JPH07211349A - Nonaqueous electrolyte secondary battery - Google Patents
Nonaqueous electrolyte secondary batteryInfo
- Publication number
- JPH07211349A JPH07211349A JP6005845A JP584594A JPH07211349A JP H07211349 A JPH07211349 A JP H07211349A JP 6005845 A JP6005845 A JP 6005845A JP 584594 A JP584594 A JP 584594A JP H07211349 A JPH07211349 A JP H07211349A
- Authority
- JP
- Japan
- Prior art keywords
- battery
- lithium
- nonaqueous electrolyte
- aqueous electrolyte
- electrolytic solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電解液の溶質として、
六フッ化リン酸リチウムを用いた非水電解液二次電池に
おける非水電解液に関するものである。The present invention relates to a solute of an electrolytic solution,
The present invention relates to a non-aqueous electrolytic solution in a non-aqueous electrolytic solution secondary battery using lithium hexafluorophosphate.
【０００２】[0002]
【従来の技術】近年、エレクトロニクスの進歩により携
帯電話、ラップトップパソコン等の電子機器の小型化が
盛んに行われており、電源としての電池に高容量化、高
出力化が切望されている。これに対応する電池として
は、高容量化されたニッケルカドミウム電池やニッケル
水素電池等が開発されてきた。2. Description of the Related Art In recent years, electronic devices such as mobile phones and laptop personal computers have been actively miniaturized due to the progress of electronics, and there has been a strong demand for higher capacity and higher output of batteries as a power source. As a battery corresponding to this, a high capacity nickel cadmium battery, a nickel hydrogen battery, or the like has been developed.
【０００３】しかしながら、カメラ一体型ＶＴＲ等で
は、さらなる軽量化、高エネルギー密度化等が要求され
ており、リチウムイオンを吸蔵、放出する非水電解液二
次電池が最近になって特に有望視されている。However, in a camera-integrated VTR and the like, further weight reduction and higher energy density are demanded, and a non-aqueous electrolyte secondary battery which absorbs and releases lithium ions has recently been particularly promising. ing.
【０００４】非水電解液二次電池の負極材料には、リチ
ウムイオンを結晶中にドーピングしたカーボンの層間化
合物あるいは黒鉛層間化合物があり、正極活物質に関し
ては、代表的な活物質として、特開昭６３−５９５０７
号公報、特開昭６３−２９９０５６号公報等にＬｉＣｏ
Ｏ2、ＬｉＮｉＯ2等が記載されている。この正極活物質
を使用した非水電解液二次電池の場合、放電電圧が３．
５〜４．０Ｖと一次電池に比べて高い放電電圧を有する
ことが示されている。As a negative electrode material of a non-aqueous electrolyte secondary battery, there is an intercalation compound of carbon or a graphite intercalation compound in which crystals are doped with lithium ions, and regarding a positive electrode active material, as a typical active material Sho 63-59507
Japanese Patent Laid-Open No. 63-299056, LiCo.
O 2 , LiNiO 2 and the like are described. In the case of a non-aqueous electrolyte secondary battery using this positive electrode active material, the discharge voltage is 3.
It is shown to have a discharge voltage of 5 to 4.0 V, which is higher than that of the primary battery.
【０００５】このような材料を使用した電池の放電反応
では、負極材料のリチウムイオンが、正極活物質である
上記材料の層間にインターカレーションすることによっ
て進行し、逆に充電反応では、上記材料の層間からリチ
ウムイオンが負極へデインターカレーションが生じてい
る。このように負極のリチウムイオンが正極活物質の層
間に出入りする反応を繰り返すことによって、充放電を
繰り返すことができる。In the discharge reaction of the battery using such a material, lithium ions of the negative electrode material proceed by intercalating between the layers of the above material which is the positive electrode active material, and conversely in the charging reaction, the above material is discharged. Lithium ions are deintercalated from the interlayer to the negative electrode. By repeating the reaction in which the lithium ions of the negative electrode come in and out between the layers of the positive electrode active material in this manner, charging and discharging can be repeated.
【０００６】そして、このような非水電解液二次電池の
電解液として、有機溶媒に電解質を溶解した非水電解液
が使用されている。ここで、非水電解液二次電池に用い
られる電解質としては、高伝導度を持つ六フッ化リン酸
リチウム（ＬｉＰＦ6）が一般的に用いられている。A non-aqueous electrolytic solution prepared by dissolving an electrolyte in an organic solvent is used as an electrolytic solution for such a non-aqueous electrolytic solution secondary battery. Here, as the electrolyte used in the non-aqueous electrolyte secondary battery, lithium hexafluorophosphate (LiPF 6 ) having high conductivity is generally used.
【０００７】又、フッ素を含有する溶質としては、他に
ホウフッ化リチウム（ＬｉＢＦ4）、トリフルオロメタ
ンスルホン酸リチウム（ＬｉＣＦ3ＳＯ3）等がある。Other solutes containing fluorine include lithium borofluoride (LiBF 4 ) and lithium trifluoromethanesulfonate (LiCF 3 SO 3 ).
【０００８】しかしながら、このようなフッ素を含有す
る溶質の中でもＬｉＰＦ6は、水分に対する安定性が特
に悪いので、極微量の水分が存在するだけでも、この水
分と反応して、フッ酸を発生する。このフッ酸によっ
て、電池缶の腐食を引き起こすだけでなく、活物質であ
るリチウムを消費してしまいＬｉＦを形成して、電池容
量を低下させるという問題があった。However, among such solutes containing fluorine, LiPF 6 is particularly poor in stability against water, so that even a very small amount of water reacts with this water to generate hydrofluoric acid. . This hydrofluoric acid not only causes corrosion of the battery can, but also consumes lithium that is an active material to form LiF, resulting in a problem that the battery capacity is reduced.
【０００９】[0009]
【発明が解決しようとする課題】本発明は、上述のよう
な問題を解決し、ＬｉＰＦ6を電解質とする電解液を用
いた非水電解液二次電池において、保存特性に優れ、内
部抵抗が小さく、電池特性の優れた非水電解液二次電池
を提供するものである。The present invention solves the above problems and provides a non-aqueous electrolyte secondary battery using an electrolyte containing LiPF 6 as an electrolyte, which has excellent storage characteristics and internal resistance. A small non-aqueous electrolyte secondary battery having excellent battery characteristics is provided.
【００１０】具体的には、金属酸化物かななるフッ素吸
着剤で処理した電解液を用いることによって、電解液中
の遊離フッ素濃度が低減され、保存中におけるＦ-とＬ
ｉ+との反応を抑制でき、電池内部抵抗の増大を抑制す
ることができる。Specifically, by using an electrolytic solution treated with a fluorine adsorbent such as a metal oxide, the free fluorine concentration in the electrolytic solution is reduced, and F − and L − during storage are reduced.
The reaction with i + can be suppressed, and the increase in internal resistance of the battery can be suppressed.
【００１１】[0011]
【課題を解決するための手段】本発明の非水電解液二次
電池は、リチウム金属又はリチウムイオンを吸蔵・放出
可能な負極と、リチウム含有複合酸化物を主活物質とす
る正極と、溶質と溶媒からなる非水電解液とを備え、前
記溶質が六フッ化リン酸リチウムであり、且つ、前記非
水電解液はフッ素吸着剤による処理工程を行った非水電
解液であることを特徴とする。A non-aqueous electrolyte secondary battery of the present invention comprises a negative electrode capable of inserting and extracting lithium metal or lithium ions, a positive electrode containing a lithium-containing composite oxide as a main active material, and a solute. And a non-aqueous electrolyte solution comprising a solvent, the solute is lithium hexafluorophosphate, and the non-aqueous electrolyte solution is a non-aqueous electrolyte solution subjected to a treatment step with a fluorine adsorbent And
【００１２】又、前記フッ素吸着剤が金属酸化物である
ことが好ましい。Further, the fluorine adsorbent is preferably a metal oxide.
【００１３】さらに、前記金属酸化物が酸化アルミニウ
ム、酸化ケイ素、酸化マグネシウムのうちから選ばれる
少なくとも１種であることが好ましい。Further, the metal oxide is preferably at least one selected from aluminum oxide, silicon oxide and magnesium oxide.
【００１４】[0014]
【作用】本発明者等は、ＬｉＣｏＯ2、ＬｉＮｉＯ2等の
リチウム含有複合酸化物を正極活物質、リチウムの吸
蔵、放出可能な炭素材を負極、非水電解液の溶質にＬｉ
ＰＦ6を用いた非水電解液二次電池のサイクル特性、充
電保存特性の向上を目的として、種々の実験検討を行っ
た。The present inventors have found that a lithium-containing composite oxide such as LiCoO 2 or LiNiO 2 is used as a positive electrode active material, a carbon material capable of occluding and releasing lithium is used as a negative electrode, and a solute of a non-aqueous electrolytic solution is used as a solute.
Various experiments were conducted for the purpose of improving the cycle characteristics and the charge storage characteristics of the non-aqueous electrolyte secondary battery using PF 6 .
【００１５】まず、非水電解液に関して、溶質には、Ｌ
ｉＰＦ6を使用しているので、このリチウム塩を良好に
溶解させるために、溶媒として用いられるものは、高誘
電率溶媒であることが必要である。First, regarding the non-aqueous electrolyte, the solute is L
Since iPF 6 is used, it is necessary for the solvent used to be a solvent having a high dielectric constant in order to dissolve the lithium salt well.
【００１６】この高誘電率溶媒としては、エチレンカー
ボネート（ＥＣ）、γ−ブチロラクトン（γ−ＢＬ）、
スルホラン（ＳＬ：テトラヒドロチオフェン−１，１−
ジオキシド）等が用いられる。As the high dielectric constant solvent, ethylene carbonate (EC), γ-butyrolactone (γ-BL),
Sulfolane (SL: tetrahydrothiophene-1,1-
Dioxide) and the like are used.
【００１７】さらに、高誘電率溶媒だけでは、低温特性
が悪くなるので、低温特性を向上させるためには低沸点
溶媒が必要である。Further, since the low-temperature characteristic is deteriorated only by the high dielectric constant solvent, a low boiling point solvent is required to improve the low-temperature characteristic.
【００１８】低沸点溶媒としては、ジメチルカーボネー
ト（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、メチ
ルエチルカーボネート（ＭＥＣ）、１，２−ジメトキシ
エタン（ＤＭＥ）、１，２−ジエトキシエタン（ＤＥ
Ｅ）、１，２−ジブトキシエタン（ＤＢＥ）、エトキシ
メトキシエタン（ＥＭＥ）等が用いられる。As the low boiling point solvent, dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DE)
E), 1,2-dibutoxyethane (DBE), ethoxymethoxyethane (EME) and the like are used.
【００１９】このように非水電解液としては、高誘電溶
媒の内から少なくとも一種類と、低沸点溶媒の内から少
なくとも一種類とを混合して使用される。As described above, as the non-aqueous electrolyte, a mixture of at least one kind from the high dielectric solvent and at least one kind from the low boiling point solvent is used.
【００２０】高誘電率溶媒と低沸点溶媒との体積混合比
率は、非水電解液の全体積に対して、高誘電率溶媒を３
０％〜７０％の比率で混合させることが好ましい。The volume mixing ratio of the high dielectric constant solvent and the low boiling point solvent is such that the high dielectric constant solvent is 3 with respect to the total volume of the non-aqueous electrolyte.
It is preferable to mix them in a ratio of 0% to 70%.
【００２１】本発明は、このようにして得られた非水電
解液を、電池内に注液する前に、除湿アルゴン雰囲気下
でフッ素吸着用金属酸化物を充填したクロマトグラム用
の円筒ガラス容器内に通過させたものである。The present invention provides a cylindrical glass container for a chromatogram filled with a metal oxide for adsorbing fluorine in a dehumidified argon atmosphere before injecting the thus obtained non-aqueous electrolyte into a battery. It has been passed inside.
【００２２】このように非水電解液がフッ素吸着用金属
酸化物内を通過すると、非水電解液の有機溶媒中に残存
している微量水分によって、フッ素含有電解質が反応し
て発生する遊離酸と、もともと電解質中に残存していた
遊離酸とを、金属酸化物が吸着することができるので、
非水電解液中の遊離酸濃度を低減させることができる。When the non-aqueous electrolyte passes through the fluorine-adsorbing metal oxide in this way, the free acid generated by the reaction of the fluorine-containing electrolyte by the trace amount of water remaining in the organic solvent of the non-aqueous electrolyte. And, since the metal oxide can adsorb the free acid that originally remained in the electrolyte,
The free acid concentration in the non-aqueous electrolyte can be reduced.
【００２３】したがって、このフッ素吸着剤による処理
後の非水電解液を電池内に注液しても、あらかじめ電解
液中の遊離フッ素が除去されているので、遊離フッ素と
充電負極内のリチウムとの反応がないので、リチウムが
消費されることがない。その結果、保存後の放電容量が
低下することなく保存特性が向上する。Therefore, even if the non-aqueous electrolytic solution after the treatment with the fluorine adsorbent is poured into the battery, the free fluorine in the electrolytic solution has been removed in advance, so that the free fluorine and the lithium in the charging negative electrode are removed. Since there is no reaction of, lithium is not consumed. As a result, the storage characteristics are improved without lowering the discharge capacity after storage.
【００２４】さらに、遊離フッ素とリチウムとの反応に
よって生じる反応生成物で不働態であるフッ化リチウム
が存在しないので、内部抵抗の増加を抑制することがで
き、サイクル特性が向上する。Furthermore, since there is no passive lithium fluoride in the reaction product generated by the reaction between free fluorine and lithium, it is possible to suppress an increase in internal resistance and improve cycle characteristics.
【００２５】尚、非水電解液をクロマトグラム用の円筒
ガラス内にフッ素吸着用金属酸化物を充填して通過させ
たが、クロマトグラム以外の他の方法でも同様の効果を
生じる。Although the nonaqueous electrolytic solution was filled with the metal oxide for adsorbing fluorine in the cylindrical glass for the chromatogram and passed through, the same effect can be obtained by a method other than the chromatogram.
【００２６】[0026]
［実施例１］ 〔正極の作製〕正極活物質としてＬｉＣｏＯ2を８５重
量部、人造黒鉛粉末８重量部、カーボンブラック２重量
部とを充分混合した後、Ｎ−メチル−２−ピロリドンに
溶かしたＰＶｄＦを固形分として５重量部となるように
加えインク状の正極スラリーとした。Example 1 [Production of Positive Electrode] 85 parts by weight of LiCoO 2 as a positive electrode active material, 8 parts by weight of artificial graphite powder, and 2 parts by weight of carbon black were thoroughly mixed and then dissolved in N-methyl-2-pyrrolidone. PVdF was added to a solid content of 5 parts by weight to obtain an ink-like positive electrode slurry.
【００２７】この正極スラリーを長さ３５５ｍｍ、幅４
０ｍｍ、厚さ２０μｍのアルミ箔上に両面塗布し、乾燥
後、ローラープレス機により圧延し、端部にアルミニウ
ムのリードを超音波溶着した後、１１０℃で３時間真空
乾燥処理して、正極を作製した。This positive electrode slurry has a length of 355 mm and a width of 4
Both sides are coated on an aluminum foil having a thickness of 0 mm and a thickness of 20 μm, dried, rolled by a roller press machine, ultrasonically welded to an end of an aluminum lead, and then vacuum dried at 110 ° C. for 3 hours to obtain a positive electrode. It was made.
【００２８】〔負極の作製〕負極として、粒子径５〜２
５μｍの天然黒鉛粉末９５重量部、Ｎ−メチル−２−ピ
ロリドンに溶かしたＰＶｄＦを固形分として５重量部と
なるように加えインク状の負極スラリーとした。[Preparation of Negative Electrode] As the negative electrode, the particle size is 5 to 2
95 parts by weight of 5 μm natural graphite powder and 5 parts by weight of PVdF dissolved in N-methyl-2-pyrrolidone as solid content were added to obtain an ink-like negative electrode slurry.
【００２９】この負極スラリーを長さ３８５ｍｍ、幅４
０ｍｍ、厚さ１８μｍの銅箔上に両面塗布し、乾燥後、
ローラープレス機により圧延し、端部にニッケルのリー
ドをスポット溶接した後、１１０℃で３時間真空乾燥処
理して、負極を作製した。This negative electrode slurry has a length of 385 mm and a width of 4
Both sides are coated on a copper foil with a thickness of 0 mm and a thickness of 18 μm, and after drying,
After rolling with a roller press and spot welding of nickel leads to the ends, vacuum drying treatment was performed at 110 ° C. for 3 hours to produce a negative electrode.
【００３０】〔電解液の調整〕１ｍｏｌ／ｄｍ3の濃度
になるようにＬｉＰＦ6をＥＣとＤＭＣとの体積混合比
が１：１である混合溶媒に溶解して非水電解液を調整し
た。[Preparation of Electrolytic Solution] LiPF 6 was dissolved in a mixed solvent having a volume mixing ratio of EC and DMC of 1: 1 to prepare a non-aqueous electrolytic solution so that the concentration was 1 mol / dm 3 .
【００３１】次に、この非水電解液を、酸化マグネシウ
ムを充填したガラスカラム内に通してフッ素吸着剤によ
る処理を行った。Next, this non-aqueous electrolyte was passed through a glass column filled with magnesium oxide and treated with a fluorine adsorbent.
【００３２】〔電池の作製〕上記の正極と負極とを、厚
さ２５μｍの多孔性ポリプロピレン製セパレータを介し
て渦巻状に巻き取り、渦巻電極体を作製した。[Preparation of Battery] The above positive electrode and negative electrode were spirally wound with a porous polypropylene separator having a thickness of 25 μm interposed therebetween to prepare a spiral electrode body.
【００３３】この渦巻電極体を、ニッケルメッキを施し
た鉄製の電池缶内に挿入した後、上記フッ素吸着処理を
施した電解液を注液した。The spirally wound electrode body was inserted into a nickel-plated iron battery can, and then the above-mentioned fluorine-adsorbed electrolytic solution was injected.
【００３４】次いで、電池缶の開口部にガスケットを介
した封口体によって、封口して直径１４ｍｍ、高さ５０
ｍｍサイズの密閉円筒型電池を作製した。この密閉円筒
型電池を本発明電池Ａ１とする。Then, the opening of the battery can was sealed with a sealing body via a gasket, and the diameter was 14 mm and the height was 50 mm.
A mm size sealed cylindrical battery was produced. This sealed cylindrical battery is referred to as Battery A1 of the invention.
【００３５】尚、この本発明電池Ａ１の電解液の遊離酸
濃度を測定したところ、２０ｐｐｍであった。The free acid concentration of the electrolytic solution of Battery A1 of the invention was 20 ppm.
【００３６】［実施例２］電解液のフッ素吸着剤として
使用する金属酸化物として、酸化アルミニウムを使用す
る以外は、実施例１と同様にして、電池を作製した。こ
の電池を本発明電池Ａ２とする。Example 2 A battery was produced in the same manner as in Example 1 except that aluminum oxide was used as the metal oxide used as the fluorine adsorbent in the electrolytic solution. This battery is referred to as Battery A2 of the invention.
【００３７】尚、この本発明電池Ａ２の電解液の遊離酸
濃度を測定したところ、２５ｐｐｍであった。The free acid concentration of the electrolytic solution of Battery A2 of the invention was 25 ppm.
【００３８】［実施例３］電解液のフッ素吸着剤として
使用する金属酸化物として、酸化マグネシウムと酸化ケ
イ素の１：１の混合物を使用する以外は、実施例１と同
様にして、電池を作製した。この電池を本発明電池Ａ３
とする。Example 3 A battery was prepared in the same manner as in Example 1 except that a 1: 1 mixture of magnesium oxide and silicon oxide was used as the metal oxide used as the fluorine adsorbent in the electrolytic solution. did. This battery is the present invention battery A3.
And
【００３９】尚、この本発明電池Ａ３の電解液の遊離酸
濃度を測定したところ、２０ｐｐｍであった。The free acid concentration of the electrolytic solution of Battery A3 of the invention was 20 ppm.
【００４０】［比較例１］電解液のフッ素吸着剤による
処理工程を行わなかった以外は、実施例１と同様にし
て、電池を作製した。この電池を比較電池Ｘ１とする。[Comparative Example 1] A battery was prepared in the same manner as in Example 1 except that the step of treating the electrolytic solution with the fluorine adsorbent was not carried out. This battery is referred to as a comparative battery X1.
【００４１】尚、この比較電池Ｘ１の電解液の遊離酸濃
度を測定したところ、７０ｐｐｍであった。The free acid concentration of the electrolytic solution of this comparative battery X1 was measured and found to be 70 ppm.
【００４２】［比較例２］電解液のフッ素吸着剤による
処理工程を行わず、電解液に酸化マグネシウムを添加す
る以外は、実施例１と同様にして、電池を作製した。こ
の電池を比較電池Ｘ２とする。[Comparative Example 2] A battery was produced in the same manner as in Example 1 except that magnesium oxide was added to the electrolytic solution without performing the step of treating the electrolytic solution with the fluorine adsorbent. This battery is referred to as a comparative battery X2.
【００４３】尚、この比較電池Ｘ２の電解液の遊離酸濃
度を測定したところ、２０ｐｐｍであった。The free acid concentration of the electrolytic solution of this comparative battery X2 was measured and found to be 20 ppm.
【００４４】［実験１］本発明電池Ａ１、Ａ２及びＡ
３、比較電池Ｘ１及びＸ２を用いて、サイクル特性を測
定した。測定条件は、充電電流５００ｍＡで電池電圧が
４．２Ｖに達するまで充電し、放電電流５００ｍＡで電
池電圧が２．５Ｖに達するまで放電するという一連のサ
イクルを繰り返して行った。[Experiment 1] Inventive batteries A1, A2 and A
3. Using the comparative batteries X1 and X2, cycle characteristics were measured. The measurement was performed by repeating a series of cycles of charging at a charging current of 500 mA until the battery voltage reached 4.2 V and discharging at a discharging current of 500 mA until the battery voltage reached 2.5 V.
【００４５】この結果を図１に示す。図１より、本発明
電池Ａ１、Ａ２及びＡ３は比較電池Ｘ１及びＸ２と比較
して、サイクル特性の劣化が抑制されていることが判
る。これは、サイクル中の各電池の表面の温度を測定し
たところ、約４５℃まで上昇しており、高温時に、遊離
酸が存在すると充電状態のＬｉと反応してＬｉが不活性
化してしまい充放電容量が低下するので、本発明電池Ａ
１、Ａ２及びＡ３のように、遊離酸濃度が低いほど上述
のような問題がなくサイクル特性が向上すると考えられ
る。The results are shown in FIG. From FIG. 1, it is understood that the batteries A1, A2 and A3 of the present invention have suppressed deterioration of cycle characteristics as compared with the comparative batteries X1 and X2. This is because when the temperature of the surface of each battery during the cycle was measured, it increased to about 45 ° C, and at the time of high temperature, if free acid is present, Li reacts with Li in the charged state and Li becomes inactive, and the charge is reduced. Since the discharge capacity is reduced, the present invention battery A
As in Nos. 1, A2 and A3, it is considered that the lower the free acid concentration, the more the above problems do not occur and the cycle characteristics improve.
【００４６】又、遊離酸濃度は、本発明電池Ａ１、Ａ
２、Ａ３及び比較電池Ｘ２とも同程度であるが、比較電
池Ｘ２のように電解液に直接酸化マグネシウムのような
金属酸化物を添加すると、この金属酸化物によりセパレ
ータの目詰まりが生じて、内部抵抗を増加させ、サイク
ル特性を低下させる問題がある。さらに、セパレータが
破断して内部ショートを起こすという問題もある。The free acid concentration is determined by the batteries A1 and A of the present invention.
2, A3 and the comparative battery X2 are similar, but when a metal oxide such as magnesium oxide is directly added to the electrolytic solution as in the comparative battery X2, the metal oxide causes clogging of the separator and There is a problem that resistance is increased and cycle characteristics are deteriorated. Further, there is a problem that the separator is broken and an internal short circuit occurs.
【００４７】［実験２］次に、本発明電池Ａ１、Ａ２及
びＡ３、比較電池Ｘ１及びＸ２を用いて、高温保存前後
の充放電容量を比較して充放電効率を測定した。[Experiment 2] Next, using the batteries A1, A2 and A3 of the present invention and comparative batteries X1 and X2, the charge and discharge capacities before and after high temperature storage were compared to measure the charge and discharge efficiency.
【００４８】測定条件としては、保存前に、充電電流１
５０ｍＡで電池電圧が４．２Ｖに達するまで充電した
後、放電電流５００ｍＡで電池電圧が２．５Ｖに達する
まで放電したときの容量を測定する。As a measurement condition, a charging current of 1 before storage
After charging at 50 mA until the battery voltage reaches 4.2 V, the capacity when discharging at 500 mA until the battery voltage reaches 2.5 V is measured.
【００４９】次に、この電池を充電電流５００ｍＡで電
池電圧が４．２Ｖに達するまで充電し、６０℃の雰囲気
下でこの充電状態の電池を３日間保存した後、放電電流
５００ｍＡで電池電圧２．５Ｖに達するまで放電したと
きの容量を測定して、保存前の容量に対してどれだけ放
電（放電効率）できたかを測定する。（黒印）そして、
充電電流５００ｍＡで電池電圧４．２Ｖに達するまでの
充電量を測定して、初期保存前の充電量と比較する（充
電効率）。（白抜き印）各保存後の放電効率と充電効率
を図２に示した。Next, this battery was charged at a charging current of 500 mA until the battery voltage reached 4.2 V, and the battery in this charged state was stored for 3 days in an atmosphere of 60 ° C., then at a discharging current of 500 mA, a battery voltage of 2 The capacity at the time of discharging until reaching 0.5 V is measured, and how much the discharge (discharge efficiency) can be performed with respect to the capacity before storage is measured. (Black mark) And
The amount of charge until the battery voltage reaches 4.2 V at a charging current of 500 mA is measured and compared with the amount of charge before initial storage (charging efficiency). (Open mark) The discharge efficiency and the charging efficiency after each storage are shown in FIG.
【００５０】図２から、本発明電池Ａ１、Ａ２及びＡ３
は比較電池Ｘ１及びＸ２と比較して、保存後の放電効率
が高いことが判る。これは、本発明電池Ａ１、Ａ２及び
Ａ３はそれぞれ自己放電が少ないからであると考えられ
る。さらに、比較電池Ｘ１及びＸ２は保存回数が増加す
ると、充電効率が悪くなり、保存後、充電しても最初に
あった充電量まで回復しなくなっている。しかしなが
ら、本発明電池では、高温保存後における保存回数の増
加に対しても充電すれば、最初の充電量近くまで充電す
ることができる。From FIG. 2, the batteries A1, A2 and A3 of the present invention are shown.
It can be seen that the discharge efficiency after storage is higher than that of the comparative batteries X1 and X2. This is considered to be because each of the batteries A1, A2, and A3 of the present invention has less self-discharge. Further, in the comparative batteries X1 and X2, when the number of times of storage increases, the charging efficiency becomes poor, and even after charging after storage, the charge amount that was initially present cannot be recovered. However, the battery of the present invention can be charged up to a level close to the initial charge amount by charging even when the number of times of storage after high temperature storage is increased.
【００５１】このように、電解液に存在する遊離酸と充
電状態のＬｉとの反応による活物質の不働態化は、高温
での保存によって、より顕著に現れ、充電及び放電効率
に悪影響を及ぼすが、本発明では、この活物質の不働態
化を抑制することができ、高温保存後でも充放電効率の
低下を抑制することができる。As described above, the passivation of the active material due to the reaction between the free acid existing in the electrolytic solution and the Li in the charged state becomes more prominent when stored at high temperature, which adversely affects the charging and discharging efficiency. However, in the present invention, the passivation of this active material can be suppressed, and the decrease in charge / discharge efficiency can be suppressed even after storage at high temperature.
【００５２】[0052]
【発明の効果】本発明は、溶質にフッ素を含有する非水
電解液をフッ素吸着剤による処理工程によって、非水電
解液内に存在する遊離酸及び、非水電解液に残存してい
る水分とフッ素含有電解質とが反応して発生した遊離酸
とを減少させることができる。INDUSTRIAL APPLICABILITY According to the present invention, the free acid present in the nonaqueous electrolytic solution and the water remaining in the nonaqueous electrolytic solution are treated by the step of treating the nonaqueous electrolytic solution containing fluorine as a solute with a fluorine adsorbent. It is possible to reduce the amount of free acid generated by the reaction between the fluorine-containing electrolyte and the electrolyte.
【００５３】したがって、この遊離酸によって負極のリ
チウムが消費されることなく、保存特性の低下を防止す
ることができ、又、遊離酸とリチウムの反応によって生
じるリチウムの不働態化を抑制することができ、電池の
内部抵抗の増加を抑制でき、サイクル特性を向上させる
ことができる。Therefore, the free acid does not consume lithium in the negative electrode, and it is possible to prevent the deterioration of the storage characteristics, and to suppress the passivation of lithium caused by the reaction between the free acid and lithium. Therefore, the internal resistance of the battery can be prevented from increasing and the cycle characteristics can be improved.
【図１】本発明電池及び比較電池のサイクル特性を示す
図である。FIG. 1 is a diagram showing cycle characteristics of a battery of the present invention and a comparative battery.
【図２】本発明電池と比較電池の充放電効率を示す図で
ある。FIG. 2 is a diagram showing charge / discharge efficiency of the battery of the present invention and the comparative battery.
本発明電池・・・・・・Ａ１、Ａ２、Ａ３ 比較電池・・・・・・・Ｘ１、Ｘ２ Inventive battery: A1, A2, A3 Comparative battery: X1, X2
Claims (3)
・放出可能な負極と、リチウム含有複合酸化物を主活物
質とする正極と、溶質と溶媒からなる非水電解液とを備
え、前記溶質が六フッ化リン酸リチウムであり、且つ、
前記非水電解液はフッ素吸着剤による処理工程を行った
非水電解液であることを特徴とする非水電解液二次電
池。1. A negative electrode capable of occluding and releasing lithium metal or lithium ions, a positive electrode having a lithium-containing composite oxide as a main active material, and a non-aqueous electrolytic solution containing a solute and a solvent, wherein the solute is 6 Lithium fluorophosphate, and
The non-aqueous electrolyte secondary battery is characterized in that the non-aqueous electrolyte is a non-aqueous electrolyte subjected to a treatment step with a fluorine adsorbent.
とを特徴とする請求項１記載の非水電解液二次電池。2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the fluorine adsorbent is a metal oxide.
化ケイ素、酸化マグネシウムのうちから選ばれる少なく
とも１種であることを特徴とする請求項２記載の非水電
解液二次電池。3. The non-aqueous electrolyte secondary battery according to claim 2, wherein the metal oxide is at least one selected from aluminum oxide, silicon oxide, and magnesium oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6005845A JPH07211349A (en) | 1994-01-24 | 1994-01-24 | Nonaqueous electrolyte secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6005845A JPH07211349A (en) | 1994-01-24 | 1994-01-24 | Nonaqueous electrolyte secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07211349A true JPH07211349A (en) | 1995-08-11 |
Family
ID=11622356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6005845A Pending JPH07211349A (en) | 1994-01-24 | 1994-01-24 | Nonaqueous electrolyte secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07211349A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2761531A1 (en) * | 1997-03-25 | 1998-10-02 | Ube Industries | Non-aqueous electrolyte solution for lithium battery |
| WO2000013251A1 (en) * | 1998-08-31 | 2000-03-09 | Hitachi, Ltd. | Lithium secondary cell and device |
| WO2010098497A1 (en) * | 2009-02-24 | 2010-09-02 | 帝人株式会社 | Porous membrane for nonaqueous secondary battery, separator for nonaqueous secondary battery, adsorbent for nonaqueous secondary battery, and nonaqueous secondary battery |
| US8361653B2 (en) | 2009-08-28 | 2013-01-29 | Sharp Kabushiki Kaisha | Non-aqueous electrolyte secondary battery |
| KR101438696B1 (en) * | 2008-01-31 | 2014-09-05 | 삼성에스디아이 주식회사 | Electrode Assembly and Secondary Battery having the Same |
-
1994
- 1994-01-24 JP JP6005845A patent/JPH07211349A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2761531A1 (en) * | 1997-03-25 | 1998-10-02 | Ube Industries | Non-aqueous electrolyte solution for lithium battery |
| US6045945A (en) * | 1997-03-25 | 2000-04-04 | Ube Industries, Ltd. | Electrolyte solution for lithium secondary battery |
| WO2000013251A1 (en) * | 1998-08-31 | 2000-03-09 | Hitachi, Ltd. | Lithium secondary cell and device |
| KR101438696B1 (en) * | 2008-01-31 | 2014-09-05 | 삼성에스디아이 주식회사 | Electrode Assembly and Secondary Battery having the Same |
| WO2010098497A1 (en) * | 2009-02-24 | 2010-09-02 | 帝人株式会社 | Porous membrane for nonaqueous secondary battery, separator for nonaqueous secondary battery, adsorbent for nonaqueous secondary battery, and nonaqueous secondary battery |
| US8361653B2 (en) | 2009-08-28 | 2013-01-29 | Sharp Kabushiki Kaisha | Non-aqueous electrolyte secondary battery |
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