JP2009123715A - Lithium ion secondary battery - Google Patents

Lithium ion secondary battery Download PDF

Info

Publication number
JP2009123715A
JP2009123715A JP2009056404A JP2009056404A JP2009123715A JP 2009123715 A JP2009123715 A JP 2009123715A JP 2009056404 A JP2009056404 A JP 2009056404A JP 2009056404 A JP2009056404 A JP 2009056404A JP 2009123715 A JP2009123715 A JP 2009123715A
Authority
JP
Japan
Prior art keywords
active material
negative electrode
electrode active
lithium
positive electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2009056404A
Other languages
Japanese (ja)
Inventor
Hiromi Tamakoshi
博美 玉腰
Shinsuke Shibata
進介 柴田
Takeshi Azuma
東  彪
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Maxell Holdings Ltd
Original Assignee
Hitachi Maxell Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Maxell Ltd filed Critical Hitachi Maxell Ltd
Priority to JP2009056404A priority Critical patent/JP2009123715A/en
Publication of JP2009123715A publication Critical patent/JP2009123715A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Landscapes

  • Battery Electrode And Active Subsutance (AREA)
  • Cell Separators (AREA)
  • Secondary Cells (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To compose a high-reliability battery by improving cycle life, in a lithium ion secondary battery usable for application such as an electric power tool repeating charge/discharge at large current. <P>SOLUTION: The issue is solved by the lithium ion secondary battery in which a carbon material wherein an R value of a raman spectrum excited by an argon laser at a wavelength of 514.5 nm is 0.3-0.8, and a spacing d<SB>002</SB>of 002 planes is 0.34 nm or less is included as a negative electrode active material, the ratio of the carbon material in the negative electrode active material is 60 mass% or more; the density of a negative electrode mix layer is 1.4-1.6 g/cm<SP>3</SP>; at least one selected from a lithium-manganese oxide of a spinel structure, a lithium-nickel-cobalt composite oxide of a layer structure and a lithium composite compound of an olivine structure is included as a positive electrode active material; and a separator is a layered product containing a porous resin layer having a melting point of 120-140°C, and a porous resin layer having a melting point of 150°C or more. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、各種の電気機器に用いられるリチウムイオン二次電池に関する。   The present invention relates to a lithium ion secondary battery used for various electric devices.

非水電解質電池の一種であるリチウムイオン二次電池は、エネルギー密度が高いという特徴から、携帯電話やノート型パーソナルコンピューターなどの携帯機器の電源として広く用いられている。また、環境問題への配慮から、繰り返し充電できる二次電池の重要性が増大しており、携帯機器以外にも、自動車、電動工具、電気椅子や家庭用、業務用の電力貯蔵システムへの適用が検討されている。   A lithium ion secondary battery, which is a type of nonaqueous electrolyte battery, is widely used as a power source for portable devices such as mobile phones and notebook personal computers because of its high energy density. In addition, due to consideration of environmental issues, the importance of rechargeable secondary batteries is increasing, and in addition to portable devices, they can be applied to automobiles, power tools, electric chairs, household and commercial power storage systems. Is being considered.

上記のように電池に要求される特性は多岐に渡り、用途別に様々な対応が必要とされているが、電動工具など大電流での使用が前提となる用途では、大電流での使用時の高エネルギー密度化や充電時間の短縮化、すなわち、高負荷機器への適応のために入出力特性のさらなる向上が要求されている。   As described above, the characteristics required of batteries vary widely, and various measures are required depending on the application, but in applications that require use at high currents such as power tools, Further improvements in input / output characteristics are required for higher energy density and shorter charging time, that is, for adaptation to high load equipment.

このような要求に応えるため、電極活物質を大電流負荷に適するものとすることが検討されており、例えば、負極活物質として通常用いられる炭素材料を、黒鉛質粒子の表面に非晶質あるいは低結晶の炭素被覆層を有する複合材料とすることが提案されている(特許文献1〜4参照)。   In order to meet such demands, it has been studied to make an electrode active material suitable for a large current load. For example, a carbon material usually used as a negative electrode active material is made amorphous on the surface of graphite particles. It has been proposed to use a composite material having a low crystalline carbon coating layer (see Patent Documents 1 to 4).

特開平6−267531号公報JP-A-6-267531 特開平10−162858号公報Japanese Patent Laid-Open No. 10-162858 特開2002−42887号公報JP 2002-42887 A 特開2003−168429号公報JP 2003-168429 A

しかしながら、電動工具のように、充電および放電ともに大電流で行われる用途においては、電極での反応が不均一化しやすく、使用を繰り返すうちに、充放電時に生じる大きな発熱により電極内での局所的な劣化を生じやすく、携帯電話のようにさほど大電流を要求されない用途での使用の場合に比較して、特性低下が大きくなることが問題とされている。   However, in applications where both charging and discharging are performed with a large current, such as power tools, the reaction at the electrode tends to become non-uniform, and as the heat is repeatedly used, the large amount of heat generated during charging and discharging causes local localized in the electrode. Therefore, it is a problem that the deterioration of the characteristics becomes large as compared with the case where the mobile phone is used in an application where a large current is not required.

また、上記充放電時の発熱が、電極以外の電池部材にも影響を与え、問題を生じることも考えられる。通常、電動工具は数本の素電池をパック化して用いられるため、充放電により素電池内部の温度が上昇すると、パック内部に熱がこもり素電池の温度はさらに上昇する。その結果、セパレータの融点付近まで電池の内部温度が上昇し、セパレータが徐々に目詰まりを生じて大電流で充放電できなくなるという問題もあり、長期にわたり信頼性を維持することのできる電池が必要とされていた。   In addition, the heat generated during the charge / discharge may affect battery members other than the electrodes and cause problems. Usually, an electric power tool is used in a pack of several unit cells. Therefore, when the temperature inside the unit cell rises due to charging / discharging, heat is accumulated inside the pack, and the temperature of the unit cell further rises. As a result, the internal temperature of the battery rises to near the melting point of the separator, the separator gradually clogs, and it becomes impossible to charge and discharge with a large current, and a battery that can maintain reliability over a long period is necessary. It was said.

本発明は、上記課題を解決するためになされたもので、電動工具などの大電流で充放電を繰り返す用途に使用されるリチウムイオン二次電池において、サイクル寿命を向上させ、信頼性の高い電池を構成することを目的とする。   The present invention has been made in order to solve the above-described problems, and is a lithium ion secondary battery used for a purpose of repeatedly charging and discharging with a large current such as an electric tool, improving the cycle life and having a high reliability. It aims at constructing.

本発明のリチウムイオン二次電池は、負極活物質を含有する負極合剤層を有する負極、正極活物質を含有する正極合剤層を有する正極、セパレータおよび非水電解液を有するリチウムイオン二次電池であって、前記負極活物質として、波長514.5nmのアルゴンレーザーで励起させた時のラマンスペクトルのR値が0.3以上0.8以下であり、002面の面間隔d002が0.34nm以下である炭素材料を含有し、負極活物質における前記炭素材料の割合が60質量%以上であり、前記負極合剤層の密度が1.4〜1.6g/cmであり、前記正極活物質として、スピネル構造のリチウムマンガン酸化物、層状構造のリチウムニッケルコバルト複合酸化物およびオリビン構造のリチウム複合化合物より選択される少なくとも1種の化合物を含み、前記セパレータが、融点が120〜140℃の多孔質樹脂層と、融点が150℃以上の多孔質樹脂層との積層体であることを特徴とする。 The lithium ion secondary battery of the present invention includes a negative electrode having a negative electrode mixture layer containing a negative electrode active material, a positive electrode having a positive electrode mixture layer containing a positive electrode active material, a separator, and a lithium ion secondary having a non-aqueous electrolyte. In the battery, the R value of the Raman spectrum when excited by an argon laser having a wavelength of 514.5 nm as the negative electrode active material is 0.3 or more and 0.8 or less, and the interplanar spacing d 002 of 0 is 0. .34 nm or less of carbon material, the proportion of the carbon material in the negative electrode active material is 60% by mass or more, the density of the negative electrode mixture layer is 1.4 to 1.6 g / cm 3 , As the positive electrode active material, at least one selected from spinel structure lithium manganese oxide, layered structure lithium nickel cobalt composite oxide and olivine structure lithium composite compound They comprise a compound, wherein the separator is melting point and wherein the porous resin layer of 120 to 140 ° C., the melting point is a laminate of 0.99 ° C. or more porous resin layer.

大電流での充放電による特性劣化が少なく、安定した特性を長期にわたり維持するリチウムイオン二次電池を得ることができる。   It is possible to obtain a lithium ion secondary battery that has little deterioration in characteristics due to charging and discharging at a large current and maintains stable characteristics over a long period of time.

以下に、本発明のリチウムイオン二次電池の一例について説明する。   Below, an example of the lithium ion secondary battery of this invention is demonstrated.

負極は、銅箔などの集電体上に、負極活物質、導電助剤となる導電性粉末およびバインダーを含有する塗料を塗布し、乾燥させることにより負極合剤層を形成し、加圧成形することにより得られる。その際に、負極合剤層のエネルギー密度を高めるために、合剤層の密度が1.4g/cm以上となるようプレスを行えばよい。一方、合剤層への電解液の浸潤を均一化し、充放電における合剤層内部の反応を均一化するためには、合剤層の密度を1.6g/cm以下とすればよい。 The negative electrode is formed by applying a negative electrode active material, a conductive powder serving as a conductive additive and a binder containing a binder on a current collector such as a copper foil, and drying to form a negative electrode mixture layer, followed by pressure molding. Can be obtained. At that time, in order to increase the energy density of the negative electrode mixture layer, pressing may be performed so that the density of the mixture layer is 1.4 g / cm 3 or more. On the other hand, in order to make the infiltration of the electrolyte solution into the mixture layer uniform and make the reaction inside the mixture layer uniform in charge / discharge, the density of the mixture layer may be 1.6 g / cm 3 or less.

負極活物質は、波長514.5nmのアルゴンレーザーで励起させた時のラマンスペクトルのR値(1350cm−1付近のラマン強度I1350と1580cm−1付近のラマン強度I1580との比の値:I1350/I1580)が0.3以上0.8以下であり、002面の面間隔d002が0.34nm以下である炭素材料を用いる。このような炭素材料は容量が大きく、粒子表面でのリチウムイオンの挿入・脱離が容易で大電流での充放電に対応できると共に、電解液との反応が抑制され、充放電での発熱による電解液の分解を防ぐことができるので、大電流での充放電を繰り返しても優れた特性を長期間維持することができる。特に、BET比表面積が、1.5〜3.6m/gであれば、上記効果が発揮されやすくなるので好ましい。 The negative electrode active material, the ratio of the Raman intensity I 1580 near Raman intensity I 1350 and 1580 cm -1 in the vicinity of the Raman spectrum of the R value (1350 cm -1 when excited with an argon laser with a wavelength of 514.5nm values: I 1350 / I 1580 ) is 0.3 or more and 0.8 or less, and a carbon material having a 002 plane spacing d 002 of 0.34 nm or less is used. Such a carbon material has a large capacity, can easily insert and desorb lithium ions on the particle surface, can be used for charging / discharging with a large current, suppresses reaction with the electrolyte, and generates heat during charging / discharging. Since decomposition of the electrolytic solution can be prevented, excellent characteristics can be maintained for a long period of time even if charging and discharging with a large current are repeated. In particular, a BET specific surface area of 1.5 to 3.6 m 2 / g is preferable because the above-described effect is easily exhibited.

前記炭素材料は、これのみを負極活物質としてもよいが、負極合剤層の導電性向上や高容量化などのために、前記炭素材料と共に他の炭素材料あるいは他の材料を共存させてもよい。この場合は、前記炭素の効果を生じやすくするために、負極活物質全体における前記炭素材料の割合を60質量%以上とすればよい。   The carbon material may be used only as a negative electrode active material, but other carbon materials or other materials may coexist with the carbon material in order to improve the conductivity or increase the capacity of the negative electrode mixture layer. Good. In this case, in order to easily produce the carbon effect, the proportion of the carbon material in the entire negative electrode active material may be 60% by mass or more.

また、前記炭素材料と共に用いる他の炭素材料としては、R値が0.3未満の結晶性の高い炭素材料や、d002が0.34nmより大きい結晶性の低い炭素材料などを例示することができる。さらに、炭素材料以外の材料としては、SiやSnなどLiと合金化する元素およびこれら元素とCo、Ni、Mn、Tiなどの金属元素との合金、SiOなどLiと合金化する元素の酸化物、LiTi12やLiMnなどに代表されるスピネル構造を有する酸化物などを例示することができる。 Further, as the other carbon material for use with carbon materials, R value and a high carbon material of less than 0.3 crystallinity, that d 002 is illustrated like low carbon material 0.34nm greater crystallinity it can. Further, as materials other than carbon materials, elements such as Si and Sn that alloy with Li, alloys of these elements with metal elements such as Co, Ni, Mn, and Ti, oxides of elements that alloy with Li such as SiO, and the like Examples thereof include oxides having a spinel structure typified by Li 4 Ti 5 O 12 and LiMn 2 O 4 .

導電助剤は、負極合剤層の導電性向上などの目的で必要に応じて添加すればよく、導電助剤となる導電性粉末として、カーボンブラック、ケッチェンブラック、アセチレンブラック、繊維状炭素、黒鉛などの炭素粉末やニッケル粉末などの金属粉末を利用することができる。   The conductive auxiliary agent may be added as necessary for the purpose of improving the conductivity of the negative electrode mixture layer, and as a conductive powder to be a conductive auxiliary agent, carbon black, ketjen black, acetylene black, fibrous carbon, Carbon powder such as graphite and metal powder such as nickel powder can be used.

バインダーには、セルロースエーテル化合物やゴム系バインダー等が挙げられるが、これらに限定されるものではない。セルロースエーテル化合物の具体例としては、例えば、カルボキシメチルセルロース、カルボキシエチルセルロース、ヒドロキシエチルセルロース、それらのリチウム塩、ナトリウム塩、カリウム塩などのアルカリ金属塩、アンモニウム塩等が挙げられる。ゴム系バインダーの具体例としては、例えば、スチレン・ブタジエン共重合体ゴム(SBR)などのスチレン・共役ジエン共重合体、ニトリル・ブタジエン共重合体ゴム(NBR)などのニトリル・共役ジエン共重合体ゴム、ポリオルガノシロキサンなどのシリコーンゴム、アクリル酸アルキルエステルの重合体、アクリル酸アルキルエステルとエチレン性不飽和カルボン酸および/またはその他のエチレン性不飽和単量体との共重合により得られるアクリルゴム、ビニリデンフルオライド共重合体ゴムなどのフッ素ゴム等が挙げられる。   Examples of the binder include, but are not limited to, cellulose ether compounds and rubber binders. Specific examples of the cellulose ether compound include carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl cellulose, alkali metal salts such as lithium salts, sodium salts, and potassium salts, ammonium salts, and the like. Specific examples of rubber binders include, for example, styrene / conjugated diene copolymers such as styrene / butadiene copolymer rubber (SBR), and nitrile / conjugated diene copolymers such as nitrile / butadiene copolymer rubber (NBR). Rubber, silicone rubber such as polyorganosiloxane, polymer of alkyl acrylate, acrylic rubber obtained by copolymerization of alkyl acrylate and ethylenically unsaturated carboxylic acid and / or other ethylenically unsaturated monomers And fluororubber such as vinylidene fluoride copolymer rubber.

正極は、アルミ箔などの集電体上に、正極活物質、導電助剤となる導電性粉末およびバインダーを含有する塗料を塗布し、乾燥させることにより正極合剤層を形成し、加圧成形することにより得られる。   The positive electrode is formed by applying a positive electrode active material, a conductive powder serving as a conductive additive and a binder containing a binder on a current collector such as an aluminum foil, and then drying to form a positive electrode mixture layer, followed by pressure molding Can be obtained.

正極活物質は、特に限定されるものではないが、スピネル構造のリチウム含有複合酸化物、層状構造のリチウム含有複合酸化物、オリビン構造のリチウム複合化合物などを好ましく用いることができる。   The positive electrode active material is not particularly limited, and a lithium-containing composite oxide having a spinel structure, a lithium-containing composite oxide having a layered structure, a lithium composite compound having an olivine structure, or the like can be preferably used.

前記スピネル構造のリチウム含有複合酸化物としては、一般式LiMnに代表されるリチウムマンガン酸化物(構成元素の一部が、Co、Ni、Al、Mg、Zr、Tiなどの元素で置換された複合酸化物も含む)、一般式LiTi12に代表されるリチウムチタン酸化物(構成元素の一部が、Co、Ni、Al、Mg、Zr、Tiなどの元素で置換された複合酸化物も含む)などが例示される。 As the lithium-containing composite oxide having the spinel structure, a lithium manganese oxide represented by the general formula LiMn 2 O 4 (a part of the constituent elements is substituted with an element such as Co, Ni, Al, Mg, Zr, Ti, etc.) And a lithium titanium oxide represented by the general formula Li 4 Ti 5 O 12 (a part of the constituent elements is substituted with an element such as Co, Ni, Al, Mg, Zr, Ti). (Including complex oxides).

また、前記層状構造のリチウム含有複合酸化物としては、一般式LiCoOに代表されるリチウムコバルト酸化物(構成元素の一部が、Ni、Mn、Al、Mg、Zr、Tiなどの元素で置換された複合酸化物も含む)、一般式LiNiOに代表されるリチウムニッケル酸化物(構成元素の一部が、Co、Mn、Al、Mg、ZrおよびTiより選択される少なくとも1種の元素を含む置換元素で置換された複合酸化物も含む)などが例示される。 In addition, as the lithium-containing composite oxide having a layered structure, a lithium cobalt oxide represented by a general formula LiCoO 2 (a part of the constituent elements is replaced with an element such as Ni, Mn, Al, Mg, Zr, Ti, etc.) Composite nickel oxide), lithium nickel oxide represented by the general formula LiNiO 2 (a part of the constituent elements is at least one element selected from Co, Mn, Al, Mg, Zr and Ti) And a complex oxide substituted with a substituted element).

さらに、前記オリビン構造のリチウム複合化合物としては、一般式LiMPO(ただし、MはNi、Co、FeおよびMnより選ばれる少なくとも1種)で表される化合物が例示される。 Further, examples of the olivine-structure lithium composite compound include compounds represented by the general formula LiM 1 PO 4 (wherein M 1 is at least one selected from Ni, Co, Fe and Mn).

特に、スピネル構造のリチウムマンガン酸化物、層状構造のリチウムニッケルコバルト複合酸化物、およびオリビン構造のリチウム複合化合物が、高温での安定性が高いことからより好ましく用いられ、本発明のリチウムイオン二次電池では、正極活物質として、スピネル構造のリチウムマンガン酸化物、層状構造のリチウムニッケルコバルト複合酸化物、およびオリビン構造のリチウム複合化合物より選択される少なくとも1種の化合物を含むように正極が構成される。   In particular, the spinel structure lithium manganese oxide, the layered structure lithium nickel cobalt composite oxide, and the olivine structure lithium composite compound are more preferably used because of their high stability at high temperatures, and the lithium ion secondary of the present invention. In the battery, the positive electrode is configured to include at least one compound selected from a spinel structure lithium manganese oxide, a layered structure lithium nickel cobalt composite oxide, and an olivine structure lithium composite compound as a positive electrode active material. The

前記スピネル構造のリチウムマンガン酸化物としては、Li1+xMn2−x−y3y(ただし、Mは、Co、Ni、Al、Mg、ZrおよびTiより選択される少なくとも1種の元素を含む置換元素であり、−0.05≦x≦0.1、0≦y≦0.3)、Li1+xMn1.5Ni0.5(−0.05≦x≦0.1)などの組成が具体的に例示される。 As the lithium manganese oxide having the spinel structure, Li 1 + x Mn 2-xy M 3y O 4 (where M 3 is at least one element selected from Co, Ni, Al, Mg, Zr and Ti). -0.05 ≦ x ≦ 0.1, 0 ≦ y ≦ 0.3), Li 1 + x Mn 1.5 Ni 0.5 O 4 (−0.05 ≦ x ≦ 0.1) ) And the like are specifically exemplified.

また、前記層状構造のリチウムニッケルコバルト酸化物としては、リチウムニッケル酸化物のNiの一部をCoおよび元素Mで置換した一般式LiNi1−x−yCo2yで表される複合酸化物(ただし、Mは、Mn、Al、Mg、ZrおよびTiより選択される少なくとも1種の元素を含む置換元素であり、0.05≦x≦0.4、0≦y≦0.5、より好ましくは、0.1≦x≦0.4、0.02≦y≦0.5)が具体的に例示され、より具体的には、Li1+xNi1/3Co1/3Mn1/3(−0.05≦x≦0.1)、Li1+xNi0.7Co0.25Al0.05(−0.05≦x≦0.1)などの組成が例示される。 The lithium nickel cobalt oxide having a layered structure is represented by the general formula LiNi 1-xy Co x M 2y O 2 in which a part of Ni in the lithium nickel oxide is substituted with Co and the element M 2. Complex oxide (wherein M 2 is a substitution element containing at least one element selected from Mn, Al, Mg, Zr and Ti, and 0.05 ≦ x ≦ 0.4, 0 ≦ y ≦ 0 .5, more preferably 0.1 ≦ x ≦ 0.4, 0.02 ≦ y ≦ 0.5), and more specifically, Li 1 + x Ni 1/3 Co 1/3 Compositions such as Mn 1/3 O 2 (−0.05 ≦ x ≦ 0.1), Li 1 + x Ni 0.7 Co 0.25 Al 0.05 O 2 (−0.05 ≦ x ≦ 0.1) Is exemplified.

また、大電流での充放電に対応させるためには、正極活物質として、層状構造のリチウムコバルト酸化物(より好ましくは、構成元素の一部が、Ni、Mn、Al、Mg、Zr、Tiなどの元素で置換された複合酸化物)またはリチウムニッケル酸化物(より好ましくは、リチウムニッケルコバルト複合酸化物)を含み、その割合が正極活物質全体の50〜80質量%であることが望ましい。それ以外の活物質としては、スピネル構造のリチウムマンガン酸化物を含有することが望ましい。   In order to cope with charge / discharge with a large current, a lithium cobalt oxide having a layered structure (more preferably, some of the constituent elements are Ni, Mn, Al, Mg, Zr, Ti) as a positive electrode active material. Composite oxide substituted with an element such as) or lithium nickel oxide (more preferably, lithium nickel cobalt composite oxide), and the ratio is desirably 50 to 80% by mass of the whole positive electrode active material. As other active materials, it is desirable to contain a spinel-structure lithium manganese oxide.

導電助剤は、正極合剤層の導電性向上などの目的で必要に応じて添加すればよく、導電助剤となる導電性粉末として、カーボンブラック、ケッチェンブラック、アセチレンブラック、繊維状炭素、黒鉛などの炭素粉末やニッケル粉末などの金属粉末を利用することができる。   The conductive auxiliary agent may be added as necessary for the purpose of improving the conductivity of the positive electrode mixture layer, and as a conductive powder to be a conductive auxiliary agent, carbon black, ketjen black, acetylene black, fibrous carbon, Carbon powder such as graphite and metal powder such as nickel powder can be used.

バインダーには、ポリフッ化ビニリデン、ポリテトラフルオロエチレン等が挙げられるが、これらに限定されるものではない。   Examples of the binder include, but are not limited to, polyvinylidene fluoride and polytetrafluoroethylene.

正極活物質の質量Pと負極活物質の質量Nとの比:P/Nの好適な範囲は、正極活物質の種類によっても変化するが、層状構造のリチウム含有複合酸化物を主体とする場合は、正極合剤層と負極合剤層とが対向する面において2.05〜2.30とするのが望ましい。P/Nの比をこの範囲とすることにより、正極と負極の容量の比を最適化することができ、優れたサイクル特性を得ることができる。   Ratio of the positive electrode active material mass P to the negative electrode active material mass N: The preferred range of P / N varies depending on the type of the positive electrode active material, but is mainly composed of a lithium-containing composite oxide having a layered structure. Is preferably 2.05 to 2.30 on the surface where the positive electrode mixture layer and the negative electrode mixture layer face each other. By setting the P / N ratio within this range, the capacity ratio between the positive electrode and the negative electrode can be optimized, and excellent cycle characteristics can be obtained.

前記負極および正極の間には、融点の異なる複数の熱可塑性樹脂膜が積層されて構成された多孔質フィルムがセパレータとして用いられる。一般に、リチウムイオン二次電池に使用されているポリオレフィンの単一の多孔質フィルムは、ある程度の耐熱性を持たせながら、135℃付近でシャットダウンを生じるよう、シャットダウン温度付近に融点を持つ樹脂が用いられている。しかし、フィルムの持つ大きなひずみのため、電動工具などに用いられる場合は、シャットダウンにまで至らないものの、電池の発熱によりフィルムの収縮や目詰まりを生じやすくなり、短絡や特性低下を招く場合がある。また、耐熱性を考慮して樹脂の融点を高くすると、シャットダウンを生じにくくなり、安全性の点で問題を生じる。   A porous film constituted by laminating a plurality of thermoplastic resin films having different melting points is used as a separator between the negative electrode and the positive electrode. In general, a single porous film of polyolefin used in lithium ion secondary batteries is made of a resin having a melting point near the shutdown temperature so as to cause shutdown at around 135 ° C while maintaining a certain degree of heat resistance. It has been. However, due to the large distortion of the film, when it is used for power tools, etc., it does not lead to shutdown, but the film heat generation tends to cause shrinkage or clogging of the film, which may cause short circuit or deterioration of characteristics. . Further, if the melting point of the resin is increased in consideration of heat resistance, it is difficult to cause a shutdown, which causes a problem in terms of safety.

一方、本発明でセパレータとなる積層体では、シャットダウンを生じる融点が120〜140℃の多孔質樹脂層(低融点樹脂層)のほかに、融点が150℃以上の多孔質樹脂層(高融点樹脂層)を含むので、電動工具など電池内部温度が上昇しやすい用途に用いられる場合であっても、セパレータの熱収縮が抑制され、目詰まりを生じにくく、セパレータの特性が安定して維持される。このため、前述した負極活物質や正極活物質の持つ特徴を効果的に発揮させることができ、大電流での充放電による特性劣化が少ない電池とすることができる。前記セパレータは、高融点樹脂層と低融点樹脂層の二層でも良いが、特に、両表面を高融点樹脂層、内部に低融点樹脂層を配置した三層以上の積層体、などが上記目的に適しており、より好適に用いられる。   On the other hand, in the laminate as a separator in the present invention, a porous resin layer (high melting point resin) having a melting point of 150 ° C. or higher, in addition to a porous resin layer (low melting point resin layer) having a melting point of 120 to 140 ° C. Layer), even when used in applications where the battery internal temperature tends to rise, such as electric tools, the thermal contraction of the separator is suppressed, clogging is less likely to occur, and the characteristics of the separator are stably maintained. . For this reason, the characteristic which the negative electrode active material mentioned above and a positive electrode active material have can be exhibited effectively, and it can be set as a battery with few characteristic deterioration by charging / discharging by a large current. The separator may be two layers of a high melting point resin layer and a low melting point resin layer, and in particular, a laminate of three or more layers in which both surfaces are a high melting point resin layer and a low melting point resin layer is disposed inside, etc. It is more suitable for use.

低融点樹脂層には、ポリエチレン、ポリブテン、エチレンプロピレン共重合体などの多孔質フィルムが用いられ、特に高密度ポリエチレンが好ましく用いられる。また、高融点樹脂層には、ポリプロピレン、ポリ4−メチルペンテン−1、ポリ3−メチルブテン−1などの多孔質フィルムが用いられ、特にポリプロピレンが好ましく用いられる。   For the low melting point resin layer, a porous film such as polyethylene, polybutene, ethylene propylene copolymer or the like is used, and high density polyethylene is particularly preferably used. For the high melting point resin layer, a porous film such as polypropylene, poly-4-methylpentene-1, poly-3-methylbutene-1 is used, and polypropylene is particularly preferably used.

前記融点の異なる複数の熱可塑性樹脂膜が積層されて構成された多孔質フィルムとしては、延伸法や抽出法などにより形成された融点が120〜140℃の多孔質樹脂層と、同じく延伸法や抽出法などにより形成された融点が150℃以上の多孔質樹脂層とを重ね合わせ、延伸、圧着、接着剤などにより貼り合わせて形成する方法、あるいは、融点が120〜140℃の樹脂層と融点が150℃以上の樹脂層とを熱圧着し、延伸法などにより多孔化する方法などにより製造された市販の積層フィルムを用いることができる。   As a porous film constituted by laminating a plurality of thermoplastic resin films having different melting points, a porous resin layer having a melting point of 120 to 140 ° C. formed by a stretching method or an extraction method, A method in which a porous resin layer having a melting point of 150 ° C. or higher formed by an extraction method or the like is overlapped and bonded by stretching, pressure bonding, adhesive, or the like, or a resin layer having a melting point of 120 to 140 ° C. and a melting point However, a commercially available laminated film manufactured by a method of thermocompression bonding with a resin layer having a temperature of 150 ° C. or higher and making it porous by a stretching method or the like can be used.

高融点樹脂層の厚みは、セパレータの熱収縮抑制のために、1μm以上であることが好ましく、より好ましくは3μm以上であって、一方、セパレータ全体の厚みを薄くするために、15μm以下であることが好ましく、より好ましくは10μm以下である。また、低融点樹脂層の厚みは、シャットダウンを確実にするために、3μm以上であることが好ましく、より好ましくは5μm以上であって、一方、セパレータ全体の厚みを薄くするために、20μm以下であることが好ましく、より好ましくは15μm以下である。   The thickness of the high melting point resin layer is preferably 1 μm or more, more preferably 3 μm or more in order to suppress thermal shrinkage of the separator, and on the other hand, 15 μm or less in order to reduce the thickness of the entire separator. Preferably, it is 10 μm or less. In addition, the thickness of the low melting point resin layer is preferably 3 μm or more in order to ensure shutdown, more preferably 5 μm or more. On the other hand, in order to reduce the thickness of the entire separator, the thickness is 20 μm or less. It is preferable that the thickness is 15 μm or less.

また、本発明における非水電解液は、特に限定されるものではなく、有機溶媒などの非水溶媒にリチウム塩などの電解質塩を溶解させた汎用の非水電解液が一般に用いられる。   The non-aqueous electrolyte in the present invention is not particularly limited, and a general-purpose non-aqueous electrolyte obtained by dissolving an electrolyte salt such as a lithium salt in a non-aqueous solvent such as an organic solvent is generally used.

非水溶媒としては、例えば、ジメチルカーボネート、ジエチルカーボネート、メチルエチルカーボネート、プロピオン酸メチル、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ガンマーブチロラクトン、エチレングリコールサルファイト、1,2−ジメトキシエタン、1,3−ジオキソラン、テトラヒドロフラン、2−メチル−テトラヒドロフラン、ジエチルエーテル等の溶媒を単独あるいは数種類混合した混合溶媒を用いることができる。   Examples of the non-aqueous solvent include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propionate, ethylene carbonate, propylene carbonate, butylene carbonate, gamma-butyrolactone, ethylene glycol sulfite, 1,2-dimethoxyethane, 1,3- Solvents such as dioxolane, tetrahydrofuran, 2-methyl-tetrahydrofuran, diethyl ether and the like can be used singly or as a mixed solvent in which several kinds are mixed.

電解質塩としては、例えば、LiClO、LiPF、LiBF、LiAsF、LiSbF、LiCFSO、LiCFCO、Li(SO、LiN(CFSO、LiC(CFSO、LiC2n+1SO(n≧2)、LiN(RfOSO〔ここでRfはフルオロアルキル基〕等が挙げられる。電解液中の電解質塩の濃度としては、0.3〜1.7mol/l、特に0.5〜1.5mol/lが好ましい。 As the electrolyte salt, for example, LiClO 4, LiPF 6, LiBF 4, LiAsF 6, LiSbF 6, LiCF 3 SO 3, LiCF 3 CO 2, Li 2 C 2 F 4 (SO 3) 2, LiN (CF 3 SO 2 ) 2 , LiC (CF 3 SO 2 ) 3 , LiC n F 2n + 1 SO 3 (n ≧ 2), LiN (RfOSO 2 ) 2 [where Rf is a fluoroalkyl group] and the like. The concentration of the electrolyte salt in the electrolytic solution is preferably 0.3 to 1.7 mol / l, particularly 0.5 to 1.5 mol / l.

上記電解液に、充放電サイクル特性や貯蔵特性の向上のため、ビニレンカーボネートまたはその誘導体、シクロヘキシルベンゼンやターシャリーブチルベンゼンなどのアルキルベンゼン類、ビフェニル、プロパンスルトンなどの環状スルトン、ジフェニルジスルフィドなどのスルフィド類などの添加剤を含有させてもよい。添加量は、電解液中で0.1〜10質量%とすればよく、0.5質量%以上がより好ましく、5質量%以下がより好ましい。   In order to improve the charge / discharge cycle characteristics and storage characteristics of the above electrolyte, vinylene carbonate or its derivatives, alkylbenzenes such as cyclohexylbenzene and tertiary butylbenzene, cyclic sultones such as biphenyl and propane sultone, and sulfides such as diphenyl disulfide Additives such as may be included. The addition amount may be 0.1 to 10% by mass in the electrolytic solution, more preferably 0.5% by mass or more, and more preferably 5% by mass or less.

実施例1
負極活物質として、波長514.5nmのアルゴンレーザーで励起させた時のラマンスペクトルのR値が0.65で、002面の面間隔d002が0.335nm、BET比表面積が2.2m/gの黒鉛粉末80%と、R値が0.15の黒鉛粉末20%を混合したものを用い、バインダーとしてカルボキシメチルセルロースとスチレン・ブタジエン共重合体ゴムを用い、溶媒としての水と共に質量比98:1:1の割合で混合し、スラリー状の負極合剤含有ペーストを調製した。得られた負極合剤含有ペーストを厚さ10μmの銅箔からなる負極集電体の両面に塗布し、乾燥して負極合剤層を形成し、ローラーで負極合剤層の密度が1.5g/cmになるまで加圧成形した後、所定の幅および長さになるようにして切断して負極を作製した。
Example 1
As the negative electrode active material, the R value of the Raman spectrum when excited with an argon laser having a wavelength of 514.5 nm is 0.65, the interplanar spacing d 002 of the 002 plane is 0.335 nm, and the BET specific surface area is 2.2 m 2 / a mixture of 80% of graphite powder of 20 g and 20% of graphite powder having an R value of 0.15, carboxymethyl cellulose and styrene-butadiene copolymer rubber as a binder, and a mass ratio of 98 with water as a solvent: The mixture was mixed at a ratio of 1: 1 to prepare a slurry-like negative electrode mixture-containing paste. The obtained negative electrode mixture-containing paste was applied to both sides of a negative electrode current collector made of a copper foil having a thickness of 10 μm, dried to form a negative electrode mixture layer, and the density of the negative electrode mixture layer was 1.5 g with a roller. After being pressure-molded to reach / cm 3 , it was cut so as to have a predetermined width and length to produce a negative electrode.

正極活物質としてLiCoOを66.5質量部とLiMnを28.5質量部、導電助剤としてケッチェンブラック2.5質量部、バインダーとしてポリフッ化ビニリデン2.5質量部を、N−メチル−2−ピロリドンを溶剤として均一になるように混合し、正極合剤含有ペーストを調製した。そのペーストを厚さ15μmのアルミニウム箔からなる正極集電体の両面に塗布し、乾燥して正極合剤層を形成し、ローラーで正極合剤層を所定の厚みになるまで加圧成形した後、所定の幅および長さになるように切断して正極を作製した。 66.5 parts by mass of LiCoO 2 as a positive electrode active material, 28.5 parts by mass of LiMn 2 O 4 , 2.5 parts by mass of Ketjen black as a conductive additive, 2.5 parts by mass of polyvinylidene fluoride as a binder, -Methyl-2-pyrrolidone was mixed uniformly as a solvent to prepare a positive electrode mixture-containing paste. After applying the paste on both sides of a positive electrode current collector made of an aluminum foil having a thickness of 15 μm, drying to form a positive electrode mixture layer, and pressing the positive electrode mixture layer to a predetermined thickness with a roller. Then, a positive electrode was produced by cutting to a predetermined width and length.

上記負極および正極の間に、厚み約7μmのポリプロピレンフィルム(融点:165℃)/厚み約7μmのポリエチレンフィルム(融点:125℃)/厚み約7μmのポリプロピレンフィルム(融点:165℃)からなる総厚み約20μm、開口率46%の多孔性積層フィルムをセパレータとして配置して渦巻状に捲回し、円筒型の外装缶内に挿入した。正極合剤層と負極合剤層とが対向する面において、正極活物質の質量Pと前記負極活物質の質量Nとの比P/Nは2.17であった。   Total thickness of polypropylene film (melting point: 165 ° C.) with a thickness of about 7 μm / polyethylene film (melting point: 125 ° C.) with a thickness of about 7 μm / polypropylene film (melting point: 165 ° C.) with a thickness of about 7 μm between the negative electrode and the positive electrode. A porous laminated film having a diameter of about 20 μm and an opening ratio of 46% was placed as a separator, wound in a spiral shape, and inserted into a cylindrical outer can. On the surface where the positive electrode mixture layer and the negative electrode mixture layer face each other, the ratio P / N between the mass P of the positive electrode active material and the mass N of the negative electrode active material was 2.17.

非水電解液は、エチレンカーボネートとメチルエチルカーボネートとを体積比で1:2で混合した溶媒中に、LiPFを1.2モル/リットルの割合で溶解し、さらに、ビニレンカーボネートを2質量%添加した溶液を用い、直径18mm、高さ65mmの円筒型のリチウムイオン二次電池とした。 The nonaqueous electrolytic solution was prepared by dissolving LiPF 6 at a ratio of 1.2 mol / liter in a solvent in which ethylene carbonate and methyl ethyl carbonate were mixed at a volume ratio of 1: 2, and further 2% by mass of vinylene carbonate. Using the added solution, a cylindrical lithium ion secondary battery having a diameter of 18 mm and a height of 65 mm was obtained.

実施例2
負極合剤層の密度を1.58g/cmとし、PN比を2.22とした以外は実施例1と同様にしてリチウムイオン二次電池を作製した。
Example 2
A lithium ion secondary battery was produced in the same manner as in Example 1 except that the density of the negative electrode mixture layer was 1.58 g / cm 3 and the PN ratio was 2.22.

実施例3
負極活物質として、波長514.5nmのアルゴンレーザーで励起させた時のラマンスペクトルのR値が0.65で、002面の面間隔d002が0.335nm、BET比表面積が2.2m/gの黒鉛粉末の割合を100%とし、正極の導電助剤として、ケッチェンブラックに代えてアセチレンブラックを用いた以外は、実施例1と同様にしてリチウムイオン二次電池を作製した。
Example 3
As the negative electrode active material, the R value of the Raman spectrum when excited with an argon laser having a wavelength of 514.5 nm is 0.65, the interplanar spacing d 002 of the 002 plane is 0.335 nm, and the BET specific surface area is 2.2 m 2 / A lithium ion secondary battery was fabricated in the same manner as in Example 1, except that the ratio of g graphite powder was 100%, and acetylene black was used instead of ketjen black as the positive electrode conductive assistant.

実施例4
正極活物質のLiCoOに代えて、LiNi0.82Co0.10Al0.03を用い、正極の導電助剤として、ケッチェンブラックに代えてアセチレンブラックを用いた以外は、実施例1と同様にしてリチウムイオン二次電池を作製した。
Example 4
Example except that LiNi 0.82 Co 0.10 Al 0.03 O 2 was used instead of LiCoO 2 of the positive electrode active material, and acetylene black was used instead of ketjen black as the conductive assistant for the positive electrode. In the same manner as in Example 1, a lithium ion secondary battery was produced.

比較例1
負極活物質として、R値が0.25の黒鉛粉末のみを用いたこと以外は実施例1と同様にしてリチウムイオン二次電池を作製した。
Comparative Example 1
A lithium ion secondary battery was produced in the same manner as in Example 1 except that only graphite powder having an R value of 0.25 was used as the negative electrode active material.

比較例2
厚み25μm、開口率42%のポリエチレンからなる単一層の多孔性フィルムをセパレータとして用いた以外は実施例1と同様にしてリチウムイオン二次電池を作製した。
Comparative Example 2
A lithium ion secondary battery was produced in the same manner as in Example 1 except that a single-layer porous film made of polyethylene having a thickness of 25 μm and an aperture ratio of 42% was used as a separator.

比較例3
負極合剤層の密度を1.67g/cmとした以外は実施例1と同様にしてリチウムイオン二次電池を作製した。
Comparative Example 3
A lithium ion secondary battery was produced in the same manner as in Example 1 except that the density of the negative electrode mixture layer was 1.67 g / cm 3 .

比較例4
負極合剤層の密度を1.35g/cmとした以外は実施例1と同様にしてリチウムイオン二次電池を作製した。
Comparative Example 4
A lithium ion secondary battery was produced in the same manner as in Example 1, except that the density of the negative electrode mixture layer was 1.35 g / cm 3 .

比較例5
セパレータとして、ポリプロピレンフィルム/ポリエチレンフィルム(融点:105℃)/ポリプロピレンフィルムからなる多孔性積層フィルムを用いた以外は、実施例1と同様にしてリチウムイオン二次電池を作製した。
Comparative Example 5
A lithium ion secondary battery was produced in the same manner as in Example 1 except that a porous laminated film composed of polypropylene film / polyethylene film (melting point: 105 ° C.) / Polypropylene film was used as the separator.

作製した電池に対し、0.75Aの定電流および電圧4.2Vの定電圧による定電流−定電圧充電(総充電時間:2.5時間)を行った後、1.5Aで定電流放電(放電終止電圧:2.5V)を行い、初期放電容量を測定した。次に、前記定電流−定電圧充電の後、25A(放電レートは約16C)で定電流放電(放電終止電圧:2.0V)を行って大電流放電での容量を測定し、前記初期放電容量に対する割合を大電流特性として評価した。さらに、前記初期放電容量の測定と同じ条件で充放電を行い、このときの容量の初期放電容量に対する割合を、容量回復率として評価した。結果を表1に示す。   The prepared battery was subjected to constant current-constant voltage charging (total charging time: 2.5 hours) with a constant current of 0.75 A and a constant voltage of 4.2 V, and then a constant current discharge at 1.5 A ( Discharge final voltage: 2.5V), and the initial discharge capacity was measured. Next, after the constant current-constant voltage charge, a constant current discharge (discharge end voltage: 2.0 V) is performed at 25 A (discharge rate is about 16 C) to measure a capacity in a large current discharge, and the initial discharge The ratio to the capacity was evaluated as a large current characteristic. Furthermore, charging / discharging was performed under the same conditions as the measurement of the initial discharge capacity, and the ratio of the capacity at this time to the initial discharge capacity was evaluated as a capacity recovery rate. The results are shown in Table 1.

Figure 2009123715
Figure 2009123715

また、大電流で充放電サイクルを繰り返し、1サイクル目の容量に対する100サイクル、200サイクルおよび500サイクル経過時の容量の割合を測定し、サイクル特性を評価した。結果を表2に示す。充電は、4Aの定電流および電圧4.2Vの定電圧による定電流−定電圧充電とし、放電は、3Aの定電流放電(放電終止電圧:2.0V)とした。   In addition, the charge / discharge cycle was repeated with a large current, and the ratio of the capacity at the elapse of 100 cycles, 200 cycles and 500 cycles with respect to the capacity of the first cycle was measured to evaluate the cycle characteristics. The results are shown in Table 2. Charging was constant current-constant voltage charging with a constant current of 4 A and a constant voltage of 4.2 V, and discharging was a constant current discharge of 3 A (discharge end voltage: 2.0 V).

Figure 2009123715
Figure 2009123715

さらに、実施例1、比較例2および比較例5で用いたのと同じセパレータを所定サイズに切断し、両側からガラス板に挟み、130℃の恒温槽内で1時間放置した後取り出し、幅方向の長さの変化、およびガーレー値の変化の測定を行った。試験前の長さに対する変化量の割合を収縮率とし、試験前のガーレー値を100としてガーレー値の相対値を求めた結果を表3に示す。   Further, the same separator as used in Example 1, Comparative Example 2 and Comparative Example 5 was cut into a predetermined size, sandwiched between glass plates from both sides, left in a thermostatic bath at 130 ° C. for 1 hour, and then taken out. The change in length and the change in Gurley value were measured. Table 3 shows the result of calculating the relative value of the Gurley value with the ratio of the change amount with respect to the length before the test as the shrinkage and the Gurley value before the test as 100.

Figure 2009123715
Figure 2009123715

実施例1〜4のリチウムイオン二次電池は、電極での反応が均一化され、充放電による電池内部の温度上昇にも対応できる電池構成であるため、大電流特性に優れ、10Cを超える放電であっても、容量後の特性劣化が少なく、サイクル特性の良好な電池となっていた。一方、比較例1では、負極活物質のR値が小さいため、粒子表面でのリチウムイオンの挿入・脱離が困難になり大電流での充放電に対応できなくなって容量が低下した。また、単一層の多孔性フィルムを用いた比較例2では、高温でのガーレー値の上昇に示されるように、セパレータの目詰まりが徐々に進行してサイクル特性が低下し、セパレータの熱収縮による短絡の危険も生じた。比較例3および4では、負極合剤層の密度が適切ではないため、充放電における合剤層内部の反応が不均一になってサイクル特性が低下した。さらに、比較例5では、セパレータの収縮はないものの、低融点樹脂層の融点が低すぎるため、10Cを超える放電を行った場合にセパレータの特性が変化して、容量劣化を生じた。   Since the lithium ion secondary batteries of Examples 1 to 4 have a battery configuration in which the reaction at the electrodes is made uniform and the temperature inside the battery due to charging and discharging can be dealt with, it is excellent in large current characteristics and discharge exceeding 10 C. Even so, the battery has good cycle characteristics with little deterioration in characteristics after capacity. On the other hand, in Comparative Example 1, since the R value of the negative electrode active material was small, it was difficult to insert and desorb lithium ions on the particle surface, and it was impossible to handle charge / discharge with a large current, resulting in a decrease in capacity. In Comparative Example 2 using a single-layer porous film, as shown by the increase in the Gurley value at high temperature, the clogging of the separator gradually proceeds and the cycle characteristics deteriorate, and the heat shrinkage of the separator There was also the danger of a short circuit. In Comparative Examples 3 and 4, since the density of the negative electrode mixture layer was not appropriate, the reaction inside the mixture layer during charge and discharge became non-uniform and the cycle characteristics deteriorated. Further, in Comparative Example 5, although the separator was not contracted, the melting point of the low melting point resin layer was too low, so that when the discharge exceeding 10 C was performed, the characteristics of the separator changed and capacity was deteriorated.

Claims (4)

負極活物質を含有する負極合剤層を有する負極、正極活物質を含有する正極合剤層を有する正極、セパレータおよび非水電解液を有するリチウムイオン二次電池であって、
前記負極活物質として、波長514.5nmのアルゴンレーザーで励起させた時のラマンスペクトルのR値が0.3以上0.8以下であり、002面の面間隔d002が0.34nm以下である炭素材料を含有し、
負極活物質における前記炭素材料の割合が60質量%以上であり、
前記負極合剤層の密度が1.4〜1.6g/cmであり、
前記正極活物質として、スピネル構造のリチウムマンガン酸化物、層状構造のリチウムニッケルコバルト複合酸化物およびオリビン構造のリチウム複合化合物より選択される少なくとも1種の化合物を含み、
前記セパレータが、融点が120〜140℃の多孔質樹脂層と、融点が150℃以上の多孔質樹脂層との積層体であることを特徴とするリチウムイオン二次電池。
A negative electrode having a negative electrode mixture layer containing a negative electrode active material, a positive electrode having a positive electrode mixture layer containing a positive electrode active material, a separator, and a lithium ion secondary battery having a non-aqueous electrolyte,
When the negative electrode active material is excited with an argon laser having a wavelength of 514.5 nm, the R value of the Raman spectrum is 0.3 or more and 0.8 or less, and the surface spacing d 002 of the 002 plane is 0.34 nm or less. Containing carbon materials,
The ratio of the carbon material in the negative electrode active material is 60% by mass or more,
The density of the negative electrode mixture layer is 1.4 to 1.6 g / cm 3 ,
As the positive electrode active material, comprising at least one compound selected from spinel structure lithium manganese oxide, layered structure lithium nickel cobalt composite oxide and olivine structure lithium composite compound,
The lithium ion secondary battery, wherein the separator is a laminate of a porous resin layer having a melting point of 120 to 140 ° C and a porous resin layer having a melting point of 150 ° C or higher.
前記負極活物質のBET比表面積が、1.5〜3.6m/gである請求項1に記載のリチウムイオン二次電池。 The lithium ion secondary battery according to claim 1, wherein the negative electrode active material has a BET specific surface area of 1.5 to 3.6 m 2 / g. 正極活物質として、スピネル構造のリチウムマンガン酸化物と、層状構造のリチウムコバルト複合酸化物とを含み、前記リチウムコバルト複合酸化物の割合が、正極活物質全体の50〜80質量%である請求項1または2に記載のリチウムイオン二次電池。   The positive electrode active material includes a spinel structure lithium manganese oxide and a layered structure lithium cobalt composite oxide, and the proportion of the lithium cobalt composite oxide is 50 to 80% by mass of the whole positive electrode active material. The lithium ion secondary battery according to 1 or 2. 前記正極活物質の質量Pと前記負極活物質の質量Nとの比P/Nを、前記正極合剤層と前記負極合剤層とが対向する面において2.05〜2.30とした請求項1〜3のいずれかに記載のリチウムイオン二次電池。

The ratio P / N between the mass P of the positive electrode active material and the mass N of the negative electrode active material is set to 2.05 to 2.30 on the surface where the positive electrode mixture layer and the negative electrode mixture layer face each other. Item 4. The lithium ion secondary battery according to any one of Items 1 to 3.

JP2009056404A 2007-06-28 2009-03-10 Lithium ion secondary battery Pending JP2009123715A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009056404A JP2009123715A (en) 2007-06-28 2009-03-10 Lithium ion secondary battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2007170849 2007-06-28
JP2009056404A JP2009123715A (en) 2007-06-28 2009-03-10 Lithium ion secondary battery

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP2008165378A Division JP2009032682A (en) 2007-06-28 2008-06-25 Lithium-ion secondary battery

Publications (1)

Publication Number Publication Date
JP2009123715A true JP2009123715A (en) 2009-06-04

Family

ID=40402950

Family Applications (2)

Application Number Title Priority Date Filing Date
JP2008165378A Pending JP2009032682A (en) 2007-06-28 2008-06-25 Lithium-ion secondary battery
JP2009056404A Pending JP2009123715A (en) 2007-06-28 2009-03-10 Lithium ion secondary battery

Family Applications Before (1)

Application Number Title Priority Date Filing Date
JP2008165378A Pending JP2009032682A (en) 2007-06-28 2008-06-25 Lithium-ion secondary battery

Country Status (1)

Country Link
JP (2) JP2009032682A (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102218871A (en) * 2011-04-14 2011-10-19 万向电动汽车有限公司 Preparation method of modified diaphragm for lithium-ion secondary battery as well as product and preparation device thereof
JP2012181976A (en) * 2011-03-01 2012-09-20 Hitachi Ltd Lithium secondary battery abnormally charged state detection device and inspection method
JP2012227154A (en) * 2010-09-14 2012-11-15 Hitachi Maxell Energy Ltd Nonaqueous secondary battery
JP2014517459A (en) * 2011-05-23 2014-07-17 エルジー ケム. エルティーディ. High energy density lithium secondary battery with improved energy density characteristics
KR20140119184A (en) * 2012-03-07 2014-10-08 닛산 지도우샤 가부시키가이샤 Positive electrode active material, positive electrode for electrical device, and electrical device
KR20150039371A (en) * 2013-10-02 2015-04-10 주식회사 엘지화학 Cathode active material with improved safety and electrochemical device comprising the same
KR20150060027A (en) * 2013-11-25 2015-06-03 주식회사 엘지화학 Cathode Active Material and Lithium Secondary Battery Containing the Same
US9099739B2 (en) 2011-10-20 2015-08-04 Samsung Sdi Co., Ltd. Lithium secondary battery
US10305100B2 (en) 2011-09-16 2019-05-28 Samsung Sdi Co., Ltd. Composite cathode active material, and cathode and lithium battery including the material

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5219621B2 (en) * 2007-08-22 2013-06-26 三洋電機株式会社 Non-aqueous electrolyte battery
JP5487821B2 (en) * 2009-02-27 2014-05-14 住友化学株式会社 Lithium composite metal oxide and positive electrode active material
JP5234662B2 (en) * 2009-09-17 2013-07-10 日立マクセル株式会社 Battery separator and lithium secondary battery
JP5234817B2 (en) * 2009-09-17 2013-07-10 日立マクセル株式会社 Battery separator and lithium secondary battery
JP5576740B2 (en) * 2009-12-14 2014-08-20 日立マクセル株式会社 Electrochemical element
KR101520210B1 (en) * 2011-03-28 2015-05-13 도요타지도샤가부시키가이샤 Lithium ion secondary battery
CN103503204B (en) 2011-05-23 2016-03-09 株式会社Lg化学 The height with the power density properties of enhancing exports lithium secondary battery
JP2014513409A (en) 2011-05-23 2014-05-29 エルジー ケム. エルティーディ. High power lithium secondary battery with improved power density characteristics
WO2012161477A2 (en) 2011-05-23 2012-11-29 주식회사 엘지화학 High output lithium secondary battery having enhanced output density characteristic
JP2014514726A (en) * 2011-05-23 2014-06-19 エルジー ケム. エルティーディ. High energy density lithium secondary battery with improved energy density characteristics
CN103563140B (en) 2011-05-23 2015-11-25 株式会社Lg化学 The height with the power density properties of enhancing exports lithium secondary battery
EP2720302B1 (en) 2011-07-13 2016-04-06 LG Chem, Ltd. High-energy lithium secondary battery having improved energy density characteristics
JP2014179165A (en) * 2013-03-13 2014-09-25 Hitachi Maxell Ltd Separator for electrochemical devices, and electrochemical device
EP2975676B1 (en) * 2013-03-15 2018-10-03 Nissan Motor Co., Ltd Non-aqueous electrolyte secondary battery cathode, and non-aqueous electrolyte secondary battery using same
CN105103344B (en) * 2013-03-15 2018-03-16 日产自动车株式会社 Positive electrode for nonaqueous electrolyte secondary battery and use its rechargeable nonaqueous electrolytic battery
JP7024439B2 (en) * 2017-03-17 2022-02-24 Tdk株式会社 Negative negative for lithium ion secondary battery and lithium ion secondary battery
JPWO2019073595A1 (en) * 2017-10-13 2020-10-22 株式会社エンビジョンAescエナジーデバイス Lithium ion secondary battery

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04171660A (en) * 1990-11-05 1992-06-18 Matsushita Electric Ind Co Ltd Nonaqueous-electrolyte secondary battery
JP2625798B2 (en) * 1987-07-04 1997-07-02 東レ株式会社 Electrolyte separator
JPH1154120A (en) * 1997-07-29 1999-02-26 Japan Storage Battery Co Ltd Lithium ion secondary battery
JP2000012030A (en) * 1998-06-24 2000-01-14 Shin Kobe Electric Mach Co Ltd Nonaqueous electrolyte secondary battery
JP2000090982A (en) * 1998-07-14 2000-03-31 Denso Corp Nonaqueous electrolyte secondary battery
JP2000133236A (en) * 1998-08-20 2000-05-12 Japan Storage Battery Co Ltd Separator for nonaqueous electrolyte secondary battery
JP2002110253A (en) * 2000-09-29 2002-04-12 Sanyo Electric Co Ltd Non-aqueous electrolyte secondary battery
JP2002175807A (en) * 2000-12-08 2002-06-21 Gs-Melcotec Co Ltd Nonaqueous electrolyte secondary battery
JP2002216745A (en) * 2001-01-23 2002-08-02 Sanyo Electric Co Ltd Lithium secondary battery
JP2003331922A (en) * 2002-05-17 2003-11-21 Sony Corp Cell
JP2004273444A (en) * 2003-02-20 2004-09-30 Mitsubishi Chemicals Corp Lithium secondary battery, active substance for negative electrode thereof and negative electrode thereof
JP2004342500A (en) * 2003-05-16 2004-12-02 Matsushita Electric Ind Co Ltd Non-aqueous electrolyte secondary battery and battery charge/discharge system

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2625798B2 (en) * 1987-07-04 1997-07-02 東レ株式会社 Electrolyte separator
JPH04171660A (en) * 1990-11-05 1992-06-18 Matsushita Electric Ind Co Ltd Nonaqueous-electrolyte secondary battery
JPH1154120A (en) * 1997-07-29 1999-02-26 Japan Storage Battery Co Ltd Lithium ion secondary battery
JP2000012030A (en) * 1998-06-24 2000-01-14 Shin Kobe Electric Mach Co Ltd Nonaqueous electrolyte secondary battery
JP2000090982A (en) * 1998-07-14 2000-03-31 Denso Corp Nonaqueous electrolyte secondary battery
JP2000133236A (en) * 1998-08-20 2000-05-12 Japan Storage Battery Co Ltd Separator for nonaqueous electrolyte secondary battery
JP2002110253A (en) * 2000-09-29 2002-04-12 Sanyo Electric Co Ltd Non-aqueous electrolyte secondary battery
JP2002175807A (en) * 2000-12-08 2002-06-21 Gs-Melcotec Co Ltd Nonaqueous electrolyte secondary battery
JP2002216745A (en) * 2001-01-23 2002-08-02 Sanyo Electric Co Ltd Lithium secondary battery
JP2003331922A (en) * 2002-05-17 2003-11-21 Sony Corp Cell
JP2004273444A (en) * 2003-02-20 2004-09-30 Mitsubishi Chemicals Corp Lithium secondary battery, active substance for negative electrode thereof and negative electrode thereof
JP2004342500A (en) * 2003-05-16 2004-12-02 Matsushita Electric Ind Co Ltd Non-aqueous electrolyte secondary battery and battery charge/discharge system

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012227154A (en) * 2010-09-14 2012-11-15 Hitachi Maxell Energy Ltd Nonaqueous secondary battery
JP2012181976A (en) * 2011-03-01 2012-09-20 Hitachi Ltd Lithium secondary battery abnormally charged state detection device and inspection method
CN102218871B (en) * 2011-04-14 2014-08-27 万向电动汽车有限公司 Preparation method of modified diaphragm for lithium-ion secondary battery as well as product and preparation device thereof
CN102218871A (en) * 2011-04-14 2011-10-19 万向电动汽车有限公司 Preparation method of modified diaphragm for lithium-ion secondary battery as well as product and preparation device thereof
JP2014517459A (en) * 2011-05-23 2014-07-17 エルジー ケム. エルティーディ. High energy density lithium secondary battery with improved energy density characteristics
US10305100B2 (en) 2011-09-16 2019-05-28 Samsung Sdi Co., Ltd. Composite cathode active material, and cathode and lithium battery including the material
US9099739B2 (en) 2011-10-20 2015-08-04 Samsung Sdi Co., Ltd. Lithium secondary battery
KR101674278B1 (en) 2012-03-07 2016-11-08 닛산 지도우샤 가부시키가이샤 Positive electrode active material, positive electrode for electrical device, and electrical device
KR20140119184A (en) * 2012-03-07 2014-10-08 닛산 지도우샤 가부시키가이샤 Positive electrode active material, positive electrode for electrical device, and electrical device
KR20150039371A (en) * 2013-10-02 2015-04-10 주식회사 엘지화학 Cathode active material with improved safety and electrochemical device comprising the same
KR101666048B1 (en) * 2013-10-02 2016-10-13 주식회사 엘지화학 Cathode active material with improved safety and electrochemical device comprising the same
KR101616722B1 (en) * 2013-11-25 2016-04-29 주식회사 엘지화학 Cathode Active Material and Lithium Secondary Battery Containing the Same
KR20150060027A (en) * 2013-11-25 2015-06-03 주식회사 엘지화학 Cathode Active Material and Lithium Secondary Battery Containing the Same

Also Published As

Publication number Publication date
JP2009032682A (en) 2009-02-12

Similar Documents

Publication Publication Date Title
JP2009123715A (en) Lithium ion secondary battery
WO2009157507A1 (en) Lithium ion secondary cell
JP6098878B2 (en) Non-aqueous electrolyte secondary battery
JP5621770B2 (en) Non-aqueous electrolyte secondary battery and method for producing non-aqueous electrolyte secondary battery
JP5094084B2 (en) Nonaqueous electrolyte secondary battery
CN106063019B (en) Nonaqueous electrolyte secondary battery
JPWO2011162169A1 (en) Lithium ion secondary battery
JP2008097879A (en) Lithium ion secondary battery
KR101671106B1 (en) Non aqueous electrolyte secondary battery
WO2013038939A1 (en) Lithium secondary-battery pack, electronic device using same, charging system, and charging method
JP2012094459A (en) Lithium ion secondary battery
WO2012161184A1 (en) Electrolyte solution for nonaqueous secondary battery, and secondary battery
JP2009277395A (en) Nonaqueous secondary battery, and nonaqueous secondary battery system
JP2012124026A (en) Nonaqueous electrolyte secondary battery
JP6859888B2 (en) Lithium-ion secondary battery and its manufacturing method
JP2018006289A (en) Nonaqueous electrolyte secondary battery
JP5290819B2 (en) Non-aqueous secondary battery
JP6812827B2 (en) Non-aqueous electrolyte and non-aqueous electrolyte battery using it
JP2010009898A (en) Nonaqueous secondary battery and nonaqueous secondary battery system
JP7228113B2 (en) Non-aqueous electrolyte secondary battery
JP2022523945A (en) Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery containing it
JPWO2014068931A1 (en) Nonaqueous electrolyte secondary battery
JP2013239374A (en) Lithium ion secondary battery and method for manufacturing the same
JP2013239375A (en) Lithium ion secondary battery and method for manufacturing the same
JP5741942B2 (en) Capacity recovery method for lithium secondary battery

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20090310

A711 Notification of change in applicant

Free format text: JAPANESE INTERMEDIATE CODE: A712

Effective date: 20110519

RD03 Notification of appointment of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7423

Effective date: 20110526

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120806

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20121003

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20121102

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20121219

A711 Notification of change in applicant

Free format text: JAPANESE INTERMEDIATE CODE: A712

Effective date: 20130121

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130220

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130313

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20140304