JPH11312516A - Positive electrode for lithium secondary battery and lithium secondary battery using the same - Google Patents
Positive electrode for lithium secondary battery and lithium secondary battery using the sameInfo
- Publication number
- JPH11312516A JPH11312516A JP10118502A JP11850298A JPH11312516A JP H11312516 A JPH11312516 A JP H11312516A JP 10118502 A JP10118502 A JP 10118502A JP 11850298 A JP11850298 A JP 11850298A JP H11312516 A JPH11312516 A JP H11312516A
- Authority
- JP
- Japan
- Prior art keywords
- positive electrode
- conductive adhesive
- secondary battery
- lithium secondary
- adhesive layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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
Landscapes
- Cell Electrode Carriers And Collectors (AREA)
- 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、リチウムイオンを
吸蔵放出することのできるリチウム二次電池用正極及び
この正極を用いたリチウム二次電池に係わり、詳しく
は、活物質層と集電体との接合性の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive electrode for a lithium secondary battery capable of inserting and extracting lithium ions and a lithium secondary battery using the positive electrode. More specifically, the present invention relates to an active material layer and a current collector. The improvement of the bondability of the steel.
【０００２】[0002]
【従来の技術】従来、リチウム二次電池の正極、負極の
作製は、正負極活物質、導電材、バインダーを有機溶媒
でスラリー化して合材となし、この合材を集電体上に塗
布乾燥後、所定の電極厚み、電極幅に加工するため圧
延、切断を行い、正負極が準備されていた。そして、こ
の正負極を、セパレータを介して円柱状に巻き取り、電
極群を作製し、電池組み立てを行っている。特に、大型
電池の場合、長尺幅広の電極を作製する必要があるが、
上述した従来の作製方法では、充放電サイクル中に電極
活物質の脱落等により、サイクル寿命が低下する傾向が
あった。2. Description of the Related Art Conventionally, a positive electrode and a negative electrode of a lithium secondary battery have been manufactured by forming a positive and negative electrode active material, a conductive material, and a binder into a slurry by using an organic solvent to form a mixture, and applying the mixture to a current collector. After drying, rolling and cutting were performed in order to process to a predetermined electrode thickness and electrode width, and positive and negative electrodes were prepared. Then, the positive and negative electrodes are wound into a column shape through a separator, an electrode group is produced, and a battery is assembled. In particular, in the case of a large battery, it is necessary to produce a long and wide electrode,
In the above-described conventional manufacturing method, the cycle life tends to be reduced due to dropout of the electrode active material during the charge / discharge cycle.
【０００３】そこで、ステンレスからなる帯状の正極集
電体の表裏両面に金メッキ処理を施した後、この集電体
上にポりビニルブチラールをバインダーとした正極合剤
層を成形し、300℃の熱処理によってこのバインダーを
分解除去する正極製造法が試みられている（例えば、特
開平9-120814号公報を参照）。しかしながら、バインダ
ーを除去するための300℃の熱処理工程が必要であっ
て、製造工程が煩雑である。また、金メッキ処理により
活物質層と集電体間の電気的接触が改善され、負荷特性
が向上するが、活物質層中のバインダーが除去されるの
で、電池のサイクル経過に伴い、活物質の脱落に起因す
るサイクル寿命の低下が問題であった。[0003] Therefore, after a gold plating treatment is applied to both the front and back surfaces of a belt-shaped positive electrode current collector made of stainless steel, a positive electrode mixture layer using polyvinyl butyral as a binder is formed on the current collector, and the mixture is heated to 300 ° C. Attempts have been made to produce a positive electrode in which this binder is decomposed and removed by heat treatment (for example, see JP-A-9-208814). However, a heat treatment step at 300 ° C. for removing the binder is required, and the manufacturing process is complicated. The gold plating improves the electrical contact between the active material layer and the current collector and improves the load characteristics.However, the binder in the active material layer is removed. The problem was that the cycle life was shortened due to the falling off.
【０００４】また、集電体と合剤層との接着強度を高
め、充放電サイクル特性を向上させることを目的とし
て、集電体と合剤層との間にフッ素樹脂、変性ゴム等の
接着樹脂を介在させる試みがなされている（例えば特開
平9-306473号公報参照）。しかしながら、この方法では
集電体と合剤層間の電気伝導性を低下させてしまうの
で、電池性能が十分に発揮できない。Further, in order to increase the adhesive strength between the current collector and the mixture layer and to improve the charge / discharge cycle characteristics, an adhesive such as a fluororesin or a modified rubber is provided between the current collector and the mixture layer. Attempts have been made to interpose a resin (see, for example, JP-A-9-306473). However, this method lowers the electrical conductivity between the current collector and the mixture layer, so that the battery performance cannot be sufficiently exhibited.
【０００５】[0005]
【発明が解決しようとする課題】本発明はかかる知見に
基づきなされたものであって、その目的とするところは
活物質層と集電体間の良好な電気的接触を保ち、且つ活
物質層と集電体との密着性を向上させようとするもので
ある。DISCLOSURE OF THE INVENTION The present invention has been made based on such findings, and an object of the present invention is to maintain good electrical contact between an active material layer and a current collector and to provide an active material layer. And a current collector.
【０００６】また、このようなリチウム二次電池用の正
極を用いることによって、優れた充放電サイクル特性を
有するリチウム二次電池を提供することである。Another object of the present invention is to provide a lithium secondary battery having excellent charge / discharge cycle characteristics by using such a positive electrode for a lithium secondary battery.
【０００７】[0007]
【課題を解決するための手段】本発明は、リチウムイオ
ンの吸蔵、放出可能な正極材料と結着材とからなる正極
合材層を、集電体上に配置したリチウム二次電池用正極
において、前記正極合材層と前記集電体との間に、導電
性接着層を配置したことを特徴とする。The present invention relates to a positive electrode for a lithium secondary battery in which a positive electrode mixture layer comprising a positive electrode material capable of absorbing and releasing lithium ions and a binder is disposed on a current collector. A conductive adhesive layer is disposed between the positive electrode mixture layer and the current collector.
【０００８】前記導電性接着層には、導電性を向上させ
るために、銀、ニッケル及び炭素よりなる群から選択さ
れた少なくとも一つの導電材料が含有されていることを
特徴とする。[0008] The conductive adhesive layer contains at least one conductive material selected from the group consisting of silver, nickel and carbon in order to improve conductivity.
【０００９】また、前記導電性接着層は、前記集電体の
両面に配置することができる。この導電性接着層を構成
する材料としては、以下の実施例で例示するポリフッ化
ビニリデン（ＰＶｄＦ）、ポリイミド（ＰＩ）系樹脂、
ＳＢＲに代表されるスチレンーブタジエン系樹脂、ポリ
プロピレンやポリエチレンに代表されるポリオレフィン
系樹脂が例示できる。これらを使用するのは、電解液を
構成する有機溶媒中においても安定に存在するためであ
る。Further, the conductive adhesive layer can be disposed on both sides of the current collector. Examples of a material constituting the conductive adhesive layer include polyvinylidene fluoride (PVdF), a polyimide (PI) resin exemplified in the following examples,
Examples thereof include a styrene-butadiene-based resin represented by SBR and a polyolefin-based resin represented by polypropylene and polyethylene. These are used because they are stably present in the organic solvent constituting the electrolytic solution.
【００１０】ここで、前記導電材料の含有量としては、
前記導電性接着層の重量に対して、2.0〜20.0重量％と
することによって、また、導電性接着層の厚みを3.0〜1
0.0μｍの範囲とすることによって、初期放電容量、容
量維持率が高いままに維持可能である。尚、本発明にお
いて使用可能な導電材料の平均粒径は0.5μｍ〜3.0μｍ
程度である。Here, the content of the conductive material is as follows:
By setting the weight of the conductive adhesive layer to 2.0 to 20.0% by weight, the thickness of the conductive adhesive layer is set to 3.0 to 1%.
By setting the thickness in the range of 0.0 μm, it is possible to maintain the initial discharge capacity and the capacity retention rate as high. The average particle size of the conductive material usable in the present invention is 0.5 μm to 3.0 μm.
It is about.
【００１１】尚、本発明における正極の厚みとしては集
電体も含めて、50μｍ〜200μｍ程度のものが適する。
また、集電体の厚みとしては、10μｍ〜20μｍ程度のも
のが使用される。In the present invention, the thickness of the positive electrode, including the current collector, is preferably about 50 μm to 200 μm.
The thickness of the current collector is about 10 μm to 20 μm.
【００１２】そして、前記リチウムイオンの吸蔵、放出
可能な正極材料としては、金属酸化物が、それ自身が導
電性が高くないという観点から、適するものである。具
体的には、LiCOO2、LiNiO2、LiCO1-xNixO2、LiMn2O4及
びこれらの複合化物からなる群から選択された少なくと
も1種の材料を挙げることができる。As the positive electrode material capable of inserting and extracting lithium ions, a metal oxide is suitable from the viewpoint that the metal oxide itself does not have high conductivity. Specifically, at least one material selected from the group consisting of LiCOO 2 , LiNiO 2 , LiCO 1-x Ni x O 2 , LiMn 2 O 4 and a composite thereof can be used.
【００１３】更に、上述したリチウム二次電池用正極を
備えたリチウム二次電池を準備することによって、初期
放電容量、容量維持率が高い電池が提供できる。Further, by preparing a lithium secondary battery having the above-mentioned positive electrode for a lithium secondary battery, a battery having a high initial discharge capacity and a high capacity retention rate can be provided.
【００１４】以上の説明では、導電性接着層を正極に設
けたものについて言及しているが、炭素材料からなる負
極に用いることも可能である。In the above description, reference is made to the case where the conductive adhesive layer is provided on the positive electrode. However, the present invention can also be used for a negative electrode made of a carbon material.
【００１５】尚、本発明のリチウム二次電池で使用され
る負極としては、黒鉛、コークスなどの炭素材料、リチ
ウム金属、リチウム合金、LixFe2O3、LixWO2等の金属酸
化物負極、ポリアセチレン等の導電性高分子負極等が挙
げられる。特に黒鉛からなる炭素材料を負極に用いた場
合、優れた効果が発揮される。前記炭素材料に用いられ
る黒鉛、コークス材料としては、粉砕したものをそのま
ま用いてもよく、加熱処理（500〜3700℃）したものを
用いてもよい。また、黒鉛のd002値は3.35〜3.37Å、Lc
は400Å以上が好ましい。The negative electrode used in the lithium secondary battery of the present invention includes carbon materials such as graphite and coke, lithium metal, lithium alloys, metal oxide negative electrodes such as LixFe 2 O 3 and LixWO 2 and polyacetylene. And the like. In particular, when a carbon material made of graphite is used for the negative electrode, excellent effects are exhibited. As the graphite and coke material used for the carbon material, a crushed material may be used as it is, or a heat-treated (500 to 3700 ° C.) material may be used. The d 002 value of graphite is 3.35 to 3.37Å, Lc
Is preferably 400 ° or more.
【００１６】そして、電解液、電解質、セパレータなど
の電池構成部材についても、従来リチウム二次電池用と
して実用され或いは提案されている種々の材料を、特に
制限なく使用することが可能である。Various materials conventionally used or proposed for lithium secondary batteries can be used without particular limitation for battery components such as an electrolytic solution, an electrolyte, and a separator.
【００１７】例えば、電解質としてはリチウムイオン等
の金属イオンを含むLiPF6、LiClO4、LiCF3SO3などの電
解質が例示される。また、電解液の有機溶媒としてはエ
チレンカーボネート、ジエチルカーボネート、ジメトキ
シメタン、スルホラン等を単独で、あるいは混合して用
いることができる。電解液としてはこれら溶媒に前記電
解質を0.7〜1.5Ｍ（mol／l）程度の割合で溶解させた溶
液が例示される。For example, examples of the electrolyte include electrolytes such as LiPF 6 , LiClO 4 , and LiCF 3 SO 3 containing metal ions such as lithium ions. Further, as the organic solvent of the electrolytic solution, ethylene carbonate, diethyl carbonate, dimethoxymethane, sulfolane, or the like can be used alone or in combination. Examples of the electrolyte include a solution in which the electrolyte is dissolved in these solvents at a ratio of about 0.7 to 1.5 M (mol / l).
【００１８】[0018]
【発明の実施の形態】以下、本発明を実施例に基づいて
更に詳細に説明するが、本発明は下記実施例に何ら限定
されるものではなく、その要旨を変更しない範囲におい
て適宜変更して実施することが可能なものである。 （実験１）まず、この実験１では、導電性接着層に含有
させる導電材料の有無、及び種類を代えて、電池特性に
及ぼす影響を調べた。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples at all, and may be modified as appropriate without departing from the gist thereof. It can be implemented. (Experiment 1) First, in Experiment 1, the influence on the battery characteristics was examined by changing the presence or absence and the type of the conductive material to be contained in the conductive adhesive layer.
【００１９】<実施例1>正極の作製は、以下の手順で行
った。Example 1 A positive electrode was produced in the following procedure.
【００２０】導電材料としての銀粉末を含有した、ポリ
フッ化ビニリデン（ＰＶｄＦ）をN-メチル-2-ピロリド
ン（ＮＭＰ）に分散させたスラリーを、正極集電体であ
るアルミニウム箔（厚みは20μｍ）の両面に5.0μｍの
厚さで塗布した後、乾燥した。ここで、導電材料の銀粉
末は、導電性接着層の乾燥重量に対して10.0重量％含有
されている。この銀粉末の平均粒径は約1.0μｍであ
る。A slurry containing polyvinylidene fluoride (PVdF) containing silver powder as a conductive material and dispersed in N-methyl-2-pyrrolidone (NMP) was used as an aluminum foil (thickness: 20 μm) as a positive electrode current collector. Was coated at a thickness of 5.0 μm on both sides and dried. Here, the silver powder of the conductive material is contained at 10.0% by weight based on the dry weight of the conductive adhesive layer. The average particle size of the silver powder is about 1.0 μm.
【００２１】次に、正極活物質即ち正極材料としてのLi
CoO2は、リチウムの水酸化物とコバルトの水酸化物を混
合し、空気中で800℃で24時間焼成することにより得た
ものである。この正極材料と導電材としての人造黒鉛を
重量比90：５で混合し、正極合剤を作製した。そして、
結着剤であるＰＶｄＦをＮＭＰに溶解させ、ＮＭＰ溶液
を調整した。正極合剤とポリフッ化ビニリデンの重量比
が95：５になるよう正極合剤とＮＭＰ溶液を混練してス
ラリーを調整し、このスラリーを上記の導電性接着層を
配設した正極集電体アルミニウム箔の両面に、ドクター
ブレード法により塗布、接着し、150℃で２時間真空乾
燥して、本発明に係わる正極を作製した。Next, as a positive electrode active material, that is, Li as a positive electrode material,
CoO 2 is obtained by mixing a hydroxide of lithium and a hydroxide of cobalt and calcining the mixture at 800 ° C. for 24 hours in the air. This positive electrode material and artificial graphite as a conductive material were mixed at a weight ratio of 90: 5 to prepare a positive electrode mixture. And
PVdF as a binder was dissolved in NMP to prepare an NMP solution. A slurry is prepared by kneading the positive electrode mixture and the NMP solution so that the weight ratio of the positive electrode mixture and polyvinylidene fluoride becomes 95: 5, and the slurry is mixed with the positive electrode current collector aluminum provided with the conductive adhesive layer. The foil was applied and adhered to both sides of the foil by a doctor blade method, and dried under vacuum at 150 ° C. for 2 hours to produce a positive electrode according to the present invention.
【００２２】ここで、図１に、本発明に係るリチウム二
次電池用正極の模式的断面図を示す。図１において、11
は正極集電体、12は導電性接着層、13は正極合材層を表
わしている。Here, FIG. 1 shows a schematic sectional view of the positive electrode for a lithium secondary battery according to the present invention. In FIG. 1, 11
Denotes a positive electrode current collector, 12 denotes a conductive adhesive layer, and 13 denotes a positive electrode mixture layer.
【００２３】また、負極は次のようにして準備した。負
極材料として、炭素塊（d002＝3.356Å；Lc＞1000Å）
に空気流を噴射、粉砕（ジェット粉砕）してふるいにか
け、粒子径10μｍの黒鉛粉末を得た。また結着剤である
ポリフッ化ビニリデンをＮＭＰに溶解させ、ＮＭＰ溶液
を調整した。この炭素粉末とポリフッ化ビニリデンの重
量比が90：10になるよう混練してスラリーを調製した。
このスラリーを負極集電体としての銅箔の両面にドクタ
ーブレード法により塗布し、150℃で２時間真空乾燥し
て負極を作製した。この負極の厚みは、集電体も含め
て、150μｍであった。The negative electrode was prepared as follows. As a negative electrode material, carbon lump (d 002 = 3.356Å; Lc> 1000Å)
An air stream was jetted, pulverized (jet pulverized) and sieved to obtain a graphite powder having a particle diameter of 10 μm. In addition, polyvinylidene fluoride as a binder was dissolved in NMP to prepare an NMP solution. A slurry was prepared by kneading the carbon powder and polyvinylidene fluoride so that the weight ratio was 90:10.
This slurry was applied to both surfaces of a copper foil as a negative electrode current collector by a doctor blade method, and vacuum dried at 150 ° C. for 2 hours to produce a negative electrode. The thickness of this negative electrode including the current collector was 150 μm.
【００２４】そして、電解液としては、エチレンカーボ
ネートとジメトキシメタンを体積比1：1で混合した溶媒
に、 LiPF6を１Ｍの割合で溶解して電解液を調製した。As an electrolytic solution, LiPF6 was dissolved at a ratio of 1M in a solvent in which ethylene carbonate and dimethoxymethane were mixed at a volume ratio of 1: 1 to prepare an electrolytic solution.
【００２５】以上の正、負極及び電解液のほか、ポリプ
ロピレン製の微多孔性薄膜からなるセパレータなどを用
いて小型円筒型リチウム二次電池Ａ１を作製した。この
電池の寸法は、直径14.2mm、高さ50.0mmである。A small cylindrical lithium secondary battery A1 was fabricated using the positive electrode, the negative electrode, the electrolytic solution, and a separator made of a polypropylene microporous thin film. The dimensions of this battery are 14.2 mm in diameter and 50.0 mm in height.
【００２６】図２に、本発明リチウム二次電池の断面図
を示す。図２において電池Ａ１は、正極１、負極２、こ
れらの両電極を隔離するセパレータ３、アルミ製の正極
リード４、ニッケル製の負極リード５、正極外部端子
６、及び負極缶７からなる。FIG. 2 is a sectional view of the lithium secondary battery of the present invention. In FIG. 2, a battery A1 includes a positive electrode 1, a negative electrode 2, a separator 3 for separating these two electrodes, an aluminum positive electrode lead 4, a nickel negative electrode lead 5, a positive electrode external terminal 6, and a negative electrode can 7.
【００２７】＜実施例２＞導電性接着層において、導電
材料としての銀粉末に代えて、ニッケル粉末を用いた以
外は上記実施例1と同様にして、本発明電池Ａ２を作製
した。<Example 2> A battery A2 of the present invention was produced in the same manner as in Example 1 except that nickel powder was used instead of silver powder as the conductive material in the conductive adhesive layer.
【００２８】＜実施例３＞導電性接着層において、導電
材料としての銀粉末に代えて、人造黒鉛を用いた以外は
上記実施例1と同様にして、本発明電池Ａ３を作製し
た。Example 3 A battery A3 of the present invention was produced in the same manner as in Example 1 except that artificial graphite was used instead of silver powder as a conductive material in the conductive adhesive layer.
【００２９】＜比較例＞導電性接着層を配設せず、集電
体上に活物質層を直接塗布すること以外は、上記実施例
１と同様にして、比較電池Ｘを組み立てた。<Comparative Example> A comparative battery X was assembled in the same manner as in Example 1 except that the active material layer was directly applied on the current collector without providing the conductive adhesive layer.
【００３０】これらの本発明電池Ａ１〜電池Ａ３及び比
較電池Ｘを用いて、電池の初期放電容量と100サイクル
目の容量維持率を測定した。実験条件は、各電池を１Ｃ
の充放電率で電池電圧4.2Ｖまで充電した後、2.7Ｖに至
るまで放電する工程を1サイクルとする充放電サイクル
試験を行い、100サイクル目の容量維持率を求めた。こ
こで、100サイクル目の容量維持率は次のように算出し
ている。 ［100サイクル目の容量維持率（％）＝（100サイクル目
の放電容量／１サイクル目の放電容量）×100］ この結果を、表1に示す。Using the batteries A1 to A3 of the present invention and the comparative battery X, the initial discharge capacity of the battery and the capacity retention ratio at the 100th cycle were measured. The experiment conditions were as follows:
The battery was charged to a battery voltage of 4.2 V at a charge / discharge rate of, and a charge / discharge cycle test was performed in which the process of discharging to a voltage of 2.7 V was defined as one cycle. Here, the capacity maintenance ratio at the 100th cycle is calculated as follows. [100th cycle capacity retention rate (%) = (100th cycle discharge capacity / first cycle discharge capacity) × 100] The results are shown in Table 1.
【００３１】[0031]
【表１】 [Table 1]
【００３２】表１から、導電性接着層を配設しない比較
電池Ｘの初期放電容量は510mAh、100サイクル目の容量
維持率は80％であることが読み取れる。これに対し、本
発明電池Ａ１、Ａ２、Ａ３は、初期放電容量、100サイ
クル目の容量維持率が大きく、導電性接着層の有効性が
伺える。 （実験２）この実験２では、導電性接着層における導電
材料の添加含有量、即ち銀の含有量を変化させて、その
電池特性に及ぼす影響を調べた。From Table 1, it can be seen that the initial discharge capacity of the comparative battery X without the conductive adhesive layer was 510 mAh, and the capacity retention at the 100th cycle was 80%. On the other hand, the batteries A1, A2, and A3 of the present invention have a large initial discharge capacity and a large capacity retention rate at the 100th cycle, indicating the effectiveness of the conductive adhesive layer. (Experiment 2) In Experiment 2, the content of the conductive material in the conductive adhesive layer, that is, the content of silver was changed, and the effect on the battery characteristics was examined.
【００３３】導電性接着層において、銀粉末の含有量が
それぞれ1.0重量％、2.0重量％、10.0重量％、20.0重量
％、30.0重量％であること以外は上記実施例1と同様に
して本発明電池Ｂ１〜Ｂ５を作製した。The present invention was carried out in the same manner as in Example 1 except that the content of the silver powder in the conductive adhesive layer was 1.0% by weight, 2.0% by weight, 10.0% by weight, 20.0% by weight, and 30.0% by weight, respectively. Batteries B1 to B5 were produced.
【００３４】このようにして、作製した電池を、上記実
験１と同様にして、電池特性を調べた。実験条件は、上
記実験１と同一である。The battery thus manufactured was examined for battery characteristics in the same manner as in Experiment 1. The experimental conditions are the same as in Experiment 1 described above.
【００３５】この結果を、表２に示す。この表２には、
上記実験１で使用した電池Ａ１の結果も併せて示してあ
る。Table 2 shows the results. In Table 2,
The results for the battery A1 used in Experiment 1 are also shown.
【００３６】[0036]
【表２】 [Table 2]
【００３７】この表２より、導電材料である銀粉末の添
加、含有量が1.0重量％以下では初期放電容量の低下、
また30.0重量％以上では100サイクル目の容量維持率の
低下が観察される。従って、導電性接着層への導電材料
の添加は2.0〜20．0重量％の範囲が望ましいことがわか
った。From Table 2, it can be seen that when the addition and content of silver powder as a conductive material is 1.0% by weight or less, the initial discharge capacity decreases.
At 30.0% by weight or more, a decrease in the capacity retention at the 100th cycle is observed. Therefore, it was found that the addition of the conductive material to the conductive adhesive layer was desirably in the range of 2.0 to 20.0% by weight.
【００３８】この添加、含有量の傾向は、銀以外の、ニ
ッケル及び炭素においても、同様に観察される。 （実験３）この実験３では、導電性接着層の厚みを変化
させて、電池特性に及ぼす影響を調べた。This tendency of addition and content is similarly observed in nickel and carbon other than silver. (Experiment 3) In Experiment 3, the effect on the battery characteristics was examined by changing the thickness of the conductive adhesive layer.
【００３９】導電材料として銀粉末を含有した導電性接
着層の厚みが、それぞれ2.0μｍ、3.0μｍ、10.0μｍ、
15.0μｍであること以外は上記実施例１と同様にして本
発明電池Ｃ１〜Ｃ４を作製した。The thickness of the conductive adhesive layer containing silver powder as the conductive material is 2.0 μm, 3.0 μm, 10.0 μm,
Except for 15.0 μm, batteries C1 to C4 of the present invention were produced in the same manner as in Example 1 above.
【００４０】このようにして作製した電池を、上記実験
１と同様にして、電池特性を調べた。実験条件は、上記
実験１と同一である。この結果を、表３に示す。この表
３には、上記実験１で使用した電池Ａ１の結果も併せて
示してある。The battery characteristics thus obtained were examined in the same manner as in Experiment 1 described above. The experimental conditions are the same as in Experiment 1 described above. Table 3 shows the results. Table 3 also shows the results of the battery A1 used in Experiment 1 above.
【００４１】[0041]
【表３】 [Table 3]
【００４２】この表３より、導電性接着層の厚みが2.0
μｍ以下では容量維持率が、導電性接着層を配設しない
比較電池Ｘと同じであること、また厚みが15.0μｍ以上
では初期放電容量の低下が観察される。従って、導電性
接着層の厚みは3.0μｍ〜10.0μｍの範囲が望ましいこ
とがわかった。According to Table 3, the thickness of the conductive adhesive layer was 2.0
At μm or less, the capacity retention is the same as that of Comparative Battery X without the conductive adhesive layer, and at 15.0 μm or more, a decrease in the initial discharge capacity is observed. Therefore, it was found that the thickness of the conductive adhesive layer was desirably in the range of 3.0 μm to 10.0 μm.
【００４３】尚、この導電性接着層の厚みの傾向につい
ては、銀以外の、ニッケル及び炭素においても、同様に
観察される。The tendency of the thickness of the conductive adhesive layer is similarly observed in nickel and carbon other than silver.
【００４４】上述の実施例では、渦巻き電極体を有した
円筒形電池に適用する場合について説明したが、本発明
電池はその形状に特に制限はなく、扁平形、角形など、
他の種々の形状の非水系電解質電池に適用しうるもので
ある。In the above-described embodiment, the case where the present invention is applied to a cylindrical battery having a spiral electrode body has been described. However, the shape of the battery of the present invention is not particularly limited.
The present invention can be applied to other various shapes of non-aqueous electrolyte batteries.
【００４５】[0045]
【発明の効果】本発明のリチウム二次電池用正極は、正
極集電体上にあらかじめ導電性接着層を配設すること
で、集電体と正極合材層の導電性を損なうことなく、こ
の集電体と正極合材層との密着性、接着性が向上する。
かかる正極を用いたリチウム二次電池において、充放電
サイクル経過に伴う集電体からの電極活物質の脱落を防
止し、長サイクル寿命化が可能となるものであり、その
工業的価値は極めて大きい。The positive electrode for a lithium secondary battery of the present invention can be obtained by disposing a conductive adhesive layer on the positive electrode current collector in advance without impairing the conductivity between the current collector and the positive electrode mixture layer. The adhesion and adhesion between the current collector and the positive electrode mixture layer are improved.
In a lithium secondary battery using such a positive electrode, it is possible to prevent the electrode active material from falling off from the current collector due to the progress of the charge / discharge cycle and to prolong the cycle life, and its industrial value is extremely large. .
【図１】本発明に係るリチウム二次電池用正極の模式的
断面図である。FIG. 1 is a schematic sectional view of a positive electrode for a lithium secondary battery according to the present invention.
【図２】本発明に係るリチウム二次電池の断面図であ
る。FIG. 2 is a sectional view of a lithium secondary battery according to the present invention.
11 正極集電体 12 導電性接着層 13 正極合材層 １ 正極 ２ 負極 ３ セパレータ ４ 正極リード ５ 負極リード ６ 正極外部端子 ７ 負極缶 11 positive electrode current collector 12 conductive adhesive layer 13 positive electrode mixture layer 1 positive electrode 2 negative electrode 3 separator 4 positive electrode lead 5 negative electrode lead 6 positive external terminal 7 negative electrode can
フロントページの続き (72)発明者 米津 育郎 大阪府守口市京阪本通２丁目５番５号 三 洋電機株式会社内 (72)発明者 西尾 晃治 大阪府守口市京阪本通２丁目５番５号 三 洋電機株式会社内Continued on the front page (72) Inventor Ikuro Yonezu 2-5-1-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Nishio 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.
Claims (8)
材料と結着材とからなる正極合材層を、集電体上に配置
したリチウム二次電池用正極において、前記正極合材層
と前記集電体との間に、導電性接着層を配置したことを
特徴とするリチウム二次電池用正極。1. A positive electrode for a lithium secondary battery in which a positive electrode mixture layer composed of a positive electrode material capable of occluding and releasing lithium ions and a binder is disposed on a current collector. A positive electrode for a lithium secondary battery, wherein a conductive adhesive layer is disposed between the positive electrode and a current collector.
び炭素よりなる群から選択された少なくとも一つの導電
材料が含有されていることを特徴とする請求項１記載の
リチウム二次電池用正極。2. The lithium secondary battery according to claim 1, wherein the conductive adhesive layer contains at least one conductive material selected from the group consisting of silver, nickel and carbon. Positive electrode.
着層の重量に対して、2.0重量％〜20.0重量％であるこ
とを特徴とする請求項２記載のリチウム二次電池用正
極。3. The positive electrode for a lithium secondary battery according to claim 2, wherein the content of the conductive material is 2.0% by weight to 20.0% by weight based on the weight of the conductive adhesive layer.
に配置することを特徴とする請求項１記載のリチウム二
次電池用正極。4. The positive electrode for a lithium secondary battery according to claim 1, wherein said conductive adhesive layer is disposed on both sides of said current collector.
0.0μｍの範囲であることを特徴とする請求項１記載の
リチウム二次電池用正極。5. The conductive adhesive layer has a thickness of 3.0 μm to 1 μm.
The positive electrode for a lithium secondary battery according to claim 1, wherein the thickness is in a range of 0.0 µm.
正極材料は、金属酸化物であることを特徴とする請求項
１記載のリチウム二次電池用正極。6. The positive electrode for a lithium secondary battery according to claim 1, wherein the positive electrode material capable of inserting and extracting lithium ions is a metal oxide.
CO1-xNixO2、LiMn2O 4及びこれらの複合化物からなる群
から選択された少なくとも1種の材料であることを特徴
とする請求項６記載のリチウム二次電池用正極。7. The method according to claim 1, wherein the metal oxide is LiCOO.Two, LiNiOTwo, Li
CO1-xNixOTwo, LiMnTwoO FourAnd a group consisting of these composites
Characterized in that it is at least one material selected from
The positive electrode for a lithium secondary battery according to claim 6, wherein
二次電池用正極を備えたことを特徴とするリチウム二次
電池。8. A lithium secondary battery comprising the positive electrode for a lithium secondary battery according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10118502A JPH11312516A (en) | 1998-04-28 | 1998-04-28 | Positive electrode for lithium secondary battery and lithium secondary battery using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10118502A JPH11312516A (en) | 1998-04-28 | 1998-04-28 | Positive electrode for lithium secondary battery and lithium secondary battery using the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11312516A true JPH11312516A (en) | 1999-11-09 |
Family
ID=14738264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10118502A Pending JPH11312516A (en) | 1998-04-28 | 1998-04-28 | Positive electrode for lithium secondary battery and lithium secondary battery using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11312516A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100416115B1 (en) * | 2000-03-31 | 2004-01-31 | 아토피나 | Structure comprising a fluoro primer and electrode based on this structure |
| US20130011732A1 (en) * | 2011-07-06 | 2013-01-10 | Jun-Sik Kim | Secondary battery |
| US8530087B2 (en) | 2010-01-29 | 2013-09-10 | Hitachi, Ltd. | Secondary lithium battery |
| RU2497239C2 (en) * | 2008-12-19 | 2013-10-27 | Ниссан Мотор Ко., Лтд. | Electrode and its manufacturing method |
| WO2014024926A1 (en) | 2012-08-09 | 2014-02-13 | トヨタ自動車株式会社 | All-solid-state battery and method for manufacturing same |
| JP2014116164A (en) * | 2012-12-07 | 2014-06-26 | Samsung R&D Institute Japan Co Ltd | Solid-state battery |
| US9905838B2 (en) | 2011-08-30 | 2018-02-27 | Gs Yuasa International Ltd. | Electrode and method of manufacturing the same |
| KR20200011861A (en) * | 2017-05-30 | 2020-02-04 | 아모르 | Cathode of accumulators, associated accumulators and batteries |
-
1998
- 1998-04-28 JP JP10118502A patent/JPH11312516A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100416115B1 (en) * | 2000-03-31 | 2004-01-31 | 아토피나 | Structure comprising a fluoro primer and electrode based on this structure |
| RU2497239C2 (en) * | 2008-12-19 | 2013-10-27 | Ниссан Мотор Ко., Лтд. | Electrode and its manufacturing method |
| US8785041B2 (en) | 2008-12-19 | 2014-07-22 | Nissan Motor Co., Ltd. | Electrode and production method thereof |
| US8530087B2 (en) | 2010-01-29 | 2013-09-10 | Hitachi, Ltd. | Secondary lithium battery |
| US20130011732A1 (en) * | 2011-07-06 | 2013-01-10 | Jun-Sik Kim | Secondary battery |
| US10367205B2 (en) * | 2011-07-06 | 2019-07-30 | Samsung Sdi Co., Ltd. | Secondary battery |
| US9905838B2 (en) | 2011-08-30 | 2018-02-27 | Gs Yuasa International Ltd. | Electrode and method of manufacturing the same |
| WO2014024926A1 (en) | 2012-08-09 | 2014-02-13 | トヨタ自動車株式会社 | All-solid-state battery and method for manufacturing same |
| JP2014035888A (en) * | 2012-08-09 | 2014-02-24 | Toyota Motor Corp | Solid state battery and manufacturing method thereof |
| JP2014116164A (en) * | 2012-12-07 | 2014-06-26 | Samsung R&D Institute Japan Co Ltd | Solid-state battery |
| KR20200011861A (en) * | 2017-05-30 | 2020-02-04 | 아모르 | Cathode of accumulators, associated accumulators and batteries |
| US11217794B2 (en) | 2017-05-30 | 2022-01-04 | Armor | Cathode of accumulator, associated accumulator and battery |
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