JP3478077B2 - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JP3478077B2 JP3478077B2 JP22466997A JP22466997A JP3478077B2 JP 3478077 B2 JP3478077 B2 JP 3478077B2 JP 22466997 A JP22466997 A JP 22466997A JP 22466997 A JP22466997 A JP 22466997A JP 3478077 B2 JP3478077 B2 JP 3478077B2
- Authority
- JP
- Japan
- Prior art keywords
- easy
- secondary battery
- lithium secondary
- adhesion layer
- 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.)
- Expired - Lifetime
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Description
【０００１】[0001]
【産業上の利用分野】本発明はリチウム二次電池に存す
る。更に詳しくは、電解液に代えて（電解液を含有し
た）ポリマー電解質を用いたリチウム二次電池に存し、
高電位、高エネルギー密度でサイクル特性に優れたリチ
ウム二次電池に存する。FIELD OF THE INVENTION The present invention resides in a lithium secondary battery. More specifically, in a lithium secondary battery using a polymer electrolyte (containing an electrolyte solution) instead of the electrolyte solution,
It exists in a lithium secondary battery with high potential, high energy density, and excellent cycle characteristics.
【０００２】[0002]
【従来の技術】近年、カメラ一体型ＶＴＲ装置、オーデ
ィオ機器、携帯型コンピュータ、携帯電話等様々な機器
の小型化、軽量化が進んでおり、これら機器の電源とし
ての電池に対する高性能化要請が高まっている。中でも
電気自動車の動力源としての電池として高電圧、高エネ
ルギー密度で、且つ優れたサイクル特性の実現が可能な
リチウム二次電池の開発が盛んになっている。2. Description of the Related Art In recent years, various devices such as a VTR device with a built-in camera, an audio device, a portable computer, and a mobile phone have been reduced in size and weight, and there has been a demand for higher performance of a battery as a power source of these devices. It is rising. Above all, as a battery as a power source of an electric vehicle, a lithium secondary battery having a high voltage and a high energy density and capable of realizing excellent cycle characteristics has been actively developed.
【０００３】リチウム二次電池は、リチウムイオンを吸
蔵放出可能な正極と負極及び非水電解質液とからなり、
一般的に、リチウム二次電池における正極や負極は、ア
ルミニウム箔や銅箔の様な集電体上に正極（負極）活物
質、導電材料、及び結合剤（バインダー）、溶媒等を含
有する塗料を塗布、乾燥して製造する。しかし、金属か
ら成る集電体と結合剤から成る活物質層とのなじみが悪
く、巻き取り工程などの製造工程中で活物質層が剥離し
たり、電池容器中で電解液の浸透により活物質層中の結
合剤が膨潤して、活物質層が剥離するなどの問題が生じ
ていた。A lithium secondary battery comprises a positive electrode capable of inserting and extracting lithium ions, a negative electrode and a non-aqueous electrolyte solution.
Generally, a positive electrode or a negative electrode in a lithium secondary battery is a coating material containing a positive electrode (negative electrode) active material, a conductive material, a binder (binder), a solvent, etc. on a current collector such as an aluminum foil or a copper foil. Is applied and dried to manufacture. However, the compatibility between the current collector made of metal and the active material layer made of a binder is not good, and the active material layer peels off during the manufacturing process such as the winding process, or the active material is penetrated into the battery container due to the permeation of the electrolytic solution. There has been a problem that the binder in the layer swells and the active material layer peels off.
【０００４】この集電体と活物質層との接着性を改良す
るための手段の一般的な例として、集電体の表面を粗面
化する手法がある。表面の粗面化方法としては、機械的
研磨法、電解研磨法または化学研磨法が挙げられ、例え
ば機械的研磨法としては、研磨剤粒子を固着した研磨布
紙、砥石、エメリバフ、鋼線などを備えたワイヤ−ブラ
シなどで集電体表面を研磨する方法が知られている。As a general example of means for improving the adhesion between the current collector and the active material layer, there is a method of roughening the surface of the current collector. Examples of the surface roughening method include a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method.For example, the mechanical polishing method includes an abrasive cloth paper to which abrasive particles are fixed, a grindstone, an emery buff, a steel wire, etc. There is known a method of polishing the surface of the current collector with a wire brush or the like equipped with.
【０００５】しかし、上記の方法では電池容器中での長
時間にわたる電解液と活物質層との接触により、活物質
層の結合剤が膨潤するため、集電体と活物質層との間の
接着性を十分に保つには至っていない。さらに、粗面化
された集電体と活物質層との間の電気的接触性が不十分
かつ不均一であるので、電極内部で部分的に電気抵抗が
変化し、電池性能を十分に引き出すことができない。However, in the above method, the binder in the active material layer swells due to the contact between the electrolytic solution and the active material layer in the battery container for a long period of time, so that the binder between the current collector and the active material layer is swelled. It has not been able to maintain sufficient adhesiveness. Furthermore, since the electrical contact between the roughened current collector and the active material layer is insufficient and non-uniform, the electric resistance is partially changed inside the electrode, and the battery performance is sufficiently drawn out. I can't.
【０００６】また、集電体と活物質層との接着性を改良
する別の手段として、ＵＳ５５８０６８６等には、グラ
ファイトと結合剤を主成分とする易接着層を集電体と活
物質層の間に設ける方法が記載されている。グラファイ
ト粒子が集電体表面を粗面化するとともに、導電性をも
つグラファイト粒子の介在により集電体と活物質層の電
気的接触性を改善する効果があるものの、一般に、グラ
ファイトは結合剤に対するなじみが悪く、グラファイト
を結合剤中に分散する工程は長時間を要する。また、グ
ラファイトを含有する塗料は粘性が高いため、集電体上
に薄く塗布することが困難であり、電池の体積エネルギ
ー密度の面では不利である。さらに、グラファイトは、
ＤＢＰ吸油量が大きいので、分散に要する結合剤量を多
く必要とし、導電性粒子としてのグラファイトの特徴を
十分に発揮するに至っていない。このように、結合剤に
対する分散性が悪いグラファイトを使用して形成された
易接着層は、表面性が悪く、かつ塗膜が脆いという問題
点を有していた。[0006] As another means for improving the adhesiveness between the current collector and the active material layer, US Pat. No. 5,580,686 and the like include an easy-adhesion layer containing graphite and a binder as the main components of the current collector and the active material layer. The method of providing between is described. While graphite particles roughen the surface of the current collector and have the effect of improving the electrical contact between the current collector and the active material layer by interposing graphite particles having conductivity, graphite generally binds to the binder. It is not very familiar and the process of dispersing graphite in the binder takes a long time. Further, since the paint containing graphite has high viscosity, it is difficult to apply it thinly on the current collector, which is disadvantageous in terms of the volumetric energy density of the battery. In addition, graphite is
Since the DBP oil absorption is large, a large amount of binder is required for dispersion, and the characteristics of graphite as conductive particles have not been sufficiently exhibited. As described above, the easy-adhesion layer formed by using graphite having poor dispersibility in the binder has problems that the surface property is poor and the coating film is brittle.
【０００７】ところで、従来のリチウム二次電池では、
高電圧系電池の電解液として非水系の電解液が用いられ
ていた。ところが、非水系電解液を用いた電池は濾液や
発火の危険を有していることから，近年では、安全性を
向上させるために非水電解液を、例えばゲル状ポリマ−
に電解液を含有させた電解質の開発が行われている。特
にリチウム二次電池においては液体電解質を用いた際に
生ずるリチウムのデンドライト析出による内部短絡から
くる発熱、発火が問題となっており、ポリマー電解質の
適応が望まれていた。By the way, in the conventional lithium secondary battery,
A non-aqueous electrolytic solution has been used as an electrolytic solution for a high-voltage battery. However, since batteries using non-aqueous electrolytes have a risk of filtrate and ignition, in recent years, non-aqueous electrolytes have been used to improve safety, for example, gel polymer.
An electrolyte containing an electrolytic solution has been developed. Particularly, in a lithium secondary battery, heat generation and ignition due to an internal short circuit due to dendrite deposition of lithium, which occurs when a liquid electrolyte is used, poses a problem, and application of a polymer electrolyte has been desired.
【０００８】さらに上記のような、ゲル状ポリマー中に
電解液を含有した電解質等を含めたポリマ−電解質は、
従来のリチウム二次電池と異なりセパレータを用いずと
も、この二次電池系で使用されるセパレ−タ−の代用を
勤めることが可能となるので、ポリマー電解質を挟んで
正極と負極と接合させて用いることが出来る。この様な
ポリマーは液系に比して軽量で形状柔軟性を有するの
で、例えばシ−ト状が如き薄膜化が可能であり、軽量、
省スペースな電池が作成可能となる有利な点がある。Further, a polymer electrolyte including an electrolyte containing an electrolytic solution in a gel polymer as described above,
Unlike a conventional lithium secondary battery, it is possible to serve as a substitute for the separator used in this secondary battery system without using a separator.Therefore, a polymer electrolyte is sandwiched between the positive electrode and the negative electrode. Can be used. Since such a polymer is lighter in weight and has shape flexibility as compared with a liquid system, it is possible to form a thin film such as a sheet-like polymer, which is lightweight,
There is an advantage that a space-saving battery can be created.
【０００９】このようなポリマー電解質を用いたリチウ
ム二次電池においても、正極または負極活物質層は金属
からなる集電体上に形成されるので、正極または負極活
物質層と集電体との接着性を高め、良好な電気的接触を
得ることは必要である。しかしながら、集電体の粗面化
またはグラファイトを成分とする易接着層を設けるとい
った上記の従来の製造方法を用いても、十分な効果が得
られていない。Also in the lithium secondary battery using such a polymer electrolyte, since the positive electrode or negative electrode active material layer is formed on the current collector made of metal, the positive electrode or negative electrode active material layer and the current collector are separated from each other. It is necessary to increase adhesion and obtain good electrical contact. However, even if the above-mentioned conventional manufacturing method such as roughening the surface of the current collector or providing an easy-adhesion layer containing graphite as a component is not used, sufficient effects cannot be obtained.
【００１０】[0010]
【発明が解決しようとする課題】上記の様に、活物質層
の集電体への接着性は、主に集電体の粗面化によって行
われており、粗面化された集電体と活物質層との間の電
気的接触性が不十分であるため、電池性能を十分に引き
出すことができず、また、電池容器中での長時間にわた
る電解液と活物質層との接触により、活物質層中の結合
剤が膨潤し、活物質層が集電体から剥離するという問題
点を有していた。一方、グラファイトを成分とする易接
着層を設ける手法では、グラファイトの分散に多量の結
合剤を必要とするため、導電剤としてのグラファイトの
特性を十分に活かせず、また、粘性が極めて高いため、
薄膜化が困難であり、塗膜の表面性も悪く脆いといった
欠点を有していた。As described above, the adhesion of the active material layer to the current collector is mainly performed by roughening the current collector, and the roughened current collector is used. Since the electrical contact between the active material layer and the active material layer is insufficient, the battery performance cannot be fully brought out, and the long time contact between the electrolytic solution and the active material layer in the battery container However, there is a problem that the binder in the active material layer swells and the active material layer peels off from the current collector. On the other hand, in the method of providing the easy-adhesion layer containing graphite as a component, a large amount of a binder is required to disperse the graphite, and therefore the characteristics of graphite as a conductive agent cannot be fully utilized, and since the viscosity is extremely high,
It was difficult to form a thin film and the coating film had poor surface properties and was brittle.
【００１１】[0011]
【課題を解決するための手段】本発明は上記実状に鑑み
て為されたものであり、高電位、高エネルギー密度でサ
イクル特性に優れたリチウム二次電池を得るために鋭意
検討した結果、箔状の集電体と活物質層との間に、導電
性フィラー及び界面活性剤を使用した易接着層を設ける
ことにより、集電体と活物質層との接着性および電気的
接触性の向上を計り且つ、サイクル特性に優れ、さらに
電池間のサイクル特性と放電容量のばらつきが少ないリ
チウム二次電池を得られることを見いだし、完成したも
のである。Means for Solving the Problems The present invention has been made in view of the above circumstances, and as a result of earnest studies to obtain a lithium secondary battery having a high potential, a high energy density and excellent cycle characteristics, a foil was obtained. between Jo of the current collector and the active material layer, by providing an easy-adhesion layer using a conductive filler and a surfactant to improve the adhesion and electrical contact between the current collector and the active material layer In addition, it was found that a lithium secondary battery having excellent cycle characteristics and less variation in cycle characteristics and discharge capacity among the batteries can be obtained, and the lithium secondary battery has been completed.
【００１２】更に詳しくは、本発明に於けるリチウム二
次電池の易接着層の導電性フィラーの平均粒子径とＤＢ
Ｐ吸油量が、本発明の目的とする特性の改良に重要な指
標になることを見出し、この目的を達成するためには、
導電性フィラーの平均粒子径を０．５μｍ以下、ＤＢＰ
吸油量を５０ｍｌ／１００ｇ以下、さらには、易接着層
の乾燥膜厚を０．０１〜５ｕｍにすることが必用である
ことを突き止めた。このように導電性フィラーの平均粒
子径を０．５μｍ以下、ＤＢＰ吸油量を５０ｍｌ／１０
０ｇ以下、さらには、易接着層の乾燥膜厚を０．０１〜
５μｍとすることで高電位、高エネルギー密度でサイク
ル特性を向上することができるのである。More specifically, the average particle diameter and DB of the conductive filler in the easily adhesive layer of the lithium secondary battery according to the present invention are
It was found that the P oil absorption amount is an important index for the improvement of the properties of the present invention, and in order to achieve this object,
The average particle diameter of the conductive filler is 0.5 μm or less, DBP
It was found that it is necessary to set the oil absorption amount to 50 ml / 100 g or less, and further to set the dry film thickness of the easy-adhesion layer to 0.01 to 5 μm. Thus, the conductive filler has an average particle diameter of 0.5 μm or less and a DBP oil absorption of 50 ml / 10.
0 g or less, and further, the dry film thickness of the easy-adhesion layer is 0.01 to
By setting the thickness to 5 μm, the cycle characteristics can be improved with high potential and high energy density.
【００１３】 更に好ましくは、本発明は正極、負極及
びポリマー電解質を備えたリチウム二次電池であって、
正極が、箔状の正極集電体上に導電性フィラーを含有す
る易接着層、リチウムイオンを吸蔵放出可能な化合物を
含む正極活物質層を順次設けたものであり、該易接着層
の導電性フィラーの平均粒子径が０．５μｍ以下、ＤＢ
Ｐ吸油量が５０ｍｌ／１００ｇ以下であり、かつ、易接
着層の乾燥膜厚が０．０１〜５μｍであることを特徴と
するリチウム二次電池に存する。More preferably, the present invention is a lithium secondary battery comprising a positive electrode, a negative electrode and a polymer electrolyte,
The positive electrode is one in which an easy-adhesion layer containing a conductive filler and a positive-electrode active material layer containing a compound capable of occluding and releasing lithium ions are sequentially provided on a foil-shaped positive electrode current collector, and the easy-adhesion layer has a conductive property. Average particle size of the hydrophilic filler is 0.5 μm or less, DB
The lithium secondary battery is characterized in that the P oil absorption is 50 ml / 100 g or less and the dry film thickness of the easy-adhesion layer is 0.01 to 5 μm.
【００１４】[0014]
【発明の実施の形態】本発明のリチウム二次電池は集電
体と電池活物質層との間に易接着層を設けた電極を有
し、特にはポリマー電解質を主たる構成要件とするもの
である。まず本発明のリチウム二次電池における電極に
ついて説明する。一般的に、リチウム二次電池における
正極や負極は、アルミニウム箔や銅箔の様な集電体上
に、正極（負極）活物質、導電材料、結合剤（バインダ
ー）、溶媒等を含有する塗料を塗布、乾燥して電池活物
質層を形成させて製造する。BEST MODE FOR CARRYING OUT THE INVENTION The lithium secondary battery of the present invention has an electrode in which an easy-adhesion layer is provided between a current collector and a battery active material layer, and particularly has a polymer electrolyte as a main constituent element. is there. First, the electrodes in the lithium secondary battery of the present invention will be described. Generally, a positive electrode or a negative electrode in a lithium secondary battery is a coating material containing a positive electrode (negative electrode) active material, a conductive material, a binder (binder), a solvent, etc. on a current collector such as an aluminum foil or a copper foil. Is applied and dried to form a battery active material layer, which is manufactured.
【００１５】本発明における正極に用いる活物質は、リ
チウムイオンを吸蔵放出可能な化合物が用いられ、例え
ば無機化合物としてはＦｅ、Ｃｏ、Ｎｉ、Ｍｎ、等の遷
移金属の遷移金属酸化物、リチウムと遷移金属との複合
酸化物、遷移金属硫化物等が挙げられる。具体的には、
ＭｎＯ、Ｖ2 Ｏ5 、Ｖ6 Ｏ13、ＴｉＯ2 等の遷移金属
酸化物粉末、ニッケル酸リチウム、コバルト酸リチウム
などのリチウムと遷移金属との複合酸化物粉末、ＴｉＳ
2 、ＦｅＳなどの遷移金属硫化物粉末が挙げられる。有
機化合物としては、例えばポリアニリン等の導電性ポリ
マー等が挙げられる。これらの無機化合物、有機化合物
は混合して用いても良い。As the active material used for the positive electrode in the present invention, a compound capable of inserting and extracting lithium ions is used. Examples of inorganic compounds include transition metal oxides of transition metals such as Fe, Co, Ni and Mn, and lithium. Examples thereof include complex oxides with transition metals, transition metal sulfides, and the like. In particular,
Transition metal oxide powder such as MnO, V 2 O 5 , V 6 O 13 and TiO 2 , composite oxide powder of lithium and transition metal such as lithium nickel oxide and lithium cobalt oxide, TiS
2 , transition metal sulfide powders such as FeS. Examples of the organic compound include conductive polymers such as polyaniline. These inorganic compounds and organic compounds may be used as a mixture.
【００１６】負極に用いられる活物質としては、リチウ
ムイオンを吸蔵放出可能な化合物が用いられ、例えばグ
ラファイトやコ−クス等が挙げられるが、特に安全性の
面からコ−クスが好ましい。これら正極、負極の活物質
の粒径は電池のその他の構成要件とのかねあいで適宜選
択すればよいが、通常１〜３０μｍ、特に１〜１０μ
ｍ、中でも３〜８μｍとすることで、活物質層中の空隙
率を容易に制御することが可能であるという効果がある
ので好ましい。As the active material used for the negative electrode, a compound capable of inserting and extracting lithium ions is used, and examples thereof include graphite and coke, and from the viewpoint of safety, coke is particularly preferable. The particle size of the active material of the positive electrode and the negative electrode may be appropriately selected in consideration of other constituent requirements of the battery, but is usually 1 to 30 μm, and particularly 1 to 10 μm.
It is preferable to set m, especially 3 to 8 μm, because it has an effect that the porosity in the active material layer can be easily controlled.
【００１７】結合剤としては、電解液等に対して安定で
ある必要があり耐候性、耐薬品性、耐熱性、難燃性等が
望まれる。さらにイオン伝導性に優れた材料が望ましく
例えば架橋性のポリエチレンオキシド樹脂等が挙げられ
る。さらに好ましくは、ポリエチレンオキシド樹脂末端
にアクリル基、メタアクリル基等を導入し、熱や紫外線
等により架橋させることが望ましい。The binder is required to be stable with respect to the electrolytic solution and is desired to have weather resistance, chemical resistance, heat resistance, flame retardancy and the like. Further, a material having excellent ionic conductivity is desirable, and examples thereof include a crosslinkable polyethylene oxide resin. More preferably, it is desirable to introduce an acrylic group, a methacrylic group, or the like at the end of the polyethylene oxide resin and crosslink with heat, ultraviolet rays, or the like.
【００１８】導電性物質としては、リチウムを吸蔵放出
可能な化合物粉末に適量混合して導電性を付与できる物
であれば特に制限は無いが、アセチレンブラック、カ−
ボンブラック、黒鉛などの炭素粉末や、使用する電極電
位で安定な金属粉末などが挙げられる。これら導電性物
質のＤＢＰ吸油量は１２０ｍｌ／１００ｇ以上が好まし
く、特に１５０ｍｌ／１００ｇ以上が電解液を保持する
という理由から好ましい。活物質との重量比は、９８／
２〜９０／１０の範囲が好ましい。活物質との重量比が
９８／２より大きいと，導電性物質の導電性が発揮され
ず、電極塗膜の抵抗が増加する。また、活物質との重量
比が９０／１０より小さいと，導電性物質の分散が困難
になることに加えて，活物質の重量の減少により、充放
電容量も減少する。The conductive substance is not particularly limited as long as it is a substance capable of imparting conductivity by mixing an appropriate amount with a compound powder capable of occluding and releasing lithium, but there is no particular limitation.
Examples thereof include carbon powders such as bonblack and graphite, and metal powders that are stable at the electrode potential used. The DBP oil absorption of these conductive substances is preferably 120 ml / 100 g or more, and particularly preferably 150 ml / 100 g or more because the electrolytic solution is retained. The weight ratio with the active material is 98 /
The range of 2 to 90/10 is preferable. When the weight ratio with the active material is larger than 98/2, the conductivity of the conductive material is not exhibited and the resistance of the electrode coating film increases. If the weight ratio of the active material is less than 90/10, it becomes difficult to disperse the conductive material, and the charge / discharge capacity is also reduced due to the weight reduction of the active material.
【００１９】溶媒としては、前記結合剤を溶解可能でか
つ容易に乾燥するものが好ましく、例えばアクリロニト
リル、ジメチルカ−ボネ−ト等が挙げられる。集電体と
しては、一般的に正極にアルミ箔を用い、負極に銅箔を
用いる。尚、負極材料として、負極集電体と負極活物質
層からなる負極を使用する代わりに、Ｌｉ金属箔を使用
することもできる。As the solvent, those capable of dissolving the binder and easily dried are preferable, and examples thereof include acrylonitrile and dimethyl carbonate. As the current collector, an aluminum foil is generally used for the positive electrode and a copper foil is used for the negative electrode. As the negative electrode material, a Li metal foil can be used instead of using the negative electrode composed of the negative electrode current collector and the negative electrode active material layer.
【００２０】本発明においては、集電体と活物質層との
間に、導電性フィラーを含有する易接着層を設ける。本
発明においては、易接着層における導電性フィラーの平
均粒子径は０．５μｍ以下である。この様な値に特定す
ることで、良好な接着性を保てるため、サイクル特性が
向上するという顕著な効果が得られる。これは、平均粒
子径０．５μｍ以下の導電性フィラーは、易接着層表面
に適度な表面粗さを与える効果によるものである。導電
性フィラーの平均粒子径が０．５ｕｍを越えると、易接
着層の表面が粗れすぎて、易接着層と活物質層との間の
電気的接触性が不十分かつ不均一であるので、電極内部
で部分的に電気抵抗が変化し、電池性能を十分に引き出
すことができない。In the present invention, an easy-adhesion layer containing a conductive filler is provided between the current collector and the active material layer. In the present invention, the average particle diameter of the conductive filler in the easy-adhesion layer is 0.5 μm or less. By specifying such a value, good adhesiveness can be maintained, and a remarkable effect of improving cycle characteristics can be obtained. This is because the conductive filler having an average particle diameter of 0.5 μm or less gives an appropriate surface roughness to the surface of the easily adhesive layer. If the average particle diameter of the conductive filler exceeds 0.5 μm, the surface of the easy-adhesion layer becomes too rough, and the electric contact between the easy-adhesion layer and the active material layer is insufficient and uneven. , The electric resistance is partially changed inside the electrode, and the battery performance cannot be sufficiently obtained.
【００２１】また、本発明においては、易接着層におけ
る導電性フィラーのＤＢＰ吸油量が５０ｍｌ／１００ｇ
以下である。このような値に規定することで、導電性フ
ィラーの導電性を発揮するために、適度な結合剤量での
分散が可能になる。更には、良好な分散状態の導電性フ
ィラーの塗料が得られるので、易接着層の薄膜化が可能
であるばかりでなく、易接着層の表面性のばらつきが小
さくなるため、易接着層と活物質層との間に均一な電気
的接触を保つことができる。一方、導電性フィラーのＤ
ＢＰ吸油量が５０ｍｌ／１００ｇを越えると、導電性フ
ィラーの分散に要する結合剤の割合が多くなり、易接着
層の電気抵抗が高くなり、導電性フィラーの効果を得る
ことができない。In the present invention, the DBP oil absorption of the conductive filler in the easy-adhesion layer is 50 ml / 100 g.
It is the following. By defining such a value, the conductivity of the conductive filler is exhibited, so that the dispersion can be performed with an appropriate amount of the binder. Furthermore, since a coating material of a conductive filler in a good dispersed state can be obtained, not only is it possible to reduce the thickness of the easy-adhesion layer, but also the variation in the surface properties of the easy-adhesion layer reduces the activity of the easy-adhesion layer. A uniform electrical contact can be maintained with the material layer. On the other hand, the conductive filler D
When the BP oil absorption exceeds 50 ml / 100 g, the proportion of the binder required for dispersing the conductive filler increases, the electric resistance of the easily adhesive layer increases, and the effect of the conductive filler cannot be obtained.
【００２２】尚、易接着層中の導電性フィラーと結合剤
との比率は、９５／５〜１０／９０が望ましい。導電性
フィラーと結合剤の比率が９５／５より大きいと，導電
性フィラーの分散が困難になり，１０／９０より小さい
と導電性フィラーの導電性が得られない。さらに、本発
明においては、易接着層の乾燥膜厚が０．０１〜５μｍ
である。ここでいう乾燥膜厚とは、集電体上に易接着塗
料を塗布し，含有溶剤を乾燥させる処理を施した後に測
定した易接着層の膜厚をいう。乾燥膜厚をこのような値
に規定することで、良好な接着性を保ちながら、活物質
層との電気的接触抵抗を低減し、電池の体積エネギー密
度を向上できるという顕著な効果が得られる。易接着層
の乾燥膜厚が０．０１μｍに満たないと、易接着層の機
械的強度が弱く、易接着層に傷が入りやすい。また、易
接着層の乾燥膜厚が５μｍを越えると、易接着層の電気
抵抗が高くなるため、レイト特性やサイクル特性が悪く
なるということがある。また、易接着層を厚膜にするこ
とは、電池の体積エネルギー密度の向上の点からも不利
である。The ratio of the conductive filler to the binder in the easy-adhesion layer is preferably 95/5 to 10/90. If the ratio of the conductive filler to the binder is larger than 95/5, it becomes difficult to disperse the conductive filler, and if it is smaller than 10/90, the conductivity of the conductive filler cannot be obtained. Further, in the present invention, the dry film thickness of the easily adhesive layer is 0.01 to 5 μm.
Is. The dry film thickness as used herein refers to the film thickness of the easy-adhesion layer measured after applying the easy-adhesion coating material on the current collector and drying the contained solvent. By limiting the dry film thickness to such a value, it is possible to obtain a remarkable effect that the electrical contact resistance with the active material layer can be reduced and the volume energy density of the battery can be improved while maintaining good adhesiveness. . If the dry film thickness of the easy-adhesion layer is less than 0.01 μm, the mechanical strength of the easy-adhesion layer is weak and the easy-adhesion layer is easily scratched. If the dry film thickness of the easy-adhesion layer exceeds 5 μm, the electric resistance of the easy-adhesion layer increases, and the rate characteristics and the cycle characteristics may deteriorate. Further, making the easy-adhesion layer a thick film is also disadvantageous in terms of improving the volume energy density of the battery.
【００２３】本発明における導電性フィラーとしては、
導電性金属または金属化合物粉末があげられる。例え
ば、ＡｇやＰｔなどの金属、酸化錫、酸化亜鉛、酸化チ
タンなどの金属化合物、さらには、酸化錫などの金属化
合物にＳｂやＡｌなどをドーピングしたものなどが使用
でき、中でも、分散性の点から酸化錫が好ましい。ま
た、易接着層の結合剤としては、塩化ビニル樹脂、ウレ
タン樹脂などの高分子化合物、さらには、アルカリ金属
系シリケート剤などが使用でき、集電体との反応性の点
からアルカリ金属系シリケート剤が好ましい。尚、導電
性フィラーの分散性を高めるために、易接着層の塗料を
作製する際に、界面活性剤を添加してもよい。As the conductive filler in the present invention,
Examples include conductive metal or metal compound powder. For example, a metal such as Ag or Pt, a metal compound such as tin oxide, zinc oxide or titanium oxide, or a metal compound such as tin oxide doped with Sb or Al can be used. From the viewpoint, tin oxide is preferable. Further, as the binder of the easy-adhesion layer, a polymer compound such as vinyl chloride resin or urethane resin, or an alkali metal silicate agent can be used. Agents are preferred. In addition, in order to improve the dispersibility of the conductive filler, a surfactant may be added when preparing the coating material for the easy-adhesion layer.
【００２４】集電体上への易接着層及び電極活物質層の
形成方法は、特に限定されるものではないが、コンマリ
バ−スコ−ト、スクイ−ズコ−ト、リップコ−ト、ダイ
コート、バーコート、グラビュアコート等の塗布方式が
用いられ、易接着剤、電極活物質が順次形成される。ま
た、上述のように電極、特には正極を形成した後に、活
物質含有層にカレンダ−やプレス処理等で圧力をかけて
もよい。このときの圧力は活物質を形成する材料により
異なるが、一般的には５００〜２０００ｋｇｆ／ｃｍ2
とすればよい。The method for forming the easy-adhesion layer and the electrode active material layer on the current collector is not particularly limited, but may be a comma-bar coat, a squeeze coat, a lip coat, a die coat or a bar. A coating method such as coating or gravure coating is used, and an easy adhesive and an electrode active material are sequentially formed. Further, as described above, after forming the electrode, particularly the positive electrode, pressure may be applied to the active material containing layer by calendering or pressing. The pressure at this time varies depending on the material forming the active material, but is generally 500 to 2000 kgf / cm 2.
And it is sufficient.
【００２５】尚、本発明において、易接着層は正極、負
極いずれに設けても良いが、特には正極に形成すること
が好ましい。次に、ポリマー電解質について説明する。
ポリマー電解質としては、一般的には、ゲル状ポリマー
中に電解液を含有するもの（以下、これを単にポリマー
電解質ということがある）を用いる。In the present invention, the easy-adhesion layer may be provided on either the positive electrode or the negative electrode, but it is particularly preferably formed on the positive electrode. Next, the polymer electrolyte will be described.
As the polymer electrolyte, generally, a gel polymer containing an electrolytic solution (hereinafter, this may be simply referred to as a polymer electrolyte) is used.
【００２６】ゲル状ポリマーに含有させる電解液は非水
電解液が好適であり、これは非水溶媒に電解質を溶解さ
せたものを用いるのが一般的である。ポリマー電解質に
用いる電解液としては、電解質として上記正極活物質及
び負極活物質に対して安定であり、かつリチウムイオン
が前記正極活物質あるいは負極活物質と電気化学反応を
するための移動を行い得る非水物質であればいずれのも
のでも使用することができる。The electrolytic solution contained in the gel polymer is preferably a non-aqueous electrolytic solution, which is generally a non-aqueous solvent in which an electrolyte is dissolved. The electrolytic solution used for the polymer electrolyte is stable to the positive electrode active material and the negative electrode active material as an electrolyte, and lithium ions can move to cause an electrochemical reaction with the positive electrode active material or the negative electrode active material. Any non-aqueous substance can be used.
【００２７】具体的にはＬｉＰＦ6 、ＬｉＡｓＦ6 、Ｌ
ｉＳｂＦ6 、ＬｉＢＦ4 、ＬｉＣｌＯ4 、ＬｉＩ、Ｌｉ
Ｂｒ、ＬｉＣｌ、ＬｉＡｌＣｌ、ＬｉＨＦ2 、ＬｉＳＣ
Ｎ、ＬｉＳＯ3 ＣＦ2 等が挙げられる。これらのうちで
は、特にＬｉＰＦ6 、ＬｉＣｌＯ4 が好適である。これ
ら電解質の電解液における含有量は、一般的に０．５〜
２．５ｍｏｌ／ｌである。Specifically, LiPF 6 , LiAsF 6 , L
iSbF 6 , LiBF 4 , LiClO 4 , LiI, Li
Br, LiCl, LiAlCl, LiHF 2 , LiSC
N, LiSO 3 CF 2, and the like. Of these, LiPF 6 and LiClO 4 are particularly preferable. The content of these electrolytes in the electrolytic solution is generally 0.5 to
It is 2.5 mol / l.
【００２８】このポリマー電解質を溶解する溶媒は特に
限定されないが、比較的高誘電率の溶媒が好適に用いら
れる。具体的にはエチレンカ−ボネ−ト、プロピレンカ
−ボネ−ト等の環状カ−ボネ−ト類、ジメチルカ−ボネ
−ト、ジエチルカ−ボネ−ト、エチルメチルカ−ボネ−
トなどの非環状カ−ボネ−ト類、テトラヒドロフラン、
２−メチルテトラヒドロフラン、ジメトキシエタン等の
グライム類、γ−ブチルラクトン等のラクトン類、スル
フォラン等の硫黄化合物、アセトニトリル等のニトリル
類等の１種又は２種以上の混合物を挙げることができ
る。これらのうちでは、特にエチレンカ−ボネ−ト、プ
ロピレンカ−ボネ−ト等の環状カ−ボネ−ト類、ジメチ
ルカ−ボネ−ト、ジエチルカ−ボネ−ト、エチルメチル
カ−ボネ−トなどの非環状カ−ボネ−ト類から選ばれた
１種又は２種以上の混合溶液が好適である。The solvent for dissolving the polymer electrolyte is not particularly limited, but a solvent having a relatively high dielectric constant is preferably used. Specifically, cyclic carbonates such as ethylene carbonate and propylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate.
Acyclic carbonates such as
One or a mixture of two or more kinds of glymes such as 2-methyltetrahydrofuran and dimethoxyethane, lactones such as γ-butyl lactone, sulfur compounds such as sulfolane, and nitriles such as acetonitrile can be mentioned. Among these, especially cyclic carbonates such as ethylene carbonate and propylene carbonate, non-cyclic carbonates such as dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate and the like. -One or two or more kinds of mixed solutions selected from the carbonates are suitable.
【００２９】上記電解質溶解液をポリエチレンオキサイ
ド、ポリプロピレンオキサイド、ポリエチレンオキサイ
ドのイソシアネ−ト架橋体、フェニレンオキシド、フェ
ニレンスルフィド系ポリマ−等の重合体に浸させゲル状
電解質を作成する。本発明のリチウム二次電池の形状
は、円筒型、箱形、ペ−パ−型、カ−ド型など種々の形
状とすることができる。A gel electrolyte is prepared by immersing the above electrolyte solution in a polymer such as polyethylene oxide, polypropylene oxide, an isocyanate cross-linked product of polyethylene oxide, phenylene oxide or phenylene sulfide polymer. The lithium secondary battery of the present invention can have various shapes such as a cylindrical shape, a box shape, a paper shape, and a card shape.
【００３０】[0030]
【作用】本発明の特徴は上述した如く、ポリマー電解質
を用いたリチウム二次電池において易接着層中の導電性
フィラーの粒子径とＤＢＰ吸油量と、易接着層の乾燥膜
厚を規定することにある。以下、本発明を具体的に説明
する。As described above, the feature of the present invention is to define the particle size of the conductive filler in the easy-adhesion layer, the DBP oil absorption amount, and the dry film thickness of the easy-adhesion layer in the lithium secondary battery using the polymer electrolyte. It is in. Hereinafter, the present invention will be specifically described.
【００３１】[0031]
【実施例】以下に実施例を示し本発明を更に具体的に説
明するが、本発明はその要旨を超えない限り、以下に示
す実施例に制限されるわけではない。なお、各実施例に
おいて評価は下記の方法によって行った。
（接着性）易接着層と正極活物質層との間の接着性は、
電解液に正極を浸漬した時の正極活物質層の剥離に要す
る時間により評価した。電解液にはプロピレンカーボネ
ートを使用し、正極サイズは１３ｍｍΦに成形して評価
した。The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples shown below as long as the gist thereof is not exceeded. In addition, in each Example, the evaluation was performed by the following method. (Adhesiveness) The adhesiveness between the easy-adhesion layer and the positive electrode active material layer is
The time required for peeling the positive electrode active material layer when the positive electrode was immersed in the electrolytic solution was evaluated. Propylene carbonate was used as the electrolytic solution, and the size of the positive electrode was molded to 13 mmΦ for evaluation.
【００３２】（初期放電容量［ｍＡＨ／ｇ］）初期放電
容量は正極重量当たりの放電容量で計算した。評価は同
一のシ−トから５個同じ電池を作成して、初期放電容量
のばらつきも評価した。
（サイクル特性）サイクル特性は初期放電容量を１とし
たとき、容量保持率が８０％以下になったサイクル数で
評価した。評価は同一のシ−トから５個同じ電池を作成
して、サイクル特性のばらつきも評価した。(Initial discharge capacity [mAH / g]) The initial discharge capacity was calculated by the discharge capacity per positive electrode weight. For evaluation, five same batteries were prepared from the same sheet, and the variation in initial discharge capacity was also evaluated. (Cycle characteristics) The cycle characteristics were evaluated by the number of cycles in which the capacity retention rate was 80% or less when the initial discharge capacity was 1. For evaluation, five identical batteries were prepared from the same sheet, and variations in cycle characteristics were also evaluated.
【００３３】実施例１
以下に示す組成に従い易接着層塗料を作成しアルミ基材
上に塗布した。易接着層塗料の原料としては以下のもの
を使用した。
導電性フィラー：酸化錫粉末（三菱マテリアル社製；平均粒子径０．０３μｍ
、ＤＢＰ吸油量３０ｍｌ／１００ｇ） ４０重量部
結合剤 ：Ｌｉ2 Ｓｉ15Ｏ11の２０％水溶液（Ａｌｄｒｉｃｈ社製）
９０重量部
界面活性剤 ：Ｔｒｉｔｏｎ Ｘ−１００（Ａｌｉｄｒｉｃｈ社製）
１重量部
水 ： １５０重量部Example 1 An easy-adhesion layer paint was prepared according to the composition shown below and applied on an aluminum substrate. The following materials were used as the raw materials for the easy-adhesion layer paint. Conductive filler: tin oxide powder (manufactured by Mitsubishi Materials; average particle size 0.03 μm, DBP oil absorption 30 ml / 100 g) 40 parts by weight Binder: 20% aqueous solution of Li 2 Si 15 O 11 (manufactured by Aldrich) 90 parts by weight Parts Surfactant: Triton X-100 (manufactured by Alidrich) 1 part by weight Water: 150 parts by weight
【００３４】上記易接着層用材料の分散処理を行い塗料
化し、厚さ２０μｍのアルミ箔上にバーコーターを用
い、乾燥膜厚が０．０１μｍになるよう塗布した。塗膜
の乾燥条件は，２００℃で９０秒間の予備乾燥後、さら
に、脱水のために４００℃のＡｒ雰囲気の電気炉で２４
時間乾燥させた。続いて、以下に示す組成に従い正極用
塗料を作成し、上記の易接着層付きアルミ基材上に塗布
して、Ｌｉ電池用の正極とし評価した。正極塗料の原料
としては以下のものを使用した。The material for the easy-adhesion layer was subjected to dispersion treatment to form a coating material, which was applied onto an aluminum foil having a thickness of 20 μm using a bar coater so that the dry film thickness was 0.01 μm. The drying conditions of the coating film are as follows: pre-drying at 200 ° C for 90 seconds, and then 24 hours in an electric furnace at 400 ° C in an Ar atmosphere for dehydration.
Allowed to dry for hours. Subsequently, a positive electrode coating material was prepared according to the composition shown below and applied on the above-described aluminum substrate with an easily adhesive layer to evaluate as a positive electrode for a Li battery. The following were used as the raw materials for the positive electrode paint.
【００３５】 正極材 ：ＬｉＣｏＯ2 粉（ＦＭＣ社製） ８８重量部 導電材 ：アセチレンブラック（電気化学工業社製） ４重量部 結合剤 ：Ｐｈｏｔｏｍｅｒ４０５０（Ｈｅｎｋｅｌ社製） ８重量部 溶剤 ：ＤＭＣ（ジメチルカ−ボネ−ト、三菱化学社製）１００重量部 架橋開始剤 ：Ｔｒｉｇｎｏｘ４２（Ａｋｕｚｏ Ｎｏｂｅｌ社製） ０．１重量部Cathode material: LiCoO 2 powder (manufactured by FMC) 88 parts by weight Conductive material: acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.) 4 parts by weight Binder: Photomer 4050 (manufactured by Henkel) 8 parts by weight Solvent: DMC (dimethyl car) Boneto, manufactured by Mitsubishi Chemical Co., Ltd.) 100 parts by weight Crosslinking initiator: Trignox 42 (manufactured by Akzo Nobel) 0.1 part by weight
【００３６】上記正極用材料の混練・分散処理を行い塗
料化し、先に作成した易接着層付きのアルミ箔上にドク
タ−ブレ−ドを用い膜厚が１５０μｍになるよう塗布し
た。その後、塗膜を１２０℃で乾燥・架橋し、電極材が
塗布されたシ−トを得た。次にプレス圧が８００ｋｇｆ
／ｃｍ2 となるようプレス処理を行った。その後、電解
液プロピレンカ−ボネ−トを塗膜に含浸させ、所定の形
状に打ち抜いて正極を作成した。次にここで得られた正
極上に厚さ５０μｍの電解質を塗布し、紫外線架橋を行
ってゲル状電解質層を作成した。ゲル状電解質層上に負
極として金属Ｌｉ箔をラミネ−トし、シ−ト状の電池を
得た。The above positive electrode material was kneaded and dispersed to form a coating material, which was coated on the aluminum foil with the easy-adhesion layer prepared above using a doctor blade so that the film thickness would be 150 μm. Then, the coating film was dried and crosslinked at 120 ° C. to obtain a sheet coated with the electrode material. Next, the press pressure is 800 kgf
The press treatment was performed so that the pressure became / cm 2 . After that, the electrolytic solution propylene carbonate was impregnated into the coating film and punched into a predetermined shape to prepare a positive electrode. Next, an electrolyte having a thickness of 50 μm was applied onto the positive electrode obtained here, and UV crosslinking was performed to form a gel electrolyte layer. A sheet of battery was obtained by laminating a metallic Li foil as a negative electrode on the gel electrolyte layer.
【００３７】実施例２
易接着層の乾燥膜厚を５μｍとした以外は、実施例１と
同様の方法で、シート状の電池を得た。
実施例３
導電性フィラーとして、平均粒子径が０．０１μｍ、Ｄ
ＢＰ吸油量が４５ｍｌ／１００ｇの酸化錫を使用した以
外は、実施例１と同様の方法で、シート状の電池を得
た。Example 2 A sheet-shaped battery was obtained in the same manner as in Example 1, except that the dry film thickness of the easy-adhesion layer was changed to 5 μm. Example 3 As the conductive filler, the average particle diameter is 0.01 μm, D
A sheet-shaped battery was obtained in the same manner as in Example 1 except that tin oxide having a BP oil absorption of 45 ml / 100 g was used.
【００３８】実施例４
導電性フィラーとして、平均粒子径が０．５μｍ、ＤＢ
Ｐ吸油量が２０ｍｌ／１００ｇの酸化錫を使用した以外
は、実施例１と同様の方法で、シート状の電池を得た。
比較例１
易接着層を設けなかった以外は、実施例１と同様の方法
で、シート状の電池を得た。Example 4 A conductive filler having an average particle size of 0.5 μm and DB
A sheet-shaped battery was obtained in the same manner as in Example 1 except that tin oxide having a P oil absorption of 20 ml / 100 g was used. Comparative Example 1 A sheet-shaped battery was obtained in the same manner as in Example 1 except that the easy adhesion layer was not provided.
【００３９】比較例２
易接着層を設けず、研磨剤粒子を固着した研磨布紙でア
ルミ基材を研磨する処理を施した以外は、実施例１と同
様の方法で、シート状の電池を得た。
比較例３
導電性フィラーとして、平均粒子径が６μｍ、ＤＢＰ吸
油量が１２０ｍｌ／１００ｇのグラファイトを使用した
以外は、実施例１と同様の方法で、シート状の電池を得
た。Comparative Example 2 A sheet-like battery was prepared in the same manner as in Example 1 except that the aluminum base material was polished with abrasive cloth paper to which abrasive particles were fixed, without providing an easy-adhesion layer. Obtained. Comparative Example 3 A sheet-shaped battery was obtained in the same manner as in Example 1 except that graphite having an average particle diameter of 6 μm and a DBP oil absorption of 120 ml / 100 g was used as the conductive filler.
【００４０】比較例４
導電性フィラーとして、平均粒子径が６μｍ、ＤＢＰ吸
油量が１２０ｍｌ／１００ｇのグラファイトを使用し、
易接着層の乾燥膜厚を５μｍとした以外は、実施例１と
同様の方法で、シート状の電池を得た。
比較例５
易接着層の乾燥膜厚を１０μｍとした以外は、実施例１
と同様の方法で、シート状の電池を得た。Comparative Example 4 Graphite having an average particle size of 6 μm and a DBP oil absorption of 120 ml / 100 g was used as a conductive filler.
A sheet-shaped battery was obtained in the same manner as in Example 1 except that the dry film thickness of the easy-adhesion layer was 5 μm. Comparative Example 5 Example 1 except that the dry film thickness of the easy-adhesion layer was 10 μm.
A sheet-shaped battery was obtained in the same manner as in.
【００４１】比較例６
易接着層の乾燥膜厚を０．００５μｍとした以外は、実
施例１と同様の方法で、シート状の電池を得た。
比較例７
導電性フィラーとして、平均粒子径が１．０μｍ、ＤＢ
Ｐ吸油量が１５ｍｌ／１００ｇの酸化錫を使用した以外
は、実施例１と同様の方法で、シート状の電池を得た。Comparative Example 6 A sheet-shaped battery was obtained in the same manner as in Example 1 except that the dry film thickness of the easy-adhesion layer was 0.005 μm. Comparative Example 7 As the conductive filler, the average particle size was 1.0 μm, DB
A sheet-shaped battery was obtained in the same manner as in Example 1 except that tin oxide having a P oil absorption of 15 ml / 100 g was used.
【００４２】比較例８
導電性フィラーとして、平均粒子径が０．００５μｍ、
ＤＢＰ吸油量が６０ｍｌ／１００ｇの酸化錫を使用した
以外は、実施例１と同様の方法で、シート状の電池を得
た。
実施例１〜３および比較例１〜８について、接着性、初
期放電容量、サイクル特性を評価し、その結果を表１に
示す。Comparative Example 8 As the conductive filler, the average particle size is 0.005 μm,
A sheet-shaped battery was obtained in the same manner as in Example 1 except that tin oxide having a DBP oil absorption of 60 ml / 100 g was used. With respect to Examples 1 to 3 and Comparative Examples 1 to 8, the adhesiveness, initial discharge capacity, and cycle characteristics were evaluated, and the results are shown in Table 1.
【００４３】[0043]
【表１】 表１ 接着性 初期放電容量 サイクル特性 （ｍＡｈ／ｇ） （サイクル） 実施例１ ２４時間で剥離なし １２５±２ ３００以上 実施例２ ２４時間で剥離なし １２３±２ ３００以上 実施例３ ２０時間で剥離 １１７±５ ３００±７ 実施例４ １８時間で剥離 １１５±６ ２８０±９ 比較例１ １分で剥離 １２２±５ ３０±２０ 比較例２ ２０分で剥離 １１９±１５ ５０±１８ 比較例３ ６時間で剥離 １１５±１２ １００±１０ 比較例４ ６時間で剥離 １１３±１８ １００±１８ 比較例５ １８時間で剥離 １０８±１０ １８０±１８ 比較例６ ２０時間で剥離 １１８±１８ ２００±２０ 比較例７ １０時間で剥離 １０５±１４ １５０±２０ 比較例８ ８時間で剥離 １１０±１８ １２０±２３[Table 1] Table 1 Adhesion Initial discharge capacity Cycle characteristics (MAh / g) (Cycle) Example 1 No peeling in 24 hours 125 ± 2 300 or more Example 2 No peeling in 24 hours 123 ± 2 300 or more Example 3 Peeling off in 20 hours 117 ± 5 300 ± 7 Example 4 Peeling off in 18 hours 115 ± 6 280 ± 9 Comparative Example 1 Peeling off in 1 minute 122 ± 5 30 ± 20 Comparative Example 2 Peeling off in 20 minutes 119 ± 15 50 ± 18 Comparative Example 3 Peeling off in 6 hours 115 ± 12 100 ± 10 Comparative Example 4 Peeling off in 6 hours 113 ± 18 100 ± 18 Comparative Example 5 Peeling off in 18 hours 108 ± 10 180 ± 18 Comparative Example 6 Peeling off in 20 hours 118 ± 18 200 ± 20 Comparative Example 7 Peeling off within 10 hours 105 ± 14 150 ± 20 Comparative Example 8 Peeling off in 8 hours 110 ± 18 120 ± 23
【００４４】[0044]
【発明の効果】本発明の易接着層を用いたリチウム電池
は、良好な接着性が得られ、電池の性能のばらつきが少
なく、サイクル特性に優れた電池となる。INDUSTRIAL APPLICABILITY The lithium battery using the easy-adhesion layer of the present invention has good adhesiveness, has less variation in battery performance, and has excellent cycle characteristics.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平10−308222（ＪＰ，Ａ) 特開 平７−138609（ＪＰ，Ａ) 特開 平７−201363（ＪＰ，Ａ) 特開 平７−201362（ＪＰ，Ａ) 特開 平９−97625（ＪＰ，Ａ) 特開 平10−144298（ＪＰ，Ａ) 特開 平９−22700（ＪＰ，Ａ) 特開 平８−130015（ＪＰ，Ａ) 特開 平10−199524（ＪＰ，Ａ) 特開 平10−208740（ＪＰ，Ａ) 特開 平10−284129（ＪＰ，Ａ) 特表 平11−505660（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/02 - 4/04 H01M 4/38 - 4/62 H01M 10/40 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-10-308222 (JP, A) JP-A-7-138609 (JP, A) JP-A-7-201363 (JP, A) JP-A-7- 201362 (JP, A) JP 9-97625 (JP, A) JP 10-144298 (JP, A) JP 9-22700 (JP, A) JP 8-130015 (JP, A) JP-A-10-199524 (JP, A) JP-A-10-208740 (JP, A) JP-A-10-284129 (JP, A) Special Table 11-505660 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) H01M 4/02-4/04 H01M 4/38-4/62 H01M 10/40
Claims (4)
接着層を施した電極を用いたリチウム二次電池におい
て、該易接着層中に、平均粒子径が０．５μｍ以下かつ
ＤＢＰ吸油量が５０ｍｌ／１００ｇ以下の導電性フィラ
ー及び界面活性剤を含み、該易接着層の乾燥膜厚が０．
０１〜５μｍであることを特徴とするリチウム二次電
池。1. A lithium secondary battery using an electrode in which an easy-adhesion layer is provided between a foil-shaped current collector and a battery active material layer, wherein the easy-adhesion layer has an average particle size of 0.5 μm. Or less and a DBP oil absorption of 50 ml / 100 g or less, which contains a conductive filler and a surfactant, and the dry film thickness of the easily adhesive layer is 0.
A lithium secondary battery having a thickness of 01 to 5 μm.
徴とする請求項１記載のリチウム二次電池。2. The lithium secondary battery according to claim 1, wherein the conductive filler is tin oxide.
リチウム二次電池であって、正極が、箔状の正極集電体
上に易接着層、リチウムイオンを吸蔵放出可能な化合物
を含む正極活物質層を順次設けたものであり、該易接着
層中に平均粒子径が０．５μｍ以下、ＤＢＰ吸油量が５
０ｍｌ／１００ｇ以下の導電性フィラーを含み、かつ該
易接着層の乾燥膜厚が０．０１〜５μｍであることを特
徴とするリチウム二次電池。3. A lithium secondary battery comprising a positive electrode, a negative electrode and a polymer electrolyte, wherein the positive electrode comprises a foil-shaped positive electrode current collector, an easy-adhesion layer, and a compound capable of inserting and extracting lithium ions. The material layers are sequentially provided, and the easy-adhesion layer has an average particle size of 0.5 μm or less and a DBP oil absorption of 5
A lithium secondary battery comprising 0 ml / 100 g or less of a conductive filler and having a dry film thickness of the easily adhesive layer of 0.01 to 5 μm.
状ポリマーからなる電解質であることを特徴とする請求
項３記載のリチウム二次電池。4. The lithium secondary battery according to claim 3, wherein the polymer electrolyte is an electrolyte made of a gel polymer containing a non-aqueous electrolyte solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22466997A JP3478077B2 (en) | 1997-08-21 | 1997-08-21 | Lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22466997A JP3478077B2 (en) | 1997-08-21 | 1997-08-21 | Lithium secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1167277A JPH1167277A (en) | 1999-03-09 |
| JP3478077B2 true JP3478077B2 (en) | 2003-12-10 |
Family
ID=16817368
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22466997A Expired - Lifetime JP3478077B2 (en) | 1997-08-21 | 1997-08-21 | Lithium secondary battery |
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| Country | Link |
|---|---|
| JP (1) | JP3478077B2 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1164003A (en) * | 1997-06-13 | 1999-03-05 | Denso Corp | Angular velocity sensor |
| KR100354249B1 (en) * | 2000-01-06 | 2002-09-28 | 삼성에스디아이 주식회사 | Lithium polymer battery |
| KR100402955B1 (en) * | 2001-03-26 | 2003-10-30 | 대한민국(관리청:특허청장, 승계청:경상대학교총장) | Inorganic Ceramic Filler for Composite Polymer Electrolyte in Lithium Polymer Batteries and Polymer Electrolyte Comprising the Same |
| JP2004296863A (en) * | 2003-03-27 | 2004-10-21 | Tdk Corp | Electrode for electrochemical capacitor and manufacturing method thereof, and electrochemical capacitor and manufacturing method thereof |
| CN1768404B (en) * | 2003-03-31 | 2013-01-09 | 富士重工业株式会社 | Organic electrolyte capacitor |
| WO2010084622A1 (en) * | 2009-01-26 | 2010-07-29 | トヨタ自動車株式会社 | Positive electrode for lithium secondary battery and use thereof |
| JP2015109214A (en) * | 2013-12-05 | 2015-06-11 | 株式会社豊田自動織機 | Collector and lithium ion secondary battery |
| JP6486867B2 (en) * | 2016-06-02 | 2019-03-20 | 太陽誘電株式会社 | Electrode for electrochemical device and method for producing electrode for electrochemical device |
| CN112186195B (en) | 2019-07-01 | 2023-11-03 | 宁德时代新能源科技股份有限公司 | Positive electrode plate and electrochemical device |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07138609A (en) * | 1993-09-14 | 1995-05-30 | Katayama Tokushu Kogyo Kk | Metallic porous body and its production |
| JP3441141B2 (en) * | 1993-12-29 | 2003-08-25 | Ｔｄｋ株式会社 | Lithium secondary battery |
| JP3229740B2 (en) * | 1993-12-29 | 2001-11-19 | ティーディーケイ株式会社 | Lithium secondary battery |
| US5478676A (en) * | 1994-08-02 | 1995-12-26 | Rexam Graphics | Current collector having a conductive primer layer |
| JPH08130015A (en) * | 1994-10-27 | 1996-05-21 | Mitsubishi Cable Ind Ltd | Negative electrode material, its negative electrode, and lithium secondary battery |
| JPH0922700A (en) * | 1995-07-06 | 1997-01-21 | Toshiba Battery Co Ltd | Polymer electrolyte secondary battery |
| JPH0997625A (en) * | 1995-09-29 | 1997-04-08 | Seiko Instr Inc | Nonaqueous electrolytic secondary battery and manufacture thereof |
| JPH10144298A (en) * | 1996-11-15 | 1998-05-29 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JP3620559B2 (en) * | 1997-01-17 | 2005-02-16 | 株式会社ユアサコーポレーション | Non-aqueous electrolyte battery |
| JP3653717B2 (en) * | 1997-01-24 | 2005-06-02 | 株式会社ユアサコーポレーション | Non-aqueous electrolyte battery |
| JP4161383B2 (en) * | 1997-04-10 | 2008-10-08 | 株式会社ジーエス・ユアサコーポレーション | Nonaqueous electrolyte secondary battery |
| JPH10308222A (en) * | 1997-05-07 | 1998-11-17 | Nippon Glass Fiber Co Ltd | Positive electrode for lithium secondary battery, and lithium secondary battery using thereof |
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1997
- 1997-08-21 JP JP22466997A patent/JP3478077B2/en not_active Expired - Lifetime
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