JP2707664B2 - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JP2707664B2 JP2707664B2 JP63321034A JP32103488A JP2707664B2 JP 2707664 B2 JP2707664 B2 JP 2707664B2 JP 63321034 A JP63321034 A JP 63321034A JP 32103488 A JP32103488 A JP 32103488A JP 2707664 B2 JP2707664 B2 JP 2707664B2
- Authority
- JP
- Japan
- Prior art keywords
- lithium
- negative electrode
- positive electrode
- battery
- thin film
- 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 - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/381—Alkaline or alkaline earth metals elements
- H01M4/382—Lithium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/043—Processes of manufacture in general involving compressing or compaction
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Description
【発明の詳細な説明】 産業上の利用分野 本発明は電子機器のメモリー保持電源もしくはポータ
ブル電子機器の駆動用電源としての有機電解質リチウム
二次電池の充放電特性の改良に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in charge / discharge characteristics of an organic electrolyte lithium secondary battery as a power supply for holding a memory of an electronic device or a power supply for driving a portable electronic device.
従来の技術 エネルギー密度が大きく、保存性，自己放電特性，耐
漏液性にすぐれるなどの特長を持つリチウム一次電池は
すでにフッ化黒鉛・リチウム電池，二酸化マンガン・リ
チウム電池，塩化チオニル・リチウム電池などが実用化
されている。2. Description of the Related Art Lithium primary batteries with high energy density, excellent preservability, self-discharge characteristics, and excellent resistance to liquid leakage have already been used, such as graphite / lithium fluoride batteries, manganese dioxide / lithium batteries, and thionyl chloride / lithium batteries. Has been put to practical use.
一方、最近の電子機器の小形化，ポータブル化に伴
い、それに使用する電源としての電池も小形化，軽量化
が要求され、そのため電池の電気容量が十分に確保され
ないという問題が生じてきた。これに対し前記のリチウ
ム電池の特長を維持しつつ、且つ充電しさえすれば何回
でもくり返し使用できるという、リチウム二次電池への
要望が高まってきている。On the other hand, with the recent miniaturization and portableness of electronic devices, batteries used as power sources for them have also been required to be smaller and lighter, which has caused a problem that the electric capacity of the batteries cannot be sufficiently secured. On the other hand, there is an increasing demand for a lithium secondary battery that can be used repeatedly as long as it is charged while maintaining the characteristics of the lithium battery.
リチウム二次電池としては、例えば特開昭61−5262号
公報にみられる如く、正極活物質として二硫化モリブデ
ンを用いるものが一部実用化されているが、より高エネ
ルギー密度、良好な充放電サイクル特性を目指し、現在
なお盛んに研究がおこなわれている。As lithium secondary batteries, for example, those using molybdenum disulfide as a positive electrode active material have been partially put to practical use, as seen in Japanese Patent Application Laid-Open No. Sho 61-5262, but have higher energy density and better charge / discharge. At present, research is being actively conducted to achieve cycle characteristics.
リチウム二次電池の正極活物質としては、この二硫化
モリブデンを始めとして、二硫化チタン、二酸化マンガ
ン、バナジウム酸化物、クロム酸化物などの無機化合物
あるいはポリアニリン，ポリピロール，ポリアセチレン
などの有機ポリマーがすぐれた可逆性を有するものとし
て知られている。それにもかかわらず、現在リチウム二
次電池が本格的に実用化されない最も大きな理由とし
て、負極活物質であるリチウムの貧困な充放電可逆性が
挙げられる。Molybdenum disulfide, inorganic compounds such as titanium disulfide, manganese dioxide, vanadium oxide, chromium oxide, and organic polymers such as polyaniline, polypyrrole, and polyacetylene are excellent as the positive electrode active material for lithium secondary batteries. It is known as having reversibility. Nevertheless, one of the biggest reasons that lithium secondary batteries are not put into practical use at present is the poor charge / discharge reversibility of lithium as a negative electrode active material.
リチウム極では充電時にリチウムが負極からイオンと
して電解質中に溶解し、充電時には逆に電解質中のリチ
ウムイオンが再び負極上に析出するという形態をとる。
問題は充電時にリチウムイオンが負極上にリチウムとし
て析出する際、樹枝状の生成物（デンドライト）が生成
し、充放電をくり返すにつれて負極からはがれて電池の
電気容量が低下する、あるいは特定部分にデンドライト
が過剰に成長し、セパレータを突き破って正極と短絡
し、電池の充放電サイクル寿命が尽きるなどの現象が生
じるということである。The lithium electrode takes a form in which lithium is dissolved from the negative electrode as ions in the electrolyte during charging, and lithium ions in the electrolyte are deposited again on the negative electrode during charging.
The problem is that when lithium ions are deposited as lithium on the negative electrode during charging, dendritic products (dendrites) are formed, which are detached from the negative electrode as charging and discharging are repeated, and the electric capacity of the battery is reduced. This means that the dendrite grows excessively, breaks through the separator, short-circuits with the positive electrode, and causes a phenomenon such as the end of the charge / discharge cycle life of the battery.
デンドライトの生成する原因としては、まずリチウム
極の表面に電解質中のリチウムイオンが偏在して析出
し、更にその上のより析出し易い部分に優先的に次々と
リチウムが析出するため、その部分が異常に成長する結
果おこるものであると考えられている。従ってこの現象
を抑制するためには、セパレータを介して相対する正極
板、負極板の各部分での反応が均一、言いかえれば反応
の電流分布が一定であればよい。即ち実際の電池の充放
電時には、微視的に見れば正極板・負極板の各部分でわ
ずかな電位差が認められるものの、一般的には等電位の
方向に動くはずであるから、正極板・負極板の表面の各
部分のそれぞれの集電端子部分からの電気抵抗が一定と
なるようにすれば、それぞれの部分での反応の電流分布
は一定となり、デンドライトの生成は妨げることにな
る。従って、通常、リチウム二次電池の製作に当って
は、このデンドライトの抑制および正極・負極の活物質
の均一な反応を目的として、正極板、負極板へ適切な材
質の金属ネットあるいはエキスパンデッドメタルを圧入
あるいは圧着して用いている。As a cause of dendrite generation, first, lithium ions in the electrolyte are unevenly deposited on the surface of the lithium electrode, and further, lithium is preferentially deposited one after another on a portion on which lithium ions are more easily deposited. It is believed to be the result of abnormal growth. Therefore, in order to suppress this phenomenon, it suffices that the reaction in each part of the positive electrode plate and the negative electrode plate facing each other via the separator is uniform, in other words, the current distribution of the reaction is constant. In other words, when the battery is actually charged and discharged, although a slight potential difference is observed in each part of the positive electrode plate and the negative electrode plate when viewed microscopically, the positive electrode plate and the negative electrode plate generally move in the same potential direction. If the electric resistance from each current collecting terminal portion of each portion on the surface of the negative electrode plate is made constant, the current distribution of the reaction in each portion becomes constant, and the generation of dendrite will be hindered. Therefore, in the manufacture of a lithium secondary battery, usually, for the purpose of suppressing the dendrite and uniform reaction of the active material of the positive electrode and the negative electrode, a metal net or expanded material of an appropriate material is applied to the positive electrode plate and the negative electrode plate. Metal is press-fitted or crimped.
発明が解決しようとする課題 上記した如く、正極・負極に金属ネットあるいはエキ
スパンデッドメタルを集電体として圧入あるいは圧着す
ることにより、それぞれの集電端子部分からそれぞれの
反応表面部分までの抵抗がほぼ一定に保たれるので、電
池の充電時に負極表面へのデンドライトの生成を抑制す
ることとなり、充放電サイクル寿命特性が大きく向上す
るものの、ここに一つの問題が発生する。即ち比較的低
電流、例えば１平方センチメートル当り0.1mA程度以下
の電流で電池を充電する場合、この方法はデンドライト
の生成を抑制するという効果を生じるものの、それ以上
の電流で電池を充電すると徐々にデンドライトの生成が
観察され、比較的短期間で充放電サイクル寿命がつきる
という現象が見られる。これは上記の場合よりも更に微
視的に正極・負極を眺めてみると、金属ネットあるいは
エキスパンデッドメタルの金属部分の存在する電極表面
部分の集電端子部分からの抵抗と、金属部分の存在しな
い電極表面部分の抵抗との微妙な違いが、比較的大きな
電流で電池を充電する場合にリチウム負極の表面の反応
のバラツキとなって現われてくるからと考えられる。従
ってリチウム負極へのデンドライトの生成を抑止し、良
好な充放電サイクル寿命を得るためには、充電電流とし
て、リチウム負極の１平方センチメートル当り0.1mA以
下となるような低電流でおこなえればよいが、通常充電
の目安となる10時間率程度の充電をおこなおうとすれ
ば、電極面積として膨大な面積が必要となり、電池の製
作上の問題、あるいは電池への充填電気量（電池の電気
容量）が減少するという問題が発生し、これらの問題を
解決しなければならないという課題が生じることにな
る。PROBLEM TO BE SOLVED BY THE INVENTION As described above, by press-fitting or crimping a metal net or expanded metal to the positive electrode / negative electrode as a current collector, the resistance from each current collector terminal portion to each reaction surface portion is reduced. Since it is kept substantially constant, the generation of dendrites on the surface of the negative electrode during charging of the battery is suppressed, and although the charge-discharge cycle life characteristics are greatly improved, one problem occurs here. That is, when a battery is charged with a relatively low current, for example, a current of about 0.1 mA per square centimeter or less, this method has an effect of suppressing the generation of dendrite. Is observed, and a phenomenon is seen in which the charge / discharge cycle life is relatively short. This is because the resistance from the current collecting terminal part on the electrode surface where the metal part of the metal net or expanded metal exists, and the resistance of the metal part It is considered that a slight difference from the resistance of the non-existent electrode surface portion appears as a variation in the reaction of the surface of the lithium negative electrode when the battery is charged with a relatively large current. Therefore, in order to suppress the generation of dendrites on the lithium anode and obtain a good charge / discharge cycle life, the charge current may be set at a low current of 0.1 mA or less per square centimeter of the lithium anode, Attempting to charge at a rate of about 10 hours, which is a standard for normal charging, requires an enormous area as the electrode area, which leads to problems in battery fabrication or the amount of electricity charged into the battery (battery capacity). The problem of reduction occurs, and the problem that these problems must be solved arises.
課題を解決するための手段 本発明はこのような課題を解決するものであり、金属
薄膜に正極合剤を塗着もしくは圧着してなる正極板と、
金属薄膜の両面にリチウムを圧着してなる負極板とをセ
パレータを介して渦巻状に巻回した極板群と、有機電解
質とを有するリチウム二次電池を提供するものである。Means for solving the problem The present invention is to solve such problems, a positive electrode plate obtained by applying or pressing a positive electrode mixture on a metal thin film,
An object of the present invention is to provide a lithium secondary battery having an electrode group in which a negative electrode plate formed by pressurizing lithium on both surfaces of a metal thin film is spirally wound via a separator, and an organic electrolyte.
作用 上述した如く、リチウム二次電池では充電の際デンド
ライトの発生を抑止するためできるだけ小さな電流で充
電する必要があり、充電時間を短くするためには電極面
積を大きくすることが不可欠である。さらにその結果と
して、電池製作時の工程が複雑になる、あるいは電池の
充放電反応に直接関与しないセパレータの体積が増加し
電池の電気容量が減少するという問題が発生する。Operation As described above, a lithium secondary battery needs to be charged with a current as small as possible in order to suppress the generation of dendrite during charging, and it is essential to increase the electrode area in order to shorten the charging time. Further, as a result, there arises a problem that the process of manufacturing the battery becomes complicated, or the volume of the separator not directly involved in the charge / discharge reaction of the battery increases, and the electric capacity of the battery decreases.
本発明はこれらのことを勘案して、正極および負極の
集合体として金属薄膜を用いることを提案するものであ
る。即ちこのようにすれば、正極あるいは負極の表面の
どの部分もそれぞれの集電体である金属薄膜から等距離
にあり、電池の充電の際の集電体からの距離の微妙な違
いから生じる電気抵抗差ひいてはそれぞれの集電端子部
分からの電気抵抗差のための反応の不均一によるデンド
ライトの発生を防ぎ、充放電サイクル寿命特性のすぐれ
たリチウム二次電池を提供し得るものである。但しこの
場合、正極集電体として、空孔部分を有する金属ネット
あるいはエキスパンデッドメタルを用いず、金属薄膜を
用いるため、正極合剤を空孔部分に圧入するという方法
ではなく、必然的に正極合剤を金属薄膜の面に塗着もし
くは圧着するという方法をとることになる。一方、負極
は金属薄膜の両面にリチウムを圧着することにより形成
し得る。また同時に注意しなければならないことは、当
然のことではあるが、正極・負極に用いる金属薄膜はそ
れぞれ正極活物質あるいはリチウムと反応するものであ
ってはならない。そのような金属薄膜としては種々考え
られるが、加工性，経済性などを考慮して、正極用金属
薄膜としては、アルミニウム，チタン，ステンレス鋼
が、負極用金属薄膜としてはニッケル，銅，ステンレス
鋼が望ましい。以下実施例で説明する。The present invention, in view of these facts, proposes to use a metal thin film as an assembly of a positive electrode and a negative electrode. That is, in this way, any part of the surface of the positive electrode or the negative electrode is equidistant from the metal thin film that is the current collector, and the electricity generated due to a subtle difference in the distance from the current collector when charging the battery. An object of the present invention is to provide a lithium secondary battery having excellent charge / discharge cycle life characteristics by preventing the occurrence of dendrites due to the non-uniformity of the reaction due to the difference in resistance and, consequently, the difference in electric resistance from each current collecting terminal portion. However, in this case, as a positive electrode current collector, a metal thin film having a hole portion or an expanded metal is not used, and a metal thin film is used. The positive electrode mixture is applied or pressed onto the surface of the metal thin film. On the other hand, the negative electrode can be formed by pressing lithium on both surfaces of the metal thin film. At the same time, it should be noted that the metal thin films used for the positive electrode and the negative electrode must not react with the positive electrode active material or lithium, respectively. Various types of such metal thin films are conceivable. Considering workability and economy, aluminum, titanium, and stainless steel are used as positive metal thin films, and nickel, copper, and stainless steel are used as negative metal thin films. Is desirable. Hereinafter, an embodiment will be described.
実施例 実施例１ 第１図は本発明の実施例における電池の断面図であ
る。第１図において、１は正極板であり、正極活物質の
二酸化マンガンと導電材のカーボン粉末と接着剤の四フ
ッ化エチレンの水洗ディスパージョンと増粘剤のカルボ
キシメチルセルロース（CMC）を重量比で100:7:7:1の割
合でペースト状に混練したものを厚さ30μｍのアルミニ
ウム箔２の両面に塗着した後乾燥し、圧延し、所定の大
きさに切断してある。但しこれらの材料のうち四フッ化
エチレンの水性ディスパージョンの混合した重量割合
は、ディスパージョン中の固形分として計算している。
この時の正極活物質の理論充填電気量は二酸化マンガン
の１価の反応として1400mAhである。３はセパレータで
多孔性のポリプロピレン製フィルムを用いている。４は
リチウム負極で５の厚さ20μｍのニッケル箔の両面にリ
チウムを圧着したものであり、その理論充填電気量は28
00mAhである。この正極と負極をセパレータを介して重
ね合せ、渦巻状に巻回してケース９内に挿入する。挿入
後６のチタン製リードを７のステンレス製封口板にスポ
ット溶接する。８は鉄にニッケルメッキした正極キャッ
プ兼正極端子であらかじめ封口板７にスポット溶接され
ている。また負極集電体５の端部は負極端子を兼ねたケ
ース９にスポット溶接する。10はポリプロピレン製の絶
縁板であり、11は同じくポリプロピレン製の絶縁ガスケ
ットである。12は電池に異常がおきて、電池内圧が上昇
した場合に内部のガスが外部へ放出されるよう取り付け
てある安全弁である。以上の操作の後、六フッ化リン酸
リチウム（LiPF6）をプロピレンカーボネート中に１モ
ル/lの割合で溶かした電解質を注入し、電池を封口す
る。完成電池のサイズは単３形（14.5φ×50mm）であ
る。この本発明電池を電池Ａとする。EXAMPLES Example 1 FIG. 1 is a sectional view of a battery according to an example of the present invention. In FIG. 1, reference numeral 1 denotes a positive electrode plate, which is composed of manganese dioxide as a positive electrode active material, carbon powder as a conductive material, a water washing dispersion of ethylene tetrafluoride as an adhesive, and carboxymethyl cellulose (CMC) as a thickener in a weight ratio. A paste kneaded at a ratio of 100: 7: 7: 1 is applied to both surfaces of an aluminum foil 2 having a thickness of 30 μm, dried, rolled, and cut into a predetermined size. However, of these materials, the weight ratio of the mixed aqueous dispersion of ethylene tetrafluoride is calculated as the solid content in the dispersion.
At this time, the theoretical charge amount of the positive electrode active material is 1400 mAh as a monovalent reaction of manganese dioxide. Reference numeral 3 denotes a separator using a porous polypropylene film. Reference numeral 4 denotes a lithium negative electrode obtained by compressing lithium on both sides of a nickel foil 5 having a thickness of 20 μm, and the theoretical charge amount of the lithium foil is 28.
00 mAh. The positive electrode and the negative electrode are overlapped via a separator, spirally wound, and inserted into the case 9. After the insertion, the titanium lead 6 is spot-welded to the stainless steel sealing plate 7. Reference numeral 8 denotes a positive electrode cap / positive terminal plated with nickel on iron, which is spot-welded to the sealing plate 7 in advance. The end of the negative electrode current collector 5 is spot-welded to the case 9 also serving as a negative electrode terminal. Reference numeral 10 denotes a polypropylene insulating plate, and reference numeral 11 denotes a polypropylene insulating gasket. Reference numeral 12 denotes a safety valve attached so that the internal gas is released to the outside when the battery internal pressure rises due to an abnormality in the battery. After the above operation, an electrolyte in which lithium hexafluorophosphate (LiPF 6 ) is dissolved in propylene carbonate at a rate of 1 mol / l is injected, and the battery is sealed. The size of the completed battery is AA (14.5φ × 50mm). This battery of the present invention is referred to as Battery A.
次に電池Ａと全く同じ構成で正極集電体２だけをチタ
ンネットに変え、前記正極合剤ペーストを圧入し、正極
とした電池を電池Ｂとする。この場合の正極および負極
の理論充填電気量は電池Ａと同じである。Next, with the same configuration as the battery A, only the positive electrode current collector 2 was changed to a titanium net, and the positive electrode mixture paste was press-fitted into the battery. In this case, the theoretical charge amount of the positive electrode and the negative electrode is the same as that of the battery A.
また電池A,Bと全く同じ構成で、負極集電体５のみを
ニッケルネットに変えた電池をそれぞれ電池C,Dとす
る。この場合の正極および負極の理論充填電気量は電池
A,Bと同じである。Batteries having exactly the same configuration as the batteries A and B, except that only the negative electrode current collector 5 is changed to nickel net, are referred to as batteries C and D, respectively. In this case, the theoretical charge of the positive and negative electrodes is
Same as A, B.
さらに電池A,Bと全く同じ構成で、負極リチウム全体
には集電体を用いず、負極の端部のみにニッケルリボン
を圧着し負極集電体とした電池をそれぞれ電池E,Fとす
る。当然のことながら電池E,Fは負極全体にわたる集電
体を有していないため、その分リチウムの充電量が増加
し、3200mAhとなっている。Furthermore, batteries having exactly the same configuration as the batteries A and B, and using no current collector for the entire negative electrode lithium, and forming a negative electrode current collector by pressing a nickel ribbon only on the end of the negative electrode, are referred to as batteries E and F, respectively. As a matter of course, since the batteries E and F do not have a current collector over the entire negative electrode, the charge amount of lithium increases by that much to 3200 mAh.
これら電池Ａ〜Ｆを20℃で70mAの電流で3.8Vと2.0Vの
電圧範囲内で充放電した時の充放電サイクル数とそれぞ
れのサイクルでの放電容量をプロットしたものを第２図
に示す。この時電極の単位面積当りの充放電電流密度は
0.33mA/cm2となる。FIG. 2 shows the number of charge / discharge cycles and the discharge capacity in each cycle when these batteries A to F were charged and discharged at a current of 70 mA at 20 ° C. within a voltage range of 3.8 V and 2.0 V. . At this time, the charge / discharge current density per unit area of the electrode is
0.33 mA / cm 2 .
図から明らかなように、本発明電池Ａは充放電を200
サイクルくり返した時点でも良好な特性を有しており、
負極へのデンドライトの発生は認められなかった。初期
にくらべて若干放電容量が低下しているのは、充放電サ
イクルに伴う正極の特性低下である。一方正極の集電体
のみ電池Ａと異る電池Ｂも比較的良好な特性を示すが、
ほゞ180サイクル時点でデンドライトが発生し、電池の
寿命が尽きた。As is clear from the figure, the battery A of the present invention has a charge / discharge of 200
It has good characteristics even after repeated cycles,
No generation of dendrites on the negative electrode was observed. The fact that the discharge capacity is slightly reduced as compared with the initial stage is a decrease in the characteristics of the positive electrode due to the charge / discharge cycle. On the other hand, battery B, which differs from battery A only in the positive electrode current collector, also shows relatively good characteristics,
At about 180 cycles, dendrite was generated, and the battery life was exhausted.
一方、負極の集電体としてニッケルネットを用いた電
池C,Dはそれぞれほゞ140サイクル、130サイクル時点で
デンドライトが発生し、電池の寿命が尽きた。On the other hand, in batteries C and D using nickel net as the current collector of the negative electrode, dendrites were generated at about 140 cycles and 130 cycles, respectively, and the life of the batteries was exhausted.
また、負極に集電体を用いていない電池はさらに寿命
が短く、電池E,Fはほゞ70数サイクルで寿命が尽きた。In addition, the battery in which the current collector was not used for the negative electrode had a shorter life, and the life of the batteries E and F was exhausted in about 70 cycles.
これらの結果から明らかなように、電池の充放電サイ
クル寿命特性に最も大きな影響を与えるものは負極集電
体の有無であり、しかも集電体が有る場合でも金属薄膜
と金属ネットでは充放電サイクル寿命特性に大きな差が
あることが判る。即ち、前記した如く、負極集電体とし
て金属薄膜を用い負極リチウムの表面の各部分の負極端
子部からの抵抗差を殆んどなくした電池A,Bは、負極集
電体として金属ネットを用い、負極リチウム表面の各部
分の負極端子部からの抵抗に微妙な差を有する電池C,D
とくらべ良好な特性を示す。更に負極集電体が同じであ
っても、電池ＡとB,CとＤ、あるいはＥとＦにみられる
ように、正極集電体として金属薄膜を用いた電池A,C,E
は、金属ネットを用いた電池B,D,Fよりも良好な特性を
示す。このことからも判るように、電池の充放電サイク
ル寿命特性に起因する負極のデンドライトの生成は正極
の集電体の計上によっても影響されることが判る。以上
のことから、本発明の如く、正極として金属薄膜に正極
合剤を塗着し、圧延したもの、負極として金属薄膜の両
面にリチウムを圧着したものを用いて電池を構成するこ
とにより、放電電気量が大で、デンドライトの発生がな
い、充放電サイクル寿命特性にすぐれたリチウム二次電
池が得られる。As is evident from these results, the one that has the greatest effect on the charge-discharge cycle life characteristics of the battery is the presence or absence of the negative electrode current collector. It can be seen that there is a large difference in the life characteristics. That is, as described above, the batteries A and B in which a metal thin film is used as the negative electrode current collector and the difference in resistance between each part of the surface of the negative electrode lithium and the negative electrode terminal is almost zero, the metal net is used as the negative electrode current collector. Batteries C and D that have a slight difference in resistance from the negative electrode terminal of each part of the negative electrode lithium surface
It shows better characteristics than the ones. Further, even if the negative electrode current collectors are the same, as shown in batteries A and B, C and D, or E and F, batteries A, C and E using a metal thin film as the positive electrode current collector
Shows better characteristics than batteries B, D, and F using metal nets. As can be seen from this, it is understood that the generation of dendrite of the negative electrode due to the charge / discharge cycle life characteristics of the battery is also affected by the count of the current collector of the positive electrode. From the above, as in the present invention, a positive electrode mixture is applied to a metal thin film as a positive electrode and rolled, and as a negative electrode, a battery is formed using a metal thin film in which lithium is pressure-bonded to both surfaces of a metal thin film, thereby discharging. A lithium secondary battery with a large amount of electricity, no dendrite generation, and excellent charge-discharge cycle life characteristics can be obtained.
実施例２ 正極活物質として五酸化バナジウムを、正極集電体と
してステンレス鋼の薄膜とネットを、負極集電体として
銅の薄膜とネットを、さらに電解質としてプロピレンカ
ーボネートと1,2ジメトキシエタンを体積比で1:1に混合
したものに過塩素酸リチウム（LiCl4）を１モル/lの割
合で溶かしたものを用いる以外は全く実施例１と同様に
構成した電池をＡ′〜Ｆ′とする。但し正極活物質とし
て五酸化バナジウムを用いたことから、電池Ａ′〜Ｆ′
の正極の理論充填電気量は650mAhである。一方負極の理
論充填電気量は実施例１と同様で電池Ａ′〜Ｄ′は2800
mAhであり、電池Ｅ′,F′は3200mAhである。Example 2 Vanadium pentoxide was used as a positive electrode active material, a stainless steel thin film and a net were used as a positive electrode current collector, a copper thin film and a net were used as a negative electrode current collector, and propylene carbonate and 1,2 dimethoxyethane were used as an electrolyte. Batteries constructed in exactly the same manner as in Example 1 except that lithium perchlorate (LiCl 4 ) was dissolved at a ratio of 1 mol / l in a mixture mixed at a ratio of 1: 1 were designated as A ′ to F ′. I do. However, since vanadium pentoxide was used as the positive electrode active material, batteries A 'to F'
The theoretical charge of the positive electrode is 650 mAh. On the other hand, the theoretical charge amount of the negative electrode was the same as in Example 1, and the batteries A 'to D'
mAh, and the batteries E 'and F' are 3200 mAh.
これら電池Ａ′〜Ｆ′を20℃で60mAの定電流で4.0Vと
2.5Vの電圧範囲で充放電した時の充放電サイクル数とそ
れぞれのサイクルでの放電容量をプロットしたものを第
３図に示す。この時の電極の単位面積当りの充放電電流
密度は 0.28mA/cm2となる。These batteries A 'to F' were converted to 4.0 V at a constant current of 60 mA at 20 ° C.
FIG. 3 shows a plot of the number of charge / discharge cycles when charging / discharging in the voltage range of 2.5 V and the discharge capacity in each cycle. At this time, the charge / discharge current density per unit area of the electrode is 0.28 mA / cm 2 .
第３図からも明らかなように、本発明電池Ａ′はすぐ
れた充放電サイクル寿命特性を示すことが判る。このこ
とは、正極活物質の種類，集電体の材質，電解質の種類
にかかわりなく、正極および負極の集電体として金属薄
膜を用い、正極・負極の表面の各部分のそれぞれの集電
端子部分からの電気抵抗差をなくすことにより、電池の
充電時にデンドライトの発生のない、充放電サイクル寿
命特性のすぐれた電池を得ることができるものである。As is clear from FIG. 3, it is understood that the battery A 'of the present invention has excellent charge-discharge cycle life characteristics. This means that regardless of the type of the positive electrode active material, the material of the current collector, and the type of the electrolyte, a metal thin film is used as the current collector of the positive electrode and the negative electrode, and the current collecting terminals of each part of the surface of the positive electrode and the negative electrode are used. By eliminating the difference in electrical resistance from the parts, it is possible to obtain a battery having no charge / discharge cycle life characteristics without generation of dendrite during charging of the battery.
発明の効果 以上のことから明らかな如く、本発明によれば正極と
負極をセパレーターを介して渦巻き状に巻回してなる極
板群を有する有機電解質リチウム二次電池において、正
極板として金属薄膜に正極合剤を塗着もしくは圧着して
なるもの、負極板として金属薄膜の両面にリチウムを圧
着してなるものを用いることにより、それぞれの極板表
面の各部分のそれぞれの集電端子部分からの微妙な電気
抵抗差をなくすことにより、電池の充電時に負極のリチ
ウムの表面で均一に反応をおこなわせしめ、その結果、
デンドライトの発生を抑止して、充放電サイクル寿命特
性のすぐれたリチウム二次電池を提供てきるという効果
が得られるものである。なお実施例では正極活物質とし
て二酸化マンガンと五酸化バナジウム、正極集電体の金
属薄膜としてアルミニウムとステンレス鋼、負極集電体
の金属薄膜としてニッケルと銅、電解質としてプロピレ
ンカーボネートに六フッ化リン酸リチウムを溶解したも
のとプロピレンカーボネートと1,2ジメトキシエタンを
混合したものに過塩素酸リチウムを溶解したもののみを
示したが、すくなくとも本発明は、この発明の趣旨を変
えないすべての態様に適用し得るものであることは言う
までもない。Effects of the Invention As is clear from the above, according to the present invention, in an organic electrolyte lithium secondary battery having an electrode group formed by spirally winding a positive electrode and a negative electrode via a separator, a metal thin film is used as a positive electrode plate. By applying or compressing the positive electrode mixture, and using the negative electrode plate formed by pressing lithium on both sides of the metal thin film, each part of the surface of each electrode plate can be separated from each current collector terminal part. Eliminating the slight difference in electrical resistance allows the reaction to occur uniformly on the surface of the negative electrode lithium when charging the battery. As a result,
The effect of suppressing the generation of dendrite and providing a lithium secondary battery having excellent charge / discharge cycle life characteristics can be obtained. In this example, manganese dioxide and vanadium pentoxide were used as the positive electrode active material, aluminum and stainless steel as the metal thin film of the positive electrode current collector, nickel and copper as the metal thin film of the negative electrode current collector, propylene carbonate as the electrolyte and hexafluorophosphoric acid. Only those in which lithium is dissolved and those in which lithium perchlorate is dissolved in a mixture of propylene carbonate and 1,2 dimethoxyethane are shown, but at least the present invention is applicable to all aspects which do not change the gist of the present invention. It goes without saying that it can be done.
第１図は本発明の実施例で用いた円筒形電池の構成図、
第２図および第３図は本発明電池と在来電池の充放電サ
イクル寿命特性図である。 １……正極板、２……正極集電体、３……セパレータ、
４……負極板、５……負極集電体、６……正極リード、
７……封口板、８……正極端子（＋）、９……ケース
（−）、10……絶縁板、11……絶縁ガスケット、12……
安全弁。FIG. 1 is a configuration diagram of a cylindrical battery used in an embodiment of the present invention,
FIGS. 2 and 3 are charge / discharge cycle life characteristics of the battery of the present invention and a conventional battery. 1 ... Positive electrode plate, 2 ... Positive electrode current collector, 3 ... Separator,
4 ... negative electrode plate, 5 ... negative electrode current collector, 6 ... positive electrode lead,
7 ... sealing plate, 8 ... positive electrode terminal (+), 9 ... case (-), 10 ... insulating plate, 11 ... insulating gasket, 12 ...
safety valve.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 奥野 博美 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 昭62−243247（ＪＰ，Ａ) 特開 平１−105477（ＪＰ，Ａ) 特開 平１−272049（ＪＰ，Ａ) ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiromi Okuno 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-62-243247 (JP, A) JP-A-1- 105477 (JP, A) JP-A 1-272049 (JP, A)
Claims (4)
てなる正極板と、金属薄膜の両面にリチウムを圧着して
なる負極板とをセパレータを介して渦巻状に巻回した極
板群と、有機電解質とを有するリチウム二次電池。An electrode plate in which a positive electrode plate formed by applying or compressing a positive electrode mixture to a metal thin film and a negative electrode plate formed by pressing lithium on both surfaces of the metal thin film are spirally wound via a separator. A lithium secondary battery having a group and an organic electrolyte.
ン，ステンレス鋼からなる群から選ばれた１種である特
許請求の範囲第１項記載のリチウム二次電池。2. The lithium secondary battery according to claim 1, wherein the metal thin film of the positive electrode is one selected from the group consisting of aluminum, titanium, and stainless steel.
鋼，銅からなる群から選ばれた１種である特許請求の範
囲第１項に記載のリチウム二次電池。3. The lithium secondary battery according to claim 1, wherein the metal thin film of the negative electrode is one selected from the group consisting of nickel, stainless steel, and copper.
エチレンカーボネート，ジメチルカーボネート，γ−ブ
チロラクトンからなるエステル群より選ばれた１種もし
くは２種以上、あるいは1,2ジメトキシエタン，テトラ
ヒドロフラン,2メチルテトラヒドロフラン，ジオキソラ
ンからなるエーテル群より選ばれた１種もしくは２種以
上、あるいはこれらエステルとエーテルとの混合物から
なる溶媒に過塩素リチウム（LiClO4）、六フッ化リン酸
リチウム（LiPF6）、六フッ化砒酸リチウム（LiAs
F6）、ホウフッ化リチウム（LiBF4）、リチウムトリフ
ルオロメタンスルフォネート（LiCF3SO3）からなる群よ
り選ばれた１種もしくは２種以上の溶質を溶解させたも
のである特許請求の範囲第１項に記載のリチウム二次電
池。4. The method according to claim 1, wherein the organic electrolyte is propylene carbonate,
One or more selected from esters consisting of ethylene carbonate, dimethyl carbonate, and γ-butyrolactone; or one or two selected from ethers consisting of 1,2 dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, and dioxolane Lithium perchloride (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium hexafluoroarsenate (LiAs)
Claims wherein one or more solutes selected from the group consisting of F 6 ), lithium borofluoride (LiBF 4 ) and lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) are dissolved. 2. The lithium secondary battery according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63321034A JP2707664B2 (en) | 1988-12-19 | 1988-12-19 | Lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63321034A JP2707664B2 (en) | 1988-12-19 | 1988-12-19 | Lithium secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02165576A JPH02165576A (en) | 1990-06-26 |
| JP2707664B2 true JP2707664B2 (en) | 1998-02-04 |
Family
ID=18128061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63321034A Expired - Fee Related JP2707664B2 (en) | 1988-12-19 | 1988-12-19 | Lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2707664B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110592807A (en) * | 2019-09-18 | 2019-12-20 | 宁波大学 | Thin film material for inhibiting growth of lithium dendrite and preparation method thereof |
-
1988
- 1988-12-19 JP JP63321034A patent/JP2707664B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110592807A (en) * | 2019-09-18 | 2019-12-20 | 宁波大学 | Thin film material for inhibiting growth of lithium dendrite and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02165576A (en) | 1990-06-26 |
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