶接し、厚み２
５μｍで開孔率５０％の微多孔性ポリエチレンフィルム
からなる帯状セパレータを上記シート状の正極とシート
状の負極の間に介在させ、渦巻状に巻回して渦巻状電極
体を作製し、その渦巻状電極体をステンレス鋼製の電池
ケースに挿入した。(4) Assembly of cylindrical battery The above sheet-shaped positive electrode was cut into a strip having a width of 28 mm and a length of 220 mm, and the sheet-shaped negative electrode was cut into a width of 30 mm and a length of 260 mm.
mm. Then, a part of the coating film at one end of each electrode was peeled off, and a lead made of aluminum was resistance-welded to a portion where the metal foil was exposed, to obtain a thickness of 2 mm.
A strip separator made of a microporous polyethylene film having a pore ratio of 5 μm and a porosity of 50% is interposed between the sheet-shaped positive electrode and the sheet-shaped negative electrode, and spirally wound to produce a spiral electrode body. The electrode body was inserted into a stainless steel battery case.
【００３７】そして、負極側のリード体の先端を絶縁体
を貫通させて電池ケースの底部に溶接し、さらに、電池
ケースの開口部に絶縁体を挿入し、溝を形成した後、封
口板と正極側のリード体とを溶接した。そして、このよ
うな工程を経て作製された電極などを内填する缶体を６
０℃で１０時間真空乾燥した後、乾燥雰囲気中で電解液
２ｍｌを注入後、封口して図１に示す筒形のＲ５形リチ
ウム二次電池（外径：１４．９５ｍｍ、高さ：３９．７
ｍｍ）を作製した。Then, the tip of the lead body on the negative electrode side is welded to the bottom of the battery case by penetrating the insulator, and further, the insulator is inserted into the opening of the battery case to form a groove. The lead body on the positive electrode side was welded. Then, the can body into which the electrodes and the like manufactured through these steps are filled is 6
After vacuum drying at 0 ° C. for 10 hours, 2 ml of an electrolytic solution was injected in a dry atmosphere, sealed, and sealed to form a cylindrical R5 lithium secondary battery shown in FIG. 1 (outer diameter: 14.95 mm, height: 39.80 mm). 7
mm).
【００３８】図１に示す電池について説明すると、１は
前記の正極で、２は負極である。ただし、図１では、繁
雑化を避けるため、正極１や負極２の作製にあたって使
用した導電性基体としての金属箔などは図示していな
い。そして、これらの正極１と負極２はセパレータ３を
介して渦巻状に巻回され、渦巻状巻回構造の電極体とし
て電解液４と共に電池ケース５内に収容されている。Referring to the battery shown in FIG. 1, 1 is the positive electrode and 2 is the negative electrode. However, FIG. 1 does not show a metal foil or the like as a conductive substrate used in manufacturing the positive electrode 1 or the negative electrode 2 in order to avoid complication. The positive electrode 1 and the negative electrode 2 are spirally wound via a separator 3 and housed in a battery case 5 together with an electrolyte 4 as an electrode body having a spirally wound structure.
【００３９】電池ケース５はステンレス鋼製で、負極端
子を兼ねており、この電池ケース５の底部には上記渦巻
状巻回構造の電極体の挿入に先立って、ポリプロピレン
製の絶縁体６が配置されている。封口板７はアルミニウ
ム製で、円板状をしていて、中央部に薄肉部７ａを設
け、かつ上記薄肉部７ａの周囲に電池内圧を防爆弁９に
作用させるための圧力導入口７ｂとしての孔が設けられ
ている。そして、この薄肉部７ａの上面に防爆弁９の突
出部９ａが溶接され、溶接部分１１を構成している。な
お、上記の封口板７に設けた薄肉部７ａや防爆弁９の突
出部９ａなどは、図面上での理解がしやすいように、切
断面のみを図示しており、切断面後方の輪郭線は図示を
省略している。また、封口板７の薄肉部７ａと防爆弁９
の突出部９ａとの溶接部分１１も、図面上での理解が容
易なように、実際よりは誇張した状態に図示している。The battery case 5 is made of stainless steel and also serves as a negative electrode terminal. A polypropylene insulator 6 is arranged at the bottom of the battery case 5 before inserting the spirally wound electrode body. Have been. The sealing plate 7 is made of aluminum, has a disk shape, is provided with a thin portion 7a at the center, and serves as a pressure introduction port 7b around the thin portion 7a for applying the internal pressure of the battery to the explosion-proof valve 9. A hole is provided. The projection 9a of the explosion-proof valve 9 is welded to the upper surface of the thin portion 7a to form a welded portion 11. In addition, the thin portion 7a provided on the sealing plate 7 and the protruding portion 9a of the explosion-proof valve 9 are illustrated only in a cut plane so as to be easily understood in the drawings, and a contour line behind the cut plane is shown. Is not shown. Further, the thin portion 7a of the sealing plate 7 and the explosion-proof valve 9
Also, the welded portion 11 with the projection 9a is shown in an exaggerated state in order to facilitate understanding on the drawings.
【００４０】端子板８は、圧延鋼製で表面にニッケルメ
ッキが施され、周縁部が鍔状になった帽子状をしてお
り、この端子板８にはガス排出孔８ａが設けられてい
る。防爆弁９は、アルミニウム製で、円板状をしてお
り、その中央部には発電要素側（図１では、下側）に先
端部を有する突出部９ａが設けられ、その突出部９ａの
下面が、前記したように、封口板７の薄肉部７ａの上面
に溶接され、溶接部分１１を構成している。絶縁パッキ
ング１０は、ポリプロピレン製で、環状をしており、封
口板７の周縁部の上部に配置され、その上部に防爆弁９
が配置していて、封口板７と防爆弁９とを絶縁するとと
もに、両者の間から電解液が漏れないように両者の間隙
を封止している。環状ガスケット１２はポリプロピレン
製で、リード体１３はアルミニウム製で、前記封口板７
と正極１とを接続し、渦巻状巻回構造の電極体の上部に
は絶縁体１４が配置され、負極２と電池ケース５の底部
とはニッケル製のリード体１５で接続されている。The terminal plate 8 is made of rolled steel, nickel-plated on its surface, and has a hat-like shape with a peripheral edge formed in a flange shape. The terminal plate 8 is provided with a gas discharge hole 8a. . The explosion-proof valve 9 is made of aluminum and is in the shape of a disk, and a central portion is provided with a projecting portion 9a having a tip on the power generation element side (the lower side in FIG. 1). As described above, the lower surface is welded to the upper surface of the thin portion 7a of the sealing plate 7 to form a welded portion 11. The insulating packing 10 is made of polypropylene and has an annular shape. The insulating packing 10 is disposed above the peripheral edge of the sealing plate 7 and has an explosion-proof valve 9
Are arranged to insulate the sealing plate 7 from the explosion-proof valve 9 and seal the gap between the two so that the electrolyte does not leak from between them. The annular gasket 12 is made of polypropylene, and the lead body 13 is made of aluminum.
And the positive electrode 1 are connected. An insulator 14 is disposed on the top of the spirally wound electrode body, and the negative electrode 2 and the bottom of the battery case 5 are connected by a nickel lead 15.
【００４１】前記のように、電池ケース５の底部には絶
縁体６が配置され、前記正極１、負極２およびセパレー
タ３からなる渦巻状巻回構造の電極体や、電解液４、渦
巻状巻回構造の電極体上部の絶縁体１４などは、この電
池ケース５内に収容され、それらの収容後、電池ケース
５の開口端近傍部分に底部が内方に突出した環状の溝が
形成される。そして、上記電池ケース５の開口部に、封
口板７、絶縁パッキング１０、防爆弁９が挿入された環
状ガスケット１２を入れ、さらにその上から端子板８を
挿入し、電池ケース５の溝から先の部分を内方に締め付
けることによって、電池ケース５の開口部が封口されて
いる。ただし、上記のような電池組立にあたっては、前
記のように、あらかじめ負極２と電池ケース５とをリー
ド体１５で接続し、正極１と封口板７とをリード体１３
で接続しておくことが好ましい。As described above, the insulator 6 is disposed at the bottom of the battery case 5. The spirally wound electrode body including the positive electrode 1, the negative electrode 2, and the separator 3, the electrolytic solution 4, and the spirally wound electrode The insulator 14 and the like at the top of the electrode structure having a round structure are accommodated in the battery case 5, and after these are accommodated, an annular groove having a bottom portion projecting inward is formed in the vicinity of the open end of the battery case 5. . Then, the sealing plate 7, the insulating packing 10, and the annular gasket 12 into which the explosion-proof valve 9 is inserted are inserted into the opening of the battery case 5, and the terminal plate 8 is further inserted therefrom. Is tightened inward to seal the opening of the battery case 5. However, in assembling the battery as described above, as described above, the negative electrode 2 and the battery case 5 are connected in advance with the lead 15, and the positive electrode 1 and the sealing plate 7 are connected with the lead 13.
It is preferable to connect them.
【００４２】上記のようにして組み立てられた電池にお
いては、封口板７の薄肉部７ａと防爆弁９の突出部９ａ
とが溶接部分１１で接触し、防爆弁９の周縁部と端子板
８の周縁部とが接触し、正極１と封口板７とは正極側の
リード体１３で接続されているので、正極１と端子板８
とはリード体１３、封口板７、防爆弁９およびそれらの
溶接部分１１によって電気的接続が得られ、電路として
正常に機能する。In the battery assembled as described above, the thin portion 7a of the sealing plate 7 and the projection 9a of the explosion-proof valve 9 are provided.
Contact at the welded portion 11, the peripheral portion of the explosion-proof valve 9 and the peripheral portion of the terminal plate 8 come into contact, and the positive electrode 1 and the sealing plate 7 are connected by the lead 13 on the positive electrode side. And terminal plate 8
The electrical connection is obtained by the lead body 13, the sealing plate 7, the explosion-proof valve 9 and the welded portion 11 thereof, and the lead body normally functions as an electric circuit.
【００４３】そして、電池に異常事態が起こり、電池内
部にガスが発生して電池の内圧が上昇した場合には、そ
の内圧上昇により、防爆弁９の中央部が内圧方向（図１
では、上側の方向）に変形し、それに伴って溶接部分１
１で一体化されている薄肉部７ａに剪断力が働いて、該
薄肉部７ａが破断するか、または防爆弁９の突出部９ａ
と封口板７の薄肉部７ａとの溶接部分１１が剥離し、そ
れによって、正極１と端子板８との電気的接続が消失し
て、電流が遮断されるようになる。その結果、電池反応
が進行しなくなるので、過充電時や短絡時でも、充電電
流や短絡電流による電池の温度上昇や内圧上昇がそれ以
上進行しなくなって、電池の発火や破裂を防止できるよ
うに設計されている。When an abnormal situation occurs in the battery and gas is generated inside the battery and the internal pressure of the battery rises, the internal pressure rises and the central part of the explosion-proof valve 9 moves in the direction of the internal pressure (FIG. 1).
Then, it is deformed in the upper direction)
The shearing force acts on the thin portion 7a integrated at 1 and the thin portion 7a is broken or the projection 9a of the explosion-proof valve 9 is formed.
And the thin portion 7a of the sealing plate 7 is peeled off, whereby the electrical connection between the positive electrode 1 and the terminal plate 8 is lost and the current is cut off. As a result, the battery reaction does not proceed, so that even during overcharge or short circuit, the battery temperature rise and internal pressure rise due to the charging current and short circuit current do not progress further, so that ignition and rupture of the battery can be prevented. Designed.
【００４４】なお、上記防爆弁９には薄肉部９ｂが設け
られており、たとえば、充電が極度に進行にして電解液
や活物質などの発電要素が分解し、大量のガスが発生し
た場合は、防爆弁９が変形して、防爆弁９の突出部９ａ
と封口板７の薄肉部７ａとの溶接部分１１が剥離した
後、この防爆弁９に設けた薄肉部９ｂが開裂してガスを
端子板８のガス排出孔８ａから電池外部に排出させて電
池の破裂を防止することができるように設計されてい
る。The explosion-proof valve 9 is provided with a thin portion 9b. For example, when charging proceeds extremely and power generation elements such as an electrolyte and an active material are decomposed and a large amount of gas is generated. The explosion-proof valve 9 is deformed, and the protrusion 9a of the explosion-proof valve 9 is deformed.
After the welded portion 11 of the sealing plate 7 and the thin portion 7a of the sealing plate 7 is peeled off, the thin portion 9b provided on the explosion-proof valve 9 is torn, and gas is discharged from the gas discharge hole 8a of the terminal plate 8 to the outside of the battery. It is designed to be able to prevent the rupture.
【００４５】実施例２ 実施例１の正極塗膜形成用塗料の組成中のポリビニリデ
ンフルオライド３．２重量部を３．８重量部に変更し、
正極塗膜形成用塗料の組成中のヒドロキシプロピルセル
ロース０．８重量部を０．２重量部に変更し、正極塗膜
形成用塗料の組成中のＮ−メチルピロリドン４５重量部
を４３重量部に変更し、負極塗膜形成用塗料の組成中の
ポリビニリデンフルオライド８重量部を９．５重量部に
変更し、負極塗膜形成用塗料の組成中のヒドロキシプロ
ピルセルロース２重量部を０．５重量部に変更し、負極
塗膜形成用塗料の組成中のＮ−メチルピロリドン８０重
量部を７５重量部に変更したほかは、実施例１と同様に
Ｒ５形のリチウム二次電池を作製した。Example 2 3.2 parts by weight of polyvinylidene fluoride in the composition of the coating material for forming a positive electrode coating film of Example 1 was changed to 3.8 parts by weight.
0.8 parts by weight of hydroxypropyl cellulose in the composition of the coating for forming a positive electrode coating was changed to 0.2 parts by weight, and 45 parts by weight of N-methylpyrrolidone in the composition of the coating for forming a positive electrode coating was changed to 43 parts by weight. 8 parts by weight of polyvinylidene fluoride in the composition of the coating for forming a negative electrode coating were changed to 9.5 parts by weight, and 2 parts by weight of hydroxypropyl cellulose in the composition of the coating for forming a negative electrode coating were changed to 0.5 part by weight. R5 type lithium secondary battery was produced in the same manner as in Example 1, except that the composition was changed to 80 parts by weight of N-methylpyrrolidone and 75 parts by weight in the composition of the coating material for forming a negative electrode coating film.
【００４６】実施例３ 実施例１の正極塗膜形成用塗料の組成中のポリビニリデ
ンフルオライド３．２重量部を３．９２重量部に変更
し、正極塗膜形成用塗料の組成中のヒドロキシプロピル
セルロース０．８重量部を０．０８重量部に変更し、正
極塗膜形成用塗料の組成中のＮ−メチルピロリドン４５
重量部を４０重量部に変更し、負極塗膜形成用塗料の組
成中のポリビニリデンフルオライド８重量部を９．８重
量部に変更し、負極塗膜形成用塗料の組成中のヒドロキ
シプロピルセルロース２重量部を０．２重量部に変更
し、負極塗膜形成用塗料の組成中のＮ−メチルピロリド
ン８０重量部を７４重量部に変更したほかは、実施例１
と同様にＲ５形のリチウム二次電池を作製した。Example 3 The composition of the coating for forming a positive electrode coating film of Example 1 was changed from 3.2 parts by weight of polyvinylidene fluoride to 3.92 parts by weight of the coating composition for forming a positive electrode coating film. 0.8 parts by weight of propylcellulose was changed to 0.08 parts by weight, and N-methylpyrrolidone 45 in the composition of the paint for forming a positive electrode coating film was changed.
Part by weight was changed to 40 parts by weight, and 8 parts by weight of polyvinylidene fluoride in the composition of the coating for forming a negative electrode coating was changed to 9.8 parts by weight, and hydroxypropyl cellulose in the composition of the coating for forming a negative electrode coating was changed. Example 1 was changed except that 2 parts by weight was changed to 0.2 parts by weight, and 80 parts by weight of N-methylpyrrolidone in the composition of the paint for forming a negative electrode coating film was changed to 74 parts by weight.
In the same manner as in the above, an R5 type lithium secondary battery was produced.
【００４７】実施例４ 実施例１の正極塗膜形成用塗料の組成中のポリビニリデ
ンフルオライド３．２重量部を０．８重量部に変更し、
正極塗膜形成用塗料の組成中のヒドロキシプロピルセル
ロース０．８重量部を３．２重量部に変更し、正極塗膜
形成用塗料の組成中のＮ−メチルピロリドン４５重量部
を５２重量部に変更し、負極塗膜形成用塗料の組成中の
ポリビニリデンフルオライド８重量部を２重量部に変更
し、負極塗膜形成用塗料の組成中のヒドロキシプロピル
セルロース２重量部を８重量部に変更し、負極塗膜形成
用塗料の組成中のＮ−メチルピロリドン８０重量部を４
８重量部に変更したほかは、実施例１と同様にＲ５形の
リチウム二次電池を作製した。Example 4 3.2 parts by weight of polyvinylidene fluoride in the composition of the coating material for forming a positive electrode coating film of Example 1 was changed to 0.8 parts by weight.
0.8 parts by weight of hydroxypropyl cellulose in the composition of the coating for forming a positive electrode coating was changed to 3.2 parts by weight, and 45 parts by weight of N-methylpyrrolidone in the composition of the coating for forming a positive electrode coating was changed to 52 parts by weight. 8 parts by weight of polyvinylidene fluoride in the composition of the coating for forming a negative electrode coating were changed to 2 parts by weight, and 2 parts by weight of hydroxypropyl cellulose in the composition of the coating for forming a negative electrode coating were changed to 8 parts by weight. Then, 80 parts by weight of N-methylpyrrolidone in the composition of the paint for forming a negative electrode coating film was added to 4 parts by weight.
An R5-type lithium secondary battery was fabricated in the same manner as in Example 1, except that the weight was changed to 8 parts by weight.
【００４８】実施例５ 実施例２の正極塗膜形成用塗料の組成中のヒドロキシプ
ロピルセルロースをメチルセルロースに変更し、負極塗
膜形成用塗料の組成中のヒドロキシプロピルセルロース
をメチルセルロースに変更したほかは、実施例２と同様
にＲ５形のリチウム二次電池を作製した。Example 5 The procedure of Example 2 was repeated, except that hydroxypropyl cellulose in the composition of the coating for forming a positive electrode coating was changed to methyl cellulose, and hydroxypropyl cellulose in the composition of a coating for forming a negative electrode coating was changed to methyl cellulose. An R5-type lithium secondary battery was manufactured in the same manner as in Example 2.
【００４９】比較例１ 実施例１の正極塗膜形成用塗料の組成中のポリビニリデ
ンフルオライド３．２重量部を４重量部に変更し、正極
塗膜形成用塗料の組成中のヒドロキシプロピルセルロー
ス０．８重量部を０重量部に変更し、正極塗膜形成用塗
料の組成中のＮ−メチルピロリドン４５重量部を４０重
量部に変更し、負極塗膜形成用塗料の組成中のポリビニ
リデンフルオライド８重量部を１０重量部に変更し、負
極塗膜形成用塗料の組成中のヒドロキシプロピルセルロ
ース２重量部を０重量部に変更し、負極塗膜形成用塗料
の組成中のＮ−メチルピロリドン８０重量部を７５重量
部に変更したほかは、実施例１と同様にＲ５形のリチウ
ム二次電池を作製した。Comparative Example 1 3.2 parts by weight of polyvinylidene fluoride in the composition of the coating for forming a positive electrode coating film of Example 1 was changed to 4 parts by weight, and hydroxypropyl cellulose in the composition of the coating for forming a positive electrode coating film was changed to 4 parts by weight. 0.8 parts by weight was changed to 0 parts by weight, 45 parts by weight of N-methylpyrrolidone in the composition of the coating for forming a positive electrode coating was changed to 40 parts by weight, and polyvinylidene in the composition of a coating for forming a negative electrode coating was changed. 8 parts by weight of fluoride was changed to 10 parts by weight, 2 parts by weight of hydroxypropyl cellulose in the composition of the coating for forming a negative electrode coating was changed to 0 parts by weight, and N-methyl in the composition of the coating for forming a negative electrode coating was changed to 0 part by weight. An R5-type lithium secondary battery was produced in the same manner as in Example 1 except that the amount of pyrrolidone was changed from 80 parts by weight to 75 parts by weight.
【００５０】この比較例１の電池を実施例１の電池と対
比して詳しく説明すると、この比較例１では、正極の塗
膜組成（正極塗膜形成用塗料の組成から溶剤のＮ−メチ
ルピロリドンを除いたもの）中のバインダーの含有量は
実施例１と同様に４重量部にしているが、セルロース系
ポリマーを使用せず、そのぶんポリビニリデンフルオラ
イド系ポリマーを増量し、負極の塗膜組成（負極塗膜形
成用塗料の組成から溶剤のＮ−メチルピロリドンを除い
たもの）中のバインダーの含有量は実施例１と同様に１
０重量部にしているが、セルロース系ポリマーを使用せ
ず、そのぶんポリビニリデンフルオライド系ポリマーを
増量し、それらに応じて、溶剤のＮ−メチルピロリドン
の使用量を少なく調節した。The battery of Comparative Example 1 will be described in detail in comparison with the battery of Example 1. In Comparative Example 1, the coating composition of the positive electrode (from the composition of the coating for forming a positive electrode coating, the solvent N-methylpyrrolidone was used) The content of the binder in Example 1 was 4 parts by weight in the same manner as in Example 1, but the amount of the polyvinylidene fluoride-based polymer was increased without using the cellulose-based polymer, and the coating film of the anode was removed. The content of the binder in the composition (the composition of the paint for forming a negative electrode coating film excluding N-methylpyrrolidone as a solvent) was 1 in the same manner as in Example 1.
Although the amount was 0 parts by weight, the amount of the polyvinylidene fluoride-based polymer was increased without using the cellulose-based polymer, and accordingly, the amount of N-methylpyrrolidone used as the solvent was adjusted to be small.
【００５１】上記のようにして作製した実施例１〜５お
よび比較例１の電池について充放電を繰り返した時の電
池容量の変化を測定した。その結果を表１に示す。な
お、電池容量の測定方法はつぎの通りである。With respect to the batteries of Examples 1 to 5 and Comparative Example 1 produced as described above, the change in the battery capacity when charging and discharging were repeated was measured. Table 1 shows the results. The method for measuring the battery capacity is as follows.
【００５２】電池容量の測定方法：充放電電流をＣで表
示した場合、Ｒ５形で５６０ｍＡを１Ｃとして充放電を
行った。充電は１Ｃの電流制限回路を設けて４．１Ｖの
定電圧で行い、放電は電池の電極間電圧が２．７５Ｖに
低下するまで行った。そして、各電池について、上記条
件下で充放電１回目、１００回目、２００回目、３００
回目、４００回目、５００回目の放電容量を測定し、実
施例１の電池の充放電１回目の放電容量を１００％と
し、それと他の電池の充放電１回目の電池容量との比な
らびに実施例１〜５および比較例１の電池の充放電１０
０回目、２００回目、３００回目、４００回目、５００
回目の放電容量の比を求めた。その結果を電池容量
（％）として表１に示す。Method for measuring battery capacity: When the charge / discharge current was indicated by C, charge / discharge was performed with R5 type at 560 mA as 1C. Charging was performed at a constant voltage of 4.1 V with a 1 C current limiting circuit, and discharging was performed until the voltage between the electrodes of the battery dropped to 2.75 V. Then, for each battery, the first charge, the 100th charge, the 200th charge,
The discharge capacity at the 400th, 400th, and 500th times was measured, and the discharge capacity at the first charge / discharge of the battery of Example 1 was set to 100%, and the ratio of the discharge capacity to the first charge / discharge battery capacity of the other batteries and Examples Charge and discharge 10 of batteries of Comparative Examples 1 to 5 and 1
0, 200, 300, 400, 500
The ratio of the discharge capacity at the second time was determined. Table 1 shows the results as battery capacity (%).
【００５３】[0053]
【表１】 [Table 1]
【００５４】表１に示す実施例１〜５の電池の電池容量
の減少と比較例１の電池の電池容量の減少との対比から
明らかなように、バインダーとしてポリビニリデンフル
オライド系ポリマーとセルロース系ポリマーとを用いた
実施例１〜５の電池は、充放電を繰り返した場合の電池
容量の減少が少なく、かつ充放電１回目の電池容量が大
きく、高容量であった。As is clear from the comparison between the decrease in the battery capacity of the batteries of Examples 1 to 5 and the decrease in the battery capacity of the battery of Comparative Example 1 shown in Table 1, the polyvinylidene fluoride-based polymer and the cellulose-based binder were used as binders. In the batteries of Examples 1 to 5 using the polymer, the decrease in the battery capacity when charge and discharge were repeated was small, and the battery capacity in the first charge and discharge was large and high.
【００５５】これに対して、バインダーとしてセルロー
ス系ポリマーを用いずビニリデンフルオライド系ポリマ
ーのみを用いた比較例１の電池は、充放電を繰り返した
場合の電池容量の減少が大きかった。On the other hand, in the battery of Comparative Example 1 using only the vinylidene fluoride-based polymer without using the cellulose-based polymer as the binder, the battery capacity was significantly reduced when charge and discharge were repeated.
【００５６】[0056]
【発明の効果】以上説明したように、本発明によれば、
充放電を繰り返した場合の電池容量の減少が少ない、高
容量のリチウム二次電池を提供することができた。As described above, according to the present invention,
A high-capacity lithium secondary battery with a small decrease in battery capacity when charging and discharging are repeated was provided.
【図１】本発明のリチウム二次電池の一例を模式的に示
す断面図である。FIG. 1 is a cross-sectional view schematically showing one example of a lithium secondary battery of the present invention.
１ 正極 ２ 負極 ３ セパレータ ４ 電解液 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 4 Electrolyte
Claims (1)
パレータを介して対向させるリチウム二次電池におい
て、上記シート状の正極およびシート状の負極のうち少
なくとも一方のシート状の電極が導電性基体の少なくと
も一方の面に少なくとも活物質とバインダーを含有する
塗膜を形成したものからなり、上記バインダーが、少な
くとも、主成分モノマーとしてビニリデンフルオライド
を含むポリビニリデンフルオライド系ポリマーと、セル
ロース系ポリマーとを含むことを特徴とするリチウム二
次電池。In a lithium secondary battery in which a sheet-shaped positive electrode and a sheet-shaped negative electrode are opposed to each other with a separator interposed therebetween, at least one of the sheet-shaped positive electrode and the sheet-shaped negative electrode is electrically conductive. A coating film containing at least an active material and a binder formed on at least one surface of a substrate, wherein the binder is at least a polyvinylidene fluoride-based polymer containing vinylidene fluoride as a main component monomer, and a cellulose-based polymer. And a lithium secondary battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10134019A JPH11329443A (en) | 1998-05-15 | 1998-05-15 | Lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10134019A JPH11329443A (en) | 1998-05-15 | 1998-05-15 | Lithium secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11329443A true JPH11329443A (en) | 1999-11-30 |
Family
ID=15118486
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10134019A Withdrawn JPH11329443A (en) | 1998-05-15 | 1998-05-15 | Lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11329443A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2357896A (en) * | 1999-12-14 | 2001-07-04 | Sanyo Electric Co | Lithium secondary battery and battery device comprising same |
| JP2002042784A (en) * | 2000-07-25 | 2002-02-08 | Hitachi Maxell Ltd | Nonaqueous secondary battery |
| WO2004049475A1 (en) * | 2002-11-22 | 2004-06-10 | Kureha Chemical Industry Company, Limited | Binder composition for electrode of nonaqueous electrolyte battery, and electrode mixture, electrode and battery using same |
| JP2006236859A (en) * | 2005-02-25 | 2006-09-07 | Toyota Motor Corp | Treating method of lithium battery |
-
1998
- 1998-05-15 JP JP10134019A patent/JPH11329443A/en not_active Withdrawn
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2357896A (en) * | 1999-12-14 | 2001-07-04 | Sanyo Electric Co | Lithium secondary battery and battery device comprising same |
| US6660433B2 (en) | 1999-12-14 | 2003-12-09 | Sanyo Electric Co., Ltd. | Lithium secondary battery and battery device comprising same |
| GB2357896B (en) * | 1999-12-14 | 2004-03-17 | Sanyo Electric Co | Lithium secondary battery and battery device comprising same |
| JP2002042784A (en) * | 2000-07-25 | 2002-02-08 | Hitachi Maxell Ltd | Nonaqueous secondary battery |
| WO2004049475A1 (en) * | 2002-11-22 | 2004-06-10 | Kureha Chemical Industry Company, Limited | Binder composition for electrode of nonaqueous electrolyte battery, and electrode mixture, electrode and battery using same |
| JPWO2004049475A1 (en) * | 2002-11-22 | 2006-03-30 | 株式会社クレハ | Non-aqueous electrolyte battery electrode binder composition and use thereof |
| JP4851092B2 (en) * | 2002-11-22 | 2012-01-11 | 株式会社クレハ | Non-aqueous electrolyte battery electrode binder composition and use thereof |
| JP2006236859A (en) * | 2005-02-25 | 2006-09-07 | Toyota Motor Corp | Treating method of lithium battery |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3539518B2 (en) | Lithium secondary battery | |
| JP4502311B2 (en) | Method for manufacturing lithium secondary battery | |
| JP2002237293A (en) | Nonaqueous electrolyte secondary battery and its manufacturing method | |
| JP4502332B2 (en) | Manufacturing method of sheet-like positive electrode | |
| JPH1145720A (en) | Lithium secondary battery | |
| JPH113710A (en) | Lithium secondary battery | |
| JPH113709A (en) | Manufacture of lithium secondary battery | |
| JP2003272704A (en) | Nonaqueous secondary battery | |
| JPH10106540A (en) | Lithium secondary battery | |
| JP2000357505A (en) | Nonaqueous electrolyte secondary battery | |
| JPH11354125A (en) | Lithium secondary battery | |
| JP5126851B2 (en) | Lithium-containing transition metal chalcogenide, method for producing the same, and method for producing a non-aqueous secondary battery | |
| JP4069988B2 (en) | Lithium ion secondary battery | |
| JP2004296420A (en) | Organic electrolyte battery | |
| JP4636650B2 (en) | Non-aqueous secondary battery | |
| JPH11329443A (en) | Lithium secondary battery | |
| JP3449679B2 (en) | Lithium secondary battery | |
| JP4878690B2 (en) | Lithium secondary battery | |
| JP2003151559A (en) | Organic electrolyte battery | |
| JPH11354127A (en) | Lithium secondary battery | |
| JPH10255760A (en) | Lithium secondary battery | |
| JP2004247187A (en) | Organic electrolytic battery | |
| JP2004158362A (en) | Organic electrolyte liquid battery | |
| JPH10233216A (en) | Lithium secondary battery | |
| JP4863238B2 (en) | Non-aqueous secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20050802 |