JPH10308237A - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JPH10308237A JPH10308237A JP10051698A JP5169898A JPH10308237A JP H10308237 A JPH10308237 A JP H10308237A JP 10051698 A JP10051698 A JP 10051698A JP 5169898 A JP5169898 A JP 5169898A JP H10308237 A JPH10308237 A JP H10308237A
- Authority
- JP
- Japan
- Prior art keywords
- lithium
- battery
- negative electrode
- organic electrolyte
- coin
- 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.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、リチウム二次電池
の特性改良、とくに充放電サイクル寿命特性に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in characteristics of a lithium secondary battery, and more particularly to a charge / discharge cycle life characteristic.
【０００２】[0002]
【従来の技術】負極活物質にリチウム金属を用いる電池
は、１９５０年代末の米国において軍事用および宇宙用
の新しい高性能電池の開発プロジェクトにおいて初めて
検討がなされた。リチウムは標準電極電位が低く電気化
学当量が大きいので、負極活物質に使用すると従来の電
池、例えば乾電池や鉛蓄電池と比べて高電圧、高エネル
ギー密度を有する電池が構成できる可能性が示された。
１９６０年代後半には日本においてもリチウム電池に関
する研究が開始され、世界で最初のリチウム電池は１９
７０年代初頭に開発された。リチウム金属の化学反応性
が極めて高く、安全な電池システムを見つけだすのが困
難であったが、電解質に非プロトン性の有機電解液を用
いることで安全性の高いリチウム電池が開発された。2. Description of the Related Art A battery using lithium metal as a negative electrode active material was first studied in the United States in the late 1950's in a project to develop a new high-performance battery for military and space use. Since lithium has a low standard electrode potential and a large electrochemical equivalent, it was shown that when used as a negative electrode active material, a battery having a higher voltage and a higher energy density than conventional batteries, such as a dry battery or a lead storage battery, could be constructed. .
Research on lithium batteries began in Japan in the late 1960s, and the world's first lithium battery was 19
Developed in the early 70's. Although the chemical reactivity of lithium metal was extremely high, it was difficult to find a safe battery system. However, a highly safe lithium battery was developed by using an aprotic organic electrolyte as an electrolyte.
【０００３】このリチウム電池は一次電池であり、充放
電可能な二次電池が開発されるためには多くの課題が存
在している。もっとも大きい課題としては、リチウムイ
オンがリチウム金属に還元され、基板となるリチウム金
属表面上に析出する際に針状や樹枝状の生成物、いわゆ
るリチウムデンドライトを生成し、正極との間にあるセ
パレータを貫通してショートをおこし、いろいろな不都
合を生じる。この現象は充放電電流密度により異なる
が、いずれも電池サイクル寿命が低下するという課題が
生じる。電池における充電反応は負極の還元反応に相当
し、繰り返し充放電反応を行うリチウム二次電池では重
大な課題となっている。[0003] This lithium battery is a primary battery, and there are many problems in developing a chargeable / dischargeable secondary battery. The biggest problem is that when lithium ions are reduced to lithium metal and precipitate on the surface of the lithium metal substrate, needle-like or dendritic products, so-called lithium dendrites, are formed, and the separator between the positive electrode and the cathode Causes short circuit, causing various inconveniences. This phenomenon varies depending on the charge / discharge current density, but in any case, the problem that the battery cycle life is reduced occurs. A charging reaction in a battery corresponds to a reduction reaction of a negative electrode, and is a serious problem in a lithium secondary battery that repeatedly performs a charging and discharging reaction.
【０００４】前記課題を解決し、安定なリチウム二次電
池を開発する手段として、負極活物質にリチウム金属の
代わりにリチウムイオンを吸蔵、放出する黒鉛や炭素材
料を負極活物質として用いる方法が検討され、１９９０
年には正極にコバルト酸リチウム、負極にリチウムイオ
ンを吸蔵、放出する炭素材料を用いたリチウム二次電池
（リチウムイオン二次電池）が発表され、１９９１年よ
り商品化されている。このリチウム二次電池はリチウム
金属を使用していないので、上記リチウムデンドライト
を生成せず安全であるとされ、長寿命かつ高エネルギー
密度である特長を生かした小型携帯機器の電源として、
現在その用途を急速に拡大している。As a means for solving the above-mentioned problems and developing a stable lithium secondary battery, a method of using graphite or a carbon material, which absorbs and releases lithium ions, as the negative electrode active material instead of lithium metal as the negative electrode active material has been studied. 1990
In 2000, a lithium secondary battery (lithium ion secondary battery) using lithium cobalt oxide for the positive electrode and a carbon material for inserting and extracting lithium ions in the negative electrode was announced, and has been commercialized since 1991. Since this lithium secondary battery does not use lithium metal, it is considered to be safe without generating the above-mentioned lithium dendrite, and as a power source for small portable devices utilizing the features of long life and high energy density,
Currently its use is expanding rapidly.
【０００５】しかし、負極に炭素材料を用いた場合、体
積あたりのエネルギー密度はリチウム金属に比べ低いた
め、電池のエネルギー密度もリチウム金属を負極に用い
た場合よりも相対的に低下する。すなわち、リチウム金
属の理論容量は３８６０ｍＡｈ／ｇであるが、リチウム
イオン二次電池に用いられている黒鉛負極の放電容量は
約３００ｍＡｈ／ｇと金属リチウムの１０分の１以下で
ある。電池のサイズによっても異なるが、実際に電池を
構成した場合、黒鉛負極を用いたリチウムイオン二次電
池は最大でも３７２Ｗｈ／ｌのエネルギー密度を有する
が、リチウム金属を用いた二次電池は約４００Ｗｈ／ｌ
のエネルギー密度が実現できる。よってエネルギー密度
を向上させるためには、リチウム金属を負極活物質とし
て使用することが望まれる。[0005] However, when a carbon material is used for the negative electrode, the energy density per volume is lower than that of lithium metal, so that the energy density of the battery is relatively lower than that when lithium metal is used for the negative electrode. That is, the theoretical capacity of lithium metal is 3860 mAh / g, but the discharge capacity of the graphite negative electrode used in the lithium ion secondary battery is about 300 mAh / g, which is 1/10 or less of lithium metal. Although it depends on the size of the battery, when a battery is actually constructed, a lithium ion secondary battery using a graphite negative electrode has an energy density of 372 Wh / l at the maximum, while a secondary battery using a lithium metal has an energy density of about 400 Wh / l. / L
Energy density can be realized. Therefore, in order to improve the energy density, it is desired to use lithium metal as the negative electrode active material.
【０００６】リチウムデンドライトが発生する機構につ
いては、様々な報告がなされているが、不明な部分が多
く確定はされていない。そのうちの１つとして「リチウ
ム析出・溶解過程の解析 大阪工業技術研究所 藤枝卓
也著 第２４回 電気化学講習会」では、とくにリチウ
ム金属を用いた電池では、リチウムの結晶子間に存在す
る粒界にデンドライトを生成しやすいと報告している。
すなわち粒界部分はエネルギー状態が高く、充電時のリ
チウム金属の析出反応が集中しやすいためデンドライト
状リチウムが生成される。よって粒界のエネルギーを低
下させるか、または粒界そのものを消滅させることで、
総体的にエネルギー状態が均一なリチウム金属負極が得
られ、充電時もリチウム負極上に均一かつ平滑にリチウ
ム金属が析出すると予想される。[0006] Various reports have been made on the mechanism by which lithium dendrite is generated, but many unclear portions have not been determined. One of them is "Analysis of Lithium Precipitation and Dissolution Process, Takuya Fujieda, Osaka Institute of Technology, The 24th Seminar on Electrochemistry", especially in batteries using lithium metal, the grain boundaries existing between lithium crystallites. Reports that dendrites are easily formed.
That is, since the energy state of the grain boundary portion is high and the precipitation reaction of lithium metal during charging is likely to be concentrated, dendritic lithium is generated. Therefore, by lowering the energy of the grain boundary or extinguishing the grain boundary itself,
It is expected that a lithium metal negative electrode having a uniform energy state as a whole is obtained, and that lithium metal is uniformly and smoothly deposited on the lithium negative electrode even during charging.
【０００７】リチウム金属の粒界を抑制する目的ではい
くつかの検討がなされており、負極でのリチウム金属に
アルミニウムやホウ素などを添加することにより合金を
用いたり、あるいは電池の電解液中に様々な有機または
無機物質を添加して均一にリチウム金属を析出させよう
とする試みがなされている。例えばアルミニウム塩を有
機電解液に添加する発明に関しては、特開昭６３−２５
７１８３号公報がある。Several studies have been made for the purpose of suppressing the grain boundary of lithium metal. For example, alloys are used by adding aluminum or boron to lithium metal at the negative electrode, or various kinds of electrolytes are used in the battery electrolyte. Attempts have been made to uniformly deposit lithium metal by adding an organic or inorganic substance. For example, with respect to the invention in which an aluminum salt is added to an organic electrolytic solution, JP-A-63-25
No. 7183.
【０００８】また、ＣＯ2ガスを有機電解液に添加する
方法は特開平７−１７６３２３号公報があり、これは充
電時にリチウムが均一に生成しないＬｉＯＨを抑制する
ためである。またＣＯ2ガス雰囲気下で処理した金属リ
チウムを負極として電池に使用する方法は、特開平６−
１２４７００号公報がある。いずれも金属リチウム表面
にＬｉ2ＣＯ3皮膜を形成させることを目的としている。
このＬｉ2ＣＯ3皮膜は電気伝導性が良好であり、また表
面のエネルギー状態が均一であるので、充電時のリチウ
ム金属デンドライトの発生が抑制される。[0008] A method of adding CO 2 gas to an organic electrolyte is disclosed in Japanese Patent Application Laid-Open No. 7-176323, in order to suppress LiOH in which lithium is not uniformly generated during charging. Further, a method of using metallic lithium treated in a CO 2 gas atmosphere as a negative electrode in a battery is disclosed in
There is 124700 publication. All aim at forming a Li 2 CO 3 film on the surface of metallic lithium.
Since this Li 2 CO 3 film has good electric conductivity and a uniform energy state on the surface, generation of lithium metal dendrite during charging is suppressed.
【０００９】[0009]
【発明が解決しようとしている課題】前記の既に公に知
られている手段により、リチウム金属負極を用いた電池
の充放電サイクル特性は確かに向上している。しかし現
在のリチウムイオン電池と比べると、必ずしも十分なサ
イクル特性とは言えない。The charge / discharge cycle characteristics of a battery using a lithium metal negative electrode are certainly improved by the above-mentioned means known in the art. However, compared to current lithium-ion batteries, they do not always have sufficient cycle characteristics.
【００１０】そこで、本発明はデンドライト状リチウム
の発生を抑制することにより、リチウム金属負極を用い
て、高エネルギー密度を実現させ、かつ電池の充放電サ
イクル特性をさらに向上させたリチウム二次電池、リチ
ウムイオンの吸蔵、放出が可能な物質を負極に使用し、
急速充電を行っても長寿命なリチウム二次電池を提供す
ることを目的とするものである。Accordingly, the present invention provides a lithium secondary battery which realizes a high energy density and further improves the charge / discharge cycle characteristics of a battery by using a lithium metal negative electrode by suppressing the generation of dendritic lithium. Using a material that can store and release lithium ions for the negative electrode,
It is an object of the present invention to provide a lithium secondary battery that has a long life even when quick charging is performed.
【００１１】[0011]
【課題を解決するための手段】本発明は上記課題を解決
し、デンドライト状リチウムの発生を抑制して、サイク
ル寿命特性を向上させることにより、リチウム金属負極
を用いた場合、高エネルギー密度で長寿命のリチウム二
次電池を提供するものである。本発明では有機電解液中
にＣＯ2ガスを添加することで化学的にリチウム金属表
面部にＣＯ2を固定して、Ｌｉ2ＣＯ3皮膜を形成させ
る。さらに有機電解液中にマグネシウム元素を含有した
塩を添加することにより、電池充電時には溶解したマグ
ネシウムイオンがリチウム金属負極上の粒界部でとくに
優先的に還元されてマグネシウム金属が生成し、その場
でリチウム金属と反応することでその表面層において合
金を生成する、つまり表面に傾斜機能をもたせるもので
ある。その結果、Ｌｉ2ＣＯ3皮膜の効果と合金の相乗効
果により、単独の方法よりもさらにデンドライト状リチ
ウムの生成が抑制されて平滑に析出し、安全で長寿命か
つ高エネルギー密度電池が実現できるものである。SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, suppresses the generation of dendritic lithium, and improves the cycle life characteristics. It is intended to provide a long-life lithium secondary battery. In the present invention, CO 2 gas is added to the organic electrolytic solution to chemically fix CO 2 on the lithium metal surface to form a Li 2 CO 3 film. Furthermore, by adding a salt containing a magnesium element to the organic electrolyte, dissolved magnesium ions are preferentially reduced at the grain boundaries on the lithium metal negative electrode when the battery is charged, and magnesium metal is generated. Reacts with lithium metal to form an alloy in the surface layer, that is, the surface has a tilting function. As a result, due to the synergistic effect of the alloy and the effect of the Li 2 CO 3 film, the production of dendrite-like lithium is further suppressed as compared to the single method, and the lithium is deposited smoothly, and a safe, long-life and high energy density battery can be realized. It is.
【００１２】また、リチウムイオンを吸蔵したり放出し
たりする機能がある炭素材料負極を用いた場合におい
て、エネルギー密度は従来と同等で、マグネシウム塩と
ＣＯ2ガスを添加することで長寿命リチウムイオン二次
電池を実現することができる。この理由として、炭素材
料を負極に用いた場合にはデンドライト状リチウムの生
成は起きないが、特別な場合、すなわち充電電流密度を
増加して行う急速充電時においては炭素材料負極がリチ
ウムイオンを吸蔵しにくくなり、その結果デンドライト
状リチウムの生成が起こることがある。このため急速充
電を行ったリチウムイオン二次電池については、サイク
ル寿命特性が低下する。よって、有機電解質にマグネシ
ウム塩を添加することで、急速充電を行う場合について
も長寿命リチウムイオン二次電池を実現できる。この効
果は他のリチウムを吸蔵放出可能なポリマー、合金ある
いは金属化合物を負極に用いた場合でも同様に得られる
ものである。Further, when a carbon material negative electrode having a function of inserting and extracting lithium ions is used, the energy density is the same as that of the conventional one, and a long-life lithium ion is added by adding a magnesium salt and CO 2 gas. A secondary battery can be realized. The reason is that when a carbon material is used for the negative electrode, the generation of dendritic lithium does not occur, but in a special case, that is, during rapid charging performed by increasing the charging current density, the carbon material negative electrode absorbs lithium ions. , And as a result, formation of dendritic lithium may occur. For this reason, the cycle life characteristics of the lithium ion secondary battery that has been rapidly charged are reduced. Therefore, by adding the magnesium salt to the organic electrolyte, a long-life lithium-ion secondary battery can be realized even when quick charging is performed. This effect can be similarly obtained even when another polymer, alloy or metal compound capable of inserting and extracting lithium is used for the negative electrode.
【００１３】[0013]
【発明の実施の形態】本発明は、各請求項に記載する形
態によって実施できるものである。すなわち、請求項１
記載に係る発明のように、正極と、リチウム金属の負極
と、電池構成時にマグネシウム塩とＣＯ2ガスの両方を
含有する有機電解質を構成要素とすることにより実施し
得る。そして本発明によれば、少なくとも電池の充電時
に、リチウム金属負極においては、有機電解液中に溶存
しているＣＯ2ガスがリチウム金属表面部に固定され
て、Ｌｉ2ＣＯ3が生成される。またそれと同時に、マグ
ネシウムイオンが選択的にリチウム金属表面の粒界部で
還元、析出し、表面層においてリチウムと合金を生成す
る。そのため以降の充電ではリチウムデンドライトの生
成を抑制してサイクル寿命特性を向上させることができ
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be implemented by the embodiments described in the claims. That is, claim 1
As in the invention according to the description, the present invention can be implemented by using, as constituent elements, a positive electrode, a negative electrode of lithium metal, and an organic electrolyte containing both a magnesium salt and CO 2 gas when constituting a battery. According to the present invention, at least at the time of charging the battery, in the lithium metal negative electrode, the CO 2 gas dissolved in the organic electrolyte is fixed to the lithium metal surface, and Li 2 CO 3 is generated. At the same time, magnesium ions are selectively reduced and precipitated at the grain boundaries on the lithium metal surface, and form an alloy with lithium in the surface layer. Therefore, in the subsequent charging, the generation of lithium dendrite can be suppressed, and the cycle life characteristics can be improved.
【００１４】また、請求項２記載に係る発明のように、
負極にリチウム金属を使用しないで、リチウムイオンを
吸蔵したり、放出したりすることが可能な物質を負極と
して使用した場合においても、急速充電してもデンドラ
イト状リチウムが発生しないので長寿命リチウム二次電
池を実現することができる。Also, as in the invention according to claim 2,
Even when a material capable of occluding and releasing lithium ions is used as the negative electrode without using lithium metal for the negative electrode, even if the battery is rapidly charged, dendrite-like lithium is not generated. A secondary battery can be realized.
【００１５】また、請求項３記載に係る発明のように、
マグネシウム塩は、有機電解質中のリチウムイオン１ｍ
ｏｌに対し０．０１〜１ｍｏｌ含有させるようにすれば
良好な結果が得られる。Further, as in the invention according to claim 3,
Magnesium salt is 1m of lithium ion in organic electrolyte.
Good results can be obtained by adding 0.01 to 1 mol to ol.
【００１６】すなわち、マグネシウム塩のリチウムイオ
ン１ｍｏｌに対する添加量が０．０１ｍｏｌ以下である
とマグネシウム合金が充分に機能しない。また、マグネ
シウム塩の添加量が１ｍｏｌ以上であると、必要なリチ
ウムの析出よりもマグネシウムの析出が過剰に起こり、
リチウムイオンの析出、拡散が阻害されることにより、
高率充放電特性、低温充放電特性が低下するので好まし
くない。That is, if the addition amount of the magnesium salt to 1 mol of lithium ion is 0.01 mol or less, the magnesium alloy does not function sufficiently. Further, when the addition amount of the magnesium salt is 1 mol or more, precipitation of magnesium occurs more than required precipitation of lithium,
By inhibiting the deposition and diffusion of lithium ions,
It is not preferable because high-rate charge / discharge characteristics and low-temperature charge / discharge characteristics deteriorate.
【００１７】また、請求項４記載に係わる発明のよう
に、有機電解液の溶媒は、有機電解液単独であっても、
または有機電解液と高分子電解質の混合物であってもよ
い。Further, as in the invention according to claim 4, even if the solvent of the organic electrolytic solution is an organic electrolytic solution alone,
Alternatively, a mixture of an organic electrolyte and a polymer electrolyte may be used.
【００１８】また、請求項５記載に係る発明のように、
マグネシウム塩は、商業的に入手しやすいＭｇ（ＣｌＯ
4）2，ＭｇＳＯ4，Ｍｇ（ＰＯ4）2，ＭｇＢｒ2の中から
選ぶことが実際的である。Further, as in the invention according to claim 5,
Magnesium salts are commercially available Mg (ClO
It is practical to choose from 4 ) 2 , MgSO 4 , Mg (PO 4 ) 2 , and MgBr 2 .
【００１９】また、請求項６記載に係る発明のように、
ＣＯ2ガスは有機電解液１Ｌに対して、流量２Ｌ／分で
１〜５分間添加するようにすれば良好な結果が得られ
る。Further, as in the invention according to claim 6,
Good results can be obtained by adding CO 2 gas to 1 L of the organic electrolyte at a flow rate of 2 L / min for 1 to 5 minutes.
【００２０】すなわち、ＣＯ2ガスの有機電解液に対す
る添加量は１分間では２Ｌであり、これ以下の添加量で
はリチウム金属表面にＬｉ2ＣＯ3が生成しない。また、
添加時間５分間で有機電解液中のＣＯ2ガス濃度が飽和
に達するので、これ以上添加しても無駄になるばかりで
なく、時間当たりの有機電解液作成量が減少するので好
ましくない。That is, the addition amount of the CO 2 gas to the organic electrolyte is 2 L per minute, and if the addition amount is less than this, Li 2 CO 3 is not generated on the surface of the lithium metal. Also,
Since the CO 2 gas concentration in the organic electrolyte solution reaches saturation in 5 minutes of the addition time, the addition of more than this is not only wasteful but also decreases the amount of organic electrolyte solution produced per hour, which is not preferable.
【００２１】また、請求７記載に係る発明のように、負
極にリチウム金属を使用しないでリチウムイオンを吸蔵
したり放出したりすることが可能な物質を使う場合に
は、その物質として、ポリマー，炭素，黒鉛，金属酸化
物あるいは合金の中から選ぶことができる。In the case where a material capable of inserting and extracting lithium ions without using lithium metal is used for the negative electrode as in the invention according to claim 7, the material may be a polymer, You can choose from carbon, graphite, metal oxides or alloys.
【００２２】[0022]
【実施例】次に、本発明の具体例を図面とともに説明す
る。Next, a specific example of the present invention will be described with reference to the drawings.
【００２３】（実施例１）エチレンカーボネートとプロ
ピレンカーボネートを等体積量混合した溶媒に、電解質
であるＬｉＰＦ6を１ｍｏｌ／ｄｍ3となるように添加し
て調製した有機電解液を標準とした。前記有機電解液に
ＣＯ2ガスを１Ｌに対して、流量２Ｌ／分で５分間とＭ
ｇＢｒ2をリチウムイオン１ｍｏｌに対して１ｍｏｌ添
加して有機電解液Ａを得た。(Example 1) An organic electrolyte prepared by adding LiPF 6 as an electrolyte to a solvent in which ethylene carbonate and propylene carbonate are mixed in an equal volume to give a concentration of 1 mol / dm 3 was used as a standard. The amount of CO 2 gas in the organic electrolyte was 1 L, and the flow rate was 2 L / min for 5 minutes.
Organic electrolyte solution A was obtained by adding 1 mol of gBr 2 to 1 mol of lithium ions.
【００２４】＜電池性能評価＞図１にコイン型電池の構
成図を示す。図１において１は電池正極外装缶で電池負
極外装缶２との間にガスケット３を介して、内部に正極
４、負極５ならびにセパレータに含浸させた有機電解質
６を充填しているものである。<Evaluation of Battery Performance> FIG. 1 shows a configuration diagram of a coin-type battery. In FIG. 1, reference numeral 1 denotes a battery cathode outer can, which is filled with a cathode 4, an anode 5, and an organic electrolyte 6 impregnated in a separator via a gasket 3 between the battery anode outer can 2 and a battery anode outer can 2.
【００２５】図１のコイン型電池で、厚み０．３ｍｍで
１５φのリチウム金属からなる負極５と、厚み０．０８
ｍｍで１５φのＬｉＣｏＯ2からなる正極４を用い、正
極４と負極５との間に厚み２５μｍポリエチレン製セパ
レータに上記の有機電解液Ａを含浸させて有機電解質６
として、総高１．６ｍｍ、理論容量５ｍＡｈのコイン型
電池Ａを構成した。In the coin-type battery shown in FIG. 1, a negative electrode 5 made of lithium metal having a thickness of 15 mm and a thickness of 0.3 mm and a thickness of 0.08
A positive electrode 4 made of LiCoO 2 having a diameter of 15 mm is used. A 25 μm-thick polyethylene separator is impregnated with the organic electrolyte solution A between the positive electrode 4 and the negative electrode 5 to form an organic electrolyte 6.
As a result, a coin-type battery A having a total height of 1.6 mm and a theoretical capacity of 5 mAh was formed.
【００２６】（比較例）比較のため、ＣＯ2ガスもマグ
ネシウム塩も添加していない標準の有機電解液を用い
て、実施例１と同様にして、容量５ｍＡｈのコイン型電
池Ｂを構成した。Comparative Example For comparison, a coin-type battery B having a capacity of 5 mAh was constructed in the same manner as in Example 1 using a standard organic electrolyte solution to which neither CO 2 gas nor magnesium salt was added.
【００２７】図２にコイン型電池ＡおよびＢのサイクル
寿命特性を示す。試験条件は電池電圧が４．２Ｖになる
まで１ｍＡの電流で充電した後に定電圧充電に移行し、
４．２Ｖのまま容量５ｍＡｈになるまで充電を行った。
また放電は１ｍＡの電流で電池電圧が３．０Ｖに達する
まで行った。充電と放電との間の休止時間は５分間とし
た。サイクル寿命は理論容量に対して放電容量が６０％
に達したときとした。試験はすべて２０℃で行った。FIG. 2 shows the cycle life characteristics of the coin batteries A and B. The test conditions were as follows: the battery was charged at a current of 1 mA until the battery voltage reached 4.2 V, and then shifted to constant voltage charging.
The battery was charged at 4.2 V until the capacity reached 5 mAh.
The discharge was performed at a current of 1 mA until the battery voltage reached 3.0 V. The rest time between charge and discharge was 5 minutes. Cycle life is 60% of discharge capacity with respect to theoretical capacity
And when it reaches. All tests were performed at 20 ° C.
【００２８】図２より、従来品であるコイン型電池Ｂ
は、サイクル寿命が７０サイクルとなったが、本発明品
であるコイン型電池Ａは２００サイクルまで向上でき
た。FIG. 2 shows that the conventional coin-type battery B was used.
Although the cycle life was 70 cycles, the coin-type battery A of the present invention could be improved up to 200 cycles.
【００２９】（実施例２）エチレンカーボネートとプロ
ピレンカーボネートを等体積量混合した溶媒に、電解質
であるＬｉＰＦ6を１ｍｏｌ／ｄｍ3となるように調製し
た有機電解液を標準とした。前記有機電解液にＣＯ2ガ
スを１Ｌに対して、流量２Ｌ／分で５分間含有させ、Ｍ
ｇＢｒ2をリチウムイオン１ｍｏｌに対して１ｍｏｌ，
０．０１ｍｏｌ，１０ｍｏｌをそれぞれ添加し、有機電
解液Ａ，ＣおよびＤを得た。Example 2 An organic electrolyte prepared by mixing LiPF 6 as an electrolyte at 1 mol / dm 3 in a solvent in which ethylene carbonate and propylene carbonate were mixed in equal volumes was used as a standard. The organic electrolyte solution contains CO 2 gas at a flow rate of 2 L / min.
gBr 2 is 1 mol per 1 mol of lithium ion,
Organic electrolytes A, C and D were obtained by adding 0.01 mol and 10 mol, respectively.
【００３０】＜電池性能評価＞実施例１と同様にして、
厚み０．３ｍｍで１５φのリチウム金属からなる負極５
と、厚み０．０８ｍｍで１５φのＬｉＣｏＯ2からなる
正極４を用い、正極と負極との間に厚み２５μｍポリエ
チレン製セパレータに上記の有機電解液Ａ，ＣおよびＤ
をそれぞれ含浸させて有機電解質６とし、総高１．６ｍ
ｍ、理論容量５ｍＡｈのコイン型電池Ａ，ＣおよびＤを
構成した。<Evaluation of Battery Performance> In the same manner as in Example 1,
A negative electrode 5 made of lithium metal having a thickness of 0.3 mm and a diameter of 15φ
And a positive electrode 4 made of LiCoO 2 having a thickness of 0.08 mm and having a diameter of 15φ, and a 25 μm-thick polyethylene separator provided between the positive electrode and the negative electrode.
Are respectively impregnated into an organic electrolyte 6, and a total height of 1.6 m
m, coin type batteries A, C and D having a theoretical capacity of 5 mAh were constructed.
【００３１】（比較例）比較のため、ＣＯ2ガスもマグ
ネシウム塩も添加しない標準の有機電解液を用いて、実
施例２に示した電池Ａ，ＣおよびＤと同じ方法により容
量５ｍＡｈhのコイン型電池Ｂを構成した。また標準電
解液にＣＯ2ガスを１Ｌに対して、流量２Ｌ／分で５分
間含有させ、ＭｇＢｒ2をリチウムイオン１ｍｏｌに対
して０．００１ｍｏｌおよび２ｍｏｌ添加して有機電解
液ＥおよびＦを得て、実施例２に示した電池Ａ，Ｃおよ
びＤと同じ方法により容量５ｍＡｈのコイン型電池Ｅを
構成した。(Comparative Example) For comparison, a coin-type battery having a capacity of 5 mAah was prepared in the same manner as in the batteries A, C and D shown in Example 2 using a standard organic electrolyte solution to which neither CO 2 gas nor magnesium salt was added. Battery B was configured. The CO 2 gas in the standard electrolyte against 1L, is contained 5 minutes at a flow rate of 2L / min, to give an organic electrolyte E and F with 0.001mol and 2mol added MgBr 2 the lithium ion 1mol A coin-type battery E having a capacity of 5 mAh was formed in the same manner as the batteries A, C, and D shown in Example 2.
【００３２】図３にこれらコイン型電池のサイクル寿命
特性を示す。条件は実施例１と同様とし、電池電圧が
４．２Ｖになるまで１ｍＡの電流で充電した後に定電圧
充電に移行して、４．２Ｖのまま容量５ｍＡｈになるま
で充電を行った。また放電は１ｍＡの電流で電池電圧が
３．０Ｖに達するまで行った。充電と放電との間の休止
時間は５分間とした。サイクル寿命は理論容量に対して
放電容量が６０％に達したときとした。試験はすべて２
０℃で行った。FIG. 3 shows the cycle life characteristics of these coin-type batteries. The conditions were the same as in Example 1. After charging the battery with a current of 1 mA until the battery voltage reached 4.2 V, the operation was shifted to constant voltage charging, and charging was continued at 4.2 V until the capacity reached 5 mAh. The discharge was performed at a current of 1 mA until the battery voltage reached 3.0 V. The rest time between charge and discharge was 5 minutes. The cycle life was determined when the discharge capacity reached 60% of the theoretical capacity. All tests are 2
Performed at 0 ° C.
【００３３】図３より、標準品であるコイン型電池Ｂは
サイクル寿命が７０サイクルであるのに対して、コイン
型電池Ｃは１１０サイクルであった。寿命が低下するこ
とは防止できたが、本発明品であるコイン型電池Ａの２
００サイクルよりもその効果は小さい。またコイン型電
池Ｄは１２０サイクルであり、コイン型電池Ｂと比較し
て寿命が向上したが、本発明品であるコイン型電池Ａよ
りも効果は小さい。これは合金の生成によりリチウムデ
ンドライトは抑制できたが、必要なリチウムの析出より
もマグネシウムの析出が過剰に起るために、効果が相殺
されてサイクル寿命特性の著しい向上が見られないため
である。As shown in FIG. 3, the cycle life of the standard coin-type battery B was 70 cycles, while that of the coin-type battery C was 110 cycles. Although the life could be prevented from being shortened, the coin-type battery A of the present invention 2
The effect is smaller than in the 00 cycle. In addition, the coin-type battery D has 120 cycles and has a longer life than the coin-type battery B, but the effect is smaller than that of the coin-type battery A of the present invention. This is because lithium dendrite could be suppressed by the formation of the alloy, but the precipitation of magnesium occurred more excessively than the required precipitation of lithium, so the effect was canceled out and no significant improvement in cycle life characteristics was observed. .
【００３４】コイン型電池Ｅは７２サイクルであり、コ
イン型電池Ｂと同等であることから、コイン型電池Ｅの
添加量０．００１ｍｏｌでは効果がないと考えられる。
またコイン型電池Ｆは４５サイクルであり、コイン型電
池Ｂよりも低下した。これは添加量が２ｍｏｌと多すぎ
るためであると考える。Since the coin-type battery E has 72 cycles and is equivalent to the coin-type battery B, it is considered that an effect of 0.001 mol of the coin-type battery E is not effective.
Also, the coin-type battery F had 45 cycles, which was lower than that of the coin-type battery B. This is considered to be due to the added amount being as large as 2 mol.
【００３５】（実施例３）エチレンカーボネートとプロ
ピレンカーボネートを等体積量混合した溶媒に、電解質
であるＬｉＰＦ6を１ｍｏｌ／ｄｍ3となるように調製し
た有機電解液を標準とした。前記有機電解液にＣＯ2ガ
スを１Ｌに対して、流量２Ｌ／分で５分間とＭｇＢｒ2
をリチウムイオン１ｍｏｌに対して１ｍｏｌ添加して有
機電解液Ａを得た。Example 3 An organic electrolyte prepared by mixing LiPF 6 as an electrolyte at a concentration of 1 mol / dm 3 in a solvent in which ethylene carbonate and propylene carbonate were mixed in equal volumes was used as a standard. For 1 L of CO 2 gas in the organic electrolyte, the flow rate was 2 L / min for 5 minutes, and MgBr 2
Was added to 1 mol of lithium ion to obtain an organic electrolyte solution A.
【００３６】＜電池性能評価＞上記の方法で得た有機電
解液Ａを用いて、厚み０．３ｍｍで１５φのリチウム金
属からなる負極５と、厚み０．０８ｍｍで１５φのＬｉ
ＣｏＯ2からなる正極４を用い、正極と負極との間に厚
み２５μｍポリエチレン製セパレータを用いて、総高
１．６ｍｍ、理論容量５ｍＡｈのコイン型電池Ａを構成
した。<Evaluation of Battery Performance> Using the organic electrolytic solution A obtained by the above method, a negative electrode 5 made of lithium metal having a thickness of 15 mm and a thickness of 0.3 mm and a Li electrode having a thickness of 0.08 mm and a thickness of 15 φ
A coin-type battery A having a total height of 1.6 mm and a theoretical capacity of 5 mAh was formed using a positive electrode 4 made of CoO 2 and a 25-μm-thick polyethylene separator between the positive electrode and the negative electrode.
【００３７】（比較例）比較のため、標準の有機電解液
を用いて炭酸ガスを添加した後、ＭｇＢｒ2をリチウム
イオン１ｍｏｌに対して１ｍｏｌ添加するのは同じと
し、炭酸ガスを有機電解液１Ｌに対して、流量２Ｌ／分
で３０秒間、３０分間それぞれ添加した有機電解液Ｇお
よびＨを得た。そして実施例１と同様にして、容量５ｍ
Ａｈのコイン型電池ＧおよびＨを構成した。(Comparative Example) For comparison, it is the same to add carbon dioxide gas using a standard organic electrolyte solution and then add 1 mol of MgBr 2 to 1 mol of lithium ion. On the other hand, organic electrolytes G and H were added at a flow rate of 2 L / min for 30 seconds and 30 minutes, respectively. Then, in the same manner as in the first embodiment, the capacity is 5 m
Ah coin type batteries G and H were configured.
【００３８】図４にこれらコイン型電池のサイクル寿命
特性を示す。条件は実施例１と同様とし、電池電圧が
４．２Ｖになるまで１ｍＡの電流で充電した後に定電圧
充電に移行して、４．２Ｖのまま容量５ｍＡｈになるま
で充電を行った。また放電は１ｍＡの電流で電池電圧が
３．０Ｖに達するまで行った。充電と放電との間の休止
時間は５分間とした。サイクル寿命は理論容量に対して
放電容量が６０％に達したときとした。試験はすべて２
０℃で行った。FIG. 4 shows the cycle life characteristics of these coin-type batteries. The conditions were the same as in Example 1. After charging the battery with a current of 1 mA until the battery voltage reached 4.2 V, the operation was shifted to constant voltage charging, and charging was continued at 4.2 V until the capacity reached 5 mAh. The discharge was performed at a current of 1 mA until the battery voltage reached 3.0 V. The rest time between charge and discharge was 5 minutes. The cycle life was determined when the discharge capacity reached 60% of the theoretical capacity. All tests are 2
Performed at 0 ° C.
【００３９】図４より、コイン型電池Ｇはサイクル寿命
が７２サイクルとなったが、本発明品であるコイン型電
池Ａは２００サイクルまで向上できた。コイン型電池Ｇ
については寿命が低下することは防止できたが、コイン
型電池Ａよりもその効果は小さい。またコイン型電池Ｈ
も２２０サイクルまで寿命が改善された。しかし電池Ａ
と比較して電池特性では優位性がなく、コイン型電池Ｈ
を作成する場合、コイン型電池Ａと比較して電解液を作
成するのに６倍時間がかかり、量産性の点からは好まし
くなく、コイン型電池Ａが望ましいといえる。FIG. 4 shows that the cycle life of the coin-type battery G was 72 cycles, but the coin-type battery A of the present invention could be improved up to 200 cycles. Coin-cell battery G
Can be prevented from shortening the service life, but the effect is smaller than that of the coin-type battery A. Also coin-cell battery H
The life was improved up to 220 cycles. But battery A
There is no advantage in battery characteristics compared to
Is 6 times longer to prepare the electrolytic solution than the coin-type battery A, which is not preferable from the viewpoint of mass productivity, and it can be said that the coin-type battery A is preferable.
【００４０】（実施例４）エチレンカーボネートとプロ
ピレンカーボネートを等体積量混合した溶媒に、電解質
であるＬｉＰＦ6を１ｍｏｌ／ｄｍ3となるように調製し
た有機電解液を標準とした。前記有機電解液にＣＯ2ガ
スを１Ｌに対して、流量２Ｌ／分で５分間とＭｇＢｒ2
をリチウムイオン１ｍｏｌに対して１ｍｏｌ添加して有
機電解液Ａを得た。この有機電解液Ａを厚み２５μｍの
ポリエチレンオキシドに添加してゲル状高分子電解質Ｉ
を得た。Example 4 An organic electrolyte prepared by mixing LiPF 6 as an electrolyte at a concentration of 1 mol / dm 3 in a solvent in which ethylene carbonate and propylene carbonate were mixed in equal volumes was used as a standard. For 1 L of CO 2 gas in the organic electrolyte, the flow rate was 2 L / min for 5 minutes, and MgBr 2
Was added to 1 mol of lithium ion to obtain an organic electrolyte solution A. This organic electrolytic solution A was added to polyethylene oxide having a thickness of 25 μm to form a gel polymer electrolyte I.
I got
【００４１】＜電池性能評価＞上記の方法で得た有機電
解液Ａを用いて、実施例１と同様にして、厚み０．３ｍ
ｍで１５φのリチウム金属からなる負極５と、厚み０．
０８ｍｍで１５φのＬｉＣｏＯ2からなる正極４を用
い、正極と負極との間に厚み２５μｍポリエチレン製セ
パレータに上記方法で得た有機電解液Ａを含浸させ有機
電解質とし、総高１．６ｍｍ、理論容量５ｍＡｈのコイ
ン型電池Ａを構成した。<Evaluation of Battery Performance> Using the organic electrolyte solution A obtained by the above method, in the same manner as in Example 1, a thickness of 0.3 m
A negative electrode 5 made of lithium metal having a diameter of 15 m and a thickness of 0.
A positive electrode 4 made of LiCoO 2 having a diameter of 15 mm and a diameter of 15 mm was used, and a 25 μm-thick polyethylene separator was impregnated between the positive electrode and the negative electrode with the organic electrolyte solution A obtained by the above method to obtain an organic electrolyte. A coin-type battery A of 5 mAh was configured.
【００４２】また実施例１と同様にして、厚み０．３ｍ
ｍで１５φのリチウム金属からなる負極５と、厚み０．
０８ｍｍで１５φのＬｉＣｏＯ2からなる正極４を用
い、正極と負極との間に上記の方法で得たゲル状高分子
電解質Ｈを有機電解質とし、総高１．６ｍｍ、理論容量
５ｍＡｈのコイン型電池Ｉを構成した。In the same manner as in Example 1, the thickness was 0.3 m
A negative electrode 5 made of lithium metal having a diameter of 15 m and a thickness of 0.
A coin-type battery having a total height of 1.6 mm and a theoretical capacity of 5 mAh, using a positive electrode 4 made of LiCoO 2 having a diameter of 15 mm and a diameter of 15φ, and using the gel polymer electrolyte H obtained by the above method as an organic electrolyte between the positive electrode and the negative electrode. I was constructed.
【００４３】（比較例）比較のため、ＣＯ2ガスもマグ
ネシウム塩も添加しない標準の有機電解液を用いて、実
施例４に示した電池ＡおよびＩと同じ方法により容量５
ｍＡｈのコイン型電池Ｂを構成した。また標準電解液を
厚み２５μｍのポリエチレンオキシドに添加してゲル状
高分子電解質Ｊを得て、実施例４に示した電池Ａおよび
Ｉと同じ方法により容量５ｍＡｈのコイン型電池Ｊを構
成した。(Comparative Example) For comparison, using a standard organic electrolyte solution to which neither CO 2 gas nor magnesium salt was added, a capacity of 5 was obtained in the same manner as in the batteries A and I shown in Example 4.
A coin-type battery B of mAh was configured. A standard electrolytic solution was added to a 25 μm-thick polyethylene oxide to obtain a gel polymer electrolyte J. A coin-type battery J having a capacity of 5 mAh was constructed in the same manner as the batteries A and I shown in Example 4.
【００４４】図５にこれらコイン型電池のサイクル寿命
特性を示す。条件は実施例１と同様とし、電池電圧が
４．２Ｖになるまで１ｍＡの電流で充電した後に定電圧
充電に移行して、４．２Ｖのまま容量５ｍＡｈになるま
で充電を行った。また放電は１ｍＡの電流で電池電圧が
３．０Ｖに達するまで行った。充電と放電との間の休止
時間は５分間とした。サイクル寿命は理論容量に対して
放電容量が６０％に達したときとした。試験はすべて２
０℃で行った。FIG. 5 shows the cycle life characteristics of these coin-type batteries. The conditions were the same as in Example 1. After charging the battery with a current of 1 mA until the battery voltage reached 4.2 V, the operation was shifted to constant voltage charging, and charging was continued at 4.2 V until the capacity reached 5 mAh. The discharge was performed at a current of 1 mA until the battery voltage reached 3.0 V. The rest time between charge and discharge was 5 minutes. The cycle life was determined when the discharge capacity reached 60% of the theoretical capacity. All tests are 2
Performed at 0 ° C.
【００４５】図５よりコイン型電池Ｂはサイクル寿命が
７０サイクルであり、またコイン型電池Ｊの１００サイ
クルに対して、本発明品であるコイン型電池Ｉは２５０
サイクルであり、コイン型電池Ａの２００サイクルと比
較してもサイクル寿命特性は向上した。コイン型電池Ａ
と比較してサイクル寿命特性が向上した理由としては、
高分子電解質と有機電解質との性質の違いがある。高分
子電解質の方が固体状態であるので、デンドライト状リ
チウムを抑制でき、かつ電解質全面に電流が均一に流れ
るためにデンドライト状リチウムが発生しにくくなるた
めである。FIG. 5 shows that the coin-type battery B has a cycle life of 70 cycles, and the coin-type battery I of the present invention has a cycle life of 250 cycles with respect to 100 cycles of the coin-type battery J.
This was a cycle, and the cycle life characteristics were improved as compared with 200 cycles of the coin-type battery A. Coin type battery A
The reason why the cycle life characteristics were improved compared to
There is a difference in properties between the polymer electrolyte and the organic electrolyte. This is because, since the polymer electrolyte is in a solid state, the dendritic lithium can be suppressed, and the current flows uniformly over the entire surface of the electrolyte, so that the dendritic lithium is less likely to be generated.
【００４６】（実施例５）エチレンカーボネートとプロ
ピレンカーボネートを等体積量混合した溶媒に、電解質
であるＬｉＰＦ6を１ｍｏｌ／ｄｍ3となるように調製し
た有機電解液を標準とした。前記有機電解液にＣＯ2ガ
スを１Ｌに対して、流量２Ｌ／分で５分間とＭｇＢｒ2
をリチウムイオン１ｍｏｌに対して１ｍｏｌ添加して有
機電解液Ａを得た。Example 5 An organic electrolyte prepared by mixing LiPF 6 as an electrolyte at 1 mol / dm 3 in a solvent in which ethylene carbonate and propylene carbonate were mixed in equal volumes was used as a standard. For 1 L of CO 2 gas in the organic electrolyte, the flow rate was 2 L / min for 5 minutes, and MgBr 2
Was added to 1 mol of lithium ion to obtain an organic electrolyte solution A.
【００４７】＜電池性能評価＞実施例１と同様にして、
厚み０．３ｍｍで１５φのリチウム金属からなる負極５
と、厚み０．０８ｍｍで１５φのＬｉＣｏＯ2からなる
正極４を用い、正極と負極との間に厚み２５μｍポリエ
チレン製セパレータに上記方法で得た有機電解液Ａを含
浸させ有機電解質とし、総高１．６ｍｍ、理論容量５ｍ
Ａｈのコイン型電池Ａを構成した。<Evaluation of Battery Performance> In the same manner as in Example 1,
A negative electrode 5 made of lithium metal having a thickness of 0.3 mm and a diameter of 15φ
And a positive electrode 4 made of LiCoO 2 having a thickness of 0.08 mm and a diameter of 15φ, and a 25 μm-thick polyethylene separator was impregnated with the organic electrolyte solution A obtained by the above method between the positive electrode and the negative electrode to form an organic electrolyte. .6mm, theoretical capacity 5m
A coin-type battery A of Ah was constructed.
【００４８】また、同様にして厚み０．３ｍｍで１５φ
の炭素材料からなる負極５と、厚み０．０８ｍｍで１５
φのＬｉＣｏＯ2からなる正極４を用い、正極と負極と
の間に厚み２５μｍポリエチレン製セパレータを用い
て、総高１．６ｍｍ、理論容量５ｍＡｈのコイン型電池
Ｌを構成した。この場合、有機電解液Ａは使用できない
ので、プロピレンカーボネートの代りにジエチルカーボ
ネートを使用して、有機電解液Ｌを作成して用いた。そ
の理由としては、炭素負極とプロピレンカーボネートが
反応して、ガス発生を起こし電池を破裂させるためであ
る。Similarly, when the thickness is 0.3 mm and the diameter is 15 mm
Negative electrode 5 made of a carbon material of
A coin-type battery L having a total height of 1.6 mm and a theoretical capacity of 5 mAh was formed using a positive electrode 4 made of LiCoO 2 having a diameter of φ and a separator made of polyethylene having a thickness of 25 μm between the positive electrode and the negative electrode. In this case, since the organic electrolytic solution A cannot be used, an organic electrolytic solution L was prepared and used by using diethyl carbonate instead of propylene carbonate. The reason is that the carbon anode reacts with propylene carbonate to generate gas and rupture the battery.
【００４９】（比較例）比較のため、ＣＯ2ガスもマグ
ネシウム塩も添加しない標準の有機電解液Ｂを用いて、
実施例５に示した電池Ａと同じ方法により、容量５ｍＡ
ｈのコイン型電池Ｂを構成した。(Comparative Example) For comparison, a standard organic electrolytic solution B to which neither CO 2 gas nor magnesium salt was added was used.
By the same method as the battery A shown in Example 5, the capacity was 5 mA.
h coin type battery B was constructed.
【００５０】また、標準の有機電解液のうち、プロピレ
ンカーボネートの代りにジエチルカーボネートを使用し
た有機電解液Ｍを作製し、その有機電解液Ｍを用いて、
実施例５に示した電池Ｌと同じ方法により、容量５ｍＡ
ｈのコイン型電池Ｍを構成した。Further, among the standard organic electrolytic solutions, an organic electrolytic solution M using diethyl carbonate instead of propylene carbonate was prepared, and the organic electrolytic solution M was used.
By the same method as the battery L shown in Example 5, the capacity was 5 mA.
h coin type battery M was constructed.
【００５１】図６にこれら電池のサイクル寿命特性を示
す。条件は急速充電するために電池電圧が４．２Ｖにな
るまで３ｍＡの電流で充電した後に定電圧充電に移行し
て、４．２Ｖのまま容量５ｍＡｈになるまで充電を行っ
た。また放電は１ｍＡの電流で電池電圧が３．０Ｖに達
するまで行った。充電と放電との間の休止時間は５分間
とした。サイクル寿命は理論容量に対して放電容量が６
０％に達したときとした。試験はすべて２０℃で行っ
た。FIG. 6 shows the cycle life characteristics of these batteries. The conditions were as follows: for rapid charging, the battery was charged at a current of 3 mA until the battery voltage reached 4.2 V, and then the operation was shifted to constant voltage charging, and charging was continued at 4.2 V until the capacity reached 5 mAh. The discharge was performed at a current of 1 mA until the battery voltage reached 3.0 V. The rest time between charge and discharge was 5 minutes. The cycle life is 6 times the discharge capacity with respect to the theoretical capacity.
0% was reached. All tests were performed at 20 ° C.
【００５２】図６より、コイン型電池Ｂはサイクル寿命
が２０サイクルであり、またコイン型電池Ｍの５０サイ
クルに対して、本発明品であるコイン型電池Ｌは２００
サイクルであり、コイン型電池Ａの１５０サイクルと比
較してもサイクル寿命特性は向上した。急速充電ではデ
ンドライト状リチウムがより発生しやすくなるので、１
ｍＡの電流で充電した場合と比較してサイクル寿命特性
は低下する。また負極に炭素材料を用いたリチウムイオ
ン二次電池においてはこのサイズの場合、１ｍＡでの電
流では５００サイクル以上のサイクル寿命特性を示す
が、３ｍＡでの電流ではデンドライト状リチウムが発生
するためにサイクル寿命特性が低下する。しかし、本発
明品であるマグネシウム塩とＣＯ2ガスを添加すること
でデンドライト状リチウムの発生を抑制するので、サイ
クル寿命特性の低下を防止できる。リチウムイオン二次
電池については、初充放電において正極から炭素負極中
に取り込まれたまま、充放電に関与できないリチウムイ
オンが発生するので、理論容量よりも実容量は０．５ｍ
Ａ低下した。FIG. 6 shows that the coin-type battery B has a cycle life of 20 cycles, and the coin-type battery L of the present invention has a cycle life of 200 cycles compared to 50 cycles of the coin-type battery M.
This was a cycle, and the cycle life characteristics were improved as compared with 150 cycles of the coin-type battery A. In the case of rapid charging, dendrite-like lithium is more likely to be generated.
The cycle life characteristics are lower than when charged with a current of mA. In addition, a lithium ion secondary battery using a carbon material for the negative electrode shows a cycle life characteristic of 500 cycles or more at a current of 1 mA at a current of 1 mA, but a cycle of 3 mA at a current of 3 mA generates dendritic lithium. The life characteristics deteriorate. However, the addition of the magnesium salt and CO 2 gas of the present invention suppresses the generation of dendritic lithium, thereby preventing a decrease in cycle life characteristics. In the case of a lithium ion secondary battery, lithium ions which cannot be involved in charge / discharge are generated during the initial charge / discharge while being taken in from the positive electrode into the carbon negative electrode.
A decreased.
【００５３】なお、本発明の実施例においては、マグネ
シウム塩として、ＭｇＢｒ2を用いたが、Ｍｇ（Ｃｌ
Ｏ4）2やＭｇＳＯ4やＭｇ（ＰＯ4）2などであってもよ
い。In the embodiment of the present invention, MgBr 2 was used as the magnesium salt.
O 4 ) 2 , MgSO 4 , Mg (PO 4 ) 2, etc.
【００５４】また、電解質塩としてＬｉＰＦ6を用いた
が、ＬｉＢＦ4やＬｉＣｌＯ4などを用いてもよい。Although LiPF 6 is used as the electrolyte salt, LiBF 4 or LiClO 4 may be used.
【００５５】本発明の実施例においては、有機電解液溶
媒にエチレンカーボネート、プロピレンカーボネート、
ジエチルカーボネートを用いたが、ジメチルカーボネー
トやエチルメチルカーボネートなどの他の炭酸エステル
溶媒やジメトキシエタンなどのエーテル溶媒などであっ
てもよい。In the embodiment of the present invention, the solvent for the organic electrolyte is ethylene carbonate, propylene carbonate,
Although diethyl carbonate is used, other carbonate solvents such as dimethyl carbonate and ethyl methyl carbonate, and ether solvents such as dimethoxyethane may be used.
【００５６】また、本発明の実施例においては、高分子
電解質にポリエチレンオキシドを用いたが、ポリプロピ
レンオキシドなどのポリエーテル化合物や、ポリアクリ
ロニトリルなどであってもよい。Further, in the embodiments of the present invention, polyethylene oxide is used as the polymer electrolyte, but a polyether compound such as polypropylene oxide or polyacrylonitrile may be used.
【００５７】また、本発明の実施例においては、リチウ
ム二次電池正極としてＬｉＣｏＯ2を用いたが、ＬｉＮ
ｉＯ2やＬｉＭｎ2Ｏ4やＶ6Ｏ13などであってもよい。In the embodiment of the present invention, LiCoO 2 was used as the positive electrode of the lithium secondary battery.
iO 2 , LiMn 2 O 4 , V 6 O 13 or the like may be used.
【００５８】また、本発明の実施例においては、リチウ
ム二次電池負極としてリチウム金属と炭素材料を用いた
が、他のリチウムを吸蔵放出可能なポリマー、金属化合
物、合金などであってもよい。In the embodiments of the present invention, lithium metal and a carbon material are used as the negative electrode of the lithium secondary battery. However, other polymers, metal compounds, alloys and the like capable of inserting and extracting lithium may be used.
【００５９】[0059]
【発明の効果】以上のように本発明によれば、リチウム
二次電池において、有機電解質にＣＯ 2ガスと少なくと
も１種類以上のマグネシウム塩の両方を添加すること
で、サイクル寿命特性が向上し、かつ高エネルギー密度
のリチウム二次電池を作成することができる。As described above, according to the present invention, lithium
In a secondary battery, the organic electrolyte contains CO TwoGas and at least
Also add both one or more magnesium salts
With improved cycle life characteristics and high energy density
Lithium secondary battery can be produced.
【図１】本発明および比較例のコイン型電池の構成断面
図FIG. 1 is a cross-sectional view of a configuration of a coin-type battery of the present invention and a comparative example.
【図２】本発明および比較例のコイン型電池のサイクル
充放電特性を示す図FIG. 2 is a diagram showing cycle charge / discharge characteristics of coin batteries of the present invention and a comparative example.
【図３】本発明および比較例のコイン型電池のサイクル
充放電特性を示す図FIG. 3 is a diagram showing cycle charge / discharge characteristics of coin batteries of the present invention and a comparative example.
【図４】本発明および比較例のコイン型電池のサイクル
充放電特性を示す図FIG. 4 is a diagram showing cycle charge / discharge characteristics of coin type batteries of the present invention and a comparative example.
【図５】本発明および比較例のコイン型電池のサイクル
充放電特性を示す図FIG. 5 is a diagram showing cycle charge / discharge characteristics of coin batteries of the present invention and a comparative example.
【図６】本発明および比較例のコイン型電池のサイクル
充放電特性を示す図FIG. 6 is a diagram showing cycle charge / discharge characteristics of coin batteries of the present invention and a comparative example.
１ 電池負極外装缶 ２ 電池正極外装缶 ３ ガスケット ４ 負極 ５ 正極 ６ 有機電解質 Ａ コイン型電池Ａのサイクル充放電特性 Ｂ コイン型電池Ｂのサイクル充放電特性 Ｃ コイン型電池Ｃのサイクル充放電特性 Ｄ コイン型電池Ｄのサイクル充放電特性 Ｅ コイン型電池Ｅのサイクル充放電特性 Ｆ コイン型電池Ｆのサイクル充放電特性 Ｇ コイン型電池Ｇのサイクル充放電特性 Ｈ コイン型電池Ｈのサイクル充放電特性 Ｉ コイン型電池Ｉのサイクル充放電特性 Ｊ コイン型電池Ｊのサイクル充放電特性 Ｋ コイン型電池Ｋのサイクル充放電特性 Ｌ コイン型電池Ｌのサイクル充放電特性 Ｍ コイン型電池Ｍのサイクル充放電特性 REFERENCE SIGNS LIST 1 Battery negative case 2 Battery positive case 3 Gasket 4 Negative electrode 5 Positive electrode 6 Organic electrolyte A Cycle charge / discharge characteristics of coin battery A B Cycle charge / discharge characteristics of coin battery B C Cycle charge / discharge characteristics of coin battery C D Cycle charge / discharge characteristics of coin type battery D E Cycle charge / discharge characteristics of coin type battery E F Cycle charge / discharge characteristics of coin type battery F G Cycle charge / discharge characteristics of coin type battery G H Cycle charge / discharge characteristics of coin type battery H I Cycle charge / discharge characteristics of coin battery I J Cycle charge / discharge characteristics of coin battery J K Cycle charge / discharge characteristics of coin battery K L Cycle charge / discharge characteristics of coin battery L M Cycle charge / discharge characteristics of coin battery M
フロントページの続き (72)発明者 西村 賢 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 (72)発明者 石田 明子 大阪府門真市大字門真1006番地 松下電器 産業株式会社内Continuing on the front page (72) Inventor Ken Nishimura 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.
Claims (7)
時にマグネシウム塩とＣＯ2ガスの両方を含有する有機
電解質を構成要素とすることを特徴とするリチウム二次
電池。1. A lithium secondary battery comprising a positive electrode, a lithium metal negative electrode, and an organic electrolyte containing both a magnesium salt and CO 2 gas when constituting the battery.
したりすることが可能な物質からなる負極と、電池構成
時にマグネシウム塩とＣＯ2ガスの両方を含有する有機
電解質を構成要素とすることを特徴とするリチウム二次
電池。2. Components comprising a positive electrode, a negative electrode made of a substance capable of inserting and extracting lithium ions, and an organic electrolyte containing both a magnesium salt and CO 2 gas at the time of battery construction. A rechargeable lithium battery.
ムイオン１ｍｏｌに対して０．０１〜１ｍｏｌ含有され
ていることを特徴とする請求項１または２記載のリチウ
ム二次電池。3. The lithium secondary battery according to claim 1, wherein the magnesium salt is contained in an amount of 0.01 to 1 mol based on 1 mol of lithium ions in the organic electrolyte.
する有機電解質は、溶質と、有機電解液または有機電解
液と高分子電解質との混合物のいずれかとからなること
を特徴とする請求項１または２記載のリチウム二次電
池。4. An organic electrolyte containing both a magnesium salt and CO 2 gas comprises a solute and either an organic electrolyte or a mixture of an organic electrolyte and a polymer electrolyte. Or the lithium secondary battery according to 2.
ｇＳＯ4，Ｍｇ（ＰＯ4）2，ＭｇＢｒ2からなる群から選
ばれた少なくとも１つのマグネシウム塩であることを特
徴とする請求項１または２記載のリチウム二次電池。5. The magnesium salt is Mg (ClO 4 ) 2 , M
The lithium secondary battery according to claim 1, wherein the lithium secondary battery is at least one magnesium salt selected from the group consisting of gSO 4 , Mg (PO 4 ) 2 , and MgBr 2 .
量２Ｌ／分で１分間ないし５分間添加する請求項１また
は２記載のリチウム二次電池。6. The lithium secondary battery according to claim 1, wherein the CO 2 gas is added to 1 L of the organic electrolyte at a flow rate of 2 L / min for 1 minute to 5 minutes.
る機能を有する物質は、ポリマ，炭素，黒鉛，金属酸化
物および合金よりなる群から選ばれた物質であってリチ
ウムイオンを吸蔵したり放出したりする機能を有する物
質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。7. The substance having a function of occluding and releasing lithium ions is a substance selected from the group consisting of polymers, carbon, graphite, metal oxides and alloys, and occluding and releasing lithium ions. The lithium secondary battery according to claim 2, wherein the lithium secondary battery is a substance having a function of performing an operation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05169898A JP4250781B2 (en) | 1997-03-04 | 1998-03-04 | Lithium secondary battery |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9-48652 | 1997-03-04 | ||
| JP4865297 | 1997-03-04 | ||
| JP05169898A JP4250781B2 (en) | 1997-03-04 | 1998-03-04 | Lithium secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10308237A true JPH10308237A (en) | 1998-11-17 |
| JP4250781B2 JP4250781B2 (en) | 2009-04-08 |
Family
ID=26388954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05169898A Expired - Fee Related JP4250781B2 (en) | 1997-03-04 | 1998-03-04 | Lithium secondary battery |
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| Country | Link |
|---|---|
| JP (1) | JP4250781B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006278185A (en) * | 2005-03-30 | 2006-10-12 | Sanyo Electric Co Ltd | Lithium secondary battery and its producing method |
| CN110178254A (en) * | 2016-10-17 | 2019-08-27 | 伊利诺伊大学受托管理委员会 | Protected anode with and production and preparation method thereof |
-
1998
- 1998-03-04 JP JP05169898A patent/JP4250781B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006278185A (en) * | 2005-03-30 | 2006-10-12 | Sanyo Electric Co Ltd | Lithium secondary battery and its producing method |
| JP4739788B2 (en) * | 2005-03-30 | 2011-08-03 | 三洋電機株式会社 | Method for manufacturing lithium secondary battery |
| CN110178254A (en) * | 2016-10-17 | 2019-08-27 | 伊利诺伊大学受托管理委员会 | Protected anode with and production and preparation method thereof |
| EP3526846A4 (en) * | 2016-10-17 | 2020-12-09 | The Board of Trustees of the University of Illinois | Protected anodes and methods for making and using same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4250781B2 (en) | 2009-04-08 |
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