JP6876245B2 - Manufacturing method of non-aqueous electrolyte secondary battery - Google Patents

Manufacturing method of non-aqueous electrolyte secondary battery Download PDF

Info

Publication number
JP6876245B2
JP6876245B2 JP2016201953A JP2016201953A JP6876245B2 JP 6876245 B2 JP6876245 B2 JP 6876245B2 JP 2016201953 A JP2016201953 A JP 2016201953A JP 2016201953 A JP2016201953 A JP 2016201953A JP 6876245 B2 JP6876245 B2 JP 6876245B2
Authority
JP
Japan
Prior art keywords
negative electrode
libob
battery
positive electrode
aqueous electrolyte
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.)
Active
Application number
JP2016201953A
Other languages
Japanese (ja)
Other versions
JP2018063877A (en
Inventor
親平 近藤
親平 近藤
洋人 浅野
洋人 浅野
彰 神山
彰 神山
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.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
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 Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP2016201953A priority Critical patent/JP6876245B2/en
Publication of JP2018063877A publication Critical patent/JP2018063877A/en
Application granted granted Critical
Publication of JP6876245B2 publication Critical patent/JP6876245B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Secondary Cells (AREA)

Description

本発明は、非水電解液二次電池を製造する方法に関する。 The present invention relates to a method for producing a non-aqueous electrolyte secondary battery.

リチウムイオン二次電池その他の非水電解液二次電池は、既存の電池に比べ、小型、軽量かつ高エネルギー密度であって、出力密度に優れる。このため、近年、ハイブリッド車、電気自動車などの車両駆動用電源として好ましく用いられている。この種のリチウムイオン二次電池等の非水電解液二次電池では、充電の際に非水電解液の一部が分解され、負極活物質（例えば天然黒鉛粒子）の表面にその分解物からなる被膜、即ちＳＥＩ（Ｓｏｌｉｄ Ｅｌｅｃｔｒｏｌｙｔｅ Ｉｎｔｅｒｐｈａｓｅ）膜が形成され得る。ＳＥＩ膜は負極活物質を保護する役割を果たすが、非水電解液中の電荷担体（例えばリチウムイオン）を消費して形成されるため（即ち電荷担体がＳＥＩ膜中に固定されることによって、もはや電池容量に寄与できなくなる）、その量が多いと容量維持率を低下させる要因となる。かかる問題に対応すべく、ＳＥＩ膜に代えて負極活物質の表面に予め安定的な被膜を形成するために、所定の充電電位以上で分解し負極活物質の表面に被膜を生成する添加剤を非水電解液中に含ませることが行われている。例えば特許文献１には、添加剤としてリチウムビスオキサレートボレート（ＬｉＢＯＢ）を添加した非水電解液が開示されている。 Lithium-ion secondary batteries and other non-aqueous electrolyte secondary batteries are smaller, lighter, have higher energy density, and are superior in output density as compared with existing batteries. Therefore, in recent years, it is preferably used as a power source for driving a vehicle such as a hybrid vehicle or an electric vehicle. In a non-aqueous electrolyte secondary battery such as this type of lithium ion secondary battery, a part of the non-aqueous electrolyte is decomposed at the time of charging, and the decomposition product is formed on the surface of a negative electrode active material (for example, natural graphite particles). A film, that is, a SEI (Solid Electrolyte Interphase) film can be formed. The SEI film plays a role in protecting the negative electrode active material, but is formed by consuming charge carriers (for example, lithium ions) in the non-aqueous electrolyte solution (that is, by fixing the charge carriers in the SEI film). It can no longer contribute to the battery capacity), and if the amount is large, it becomes a factor that lowers the capacity retention rate. In order to deal with such a problem, in order to form a stable film on the surface of the negative electrode active material in advance instead of the SEI film, an additive that decomposes at a predetermined charging potential or higher to form a film on the surface of the negative electrode active material is used. It is used to be contained in a non-aqueous electrolyte solution. For example, Patent Document 1 discloses a non-aqueous electrolytic solution to which lithium bisoxalate borate (LiBOB) is added as an additive.

特開２００５−２５９５９２号公報Japanese Unexamined Patent Publication No. 2005-259592

ところで、非水電解液二次電池の電解液としては、一般にエチレンカーボネート等のカーボネート系溶媒に支持塩（例えばリチウム塩）を溶解させたものが用いられているが、近年、電池の更なる性能向上のために、カーボネート系溶媒よりも酸化され難いフッ素化溶媒（例えばフルオロエチレンカーボネート）を用いることが検討されている。
しかし、フッ素化溶媒は、カーボネート系溶媒に比べてＬｉＢＯＢが溶けにくい。そのため、フッ素化溶媒に可容量のＬｉＢＯＢを溶解させた二次電池は、負極に形成されるＬｉＢＯＢ由来の被膜の量が十分でなく、フッ素化溶媒が分解して容量維持率が低下するという問題があった。 By the way, as the electrolytic solution of the non-aqueous electrolyte secondary battery, a solvent in which a supporting salt (for example, a lithium salt) is dissolved in a carbonate solvent such as ethylene carbonate is generally used, but in recent years, further performance of the battery has been further improved. For improvement, it is considered to use a fluorinated solvent (for example, fluoroethylene carbonate) which is less likely to be oxidized than a carbonate-based solvent.
However, the fluorinated solvent is less soluble in LiBOB than the carbonate-based solvent. Therefore, the secondary battery in which the capacity of LiBOB is dissolved in the fluorinated solvent has a problem that the amount of the LiBOB-derived film formed on the negative electrode is not sufficient, the fluorinated solvent is decomposed, and the capacity retention rate is lowered. was there.

本発明はかかる点に鑑みてなされたものであり、その主な目的は、フッ素化溶媒を含む電解液を用いた非水電解液二次電池において、負極にＬｉＢＯＢ由来の被膜を十分に形成することで、容量維持率の低下を抑制し得る非水電解液二次電池の製造方法を提供することである。 The present invention has been made in view of this point, and a main object thereof is to sufficiently form a LiBOB-derived film on the negative electrode in a non-aqueous electrolyte secondary battery using an electrolytic solution containing a fluorination solvent. This is to provide a method for manufacturing a non-aqueous electrolyte secondary battery capable of suppressing a decrease in the capacity retention rate.

上記目的を実現するべく、本発明により、正極および負極を備える電極体と、フッ素化溶媒を含む電解液とを備える非水電解液二次電池の製造方法が提供される。この製造方法は、前記フッ素化溶媒に対する飽和溶解量を超える量のリチウムビスオキサレートボレート（ＬｉＢＯＢ）を添加した電解液を前記電極体とともに電池ケースに収容して電池組立体を構築する工程を包含する。また、前記電池組立体を加温しつつ充電することにより、該電池組立体を前記ＬｉＢＯＢの分解電位以上かつ前記フッ素化溶媒の分解電位未満の電圧域にて保持する工程（エージング工程）を包含する。かかる製造方法によれば、上記エージングの際に、負極の表面にＬｉＢＯＢ由来の成分を含む被膜が十分に形成される。したがって、充放電を繰り返しても容量維持率の低下がより少ない非水電解液二次電池を製造することができる。 In order to realize the above object, the present invention provides a method for producing a non-aqueous electrolyte secondary battery including an electrode body including a positive electrode and a negative electrode and an electrolytic solution containing a fluorinated solvent. This production method includes a step of constructing a battery assembly by accommodating an electrolytic solution to which an amount of lithium bisoxalate borate (LiBOB) added in an amount exceeding the saturated dissolution amount in the fluorinated solvent is contained in a battery case together with the electrode body. To do. Further, it includes a step (aging step) of holding the battery assembly in a voltage range equal to or higher than the decomposition potential of the LiBOB and lower than the decomposition potential of the fluorinated solvent by charging the battery assembly while heating it. To do. According to such a manufacturing method, a film containing a LiBOB-derived component is sufficiently formed on the surface of the negative electrode during the aging. Therefore, it is possible to manufacture a non-aqueous electrolytic solution secondary battery in which the capacity retention rate is less reduced even after repeated charging and discharging.

一実施形態に係る非水電解液二次電池の製造フローを示す図である。It is a figure which shows the manufacturing flow of the non-aqueous electrolyte secondary battery which concerns on one Embodiment. 一実施形態に係る非水電解液二次電池の模式断面図である。It is a schematic cross-sectional view of the non-aqueous electrolyte secondary battery which concerns on one Embodiment.

以下、適宜図面を参照しながら本発明の実施形態を説明する。なお、各図における寸法関係（長さ、幅、厚さ等）は実際の寸法関係を反映するものではない。また、本明細書において特に言及している事項以外の事柄であって本発明の実施に必要な事柄（例えば、正極および負極を備えた電極体の構成および製法、セパレータの構成および製法、電池（ケース）の形状等、電池の構築に係る一般的技術等）は、当該分野における従来技術に基づく当業者の設計事項として把握され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。 Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The dimensional relationships (length, width, thickness, etc.) in each figure do not reflect the actual dimensional relationships. In addition, matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention (for example, a constitution and a manufacturing method of an electrode body including a positive electrode and a negative electrode, a constitution and a manufacturing method of a separator, a battery (for example). The shape of the case), general technology related to battery construction, etc.) can be grasped as design items of those skilled in the art based on the prior art in the field. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art.

≪非水電解液二次電池の製造方法≫
ここで開示される非水電解液二次電池の製造方法は、図１に示すように、（ｉ）電池組立体構築工程と（ii）エージング工程とを包含する。なお（ｉ）は、電池組立体の製造方法としても把握され得る。各工程について順に説明する。なお、以下では、リチウムイオン二次電池を製造する場合を説明するが、本発明の適用対象を限定する意図ではない。 ≪Manufacturing method of non-aqueous electrolyte secondary battery≫
As shown in FIG. 1, the method for manufacturing a non-aqueous electrolyte secondary battery disclosed here includes (i) a battery assembly construction step and (ii) an aging step. Note that (i) can also be grasped as a method for manufacturing a battery assembly. Each step will be described in order. In the following, the case of manufacturing a lithium ion secondary battery will be described, but it is not intended to limit the application target of the present invention.

≪ｉ．電池組立体構築工程≫
電池組立体構築工程では、正極および負極を備える電極体と、フッ素化溶媒を含む非水電解液とを電池ケースに収容して電池組立体を構築する。 ≪i. Battery assembly construction process ≫
In the battery assembly construction step, a battery assembly is constructed by accommodating an electrode body having a positive electrode and a negative electrode and a non-aqueous electrolyte solution containing a fluorination solvent in a battery case.

＜正極＞
正極は、正極集電体上に正極活物質を含む正極活物質層が保持された構成を有する。正極を構成する正極集電体としては、従来と同様に、導電性の良好な金属からなる導電性部材が好ましく用いられる。導電性部材としては、例えばアルミニウムを用いることができる。 <Positive electrode>
The positive electrode has a configuration in which a positive electrode active material layer containing a positive electrode active material is held on a positive electrode current collector. As the positive electrode current collector constituting the positive electrode, a conductive member made of a metal having good conductivity is preferably used as in the conventional case. As the conductive member, for example, aluminum can be used.

正極活物質層は、正極活物質を含む。正極活物質としては、リチウムイオン二次電池の正極活物質として使用し得ることが知られている各種の材料を特に限定なく使用することができる。正極活物質の好適例としては、リチウムと少なくとも１種の遷移金属元素とを含むリチウム遷移金属化合物等が挙げられる。好ましい一態様では、正極活物質として、Ｌｉと、Ｎｉ、ＣｏおよびＭｎのうちの少なくとも１種と、を含むリチウム遷移金属複合酸化物が用いられる。なかでも好ましい一態様として、ＬｉとＭｎとを構成金属元素とするスピネル構造のリチウムマンガン複合酸化物が挙げられる。スピネル構造のリチウムマンガン複合酸化物を用いることで、ＳＯＣ（Ｓｔａｔｅ Ｏｆ Ｃｈａｒｇｅ）０％〜１００％の範囲における正極の作動上限電位を金属リチウム基準で４．３Ｖ以上（好ましくは４．３５Ｖ以上、より好ましくは４．６Ｖ、さらには４．９Ｖ以上）にすることができる。ここに開示される技術は、典型的にはＳＯＣ０％〜１００％の範囲における正極の作動上限電位が金属リチウム基準で４．３Ｖ以上５．５Ｖ以下（例えば４．９Ｖ以上５．２Ｖ以下）の非水電解液二次電池に好ましく適用され得る。 The positive electrode active material layer contains a positive electrode active material. As the positive electrode active material, various materials known to be usable as the positive electrode active material of the lithium ion secondary battery can be used without particular limitation. Preferable examples of the positive electrode active material include a lithium transition metal compound containing lithium and at least one transition metal element. In a preferred embodiment, a lithium transition metal composite oxide containing Li and at least one of Ni, Co and Mn is used as the positive electrode active material. Among them, a preferred embodiment is a lithium manganese composite oxide having a spinel structure containing Li and Mn as constituent metal elements. By using a lithium manganese composite oxide having a spinel structure, the operating upper limit potential of the positive electrode in the range of SOC (State Of Charge) 0% to 100% can be set to 4.3 V or more (preferably 4.35 V or more, preferably 4.35 V or more) based on metallic lithium. Preferably, it can be 4.6 V, more preferably 4.9 V or higher). The technique disclosed herein typically has a positive electrode operating upper limit potential in the range of 0% to 100% SOC of 4.3 V or more and 5.5 V or less (for example, 4.9 V or more and 5.2 V or less) based on metallic lithium. It can be preferably applied to non-aqueous electrolyte secondary batteries.

正極活物質層は、正極活物質の他に、必要に応じて導電材、結着材（バインダ）等の添加材を含有し得る。導電材としては、カーボン（例えばアセチレンブラック（ＡＢ））粉末やカーボンファイバー等の導電性粉末材料が好ましく用いられる。結着材としては、ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素系樹脂；スチレンブタジエンゴム（ＳＢＲ）等のゴム類；ポリフッ化ビニリデン（ＰＶｄＦ）などのハロゲン化ビニル樹脂；カルボキシメチルセルロース（ＣＭＣ）等のセルロース系ポリマー；が例示される。 The positive electrode active material layer may contain an additive such as a conductive material and a binder, if necessary, in addition to the positive electrode active material. As the conductive material, a conductive powder material such as carbon (for example, acetylene black (AB)) powder or carbon fiber is preferably used. Examples of the binder include fluororesins such as polytetrafluoroethylene (PTFE); rubbers such as styrene-butadiene rubber (SBR); vinyl halide resins such as polyvinylidene fluoride (PVdF); and carboxymethyl cellulose (CMC). Cellulose-based polymers; are exemplified.

＜負極＞
負極は、負極集電体上に負極活物質を含む負極活物質層が保持された構成を有する。負極を構成する負極集電体としては、従来と同様に、導電性の良好な金属からなる導電性部材が好ましく用いられる。導電性部材としては、例えば銅を用いることができる。 <Negative electrode>
The negative electrode has a structure in which a negative electrode active material layer containing a negative electrode active material is held on a negative electrode current collector. As the negative electrode current collector constituting the negative electrode, a conductive member made of a metal having good conductivity is preferably used as in the conventional case. As the conductive member, for example, copper can be used.

負極活物質層は、負極活物質を含む。負極活物質としては、従来からリチウムイオン二次電池に用いられる物質の一種または二種以上を特に限定なく使用することができる。負極活物質の一例としては、例えば炭素材料が挙げられる。炭素材料の代表例としては、グラファイトカーボン（黒鉛）、アモルファスカーボン等が挙げられる。 The negative electrode active material layer contains a negative electrode active material. As the negative electrode active material, one kind or two or more kinds of substances conventionally used for lithium ion secondary batteries can be used without particular limitation. An example of a negative electrode active material is a carbon material. Typical examples of carbon materials include graphite carbon (graphite), amorphous carbon and the like.

負極活物質層は、負極活物質の他に、必要に応じて結着材等の添加材を含有し得る。結着材としては各種のポリマー材料が挙げられる。例えば、水系の組成物または溶剤系の組成物に対して、正極活物質層に含有され得るものを好ましく用いることができる。そのような結着材は、結着材として用いられる他に増粘材、分散材その他の添加材として使用されることもあり得る。 The negative electrode active material layer may contain an additive such as a binder, if necessary, in addition to the negative electrode active material. Examples of the binder include various polymer materials. For example, for an aqueous composition or a solvent-based composition, those that can be contained in the positive electrode active material layer can be preferably used. In addition to being used as a binder, such binders may also be used as thickeners, dispersants and other additives.

＜電極体＞
電極体は、上記正極と上記負極とをセパレータを介して積層して形成されている。より詳細には、電極体は、正極活物質層と負極活物質層とがセパレータを介して重なり合う積層部を有している。この積層部は、正極活物質層と負極活物質層との間でセパレータを介して電荷担体（ここではリチウムイオン）の授受が行われる部分である。 <Electrode body>
The electrode body is formed by laminating the positive electrode and the negative electrode via a separator. More specifically, the electrode body has a laminated portion in which the positive electrode active material layer and the negative electrode active material layer are overlapped with each other via the separator. This laminated portion is a portion where a charge carrier (here, lithium ion) is transferred between the positive electrode active material layer and the negative electrode active material layer via a separator.

＜非水電解液＞
電池組立体の電池ケースに収容される非水電解液は、常温（例えば２５℃）で液状を呈する。好ましい一態様では、上記非水電解液は電池の使用環境下（例えば−２０〜＋６０℃の温度環境下）で常に液状を呈する。かかる非水電解液は、フッ素化溶媒と支持塩とリチウムビスオキサレートボレート（ＬｉＢＯＢ）とを含む。 <Non-aqueous electrolyte>
The non-aqueous electrolyte solution contained in the battery case of the battery assembly is liquid at room temperature (for example, 25 ° C.). In a preferred embodiment, the non-aqueous electrolyte solution always exhibits a liquid state in the battery usage environment (for example, in a temperature environment of -20 to + 60 ° C.). Such a non-aqueous electrolyte solution contains a fluorinated solvent, a supporting salt, and lithium bisoxalate borate (LiBOB).

支持塩としては、リチウムイオン二次電池の非水電解液に支持塩（リチウム塩）として使用し得ることが知られている各種の材料を特に限定なく使用することができる。支持塩の好適例としては、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣＦ３ＳＯ３、ＬｉＣ４Ｆ９ＳＯ３、Ｌｉ（ＣＦ３ＳＯ２）２Ｎ、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＳｉＦ６、ＬｉＣｌＯ４等が挙げられる。これらは１種を単独でまたは２種以上を組み合わせて用いることができる。 As the supporting salt, various materials known to be usable as the supporting salt (lithium salt) in the non-aqueous electrolyte solution of the lithium ion secondary battery can be used without particular limitation. Suitable examples of supporting salts include LiPF 6 , LiBF 4 , LiAsF 6 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , Li (CF 3 SO 2 ) 2 N, LiC (CF 3 SO 2 ) 3 , LiSiF 6 , LiClO 4 and the like. These can be used alone or in combination of two or more.

フッ素化溶媒としては、リチウムイオン二次電池の非水電解液に非水溶媒として使用し得ることが知られている各種の材料であって、かつ、一部がフッ素（Ｆ）で置換されているものを特に限定なく使用することができる。例えば、フッ素化溶媒として、フッ素化環状カーボネートやフッ素化鎖状カーボネートが好ましく用いられる。フッ素化環状カーボネートの例としては、モノフルオロエチレンカーボネート（ＭＦＥＣ）、ジフルオロエチレンカーボネート、４，４−ジフルオロエチレンカーボネート、トリフルオロエチレンカーボネート、パーフルオロエチレンカーボネート等が例示される。フッ素化鎖状カーボネートの例としては、フルオロメチルジフルオロメチルカーボネート、フルオロメチルメチルカーボネート、ジフルオロメチルメチルカーボネート、トリフルオロメチルメチルカーボネート、ビス（フルオロメチル）カーボネート、ビス（ジフルオロメチル）カーボネート、ビス（トリフルオロメチル）カーボネート、（２−フルオロエチル）メチルカーボネート、エチルフルオロメチルカーボネート、（２，２−ジフルオロエチル）メチルカーボネート、（２−フルオロエチル）フルオロメチルカーボネート、エチルジフルオロメチルカーボネート、（２，２，２−トリフルオロエチル）メチルカーボネート等が例示される The fluorination solvent is various materials known to be usable as a non-aqueous solvent in the non-aqueous electrolytic solution of a lithium ion secondary battery, and is partially substituted with fluorine (F). Anything that is available can be used without particular limitation. For example, as the fluorination solvent, a fluorinated cyclic carbonate or a fluorinated chain carbonate is preferably used. Examples of the fluorinated cyclic carbonate include monofluoroethylene carbonate (MFEC), difluoroethylene carbonate, 4,4-difluoroethylene carbonate, trifluoroethylene carbonate, perfluoroethylene carbonate and the like. Examples of fluorinated chain carbonates include fluoromethyldifluoromethylcarbonate, fluoromethylmethylcarbonate, difluoromethylmethylcarbonate, trifluoromethylmethylcarbonate, bis (fluoromethyl) carbonate, bis (difluoromethyl) carbonate, and bis (trifluoro). Methyl) carbonate, (2-fluoroethyl) methyl carbonate, ethylfluoromethyl carbonate, (2,2-difluoroethyl) methyl carbonate, (2-fluoroethyl) fluoromethyl carbonate, ethyldifluoromethyl carbonate, (2,2,2) -Trifluoroethyl) methyl carbonate and the like are exemplified.

フッ素化溶媒としては、上記フッ素化環状カーボネートと上記フッ素化鎖状カーボネートとの併用系が特に好ましい。例えば、フッ素化環状カーボネートとフッ素化鎖状カーボネートとの混合比は、体積基準で２０：８０〜４０：６０の範囲内であることが好ましい。 As the fluorination solvent, a combined system of the fluorinated cyclic carbonate and the fluorinated chain carbonate is particularly preferable. For example, the mixing ratio of the fluorinated cyclic carbonate and the fluorinated chain carbonate is preferably in the range of 20:80 to 40:60 on a volume basis.

電池組立体に収容される非水電解液は、リチウムビスオキサレートボレート（ＬｉＢＯＢ）を含む。ＬｉＢＯＢは、後述するエージングの際に負極に引き寄せられ、負極表面にＬｉＢＯＢ由来の成分を含んだ良質な被膜を形成する。 The non-aqueous electrolyte solution contained in the battery assembly contains lithium bisoxalate borate (LiBOB). The LiBOB is attracted to the negative electrode during aging, which will be described later, and forms a high-quality film containing a component derived from LiBOB on the surface of the negative electrode.

ここに開示される技術において、電池組立体に収容される非水電解液中のＬｉＢＯＢの添加量Ｘは、フッ素化溶媒に対する飽和溶解量Ｙを超える量であることが重要である。すなわち、電解液に過剰に添加されたＬｉＢＯＢは、その一部がフッ素化溶媒に溶けきらず、未溶解（固体のまま）で電解液中に存在する。なお、ここでいう「飽和溶解量」とは、添加時の温度（典型的には常温）においてフッ素化溶媒に可溶なＬｉＢＯＢの最大溶解量をいう。また、ＬｉＢＯＢの添加量Ｘは、特にことわりのない限り電解液１Ｌ中に含まれるＬｉＢＯＢのモル数を示すものとする。 In the technique disclosed herein, it is important that the addition amount X of LiBOB in the non-aqueous electrolyte solution contained in the battery assembly exceeds the saturated dissolution amount Y in the fluorinated solvent. That is, a part of LiBOB added excessively to the electrolytic solution is not completely dissolved in the fluorinated solvent and exists in the electrolytic solution in an undissolved state (as a solid). The "saturated dissolution amount" here means the maximum dissolution amount of LiBOB soluble in a fluorination solvent at the temperature at the time of addition (typically normal temperature). Further, the addition amount X of LiBOB shall indicate the number of moles of LiBOB contained in 1 L of the electrolytic solution unless otherwise specified.

ＬｉＢＯＢの添加量Ｘは、上記飽和溶解量Ｙよりも大きければよく（すなわちＸ＞Ｙ）特に制限されないが、飽和溶解量Ｙの凡そ２５倍以上（すなわち２５≦Ｘ／Ｙ）にすることが適当であり、好ましくは５０≦Ｘ／Ｙ、より好ましくは１００≦Ｘ／Ｙである。また、上記Ｘ／Ｙの上限は特に限定されないが、概ねＸ／Ｙ≦１５０、好ましくはＸ／Ｙ≦１２０であり得る。また、ＬｉＢＯＢの添加量Ｘは、飽和溶解量Ｙよりも０．０４ｍｏｌ／Ｌ以上（例えば０．０４８ｍｏｌ／Ｌ以上）大きいことが好ましく、０．０９ｍｏｌ／Ｌ以上（例えば０．０９８ｍｏｌ／Ｌ以上）大きいことがより好ましく、０．１９ｍｏｌ／Ｌ以上（例えば０．１９８ｍｏｌ／Ｌ以上）大きいことが特に好ましい。また、ＬｉＢＯＢの添加量Ｘから飽和溶解量Ｙを減じた値（すなわち、Ｘ−Ｙ）は、概ね０．４ｍｏｌ／Ｌ以下が適当であり、好ましくは０．３ｍｏｌ／Ｌ以下である。ＬｉＢＯＢの添加量Ｘは、例えば０．０５ｍｏｌ／Ｌ以上０．５ｍｏｌ／Ｌ未満（好ましくは０．０５ｍｏｌ／Ｌ以上０．３ｍｏｌ／Ｌ以下）であり得る。 The addition amount X of LiBOB may be larger than the saturated dissolution amount Y (that is, X> Y) and is not particularly limited, but it is appropriate to make it about 25 times or more (that is, 25 ≦ X / Y) of the saturated dissolution amount Y. It is preferably 50 ≦ X / Y, and more preferably 100 ≦ X / Y. The upper limit of X / Y is not particularly limited, but may be approximately X / Y ≦ 150, preferably X / Y ≦ 120. The addition amount X of LiBOB is preferably 0.04 mol / L or more (for example, 0.048 mol / L or more) larger than the saturated dissolution amount Y, and is 0.09 mol / L or more (for example, 0.098 mol / L or more). Larger is more preferable, and 0.19 mol / L or more (for example, 0.198 mol / L or more) is particularly preferable. The value obtained by subtracting the saturated dissolution amount Y from the addition amount X of LiBOB (that is, XY) is generally 0.4 mol / L or less, preferably 0.3 mol / L or less. The addition amount X of LiBOB can be, for example, 0.05 mol / L or more and less than 0.5 mol / L (preferably 0.05 mol / L or more and 0.3 mol / L or less).

電池組立体構築工程では、フッ素化溶媒に対する飽和溶解量を超える量のＬｉＢＯＢを添加した電解液を電極体とともに電池ケースに収容して電池組立体を構築する。電池ケースの材質は、アルミニウム等の金属材料、ポリフェニレンサルファイド等の樹脂材料であり得る。電池ケースの形状は特に限定されず、直方体、円筒形等であり得る。 In the battery assembly construction step, the battery assembly is constructed by accommodating the electrolytic solution containing LiBOB in an amount exceeding the saturated dissolution amount in the fluorinated solvent in the battery case together with the electrode body. The material of the battery case may be a metal material such as aluminum or a resin material such as polyphenylene sulfide. The shape of the battery case is not particularly limited, and may be a rectangular parallelepiped, a cylindrical shape, or the like.

＜ii．エージング工程＞
エージング工程では、上記電池組立体を加温しつつ充電を行うことにより、該電池組立体をＬｉＢＯＢの分解電位以上かつフッ素化溶媒の分解電位未満の電圧域にて保持する。典型的には、電池組立体の正極（正極端子）と負極（負極端子）の間に外部電源を接続し、ＬｉＢＯＢの分解電位以上かつフッ素化溶媒の分解電位未満となるような電圧範囲まで定電流で充電した後、その電圧を保つように定電圧充電する。これによって、負極表面にＬｉＢＯＢ由来の成分を含んだ良質な被膜が形成される。その際、フッ素化溶媒に対する飽和溶解量を超える量のＬｉＢＯＢが非水電解液に添加されているので、電解液のフッ素化溶媒に溶解したＬｉＢＯＢが被膜の形成に使用されて消費された後、未溶解のＬｉＢＯＢが電解液に新たに溶解する。そして、新たに溶解したＬｉＢＯＢにより負極に更なる被膜が形成される。すなわち、電解液のフッ素化溶媒に溶解したＬｉＢＯＢにより負極に被膜を形成した後も未溶解のＬｉＢＯＢにより負極に被膜が形成される。このことにより負極表面に十分な量の被膜が形成され、負極と非水電解液との界面が高度に安定化される（これ以降は、充放電を繰り返しても負極表面でのフッ素化溶媒の分解が抑制される）。したがって、長期間使用し続けても容量維持率の低下がより少ない非水電解液二次電池を製造することができる。 <Ii. Aging process>
In the aging step, by charging the battery assembly while heating it, the battery assembly is held in a voltage range equal to or higher than the decomposition potential of LiBOB and lower than the decomposition potential of the fluorinated solvent. Typically, an external power source is connected between the positive electrode (positive electrode terminal) and the negative electrode (negative electrode terminal) of the battery assembly, and the voltage range is set so as to be equal to or higher than the decomposition potential of LiBOB and lower than the decomposition potential of the fluorinated solvent. After charging with an electric current, it is charged with a constant voltage so as to maintain that voltage. As a result, a high-quality film containing a component derived from LiBOB is formed on the surface of the negative electrode. At that time, since an amount of LiBOB exceeding the saturated dissolution amount with respect to the fluorinated solvent is added to the non-aqueous electrolytic solution, the LiBOB dissolved in the fluorinated solvent of the electrolytic solution is used for forming the film and then consumed. The undissolved LiBOB is newly dissolved in the electrolytic solution. Then, a further film is formed on the negative electrode by the newly dissolved LiBOB. That is, even after the film is formed on the negative electrode by LiBOB dissolved in the fluorinated solvent of the electrolytic solution, the film is formed on the negative electrode by the undissolved LiBOB. As a result, a sufficient amount of film is formed on the surface of the negative electrode, and the interface between the negative electrode and the non-aqueous electrolyte solution is highly stabilized. Decomposition is suppressed). Therefore, it is possible to manufacture a non-aqueous electrolyte secondary battery having a smaller decrease in capacity retention rate even if it is used for a long period of time.

エージング工程における充電電圧（エージング保持電位）は、ＬｉＢＯＢが電気的に分解され、かつ、フッ素化溶媒が分解されないように、ＬｉＢＯＢの分解電位以上かつフッ素化溶媒の分解電位未満の電圧範囲に設定するとよい。一例として、フッ素化溶媒がフルオロエチレンカーボネート（ＦＥＣ）と（２，２，２‐トリフルオロエチル）メチルカーボネートとの併用系の場合、正負極端子間の電圧が概ね４．５Ｖ以上となるまで充電するとよい。エージング保持電位の上限は、フッ素化溶媒の分解電位以下であればよいが、ＬｉＢＯＢの酸化を抑制する観点からは、概ね４．７Ｖ未満（好ましくは４．６Ｖ以下）にすることが好ましい。かかる充電は、充電開始から電池電圧が所定の値に達するまで定電流充電する方式（ＣＣ充電）で行うことが好ましい。定電流充電時の充電レートは、通常１Ｃ以下、好ましくは０．１Ｃ〜０．２Ｃとするとよい。また、電池電圧が所定の値に達した後は、該電池電圧が保持されるように、定電圧充電することが好ましい。電池組立体を上記電圧範囲で保持する時間（エージング時間）は、負極表面に十分な量のＬｉＢＯＢ由来の被膜が形成されるまでの時間であればよく、例えば５時間〜２４０時間に設定され得る。 When the charging voltage (aging holding potential) in the aging step is set to a voltage range equal to or higher than the decomposition potential of LiBOB and lower than the decomposition potential of the fluorinated solvent so that the LiBOB is electrically decomposed and the fluorinated solvent is not decomposed. Good. As an example, when the fluorination solvent is a combination system of fluoroethylene carbonate (FEC) and (2,2,2-trifluoroethyl) methyl carbonate, charging is performed until the voltage between the positive and negative terminals becomes approximately 4.5 V or more. It is good to do. The upper limit of the aging holding potential may be not less than the decomposition potential of the fluorinated solvent, but from the viewpoint of suppressing the oxidation of LiBOB, it is preferably less than about 4.7 V (preferably 4.6 V or less). Such charging is preferably performed by a method of constant current charging (CC charging) from the start of charging until the battery voltage reaches a predetermined value. The charging rate during constant current charging is usually 1C or less, preferably 0.1C to 0.2C. Further, after the battery voltage reaches a predetermined value, it is preferable to charge the battery at a constant voltage so that the battery voltage is maintained. The time (aging time) for holding the battery assembly in the above voltage range may be any time until a sufficient amount of LiBOB-derived film is formed on the surface of the negative electrode, and can be set to, for example, 5 hours to 240 hours. ..

エージング工程における加温（エージング）温度は、室温（例えば２５℃）を上回る温度域であれば特に制限されないが、例えば、電池組立体を４０℃以上（例えば４０〜６０℃）の高温環境下で保持することが好ましい。電池組立体を昇温して保持する手段としては、例えば温度制御恒温槽や赤外線ヒーター等を用いることができる。このように高温で所定の期間電池を保存することで、未溶解のＬｉＢＯＢの液中への溶解が促進されるとともに、上記充電時に負極表面に形成された被膜の成長が促進される。結果、例えば電池を室温で保存した場合に比べて、より多くの被膜を形成することができる。このため、上述の耐久性向上の効果が更に高いレベルで実現される。 The heating (aging) temperature in the aging step is not particularly limited as long as it is in a temperature range above room temperature (for example, 25 ° C.), but for example, the battery assembly is placed in a high temperature environment of 40 ° C. or higher (for example, 40 to 60 ° C.). It is preferable to hold it. As a means for raising and holding the temperature of the battery assembly, for example, a temperature-controlled constant temperature bath, an infrared heater, or the like can be used. By storing the battery at a high temperature for a predetermined period of time in this way, the dissolution of the undissolved LiBOB in the liquid is promoted, and the growth of the film formed on the surface of the negative electrode during the charging is promoted. As a result, more coatings can be formed than, for example, when the battery is stored at room temperature. Therefore, the above-mentioned effect of improving durability is realized at a higher level.

上記エージング工程の後、常法によりコンディショニング工程等を行うことにより、ここで開示される非水電解液二次電池を製造することができる。 By performing a conditioning step or the like by a conventional method after the aging step, the non-aqueous electrolyte secondary battery disclosed here can be manufactured.

以下、本実施形態の製造方法により得られた非水電解液二次電池の概略構成として、扁平に捲回された電極体（捲回電極体）と非水電解液とを扁平な直方体形状の容器（電池ケース）に収容した形態の非水電解液二次電池を例として説明するが、本発明をかかる実施形態に限定することを意図したものではない。 Hereinafter, as a schematic configuration of the non-aqueous electrolyte secondary battery obtained by the production method of the present embodiment, a flatly wound electrode body (wound electrode body) and a non-aqueous electrolyte solution have a flat rectangular shape. A non-aqueous electrolyte secondary battery in a form housed in a container (battery case) will be described as an example, but the present invention is not intended to be limited to such an embodiment.

図２は、非水電解液二次電池１００の断面構造を模式的に示す縦断面図である。非水電解液二次電池１００は、長尺状の正極シート１０と長尺状の負極シート２０とが長尺状のセパレータシート４０を介して扁平に捲回された形態の電極体（捲回電極体）８０が、図示しない非水電解液とともに扁平な箱型形状の電池ケース５０内に収容された構成を有する。 FIG. 2 is a vertical cross-sectional view schematically showing a cross-sectional structure of the non-aqueous electrolyte secondary battery 100. The non-aqueous electrolyte secondary battery 100 is an electrode body (turning) in which a long positive electrode sheet 10 and a long negative electrode sheet 20 are flatly wound via a long separator sheet 40. The electrode body) 80 has a structure in which a non-aqueous electrolyte solution (not shown) is housed in a flat box-shaped battery case 50.

電池ケース５０は、上端が開放された扁平な直方体形状（箱型）の電池ケース本体５２と、その開口部を塞ぐ蓋体５４とを備えている。電池ケース５０の上面（すなわち蓋体５４）には、捲回電極体８０の正極と電気的に接続する外部接続用の正極端子７０、および捲回電極体８０の負極と電気的に接続する負極端子７２が設けられている。蓋体５４にはまた、従来の非水電解液二次電池の電池ケースと同様に、電池ケース５０の内部で発生したガスをケース５０の外部に排出するための安全弁５５が備えられている。 The battery case 50 includes a flat rectangular parallelepiped (box-shaped) battery case main body 52 having an open upper end, and a lid 54 that closes the opening. On the upper surface of the battery case 50 (that is, the lid 54), a positive electrode terminal 70 for external connection that is electrically connected to the positive electrode of the wound electrode body 80, and a negative electrode that is electrically connected to the negative electrode of the wound electrode body 80. A terminal 72 is provided. The lid 54 is also provided with a safety valve 55 for discharging the gas generated inside the battery case 50 to the outside of the case 50, similarly to the battery case of the conventional non-aqueous electrolyte secondary battery.

捲回電極体８０は、組み立てる前段階において、長尺シート状の正極（正極シート）１０と、長尺シート状の負極（負極シート）２０とを備えている。正極シート１０は、長尺状の正極集電体と、その少なくとも一方の表面（典型的には両面）に長手方向に沿って形成された正極活物質層１４とを備えている。負極シート２０は、長尺状の負極集電体と、その少なくとも一方の表面（典型的には両面）に長手方向に沿って形成された負極活物質層２４とを備えている。また、正極活物質層１４と負極活物質層２４との間には、両者の直接接触を防ぐ絶縁層が配置されている。ここでは、上記絶縁層として２枚の長尺シート状のセパレータ４０を使用している。このような捲回電極体８０は、例えば、正極シート１０、セパレータシート４０、負極シート２０、セパレータシート４０の順に重ね合わせた積層体を長手方向に捲回し、得られた捲回体を側面方向から押圧して拉げさせることによって扁平形状に成形することにより作製することができる。 The wound electrode body 80 includes a long sheet-shaped positive electrode (positive electrode sheet) 10 and a long sheet-shaped negative electrode (negative electrode sheet) 20 at a stage before assembly. The positive electrode sheet 10 includes a long positive electrode current collector and a positive electrode active material layer 14 formed along the longitudinal direction on at least one surface (typically both sides) of the positive electrode current collector. The negative electrode sheet 20 includes a long negative electrode current collector and a negative electrode active material layer 24 formed on at least one surface (typically both sides) of the negative electrode current collector along the longitudinal direction. Further, an insulating layer for preventing direct contact between the positive electrode active material layer 14 and the negative electrode active material layer 24 is arranged. Here, two long sheet-shaped separators 40 are used as the insulating layer. In such a wound electrode body 80, for example, a laminated body in which a positive electrode sheet 10, a separator sheet 40, a negative electrode sheet 20, and a separator sheet 40 are laminated in this order is wound in the longitudinal direction, and the obtained wound body is wound in the lateral direction. It can be produced by forming it into a flat shape by pressing it from the surface and pulling it.

捲回電極体８０の捲回軸方向の一の端部から他の一の端部に向かう方向として規定される幅方向において、その中央部分には、正極集電体の表面に形成された正極活物質層１４と負極集電体の表面に形成された負極活物質層２４とが重なり合って密に積層された捲回コア部分が形成されている。また、捲回電極体８０の捲回軸方向の両端部では、正極シート１０の正極活物質層非形成部および負極シート２０の負極活物質層非形成部が、それぞれ捲回コア部分から外方にはみ出ている。そして、正極側はみ出し部分には正極集電体が、負極側はみ出し部分には負極集電体が、それぞれ付設され、正極端子７０および上記負極端子７２とそれぞれ電気的に接続されている。 In the width direction defined as the direction from one end of the winding electrode body 80 in the winding axis direction to the other end, a positive electrode formed on the surface of the positive electrode current collector is located in the central portion thereof. A wound core portion is formed in which the active material layer 14 and the negative electrode active material layer 24 formed on the surface of the negative electrode current collector are overlapped and densely laminated. Further, at both ends of the wound electrode body 80 in the winding axis direction, the positive electrode active material layer non-forming portion of the positive electrode sheet 10 and the negative electrode active material layer non-forming portion of the negative electrode sheet 20 are outward from the winding core portion, respectively. It sticks out. A positive electrode current collector is attached to the protruding portion on the positive electrode side, and a negative electrode current collector is attached to the protruding portion on the negative electrode side, and the positive electrode terminal 70 and the negative electrode terminal 72 are electrically connected to each other.

ここに開示される非水電解液二次電池は各種用途に利用可能であるが、上記製造方法により得られる効果により、長期にわたって電池容量が維持され得る。このような非水電解液二次電池は、例えば、ハイブリッド自動車（ＨＶ）やプラグインハイブリッド自動車（ＰＨＶ）、電気自動車（ＥＶ）等の車両に搭載されるモーター用の動力源（駆動用電源）として好ましく利用され得る。したがって、本構成によると、ここに開示されるいずれかの非水電解液二次電池（複数の電池が接続された組電池の形態であり得る。）を搭載した車両が提供される。 Although the non-aqueous electrolyte secondary battery disclosed herein can be used for various purposes, the battery capacity can be maintained for a long period of time due to the effect obtained by the above-mentioned production method. Such a non-aqueous electrolyte secondary battery is, for example, a power source (driving power source) for a motor mounted on a vehicle such as a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or an electric vehicle (EV). Can be preferably used as. Therefore, according to this configuration, a vehicle equipped with any of the non-aqueous electrolyte secondary batteries disclosed herein (which may be in the form of an assembled battery in which a plurality of batteries are connected) is provided.

次に、本発明に関するいくつかの実施例を説明するが、本発明を実施例に示すものに限定することを意図したものではない。 Next, some examples of the present invention will be described, but it is not intended to limit the present invention to those shown in the examples.

正極は、次のようにして作製した。まず、正極活物質としてのスピネル構造リチウムニッケルマンガン複合酸化物粉末（ＬｉＮｉ０．５Ｍｎ１．５Ｏ４、平均粒径１０μｍ）と、導電材としてのＡＢと、バインダとしてのＰＶｄＦとを、正極活物質：導電材：バインダの質量比が８７：１０：３となるようにＮＭＰ中で混合して、正極活物質層形成用組成物を調製した。この正極活物質層形成用組成物を長尺シート状のアルミニウム箔（正極集電体）の片面に塗布して乾燥することにより、正極集電体の片面に正極活物質層が設けられた正極を作製した。 The positive electrode was prepared as follows. First, a spinel-structured lithium nickel-manganese composite oxide powder (LiNi 0.5 Mn 1.5 O 4 , average particle size 10 μm) as a positive electrode active material, AB as a conductive material, and PVdF as a binder are used as positive electrodes. A composition for forming a positive electrode active material layer was prepared by mixing in NMP so that the mass ratio of active material: conductive material: binder was 87:10: 3. By applying this composition for forming a positive electrode active material layer to one side of a long sheet-shaped aluminum foil (positive electrode current collector) and drying it, a positive electrode having a positive electrode active material layer provided on one side of the positive electrode current collector is provided. Was produced.

負極は、次のようにして作製した。まず、負極活物質としての天然黒鉛（平均粒径２０μｍ）と、バインダとしてのＳＢＲと、増粘剤としてのＣＭＣとを、負極活物質：バインダ：増粘剤の質量比が９８：１：１となるように水に分散させて負極活物質層形成用組成物を調製した。この負極活物質層形成用組成物を長尺シート状の銅箔（負極集電体）の片面に塗布して乾燥することにより、負極集電体の片面に負極活物質層が設けられた負極を作製した。 The negative electrode was prepared as follows. First, natural graphite (average particle size 20 μm) as the negative electrode active material, SBR as the binder, and CMC as the thickener are mixed, and the mass ratio of the negative electrode active material: binder: thickener is 98: 1: 1. A composition for forming a negative electrode active material layer was prepared by dispersing in water so as to be. By applying this composition for forming a negative electrode active material layer to one side of a long sheet-shaped copper foil (negative electrode current collector) and drying it, a negative electrode having a negative electrode active material layer provided on one side of the negative electrode current collector is provided. Was produced.

セパレータとしては、ポリプロピレン／ポリエチレン／ポリプロピレンの三層構造の微多孔質フィルム（ＰＰ／ＰＥ／ＰＰフィルム）の基材からなるセパレータを用意した。 As the separator, a separator made of a base material of a microporous film (PP / PE / PP film) having a three-layer structure of polypropylene / polyethylene / polypropylene was prepared.

上記で用意した正極、負極およびセパレータを用いて、電池組立体を構築した。すなわち、セパレータを間に介して、上記で作製した正極と負極とを、両電極の互いの活物質層が対向するように積層して電極体を作製した。次いで、この電極体を非水電解液とともにラミネート製の袋状電池容器に収容し、封口して電池組立体を構築した。 A battery assembly was constructed using the positive electrode, the negative electrode and the separator prepared above. That is, an electrode body was prepared by laminating the positive electrode and the negative electrode prepared above with a separator in between so that the active material layers of both electrodes face each other. Next, this electrode body was housed in a bag-shaped battery container made of laminate together with a non-aqueous electrolytic solution, and sealed to construct a battery assembly.

電池組立体に収容される非水電解液としては、フルオロエチレンカーボネート（ＦＥＣ）と（２，２，２‐トリフルオロエチル）メチルカーボネートとを３：７の体積比で含む混合溶媒（非水溶媒）に、支持塩としてのＬｉＰＦ６を約１ｍｏｌ／リットルの濃度で含有させ、さらにＬｉＢＯＢを表１に示す添加量Ｘ（ｍｏｌ／Ｌ）で添加したものを用いた。なお、上記混合溶媒に対する室温（約２５℃）でのＬｉＢＯＢの飽和溶解量は０．００２ｍｏｌ／Ｌである。 The non-aqueous electrolyte solution contained in the battery assembly is a mixed solvent (non-aqueous solvent) containing fluoroethylene carbonate (FEC) and (2,2,2-trifluoroethyl) methyl carbonate in a volume ratio of 3: 7. ) Contained LiPF 6 as a supporting salt at a concentration of about 1 mol / liter, and LiBOB was further added in an addition amount X (mol / L) shown in Table 1. The saturated dissolution amount of LiBOB at room temperature (about 25 ° C.) with respect to the mixed solvent is 0.002 mol / L.

＜エージング工程＞
上記電池組立体に対し、表１に示すエージング温度下において、０．２Ｃの定電流にて表１に示す電圧（エージング保持電位）に到達するまで充電し、その後、そのエージング保持電位で定電圧となるように電流を暫時下げながら充電を継続し、所定時間保持した。その後、コンディショニング処理を行うことにより評価用ラミネートセルを構築した。このラミネートセルの設計容量は１４ｍＡｈである。 <Aging process>
The battery assembly is charged at the aging temperature shown in Table 1 with a constant current of 0.2 C until the voltage (aging holding potential) shown in Table 1 is reached, and then the constant voltage is used at the aging holding potential. Charging was continued while the current was lowered for a while so as to be, and the battery was held for a predetermined time. Then, a laminating cell for evaluation was constructed by performing a conditioning treatment. The design capacity of this laminate cell is 14 mAh.

例１〜８では、ＬｉＢＯＢの添加量Ｘ、エージング工程におけるエージング温度、エージング保持電位が異なる。例１〜８のラミネートセルについて、使用したＬｉＢＯＢの添加量Ｘ、エージング温度およびエージング保持電位を表１に纏めて示す。 In Examples 1 to 8, the addition amount X of LiBOB, the aging temperature in the aging step, and the aging holding potential are different. For the laminated cells of Examples 1 to 8, the addition amount X of LiBOB used, the aging temperature, and the aging holding potential are summarized in Table 1.

Figure 0006876245
Figure 0006876245

＜初期容量の測定＞
各例のラミネートセルにつき、温度２５℃で、以下の手順１、２にしたがって初期容量を測定した。
（手順１）１／５Ｃの定電流充電によって４．９Ｖに到達後、電流が１／５０Ｃとなるまで定電圧充電し、満充電状態とした。
（手順２）１／５Ｃの定電流放電によって、３．５Ｖに到達するまで定電圧放電した。
そして、手順２における放電容量を初期容量とした。 <Measurement of initial capacity>
The initial volume of the laminated cell of each example was measured at a temperature of 25 ° C. according to the following procedures 1 and 2.
(Procedure 1) After reaching 4.9 V by constant current charging at 1 / 5C, constant voltage charging was performed until the current became 1 / 50C to bring the battery into a fully charged state.
(Procedure 2) A constant voltage discharge of 1 / 5C was performed until the voltage reached 3.5V.
Then, the discharge capacity in step 2 was set as the initial capacity.

＜高温サイクル試験＞
各例のラミネートセルのそれぞれに対し、６０℃において、２Ｃの定電流で４．９Ｖに到達するまで充電した後、２Ｃの定電流で３．５Ｖに到達するまで放電を行う充放電サイクルを２００回連続して繰り返す充放電サイクル試験を行った。
そして、上記充放電サイクル試験前における初期容量（ラミネートセルの初期容量）と、充放電サイクル試験後における電池容量とから容量維持率を算出した。ここで、サイクル試験後における電池容量は、前述した初期容量と同じ手順で測定した。また、上記容量維持率は、「サイクル試験後の電池容量／サイクル試験前の初期容量」×１００により求めた。結果を表１に示す。 <High temperature cycle test>
Each of the laminated cells of each example is charged at 60 ° C. with a constant current of 2C until it reaches 4.9V, and then discharged until it reaches 3.5V with a constant current of 2C. 200 charge / discharge cycles are performed. A charge / discharge cycle test was performed by repeating the charge / discharge cycle test repeatedly.
Then, the capacity retention rate was calculated from the initial capacity (initial capacity of the laminated cell) before the charge / discharge cycle test and the battery capacity after the charge / discharge cycle test. Here, the battery capacity after the cycle test was measured by the same procedure as the initial capacity described above. The capacity retention rate was determined by "battery capacity after cycle test / initial capacity before cycle test" x 100. The results are shown in Table 1.

表１に示すように、ＬｉＢＯＢを添加しなかった例５のセルは、高温サイクル後における容量維持率が８３％を下回った。また、飽和溶解量と同量のＬｉＢＯＢを電池組立体の電解液に添加した例６のセルは、ＬｉＢＯＢ由来の被膜形成が不足していたため、容量維持率向上効果が僅かであった。エージング工程で電池組立体を加温しなかった例７のセルは、ＬｉＢＯＢの溶解速度または被膜形成速度が上がらず、被膜が十分に形成されなかったため、容量維持率向上効果が僅かであった。エージング工程でエージング保持電位を４．３Ｖとした例８のセルは、ＬｉＢＯＢの分解が不十分であり、ＬｉＢＯＢ由来の被膜形成が不足していたため、容量維持率向上効果が僅かであった。これに対し、例１〜４のセルは、負極表面に十分な量のＬｉＢＯＢ由来の被膜が形成されたため、例５〜８のセルに比べて容量維持率で良好な結果が得られた。以上の結果から、フッ素化溶媒に対する飽和溶解量を超える量のＬｉＢＯＢを電池組立体の電解液に添加し、電池組立体を加温すると共に、ＬｉＢＯＢの分解電位以上かつフッ素化溶媒の分解電位未満の電圧域にてエージングを行うことにより、電池容量を長期にわたって維持発揮することができる（高耐久性な）非水電解液二次電池が実現されることが確認された。 As shown in Table 1, the cell of Example 5 to which LiBOB was not added had a capacity retention rate of less than 83% after the high temperature cycle. Further, in the cell of Example 6 in which the same amount of LiBOB as the saturated dissolved amount was added to the electrolytic solution of the battery assembly, the film formation derived from LiBOB was insufficient, so that the effect of improving the capacity retention rate was slight. In the cell of Example 7 in which the battery assembly was not heated in the aging step, the dissolution rate or the film forming rate of LiBOB did not increase, and the film was not sufficiently formed, so that the effect of improving the capacity retention rate was slight. In the cell of Example 8 in which the aging holding potential was set to 4.3 V in the aging step, the decomposition of LiBOB was insufficient and the film formation derived from LiBOB was insufficient, so that the effect of improving the capacity retention rate was slight. On the other hand, in the cells of Examples 1 to 4, since a sufficient amount of LiBOB-derived film was formed on the surface of the negative electrode, better results were obtained in terms of capacity retention rate as compared with the cells of Examples 5 to 8. From the above results, an amount of LiBOB exceeding the saturated dissolution amount in the fluorinated solvent was added to the electrolytic solution of the battery assembly to heat the battery assembly, and at the same time, it was equal to or higher than the decomposition potential of LiBOB and less than the decomposition potential of the fluorinated solvent. It was confirmed that a non-aqueous electrolyte secondary battery capable of maintaining and exhibiting the battery capacity for a long period of time (highly durable) is realized by aging in the voltage range of.

以上、本発明の具体例を詳細に説明したが、これらは例示にすぎず、特許請求の範囲を限定するものではない。ここに開示される発明には上述の具体例を様々に変形、変更したものが含まれ得る。 Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The invention disclosed herein may include various modifications and modifications of the above-mentioned specific examples.

１０ 正極シート
１４ 正極活物質層
２０ 負極シート
２４ 負極活物質層
４０ セパレータシート
５０ 電池ケース
１００ 非水電解液二次電池 10 Positive electrode sheet 14 Positive electrode active material layer 20 Negative electrode sheet 24 Negative electrode active material layer 40 Separator sheet 50 Battery case 100 Non-aqueous electrolyte secondary battery

Claims (2)

正極および負極を備える電極体と、フッ素化溶媒を含む電解液とを備える非水電解液二次電池の製造方法であって、
前記フッ素化溶媒に対する飽和溶解量の２５倍以上のリチウムビスオキサレートボレート（ＬｉＢＯＢ）を添加した電解液を前記電極体とともに電池ケースに収容して電池組立体を構築する工程；および、
前記電池組立体を加温しつつ充電することにより、該電池組立体を前記ＬｉＢＯＢの分解電位以上かつ前記フッ素化溶媒の分解電位未満の電圧域にて保持するエージング工程；を包含する、非水電解液二次電池の製造方法。 A method for manufacturing a non-aqueous electrolyte secondary battery including an electrode body including a positive electrode and a negative electrode and an electrolytic solution containing a fluorination solvent.
A step of constructing a battery assembly by accommodating an electrolytic solution containing 25 times or more of the saturated dissolved amount of lithium bisoxalate borate (LiBOB) in the fluorinated solvent in a battery case together with the electrode body;
A non-aqueous aging step of holding the battery assembly in a voltage range equal to or higher than the decomposition potential of the LiBOB and lower than the decomposition potential of the fluorinated solvent by charging the battery assembly while heating it. A method for manufacturing an electrolytic solution secondary battery. 前記電解液に含まれる溶媒がフッ素化溶媒のみから成る、請求項１に記載の非水電解液二次電池の製造方法。 The method for producing a non-aqueous electrolytic solution secondary battery according to claim 1, wherein the solvent contained in the electrolytic solution is only a fluorinated solvent.
JP2016201953A 2016-10-13 2016-10-13 Manufacturing method of non-aqueous electrolyte secondary battery Active JP6876245B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016201953A JP6876245B2 (en) 2016-10-13 2016-10-13 Manufacturing method of non-aqueous electrolyte secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016201953A JP6876245B2 (en) 2016-10-13 2016-10-13 Manufacturing method of non-aqueous electrolyte secondary battery

Publications (2)

Publication Number Publication Date
JP2018063877A JP2018063877A (en) 2018-04-19
JP6876245B2 true JP6876245B2 (en) 2021-05-26

Family

ID=61966831

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016201953A Active JP6876245B2 (en) 2016-10-13 2016-10-13 Manufacturing method of non-aqueous electrolyte secondary battery

Country Status (1)

Country Link
JP (1) JP6876245B2 (en)

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01124970A (en) * 1987-11-10 1989-05-17 Hitachi Maxell Ltd Lithium secondary battery
JP2014022335A (en) * 2012-07-23 2014-02-03 Asahi Kasei Corp Electrolyte for nonaqueous electricity storage device
JP2014032777A (en) * 2012-08-01 2014-02-20 Toyota Motor Corp Method of manufacturing nonaqueous secondary battery
JP6032474B2 (en) * 2012-09-11 2016-11-30 トヨタ自動車株式会社 Non-aqueous electrolyte secondary battery and manufacturing method thereof
JP6135219B2 (en) * 2013-03-18 2017-05-31 株式会社豊田自動織機 Electrolytic solution and lithium ion secondary battery provided with the same
JP2016519400A (en) * 2013-04-04 2016-06-30 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニーＥ．Ｉ．Ｄｕ Ｐｏｎｔ Ｄｅ Ｎｅｍｏｕｒｓ Ａｎｄ Ｃｏｍｐａｎｙ Non-aqueous electrolyte composition
JP6044453B2 (en) * 2013-05-24 2016-12-14 株式会社豊田自動織機 Method for manufacturing power storage device
JP6274526B2 (en) * 2014-09-17 2018-02-07 トヨタ自動車株式会社 Nonaqueous electrolyte secondary battery and manufacturing method thereof
JP2016076411A (en) * 2014-10-08 2016-05-12 トヨタ自動車株式会社 Method for manufacturing nonaqueous electrolyte secondary battery

Also Published As

Publication number Publication date
JP2018063877A (en) 2018-04-19

Similar Documents

Publication Publication Date Title
JP5924552B2 (en) Non-aqueous electrolyte secondary battery and manufacturing method thereof
JP5787196B2 (en) Lithium ion secondary battery
JP6044842B2 (en) Method for producing non-aqueous electrolyte secondary battery
JP5783433B2 (en) Lithium ion secondary battery
JP4453049B2 (en) Manufacturing method of secondary battery
WO2016020737A1 (en) Nonaqueous electrolyte secondary battery
US10199689B2 (en) Nonaqueous electrolyte secondary battery
JP2013182712A (en) Nonaqueous electrolyte secondary battery and manufacturing method thereof
US20150214571A1 (en) Lithium secondary battery and method for producing same
KR101757978B1 (en) Nonaqueous electrolyte secondary battery and method of manufacturing the same, and separator for nonaqueous electrolyte secondary battery
JP6390902B2 (en) Non-aqueous electrolyte secondary battery
JP6304198B2 (en) Non-aqueous electrolyte secondary battery and method for producing non-aqueous electrolyte secondary battery
JP6770701B2 (en) Power storage element
CN109119629B (en) Non-aqueous electrolyte secondary battery
JP2021044138A (en) Nonaqueous electrolyte secondary battery
JP6722384B2 (en) Lithium ion secondary battery
JP2020080255A (en) Non-aqueous electrolyte secondary battery
JP6876245B2 (en) Manufacturing method of non-aqueous electrolyte secondary battery
JP6778396B2 (en) Non-aqueous electrolyte secondary battery
JP6731152B2 (en) Method for manufacturing non-aqueous electrolyte secondary battery
JP6323723B2 (en) Non-aqueous electrolyte secondary battery manufacturing method and battery assembly
CN114583244B (en) Lithium ion secondary battery
JP6731155B2 (en) Non-aqueous electrolyte secondary battery
JP2017054736A (en) Electrolytic solution for lithium ion secondary battery, and method for manufacturing lithium ion secondary battery
JP2017041416A (en) Lithium ion secondary battery and manufacturing method of the same

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20181218

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20190807

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20190822

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20191021

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20200319

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200513

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20201029

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20210125

C60 Trial request (containing other claim documents, opposition documents)

Free format text: JAPANESE INTERMEDIATE CODE: C60

Effective date: 20210125

A911 Transfer of reconsideration by examiner before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20210128

C21 Notice of transfer of a case for reconsideration by examiners before appeal proceedings

Free format text: JAPANESE INTERMEDIATE CODE: C21

Effective date: 20210204

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: 20210325

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20210407

R151 Written notification of patent or utility model registration

Ref document number: 6876245

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151