JP2002033106A - Slurry for lithium ion secondary battery electrode and its utilization - Google Patents
Slurry for lithium ion secondary battery electrode and its utilizationInfo
- Publication number
- JP2002033106A JP2002033106A JP2000216825A JP2000216825A JP2002033106A JP 2002033106 A JP2002033106 A JP 2002033106A JP 2000216825 A JP2000216825 A JP 2000216825A JP 2000216825 A JP2000216825 A JP 2000216825A JP 2002033106 A JP2002033106 A JP 2002033106A
- Authority
- JP
- Japan
- Prior art keywords
- slurry
- secondary battery
- ion secondary
- lithium ion
- active material
- 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
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、リチウムイオン
二次電池電極用スラリーおよびその利用に関する。さら
に詳しくは、セルロースエーテル化合物とゴム粒子と水
と活物質を含むリチウムイオン二次電池電極用スラリ
ー、およびその利用に関する。The present invention relates to a slurry for an electrode of a lithium ion secondary battery and its use. More specifically, the present invention relates to a slurry for a lithium ion secondary battery electrode containing a cellulose ether compound, rubber particles, water and an active material, and its use.
【０００２】[0002]
【従来の技術】近年、ノート型パソコン、携帯電話、Ｐ
ＤＡなどの携帯端末の普及が著しい。これら携帯端末の
電源に用いられている二次電池には、リチウムイオン二
次電池（以下、単に「電池」ということがある）が多用
されている。携帯端末は、より快適な携帯性を求め、小
型化、薄型化、軽量化、高性能化が急速に進んだ。その
結果、携帯端末は様々な場で利用されるようになってい
る。利用範囲の増大に伴って電池に対しても、携帯端末
に対するのと同様に小型化、薄型化、軽量化、高性能化
が要求されてきた。2. Description of the Related Art In recent years, notebook personal computers, mobile phones, P
The spread of mobile terminals such as DA is remarkable. As a secondary battery used as a power source of these portable terminals, a lithium ion secondary battery (hereinafter, sometimes simply referred to as “battery”) is frequently used. As for mobile terminals, smaller, thinner, lighter, and higher-performance mobile phones have been demanded for more comfortable portability. As a result, mobile terminals have been used in various places. As the range of use has increased, batteries have also been required to be smaller, thinner, lighter, and have higher performance, as in portable terminals.
【０００３】こうした電池の性能向上のために、電極、
電解液、その他の電池部材の改良が検討されている。電
極については、活物質や集電体そのものの検討の他、活
物質を集電体に保持するためのバインダーに関する検討
もなされている。通常、任意の重合体からなるバインダ
ーが活物質を集電体に保持して電極を形成している。こ
うした電極は、バインダーと液状媒体とを混合し、これ
に必要に応じて任意の添加剤を加えてバインダー組成物
を得、これに活物質を加えて電極用スラリーとなし、こ
れを集電体に塗布、乾燥して製造される。バインダーと
しては、従来よりポリビニリデンフルオライド（ＰＶＤ
Ｆ）などのフッ素系重合体や、ジエン系ゴムなどの非フ
ッ素系重合体の使用が提案されている。これらの重合体
は、有機溶剤に溶解または水に分散させたバインダー組
成物に活物質を添加したスラリーとして電極製造に供さ
れている。In order to improve the performance of such batteries, electrodes,
Improvements in electrolytes and other battery members are being studied. Regarding the electrode, in addition to the study of the active material and the current collector itself, studies have been made on a binder for holding the active material on the current collector. Usually, a binder made of an arbitrary polymer holds an active material on a current collector to form an electrode. Such an electrode is obtained by mixing a binder and a liquid medium, adding an optional additive to the mixture as necessary to obtain a binder composition, adding an active material to the slurry, and forming a slurry for an electrode. And dried. Conventionally, polyvinylidene fluoride (PVD) has been used as the binder.
Use of a fluorine-based polymer such as F) or a non-fluorine-based polymer such as a diene rubber has been proposed. These polymers are used for electrode production as a slurry obtained by adding an active material to a binder composition dissolved in an organic solvent or dispersed in water.
【０００４】特開平１１−６７２１３号には、高分子ラ
テックスからなるバインダー組成物に平均重合度３００
〜１,８００、エーテル化度０.５〜１のカルボキシメチ
ルセルロースを添加することが提案されている。このバ
インダー組成物は、放電特性、高容量化、充放電サイク
ル特性、安定性に優れた電極を与えると記載されている
ものの、その電池容量がどの位であるかは明らかにされ
ていない。最近では、携帯端末の使用時間の延長や充電
時間の短縮などが望まれ、電池の高容量化と充電速度の
短縮、すなわち、レート特性の向上が急務となってい
る。しかしながら、先に知られたバインダー組成物を用
いても、電池の高容量化とレート特性の向上とを両立さ
せることは困難であった。JP-A-11-67213 discloses that a binder composition comprising a polymer latex has an average degree of polymerization of 300.
It has been proposed to add carboxymethylcellulose having a degree of etherification of 0.5 to 1,800 and a degree of etherification of 0.5 to 1. Although it is described that this binder composition provides an electrode having excellent discharge characteristics, high capacity, charge-discharge cycle characteristics, and stability, it is not clear how much the battery capacity is. Recently, it has been desired to extend the use time of the portable terminal and the charging time, and it is urgently required to increase the capacity and the charging speed of the battery, that is, to improve the rate characteristics. However, even with the use of the previously known binder composition, it has been difficult to achieve both high battery capacity and improved rate characteristics.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、上記
のような技術の現況に鑑み、容量が高く、かつレート特
性に優れたリチウムイオン二次電池を与えることができ
る電極用スラリーを提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a slurry for an electrode capable of providing a lithium ion secondary battery having a high capacity and excellent rate characteristics in view of the above state of the art. Is to do.
【０００６】[0006]
【課題を解決するための手段】発明者らは、セルロース
エーテル化合物とゴム粒子と水と活物質を含むリチウム
イオン二次電池電極用スラリーにおいて、重合度の低い
セルロースエーテル化合物を用い、かつ、活物質として
黒鉛化度の高い炭素質材料を組み合わせ用いて負極を製
造すると、意外にも、リチウムイオン二次電池の高容量
化とレート特性の向上とを両立させることができること
を見出した。Means for Solving the Problems The inventors have used a cellulose ether compound having a low degree of polymerization in a slurry for a lithium ion secondary battery electrode containing a cellulose ether compound, rubber particles, water, and an active material. It has been surprisingly found that, when a negative electrode is manufactured using a combination of a carbonaceous material having a high degree of graphitization as a substance, both high capacity and improved rate characteristics of a lithium ion secondary battery can be achieved.
【０００７】かくして、本発明によれば、第一の発明と
して、セルロースエーテル化合物とゴム粒子と水と活物
質を含むリチウムイオン二次電池電極用スラリーであっ
て、当該セルロースエーテル化合物の平均重合度が１５
０以上３００未満であり、かつ活物質が黒鉛化度０．８
以上の炭素質材料であることを特徴とするリチウムイオ
ン二次電池電極用スラリーが提供される。Thus, according to the present invention, as a first invention, there is provided a slurry for a lithium ion secondary battery electrode comprising a cellulose ether compound, rubber particles, water and an active material, wherein the average degree of polymerization of the cellulose ether compound is Is 15
0 or more and less than 300, and the active material has a degree of graphitization of 0.8
A slurry for a lithium ion secondary battery electrode characterized by being the above carbonaceous material is provided.
【０００８】さらに、第二の発明として、第一の発明に
係るスラリーを用いて製造されたリチウムイオン二次電
池用負極が提供され、さらに第三の発明として、第二の
発明に係る負極を具えたリチウムイオン二次電池が提供
される。Further, as a second invention, there is provided a negative electrode for a lithium ion secondary battery manufactured by using the slurry according to the first invention, and as a third invention, a negative electrode according to the second invention is provided. Provided is a lithium ion secondary battery comprising the same.
【０００９】[0009]
【発明の実施の形態】１．リチウムイオン二次電池電極
用スラリー 本発明の電極用スラリーは、重合度が低いセルロースエ
ーテル化合物とゴム粒子と水と、活物質として黒鉛化度
の高い炭素質材料を含むスラリーである。スラリーに含
まれるセルロースエーテル化合物は、その平均重合度が
１５０以上３００未満であることで特徴づけられる。セ
ルロースエーテル化合物の平均重合度がこの範囲である
と、セルロースエーテル化合物の水への溶解性が確保で
き、表面が平滑な電極を得ることができ、さらに電池の
高容量化とレート特性の向上とを両立させることができ
る。平均重合度が小さすぎるとレート特性はよくなるが
電池容量が低くなり、逆に、重合度が上記範囲を超える
と高レート（充電時の電流量を多い状態）での高電池容
量の確保が困難となる。セルロースエーテル化合物のエ
ーテル化度については格別の限定はないが通常０．５〜
１．０のものが好ましく用いられる。BEST MODE FOR CARRYING OUT THE INVENTION The slurry for an electrode of a lithium ion secondary battery The slurry for an electrode of the present invention is a slurry containing a cellulose ether compound having a low degree of polymerization, rubber particles, water, and a carbonaceous material having a high degree of graphitization as an active material. The cellulose ether compound contained in the slurry is characterized by having an average degree of polymerization of 150 or more and less than 300. When the average degree of polymerization of the cellulose ether compound is within this range, the solubility of the cellulose ether compound in water can be ensured, and an electrode having a smooth surface can be obtained. Can be compatible. If the average degree of polymerization is too small, the rate characteristics will be good, but the battery capacity will be low. Conversely, if the degree of polymerization exceeds the above range, it will be difficult to secure a high battery capacity at a high rate (a large amount of current during charging). Becomes The degree of etherification of the cellulose ether compound is not particularly limited, but is usually 0.5 to
1.0 is preferably used.
【００１０】セルロースエーテル化合物の具体例として
は、カルボキシメチルセルロース、カルボキシエチルセ
ルロースおよびヒドロキシエチルセルロース、ならびに
これらのリチウム塩、ナトリウム塩、カリウム塩などの
アルカリ金属塩およびアンモニウム塩が挙げられる。こ
れらの中でも、カルボキシメチルセルロースのアルカリ
金属塩が好ましい。本発明のスラリー中のセルロースエ
ーテル化合物の含有量は、スラリー重量に基づき、通常
０．１〜１０重量％、好ましくは０．２〜５重量％であ
り、またゴムの含有量（固形分換算）は、通常０．１〜
６０重量％、好ましくは０．２〜４０重量％である。Specific examples of the cellulose ether compound include carboxymethylcellulose, carboxyethylcellulose and hydroxyethylcellulose, and alkali metal salts such as lithium salt, sodium salt and potassium salt, and ammonium salts thereof. Of these, alkali metal salts of carboxymethyl cellulose are preferred. The content of the cellulose ether compound in the slurry of the present invention is usually 0.1 to 10% by weight, preferably 0.2 to 5% by weight, based on the weight of the slurry, and the rubber content (in terms of solid content). Is usually 0.1 to
It is 60% by weight, preferably 0.2 to 40% by weight.
【００１１】スラリー中のゴム粒子と水は、通常ゴムの
水分散液の状態で調製すればよい。こうしたゴム粒子の
水分散体としては、例えば、スチレン・ブタジエン共重
合体ゴム（ＳＢＲ）などのスチレン・共役ジエン共重合
体（ＳＢ)ゴムラテックス、ニトリル・ブタジエン共重
合体ゴム（ＮＢＲ）などのニトリル・共役ジエン共重合
体ゴムラテックス、ポリオルガノシロキサンなどのシリ
コーンゴムラテックス、アクリル酸アルキルエステルの
重合、またはアクリル酸アルキルエステルとエチレン性
不飽和カルボン酸および／またはその他のエチレン性不
飽和単量体との共重合により得られるアクリルゴムラテ
ックス、ならびにビニリデンフルオライド共重合体ゴム
などのフッ素ゴムラテックスが挙げられる。The rubber particles and water in the slurry may be usually prepared in the form of an aqueous rubber dispersion. Examples of the aqueous dispersion of such rubber particles include, for example, styrene / conjugated diene copolymer (SB) rubber latex such as styrene / butadiene copolymer rubber (SBR), and nitrile such as nitrile / butadiene copolymer rubber (NBR).・ Conjugated diene copolymer rubber latex, silicone rubber latex such as polyorganosiloxane, polymerization of alkyl acrylate, or alkyl acrylate and ethylenically unsaturated carboxylic acid and / or other ethylenically unsaturated monomer And fluororubber latex such as vinylidene fluoride copolymer rubber.
【００１２】ゴムの水分散液の製造方法は特に制限され
ないが、通常、それぞれ所定の単量体を常法に従って乳
化重合または懸濁重合することによって製造することが
できる。例えば、「実験化学講座」第２８巻、（日本化
学会編、丸善（株）発行）に記載された方法、すなわ
ち、攪拌機および加熱装置付きの密閉容器に水、分散剤
や乳化剤、架橋剤などの添加剤、開始剤および単量体を
所定の組成になるように加え、攪拌して単量体などを水
に分散または乳化させ、攪拌しながら温度を上昇させる
などの方法で重合を開始させる方法などによって、ゴム
粒子が水に分散した分散液を得ることができる。The method for producing the rubber aqueous dispersion is not particularly limited, but it can be usually produced by subjecting each of the predetermined monomers to emulsion polymerization or suspension polymerization according to a conventional method. For example, the method described in “Experimental Chemistry Course” Vol. 28 (edited by The Chemical Society of Japan, published by Maruzen Co., Ltd.), ie, water, a dispersant, an emulsifier, a crosslinking agent, etc. The additives, initiators and monomers are added so as to have a predetermined composition, and the monomers are dispersed or emulsified in water by stirring, and the polymerization is started by a method such as raising the temperature while stirring. By a method or the like, a dispersion in which rubber particles are dispersed in water can be obtained.
【００１３】本発明のリチウムイオン二次電池電極用ス
ラリーでは活物質として黒鉛化度０．８以上の炭素質材
料が用いられる。黒鉛化度は０．８５以上であることが
好ましい。なお、黒鉛化度は、Ｘ線回折の００２面など
の回折図形から測定される。黒鉛化度が０．８未満であ
ると電池の充電所要時間が増大し、レート特性が低下す
る。黒鉛化度が０．８以上の炭素質材料の具体例として
は、２，０００℃以上で焼成された人工黒鉛、グラファ
イト、天然黒鉛、ＭＣＭＢ、ピッチ系炭素繊維などが挙
げられ、これらの中では天然黒鉛が好ましい。In the slurry for a lithium ion secondary battery electrode of the present invention, a carbonaceous material having a graphitization degree of 0.8 or more is used as an active material. The degree of graphitization is preferably 0.85 or more. The degree of graphitization is measured from a diffraction pattern such as a 002 plane of X-ray diffraction. If the degree of graphitization is less than 0.8, the time required for charging the battery increases, and the rate characteristics deteriorate. Specific examples of the carbonaceous material having a degree of graphitization of 0.8 or more include artificial graphite, graphite, natural graphite, MCMB, and pitch-based carbon fibers fired at 2,000 ° C. or more. Natural graphite is preferred.
【００１４】本発明の電池電極用スラリー中の活物質の
量は特に制限されないが、通常、ゴム粒子に対して重量
基準で１０〜１，０００倍、好ましくは３０〜５００倍
である。活物質量が少なすぎると、集電体に形成された
活物質層に不活性な部分が多くなり、電極としての機能
が不十分になり、電池のレート特性の向上が達成困難に
なり易い。また、活物質量が多すぎると活物質が集電体
に十分固定されず脱落しやすくなる。本発明のスラリー
中の水は、集電体に塗布しやすい濃度に調節するために
必要であり、その量はセルロースエーテル化合物とゴム
粒子と活物質の合計１００重量部に対して２０〜１，０
００重量部、好ましくは５０〜５００重量部である。The amount of the active material in the battery electrode slurry of the present invention is not particularly limited, but is usually 10 to 1,000 times, preferably 30 to 500 times, the weight of rubber particles. If the amount of the active material is too small, the active material layer formed on the current collector has many inactive portions, the function as an electrode becomes insufficient, and it becomes difficult to improve the rate characteristics of the battery. On the other hand, if the amount of the active material is too large, the active material is not sufficiently fixed to the current collector, and easily falls off. The water in the slurry of the present invention is necessary to adjust the concentration to be easily applied to the current collector, and the amount thereof is 20 to 1, based on 100 parts by weight of the total of the cellulose ether compound, the rubber particles, and the active material. 0
00 parts by weight, preferably 50 to 500 parts by weight.
【００１５】必要に応じて、本発明のスラリーには、そ
の塗料性を向上させる粘度調整剤や流動化剤などの添加
剤を併用することができる。その具体例としては、ポリ
アクリル酸ナトリウムなどのポリアクリル酸塩、ポリビ
ニルアルコール、ポリエチレンオキシド、ポリビニルピ
ロリドン、アクリル酸またはアクリル酸塩とビニルアル
コールの共重合体、無水マレイン酸またはマレイン酸も
しくはフマル酸と酢酸ビニルの共重合体の完全または部
分ケン化物、変性ポリビニルアルコール、変性ポリアク
リル酸、ポリエチレングリコール、ポリカルボン酸、エ
チレン−ビニルアルコール共重合体、酢酸ビニル重合体
などの水溶性ポリマーなどが挙げられる。これらの添加
剤の使用割合は、必要に応じて自由に選択することがで
きる。また、活性炭などのカーボンや金属粉のような導
電材などを、本発明の目的を阻害しない範囲で添加する
ことができる。If necessary, the slurry of the present invention may contain additives such as a viscosity modifier and a fluidizing agent for improving the paint properties. Specific examples thereof include polyacrylates such as sodium polyacrylate, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, copolymers of acrylic acid or acrylates and vinyl alcohol, maleic anhydride or maleic acid or fumaric acid. Water-soluble polymers such as fully or partially saponified copolymers of vinyl acetate, modified polyvinyl alcohol, modified polyacrylic acid, polyethylene glycol, polycarboxylic acid, ethylene-vinyl alcohol copolymer, and vinyl acetate polymer. . The usage ratio of these additives can be freely selected as needed. In addition, a conductive material such as carbon such as activated carbon or metal powder can be added as long as the object of the present invention is not hindered.
【００１６】２．リチウムイオン二次電池用負極 本発明のリチウムイオン二次電池用負極は、上記本発明
のスラリーを金属箔などの集電体に塗布し、乾燥して集
電体表面に活物質を固定することで製造される。集電体
は、導電性材料からなるものであれば特に制限されない
が、通常、鉄、銅、アルミニウム、ニッケル、ステンレ
スなどの金属製のものを用いる。形状も特に制限されな
いが、通常、厚さ０.００１〜０.５ｍｍ程度のシート状
のものを用いる。2. The negative electrode for a lithium ion secondary battery The negative electrode for a lithium ion secondary battery of the present invention is obtained by applying the slurry of the present invention to a current collector such as a metal foil, drying the slurry, and fixing the active material on the current collector surface. Manufactured in. The current collector is not particularly limited as long as the current collector is made of a conductive material. Usually, a metal collector such as iron, copper, aluminum, nickel, and stainless steel is used. Although the shape is not particularly limited, a sheet having a thickness of about 0.001 to 0.5 mm is usually used.
【００１７】スラリーの集電体への塗布方法も特に制限
されない。例えば、ドクターブレード法、ディップ法、
リバースロール法、ダイレクトロール法、グラビア法、
エクストルージョン法、浸漬、ハケ塗りなどによって塗
布される。塗布する量も特に制限されないが、スラリー
を乾燥した後に形成される活物質層の厚さが通常０.０
０５〜５ｍｍ、好ましくは０.０１〜２ｍｍになる程度
の量である。乾燥方法も特に制限されず、例えば温風、
熱風、低湿風による乾燥、真空乾燥、（遠）赤外線や電
子線などの照射による乾燥が挙げられる。乾燥条件は、
通常は応力集中が起こって活物質層に亀裂が入ったり、
活物質層が集電体から剥離しない程度の速度範囲の中
で、できるだけ早く乾燥できるように調整する。さら
に、乾燥後の集電体をプレスすることにより電極を安定
させてもよい。プレス方法としては、金型プレスやロー
ルプレスなどの方法が挙げられる。The method of applying the slurry to the current collector is not particularly limited. For example, doctor blade method, dip method,
Reverse roll method, direct roll method, gravure method,
It is applied by an extrusion method, immersion, brush painting, or the like. The amount to be applied is not particularly limited, but the thickness of the active material layer formed after drying the slurry is usually 0.0.
The amount is about 0.05 to 5 mm, preferably about 0.01 to 2 mm. The drying method is not particularly limited, for example, warm air,
Drying by hot air, low-humidity air, vacuum drying, drying by irradiation with (far) infrared rays, electron beams, or the like can be given. Drying conditions are
Usually, stress concentration occurs and cracks occur in the active material layer,
Adjustment is made so that the active material layer can be dried as quickly as possible within a speed range in which the active material layer does not peel off from the current collector. Further, the electrode may be stabilized by pressing the dried current collector. As a pressing method, a method such as a die press or a roll press is used.
【００１８】３．リチウムイオン二次電池 本発明のリチウムイオン二次電池は、電解液と上記のリ
チウムイオン二次電池用負極、さらに正極を含み、必要
に応じてセパレーターなどの部品を用いて、常法に従っ
て製造されるものである。リチウムイオン二次電池の製
造方法は常用される方法でよい。例えば、正極と負極と
をセパレータを介して重ね合わせ、電池形状に応じて巻
く、折るなどして、電池容器に入れ、電解液を注入して
封口することによって製造される。電池の形状は、コイ
ン型、ボタン型、シート型、円筒型、角形、扁平型など
の何れであってもよい。3. Lithium-ion secondary battery The lithium-ion secondary battery of the present invention includes an electrolytic solution and the above-described negative electrode for a lithium-ion secondary battery, and further includes a positive electrode, and is manufactured according to a conventional method using components such as a separator as necessary. Things. The method for producing the lithium ion secondary battery may be a commonly used method. For example, it is manufactured by stacking a positive electrode and a negative electrode with a separator interposed therebetween, winding or folding according to the shape of the battery, placing the battery in a battery container, injecting an electrolyte, and sealing the battery. The shape of the battery may be any of a coin type, a button type, a sheet type, a cylindrical type, a square type, a flat type and the like.
【００１９】正極は、活物質として、ＬｉＣｏＯ2，Ｌ
ｉＮｉＯ2，ＬｉＭｎＯ2，ＬｉＭｎ2Ｏ4などのリチウム
含有複合金属酸化物などを用いて製造される。電解液は
通常、リチウムイオン二次電池用に用いられるものであ
ればいずれでもよく、負極活物質、正極活物質の種類に
応じて電池としての機能を発揮するものを選択すればよ
い。電解質としては、例えば、従来より公知のリチウム
塩がいずれも使用でき、ＬｉＣｌＯ4、ＬｉＢＦ6、Ｌｉ
ＰＦ6などが挙げられる。The positive electrode is made of LiCoO 2 , L as an active material.
It is manufactured using a lithium-containing composite metal oxide such as iNiO 2 , LiMnO 2 , and LiMn 2 O 4 . The electrolytic solution may be any one as long as it is generally used for a lithium ion secondary battery, and an electrolyte that exhibits a function as a battery may be selected according to the types of the negative electrode active material and the positive electrode active material. As the electrolyte, for example, any of conventionally known lithium salts can be used, and LiClO 4 , LiBF 6 , Li
Such as PF 6, and the like.
【００２０】これらの電解質を溶解させる溶媒（電解液
溶媒）は通常用いられるものであれば特に限定されるも
のではないが、プロピレンカーボネート、エチレンカー
ボネート、ブチレンカーボネート、ジメチルカーボネー
ト、ジエチルカーボネートなどのカーボネート類；γ−
ブチルラクトンなどのラクトン類；トリメトキシメタ
ン、１,２−ジメトキシエタン、ジエチルエーテル、２
−エトキシエタン、テトラヒドロフラン、２−メチルテ
トラヒドロフランなどのエーテル類；ジメチルスルホキ
シドなどのスルホキシド類；１,３−ジオキソラン、４
―メチル−１,３―ジオキソランなどのオキソラン類；
アセトニトリルやニトロメタンなどの含窒素化合物類；
ギ酸メチル、酢酸メチル、酢酸エチル、酢酸ブチル、プ
ロピオン酸メチル、プロピオン酸エチルなどの有機酸エ
ステル類；ジグライム類；トリグライム類；スルホラン
類；３−メチル−２−オキサゾリジノンなどのオキサゾ
リジノン類；１,３−プロパンスルトン、１,４−ブタン
スルトン、ナフタスルトンなどのスルトン類；などの単
独もしくは二種以上の混合溶媒が使用できる。Solvents for dissolving these electrolytes (electrolyte solvents) are not particularly limited as long as they are commonly used, but carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate and the like. Γ-
Lactones such as butyl lactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether, 2
Ethers such as ethoxyethane, tetrahydrofuran and 2-methyltetrahydrofuran; sulfoxides such as dimethylsulfoxide; 1,3-dioxolane;
Oxolanes such as -methyl-1,3-dioxolane;
Nitrogen-containing compounds such as acetonitrile and nitromethane;
Organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate and ethyl propionate; diglymes; triglymes; sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; Sultones such as propane sultone, 1,4-butane sultone and naphtha sultone; or a mixture of two or more solvents.
【００２１】[0021]
【実施例】以下に、実施例を挙げて本発明を具体的に説
明するが、本発明はこれに限定されるものではない。な
お、実施例における部および％は、特に断りがない限り
重量基準である。実施例および比較例において、電池特
性は以下の方法で測定した。 放電容量：下記の方法で製造したコイン型電池を用いて
２５℃雰囲気下、０Ｖから１．２Ｖまで、それぞれ０．
０１Ｃの定電流法によって３０サイクル目の放電容量
（単位＝ｍＡｈ／ｇ（活物質当たり））を求めた。この
値が大きいほど容量減が少なく良い結果である。EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% are based on weight unless otherwise specified. In Examples and Comparative Examples, battery characteristics were measured by the following methods. Discharge capacity: 0 to 1.2 V in a 25 ° C. atmosphere using a coin-type battery manufactured by the following method.
The discharge capacity at the 30th cycle (unit: mAh / g (per active material)) was determined by a constant current method of 01C. The larger the value, the smaller the capacity reduction, which is a good result.
【００２２】充放電レート特性：測定条件を、試験温度
４０℃、定電流量を０．１Ｃ、０．５Ｃ、および１Ｃに
変更たこと以外は、上記の放電容量の測定と同様の方法
により、各定電流量における３０サイクル目の放電容量
（単位 ｍＡｈ／ｇ（活物質当り））をそれぞれ測定し
た。２５℃、０．０１Ｃの定電流法により測定された３
０サイクル目の放電容量に対する４０℃での各定電流法
により測定された３０サイクル目の放電容量（単位ｍＡ
ｈ／ｇ（活物質当り））の割合を百分率で算出した。こ
の値が大きいほど、高速充電が可能であることを示唆す
る。Charge / discharge rate characteristics: Except that the measurement conditions were changed to a test temperature of 40 ° C. and a constant current amount of 0.1 C, 0.5 C, and 1 C, a method similar to the above-described discharge capacity measurement was used. The discharge capacity at the 30th cycle (unit: mAh / g (per active material)) at each constant current amount was measured. 3 measured by a constant current method at 25 ° C. and 0.01 C.
The discharge capacity at the 30th cycle measured by each constant current method at 40 ° C. with respect to the discharge capacity at the 0th cycle (unit: mA)
h / g (per active material)) was calculated in percentage. The higher the value, the faster the charging is possible.
【００２３】コイン型電池の製造 実施例１、２及び比較例１、２で調製されたリチウムイ
オン二次電池負極用スラリーを銅箔（厚さ１８μｍ）
に、ドクターブレード法によって均一に塗布し、１２０
℃、１５分間乾燥機で乾燥した後、さらに真空乾燥機に
て５ｍｍＨｇ、１２０℃で２時間減圧乾燥した後、２軸
のロールプレスによって活物質密度が１．５ｇ／ｃｍ3
となるように圧縮し、負極を得た。こうして得られた電
極を直径１５ｍｍの円形に切り抜いた。正極として、直
径１５ｍｍの金属リチウムを使用した。Production of Coin-Type Battery The slurry for the negative electrode of the lithium ion secondary battery prepared in Examples 1 and 2 and Comparative Examples 1 and 2 was made of copper foil (18 μm thick)
Is uniformly applied by a doctor blade method.
After drying with a dryer at 15 ° C. for 15 minutes, further drying under reduced pressure at 5 mmHg and 120 ° C. for 2 hours with a vacuum dryer, the active material density was 1.5 g / cm 3 by a biaxial roll press.
To obtain a negative electrode. The electrode thus obtained was cut into a circle having a diameter of 15 mm. As the positive electrode, metallic lithium having a diameter of 15 mm was used.
【００２４】直径１８ｍｍ、厚さ２５μｍの円形ポリプ
ロピレン製多孔膜からなるセパレーターを介在させて、
活物質が対極のリチウム金属に対向するように重ね合わ
せ、外装容器底面に正極が接触するように配置し、さら
に負極の上にエキスパンドメタルを配置し、ポリプロピ
レン製パッキンを設置したステンレス鋼製のコイン型外
装容器（直径２０ｍｍ、高さ１．８ｍｍ、ステンレス鋼
厚さ０．２５ｍｍ）中に収納した。With a separator made of a circular polypropylene porous membrane having a diameter of 18 mm and a thickness of 25 μm interposed,
A stainless steel coin with the active material superimposed on the opposite lithium metal, placed so that the positive electrode contacts the bottom of the outer container, expanded metal placed on the negative electrode, and polypropylene packing installed It was housed in a mold outer container (diameter 20 mm, height 1.8 mm, stainless steel thickness 0.25 mm).
【００２５】容器中に空気が残らないように電解液を注
入し、ポリプロピレン製パッキンを介させて外装容器に
厚さ０．２ｍｍのステンレス鋼のキャップをかぶせて固
定し、電池缶を封止して、直径２０ｍｍ、厚さ約２ｍｍ
のコイン型電池を製造した。電解液はプロピレンカーボ
ネート／エチレンカーボネート／ジエチルカーボネート
／ジメチルカーボネート／メチルエチルカーボネート＝
２０／２０／２０／２０／２０（２０℃での体積比）に
ＬｉＰＦ6が１モル／リットルの濃度で溶解した溶液を
用いた。An electrolyte is injected so that no air remains in the container, and a 0.2 mm-thick stainless steel cap is fixed on the outer container via a polypropylene packing, and the battery can is sealed. And diameter 20mm, thickness about 2mm
Was manufactured. The electrolyte was propylene carbonate / ethylene carbonate / diethyl carbonate / dimethyl carbonate / methyl ethyl carbonate =
A solution in which LiPF 6 was dissolved at a concentration of 1 mol / liter in 20/20/20/20/20 (volume ratio at 20 ° C.) was used.
【００２６】実施例１、２、比較例１，２ 表１に示す重合度とエーテル化度を有するカルボキシメ
チルセルロースナトリウム３部と、スチレン・ブタジエ
ン共重合体ゴムラテックス（スチレン含量３５％、固形
分濃度４０％）の固形分量３部となる量とを混合し、バ
インダー組成物を得、これに天然黒鉛（黒鉛化度０．９
９）９４部を加え、さらに水１１０部を加えて十分に混
合し、電池電極用スラリーを得た。得られたスラリーを
用いて負極を製造し、さらに電池を製造し、放電容量と
充放電レート特性を評価した。結果を表１に示す。 Examples 1 and 2, Comparative Examples 1 and 2 3 parts of sodium carboxymethylcellulose having a polymerization degree and an etherification degree shown in Table 1 and a styrene / butadiene copolymer rubber latex (styrene content 35%, solid content concentration) 40%) to obtain a binder composition, which was mixed with natural graphite (graphitization degree 0.9).
9) 94 parts were added, and 110 parts of water were further added and mixed well to obtain a slurry for a battery electrode. A negative electrode was manufactured using the obtained slurry, and a battery was further manufactured. The discharge capacity and charge / discharge rate characteristics were evaluated. Table 1 shows the results.
【００２７】[0027]
【表１】 [Table 1]
【００２８】[0028]
【発明の効果】低い重合度を有するセルロースエーテル
化合物とゴム粒子と水と黒鉛化度の高い炭素質材料とを
含む本発明のスラリーから作成される負極を用いると、
容量が高く、かつ充電速度が向上したリチウムイオン二
次電池が得られる。According to the present invention, a negative electrode prepared from the slurry of the present invention containing a cellulose ether compound having a low degree of polymerization, rubber particles, water and a carbonaceous material having a high degree of graphitization is used.
A lithium ion secondary battery having a high capacity and an improved charging rate can be obtained.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 5H029 AJ02 AJ03 AK03 AL06 AM03 AM04 AM05 AM07 CJ08 DJ08 DJ16 EJ12 HJ01 HJ11 5H050 AA02 AA08 BA17 CA08 CB07 DA03 DA11 EA23 FA17 GA10 HA01 HA11 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H029 AJ02 AJ03 AK03 AL06 AM03 AM04 AM05 AM07 CJ08 DJ08 DJ16 EJ12 HJ01 HJ11 5H050 AA02 AA08 BA17 CA08 CB07 DA03 DA11 EA23 FA17 GA10 HA01 HA11
Claims (3)
水と活物質を含むリチウムイオン二次電池電極用スラリ
ーであって、当該セルロースエーテル化合物の平均重合
度が１５０以上３００未満であり、かつ活物質が黒鉛化
度０．８以上の炭素質材料であることを特徴とするリチ
ウムイオン二次電池電極用スラリー。1. A slurry for a lithium ion secondary battery electrode comprising a cellulose ether compound, rubber particles, water and an active material, wherein the cellulose ether compound has an average degree of polymerization of 150 to less than 300, and the active material is A slurry for a lithium ion secondary battery electrode, which is a carbonaceous material having a degree of graphitization of 0.8 or more.
れたリチウムイオン二次電池用負極。2. A negative electrode for a lithium ion secondary battery produced by using the slurry according to claim 1.
オン二次電池。3. A lithium ion secondary battery comprising the negative electrode according to claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000216825A JP2002033106A (en) | 2000-07-18 | 2000-07-18 | Slurry for lithium ion secondary battery electrode and its utilization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000216825A JP2002033106A (en) | 2000-07-18 | 2000-07-18 | Slurry for lithium ion secondary battery electrode and its utilization |
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| Publication Number | Publication Date |
|---|---|
| JP2002033106A true JP2002033106A (en) | 2002-01-31 |
Family
ID=18712021
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000216825A Pending JP2002033106A (en) | 2000-07-18 | 2000-07-18 | Slurry for lithium ion secondary battery electrode and its utilization |
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| Country | Link |
|---|---|
| JP (1) | JP2002033106A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004146253A (en) * | 2002-10-25 | 2004-05-20 | Sony Corp | Negative electrode and battery, and manufacturing method of these |
| JP2005011808A (en) * | 2003-06-20 | 2005-01-13 | Samsung Sdi Co Ltd | Negative electrode composite for lithium battery, and negative electrode and lithium battery using the composite |
| JP2007287570A (en) * | 2006-04-19 | 2007-11-01 | Iwate Univ | Lithium ion secondary battery |
| JP2010129332A (en) * | 2008-11-27 | 2010-06-10 | Toyota Motor Corp | Nonaqueous electrolyte secondary battery |
| WO2011121902A1 (en) * | 2010-03-31 | 2011-10-06 | パナソニック株式会社 | Negative electrode for a lithium-ion secondary battery, and lithium-ion secondary battery containing said negative electrode |
| WO2018168657A1 (en) * | 2017-03-13 | 2018-09-20 | 日本ゼオン株式会社 | Slurry composition for nonaqueous secondary battery functional layers, functional layer for nonaqueous secondary batteries, and nonaqueous secondary battery |
-
2000
- 2000-07-18 JP JP2000216825A patent/JP2002033106A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004146253A (en) * | 2002-10-25 | 2004-05-20 | Sony Corp | Negative electrode and battery, and manufacturing method of these |
| US7754381B2 (en) | 2002-10-25 | 2010-07-13 | Sony Corporation | Anode and battery, and manufacturing methods thereof |
| JP2005011808A (en) * | 2003-06-20 | 2005-01-13 | Samsung Sdi Co Ltd | Negative electrode composite for lithium battery, and negative electrode and lithium battery using the composite |
| JP2007287570A (en) * | 2006-04-19 | 2007-11-01 | Iwate Univ | Lithium ion secondary battery |
| JP2010129332A (en) * | 2008-11-27 | 2010-06-10 | Toyota Motor Corp | Nonaqueous electrolyte secondary battery |
| WO2011121902A1 (en) * | 2010-03-31 | 2011-10-06 | パナソニック株式会社 | Negative electrode for a lithium-ion secondary battery, and lithium-ion secondary battery containing said negative electrode |
| CN102428596A (en) * | 2010-03-31 | 2012-04-25 | 松下电器产业株式会社 | Negative Electrode For A Lithium-Ion Secondary Battery, And Lithium-Ion Secondary Battery Containing Said Negative Electrode |
| JPWO2011121902A1 (en) * | 2010-03-31 | 2013-07-04 | パナソニック株式会社 | Negative electrode for lithium ion secondary battery and lithium ion secondary battery including the same |
| US8728665B2 (en) | 2010-03-31 | 2014-05-20 | Panasonic Corporation | Negative electrode for lithium ion secondary battery and lithium ion secondary battery including the same |
| WO2018168657A1 (en) * | 2017-03-13 | 2018-09-20 | 日本ゼオン株式会社 | Slurry composition for nonaqueous secondary battery functional layers, functional layer for nonaqueous secondary batteries, and nonaqueous secondary battery |
| CN110326137A (en) * | 2017-03-13 | 2019-10-11 | 日本瑞翁株式会社 | Non-aqueous secondary battery functional layer paste compound, non-aqueous secondary battery functional layer and non-aqueous secondary battery |
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