JP2006286570A - Nonaqueous electrolyte for lithium secondary battery and lithium secondary battery having it - Google Patents
Nonaqueous electrolyte for lithium secondary battery and lithium secondary battery having it Download PDFInfo
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Abstract
Description
本発明は、リチウム二次電池用非水電解液及びそれを備えたリチウム二次電池に関し、特に高い導電率と難燃性とを有するリチウム二次電池用非水電解液及び優れた負荷特性と安全性とを有するリチウム二次電池に関するものである。 The present invention relates to a non-aqueous electrolyte for a lithium secondary battery and a lithium secondary battery including the same, and in particular, a non-aqueous electrolyte for a lithium secondary battery having high conductivity and flame retardancy, and excellent load characteristics. The present invention relates to a lithium secondary battery having safety.
負極として黒鉛等の炭素材料を用い、正極としてＬｉＣｏＯ2等のリチウム遷移金属複合酸化物を用いたリチウムイオン電池は、高い電圧と高エネルギー密度を有する二次電池として、現在ノート型パソコン及び携帯電話等の駆動電源として広く用いられている。更に今後は、上記の炭素系の負極材料に比ベ、単位重量或いは単位体積当りの理論エネルギー密度の大きなリチウムやリチウム合金を負極活物質として用いたリチウム二次電池が、さらなる高エネルギー二次電池として実用化されることが期待されている。 Lithium ion batteries using carbon materials such as graphite as the negative electrode and lithium transition metal composite oxides such as LiCoO 2 as the positive electrode are currently used as notebook computers and mobile phones as secondary batteries having high voltage and high energy density. It is widely used as a drive power source. Further, in the future, lithium secondary batteries using lithium or lithium alloys having a large theoretical energy density per unit weight or unit volume as a negative electrode active material in comparison with the above-described carbon-based negative electrode materials will be further high energy secondary batteries. It is expected to be put to practical use.
しかしながら、リチウムやリチウム合金を負極活物質として用いた場合、充放電の繰返しによりリチウム金属の不均一な電析・溶解が進行し、リチウムが樹枝状に成長するデンドライトの問題がある。発生したデンドライトは、電池性能の低下を招くだけでなく、正負極間に配置したセパレーターを貫通して電池をショートさせることもある。一般に、これら二次電池の電解液としては、エステル化合物及びエーテル化合物等の可燃性有機溶媒が使用されており、最悪の場合には発熱、発火に至ることがあるため、リチウム二次電池実用化にあたっては、上述のリチウムイオン電池よりさらに高い安全性が求められる。 However, when lithium or a lithium alloy is used as the negative electrode active material, there is a problem of dendrite in which lithium metal is non-uniformly deposited and dissolved by repeated charge and discharge, and lithium grows in a dendritic shape. The generated dendrite not only degrades the battery performance, but also may cause the battery to short through the separator disposed between the positive and negative electrodes. In general, flammable organic solvents such as ester compounds and ether compounds are used as the electrolyte of these secondary batteries, and in the worst case, they may generate heat and ignite. In this case, safety higher than that of the above-described lithium ion battery is required.
これに対して、電池の安全性を向上させるために、電解液を難燃化する方法が検討されており、例えば、電解液にリン酸トリメチル等のリン酸エステル類を用いたり、非プロトン性有機溶媒にリン酸エステル類を添加したりする方法が提案されている（特許文献１〜３参照）。しかしながら、これら一般的なリン酸トリエステル類は、必ずしも難燃性が高くないため、十分な難燃効果を発現させるためには、その配合量を増加させる必要がある。 On the other hand, in order to improve the safety of the battery, a method for making the electrolyte solution flame-retardant has been studied. For example, a phosphate ester such as trimethyl phosphate is used for the electrolyte solution, or aprotic A method of adding phosphate esters to an organic solvent has been proposed (see Patent Documents 1 to 3). However, these general phosphoric acid triesters do not necessarily have high flame retardancy, and therefore it is necessary to increase the blending amount in order to achieve a sufficient flame retardant effect.
ところが、電解液中の上記リン酸トリエステル類の配合量が増大するに従い電解液の導電率が低下すると共に、上記リン酸トリエステル類は電気化学的に安定な物質ではないため、充放電を繰り返すことで徐々に負極で還元分解され、充放電効率などの電池特性が大きく劣化してしまう問題がある。特に、高負荷条件である高い電流密度（ハイレート）での充放電においては、低配合量であってもリン酸トリエステルの還元分解が進行し易く充放電容量の低下が著しい。 However, as the amount of the phosphate triesters in the electrolyte increases, the conductivity of the electrolyte decreases, and the phosphate triesters are not electrochemically stable substances. By repeating, there is a problem that the battery is gradually reduced and decomposed at the negative electrode, and battery characteristics such as charge / discharge efficiency are greatly deteriorated. In particular, in charge / discharge at a high current density (high rate) which is a high load condition, the reductive decomposition of the phosphoric acid triester easily proceeds even at a low blending amount, and the charge / discharge capacity is significantly reduced.
このように、従来の技術では、リチウム二次電池の負荷特性と安全性とを高度に両立することができなかった。 Thus, with the conventional technology, it has been impossible to achieve a high balance between the load characteristics and safety of the lithium secondary battery.
そこで、本発明の目的は、上記従来技術の問題を解決し、高い難燃性と導電率とを有するリチウム二次電池用非水電解液及び優れた負荷特性と安全性とを有するリチウム二次電池を提供することにある。 Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, a non-aqueous electrolyte for a lithium secondary battery having high flame retardancy and electrical conductivity, and a lithium secondary having excellent load characteristics and safety. To provide a battery.
本発明者は、上記目的を達成するために鋭意検討した結果、特定構造のリン酸エステルを含む非水溶媒を利用することにより、高い難燃性と高い導電率とを併せ持つ電解液が得られるとともに、これを用いることで、リチウム二次電池の安全性及び負荷特性を大幅に改善できることを見出し、本発明を完成させるに至った。 As a result of intensive studies to achieve the above object, the present inventor can obtain an electrolyte solution having both high flame retardancy and high conductivity by using a non-aqueous solvent containing a phosphate ester having a specific structure. Together with this, it has been found that the safety and load characteristics of the lithium secondary battery can be greatly improved, and the present invention has been completed.
即ち、本発明のリチウム二次電池用非水電解液は、非水溶媒及び支持塩を含み、リチウム又はその合金を負極に用いたリチウム二次電池用の非水電解液であって、
下記一般式(I)：
［式中、Ｒ1は、それぞれ独立してフッ素、アルコキシ基又はアリールオキシ基であり、２つのＲlのうち少なくとも一つはアルコキシ基又はアリールオキシ基であり、但し、２つのＲ1は互いに結合して環を形成してもよい］で表されるフルオロリン酸エステル化合物を20体積％以上含むことを特徴とする。
That is, the non-aqueous electrolyte for a lithium secondary battery of the present invention is a non-aqueous electrolyte for a lithium secondary battery containing a non-aqueous solvent and a supporting salt, and using lithium or an alloy thereof as a negative electrode,
The following general formula (I):
[Wherein R 1 is independently a fluorine, alkoxy group or aryloxy group, and at least one of the two R 1 is an alkoxy group or aryloxy group, provided that two R 1 are It may be bonded to form a ring], and contains 20% by volume or more of a fluorophosphate ester compound represented by
本発明のリチウム二次電池用非水電解液の好適例においては、前記一般式(I)中の２つのＲlのうち１つがフッ素であり、他の１つがアルコキシ基又はアリールオキシ基である。この場合、非水電解液が、特に低粘度で且つ安全性に優れる。 In a preferred example of the non-aqueous electrolyte for a lithium secondary battery of the present invention, one of the two R l in the general formula (I) is fluorine, and the other is an alkoxy group or an aryloxy group. . In this case, the non-aqueous electrolyte has particularly low viscosity and excellent safety.
本発明のリチウム二次電池用非水電解液は、更に下記一般式(II)：
［式中、Ｒ2は、それぞれ独立して水素、フッ素又は炭素数１〜２のアルキル基である］で表される不飽和環状エステル化合物を含むことが好ましい。この場合、リチウム二次電池の負荷特性を更に向上させることができる。ここで、上記一般式(II)で表される不飽和環状エステル化合物の含有量は、前記非水電解液全体の0.1〜10質量％であることが好ましい。
The non-aqueous electrolyte for a lithium secondary battery of the present invention is further represented by the following general formula (II):
It is preferable that the unsaturated cyclic ester compound represented by [In formula, R < 2 > is each independently hydrogen, a fluorine, or a C1-C2 alkyl group]. In this case, the load characteristics of the lithium secondary battery can be further improved. Here, the content of the unsaturated cyclic ester compound represented by the general formula (II) is preferably 0.1 to 10% by mass of the whole non-aqueous electrolyte.
また、本発明のリチウム二次電池は、上記の非水電解液と、正極と、リチウム又はその合金を用いた負極とを備えることを特徴とする。 Moreover, the lithium secondary battery of the present invention is characterized by comprising the above non-aqueous electrolyte, a positive electrode, and a negative electrode using lithium or an alloy thereof.
本発明によれば、電解液に上記式(I)のフルオロリン酸エステル化合物を用いることにより、配合量が増加しても導電率及び電気化学的安定性に優れ、かつ高い難燃性を発現する電解液が得られる。これにより負荷特性に優れ、破裂、発火、引火の危険性が大幅に抑制された、すなわち安全性が著しく改善されたリチウム二次電池を提供することができる。 According to the present invention, by using the fluorophosphate ester compound of the above formula (I) in the electrolytic solution, even when the blending amount is increased, the conductivity and electrochemical stability are excellent, and high flame retardancy is expressed. To obtain an electrolytic solution. Accordingly, it is possible to provide a lithium secondary battery that has excellent load characteristics and has greatly reduced risk of rupture, ignition, and ignition, that is, significantly improved safety.
理由は必ずしも明らかではないが、上記式(I)のフルオロリン酸エステル化合物は、通常のリン酸トリエステルより分子サイズが小さく、またリン−フッ素結合による分子間力の低減効果が低粘度化に寄与し、さらには特有の分子構造がリチウムイオンの解離を高め、電解液の導電率を向上させるものと考えられる。さらに、式(I)のフルオロリン酸エステル化合物が有するリン−フッ素結合がリン酸エステル分子全体の耐還元性を向上させると共に、熱分解時には不燃化に有効なガス成分を発生し、高い難燃性を発現するものと考えられる。 Although the reason is not necessarily clear, the fluorophosphate ester compound of the above formula (I) has a smaller molecular size than a normal phosphate triester, and the effect of reducing intermolecular force due to the phosphorus-fluorine bond is reduced in viscosity. In addition, it is considered that the unique molecular structure increases the dissociation of lithium ions and improves the conductivity of the electrolyte. Furthermore, the phosphorus-fluorine bond of the fluorophosphate ester compound of formula (I) improves the reduction resistance of the entire phosphate ester molecule, and generates a gas component effective for incombustibility during pyrolysis, resulting in high flame resistance. It is considered to express sex.
＜リチウム二次電池用非水電解液＞
以下に、本発明のリチウム二次電池用非水電解液を詳細に説明する。本発明のリチウム二次電池用非水電解液は、上記一般式(I)で表されるフルオロリン酸エステル化合物を含む非水溶媒と支持塩とからなり、更に非水溶媒として非プロトン性溶媒を含んでもよい。
<Non-aqueous electrolyte for lithium secondary battery>
Below, the nonaqueous electrolyte for lithium secondary batteries of this invention is demonstrated in detail. The non-aqueous electrolyte for a lithium secondary battery of the present invention comprises a non-aqueous solvent containing a fluorophosphate ester compound represented by the above general formula (I) and a supporting salt, and an aprotic solvent as a non-aqueous solvent May be included.
本発明のリチウム二次電池用非水電解液に含まれるフルオロリン酸エステル化合物は、上記一般式(I)で表される。式(I)において、Ｒlは、それぞれ独立してフッ素、アルコキシ基又はアリールオキシ基であり、２つのＲlのうち少なくとも一つはアルコキシ基又はアリールオキシ基である。 The fluorophosphate ester compound contained in the non-aqueous electrolyte for a lithium secondary battery of the present invention is represented by the above general formula (I). In the formula (I), R 1 is each independently fluorine, an alkoxy group or an aryloxy group, and at least one of the two R 1 is an alkoxy group or an aryloxy group.
式(I)のＲlにおけるアルコキシ基としては、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基等や、二重結合を含むアリルオキシ基等、更にはメトキシエトキシ基、メトキシエトキシエトキシ基等のアルコキシ置換アルコキシ基等が挙げられる。これらのアルコキシ基中の水素元素は、ハロゲン元素で置換されていてもよく、フッ素で置換されていることが好ましい。これらの中でも、難燃性、低粘度に優れる点で、メトキシ基、エトキシ基、トルフルオロエトキシ基、プロポキシ基が好ましい。 Examples of the alkoxy group in R 1 of the formula (I) include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like, an allyloxy group containing a double bond, etc., and an alkoxy substitution such as a methoxyethoxy group and a methoxyethoxyethoxy group. An alkoxy group etc. are mentioned. The hydrogen element in these alkoxy groups may be substituted with a halogen element, and is preferably substituted with fluorine. Among these, a methoxy group, an ethoxy group, a trifluoroethoxy group, and a propoxy group are preferable in terms of excellent flame retardancy and low viscosity.
式(I)のＲlにおけるアリールオキシ基としては、フェノキシ基、メチルフェノキシ基、メトキシフェノキシ基等が挙げられる。これらアリールオキシ基中の水素元素は、ハロゲン元素で置換されていてもよく、フッ素で置換されていることが好ましい。これらの中でも、難燃性に優れる点で、フェノキシ基、フルオロフェノキシ基が好ましい。 Examples of the aryloxy group for R 1 in formula (I) include a phenoxy group, a methylphenoxy group, and a methoxyphenoxy group. The hydrogen element in these aryloxy groups may be substituted with a halogen element, and is preferably substituted with fluorine. Among these, a phenoxy group and a fluorophenoxy group are preferable in terms of excellent flame retardancy.
上記一般式(I)の２つのＲ1は、同一でも異なってもよい。また、２つのＲ1は連結していてもよく、この場合、２つのＲ1は、互いに結合して、アルキレンジオキシ基、アリーレンジオキシ基又はオキシアルキレンアリーレンオキシ基を形成し、かかる二価の基としては、エチレンジオキシ基、プロピレンジオキシ基等が挙げられる。特に、上記一般式(I)のフルオロリン酸エステル化合物の中でも、２つのＲ1のうち１つがフッ素であり、他の１つがアルコキシ基又はアリールオキシ基であるジフルオロリン酸エステルが、低粘度、難燃性の点で最も好ましい。 Two R 1 in the general formula (I) may be the same or different. In addition, two R 1 may be linked, and in this case, the two R 1 are bonded to each other to form an alkylenedioxy group, an aryleneoxy group, or an oxyalkylenearyleneoxy group. Examples of the group include an ethylenedioxy group and a propylenedioxy group. In particular, among the fluorophosphate ester compounds of the above general formula (I), a difluorophosphate ester in which one of two R 1 is fluorine and the other is an alkoxy group or an aryloxy group has a low viscosity, Most preferable in terms of flame retardancy.
式(I)のフルオロリン酸エステル化合物の具体例としては、フルオロリン酸ジメチル、フルオロリン酸ジエチル、フルオロリン酸ビストリフルオロエチル、フルオロリン酸エチレン、フルオロリン酸プロピレン、フルオロリン酸ジプロピル、フルオロリン酸ジブチル、フルオロリン酸ジフェニル、フルオロリン酸ジフルオロフェニル、ジフルオロリン酸メチル、ジフルオロリン酸エチル、ジフルオロリン酸トリフルオロエチル、ジフルオロリン酸プロピル、ジフルオロリン酸ブチル、ジフルオロリン酸シクロへキシル、ジフルオロリン酸メトキシエチル、ジフルオロリン酸メトキシエトキシエチル、ジフルオロリン酸フェニル、ジフルオロリン酸フルオロフェニル等が挙げられる。このらの中でも、ジフルオロリン酸メチル、ジフルオロリン酸エチル、ジフルオロリン酸トリフルオロエチル、ジフルオロリン酸プロピル、ジフルオロリン酸フェニルがより好ましい。これら式(I)のフルオロリン酸エステル化合物は、１種単独で用いてもよいし、２種以上を混合して用いてもよい。 Specific examples of the fluorophosphate ester compound of the formula (I) include dimethyl fluorophosphate, diethyl fluorophosphate, bistrifluoroethyl fluorophosphate, ethylene fluorophosphate, propylene fluorophosphate, dipropyl fluorophosphate, fluorophosphate Dibutyl acid, diphenyl fluorophosphate, difluorophenyl fluorophosphate, methyl difluorophosphate, ethyl difluorophosphate, trifluoroethyl difluorophosphate, propyl difluorophosphate, butyl difluorophosphate, cyclohexyl difluorophosphate, difluorophosphorus Examples include methoxyethyl acid, methoxyethoxyethyl difluorophosphate, phenyl difluorophosphate, and fluorophenyl difluorophosphate. Among these, methyl difluorophosphate, ethyl difluorophosphate, trifluoroethyl difluorophosphate, propyl difluorophosphate, and phenyl difluorophosphate are more preferable. These fluorophosphate ester compounds of the formula (I) may be used alone or in combination of two or more.
上記式(I)のフルオロリン酸エステル化合物の含有量は、本発明の目的から、非水電解液中20体積％以上であることを要する。式(I)のフルオロリン酸エステル化合物の含有量が20体積％未満でも難燃性の点では満足できるが、本発明の目的である高い導電性すなわち負荷特性の改良の効果が低い。一方、式(I)のフルオロリン酸エステル化合物を電解液中20体積％以上用いることで、電解液が不燃性を示す上、負荷特性の改良効果が顕著に現れる。 For the purpose of the present invention, the content of the fluorophosphate ester compound of the above formula (I) is required to be 20% by volume or more in the nonaqueous electrolytic solution. Even if the content of the fluorophosphate ester compound of the formula (I) is less than 20% by volume, it is satisfactory in terms of flame retardancy, but the effect of improving the high conductivity, that is, the load characteristics, which is the object of the present invention, is low. On the other hand, when the fluorophosphate ester compound of the formula (I) is used in an amount of 20% by volume or more in the electrolytic solution, the electrolytic solution exhibits nonflammability, and the effect of improving load characteristics is remarkably exhibited.
本発明のリチウム二次電池用非水電解液には、上記式(I)のフルオロリン酸エステル化合物と併用して上記一般式(II)で表される不飽和環状エステル化合物を用いることが好ましく、この場合、さらに優れた負荷特性を得ることができる。理由は必ずしも明らかではないが、式(I)のフルオロリン酸エステル化合物と式(II)の不飽和環状エステル化合物とを用いることにより、よりリチウムイオン導電性の高い保護膜が電極表面に形成されるものと考えられる。なお、式(II)において、Ｒ2は、それぞれ独立して水素、フッ素又は炭素数１〜２のアルキル基であり、該アルキル基中の水素元素は、フッ素で置換されていてもよい。 In the non-aqueous electrolyte for a lithium secondary battery of the present invention, it is preferable to use an unsaturated cyclic ester compound represented by the above general formula (II) in combination with the fluorophosphate ester compound of the above formula (I). In this case, further excellent load characteristics can be obtained. The reason is not necessarily clear, but by using the fluorophosphate ester compound of formula (I) and the unsaturated cyclic ester compound of formula (II), a protective film with higher lithium ion conductivity is formed on the electrode surface. It is thought that. In formula (II), each R 2 is independently hydrogen, fluorine or an alkyl group having 1 to 2 carbon atoms, and the hydrogen element in the alkyl group may be substituted with fluorine.
式(II)の不飽和環状エステル化合物の具体例としては、ビニレンカーボネート、カテコールカーボネート、４-フルオロビニレンカーボネート、４,５-ジフルオロビニレンカーボネート、４-メチルビニレンカーボネート、４,５-ジメチルビニレンカーボネート、４-フルオロメチルビニレンカーボネート、４-ジフルオロメチルビニレンカーボネート、４-トリフルオロメチルビニレンカーボネート、４-エチルビニレンカーボネート、４,５-ジエチルビニレンカーボネート、４-フルオロエチルビニレンカーボネート、４-ジフルオロエチルビニレンカーボネート、４-トリフルオロエチルビニレンカーボネート、４,５-ビストリフルオロメチルビニレンカーボネート等が挙げられる。これらの中でも、ビニレンカーボネート、４-フルオロビニレンカーボネートが好ましい。これら不飽和環状エステル化合物は、１種単独で使用してもよく、２種以上を混合して使用してもよい。 Specific examples of the unsaturated cyclic ester compound of the formula (II) include vinylene carbonate, catechol carbonate, 4-fluoro vinylene carbonate, 4,5-difluoro vinylene carbonate, 4-methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, 4-fluoromethyl vinylene carbonate, 4-difluoromethyl vinylene carbonate, 4-trifluoromethyl vinylene carbonate, 4-ethyl vinylene carbonate, 4,5-diethyl vinylene carbonate, 4-fluoroethyl vinylene carbonate, 4-difluoroethyl vinylene carbonate, Examples include 4-trifluoroethyl vinylene carbonate, 4,5-bistrifluoromethyl vinylene carbonate, and the like. Among these, vinylene carbonate and 4-fluoro vinylene carbonate are preferable. These unsaturated cyclic ester compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.
上記不飽和環状エステル化合物の含有量は、非水電解液全体の0.1〜10質量％の範囲が好ましく、電池性能のバランスの観点から、0.5〜8質量％の範囲が更に好ましい。 The content of the unsaturated cyclic ester compound is preferably in the range of 0.1 to 10% by mass of the whole non-aqueous electrolyte, and more preferably in the range of 0.5 to 8% by mass from the viewpoint of balance of battery performance.
本発明のリチウム二次電池用非水電解液を調製するにあたり、上記化合物以外に使用する非水溶媒としては、従来より電池用の非水電解液に使用されている種々の非プロトン性溶媒を使用することができる。該非プロトン性溶媒として具体的には、ジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、ジフェニルカーボネート、エチルメチルカーボネート（ＥＭＣ）、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）等の炭酸エステル類、１,２-ジメトキシエタン（ＤＭＥ）、テトラヒドロフラン（ＴＨＦ）、ジエチルエーテル（ＤＥＥ）等のエーテル類、γ-ブチロラクトン（ＧＢＬ）、γ-バレロラクトン、メチルフォルメート（ＭＦ）等のカルボン酸エステル類、アセトニトリル等のニトリル類、ジメチルホルムアミド等のアミド類、ジメチルスルホキシド等のスルホン類、Ｐ＝Ｎ結合を有するホスファゼン化合物等が挙げられる。これら非プロトン性溶媒の中でも、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）が好ましい。これら非プロトン性溶媒は、１種単独で使用してもよく、２種以上を混合して用いてもよい。 In preparing the non-aqueous electrolyte for lithium secondary batteries of the present invention, as the non-aqueous solvent used in addition to the above compounds, various aprotic solvents conventionally used in non-aqueous electrolytes for batteries are used. Can be used. Specific examples of the aprotic solvent include carbonate esters such as dimethyl carbonate (DMC), diethyl carbonate (DEC), diphenyl carbonate, ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC). , 2-dimethoxyethane (DME), tetrahydrofuran (THF), diethyl ether (DEE) and other ethers, γ-butyrolactone (GBL), γ-valerolactone, carboxylic acid esters such as methyl formate (MF), acetonitrile And nitriles such as dimethylformamide, sulfones such as dimethyl sulfoxide, and phosphazene compounds having a P = N bond. Among these aprotic solvents, ethylene carbonate (EC) and propylene carbonate (PC) are preferable. These aprotic solvents may be used individually by 1 type, and 2 or more types may be mixed and used for them.
また、本発明のリチウム二次電池用非水電解液には、本発明の目的を損なわない範囲で、デンドライトの成長の抑制等に効果があるとされるチオフェンやフランのような不飽和ヘテロ環状化合物、ナフタレンやビフェニル誘導体のような芳香族炭化水素等を添加してもよい。また、リチウム二次電池の形成に際して本発明の電解液は、そのまま用いることも可能であるが、例えば適当なポリマーや多孔性支持体、あるいはゲル状物質に含浸させるなどして保持させて用いることもできる。 In addition, the non-aqueous electrolyte for a lithium secondary battery of the present invention has an unsaturated heterocyclic ring such as thiophene and furan, which is said to be effective in suppressing the growth of dendrites, as long as the object of the present invention is not impaired. You may add a compound, aromatic hydrocarbons, such as a naphthalene and a biphenyl derivative. In addition, the electrolyte solution of the present invention can be used as it is in the formation of a lithium secondary battery, but it can be used by being impregnated with, for example, an appropriate polymer, a porous support, or a gel material. You can also.
本発明のリチウム二次電池用非水電解液に用いる支持塩としては、リチウムイオンのイオン源となる支持塩が好ましい。該支持塩としては、特に制限はないが、例えば、ＬｉＣｌＯ4、ＬｉＢＦ4、ＬｉＰＦ6、ＬｉＣＦ3ＳＯ3、ＬｉＡｓＦ6、ＬｉＣ4Ｆ9ＳＯ3、Ｌｉ(ＣＦ3ＳＯ2)2Ｎ及びＬｉ(Ｃ2Ｆ5ＳＯ2)2Ｎ等のリチウム塩が好適に挙げられる。これらの中でも、不燃性に優れる点で、ＬｉＰＦ6が更に好ましい。これら支持塩は、１種単独で使用してもよく、２種以上を組み合わせて用いてもよい。 As the supporting salt used in the non-aqueous electrolyte for a lithium secondary battery of the present invention, a supporting salt serving as an ion source of lithium ions is preferable. The supporting salt is not particularly limited, and for example, LiClO 4 , LiBF 4 , LiPF 6 , LiCF 3 SO 3 , LiAsF 6 , LiC 4 F 9 SO 3 , Li (CF 3 SO 2 ) 2 N and Li ( Preferable examples include lithium salts such as C 2 F 5 SO 2 ) 2 N. Among these, LiPF 6 is more preferable in terms of excellent nonflammability. These supporting salts may be used alone or in combination of two or more.
上記非水電解液中の支持塩の濃度としては、0.2〜1.5mol/L(Ｍ)が好ましく、0.5〜1mol/L(Ｍ)が更に好ましい。支持塩の濃度が0.2mol/L未満では、電解液の導電性を充分に確保することができず、電池の放電特性及び充電特性に支障をきたすことがあり、1.5mol/Lを超えると、電解液の粘度が上昇し、リチウムイオンの移動度を充分に確保できないため、前述と同様に電解液の導電性を充分に確保できず、電池の放電特性及び充電特性に支障をきたすことがある。 The concentration of the supporting salt in the non-aqueous electrolyte is preferably 0.2 to 1.5 mol / L (M), more preferably 0.5 to 1 mol / L (M). If the concentration of the supporting salt is less than 0.2 mol / L, the conductivity of the electrolyte cannot be sufficiently ensured, and the discharge characteristics and charging characteristics of the battery may be hindered. Since the viscosity of the electrolytic solution increases and the mobility of lithium ions cannot be ensured sufficiently, the conductivity of the electrolytic solution cannot be sufficiently ensured in the same manner as described above, which may hinder battery discharge characteristics and charge characteristics. .
＜リチウム二次電池＞
次に、本発明のリチウム二次電池を詳細に説明する。本発明のリチウム二次電池は、上述のリチウム二次電池用非水電解液と、正極と、リチウム又はその合金を用いた負極とを備え、必要に応じて、セパレーター等の電池の技術分野で通常使用されている他の部材を備える。
<Lithium secondary battery>
Next, the lithium secondary battery of the present invention will be described in detail. The lithium secondary battery of the present invention comprises the above-described non-aqueous electrolyte for a lithium secondary battery, a positive electrode, and a negative electrode using lithium or an alloy thereof, and, if necessary, in the technical field of a battery such as a separator. Other members that are normally used are provided.
本発明のリチウム二次電池の負極には、リチウムや、リチウムとＡｌ、Ｉｎ、Ｓｎ、Ｓｉ、Ｐｂ又はＺｎ等との合金を用いることができる。これら負極材料は、１種単独で使用してもよく、２種以上を混合して使用してもよい。 For the negative electrode of the lithium secondary battery of the present invention, lithium or an alloy of lithium and Al, In, Sn, Si, Pb, Zn, or the like can be used. These negative electrode materials may be used individually by 1 type, and 2 or more types may be mixed and used for them.
本発明のリチウム二次電池の正極活物質としては、特に限定は無いが、Ｖ2Ｏ5、Ｖ6Ｏ13、ＭｎＯ2、ＭｎＯ3等の金属酸化物、ＬｉＣｏＯ2、ＬｉＮｉＯ2、ＬｉＭｎ2Ｏ4、ＬｉＦｅＯ2及びＬｉＦｅＰＯ4等のリチウム含有複合酸化物、ＴｉＳ2、ＭｏＳ2等の金属硫化物、ポリアニリン等の導電性ポリマー等が好適に挙げられる。上記リチウム含有複合酸化物は、Ｆｅ、Ｍｎ、Ｃｏ及びＮｉからなる群から選択される２種又は３種の遷移金属を含む複合酸化物であってもよく、この場合、該複合酸化物は、ＬｉＦｅxＣｏyＮｉ(1-x-y)Ｏ2［式中、０≦ｘ＜１、０≦ｙ＜１、０＜ｘ＋ｙ≦１］、或いはＬｉＭｎxＦｅyＯ2-x-y等で表される。これらの中でも、高容量で安全性が高く、更には電解液の濡れ性に優れる点で、ＬｉＣｏＯ2、ＬｉＮｉＯ2、ＬｉＭｎ2Ｏ4が特に好適である。これら正極活物質は、１種単独で使用してもよく、２種以上を併用してもよい。 The positive electrode active material of the lithium secondary battery of the present invention is not particularly limited, but metal oxides such as V 2 O 5 , V 6 O 13 , MnO 2 , MnO 3 , LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , Li-containing composite oxides such as LiFeO 2 and LiFePO 4 , metal sulfides such as TiS 2 and MoS 2 , and conductive polymers such as polyaniline are preferable. The lithium-containing composite oxide may be a composite oxide containing two or three transition metals selected from the group consisting of Fe, Mn, Co, and Ni. In this case, the composite oxide includes: LiFe x Co y Ni [wherein, 0 ≦ x <1,0 ≦ y <1,0 <x + y ≦ 1] (1-xy) O 2, or represented by LiMn x Fe y O 2-xy like. Among these, LiCoO 2 , LiNiO 2 , and LiMn 2 O 4 are particularly preferable in terms of high capacity, high safety, and excellent electrolyte wettability. These positive electrode active materials may be used individually by 1 type, and may use 2 or more types together.
上記正極には、必要に応じて導電剤、結着剤を混合することができ、導電剤としてはアセチレンブラック等が挙げられ、結着剤としてはポリフッ化ビニリデン（ＰＶＤＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、スチレン・ブタジエンゴム（ＳＢＲ）、カルボキシメチルセルロース（ＣＭＣ）等が挙げられる。これらの添加剤は、従来と同様の配合割合で用いることができる。 The positive electrode can be mixed with a conductive agent and a binder as necessary. Examples of the conductive agent include acetylene black, and the binder includes polyvinylidene fluoride (PVDF), polytetrafluoroethylene ( PTFE), styrene / butadiene rubber (SBR), carboxymethyl cellulose (CMC), and the like. These additives can be used at a blending ratio similar to the conventional one.
本発明のリチウム二次電池に使用できる他の部材としては、リチウム二次電池において、正負極間に、両極の接触による電流の短絡を防止する役割で介在させるセパレーターが挙げられる。セパレーターの材質としては、両極の接触を確実に防止し得、且つ電解液を通したり含んだりできる材料、例えば、ポリテトラフルオロエチレン、ポリプロピレン、ポリエチレン、セルロース系、ポリブチレンテレフタレート、ポリエチレンテレフタレート等の合成樹脂製の不織布、薄層フィルム等が好適に挙げられる。これらは、単体でも、混合物でも、共重合体でもよい。これらの中でも、厚さ20〜50μm程度のポリプロピレン又はポリエチレン製の微孔性フィルム、セルロース系、ポリブチレンテレフタレート、ポリエチレンテレフタレート等のフィルムが特に好適である。本発明では、上述のセパレーターの他にも、通常電池に使用されている公知の各部材が好適に使用できる。 Other members that can be used in the lithium secondary battery of the present invention include a separator that is interposed between positive and negative electrodes in order to prevent a short circuit of current due to contact between both electrodes in the lithium secondary battery. As the material of the separator, it is possible to reliably prevent contact between the two electrodes and to allow the electrolyte to pass through or to contain, for example, synthesis of polytetrafluoroethylene, polypropylene, polyethylene, cellulose, polybutylene terephthalate, polyethylene terephthalate, etc. Preferred examples include resin non-woven fabrics and thin layer films. These may be a single substance, a mixture or a copolymer. Of these, polypropylene or polyethylene microporous films having a thickness of about 20 to 50 μm, cellulose-based films, polybutylene terephthalate, polyethylene terephthalate, and the like are particularly suitable. In the present invention, in addition to the separators described above, known members that are normally used in batteries can be suitably used.
以上に説明した本発明のリチウム二次電池の形態としては、特に制限はなく、コインタイブ、ボタンタイプ、ペーパータイプ、角型又はスパイラル構造の円筒型電池等、種々の公知の形態が好適に挙げられる。ボタンタイプの場合は、シート状の正極及び負極を作製し、該正極及び負極でセパレーターを挟む等して、リチウム二次電池を作製することができる。また、スパイラル構造の場合は、例えば、シート状の正極を作製して集電体を挟み、これにシート状の負極を重ね合わせて巻き上げる等して、リチウム二次電池を作製することができる。 The form of the lithium secondary battery of the present invention described above is not particularly limited, and various known forms such as a coin type, a button type, a paper type, a square type or a spiral type cylindrical battery are preferably exemplified. . In the case of the button type, a lithium secondary battery can be produced by preparing a sheet-like positive electrode and negative electrode and sandwiching a separator between the positive electrode and the negative electrode. In the case of the spiral structure, for example, a lithium secondary battery can be manufactured by preparing a sheet-like positive electrode, sandwiching a current collector, and stacking and winding up the sheet-like negative electrode on the current collector.
以下に、実施例を挙げて本発明を更に詳しく説明するが、本発明は下記の実施例に何ら限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
（実施例１）
ジフルオロリン酸メチル 20体積％、エチレンカーボネート 40体積％、メチルエチルカーボネート 40体積％からなる混合溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて非水電解液を調製し、導電率計を用いて25℃における導電率を測定した。また、難燃性評価を下記（１）の方法で実施した。結果を表１に示す。
Example 1
A non-aqueous electrolyte was prepared by dissolving LiPF 6 in a mixed solvent of 20% by volume of methyl difluorophosphate, 40% by volume of ethylene carbonate, and 40% by volume of methyl ethyl carbonate to a concentration of 1 mol / L. The conductivity at 25 ° C. was measured. Moreover, flame retardance evaluation was implemented by the method of the following (1). The results are shown in Table 1.
（１）難燃性の評価
ＵＬ（アンダーライティングラボラトリー）規格のＵＬ９４ＨＢ法をアレンジした方法で、大気環境下において着火した炎の燃焼長及び燃焼時間を測定・評価した。具体的には、ＵＬ試験基準に基づき、127mm×12.7mmのＳｉＯ2シートに上記電解液1.0mLを染み込ませて試験片を作製して評価を行った。以下に不燃性・難燃性・自己消火性・燃焼性の評価基準を示す。
＜不燃性の評価＞試験炎を点火しても全く着火しなかった場合（燃焼長：0mm）を不燃性ありと評価した。
＜難燃性の評価＞着火した炎が、装置の25mmラインまで到達せず且つ網からの落下物にも着火が認められなかった場合を難燃性ありと評価した。
＜自己消火性の評価＞着火した炎が25〜100mmラインで消火し且つ網からの落下物にも着火が認められなかった場合を自己消火性ありと評価した。
＜燃焼性の評価＞着火した炎が、100mmラインを超えた場合を燃焼性と評価した。
(1) Flame Retardancy Evaluation The combustion length and combustion time of a flame ignited in an atmospheric environment were measured and evaluated by a method in which the UL94HB method of UL (Underwriting Laboratory) standard was arranged. Specifically, based on the UL test standard, a test piece was prepared by impregnating a 127 mm × 12.7 mm SiO 2 sheet with the above electrolytic solution 1.0 mL, and evaluated. The evaluation criteria for nonflammability, flame retardancy, self-extinguishing properties, and flammability are shown below.
<Evaluation of Nonflammability> A case where the test flame did not ignite at all (ignition length: 0 mm) was evaluated as nonflammable.
<Evaluation of Flame Retardancy> The case where the ignited flame did not reach the 25 mm line of the apparatus and the fallen object from the net was not ignited was evaluated as flame retardant.
<Evaluation of self-extinguishing property> When the ignited flame was extinguished in the 25 to 100 mm line and no ignition was observed on the falling object from the net, it was evaluated as having self-extinguishing property.
<Evaluation of combustibility> The case where the ignited flame exceeded the 100 mm line was evaluated as combustible.
次に、正極活物質としでリチウムマンガン複合酸化物（ＬｉＭｎ2Ｏ4）を用い、該酸化物と、導電剤であるアセチレンブラックと、結着剤であるフッ素樹脂とを、質量比で90：5：5で混合し、これをＮ-メチルピロリドンに分散させてスラリーとしたものを、正極集電体としてのアルミニウム箔に塗布・乾燥した後、直径12.5mmの円板状に打ち抜いて、正極を作製した。一方、負極としては、直径12.5mm、厚さ1.0mmのリチウム金属シートを用いた。次いで、正極端子を兼ねたステンレスケース内に、正極と負極とを、電解液を含浸したセパレーター（微孔性フィルム：ポリプロピレン製）を介して重ねて収容し、ポリプロピレン製ガスケットを介して負極端子を兼ねるステンレス製封口板で密封して、直径20mm、厚さ1.6mmのコイン型電池（リチウム二次電池）を作製した。 Next, lithium manganese composite oxide (LiMn 2 O 4 ) is used as the positive electrode active material, and the oxide, the acetylene black as the conductive agent, and the fluororesin as the binder in a mass ratio of 90: After mixing 5: 5 and dispersing this in N-methylpyrrolidone, the slurry was applied to an aluminum foil as the positive electrode current collector and dried, then punched into a disk shape with a diameter of 12.5 mm. Was made. On the other hand, a lithium metal sheet having a diameter of 12.5 mm and a thickness of 1.0 mm was used as the negative electrode. Next, the positive electrode and the negative electrode are stacked and accommodated in a stainless steel case that also serves as a positive electrode terminal via a separator (microporous film: made of polypropylene) impregnated with an electrolytic solution, and the negative electrode terminal is inserted through a polypropylene gasket. A coin-type battery (lithium secondary battery) having a diameter of 20 mm and a thickness of 1.6 mm was produced by sealing with a stainless steel sealing plate that also serves as a battery.
（２）コイン型電池による充放電試験
上記のようにして作製したコイン型電池を用い、20℃の環境下で、4.2〜3.0Vの電圧範囲で、0.2mA/cm2の電流密度による充放電サイクルを２回繰り返し、この時の放電容量を既知の正極質量で除することにより初期放電容量（mAh/g）を求めた。その後、2.0mA/cm2の電流密度に変えて、さらに充放電サイクルを２回行い、その放電容量の平均値から次式：
負荷特性（％）＝（2.0mA/cm2の電流密度による放電容量の平均値）／（0.2mA/cm2の電流密度による放電容量の平均値）×100
を用いて負荷特性（％）を算出した。結果を表１に示す。
(2) Charging / discharging test using a coin-type battery Charging / discharging at a current density of 0.2 mA / cm 2 in a voltage range of 4.2 to 3.0 V in a 20 ° C environment using the coin-type battery produced as described above. The cycle was repeated twice, and the initial discharge capacity (mAh / g) was determined by dividing the discharge capacity at this time by the known positive electrode mass. Thereafter, the current density was changed to 2.0 mA / cm 2 and the charge / discharge cycle was further performed twice. From the average value of the discharge capacity, the following formula:
Load characteristics (%) = (Average discharge capacity at a current density of 2.0 mA / cm 2 ) / (Average discharge capacity at a current density of 0.2 mA / cm 2 ) × 100
Was used to calculate the load characteristics (%). The results are shown in Table 1.
（実施例２）
ジフルオロリン酸エチル 50体積％と、エチレンカーボネート 25体積％と、メチルエチルカーボネート 25体積％とからなる混合溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて、更に４-フルオロビニレンカーボネート 3質量％を添加して非水電解液を調製し、実施例１と同様にして得られた非水電解液の導電率及び難燃性を評価した。また、実施例１と同様にしてリチウム二次電池を作製し、充放電試験における初期放電容量及び負荷特性を測定、評価した。結果を表１に示す。
(Example 2)
LiPF 6 is dissolved in a mixed solvent consisting of 50% by volume of ethyl difluorophosphate, 25% by volume of ethylene carbonate, and 25% by volume of methyl ethyl carbonate so as to be 1 mol / L, and further 4 mass of 4-fluorovinylene carbonate. % Was added to prepare a nonaqueous electrolytic solution, and the electrical conductivity and flame retardancy of the nonaqueous electrolytic solution obtained in the same manner as in Example 1 were evaluated. Further, a lithium secondary battery was produced in the same manner as in Example 1, and the initial discharge capacity and load characteristics in the charge / discharge test were measured and evaluated. The results are shown in Table 1.
（実施例３）
ジフルオロリン酸プロピル 100体積％からなる溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて、更にビニレンカーボネート 3質量％を添加して非水電解液を調製し、実施例１と同様にして得られた非水電解液の導電率及び難燃性を評価した。また、実施例１と同様にしてリチウム二次電池を作製し、充放電試験における初期放電容量及び負荷特性を測定、評価した。結果を表１に示す。
(Example 3)
LiPF 6 was dissolved in a solvent composed of 100% by volume of propyl difluorophosphate so as to be 1 mol / L, and 3% by mass of vinylene carbonate was further added to prepare a nonaqueous electrolytic solution. The electrical conductivity and flame retardancy of the obtained nonaqueous electrolytic solution were evaluated. Further, a lithium secondary battery was produced in the same manner as in Example 1, and the initial discharge capacity and load characteristics in the charge / discharge test were measured and evaluated. The results are shown in Table 1.
（比較例１）
エチレンカーボネート 50体積％と、メチルエチルカーボネート 50体積％とからなる混合溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて非水電解液を調製し、実施例１と同様にして得られた非水電解液の導電率及び難燃性を評価した。また、実施例１と同様にしてリチウム二次電池を作製し、充放電試験における初期放電容量及び負荷特性を測定、評価した。結果を表１に示す。
(Comparative Example 1)
A non-aqueous electrolyte was prepared by dissolving LiPF 6 in a mixed solvent consisting of 50% by volume of ethylene carbonate and 50% by volume of methyl ethyl carbonate so as to be 1 mol / L, and was obtained in the same manner as in Example 1. The electrical conductivity and flame retardancy of the non-aqueous electrolyte were evaluated. Further, a lithium secondary battery was produced in the same manner as in Example 1, and the initial discharge capacity and load characteristics in the charge / discharge test were measured and evaluated. The results are shown in Table 1.
（比較例２）
リン酸トリメチル 20体積％と、エチレンカーボネート 40体積％と、エチルメチルカーボネート 40体積％とからなる混合溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて、更にビニレンカーボネート 3質量％を添加して非水電解液を調製し、実施例１と同様にして得られた非水電解液の導電率及び難燃性を評価した。また、実施例１と同様にしてリチウム二次電池を作製し、充放電試験における初期放電容量及び負荷特性を測定、評価した。結果を表１に示す。
(Comparative Example 2)
LiPF 6 was dissolved in a mixed solvent consisting of 20% by volume of trimethyl phosphate, 40% by volume of ethylene carbonate, and 40% by volume of ethyl methyl carbonate so as to be 1 mol / L, and 3% by mass of vinylene carbonate was further added. A nonaqueous electrolytic solution was prepared, and the electrical conductivity and flame retardancy of the nonaqueous electrolytic solution obtained in the same manner as Example 1 were evaluated. Further, a lithium secondary battery was produced in the same manner as in Example 1, and the initial discharge capacity and load characteristics in the charge / discharge test were measured and evaluated. The results are shown in Table 1.
（比較例３）
リン酸トリエチル 50体積％と、エチレンカーボネート 25体積％と、エチルメチルカーボネート 25体積％とからなる混合溶媒にＬｉＰＦ6を1mol/Lになるように溶解させて、更にビニレンカーボネート 3質量％を添加して非水電解液を調製し、実施例１と同様にして得られた非水電解液の導電率及び難燃性を評価した。また、実施例１と同様にしてリチウム二次電池を作製し、充放電試験における初期放電容量及び負荷特性を測定、評価した。結果を表１に示す。
(Comparative Example 3)
LiPF 6 is dissolved in a mixed solvent consisting of 50% by volume of triethyl phosphate, 25% by volume of ethylene carbonate, and 25% by volume of ethyl methyl carbonate so as to be 1 mol / L, and 3% by mass of vinylene carbonate is further added. A nonaqueous electrolytic solution was prepared, and the electrical conductivity and flame retardancy of the nonaqueous electrolytic solution obtained in the same manner as Example 1 were evaluated. Further, a lithium secondary battery was produced in the same manner as in Example 1, and the initial discharge capacity and load characteristics in the charge / discharge test were measured and evaluated. The results are shown in Table 1.
表１の実施例１〜３に示すように、式(I)、または式(I)と式(II)の化合物を含む非水電解液が難燃性又は不燃性を示すと共に、高い導電率を示し、また、それを用いた電池が負荷特性に優れていることがわかる。このように本発明のリチウム二次電池用非水電解液は、高い難燃性と導電率を有しており、また、該非水電解液をリチウム二次電池に用いることで、安全性及び負荷特性に優れたリチウム二次電池が得られることが確認された。 As shown in Examples 1 to 3 of Table 1, the nonaqueous electrolyte containing the compound of formula (I) or formula (I) and formula (II) exhibits flame retardancy or nonflammability, and has high conductivity. In addition, it can be seen that a battery using the same has excellent load characteristics. Thus, the non-aqueous electrolyte for lithium secondary batteries of the present invention has high flame retardancy and conductivity, and safety and load are improved by using the non-aqueous electrolyte for lithium secondary batteries. It was confirmed that a lithium secondary battery having excellent characteristics can be obtained.
一方、表１の比較例２、３に示すように、通常のリン酸トリエステルを添加した非水電解液は、添加量が増すにつれて難燃性が向上するものの、導電率が低下する上、リン酸トリエステルの還元分解により、電池の初期放電容量及び負荷特性が低下してしまうことがわかる。 On the other hand, as shown in Comparative Examples 2 and 3 in Table 1, the non-aqueous electrolyte to which ordinary phosphoric acid triester is added improves the flame retardancy as the amount added increases, but the conductivity decreases. It can be seen that the initial discharge capacity and load characteristics of the battery are reduced by reductive decomposition of the phosphoric acid triester.
以上の結果から、式(I)で表されるフルオロリン酸エステル化合物を含有することを特徴とする非水電解液を用いることにより、高い難燃性と電池性能とを両立させたリチウム二次電池を提供できることが分る。 From the above results, by using a non-aqueous electrolyte characterized by containing a fluorophosphate ester compound represented by formula (I), a lithium secondary that achieves both high flame retardancy and battery performance It turns out that a battery can be provided.
Claims (5)
前記非水電解液が下記一般式(I)：
［式中、Ｒ1は、それぞれ独立してフッ素、アルコキシ基又はアリールオキシ基であり、２つのＲlのうち少なくとも一つはアルコキシ基又はアリールオキシ基であり、但し、２つのＲ1は互いに結合して環を形成してもよい］で表されるフルオロリン酸エステル化合物を20体積％以上含むことを特徴とするリチウム二次電池用非水電解液。 In a non-aqueous electrolyte for a lithium secondary battery containing a non-aqueous solvent and a supporting salt and using lithium or an alloy thereof as a negative electrode,
The non-aqueous electrolyte is represented by the following general formula (I):
[Wherein R 1 is independently a fluorine, alkoxy group or aryloxy group, and at least one of the two R 1 is an alkoxy group or aryloxy group, provided that two R 1 are A nonaqueous electrolytic solution for a lithium secondary battery, comprising 20% by volume or more of a fluorophosphate ester compound represented by the formula:
［式中、Ｒ2は、それぞれ独立して水素、フッ素又は炭素数１〜２のアルキル基である］で表される不飽和環状エステル化合物を含むことを特徴とする請求項１又は２に記載のリチウム二次電池用非水電解液。 The non-aqueous electrolyte further has the following general formula (II):
3. An unsaturated cyclic ester compound represented by the formula: wherein R 2 is each independently hydrogen, fluorine or an alkyl group having 1 to 2 carbon atoms. 4. Non-aqueous electrolyte for lithium secondary batteries.
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| Application Number | Priority Date | Filing Date | Title |
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| JP2005108691A JP2006286570A (en) | 2005-04-05 | 2005-04-05 | Nonaqueous electrolyte for lithium secondary battery and lithium secondary battery having it |
| US11/910,022 US20080254361A1 (en) | 2005-03-31 | 2006-03-20 | Non-Aqueous Electrolyte for Battery and Non-Aqueous Electrolyte Secondary Battery Comprising the Same |
| PCT/JP2006/305541 WO2006109443A1 (en) | 2005-03-31 | 2006-03-20 | Nonaqueous electrolyte solution for battery and nonaqueous electrolyte secondary battery comprising same |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009142251A1 (en) * | 2008-05-19 | 2009-11-26 | 日本電気株式会社 | Secondary battery |
| KR101181835B1 (en) * | 2010-06-07 | 2012-09-11 | 솔브레인 주식회사 | Electrolyte for lithium secondary battery including additives, and lithium secondary battery including the same |
| JP2014160608A (en) * | 2013-02-20 | 2014-09-04 | Shin Kobe Electric Mach Co Ltd | Lithium ion battery |
| US10287263B2 (en) | 2014-11-21 | 2019-05-14 | Daikin Industries, Ltd. | Fluorinated unsaturated cyclic carbonate and process for producing same |
| CN115799643A (en) * | 2023-01-18 | 2023-03-14 | 如鲲(江苏)新材料科技有限公司 | Nonaqueous electrolyte solution, lithium ion battery, battery module, battery pack, and electric device |
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2005
- 2005-04-05 JP JP2005108691A patent/JP2006286570A/en not_active Withdrawn
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009142251A1 (en) * | 2008-05-19 | 2009-11-26 | 日本電気株式会社 | Secondary battery |
| JPWO2009142251A1 (en) * | 2008-05-19 | 2011-09-29 | 日本電気株式会社 | Secondary battery |
| JP5645260B2 (en) * | 2008-05-19 | 2014-12-24 | 日本電気株式会社 | Secondary battery |
| KR101181835B1 (en) * | 2010-06-07 | 2012-09-11 | 솔브레인 주식회사 | Electrolyte for lithium secondary battery including additives, and lithium secondary battery including the same |
| US8388856B2 (en) | 2010-06-07 | 2013-03-05 | Samsung Sdi Co., Ltd. | Electrolyte for rechargeable lithium battery including additives, and rechargeable lithium battery including the same |
| JP2014160608A (en) * | 2013-02-20 | 2014-09-04 | Shin Kobe Electric Mach Co Ltd | Lithium ion battery |
| US10287263B2 (en) | 2014-11-21 | 2019-05-14 | Daikin Industries, Ltd. | Fluorinated unsaturated cyclic carbonate and process for producing same |
| EP3205649A4 (en) * | 2014-11-21 | 2019-07-31 | Daikin Industries, Ltd. | Novel fluorinated unsaturated cyclic carbonate and process for producing same |
| US10464916B2 (en) | 2014-11-21 | 2019-11-05 | Daikin Industries, Ltd. | Fluorinated unsaturated cyclic carbonate and process for producing the same |
| EP3667804A1 (en) | 2014-11-21 | 2020-06-17 | Daikin Industries, Limited | Electrolyte solution containing unsaturated cyclic carbonates, electrochemical device and lithium-ion secondary battery comprising the same |
| EP3750884A1 (en) | 2014-11-21 | 2020-12-16 | Daikin Industries, Ltd. | Novel fluorinated unsaturated cyclic carbonate and process for producing the same |
| CN115799643A (en) * | 2023-01-18 | 2023-03-14 | 如鲲(江苏)新材料科技有限公司 | Nonaqueous electrolyte solution, lithium ion battery, battery module, battery pack, and electric device |
| CN115799643B (en) * | 2023-01-18 | 2023-09-12 | 如鲲(江苏)新材料科技有限公司 | Nonaqueous electrolyte, lithium ion battery, battery module, battery pack, and power utilization device |
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