JP4671589B2 - Electrolyte for lithium secondary battery and lithium secondary battery - Google Patents
Electrolyte for lithium secondary battery and lithium secondary battery Download PDFInfo
- Publication number
- JP4671589B2 JP4671589B2 JP2003274875A JP2003274875A JP4671589B2 JP 4671589 B2 JP4671589 B2 JP 4671589B2 JP 2003274875 A JP2003274875 A JP 2003274875A JP 2003274875 A JP2003274875 A JP 2003274875A JP 4671589 B2 JP4671589 B2 JP 4671589B2
- Authority
- JP
- Japan
- Prior art keywords
- electrolyte
- lithium secondary
- secondary battery
- carbonate
- group
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0569—Liquid materials characterised by the solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- 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
Description
本発明は、非水性電解質及びこれを含むリチウム二次電池に関するものであり、特に、安全性と高温貯蔵性に優れた非水性電解質及びこれを含むリチウム二次電池に関する。 The present invention relates to a non-aqueous electrolyte and a lithium secondary battery including the non-aqueous electrolyte, and more particularly to a non-aqueous electrolyte excellent in safety and high-temperature storage and a lithium secondary battery including the non-aqueous electrolyte.
非水電解液を用いたリチウム二次電池は、高電圧・高エネルギー密度を有し、かつ、貯蔵性能や低温動作性に優れ、広く携帯用民生電気製品に利用されている。また、この電池を大型化し、電気自動車用や家庭用の夜間電力貯蔵装置として活用していくための研究・開発が盛んに行われている。また、最近では、特に薄型で高容量の電池が求められており、ポリマー電池あるいはラミネート外装の薄型リチウム二次電池の需要が増加している。 A lithium secondary battery using a non-aqueous electrolyte has a high voltage and a high energy density, is excellent in storage performance and low-temperature operability, and is widely used in portable consumer electronic products. In addition, research and development for increasing the size of this battery and using it as a night-time power storage device for electric vehicles and homes has been actively conducted. Recently, there has been a demand for particularly thin and high-capacity batteries, and the demand for polymer batteries or laminate-type thin lithium secondary batteries is increasing.
しかし、これらに利用される溶媒の多くは引火点が低く、燃焼性が高いため、過充電や加熱等により発火、爆発等の危険性がある。そこで、最近ではこの電池の安全性を確保するための提案が増加してきている。例えば、下記特許文献１には、ハロゲン化カーボネートを非水電解液に混合することにより、燃焼性を低減でき、かつ、高負荷特性、低温特性、及び、サイクル特性ともに十分な特性が得られることが示されている。 However, many of the solvents used for these have a low flash point and a high flammability. Therefore, there is a risk of ignition, explosion, etc. due to overcharge or heating. Therefore, recently, proposals for ensuring the safety of this battery are increasing. For example, in Patent Document 1 below, by mixing a halogenated carbonate with a non-aqueous electrolyte, combustibility can be reduced, and sufficient characteristics can be obtained in both high load characteristics, low temperature characteristics, and cycle characteristics. It is shown.
また、下記特許文献２に記載のように、ハロゲン化カーボネートを非水電解液に混合することにより、過充電した際の電池の内圧を上昇させることによって、安全弁を作動させ、安全性を確保することが提案されている。
しかし、ハロゲン化カーボネートを非水電解液に混合したリチウム二次電池においては、６０℃程度の温度で数日間貯蔵すると、負極表面に形成されていた被膜が分解してガスが発生し、電池の内圧が大幅に上昇するという問題がある。特にポリマー電池あるいはラミネート外装の薄型リチウム二次電池においては、分解ガスによって電池厚みが増加することは致命的な問題である。 However, in a lithium secondary battery in which a halogenated carbonate is mixed with a non-aqueous electrolyte, when the film is stored at a temperature of about 60 ° C. for several days, the film formed on the negative electrode surface is decomposed to generate gas, There is a problem that the internal pressure rises significantly. In particular, in a polymer battery or a thin lithium secondary battery with a laminate exterior, it is a fatal problem that the battery thickness increases due to the decomposition gas.
また、ポリマー電池あるいはラミネート外装の薄型リチウム二次電池においては、過充電に伴う過度に急激な内圧上昇で電池が膨張変形し、内部ショートを発生するといった問題が顕在化している。特に、放電状態から大電流で過充電した際には、リチウム析出によって更に内部ショートし易くなるために、安全性の確保が更に困難になるという問題が起きている。 In addition, in a polymer battery or a laminated lithium thin battery, a problem has arisen that the battery expands and deforms due to an excessively rapid increase in internal pressure due to overcharge and an internal short circuit occurs. In particular, when the battery is overcharged with a large current from a discharged state, the internal short circuit is more likely to occur due to lithium deposition, which causes a problem that it is more difficult to ensure safety.
本発明は、上記事情に鑑みてなされたものであって、安全性に優れると共に、高温貯蔵時のガス発生を防止することが可能な非水性電解質及びこれを含むリチウム二次電池を提供することを目的とする。 The present invention has been made in view of the above circumstances, and provides a non-aqueous electrolyte that is excellent in safety and can prevent gas generation during high-temperature storage, and a lithium secondary battery including the non-aqueous electrolyte. With the goal.
上記の目的を達成するために、本発明の好ましい第１の実施形態によると、本発明は環状カーボネート及びγ−ブチロラクトンを含む非水性有機溶媒、ハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基を有するエステル化合物並びに少なくともＬｉＢＦ ４ を含む２つ以上の塩を含むリチウム二次電池用電解質を提供する。 In order to achieve the above object, according to a first preferred embodiment of the present invention, the present invention provides a non-aqueous organic solvent comprising a cyclic carbonate and γ-butyrolactone, a halogen group, a cyano group (CN) and a nitro group (NO An electrolyte for a lithium secondary battery comprising an ester compound having an electron withdrawing group selected from the group consisting of 2 ) and two or more salts containing at least LiBF 4 is provided.
電子吸引基を有するエステル化合物の具体的な例としてはフルオロエチレンカーボネート、ジフルオロエチレンカーボネート、クロロエチレンカーボネート、ジクロロエチレンカーボネート、ブロモエチレンカーボネート、ジブロモエチレンカーボネート、ニトロエチレンカーボネート、シアノエチレンカーボネート、及びこれらの混合物などを列挙することができる。 Specific examples of ester compounds having an electron withdrawing group include fluoroethylene carbonate, difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, and mixtures thereof. Can be enumerated.
本発明の好ましい第２の実施形態によると、本発明はリチウムの吸蔵、放出が可能な負極と、リチウムの吸蔵、放出が可能な正極と、前記電解質とを備えるリチウム二次電池を提供する。
本発明の電解質構成によると、電解質の不燃性を向上させてリチウム二次電池の安全性を高めることができる。また、負極表面にエステル化合物による被膜が形成され、この被膜によって電解質の分解が抑制され、リチウム二次電池のサイクル特性を向上できる。また、負極被膜形成剤によって高温貯蔵時における負極表面の被膜の分解を防止し、ガス発生を抑制することができる。
According to a second preferred embodiment of the present invention, the present invention provides a lithium secondary battery comprising a negative electrode capable of inserting and extracting lithium, a positive electrode capable of inserting and extracting lithium, and the electrolyte.
According to the electrolyte configuration of the present invention, the nonflammability of the electrolyte can be improved and the safety of the lithium secondary battery can be enhanced. Moreover, the coating film by an ester compound is formed in the negative electrode surface, decomposition | disassembly of electrolyte is suppressed by this coating film, and the cycling characteristics of a lithium secondary battery can be improved. Moreover, decomposition | disassembly of the film on the negative electrode surface at the time of high temperature storage can be prevented with a negative electrode film forming agent, and gas generation can be suppressed.
本発明のリチウム二次電池の添加剤として用いられるエステル化合物は環状エステル化合物であるのが好ましい。好ましくは、前記環状エステル化合物の中で下記の［化３］で示されるエチレンカーボネート誘導体を用いることができる。 The ester compound used as an additive for the lithium secondary battery of the present invention is preferably a cyclic ester compound. Preferably, among the cyclic ester compounds, ethylene carbonate derivatives represented by the following [Chemical Formula 3] can be used.
ただし、前記式において、ＸとＹは各々独立的に水素、ハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基であり、前記ＸとＹのうちの少なくとも一つはハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基である。ＸとＹのうちの少なくとも一つがハロゲン基であるハロゲン化エチレンカーボネートを添加すると、電解質の不燃性を向上させてリチウム二次電池の安全性を高めることができる。また、ハロゲン化エチレンカーボネートを添加すると、過充電時にハロゲン化エチレンカーボネートの分解ガスが発生する。この分解ガスによって電池内圧が安全バルブの動作圧力まで上昇するため、安全バルブを早期に作動させ、過充電による電池の破裂を防止することができる。ラミネート外装を有する電池では、この分解ガスによってラミネート外装の熱密封部分を安全バルブとして作動させることができる。 Wherein X and Y are each independently an electron withdrawing group selected from the group consisting of hydrogen, halogen group, cyano group (CN) and nitro group (NO 2 ), At least one of these is an electron withdrawing group selected from the group consisting of a halogen group, a cyano group (CN), and a nitro group (NO 2 ). When halogenated ethylene carbonate in which at least one of X and Y is a halogen group is added, the nonflammability of the electrolyte can be improved and the safety of the lithium secondary battery can be improved. When halogenated ethylene carbonate is added, a decomposition gas of halogenated ethylene carbonate is generated during overcharge. Since the internal pressure of the battery rises to the operating pressure of the safety valve due to the decomposition gas, the safety valve can be actuated early, and the battery can be prevented from rupture due to overcharging. In a battery having a laminate exterior, the heat sealed portion of the laminate exterior can be operated as a safety valve by this decomposition gas.
また、本発明は前記エステル化合物の添加量が電解質に対して０．１質量％以上２５質量％以下、好ましくは０．５質量％以上１０質量％以下の範囲内にあることを特徴とする。エステル化合物の添加量が０．１質量％未満である場合には、負極表面の被膜が不充分になり、サイクル特性が低下するため好ましくなく、また、エステル化合物の添加量が２５質量％を超える場合には、電解質の粘度が増大してサイクル特性が低下するため好ましくない。 In addition, the present invention is characterized in that the amount of the ester compound added is in the range of 0.1 mass % to 25 mass %, preferably 0.5 mass % to 10 mass % with respect to the electrolyte. When the addition amount of the ester compound is less than 0.1% by mass , the coating on the negative electrode surface becomes insufficient and the cycle characteristics are deteriorated, which is not preferable, and the addition amount of the ester compound exceeds 25% by mass. In such a case, the viscosity of the electrolyte increases and the cycle characteristics deteriorate, which is not preferable.
また、前記電解質に対するＬｉＢＦ４の添加量が０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲内にあることが好ましい。 The amount of LiBF 4 relative to the electrolyte is preferably in the range of 0.001 mol / L or more 1 mol / L.
この構成によって、ＬｉＢＦ４が負極表面の被膜に取り込まれて被膜が改質され、高温貯蔵時の被膜分解が防止されてガス発生を抑制することができる。また、過充電時の過度で急激なガス発生を抑制し、ラミネート外装電池の膨脹変形による内部ショートを防止して安全性を高めることができる。
With this configuration, LiBF 4 is taken into the coating on the negative electrode surface and the coating is modified, so that the coating is not decomposed during high-temperature storage, and gas generation can be suppressed. Further, to suppress the rapid gassing excessive overcharge, it is possible to improve safety by preventing the internal short-preparative by expansion deformation of the laminate-sheathed cell.
また、ＬｉＢＦ４の添加量が０．００１ｍｏｌ／Ｌ未満である場合には、高温貯蔵時の被膜分解を抑制できないため好ましくなく、ＬｉＢＦ４の添加量が１ｍｏｌ／Ｌを超える場合には、サイクル特性が劣化するため好ましくない。 Further, when the addition amount of LiBF 4 is less than 0.001 mol / L, it is not preferable because the coating cannot be decomposed during high-temperature storage, and when the addition amount of LiBF 4 exceeds 1 mol / L, cycle characteristics are not achieved. Is not preferable because it deteriorates.
前記電解質において環状カーボネートはエチレンカーボネート、プロピレンカーボネートまたはこれらの混合物が好ましく、エチレンカーボネートがさらに好ましい。前記環状カーボネートは非水性有機溶媒に対して５０体積％以下、好ましくは５体積％乃至３０体積％、一層好ましくは５体積％乃至２０体積％、更に一層好ましくは５体積％乃至１５体積％以下で用いられる。 In the electrolyte, the cyclic carbonate is preferably ethylene carbonate, propylene carbonate or a mixture thereof, more preferably ethylene carbonate. The cyclic carbonate is 50% by volume or less, preferably 5% by volume to 30% by volume, more preferably 5% by volume to 20% by volume, and still more preferably 5% by volume to 15% by volume with respect to the non-aqueous organic solvent. Used.
前記電解質においてγ-ブチロラクトンは非水性有機溶媒に対して１体積％乃至９０体積％の範囲内で添加されるのが好ましく、１０体積％乃至６０体積％の範囲内で添加されるのがさらに好ましい。
また、前記電解質は低粘度溶媒をさらに含み、前記低粘度溶媒が非水性有機溶媒に対して１体積％乃至５０体積％の範囲内で添加されているのが好ましい。
In the electrolyte, γ-butyrolactone is preferably added in the range of 1% by volume to 90% by volume with respect to the non-aqueous organic solvent, and more preferably in the range of 10% by volume to 60% by volume. .
The electrolyte further includes a low-viscosity solvent, and the low-viscosity solvent is preferably added in a range of 1% by volume to 50% by volume with respect to the non-aqueous organic solvent.
また、本発明では、リチウムの吸蔵、放出が可能な負極と、リチウムの吸蔵、放出が可能な正極と、フッ素化環状エステルが添加された電解質を備えたリチウム二次電池を構成してもよい。この構成によれば、電解質の不燃性を向上させてリチウム二次電池の安全性を高めることができる。また、負極表面にフッ素化環状エステルによる被膜が形成され、この被膜によって電解質の分解が抑制され、リチウム二次電池のサイクル特性を向上できる。 In the present invention, a lithium secondary battery including a negative electrode capable of inserting and extracting lithium, a positive electrode capable of inserting and extracting lithium, and an electrolyte added with a fluorinated cyclic ester may be configured. . According to this structure, the nonflammability of electrolyte can be improved and the safety | security of a lithium secondary battery can be improved. In addition, a film made of a fluorinated cyclic ester is formed on the negative electrode surface, and the decomposition of the electrolyte is suppressed by this film, and the cycle characteristics of the lithium secondary battery can be improved.
また本発明のリチウム二次電池は、先に記載のリチウム二次電池であり、前記電解質に、負極被膜形成剤が添加されていることが好ましい。この構成により、高温貯蔵時における負極表面の被膜の分解を防止し、ガス発生を抑制することができる。 The lithium secondary battery of the present invention is the lithium secondary battery described above, and it is preferable that a negative electrode film forming agent is added to the electrolyte. With this configuration, decomposition of the coating on the negative electrode surface during high-temperature storage can be prevented, and gas generation can be suppressed.
また本発明のリチウム二次電池は、先に記載のリチウム二次電池であり、前記フッ素化環状エステルがフッ化エチレンカーボネートであることが好ましい。この構成により、電解質の不燃性を向上させてリチウム二次電池の安全性を高めることができる。また、フッ化エチレンカーボネートを添加すると、過充電時にフッ化エチレンカーボネートの分解ガスが発生する。この分解ガスにより電池内圧が安全弁の動作圧力まで上昇するので、安全弁を早期に作動させて、過充電による電池の破裂を防止することができる。ラミネート外装を有する電池においては、この分解ガスによって、ラミネート外装の熱封止部分を安全弁として作動させることができる。 The lithium secondary battery of the present invention is a lithium secondary battery described above, it is preferable that the fluorinated cyclic ester is fluorinated ethylene carbonate. With this configuration, the nonflammability of the electrolyte can be improved and the safety of the lithium secondary battery can be enhanced. Further, when fluorinated ethylene carbonate is added, a decomposition gas of fluorinated ethylene carbonate is generated during overcharge. Since the internal pressure of the battery rises to the operating pressure of the safety valve due to the decomposition gas, the safety valve can be actuated early to prevent the battery from being ruptured due to overcharging. In a battery having a laminate exterior, the heat sealing portion of the laminate exterior can be operated as a safety valve by this decomposition gas.
また本発明のリチウム二次電池は、先に記載のリチウム二次電池であり、前記フッ素化環状エステルの添加量が電解質に対して０．１質量％以上２５質量％以下、好ましくは０．５質量％以上１０質量％以下の範囲内にあることが好ましい。フッ素化環状エステルの添加量が０．１質量％未満であると、負極表面の皮膜の形成が不十分となり、サイクル特性が低下するので好ましくなく、またフッ素化環状エステルの添加量が２５質量％を超えると、電解質の粘度が増大してサイクル特性が低下するので好ましくない。 Further, the lithium secondary battery of the present invention is the lithium secondary battery described above, and the addition amount of the fluorinated cyclic ester is 0.1% by mass or more and 25% by mass or less, preferably 0.5% with respect to the electrolyte. It is preferable to be in the range of not less than 10% by mass and not more than 10% by mass . When the amount of the fluorinated cyclic ester is less than 0.1 wt%, formation of the film of negative electrode surface becomes insufficient, it is not preferable because the cycle characteristics are lowered, the addition amount of the fluorinated cyclic ester 25 wt% Exceeding this is not preferable because the viscosity of the electrolyte increases and the cycle characteristics deteriorate.
また本発明のリチウム二次電池においては、前記負極被膜形成剤がＬｉＢＦ４であり、前記電解質に対する前記負極被膜形成剤の添加量が０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲内にあり、前記電解質にＬｉＰＦ６が０．１ｍｏｌ／Ｌ以上１．５ｍｏｌ／Ｌ以下の範囲内で添加されていることが好ましい。 In the lithium secondary battery of the present invention, the negative electrode film forming agent is LiBF 4 , and the amount of the negative electrode film forming agent added to the electrolyte is in the range of 0.001 mol / L to 1 mol / L, it is preferable that LiPF 6 is added in a range of 0.1 mol / L or more 1.5 mol / L in the electrolyte.
この構成により、ＬｉＢＦ４が負極表面の被膜に取り込まれて被膜が改質され、高温貯蔵時の被膜分解が防止されてガス発生を抑制することができる。また、過充電時の過度に急激なガス発生を抑制し、ラミネート外装電池の膨張変形による内部ショートを防ぎ安全性を高めることができる。
また、負極被膜形成剤の添加量が０．００１ｍｏｌ／Ｌ未満であると、高温貯蔵時の被膜分解を抑制できないので好ましくなく、負極被膜形成剤の添加量が０．００１ｍｏｌ／Ｌを越えると、サイクル特性が劣化するので好ましくない。
With this configuration, LiBF 4 is taken into the coating on the negative electrode surface and the coating is modified, so that the decomposition of the coating during high-temperature storage is prevented and gas generation can be suppressed. In addition, excessively rapid gas generation during overcharging can be suppressed, and an internal short circuit due to expansion deformation of the laminated exterior battery can be prevented to improve safety.
In addition, if the addition amount of the negative electrode film forming agent is less than 0.001 mol / L, it is not preferable because the decomposition of the film during high-temperature storage cannot be suppressed, and if the addition amount of the negative electrode film forming agent exceeds 0.001 mol / L, Since cycle characteristics deteriorate, it is not preferable.
また本発明のリチウム二次電池においては、前記電解質にγ―ブチロラクトンが１体積％以上９０体積％以下の範囲内で添加されていることが好ましい。 In the lithium secondary battery of the present invention, it is preferable that γ-butyrolactone is added to the electrolyte in a range of 1% by volume to 90% by volume.
また本発明のリチウム二次電池においては、前記電解質にフッ化エーテルが１体積％以上５０体積％以下の範囲内で添加されていることが好ましい。 Moreover, in the lithium secondary battery of this invention, it is preferable that fluoride ether is added to the said electrolyte within the range of 1 volume% or more and 50 volume% or less.
以上、詳細に説明したように、本発明のリチウム二次電池によれば、非水電解質に添加された電子吸引基を有するエステル化合物によって被膜が形成され、この被膜によって電解質の分解が抑制されて、リチウム二次電池のサイクル特性を向上させることができる。前記エステル化合物のうち、フッ素化環状エステルは引火点及び燃焼熱の面で有利な難燃性電解質を形成するので電池の安全性を一層高めることができる。また、負極表面に電子吸引基を有するエステル化合物とＬｉＢＦ４によるＢを含む被膜が形成され、この被膜によって電解質の分解が抑制され、リチウム二次電池の高温特性を向上できる。 As described above in detail, according to the lithium secondary battery of the present invention, a film is formed by the ester compound having an electron withdrawing group added to the non-aqueous electrolyte, and the decomposition of the electrolyte is suppressed by this film. The cycle characteristics of the lithium secondary battery can be improved. Among the ester compounds, the fluorinated cyclic ester forms a flame retardant electrolyte that is advantageous in terms of flash point and combustion heat, so that the safety of the battery can be further enhanced. In addition, a film containing an ester compound having an electron withdrawing group and B by LiBF 4 is formed on the negative electrode surface, and the decomposition of the electrolyte is suppressed by this film, and the high temperature characteristics of the lithium secondary battery can be improved.
また本発明のリチウム二次電池によれば、電子吸引基を有するエステル化合物がフッ化エチレンカーボネートであり、過充電時にフッ化エチレンカーボネートの分解ガスが発生し、電池内圧が速やかに上昇して安全弁等により外部に放出されるので、過充電による電池の熱暴走を防止することができる。 Further, according to the lithium secondary battery of the present invention, the ester compound having an electron withdrawing group is fluorinated ethylene carbonate, a decomposition gas of fluorinated ethylene carbonate is generated at the time of overcharging, and the internal pressure of the battery rises quickly, so that the safety valve Therefore, it is possible to prevent thermal runaway of the battery due to overcharging.
また本発明のリチウム二次電池によれば、負極被膜形成剤がＬｉＢＦ４であり、このＬｉＢＦ４が負極表面の被膜に取り込まれて被膜が改質され、高温貯蔵時の被膜分解が防止されてガス発生を抑制することができる。 Further, according to the lithium secondary battery of the present invention, the negative electrode film forming agent is LiBF 4 , and this LiBF 4 is taken into the film on the negative electrode surface to modify the film and prevent the film from being decomposed during high-temperature storage. Gas generation can be suppressed.
以下、本発明の好ましい実施の形態を図面を参照して説明する。
本発明の第１の実施形態の電解質は環状カーボネート及びγ−ブチロラクトンを含む非水性有機溶媒、電子吸引基を有するエステル化合物並びに２つ以上の塩を含む。
また、本発明の第２の実施形態のリチウム二次電池は、リチウムの吸蔵、放出が可能な負極と、リチウムの吸蔵、放出が可能な正極と、前記第１の実施形態による電解質とを具備してなる。
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The electrolyte of the first embodiment of the present invention includes a non-aqueous organic solvent containing a cyclic carbonate and γ-butyrolactone, an ester compound having an electron withdrawing group, and two or more salts .
The lithium secondary battery according to the second embodiment of the present invention includes a negative electrode capable of inserting and extracting lithium, a positive electrode capable of inserting and extracting lithium, and the electrolyte according to the first embodiment. Do it.
また、この電解質にはゲル形成化合物が添加されていても良い。ゲル形成化合物が添加された場合はゲル電解質になり、ゲル形成化合物が添加されない場合は液体電解質になる。 Further, a gel-forming compound may be added to the electrolyte. When a gel-forming compound is added, it becomes a gel electrolyte, and when no gel-forming compound is added, it becomes a liquid electrolyte.
前記環状カーボネートはエチレンカーボネート、プロピレンカーボネート、またはこれらの混合物が好ましく、このうち、二重エチレンカーボネートがさらに好ましい。前記環状カーボネートは非水性有機溶媒に対して５０体積％以下、好ましくは５体積％乃至３０体積％、一層好ましくは５体積％乃至２０体積％、更に一層好ましくは５体積％乃至１５体積％以下で用いられる。 The cyclic carbonate is preferably ethylene carbonate, propylene carbonate, or a mixture thereof, and among these, double ethylene carbonate is more preferable. The cyclic carbonate is 50% by volume or less, preferably 5% by volume to 30% by volume, more preferably 5% by volume to 20% by volume, and still more preferably 5% by volume to 15% by volume with respect to the non-aqueous organic solvent. Used.
前記γ-ブチロラクトンは１体積％乃至９０体積％の範囲内で添加されるのが好ましく、１０体積％乃至６０体積％の範囲内で添加されるのがさらに好ましい。 The γ-butyrolactone is preferably added in the range of 1% by volume to 90% by volume, and more preferably in the range of 10% by volume to 60% by volume.
また、前記電解質は低粘度溶媒をさらに含み、前記低粘度溶媒が１体積％以上５０体積％以下の範囲内で添加されているのが好ましい。前記低粘度溶媒としてはジメチルカーボネート、メチルエチルカーボネート、ジエチルカーボネート、フルオロエーテル（フッ化エーテル）のうちのいずれか１種以上を含むことが好ましく、特にフルオロエーテルが好ましい。これらの低粘度溶媒を環状カーボネートとγ-ブチロラクトンに添加することで、電解質自体の粘度を下げてイオン伝導度を高めることができる。ただし、フルオロエーテルを除いてこれら低粘度溶媒は引火点が低いので、過度に添加して電解質の引火点を下げないように注意を払う必要がある。 Moreover, it is preferable that the said electrolyte further contains a low-viscosity solvent and the said low-viscosity solvent is added within the range of 1 volume% or more and 50 volume% or less. The low-viscosity solvent preferably contains at least one of dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, and fluoroether (fluorinated ether), and particularly preferably fluoroether. By adding these low-viscosity solvents to the cyclic carbonate and γ-butyrolactone, the viscosity of the electrolyte itself can be lowered to increase the ionic conductivity. However, with the exception of fluoroethers, these low viscosity solvents have a low flash point, so care must be taken not to add too much to lower the flash point of the electrolyte.
また、上記のフルオロエーテルとしては、ＨＣＦ２（ＣＦ２）３ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２（ＣＦ２）３ＣＨ２ＯＣＦ２ＣＦＨＣＦ３のうちの１種以上が好ましい。
As the fluoroether above, HCF 2 (CF 2) 3 CH 2
前記エステル化合物は電気陰性度の大きい電子吸引基（ｅｌｅｃｔｒｏｎ ｗｉｔｈｄｒａｗｉｎｇ ｇｒｏｕｐ）を有する。前記電子吸引基の例としてはハロゲン基、シアノ基（ＣＮ）、ニトロ基（ＮＯ２）などを挙げることができる。 The ester compound has an electron withdrawing group having a high electronegativity. Examples of the electron withdrawing group include a halogen group, a cyano group (CN), and a nitro group (NO 2 ).
前記エステル化合物は環状カーボネートであるのが好ましい。このような環状カーボネートの中で下記の［化４］で示されるエチレンカーボネート誘導体が好ましく用いることができる。 The ester compound is preferably a cyclic carbonate. Among such cyclic carbonates, ethylene carbonate derivatives represented by the following [Chemical Formula 4] can be preferably used.
ただし、前記式において、ＸとＹは各々独立的に水素、ハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基であり、前記ＸとＹのうちの少なくとも一つはハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基である。 Wherein X and Y are each independently an electron withdrawing group selected from the group consisting of hydrogen, halogen group, cyano group (CN) and nitro group (NO 2 ), At least one of these is an electron withdrawing group selected from the group consisting of a halogen group, a cyano group (CN), and a nitro group (NO 2 ).
前記エステル化合物は電解質に対して０．１質量％以上２５質量％以下の、好ましくは０．５質量％以上１０質量％以下の量で添加される。前記エステル化合物の使用量が０．１質量％未満である場合には電池内部でのガス発生抑制効果を期待しがたく、２５質量％を超える場合には電池の可逆性を損傷させる程度の厚い導電性被膜が形成されるので、サイクル寿命特性など電池性能が低下する問題が発生する。 The ester compound of 0.1 wt% to 25 wt% with respect to the electrolyte, is preferably added in an amount of less than 10% by mass to 0.5% by mass. When the amount of the ester compound used is less than 0.1% by mass, it is difficult to expect the effect of suppressing gas generation inside the battery, and when it exceeds 25% by mass , it is thick enough to damage the reversibility of the battery. Since the conductive film is formed, there arises a problem that the battery performance is deteriorated such as cycle life characteristics.
前記２つ以上の塩としてはＬｉＰＦ６、Ｌｉ［Ｎ（ＳＯ２Ｃ２Ｆ５）２］、Ｌｉ［Ｂ（ＯＣＯＣＦ３）４］、Ｌｉ［Ｂ（ＯＣＯＣ２Ｆ５）４］のうちのいずれか一つまたは２以上の混合物を含む第１塩とＬｉＢＦ４の第２塩を含むのが好ましく、第１塩の主用途は電解塩、第２塩の主用途は負極被膜形成物質と考えている。ＬｉＰＦ６またはＢＥＴＩ塩（Ｌｉ［Ｎ（ＳＯ２Ｃ２Ｆ５）２］）のうちのいずれか一方または両方を含む第１塩とＬｉＢＦ４の第２塩を含むことがさらに好ましく、ＬｉＰＦ６の第１塩とＬｉＢＦ４の第２塩を含むことが最も好ましい。前記第１塩の非水電解質における濃度は０．１ｍｏｌ／Ｌ以上１．５ｍｏｌ／Ｌ以下であるのが好ましい。電解質中にこれら塩が含まれるので、電解質自体のイオン伝導度を高めることができる。 The two or more salts include LiPF 6 , Li [N (SO 2 C 2 F 5 ) 2 ], Li [B (OCOCF 3 ) 4 ], Li [B (OCOC 2 F 5 ) 4 ] preferably comprises one or more mixture first second salt salt and LiBF 4 including whether the main purpose of the first salt electrolyte salt, the main purpose of the second salt is considered negative film forming substance Yes. LiPF 6 or BETI salt (Li [N (SO 2 C 2 F 5) 2]) it is more preferably comprising either first second salt salt and LiBF 4, including one or both of, the LiPF 6 it is most preferred to include a second salt of the first salt and LiBF 4. The concentration of the first salt in the non-aqueous electrolyte is preferably 0.1 mol / L or more and 1.5 mol / L or less. Since these salts are contained in the electrolyte, the ionic conductivity of the electrolyte itself can be increased.
本発明ではＬｉＢＦ４と前記エステル化合物を組み合わせて用いることによって負極表面に形成されたエステル化合物による被膜にホウ素（Ｂ）が入っていって、被膜自体が改質される。この改質被膜は熱安定性と電気化学的安定性に優れるため、高温貯蔵時に分解することがなく、分解ガスの発生を抑制することができる。また、この改質被膜は過充電時には容易に分解して分解ガスを発生させるので、安全弁などの作動を早めて分解ガスを早期に外部に放出させ、電池の熱暴走を防止できる。 In the present invention, by using LiBF 4 in combination with the above ester compound, boron (B) is contained in the film of the ester compound formed on the negative electrode surface, and the film itself is modified. Since this modified coating is excellent in thermal stability and electrochemical stability, it is not decomposed during high-temperature storage, and generation of decomposition gas can be suppressed. In addition, since this modified coating is easily decomposed and generates decomposition gas when overcharged, the operation of a safety valve or the like is expedited to quickly release the decomposition gas to the outside, thereby preventing thermal runaway of the battery.
また、ＬｉＢＦ４をＬｉＰＦ６と共に用いた場合には、負極表面の被膜にＬｉＢＦ４及びＬｉＰＦ６が取り込まれて、被膜が改質される。この２種類の塩を取り込んだ改質被膜は熱安定性に特に優れるため、高温貯蔵時における分解ガスの発生を大幅に抑制できる。 When LiBF 4 is used together with LiPF 6 , LiBF 4 and LiPF 6 are taken into the coating on the negative electrode surface, and the coating is modified. Since the modified coating film incorporating these two kinds of salts is particularly excellent in thermal stability, generation of decomposition gas during high-temperature storage can be greatly suppressed.
電解質に対するＬｉＢＦ４の添加量は０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲が好ましく、０．０１ｍｏｌ／Ｌ以上０．５ｍｏｌ／Ｌ以下の範囲が一層好ましい。ＬｉＢＦ４の添加量が０．００１ｍｏｌ／Ｌ未満であると、高温貯蔵時の被膜分解を抑制できないので好ましくなく、ＬｉＢＦ４の添加量が１ｍｏｌ／Ｌを超えると、サイクル特性が劣化するので好ましくない。 The amount of LiBF 4 added to the electrolyte is preferably in the range of 0.001 mol / L to 1 mol / L, and more preferably in the range of 0.01 mol / L to 0.5 mol / L. If the amount of LiBF 4 added is less than 0.001 mol / L, it is not preferable because the coating cannot be decomposed during high-temperature storage, and if the amount of LiBF 4 added exceeds 1 mol / L, it is not preferable because cycle characteristics deteriorate. .
本発明の第３の実施形態のリチウム二次電池は、リチウムの吸蔵、放出が可能な負極と、リチウムの吸蔵、放出が可能な正極と、フッ素化環状エステルが添加されてなる電解質とを具備して構成されている。 A lithium secondary battery according to a third embodiment of the present invention includes a negative electrode capable of inserting and extracting lithium, a positive electrode capable of inserting and extracting lithium, and an electrolyte to which a fluorinated cyclic ester is added. Configured.
前記第３の実施形態のリチウム二次電池に使用される電解質は、非水電解液にフッ素化環状エステルが添加されてなるものであり、更にガス発生抑制剤が添加されてなるものである。またこの電解質にはゲル形成化合物が添加されていても良い。ゲル形成化合物が添加された場合はゲル電解質となり、ゲル形成化合物が添加されない場合は液体電解質となる。 The electrolyte used in the lithium secondary battery of the third embodiment is obtained by adding a fluorinated cyclic ester to a nonaqueous electrolytic solution, and further by adding a gas generation inhibitor. Further, a gel-forming compound may be added to the electrolyte. When a gel forming compound is added, it becomes a gel electrolyte, and when no gel forming compound is added, it becomes a liquid electrolyte.
前記非水電解質は、環状エステルと低粘度溶媒とリチウム塩とが混合されて構成されている。環状カーボネートとしては、例えば、エチレンカーボネート、ブチレンカーボネート、プロピレンカーボネート、γ−ブチロラクトン等のうちの１種以上を含むものが好ましい。これらの環状カーボネートはリチウムイオンと溶媒和しやすいため、電解質自体のイオン伝導度を高めることができる。 The non-aqueous electrolyte is configured by mixing a cyclic ester, a low viscosity solvent, and a lithium salt. As cyclic carbonate, what contains 1 or more types in ethylene carbonate, butylene carbonate, propylene carbonate, (gamma) -butyrolactone, etc. is preferable, for example. Since these cyclic carbonates easily solvate with lithium ions, the ionic conductivity of the electrolyte itself can be increased.
また低粘度溶媒としては、例えば、ジメチルカーボネート、メチルエチルカーボネート、ジエチルカーボネート、フルオロエーテル（フッ化エーテル）のうちのいずれか１種以上を含むものが好ましく、特にフルオロエーテルが好ましい。これらの低粘度溶媒を環状カーボネートに添加することで、電解質自体の粘度を下げてイオン伝導度を高めることができる。ただし、フルオロエーテルを除いてこれら低粘度溶媒は引火点が低いので、過剰に添加して電解質の引火点を下げないように注意を払う必要がある。 Moreover, as a low-viscosity solvent, what contains any 1 or more types in dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, and fluoro ether (fluorinated ether) is preferable, for example, and fluoro ether is especially preferable. By adding these low viscosity solvents to the cyclic carbonate, the viscosity of the electrolyte itself can be lowered and the ionic conductivity can be increased. However, with the exception of fluoroethers, these low-viscosity solvents have a low flash point, so care must be taken not to add too much to lower the flash point of the electrolyte.
尚、上記のフルオロエーテルとしては、ＨＣＦ２（ＣＦ２）３ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２（ＣＦ２）３ＣＨ２ＯＣＦ２ＣＦＨＣＦ３などのうちの１種以上が好ましい。
As the fluoroether above, HCF 2 (CF 2) 3 CH 2
更にリチウム塩（溶質）としては、ＬｉＰＦ６、ＬｉＢＦ４、Ｌｉ［Ｎ（ＳＯ２Ｃ２Ｆ ５ ）２］、Ｌｉ［Ｂ（ＯＣＯＣＦ３）４］、Ｌｉ［Ｂ（ＯＣＯＣ２Ｆ５）４］を用いることができるが、ＬｉＰＦ６またはＢＥＴＩ塩（Ｌｉ［Ｎ（ＳＯ２Ｃ２Ｆ５）２］）のいずれか一方または両方を用いることが好ましい。これらリチウム塩の非水電解質における濃度は、０．５ｍｏｌ／Ｌ以上１．５ｍｏｌ／Ｌ以下であることが好ましい。電解質中にこれらのリチウム塩が含まれるので、電解質自体のイオン伝導度を高めることができる。
Furthermore, as a lithium salt (solute), LiPF 6 , LiBF 4 , Li [N (SO 2 C 2 F 5 ) 2 ], Li [B (OCOCF 3 ) 4 ], Li [B (OCOC 2 F 5 ) 4 ] However, it is preferable to use one or both of LiPF 6 and BETI salt (Li [N (SO 2 C 2 F 5 ) 2 ]). The concentration of these lithium salts in the nonaqueous electrolyte is preferably from 0.5 mol / L to 1.5 mol / L. Since these lithium salts are contained in the electrolyte, the ionic conductivity of the electrolyte itself can be increased.
次に、フッ素化環状エステルとしては、フッ化エチレンカーボネートを例示することができ、特にモノフルオロエチレンカーボネートが好ましい。フッ素化環状エステルを電解質に添加することにより、電解質の不燃性を向上させてリチウム二次電池の安全性を高めることができる。また、負極表面にフッ素化環状エステルによる被膜が形成され、この被膜によって電解質の分解が抑制され、リチウム二次電池のサイクル特性を向上できる。 Next, examples of the fluorinated cyclic ester include fluorinated ethylene carbonate, and monofluoroethylene carbonate is particularly preferable. By adding a fluorinated cyclic ester to the electrolyte, the nonflammability of the electrolyte can be improved and the safety of the lithium secondary battery can be increased. In addition, a film made of a fluorinated cyclic ester is formed on the negative electrode surface, and the decomposition of the electrolyte is suppressed by this film, and the cycle characteristics of the lithium secondary battery can be improved.
特に、フッ素化環状エステルとしてフッ化エチレンカーボネートを添加すると、過充電時にフッ化エチレンカーボネートの分解ガスが発生し、この分解ガスにより電池内圧が速やかに上昇し、この分解ガスが安全弁などによって早期に放出されるので、過充電による電池の熱暴走を防止することができる。ラミネート外装を有する電池においては、内圧上昇によりラミネートの封止部分が開口し、分解ガスを放出させることができる。 In particular, when fluorinated ethylene carbonate is added as a fluorinated cyclic ester, a decomposition gas of fluorinated ethylene carbonate is generated during overcharge, and this decomposition gas quickly increases the internal pressure of the battery. Since the battery is discharged, thermal runaway of the battery due to overcharging can be prevented. In a battery having a laminate exterior, a sealing portion of the laminate is opened due to an increase in internal pressure, and a decomposition gas can be released.
電解質に対するフッ素化環状エステルの添加量は、０．１質量％以上２５質量％以下、好ましくは０．５質量％以上１０質量％以下の範囲が一層好ましい。フッ素化環状エステルの添加量が０．１質量％未満であると、負極表面の皮膜の形成が不十分となり、サイクル特性が低下するので好ましくなく、またフッ素化環状エステルの添加量が２５質量％を越えると、電解質の粘度が増大してサイクル特性が低下するので好ましくない。 The amount of the fluorinated cyclic ester added to the electrolyte is more preferably 0.1% by mass or more and 25% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less. When the amount of the fluorinated cyclic ester is less than 0.1 wt%, formation of the film of negative electrode surface becomes insufficient, it is not preferable because the cycle characteristics are lowered, the addition amount of the fluorinated cyclic ester 25 wt% Exceeding this is not preferable because the viscosity of the electrolyte increases and the cycle characteristics deteriorate.
次に、ガス発生抑制剤としては、ＬｉＢＦ４を例示することができる。ＬｉＢＦ４とフッ化エチレンカーボネートとを組み合わせて用いることで、負極表面に形成されたフッ化エチレンカーボネートによる被膜にＬｉＢＦ４が取り込まれて、被膜自体が改質される。この改質被膜は熱安定性に優れるため、高温貯蔵時に分解することがなく、分解ガスの発生を抑制することができる。またこの改質被膜は過充電時には容易に分解して分解ガスを発生させるので、安全弁などの作動を早めて分解ガスを早期に外部に放出させ、電池の熱暴走を防止できる。 Next, LiBF 4 can be illustrated as a gas generation inhibitor. By using a combination of LiBF 4 and fluorinated ethylene carbonate, LiBF 4 is taken into the film of fluorinated ethylene carbonate formed on the negative electrode surface, and the film itself is modified. Since this modified coating is excellent in thermal stability, it is not decomposed during high-temperature storage, and generation of decomposition gas can be suppressed. In addition, since this modified coating is easily decomposed and generates a decomposition gas when overcharged, the operation of a safety valve or the like is expedited to quickly release the decomposition gas to the outside, thereby preventing thermal runaway of the battery.
また、ＬｉＢＦ４をＬｉＰＦ６と共に用いた場合には、負極表面の被膜にＬｉＢＦ４及びＬｉＰＦ６が取り込まれて、被膜が改質される。この２種類の塩を取り込んだ改質被膜は熱安定性に特に優れるため、高温貯蔵時における分解ガスの発生を大幅に抑制できる。 When LiBF 4 is used together with LiPF 6 , LiBF 4 and LiPF 6 are taken into the coating on the negative electrode surface, and the coating is modified. Since the modified coating film incorporating these two kinds of salts is particularly excellent in thermal stability, generation of decomposition gas during high-temperature storage can be greatly suppressed.
電解質に対する負極被膜形成剤の添加量は０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲が好ましく、０．０１ｍｏｌ／Ｌ以上０．１ｍｏｌ／Ｌ以下の範囲が一層好ましい。負極被膜形成剤の添加量が０．００１ｍｏｌ／Ｌ未満であると、高温貯蔵時の被膜分解を抑制できないので好ましくなく、負極被膜形成剤の添加量が１ｍｏｌ／Ｌを越えると、サイクル特性が劣化するので好ましくない。 The amount of the negative electrode film forming agent added to the electrolyte is preferably in the range of 0.001 mol / L to 1 mol / L, and more preferably in the range of 0.01 mol / L to 0.1 mol / L. If the amount of the negative electrode film forming agent added is less than 0.001 mol / L, it is not preferable because the decomposition of the film during high-temperature storage cannot be suppressed, and if the amount of the negative electrode film forming agent exceeds 1 mol / L, the cycle characteristics deteriorate. This is not preferable.
また、電解質にゲル形成化合物が添加されていても良い。ゲル形成化合物が添加されるとこのゲル形成化合物に非水電解液やフッ素化環状エステル等が保持されてゲル電解質となる。このゲル電解質を用いたリチウム二次電池は、高温貯蔵時における分解ガスの発生を更に抑制できる。 Further, a gel-forming compound may be added to the electrolyte. When a gel-forming compound is added, a non-aqueous electrolytic solution, a fluorinated cyclic ester, or the like is held in the gel-forming compound to become a gel electrolyte. The lithium secondary battery using this gel electrolyte can further suppress the generation of decomposition gas during high-temperature storage.
ゲル形成化合物は、２官能基以上（つまり、２以上の官能基）を有するポリアクリレートを例示することができ、一層具体的にはポリエチレングリコールジメタクリレート、ポリエチレングリコールアクリレートを例示できる。これらはいずれも加熱によりラジカル重合して重合体を形成するものであり、ゲル形成化合物の種類及び濃度を適宜選択することにより、ゲル状の電解質とすることができる。また、ゲル形成化合物として、ポリエチレンオキシド（ＰＥＯ）、ポリプロピレンオキシド（ＰＰＯ）、ポリアクリロニトリル（ＰＡＮ）、ポリフッ化ビニリデン（ＰＶＤＦ）、ポリメタクリレート（ＰＭＡ）、ポリメチルメタクリレート（ＰＭＭＡ）あるいはその重合体を用いても良い。また、３つ以上の水酸基（−ＯＨ）を有する（ポリエステル）ポリオールの水酸基（−ＯＨ）のうちの一部または全部を（メタ）アクリル酸エステルに変換させ、残余の一部水酸基の（メタ）アクリル酸エステルに置換されない未反応水酸基（−ＯＨ）がラジカル反応性のない基で置換されたポリ（エステル）（メタ）アクリレートをゲル形成化合物として用いることもできる。本発明に用いられるポリ（エステル）（メタ）アクリレートは大韓民国特許出願第２００２−００１８２６４号に記載された方法で製造できる。
本発明の電解質は有機過酸化物をさらに含むことができる。有機過酸化物は電池の内部温度が高温に上昇する場合にゲル形成化合物を重合させて高温でのスウェリング抑制効果を一層向上させる。
Examples of the gel-forming compound include polyacrylates having two or more functional groups (that is, two or more functional groups), and more specifically, polyethylene glycol dimethacrylate and polyethylene glycol acrylate. These are all radically polymerized by heating to form a polymer, and a gel electrolyte can be obtained by appropriately selecting the type and concentration of the gel-forming compound. Further, as the gel forming compound, polyethylene oxide (PEO), polypropylene oxide (PPO), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethacrylate (PMA), polymethyl methacrylate (PMMA) or a polymer thereof is used. May be. Further, a part or all of the hydroxyl groups (—OH) of the (polyester) polyol having three or more hydroxyl groups (—OH) is converted into (meth) acrylic acid ester, and the remaining (hydroxy) partially hydroxyl group (meth). Poly (ester) (meth) acrylates in which an unreacted hydroxyl group (—OH) that is not substituted with an acrylate ester is substituted with a group that is not radically reactive can also be used as a gel-forming compound. The poly (ester) (meth) acrylate used in the present invention can be produced by the method described in Korean Patent Application No. 2002-0018264.
The electrolyte of the present invention can further contain an organic peroxide. The organic peroxide polymerizes the gel-forming compound when the internal temperature of the battery rises to a high temperature, and further improves the swelling suppression effect at a high temperature.
前記有機過酸化物は極性部分（親水性部分）である−Ｃ（＝Ｏ）−Ｏ−Ｏ−Ｃ（＝Ｏ）−と、非極性部分（疏水性部分）である炭素数６乃至４０の脂肪族または芳香族炭化水素基領域とに分けることができる。このような過酸化物は電解液と負極、特にカーボン系負極との間で界面活性剤としての役割を果たして負極表面と電解液との間の抵抗を減少させることによって、負極表面で電解液が分解されることを抑制することができる。 The organic peroxide has a polar part (hydrophilic part) —C (═O) —O—O—C (═O) — and a nonpolar part (hydrophobic part) having 6 to 40 carbon atoms. It can be divided into aliphatic or aromatic hydrocarbon group regions. Such a peroxide acts as a surfactant between the electrolyte and the negative electrode, particularly the carbon-based negative electrode, and reduces the resistance between the negative electrode surface and the electrolyte, so that Decomposition can be suppressed.
前記有機過酸化物としては、好ましくは、炭素数６乃至４０の有機過酸化物を用いることができる。好ましい具体的な例としてはイソブチルパーオキシド、ラウロイル（ｌａｕｒｏｙｌ）パーオキシド、ベンゾイルパーオキシド（ｂｅｎｚｏｙｌ ｐｅｒｏｘｉｄｅ）、ｍ−トルオイルパーオキシド（ｍ−ｔｏｌｕｏｙｌ ｐｅｒｏｘｉｄｅ）、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ｔ−ブチルパーオキシバイバーレート、ｔ−ブチルオキシネオデカネート、ジイソプロピルパーオキシジカーボネート、ジエトキシパーオキシジカーボネート、ビス−（４−ｔ−ブチルシクロヘキシル）パーオキシジカーボネート、ジメトキシイソプロピルパーオキシジカーボネート、ジシクロヘキシルパーオキシジカーボネート及び３，３，５−トリメチルヘキサノイルパーオキシドがある。 As the organic peroxide, an organic peroxide having 6 to 40 carbon atoms can be preferably used. Preferred specific examples include isobutyl peroxide, lauroyl peroxide, benzoyl peroxide, m-toluoyl peroxide, t-butylperoxy-2-ethylhexanoate , T-butyl peroxybirate, t-butyloxyneodecanate, diisopropyl peroxydicarbonate, diethoxyperoxydicarbonate, bis- (4-t-butylcyclohexyl) peroxydicarbonate, dimethoxyisopropylperoxydi There are carbonates, dicyclohexyl peroxydicarbonate and 3,3,5-trimethylhexanoyl peroxide.
以下のリチウム二次電池の正極、負極、セパレータに関する説明は本発明の全てのリチウム二次電池に適用される。 The following description regarding the positive electrode, the negative electrode, and the separator of the lithium secondary battery is applied to all the lithium secondary batteries of the present invention.
正極は、正極活物質粉末にポリフッ化ビニリデン等の結着材とカーボンブラック等の導電助材を混合してシート状、扁平円板状等に成形したものを例示でき、更に正極活物質粉末等をシート状、扁平円板状等に成形して金属集電体に積層したものも例示できる。上記の正極活物質としては、コバルト、マンガン、ニッケルから選ばれる少なくとも一種とリチウムとの複合酸化物のいずれか１種以上のものが好ましく、具体的には、下記に記載のリチウム含有化合物が使用されることが好ましい。 The positive electrode can be exemplified by a positive electrode active material powder mixed with a binder such as polyvinylidene fluoride and a conductive additive such as carbon black and formed into a sheet shape, a flat disk shape, etc. Examples thereof include a sheet formed into a sheet, a flat disk, and the like and laminated on a metal current collector. The positive electrode active material is preferably at least one of a composite oxide of at least one selected from cobalt, manganese and nickel and lithium, specifically, the lithium-containing compounds described below are used. It is preferred that
ＬｉｘＭｎ１-ｙＭｙＡ２ （１）
ＬｉｘＭｎ１-ｙＭｙＯ２-ｚＸｚ （２）
ＬｉｘＭｎ２Ｏ４-ｚＸｚ （３）
ＬｉｘＭｎ２-ｙＭｙＭ´ｚＡ４ （４）
ＬｉｘＣｏ１-ｙＭｙＡ２ （５）
ＬｉｘＣｏ１-ｙＭｙＯ２-ｚＸｚ （６）
ＬｉｘＮｉ１-ｙＭｙＡ２ （７）
ＬｉｘＮｉ１-ｙＭｙＯ２-ｚＸｚ （８）
ＬｉｘＮｉ１-ｙＣｏｙＯ２-ｚＸｚ （９）
ＬｉｘＮｉ１-ｙ-ｚＣｏｙＭｚＡα （１０）
ＬｉｘＮｉ１-ｙ-ｚＣｏｙＭｚＯ２-αＸα （１１）
ＬｉｘＮｉ１-ｙ-ｚＭｎｙＭｚＡα （１２）
ＬｉｘＮｉ１-ｙ-ｚＭｎｙＭｚＯ２-αＸα （１３）
ＬｉｘＭｎ２-ｙ-ｚＭｙＭ´ｚＡ４ （１４）
Li x Mn 1- y My A 2 (1)
Li x Mn 1-y M y O 2-z X z (2)
Li x Mn 2 O 4-z X z (3)
Li x Mn 2- y My M'zA 4 (4)
Li x Co 1- y My A 2 (5)
Li x Co 1-y M y O 2-z X z (6)
Li x Ni 1- y My A 2 (7)
Li x Ni 1-y M y O 2-z X z (8)
Li x Ni 1-y Co y O 2-z X z (9)
Li x Ni 1-yz Co y M z A α (10)
Li x Ni 1-yz Co y M z O 2 -α X α (11)
Li x Ni 1-yz Mn y M z A α (12)
Li x Ni 1-yz Mn y M z O 2 -α X α (13)
Li x Mn 2−yz M y M′zA 4 (14)
ただし、前記式において、組成比を示すｘ、ｙ、ｚ及びαは、０．９０≦ｘ≦１．１、０≦ｙ≦０．５、０≦ｚ≦０．５、０≦α＜２の範囲であり、ＭとＭ´は同一であるか互いに異なる元素であってＭｇ、Ａｌ、Ｃｏ、Ｋ、Ｎａ、Ｃａ、Ｓｉ、Ｔｉ、Ｓｎ、Ｖ、Ｇｅ、Ｇａ、Ｂ、Ａｓ、Ｚｒ、Ｎｉ、Ｍｎ、Ｃｒ、Ｆｅ、Ｓｒ、Ｖ及び希土類元素からなる群より選択される元素であり、ＡはＯであり、ＸはＦである。 However, in the above formula, x, y, z and α indicating the composition ratio are 0.90 ≦ x ≦ 1.1, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.5, 0 ≦ α <2. M and M ′ are the same or different elements, and Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, An element selected from the group consisting of Ni, Mn, Cr, Fe, Sr, V and rare earth elements, A is O, and X is F.
またＬｉＦｅＯ２、Ｖ２Ｏ５、ＴｉＳ、ＭｏＳ、有機ジスルフィド化合物または有機ポリスルフィド化合物等のリチウムを吸蔵・放出が可能なものを用いても良い。 The LiFeO 2, V 2 O 5, TiS, MoS, lithium and organic disulfide compound or an organic polysulfide compound may be used one capable of occluding and releasing.
また、電解質がゲル電解質でない場合はセパレータが必須であり、多孔質のポリプロピレンフィルム、多孔質のポリエチレンフィルム等、公知のセパレータを適宜使用できる。 Further, when the electrolyte is not a gel electrolyte, a separator is essential, and known separators such as a porous polypropylene film and a porous polyethylene film can be appropriately used.
次に負極は、リチウムを吸蔵・放出が可能な負極活物質粉末に、ポリフッ化ビニリデン等の結着材と、場合によってカーボンブラック等の導電助材を混合してシート状、扁平円板状等に成形したものを例示でき、更に負極活物質等をシート状、扁平円板状等に成形して金属集電体に積層したものも例示できる。負極活物質としては、層状炭素質材料などを含むことができ、人造黒鉛、天然黒鉛、黒鉛化炭素繊維、黒鉛化メソカーボンマイクロビーズ、非晶質炭素等の炭素質材料を例示できる。前記炭素材物質はｄ００２層間距離（ｉｎｔｅｒｐｌａｎａｒ ｄｉｓｔａｎｃｅ）が３．３５〜３．３８Å（０．３３５〜０．３３８ｎｍ）の範囲であり、Ｘ線回折（Ｘ−ｒａｙ ｄｉｆｆｒａｃｔｉｏｎ）による結晶子サイズＬｃ（ｃｒｙｓｔａｌｌｉｔｅ ｓｉｚｅ）が少なくとも２０ｎｍ以上であり、７００℃以上で発熱ピークを有する物質が好ましい。また、リチウムと合金化が可能な金属質物単体やこの金属質物と炭素質材料を含む複合物も負極活物質として例示できる。リチウムと合金化が可能な金属としては、Ａｌ、Ｓｉ、Ｓｎ、Ｐｂ、Ｚｎ、Ｂｉ、Ｉｎ、Ｍｇ、Ｇａ、Ｃｄ等を例示できる。また負極活物質として金属リチウム箔も使用できる。 Next, the negative electrode is made by mixing a negative electrode active material powder capable of inserting and extracting lithium, a binder such as polyvinylidene fluoride, and a conductive auxiliary agent such as carbon black in some cases, into a sheet shape, a flat disk shape, etc. In addition, a negative electrode active material or the like formed into a sheet shape or a flat disk shape and laminated on a metal current collector can also be exemplified. Examples of the negative electrode active material include layered carbonaceous materials, and examples thereof include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, and amorphous carbon. The carbon material has a d 002 interplanar distance of 3.35 to 3.38 mm (0.335 to 0.338 nm) and a crystallite size Lc (X-ray diffraction). A substance having a crystallite size) of at least 20 nm and an exothermic peak at 700 ° C. or higher is preferable. Moreover, the metal substance simple substance which can be alloyed with lithium, and the composite containing this metal substance and carbonaceous material can be illustrated as a negative electrode active material. Examples of metals that can be alloyed with lithium include Al, Si, Sn, Pb, Zn, Bi, In, Mg, Ga, and Cd. A metal lithium foil can also be used as the negative electrode active material.
負極の表面には、フッ素化環状エステルの反応物を主成分とする被膜が形成される。この被膜は上述したように負極表面における電解質の分解を防止するので、リチウム二次電池のサイクル特性を高めることができる。また、被膜にＬｉＢＦ４が取り込まれることにより被膜自体が改質され、高温貯蔵時に被膜が分解されることはなく、分解ガスの発生を抑制することができる。またこの改質被膜は過充電時には容易に分解して分解ガスを発生させるので、安全弁などの作動を早めて電池の熱暴走を防止できる。ラミネート外装を有する電池においては、この分解ガスをラミネート外装の封止部分から外部に放出させることができる。 On the surface of the negative electrode, a film containing a reaction product of a fluorinated cyclic ester as a main component is formed. As described above, since this coating prevents decomposition of the electrolyte on the negative electrode surface, the cycle characteristics of the lithium secondary battery can be enhanced. Further, by incorporating LiBF 4 into the coating, the coating itself is modified, and the coating is not decomposed during high-temperature storage, and generation of decomposition gas can be suppressed. Further, since this modified coating is easily decomposed and generates a decomposition gas at the time of overcharging, the operation of a safety valve or the like can be accelerated to prevent thermal runaway of the battery. In a battery having a laminate exterior, this decomposition gas can be released to the outside from the sealing portion of the laminate exterior.
上記のリチウム二次電池によれば、電解質の不燃性が向上してリチウム二次電池の安全性を高めることができる。また、負極表面にフッ素化環状エステルによる被膜が形成され、この被膜によって電解質の分解が抑制され、リチウム二次電池のサイクル特性を向上できる。更に、高温貯蔵時に負極表面の被膜が分解されずに分解ガスの発生を抑制することができ、高温時の保存安定性を高めることができる。またこの被膜は過充電時には容易に分解して分解ガスを発生させるので、安全弁などの作動を早めて電池の熱暴走を防止できる。 According to said lithium secondary battery, the nonflammability of electrolyte can improve and the safety | security of a lithium secondary battery can be improved. In addition, a film made of a fluorinated cyclic ester is formed on the negative electrode surface, and the decomposition of the electrolyte is suppressed by this film, and the cycle characteristics of the lithium secondary battery can be improved. Furthermore, the coating on the negative electrode surface is not decomposed during high-temperature storage, and the generation of decomposition gas can be suppressed, and the storage stability at high temperatures can be enhanced. In addition, since this coating easily decomposes and generates decomposition gas during overcharge, the operation of the safety valve or the like can be accelerated to prevent thermal runaway of the battery.
（実験１〜２６のリチウム二次電池の製造）
非水電解質に対してモノフルオロエチレンカーボネート（ＦＥＣ）、ニトロエチレンカーボネート（ＮＥＣ）あるいはシアノエチレンカーボネート（ＣＥＣ）を０乃至２０質量％添加するとともに、第２塩のＬｉＢＦ４を０乃至１ｍｏｌ／Ｌ添加することにより、表１に示す組成の実験１〜２６の電解質を製造した。また、実験１２の電解質にはゲル形成化合物としてポリエチレングリコールジアクリレート（ＰＥＧＤＡ）を３質量％添加した。
(Production of lithium secondary batteries in Experiments 1 to 26)
0 to 20% by mass of monofluoroethylene carbonate (FEC), nitroethylene carbonate (NEC) or cyanoethylene carbonate (CEC) is added to the non-aqueous electrolyte, and 0 to 1 mol / L of the second salt LiBF 4 is added. As a result, the electrolytes of Experiments 1 to 26 having the compositions shown in Table 1 were manufactured. Moreover, 3 mass % of polyethylene glycol diacrylate (PEGDA) was added to the electrolyte of Experiment 12 as a gel formation compound.
表１において、モノフルオロエチレンカーボネート、ニトロエチレンカーボネートあるいはシアノエチレンカーボネートの添加量は質量％で示したが、非水性有機溶媒の組成比は体積％で示し、非水電解質として添加される塩のＬｉＢＦ４、ＬｉＰＦ６及びＢＥＴＩの含量は電解質に対してｍｏｌ／Ｌの単位で記載されている。尚、表１においてＦＥＣはモノフルオロエチレンカーボネート、ＮＥＣはニトロエチレンカーボネート、ＣＥＣはシアノエチレンカーボネートの略であり、ＥＣはエチレンカーボネート、γ−ＢＬはγ−ブチロラクトン、ＤＥＣはジエチルカーボネート、ＰＥＧＤＡはポリエチレングリコールジアクリレート、ＦＥはフロオロエーテル（ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ）の略である。 In Table 1, the addition amount of monofluoroethylene carbonate, nitroethylene carbonate or cyanoethylene carbonate is shown by mass %, but the composition ratio of the non-aqueous organic solvent is shown by volume%, and the LiBF of the salt added as a non-aqueous electrolyte. 4 , LiPF 6 and BETI content is described in units of mol / L with respect to the electrolyte. In Table 1, FEC is monofluoroethylene carbonate, NEC is nitroethylene carbonate, CEC is cyanoethylene carbonate, EC is ethylene carbonate, γ-BL is γ-butyrolactone, DEC is diethyl carbonate, PEGDA is polyethylene glycol Diacrylate and FE are abbreviations for fluoroether (HCF 2 CF 2 CH 2 OCF 2 CF 2 H).
更に表１の表記について補足説明すると、実験１乃至３は各々負極被膜を形成する物質としてＥＣ、ＧＢＬ、及びＦＥＣを用いた比較例であり、実験４乃至１２は負極被膜を形成する物質としてＦＥＣとＬｉＢＦ４を用いた実施例および参考例、実験１３乃至１４は同様の比較例、実験１５乃至２２は同様の実施例である。
実施例の中でポリマーゲル電解質に対する効果を検証するための実験１２を実施した。この時、ポリマーゲル電解質を形成させるために開始剤としてラウロイルパーオキシドをゲル形成化合物含量対比１質量％添加して実施した。
電解液の誘電率に対する効果を検証するために比較例として実験１３と１４を実施した。
また、実験２３と２４は負極被膜を形成する物質としてＦＥＣとＢＥＴＩを用いた比較例である。実験２５と２６は電解塩としてＢＥＴＩを用い、このうちの実験２５は負極被膜形成物質としてＦＥＣのみを使用した比較例、実験２６はＦＥＣとＬｉＢＦ４を用いた実施例である。
実験２７は負極被膜を形成する物質としてＮＥＣとＬｉＢＦ４を用いた実施例であり、実験２８は負極被膜を形成する物質としてＣＥＣとＬｉＢＦ４を用いた実施例である。
Further, supplementary explanation of the notation of Table 1 will be described. Experiments 1 to 3 are comparative examples using EC, GBL, and FEC as materials for forming a negative electrode film, and Experiments 4 to 12 are FEC as materials for forming a negative electrode film. Examples and Reference Examples using LiBF 4 and Experiments 13 to 14 are similar comparative examples, and Experiments 15 to 22 are similar examples.
Experiment 12 was conducted to verify the effect on the polymer gel electrolyte in the examples. At this time, lauroyl peroxide was added as an initiator at 1% by mass relative to the gel-forming compound content in order to form a polymer gel electrolyte.
Experiments 13 and 14 were performed as comparative examples in order to verify the effect of the electrolyte on the dielectric constant.
Experiments 23 and 24 are comparative examples using FEC and BETI as substances forming the negative electrode film. Experiments 25 and 26 use BETI as the electrolytic salt, of which Experiment 25 is a comparative example using only FEC as a negative electrode film-forming substance, and Experiment 26 is an example using FEC and LiBF 4 .
Experiment 27 is an example using NEC and LiBF 4 as materials for forming the negative electrode film, and Experiment 28 is an example using CEC and LiBF 4 as materials for forming the negative electrode film.
次に、コバルト酸リチウム（ＬｉＣｏＯ２）からなる正極活物質に対して、カーボンブラックを混合して混合物とした。またポリフッ化ビニリデンが溶解されているＮ−メチルピロリドン溶液を用意した。そしてＮ−メチルピロリドン溶液に上記の混合物を混合してスラリーとし、このスラリーをドクターブレード法によりアルミニウム箔に塗布した。スラリーの塗布した後に乾燥を行い、更に短冊状に裁断することで、集電体であるアルミニウム箔上に正極が形成されてなる正極電極を用意した。 Next, carbon black was mixed with the positive electrode active material made of lithium cobaltate (LiCoO 2 ) to obtain a mixture. An N-methylpyrrolidone solution in which polyvinylidene fluoride was dissolved was prepared. And said mixture was mixed with N-methylpyrrolidone solution to make a slurry, and this slurry was applied to an aluminum foil by a doctor blade method. After applying the slurry, it was dried and further cut into strips to prepare a positive electrode in which a positive electrode was formed on an aluminum foil as a current collector.
次に、ポリフッ化ビニリデンが溶解されているＮ−メチルピロリドン溶液に、人造黒鉛を混合してスラリーとし、このスラリーをドクターブレード法により銅箔に塗布した。スラリーの塗布した後に乾燥を行い、更に短冊状に裁断することで、集電体である銅箔上に負極が形成されてなる負極電極を用意した。 Next, artificial graphite was mixed with an N-methylpyrrolidone solution in which polyvinylidene fluoride was dissolved to form a slurry, and this slurry was applied to a copper foil by a doctor blade method. After applying the slurry, it was dried and further cut into strips to prepare a negative electrode having a negative electrode formed on a copper foil as a current collector.
正極電極と負極電極の間にポリプロピレン製多孔質セパレータを挟み、更にこれらを渦巻状に巻回することにより素電池を作製し、これをアルミラミネート製の電池容器に挿入した。そして、素電池を挿入した電池容器に、上記表１に示す実験１〜２８の電解質を所定量注液した。そして、注液後に電池容器を封止し、２４時間放置することにより、実験１〜２８のリチウム二次電池を製造した。なお、実験１２の電池については、更に７０℃４時間の加熱を行い、ゲルポリマー電解質を形成させた。 A unit cell was prepared by sandwiching a porous separator made of polypropylene between the positive electrode and the negative electrode, and further winding them in a spiral shape, and this was inserted into a battery container made of aluminum laminate. Then, a predetermined amount of the electrolyte of Experiments 1 to 28 shown in Table 1 was injected into the battery container into which the unit cell was inserted. Then, after the injection, the battery container was sealed and allowed to stand for 24 hours, whereby lithium secondary batteries of Experiments 1 to 28 were manufactured. The battery of Experiment 12 was further heated at 70 ° C. for 4 hours to form a gel polymer electrolyte.
尚、実験に使用した電池のサイズは、厚さ３．８ｍｍ、幅３５ｍｍ、高さ６２ｍｍのアルミラミネート外装を用い、設計容量は８００ｍＡｈであった。 The size of the battery used in the experiment was an aluminum laminate exterior with a thickness of 3.8 mm, a width of 35 mm, and a height of 62 mm, and the design capacity was 800 mAh.
（電池特性評価方法）
実験１乃至２６のリチウム二次電池について、寿命特性、過充電特性、高温放置特性及び高温回復容量を測定して表２に記載した。各々の電池特性の評価は次のように実施した。
寿命特性は実験１乃至２６のリチウム二次電池について、充放電を繰り返し行うことにより評価した。尚、充電条件は定電流−定電圧充電とし、１Ｃの電流で電圧が４．２Ｖに達するまで定電流充電したあとに、４．２Ｖで２時間の定電圧充電する条件とした。また放電条件は定電流放電とし、１Ｃで電圧が３．０Ｖに達するまで放電する条件とした。１００回後の容量残存率を表２に示す。尚、１００回後の容量残存率とは、１回目充放電時の放電容量に対する１００回目充放電時の放電容量の割合である。
(Battery characteristics evaluation method)
The lithium secondary batteries of Experiments 1 to 26 were measured for life characteristics, overcharge characteristics, high temperature storage characteristics, and high temperature recovery capacities, and are listed in Table 2. Each battery characteristic was evaluated as follows.
The lifetime characteristics were evaluated by repeatedly charging and discharging the lithium secondary batteries of Experiments 1 to 26. The charging conditions were constant current-constant voltage charging, and constant current charging was performed until the voltage reached 4.2 V at a current of 1 C, and then constant voltage charging was performed at 4.2 V for 2 hours. The discharge condition was constant current discharge, and the discharge was performed until the voltage reached 3.0 V at 1C. The capacity remaining rate after 100 times is shown in Table 2. The capacity remaining rate after 100 times is the ratio of the discharge capacity at the 100th charge / discharge to the discharge capacity at the first charge / discharge.
充電状態での過充電特性は４．２Ｖまで０．５Ｃ定電流充電した後に、４．２Ｖで２時間の定電圧充電を実施した後、３時間常温放置後、２Ａの定電流で１２Ｖまで５時間過充電を実施した。 The overcharge characteristics in the charged state are as follows: 0.5C constant current charging to 4.2V, 2V constant voltage charging at 4.2V, 3 hours standing at room temperature, 2A constant current to 12V 5 Time overcharge was performed.
放電状態での過充電特性は３．０Ｖまで０．５Ｃ定電流放電した後に、３時間常温放置後、２Ａの定電流で１２Ｖまで５時間過充電を実施した。 The overcharge characteristics in the discharged state were as follows: 0.5C constant current discharge to 3.0V, left at room temperature for 3 hours, and then overcharge to 12V at a constant current of 2A for 5 hours.
高温放置特性は９０℃の恒温オーブンに４時間放置した後に、温度が下げる前に電池の厚さを測定して高温放置前の厚さに対する厚さ増加率を得た。また、３時間常温放置後、０．５Ｃの定電流で３Ｖまで放電させた後、４．２Ｖまで０．５Ｃで充電、再び３．０Ｖまで０．５Ｃで放電を実施した後、放電容量を比較して高温回復率を測定した。高温回復率は高温貯蔵前の放電容量に対する高温貯蔵後の放電容量の割合である。 The high temperature storage characteristics were determined by leaving the battery in a constant temperature oven at 90 ° C. for 4 hours and then measuring the thickness of the battery before the temperature decreased to obtain the rate of increase in thickness relative to the thickness before the high temperature storage. Also, after standing at room temperature for 3 hours, discharged to 3V with a constant current of 0.5C, charged to 4.2V at 0.5C, discharged again to 3.0V at 0.5C, and then discharged capacity The high temperature recovery rate was measured in comparison. The high temperature recovery rate is the ratio of the discharge capacity after high temperature storage to the discharge capacity before high temperature storage.
表２の実験１乃至４のリチウム二次電池において、ＥＣによって負極被膜を形成させた実験１の場合には寿命特性は優れているが、過充電実験では充電状態での過充電条件でも爆発が起こっていることが分かる。これは表３に示されているように燃焼熱が高く引火点が低いＤＥＣを過剰に使用したので過充電時に発生する熱量によって爆発の段階まで到達することが分かる In the lithium secondary batteries of Experiments 1 to 4 in Table 2, the life characteristics are excellent in Experiment 1 in which the negative electrode film is formed by EC, but in the overcharge experiment, explosion occurs even in the overcharge condition in the charged state. You can see what is happening. As shown in Table 3, because DEC with high combustion heat and low flash point was used excessively, it can be seen that the stage of explosion is reached by the amount of heat generated during overcharge.
実験２及び３の場合には用いられた電解液が引火点と燃焼熱の観点で実験１の条件よりは安定した高燃焼熱低引火点の溶媒を８０体積％使用したので、充電状態での過充電条件では爆発が起こっていないことが分かる。
しかし、耐久性のある負極被膜形成剤が添加された実験４の条件でのみ放電状態の過充電条件を満足させることができる条件であることが分かる。これは本発明で提案された電解質組成によって負極被膜を形成する場合に一層安全な電池の製作が可能であることを示すといえる。
In the case of
However, it can be seen that the overcharge condition in the discharged state can be satisfied only under the condition of Experiment 4 in which the durable negative electrode film forming agent was added. This indicates that a safer battery can be produced when the negative electrode film is formed by the electrolyte composition proposed in the present invention.
高温貯蔵特性に対する考察で、同一な電解質組成を用いた実験２ないしは４の比較において、被膜の耐久性が弱い実験２と実験３の場合に負極被膜の破壊により電解液分解によるガス発生によって電池の厚さが増加し、それに伴う電池の内部抵抗の増加が高温貯蔵後の回復容量の低下に繋がっていることが分かる。一方、耐久性負極被膜形成剤が添加された実験４の場合には、高温放置中のガス発生が抑制されることによって厚さ増加も抑制され、高温貯蔵後の容量回復率も９５％以上の良好な結果が出ていることが分かる。
In the comparison of
実験４乃至実験９の結果は、耐久性のある負極被膜形成剤を添加し、エチレンカーボネートを０乃至３０体積％の範囲内で添加し、γ−ブチロラクトンを５０〜１００体積％の範囲内で添加し、ジエチレンカーボネートを０乃至２０体積％の範囲内で添加して組成された電解質を含む電池に対する性能評価を実施したものである。その結果、寿命、過充電、高温特性面でほとんど有意差が無いことが分かる。これは電解質の引火点と燃焼熱の観点からより安定した組成に維持されたため過充電の条件で有利な利点を有し、また、耐久性のある負極被膜形成剤を添加したため高温特性面でも優れた結果を示すようになったと考えられる。また、寿命特性においては各電解液系の混合溶媒に対する誘電率がリチウムイオンを解離するに十分な程度の値を持っているため、寿命特性に対する急激な劣化は発生しないと判断される。
The results of Experiment 4 to
実験１０と実験１１は不燃性溶媒であるＦＥを添加した電解質に対する性能確認の結果である。同様に、本発明の実験条件の範囲内ではＦＥを添加しない電解質に比べて別段有意差なく優れた性能を見せているが、もう少し危険な安全性実験条件では不燃性溶媒を入れた電池システムが一層有利であるように考えられる。
実験１２は実験９の条件にゲルポリマー電解質を導入した電解質である。安全性面では有意差なく評価されたが、電解質をゲルポリマー電池化することにより寿命特性と高温貯蔵特性で多少有利な特性を示しているのが確認された。
Experiment 12 is an electrolyte in which a gel polymer electrolyte is introduced under the conditions of
実験１３は比較例として耐久性のある負極被膜形成剤を使用し、燃焼熱が高く引火点が低い可燃性溶媒であるジエチルカーボネートを９０体積％以上使用した時の実験結果である。寿命特性面では他の実施例に比べて性能が多く劣っていることが分かる。これは用いられた電解液の誘電率が非常に低いため、充放電が進度に応じてリチウムイオンを解離及び移動させて電池性能を実現させるには不十分なためであると判断される。また、過充電特性でも可燃性溶媒を使用したため非常に脆弱な特性を示していることが分かる。高温特性面でも、負極被膜の組成は耐熱性があっても電解液自体の沸点が低いため、電池の膨れ（ｓｗｅｌｌｉｎｇ）を誘発させ、それによる正極と負極との間の距離増加に伴う抵抗の増加によって回復容量の減少を招いたと判断される。 Experiment 13 is an experimental result when using a durable negative electrode film-forming agent as a comparative example and using 90% by volume or more of diethyl carbonate which is a combustible solvent having a high combustion heat and a low flash point. It can be seen that the life characteristics are much inferior to those of the other examples. It is judged that this is because the dielectric constant of the electrolyte used is very low, and charging / discharging is insufficient to dissociate and move lithium ions according to the progress to realize battery performance. It can also be seen that the overcharge characteristics are very fragile due to the use of a flammable solvent. Even in terms of high temperature characteristics, the composition of the negative electrode coating has a low boiling point of the electrolyte itself even if it has heat resistance, so that it induces battery swelling, resulting in an increase in resistance due to an increase in the distance between the positive electrode and the negative electrode. It is judged that the increase resulted in a decrease in recovery capacity.
負極被膜形成剤であるＦＥＣの含量を調節して実施した実験６、実験１５乃至実験１７の結果でＦＥＣの含量が増加するほど、寿命性能には有意差がないが、過充電及び高温特性では順次に不利に作用していることが確認された。特に放電状態での過充電実験で爆発でない破裂が現れたことは用いられたＦＥＣの分解による過剰のガス発生によって破裂が起こったと判断される。また、高温貯蔵特性面でも不利に作用していることが分かる。 As the FEC content increases in the results of Experiment 6 and Experiments 15 to 17 performed by adjusting the content of FEC as a negative electrode film forming agent, there is no significant difference in life performance. It has been confirmed that it is acting adversely in turn. In particular, the appearance of a non-explosive rupture in an overcharge experiment in a discharged state is considered to have occurred due to excessive gas generation due to decomposition of the used FEC. Moreover, it turns out that it is acting disadvantageously also in the high temperature storage characteristic surface.
実験６と実験１８乃至実験２２の実験結果によると、負極被膜形成剤であるＬｉＢＦ４の含量による特性比較で、ＬｉＢＦ４の含量が増加するほど寿命特性が劣化していることが分かる。これはＬｉＢＦ４の含量が増加するほど負極の被膜に対する緻密度が増加し、それによって被膜での抵抗が増加したためであると判断される。 Experimental results of Experiment 6 and Experiment 18 to experiment 22, the characteristic comparison by the content of LiBF 4 is a negative electrode film-forming agent, it can be seen that the life characteristics as the content of LiBF 4 increases is deteriorated. This is considered to be because the density of the negative electrode film increases as the LiBF 4 content increases, thereby increasing the resistance of the film.
実験２３及び実験２４の結果によると、負極被膜形成剤であるＬｉＢＦ４の代りに体積がさらに大きいＢＥＴＩを使用した場合には本発明の耐久性のある被膜では形成されていない実験３とほとんど同じ特性を示していることが分かる。
According to the results of Experiment 23 and Experiment 24, when BETI having a larger volume is used instead of LiBF 4 which is the negative electrode film forming agent, it is almost the same as
実験２５及び実験２６の結果によると、基本電解質塩として使用した１．３ＭのＬｉＰＦ６の代りに１．３ＭのＢＥＴＩを使用した電解質に対して本発明で提案されている負極被膜形成剤を適用した結果、寿命容量に対する減少はあったが、ほとんど類似した結果が出ていることが分かる。これはＢＥＴＩのイオン伝導特性がＬｉＰＦ６より低いため容量減少との特性を示したが、耐久性のある負極被膜形成剤による効果であると考えられる。
また、負極被膜形成用添加剤として、ＦＥＣの代わりに、各々ＮＥＣ、ＣＥＣを使用した実験２７及び２８も実験４と類似した特性を示した。
According to the results of Experiment 25 and Experiment 26, the negative electrode film forming agent proposed in the present invention was applied to an electrolyte using 1.3 M BETI instead of 1.3 M LiPF 6 used as the basic electrolyte salt. As a result, although there was a decrease in the life capacity, it can be seen that almost similar results are obtained. This indicates that the capacity of the BETI ion conduction is lower than that of LiPF 6 and thus the capacity is reduced. However, this is considered to be an effect of a durable negative electrode film forming agent.
In addition, Experiments 27 and 28 using NEC and CEC, respectively, instead of FEC as an additive for forming a negative electrode film showed characteristics similar to Experiment 4.
（クーロン効率のプロファイル）
図１〜図２に、リチウム二次電池の初充電時における充電電圧に対するクーロン効率のプロファイルを示す。図１には実験１ないしは４のプロファイルを示す。また図２には実験１７乃至２１に該当する事項であって、ＬｉＢＦ４の含量増加によるプロファイルを示す。
(Coulomb efficiency profile)
1 to 2 show a profile of coulomb efficiency with respect to a charging voltage at the time of initial charging of a lithium secondary battery. FIG. 1 shows the profiles of Experiments 1 to 4. FIG. 2 shows a profile corresponding to Experiments 17 to 21 and an increase in LiBF 4 content.
図１に示すように、電解質にＬｉＢＦ４が０．０３ｍｏｌ／Ｌ添加された実験４の電解質は３Ｖ付近にピークが観察される。このピークはＬｉＢＦ４が負極表面の皮膜に取り込まれる際の何らかの反応により現れたものと考えられる。これに比して、ＬｉＢＦ４が添加されていない実験１乃至３の電解質は３ボルトのピークを示さない。
また図２に示すように、電解質にＬｉＢＦ４が０．１、０．５、１ｍｏｌ／Ｌ添加された実験２０、２１、２２の電解質は３Ｖ前後にピークが観察され、ＬｉＢＦ４の添加量が増えるに従ってピーク強度が大きくなっている。このことから、図１及び図２において観察されるピークはＬｉＢＦ４によるものであると推定される。
As shown in FIG. 1, a peak is observed in the vicinity of 3V in the electrolyte of Experiment 4 in which LiBF 4 was added to the electrolyte in an amount of 0.03 mol / L. This peak is considered to have appeared due to some reaction when LiBF 4 is taken into the film on the negative electrode surface. In contrast, the electrolytes of Experiments 1 to 3 with no added LiBF 4 do not show a 3 volt peak.
In addition, as shown in FIG. 2, peaks in the electrolytes of Experiments 20, 21, and 22 in which LiBF 4 was added to the electrolyte at 0.1, 0.5, and 1 mol / L were observed at about 3 V, and the amount of LiBF 4 added was The peak intensity increases as it increases. From this, it is estimated that the peak observed in FIGS. 1 and 2 is due to LiBF 4 .
Claims (29)
前記環状カーボネートの添加量が非水性有機溶媒に対して０乃至３０体積％の範囲内であり、前記γ−ブチロラクトンの添加量が非水性有機溶媒に対して５０乃至１００体積％の範囲内であり、前記エステル化合物の添加量が電解質に対して３質量％以上５質量％以下の範囲内であり、前記ＬｉＢＦ４の添加量が電解質に対して０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲内であり、
前記環状カーボネートはエチレンカーボネート、プロピレンカーボネート及びこれらの混合物からなる群より選択され、
前記エステル化合物が下記の［化１］に示されるエチレンカーボネート誘導体であることを特徴とするリチウム二次電池用電解質：
The addition amount of the cyclic carbonate is in the range of 0 to 30% by volume with respect to the non-aqueous organic solvent, and the addition amount of the γ-butyrolactone is in the range of 50 to 100% by volume with respect to the non-aqueous organic solvent. The amount of the ester compound added is in the range of 3% by mass to 5% by mass relative to the electrolyte, and the amount of the LiBF 4 added is in the range of 0.001 mol / L to 1 mol / L to the electrolyte. And
The cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate and mixtures thereof;
An electrolyte for a lithium secondary battery, wherein the ester compound is an ethylene carbonate derivative represented by the following [Chemical Formula 1]:
リチウムの吸蔵、放出が可能な正極と、
環状カーボネート及びγ−ブチロラクトンを含む非水性有機溶媒、ハロゲン基、シアノ基（ＣＮ）及びニトロ基（ＮＯ２）からなる群より選択される電子吸引基を有するエステル化合物並びに少なくともＬｉＢＦ４を含む２つ以上の塩を含む電解質とを備え、
前記環状カーボネートの添加量が非水性有機溶媒に対して０乃至３０体積％の範囲内であり、前記γ−ブチロラクトンの添加量が非水性有機溶媒に対して５０乃至１００体積％の範囲内であり、前記エステル化合物の添加量が電解質に対して３質量％以上５質量％以下の範囲内であり、前記ＬｉＢＦ４の添加量が電解質に対して０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下の範囲内であり、
前記環状カーボネートはエチレンカーボネート、プロピレンカーボネート及びこれらの混合物からなる群より選択され、
前記エステル化合物が下記の［化２］に示されるエチレンカーボネート誘導体であることを特徴とするリチウム二次電池：
A positive electrode capable of inserting and extracting lithium;
Non-aqueous organic solvent containing a cyclic carbonate and γ-butyrolactone, an ester compound having an electron withdrawing group selected from the group consisting of a halogen group, a cyano group (CN) and a nitro group (NO 2 ), and at least two containing LiBF 4 An electrolyte containing the above salt,
The addition amount of the cyclic carbonate is in the range of 0 to 30% by volume with respect to the non-aqueous organic solvent, and the addition amount of the γ-butyrolactone is in the range of 50 to 100% by volume with respect to the non-aqueous organic solvent. The amount of the ester compound added is in the range of 3% by mass to 5% by mass relative to the electrolyte, and the amount of the LiBF 4 added is in the range of 0.001 mol / L to 1 mol / L to the electrolyte. And
The cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate and mixtures thereof;
The lithium secondary battery, wherein the ester compound is an ethylene carbonate derivative represented by the following [Chemical Formula 2]:
ＬｉｘＭｎ１−ｙＭｙＡ２ （１）
ＬｉｘＭｎ１−ｙＭｙＯ２−ｚＸｚ （２）
ＬｉｘＭｎ２Ｏ４−ｚＸｚ （３）
ＬｉｘＭｎ２−ｙＭｙＭ´ｚＡ４ （４）
ＬｉｘＣｏ１−ｙＭｙＡ２ （５）
ＬｉｘＣｏ１−ｙＭｙＯ２−ｚＸｚ （６）
ＬｉｘＮｉ１−ｙＭｙＡ２ （７）
ＬｉｘＮｉ１−ｙＭｙＯ２−ｚＸｚ （８）
ＬｉｘＮｉ１−ｙＣｏｙＯ２−ｚＸｚ （９）
ＬｉｘＮｉ１−ｙ−ｚＣｏｙＭｚＡα （１０）
ＬｉｘＮｉ１−ｙ−ｚＣｏｙＭｚＯ２−αＸα （１１）
ＬｉｘＮｉ１−ｙ−ｚＭｎｙＭｚＡα （１２）
ＬｉｘＮｉ１−ｙ−ｚＭｎｙＭｚＯ２−αＸα （１３）
ＬｉｘＭｎ２−ｙ−ｚＭｙＭ´ｚＡ４ （１４）
ただし、前記式において、組成比を示すｘ、ｙ、ｚ、αは、０．９０≦ｘ≦１．１、０≦ｙ≦０．５、０≦ｚ≦０．５、０≦α＜２であり、ＭとＭ´は同一であるか互いに異なる元素であってＭｇ、Ａｌ、Ｃｏ、Ｋ、Ｎａ、Ｃａ、Ｓｉ、Ｔｉ、Ｓｎ、Ｖ、Ｇｅ、Ｇａ、Ｂ、Ａｓ、Ｚｒ、Ｎｉ、Ｍｎ、Ｃｒ、Ｆｅ、Ｓｒ、Ｖ及び希土類元素からなる群より選択され、ＡはＯであり、ＸはＦである。 The lithium secondary battery according to any one of claims 13 to 24, wherein the positive electrode includes a lithium compound selected from the group consisting of the following (1) to (14) as a positive electrode active material. .
Li x Mn 1- y My A 2 (1)
Li x Mn 1-y M y O 2-z X z (2)
Li x Mn 2 O 4-z X z (3)
Li x Mn 2-y M y M'z A 4 (4)
Li x Co 1- y My A 2 (5)
Li x Co 1-y M y O 2-z X z (6)
Li x Ni 1- y My A 2 (7)
Li x Ni 1-y M y O 2-z X z (8)
Li x Ni 1-y Co y O 2-z X z (9)
Li x Ni 1-yz Co y M z A α (10)
Li x Ni 1-yz Co y M z O 2-α X α (11)
Li x Ni 1-y-z Mn y M z A α (12)
Li x Ni 1-y-z Mn y M z O 2-α X α (13)
Li x Mn 2-yz M y M ′ z A 4 (14)
However, in the above formula, x, y, z, and α indicating the composition ratio are 0.90 ≦ x ≦ 1.1, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 0.5, and 0 ≦ α <2. M and M ′ are the same or different elements, and Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Ni, Selected from the group consisting of Mn, Cr, Fe, Sr, V and rare earth elements, A is O and X is F.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003274875A JP4671589B2 (en) | 2003-07-15 | 2003-07-15 | Electrolyte for lithium secondary battery and lithium secondary battery |
| KR1020030086809A KR100589321B1 (en) | 2003-07-15 | 2003-12-02 | An electrolyte for lithium secondary battery and a lithium secondary battery comprising the same |
| US10/891,233 US7491471B2 (en) | 2003-07-15 | 2004-07-15 | Electrolyte for lithium secondary battery and lithium secondary battery comprising same |
| EP04090277.7A EP1498979B1 (en) | 2003-07-15 | 2004-07-15 | Organic electrolyte for lithium secondary battery and lithium secondary battery comprising same |
| CNB2004100766657A CN100459273C (en) | 2003-07-15 | 2004-07-15 | Electrolyte for lithium secondary battery and lithium secondary battery comprising same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2003274875A JP4671589B2 (en) | 2003-07-15 | 2003-07-15 | Electrolyte for lithium secondary battery and lithium secondary battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005038722A JP2005038722A (en) | 2005-02-10 |
| JP4671589B2 true JP4671589B2 (en) | 2011-04-20 |
Family
ID=34211711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2003274875A Expired - Lifetime JP4671589B2 (en) | 2003-07-15 | 2003-07-15 | Electrolyte for lithium secondary battery and lithium secondary battery |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4671589B2 (en) |
| KR (1) | KR100589321B1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020230847A1 (en) | 2019-05-14 | 2020-11-19 | マツダ株式会社 | Lithium ion secondary battery |
Families Citing this family (48)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100709208B1 (en) | 2004-06-30 | 2007-04-19 | 삼성에스디아이 주식회사 | A lithium secondary battery |
| KR100709207B1 (en) | 2004-06-30 | 2007-04-18 | 삼성에스디아이 주식회사 | A lithium secondary battery |
| KR100859999B1 (en) * | 2004-12-22 | 2008-09-25 | 주식회사 엘지화학 | Cyclic Cyano Carbonate Compound, and Non-aqueous Electrolyte System Containing the Same as an Additive, and Lithium Secondary Battery of Improved Safety Having the Same |
| TW200642135A (en) * | 2005-02-25 | 2006-12-01 | Lg Chemical Ltd | Lithium secondary battery with high performance |
| JP4784133B2 (en) * | 2005-04-13 | 2011-10-05 | ソニー株式会社 | Secondary battery and battery |
| KR100759377B1 (en) | 2005-04-21 | 2007-09-19 | 삼성에스디아이 주식회사 | Rechargeable lithium battery |
| KR100833041B1 (en) * | 2005-05-03 | 2008-05-27 | 주식회사 엘지화학 | Nonaqueous electrolyte for improving performance and lithium secondary battery comprising the same |
| JP4839673B2 (en) * | 2005-05-12 | 2011-12-21 | ソニー株式会社 | Secondary battery electrolyte and secondary battery |
| KR100770081B1 (en) | 2005-07-06 | 2007-10-24 | 삼성에스디아이 주식회사 | Polymer electrolyte for lithium secondary battery and a lithium secondary battery comprising the same |
| KR100684733B1 (en) * | 2005-07-07 | 2007-02-20 | 삼성에스디아이 주식회사 | Lithium secondary battery |
| KR100726889B1 (en) | 2005-07-22 | 2007-06-14 | 한국과학기술원 | Nonaqueous electrolyte for lithium battery and lithium secondary battery comprising the electrolyte |
| JP2007042329A (en) * | 2005-08-01 | 2007-02-15 | Mitsui Chemicals Inc | Lithium secondary battery |
| KR100770082B1 (en) | 2005-08-18 | 2007-10-24 | 삼성에스디아이 주식회사 | Electrolyte for lithium rechargeable battery and lithium rechargeable battery comprising it |
| US8715852B2 (en) * | 2005-08-18 | 2014-05-06 | Samsung Sdi Co., Ltd. | Electrolyte for lithium secondary battery and lithium secondary battery including the same |
| JP2007123242A (en) * | 2005-09-28 | 2007-05-17 | Sanyo Electric Co Ltd | Nonaqueous electrolyte secondary battery |
| KR100706714B1 (en) * | 2005-11-24 | 2007-04-13 | 비나텍주식회사 | Hybrid battery |
| JP5239119B2 (en) * | 2005-12-26 | 2013-07-17 | セントラル硝子株式会社 | Non-aqueous electrolyte battery electrolyte and non-aqueous electrolyte battery |
| KR100709218B1 (en) * | 2005-12-30 | 2007-04-18 | 삼성에스디아이 주식회사 | Lithium secondary battery |
| JP4306697B2 (en) | 2006-06-16 | 2009-08-05 | ソニー株式会社 | Secondary battery |
| JP5109381B2 (en) * | 2006-08-14 | 2012-12-26 | ソニー株式会社 | Nonaqueous electrolyte secondary battery |
| JP5318356B2 (en) | 2007-02-23 | 2013-10-16 | 三洋電機株式会社 | Nonaqueous electrolyte secondary battery |
| US9048508B2 (en) | 2007-04-20 | 2015-06-02 | Mitsubishi Chemical Corporation | Nonaqueous electrolytes and nonaqueous-electrolyte secondary batteries employing the same |
| JP5374828B2 (en) * | 2007-04-20 | 2013-12-25 | 三菱化学株式会社 | Non-aqueous electrolyte for secondary battery and non-aqueous electrolyte secondary battery using the same |
| EP2158635B1 (en) | 2007-06-11 | 2013-07-31 | LG Chem, Ltd. | Non-aqueous electrolyte and secondary battery comprising the same |
| JP4715848B2 (en) * | 2008-01-09 | 2011-07-06 | ソニー株式会社 | battery |
| JP5401836B2 (en) * | 2008-01-29 | 2014-01-29 | ダイキン工業株式会社 | Solvent for dissolving electrolyte salt of lithium secondary battery |
| JP4655118B2 (en) * | 2008-01-31 | 2011-03-23 | ソニー株式会社 | Non-aqueous electrolyte battery and non-aqueous electrolyte composition |
| CN102498590A (en) | 2009-08-19 | 2012-06-13 | 三菱化学株式会社 | Separator for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery |
| KR101640937B1 (en) | 2009-11-13 | 2016-07-20 | 삼성에스디아이 주식회사 | Rechargeable lithium battery |
| JP2011198637A (en) * | 2010-03-19 | 2011-10-06 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary battery module |
| US8481212B2 (en) * | 2010-09-14 | 2013-07-09 | Hitachi Maxell, Ltd. | Non-aqueous secondary battery |
| US9005823B2 (en) | 2011-05-04 | 2015-04-14 | Samsung Sdi Co., Ltd. | Electrolyte for rechargeable lithium battery and rechargeable lithium battery including the same |
| JP5848545B2 (en) * | 2011-08-08 | 2016-01-27 | 三星エスディアイ株式会社Ｓａｍｓｕｎｇ ＳＤＩ Ｃｏ．，Ｌｔｄ． | Secondary battery separator layer and secondary battery |
| CN103875116B (en) * | 2012-03-27 | 2016-08-17 | 旭硝子株式会社 | Non-aqueous electrolyte for secondary battery and lithium rechargeable battery |
| KR20140066050A (en) * | 2012-11-22 | 2014-05-30 | 주식회사 엘지화학 | Electrolyte solution for lithium secondary battery and lithium secondary battery comprising the same |
| JP2014203748A (en) * | 2013-04-08 | 2014-10-27 | 株式会社日本触媒 | Nonaqueous electrolytic solution for lithium ion secondary batteries, and lithium ion secondary battery having the same |
| JP6428631B2 (en) * | 2013-09-24 | 2018-11-28 | Ａｇｃ株式会社 | Nonaqueous electrolyte for secondary battery and lithium ion secondary battery |
| JPWO2015046171A1 (en) * | 2013-09-24 | 2017-03-09 | 旭硝子株式会社 | Nonaqueous electrolyte for secondary battery and lithium ion secondary battery |
| WO2015046173A1 (en) * | 2013-09-24 | 2015-04-02 | 旭硝子株式会社 | Lithium ion secondary battery |
| JP6396105B2 (en) * | 2013-09-30 | 2018-09-26 | パナソニック株式会社 | Nonaqueous electrolyte secondary battery |
| JP5910652B2 (en) * | 2014-03-17 | 2016-04-27 | ソニー株式会社 | Lithium ion secondary battery |
| CN107112583A (en) * | 2014-10-29 | 2017-08-29 | 日立麦克赛尔株式会社 | Lithium rechargeable battery |
| JP6724271B2 (en) * | 2015-09-11 | 2020-07-15 | 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． | Positive electrode active material particles, lithium ion secondary battery using the same, and method for producing positive electrode active material particles |
| WO2018011675A1 (en) | 2016-07-13 | 2018-01-18 | Semiconductor Energy Laboratory Co., Ltd. | Graphene compound, method for forming graphene compound, and power storage device |
| US10707524B2 (en) | 2016-10-19 | 2020-07-07 | Semiconductor Energy Laboratory Co., Ltd. | Graphene compound and manufacturing method thereof, electrolyte, and power storage device |
| KR20200000446A (en) | 2017-05-19 | 2020-01-02 | 시온 파워 코퍼레이션 | Passivating agents for electrochemical cells |
| JP2020098739A (en) * | 2018-12-19 | 2020-06-25 | トヨタ自動車株式会社 | Nonaqueous electrolyte secondary battery |
| CN117384330B (en) * | 2023-12-12 | 2024-02-23 | 蓝固(淄博)新能源科技有限公司 | Preparation method of fluoro-1, 3-dioxolane heterocyclic compound, in-situ solid electrolyte, preparation method and application thereof |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0714148A1 (en) * | 1994-11-09 | 1996-05-29 | Furukawa Denchi Kabushiki Kaisha | A lithium secondary battery |
| JPH10154528A (en) * | 1996-11-22 | 1998-06-09 | Mitsui Chem Inc | Nonaqueous electrolyte and nonaqueous electrolyte secondary battery |
| JPH11185807A (en) * | 1997-12-17 | 1999-07-09 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JPH11195429A (en) * | 1998-01-05 | 1999-07-21 | Hitachi Ltd | Nonaqueous electrolytic solution secondary battery |
| JP2002298912A (en) * | 2001-03-29 | 2002-10-11 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary battery and electrolyte used for the same |
| JP2002329528A (en) * | 2001-03-01 | 2002-11-15 | Mitsui Chemicals Inc | Nonaqueous electrolyte, secondary battery using it and additive for electrolyte |
| JP2002352852A (en) * | 2001-05-23 | 2002-12-06 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary cell |
| JP2003086247A (en) * | 2001-09-13 | 2003-03-20 | Mitsubishi Chemicals Corp | Nonaqueous electrolytic solution secondary battery |
| JP2003086248A (en) * | 2001-09-14 | 2003-03-20 | Mitsubishi Chemicals Corp | Non-aqueous electrolytic solution secondary battery and electrolytic solution |
| JP2003123837A (en) * | 2001-10-15 | 2003-04-25 | Sony Corp | Electrolyte and battery |
-
2003
- 2003-07-15 JP JP2003274875A patent/JP4671589B2/en not_active Expired - Lifetime
- 2003-12-02 KR KR1020030086809A patent/KR100589321B1/en active IP Right Grant
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0714148A1 (en) * | 1994-11-09 | 1996-05-29 | Furukawa Denchi Kabushiki Kaisha | A lithium secondary battery |
| JPH10154528A (en) * | 1996-11-22 | 1998-06-09 | Mitsui Chem Inc | Nonaqueous electrolyte and nonaqueous electrolyte secondary battery |
| JPH11185807A (en) * | 1997-12-17 | 1999-07-09 | Sanyo Electric Co Ltd | Lithium secondary battery |
| JPH11195429A (en) * | 1998-01-05 | 1999-07-21 | Hitachi Ltd | Nonaqueous electrolytic solution secondary battery |
| JP2002329528A (en) * | 2001-03-01 | 2002-11-15 | Mitsui Chemicals Inc | Nonaqueous electrolyte, secondary battery using it and additive for electrolyte |
| JP2002298912A (en) * | 2001-03-29 | 2002-10-11 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary battery and electrolyte used for the same |
| JP2002352852A (en) * | 2001-05-23 | 2002-12-06 | Mitsubishi Chemicals Corp | Nonaqueous electrolyte secondary cell |
| JP2003086247A (en) * | 2001-09-13 | 2003-03-20 | Mitsubishi Chemicals Corp | Nonaqueous electrolytic solution secondary battery |
| JP2003086248A (en) * | 2001-09-14 | 2003-03-20 | Mitsubishi Chemicals Corp | Non-aqueous electrolytic solution secondary battery and electrolytic solution |
| JP2003123837A (en) * | 2001-10-15 | 2003-04-25 | Sony Corp | Electrolyte and battery |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020230847A1 (en) | 2019-05-14 | 2020-11-19 | マツダ株式会社 | Lithium ion secondary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20050008446A (en) | 2005-01-21 |
| JP2005038722A (en) | 2005-02-10 |
| KR100589321B1 (en) | 2006-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4671589B2 (en) | Electrolyte for lithium secondary battery and lithium secondary battery | |
| US7491471B2 (en) | Electrolyte for lithium secondary battery and lithium secondary battery comprising same | |
| JP5203990B2 (en) | Lithium secondary battery | |
| CN100583538C (en) | Electrolyte for lithium ion rechargeable battery and lithium ion rechargeable battery comprising the same | |
| KR100709838B1 (en) | Electrolyte for lithium rechargeable battery and a lithium rechargeable battery comprising it | |
| JP5298419B2 (en) | Secondary battery | |
| US8828604B2 (en) | Battery | |
| JP5262175B2 (en) | Negative electrode and secondary battery | |
| KR100573109B1 (en) | Organic electrolytic solution and lithium battery employing the same | |
| JP5109329B2 (en) | Secondary battery | |
| JP2009038018A (en) | Secondary battery | |
| JP2002260725A (en) | Nonaqueous electrolyte solution and lithium secondary battery using same | |
| JP2009105069A (en) | Electrolyte for lithium secondary battery, and lithium secondary battery containing same | |
| JP4765629B2 (en) | Non-aqueous electrolyte and lithium secondary battery | |
| JP2007335318A (en) | Nonaqueous electrolyte secondary battery | |
| KR100669322B1 (en) | A lithium secondary battery | |
| JP5261208B2 (en) | Nonaqueous electrolyte secondary battery | |
| WO2023081523A2 (en) | Bipolar lithium ion cathodes and cells and batteries containing lithium ion cathodes | |
| CA3233092A1 (en) | Non-aqueous electrolyte solution for lithium secondary battery, and lithium secondary battery including the same | |
| US20230187696A1 (en) | Non-Aqueous Electrolyte solution for Lithium Secondary Battery, and Lithium Secondary Battery Including the Same | |
| KR100751206B1 (en) | Additives for lithium secondarty battery with charge-cutoff voltages over 4.35 | |
| JP2004311115A (en) | Composition for electrolyte, polyelectrolyte, and battery using it |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20071106 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20080206 |
|
| A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20080212 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20080306 |
|
| A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20080311 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20080407 |
|
| A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20080410 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080501 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080924 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20081224 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20081226 |
|
| A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20090105 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100119 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100416 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20100518 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100917 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20101008 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20101220 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20110118 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4671589 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140128 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |