JPS6290868A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To obtain a nonaqueous electrolyte battery excellent in its low temperature discharge characteristic and storage characteristic, by using a mixed solvent including at least dioxolan and pyrrolidone. CONSTITUTION:N-methyl-Z-pyrrolidone or the like as pyrrolidne is used to capture cation of dioxolan produced during storage, suppress chain reaction, and inhibit the polymerization of dioxolan. By this process, degradation of electrolytic liquid is prevented. For example, an electrolyteic liquid is obtained by resolving 1mol/1 of lithium perchlorate into a mixed solvent of dioxolan and N-methyl-Z-pyrrolidone with a volume ratio of 1:0.001, and a positive electrode is made by mixing MnO2 from which water is removed, carbon powder, and fluororesin powder with a weight ratio of 85:10:5, and forming the mixture by pressure followed by heat processing. a negative electrode is made by a plate punched out from a rolled Li plate, and the flat nonaqueous electrolyte battery having good characteristics is obtained with nonwoven fabric of polypropylene as a separator.

Description

【発明の詳細な説明】 （イ）産業上の利用分野 本発明はリチウム又はリチウムを含む合金を負極活物質
とする非水電解液電池に関するものである。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a non-aqueous electrolyte battery using lithium or an alloy containing lithium as a negative electrode active material.

（ロ）従来の技術 この種電池の電解液は少くとも一つの溶媒と少くとも一
つの溶質とから構成きれている。そして溶媒としてはプ
ロピレンカーボネート、７−ブチロラクトン、ジメトキ
シエタン、スルホラン、テトラハイドロフランなどが一
般的なものであり、又溶質としては過塩素酸リチウム、
ホウフッ化リチウム、塩化リチウムなどが一般的である
。(b) Prior Art The electrolyte of this type of battery consists of at least one solvent and at least one solute. Common solvents include propylene carbonate, 7-butyrolactone, dimethoxyethane, sulfolane, and tetrahydrofuran, and solutes include lithium perchlorate,
Lithium borofluoride, lithium chloride, etc. are common.

箭して、近年に至っては溶媒として例えば特公昭５４−
１１８９０号公報或いは特公昭５８−５６４６６号公報
に開示きれているジオキソランが注目されている。However, in recent years, as a solvent, for example,
Dioxolane disclosed in Japanese Patent Publication No. 11890 or Japanese Patent Publication No. 58-56466 is attracting attention.

ジオキソランは他の溶媒に比して溶質の溶Ｍ度が大きく
、且低温での粘度が低いという利点を有するので低温特
性に優れた非水電解液電池を得ることができる。Dioxolane has the advantage of having a higher degree of solute solubility and lower viscosity at low temperatures than other solvents, so it is possible to obtain a non-aqueous electrolyte battery with excellent low-temperature characteristics.

ところが、ジオキソランは保存に伴いそのカチオンが生
成し、これが連鎖反応の開始剤となって長期保存後には
ジオキソランの重合が起って電解液の劣化を来たし電池
特性が低下する。However, dioxolane generates its cations as it is stored, and these cations act as initiators for chain reactions. After long-term storage, dioxolane polymerizes, leading to deterioration of the electrolyte and deterioration of battery characteristics.

くハ）発明が解決しようとする問題点 本発明は非水電解液電池の用途拡大に寄与すべく、特に
低温放電特性及び保存特性に優れた非水電解液電池を提
供することを目的とする。C) Problems to be Solved by the Invention The purpose of the present invention is to provide a non-aqueous electrolyte battery that has particularly excellent low-temperature discharge characteristics and storage characteristics, in order to contribute to expanding the uses of non-aqueous electrolyte batteries. .

（ニ）問題点を解決するための手段 本発明は電解液を構成する溶媒として少くともジオキソ
ランとピロリドンとを含む混合溶媒を用いることを特徴
とする。(d) Means for Solving the Problems The present invention is characterized in that a mixed solvent containing at least dioxolane and pyrrolidone is used as a solvent constituting the electrolytic solution.

（ホ）作用 本発明１池によれば、保存により生成せるジオキソラン
のカチオンをピロリドンが捕足し連鎖反応を抑えるため
ジオキソランの重合が阻止される。(E) Effect According to the first aspect of the present invention, pyrrolidone captures the cations of dioxolane produced during storage and suppresses the chain reaction, thereby inhibiting the polymerization of dioxolane.

尚、本発明に用いられるピロリドンとしては、Ｎ−メチ
ル−２−ピロリドン、Ｎ−エチル−２−ピロリドン、１
．５−ジメチル−２−ピロリドン或いはα−ピロリドン
が挙げられる。The pyrrolidone used in the present invention includes N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1
．． Examples include 5-dimethyl-2-pyrrolidone and α-pyrrolidone.

（へ）実施例 以下本発明の実施例につき詳述する。(f) Example Examples of the present invention will be described in detail below.

実施例１ 電解液組成ニジオキソランとＮ−メチル−２−ピロリド
ンとを１　：　０．００１の体積比で混合した混合溶媒
に溶質として過塩素酸リチウムを１モル／ｌ溶解したも
のを電解液とする。Example 1 Electrolyte composition The electrolyte was prepared by dissolving 1 mol/l of lithium perchlorate as a solute in a mixed solvent of dioxolane and N-methyl-2-pyrrolidone in a volume ratio of 1:0.001. do.

正極は水分除去のための熱処理を施した活物質としての
二酸化マンガンと、導電剤としてのカーボン粉末と、結
着剤としてのフッ素樹脂粉末とを８５：１０：５の重量
比で混合した正極合剤を加圧成型シ、つイテ２５０〜３
５０℃の温度で熱処理したものである。The positive electrode is a positive electrode composite made by mixing manganese dioxide as an active material that has been heat-treated to remove moisture, carbon powder as a conductive agent, and fluororesin powder as a binder in a weight ratio of 85:10:5. The agent is pressure molded, and the size is 250~3.
It was heat treated at a temperature of 50°C.

又、負極はリチウム圧延板を所定寸法に打抜いたものを
用い、セパレータはポリプロピレン不織布を用いて径２
Ｑ、Ｑａ、厚み２，５１１！Ｑ、電池容量１２０ｍＡＨ
の扁平型非水電解液電池を得た。In addition, the negative electrode is a lithium rolled plate punched out to a specified size, and the separator is made of polypropylene nonwoven fabric with a diameter of 2.
Q, Qa, thickness 2,511! Q. Battery capacity 120mAH
A flat non-aqueous electrolyte battery was obtained.

この電池を（Ａ１）とする。This battery is referred to as (A1).

比較例１ 電解液組成；ジオキソランの単独溶媒に溶質として過塩
素酸リチウムを１モル／１溶解したものを電解液とする
。Comparative Example 1 Electrolyte composition: An electrolyte solution was prepared by dissolving 1 mol/1 lithium perchlorate as a solute in a dioxolane sole solvent.

以下は実施例１と同様である。The following is the same as in Example 1.

この電池を（Ｂ１）とする。This battery is referred to as (B1).

第１図及び第２図はこれら電池（ＡＩ）（Ｂ、）の放電
特性を示し、第１図は初期放電特性、第２図は温度６０
°Ｃで３ケ月保存後の放電特性である。尚、放電条件は
温度−２０℃、負極３にΩとした。Figures 1 and 2 show the discharge characteristics of these batteries (AI) (B,), with Figure 1 showing the initial discharge characteristics and Figure 2 showing the temperature at 60°C.
This is the discharge characteristics after storage for 3 months at °C. Note that the discharge conditions were a temperature of -20° C. and a negative electrode 3 of Ω.

又、第３図は実施例１に示す二成分混合溶媒において、
ジオキソラン″１”に対するＮ−メチル−２−ピロリド
ンの混合比率と、６０”Ｃで３ケ月保存後の電池を一２
０’Ｃ１３にΩ負荷で放電した時の放電容量との関係を
示す、第３図からＮ−メゾルー２−ピロリドンの混合比
率としては１０”〜１０−５の範囲が好ましいことがわ
かる。In addition, FIG. 3 shows that in the two-component mixed solvent shown in Example 1,
The mixing ratio of N-methyl-2-pyrrolidone to ``1'' of dioxolane and the ratio of the battery after storage for 3 months at 60''C to 12
From FIG. 3, which shows the relationship with the discharge capacity when discharging at 0'C13 with an Ω load, it can be seen that the mixing ratio of N-mesol-2-pyrrolidone is preferably in the range of 10'' to 10-5.

次に、第３の溶媒として誘電率の高いプロピレンカーボ
ネートを加えた例を示す。Next, an example will be shown in which propylene carbonate, which has a high dielectric constant, is added as the third solvent.

実施例２ 電解液組成；ジオキソランとＮ−メチル−２−ピロリド
ンとプロピレンカーボネートとをに〇、００１：１の体
積比で混合した混合溶媒に溶質として過塩素酸リチウム
を１モル／ｌ溶解したものを寛解液とする。Example 2 Electrolyte composition: 1 mol/l of lithium perchlorate as a solute was dissolved in a mixed solvent of dioxolane, N-methyl-2-pyrrolidone, and propylene carbonate at a volume ratio of 1:1. is used as a remission solution.

以下は実施例１と同様である。The following is the same as in Example 1.

この電池を（Ａ、）とする。This battery is referred to as (A,).

比較例２ 電解液組成；ジオキソランとプロピレンカーボネートと
を１：１の体積比で混合した混合溶媒に溶質として過塩
素酸リチウムを１モル／ｐ、溶解したものを電解液とす
る。Comparative Example 2 Electrolyte composition: An electrolytic solution was prepared by dissolving 1 mol/p of lithium perchlorate as a solute in a mixed solvent in which dioxolane and propylene carbonate were mixed at a volume ratio of 1:1.

以下は実施例１と同様である。The following is the same as in Example 1.

この電池を（Ｂ、）とする。This battery is called (B,).

第４図及び第５図はこれら電池＜Ａ　ｌ＞（Ｂ　ｌ）の
放電特性を示し、第４図は初期放電特性、第５図は温度
６０℃で３ケ月保存後の放電特性である。尚、放電条件
は温度−２０°Ｃ１負荷３にΩとした。FIGS. 4 and 5 show the discharge characteristics of these batteries <A 1 >(B 1), with FIG. 4 showing the initial discharge characteristics and FIG. 5 showing the discharge characteristics after storage at a temperature of 60° C. for 3 months. Note that the discharge conditions were a temperature of -20°C, a load of 3, and Ω.

又、第６図は実施例２に示す三成分混合溶媒において、
ジオキソラン′１”及びプロピレンカーボネート“１”
に対するＮ−メチル−２−ピロリドンの混合比率と、６
０℃で３ケ月保存後の電池を一２０°Ｃ，３にΩ負荷で
放電した時の放電容量との関係を示す。第６図からＮ−
メチル−２−ピロリドンの混合比率としては１０−２〜
１０−５の範囲が好ましいことがわかる。Moreover, FIG. 6 shows that in the three-component mixed solvent shown in Example 2,
Dioxolane '1' and propylene carbonate '1'
The mixing ratio of N-methyl-2-pyrrolidone to 6
The relationship between the discharge capacity and the discharge capacity when a battery stored at 0°C for 3 months was discharged at -20°C with a 3Ω load is shown. From Figure 6 N-
The mixing ratio of methyl-2-pyrrolidone is 10-2~
It can be seen that a range of 10-5 is preferable.

尚、第３の溶媒としてプロピレンカーボネートの場合を
例示したが、プロピレンカーボネート以外に７−ブチロ
ラクトン、スルホラン、エチレンカーボネート、ジメト
キシエタン、テトラハイドロフランなども用いることが
できる。Although propylene carbonate is used as an example as the third solvent, 7-butyrolactone, sulfolane, ethylene carbonate, dimethoxyethane, tetrahydrofuran, etc. can also be used in addition to propylene carbonate.

第１図、第２図、第４図及び第５図から明らかなように
、本発明電池と比較電池とは初期放電特性ではほとんど
差異がないものの、保存特性においては本発明電池の方
が優れた特性を示すことがわかる。As is clear from Figures 1, 2, 4, and 5, although there is almost no difference in initial discharge characteristics between the battery of the present invention and the comparative battery, the battery of the present invention is superior in terms of storage characteristics. It can be seen that it exhibits certain characteristics.

この理由は保存により生成せるジオキソランのカチオン
をピロリドンが補足し連鎖反応を抑えるためジオキソラ
ンの重合が阻止され、その結果として電解液の劣化が抑
制されることに起因するものと考えられる。The reason for this is thought to be that pyrrolidone captures the cations of dioxolane produced during storage and suppresses chain reactions, thereby inhibiting dioxolane polymerization and, as a result, suppressing deterioration of the electrolyte.

（トン　発明の効果 上述した如く、溶媒として少くともジオキソランとピロ
リドンとを含む混合溶媒を用いることにより、低温放電
特性及び保存特性に優れた非水電解液電池を得ることが
できるものであり、この種電源の用途拡大に資するとこ
ろ極めて犬である。Effects of the Invention As mentioned above, by using a mixed solvent containing at least dioxolane and pyrrolidone as a solvent, it is possible to obtain a non-aqueous electrolyte battery with excellent low-temperature discharge characteristics and storage characteristics. It is extremely useful for expanding the uses of seed power sources.

【図面の簡単な説明】[Brief explanation of drawings]

第１図、第２ｒＸＪ、第４図及び第５図は本発明電池と
比較電池との放電特性比較図であり、第１図と第４図は
初期放電特性、第２図と第５図は保存特性を夫々示す。 又、第３図と第６図は各混合溶媒中におけるＮ−メチル
−２−ピロリドンの混合比率と電池の放電容量との関係
を示す。 （Ａ、ＸＡｔ）・・・本発明電池、（Ｂ、）（Ｂ２）・
・・比較電池。Figure 1, Figure 2rXJ, Figure 4 and Figure 5 are diagrams comparing the discharge characteristics of the battery of the present invention and the comparative battery. Figures 1 and 4 are initial discharge characteristics, Figures 2 and 5 are The storage characteristics are shown respectively. Further, FIGS. 3 and 6 show the relationship between the mixing ratio of N-methyl-2-pyrrolidone in each mixed solvent and the discharge capacity of the battery. (A, XAt)...Battery of the present invention, (B,) (B2)
・Comparison battery.

Claims (1)

【特許請求の範囲】[Claims] （１）リチウム又はリチウムを含む合金を活物質とする
負極と、正極と、少くとも一つの溶媒と少くとも一つの
溶質とからなる非水電解液とを備えるものであって、溶
媒が少くともジオキソランとピロリドンとを含む混合溶
媒であることを特徴とする非水電解液電池。(1) A device comprising a negative electrode using lithium or an alloy containing lithium as an active material, a positive electrode, and a non-aqueous electrolyte comprising at least one solvent and at least one solute, where the solvent is at least A nonaqueous electrolyte battery characterized by using a mixed solvent containing dioxolane and pyrrolidone.