JP2007026752A - Manufacturing method of non-aqueous electrolytic solution secondary battery - Google Patents

Manufacturing method of non-aqueous electrolytic solution secondary battery Download PDF

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JP2007026752A
JP2007026752A JP2005204158A JP2005204158A JP2007026752A JP 2007026752 A JP2007026752 A JP 2007026752A JP 2005204158 A JP2005204158 A JP 2005204158A JP 2005204158 A JP2005204158 A JP 2005204158A JP 2007026752 A JP2007026752 A JP 2007026752A
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JP4899361B2 (en
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Toru Matsui
徹 松井
Hidekazu Hiratsuka
秀和 平塚
Shinji Arimoto
真司 有元
Toshihide Murata
年秀 村田
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Panasonic Holdings Corp
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    • 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
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    • Y02E60/10—Energy storage using batteries
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    • 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

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Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolytic solution secondary battery which has excellent reliability with less internal short-circuit by easily removing conductive foreign matters mixed into a positive electrode. <P>SOLUTION: In a manufacturing method of the non-aqueous electrolytic solution secondary battery, an active material in a non-charged state and the active material in a chargeed state are contained in the positive electrode in an electrode plate group before contacted with an electrolytic solution. In the manufacturing method of a second invention, an additive reduced on a negative electrode at a potential of 1.5 V vs. Li/Li<SP>+</SP>or more is mixed into the electrolytic solution, and only the positive electrode is charged at a first-time charging. Furthermore, in the manufacturing method of a third invention, a compound reduced at the potential of 1.5 V vs. Li/Li<SP>+</SP>or more is mixed into the negative electrode, and only the positive electrode is charged at a first-time charging. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、非水電解液二次電池の製造法に関し、特に、内部短絡の少ない非水電解液二次電池を提供するための製造法に関する。   The present invention relates to a method for producing a non-aqueous electrolyte secondary battery, and more particularly, to a production method for providing a non-aqueous electrolyte secondary battery with few internal short circuits.

ＬｉＣｏＯ2などの遷移金属酸化物を活物質とする正極と黒鉛などの炭素材料を活物質とする負極を組み合わせた非水電解液二次電池は、高エネルギー密度を有することから、ノートパソコン、携帯電話、ビデオカメラ、小型ゲーム機器などに幅広く使用されている。そして、機器の高機能化や長時間作動に対応するため、さらに、高エネルギー密度化を図ることが望まれている。 Non-aqueous electrolyte secondary batteries that combine a positive electrode that uses a transition metal oxide such as LiCoO 2 as an active material and a negative electrode that uses a carbon material such as graphite as an active material have high energy density. Widely used in telephones, video cameras, small game machines, etc. And in order to respond | correspond to the high functionalization and long-time operation | movement of an apparatus, it is desired to aim at high energy density further.

非水電解液二次電池のエネルギー密度を高めていくには、高容量の正極および負極活物質を開発する必要がある一方で、これらの活物質を電池ケース内に多く充填するために他の電池部材の体積を減らす必要がある。ここで他の電池部材の体積を減らすとは、例えば、集電体を薄く短くしたり、ケース厚みを薄くしたり、また、セパレータを短く薄くすることである。   In order to increase the energy density of non-aqueous electrolyte secondary batteries, it is necessary to develop high-capacity positive and negative electrode active materials. On the other hand, in order to fill a large amount of these active materials in the battery case, It is necessary to reduce the volume of the battery member. Here, reducing the volume of other battery members means, for example, making the current collector thin and short, making the case thickness thin, and making the separator short and thin.

セパレータを薄くすることは、単に、非水電解液二次電池のエネルギー密度を高めるだけでなく、電池の内部抵抗を小さくすることができ、高負荷での充放電を容易にすることができる。しかし、一方で、電池内での正極と負極の短絡が起きやすくなり、電池電圧が不安定になる可能性が大きくなる。   Thinning the separator not only increases the energy density of the non-aqueous electrolyte secondary battery, but also reduces the internal resistance of the battery and facilitates charge / discharge at high loads. However, on the other hand, a short circuit between the positive electrode and the negative electrode easily occurs in the battery, and the possibility that the battery voltage becomes unstable increases.

正極と負極の電池内での短絡（以下、内部短絡という）は、薄くなったセパレータが裂けることで正極と負極が、直接、接触することもありうるが、多くの場合は、電池内に紛れ込んだ導電性異物によって内部短絡が引き起こされる。ここで、導電性異物による内部短絡のメカニズムは２通りある。ひとつは、導電性異物がそのままの形でセパレータを貫通することで、内部短絡が起きるものである。他のメカニズムは、正極に紛れ込んだ導電性異物が正極の高い電位によって電解液中にイオンとして溶解し、そのイオンが電位の低い負極に導電性金属として局所析出し、正極に向かって成長することで、内部短絡が起きるものである。   A short circuit in the battery between the positive electrode and the negative electrode (hereinafter referred to as “internal short circuit”) may cause direct contact between the positive electrode and the negative electrode by tearing the thinned separator, but in many cases, it is mixed into the battery. An internal short circuit is caused by the conductive foreign matter. Here, there are two mechanisms of internal short circuit due to the conductive foreign matter. One is that an internal short circuit occurs when the conductive foreign material penetrates the separator as it is. The other mechanism is that the conductive foreign matter infiltrated into the positive electrode dissolves as an ion in the electrolyte due to the high potential of the positive electrode, and the ion is locally deposited as a conductive metal on the negative electrode with a low potential and grows toward the positive electrode. Therefore, an internal short circuit occurs.

導電性異物は、さまざまな工程で紛れ込む。当初から活物質自体を合成する原料粉に含まれるだけでなく、活物質の粉砕工程、電極ペーストの調製や塗工工程、電極をスリットする工程、電極とセパレータを一体化して巻き取る工程などで使用される機械からこぼれ落ちる。電極やセパレータに付着した導電性異物は、物理的な手法で取り除くことができる。例えば、エアーブローや吸引、磁石による磁力吸着、研磨テープによる拭き取り、などである。また、電極スリットの刃をセラミックスに変更することで、異物を非導電性にすることもできる。しかし、電極内に潜り込んだ導電性異物は、これらの物理的手法によって取り除くことは困難である。   Conductive foreign matter is mixed in in various processes. It is not only included in the raw material powder that synthesizes the active material itself from the beginning, but also in the active material pulverization process, electrode paste preparation and coating process, electrode slitting process, electrode and separator integrated winding process, etc. Spills from the machine used. The conductive foreign matter adhering to the electrode and the separator can be removed by a physical method. For example, air blow, suction, magnetic force adsorption with a magnet, wiping with a polishing tape, and the like. Further, the foreign matter can be made non-conductive by changing the blade of the electrode slit to ceramics. However, it is difficult to remove the conductive foreign material that has entered the electrode by these physical methods.

そこで、さまざまな検査法や電気化学的手法が提案されている。   Therefore, various inspection methods and electrochemical methods have been proposed.

例えば、非水電解液二次電池を４．０Ｖ以上に充電し、正極に紛れ込んだ金属粉の溶解を促進させることで、微少な内部短絡による品質不良品を選別するという検査法が提案されている。（特許文献１参照）
また、電気化学的手法としては、正極と負極とを一体化して組み込む前に、正極中に紛れ込んだ導電性異物をあらかじめ除去する方法が提案されている。すなわち、正極を形成
後、電解液槽に浸漬させて予備充電を行い、導電性異物を溶解した後、乾燥させる。次に、この正極と負極を一体化して極板群をつくり、電池ケースに収納して、電解液を注入するというものである。（特許文献２参照）
特開２００３−３６８８７号公報 特開２００３−４５４９６号公報 ババ ヤスノリ（Ｙａｓｕｎｏｒｉ Ｂａｂａ），オカダ シゲト（Ｓｈｉｇｅｔｏ Ｏｋａｄａ），ヤマキ ジュンイチ（Ｊｕｎ−ｉｃｈｉ Ｙａｍａｋｉ）、リチウムイオン電池用ＬｉxＣｏＯ2正極の熱安定性（Ｔｈｅｒｍａｌ ｓｔａｂｉｌｉｔｙ ｏｆ ＬｉxＣｏＯ2 ｃａｔｈｏｄｅ ｆｏｒ ｌｉｔｈｉｕｍ ｉｏｎ ｂａｔｔｅｒｙ） ソリッド・ステイト・イオニクス（Ｓｏｌｉｄ Ｓｔａｔｅ Ｉｏｎｉｃｓ），オランダ、エルセヴィーアー・ビー・ヴィ（Ｅｌｓｅｖｉｅｒ Ｂ．Ｖ．）、２００２年、第１４８巻、３１１頁〜３１６頁 For example, an inspection method has been proposed in which a non-aqueous electrolyte secondary battery is charged to 4.0 V or more and the dissolution of metal powder mixed into the positive electrode is promoted to select defective products due to minute internal short circuits. Yes. (See Patent Document 1)
In addition, as an electrochemical method, a method is proposed in which conductive foreign matters that have been mixed in the positive electrode are removed in advance before the positive electrode and the negative electrode are integrated and integrated. That is, after forming the positive electrode, it is immersed in an electrolytic solution tank and precharged, and after the conductive foreign matter is dissolved, it is dried. Next, the positive electrode and the negative electrode are integrated to form a group of electrode plates, housed in a battery case, and an electrolyte solution is injected. (See Patent Document 2)
JP 2003-36887 A JP 2003-45496 A Thermal stability of LixCoO2 positive electrode for lithium-ion batteries (Thermal stability of LixCoO2) Solid State Ionics), The Netherlands, Elsevier BV (2002), 148, 311-316.

特許文献１のような検査法では、正極中に紛れ込んだ導電性異物は電池の充電により溶解させ除去することができるが、電位が低くなった負極上に、溶解により生成したイオンが局所析出して成長し、やがては、内部短絡が起きるようになる。   In the inspection method as described in Patent Document 1, conductive foreign matters mixed in the positive electrode can be dissolved and removed by charging the battery. However, ions generated by the dissolution are locally deposited on the negative electrode having a low potential. Over time, an internal short circuit occurs.

特許文献２ような電気化学的手法では、正極をいったん電解液槽中で予備充電して乾燥させるという工程が繁雑である。すなわち、電源設備の設置だけでなく予備充電条件の設定決定と管理、非水電解液槽中のイオン濃度管理や水分の混入防止、乾燥させた正極に残存している電解質塩と周辺環境に存在する水分との反応など、正極の品質を良好に保つことが難しい。   In the electrochemical method as in Patent Document 2, the process of precharging and drying the positive electrode once in an electrolyte bath is complicated. In other words, not only the installation of power supply facilities but also the determination and management of precharge conditions, the control of ion concentration in nonaqueous electrolyte baths, the prevention of moisture contamination, and the presence of electrolyte salts remaining on the dried cathode and the surrounding environment It is difficult to maintain good quality of the positive electrode such as reaction with moisture.

本発明はこのような課題を鑑みてなされたものであり、正極中に紛れ込んだ導電性異物を容易に取り除き、内部短絡の少ない信頼性に優れた非水電解液二次電池を提供することを目的とする。   The present invention has been made in view of such a problem, and provides a non-aqueous electrolyte secondary battery excellent in reliability with few internal shorts by easily removing conductive foreign matters mixed in the positive electrode. Objective.

上記の課題を解決するために、本発明の非水電解液二次電池の製造法は、リチウムイオンを吸蔵した活物質からなる正極と、リチウムイオンを吸蔵していない活物質からなる負極とを、セパレータをはさんで一体化して極板群を形成した後、非水電解液を注液し、初回の充電後に放置を行う非水電解液二次電池の製造法において、前記正極には、さらに充電状態の活物質が混合されており、前記注液後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うものである。   In order to solve the above problems, a method for producing a non-aqueous electrolyte secondary battery of the present invention includes a positive electrode made of an active material that occludes lithium ions and a negative electrode made of an active material that does not occlude lithium ions. In the method of manufacturing a non-aqueous electrolyte secondary battery in which a non-aqueous electrolyte solution is injected after the separator is integrated to form an electrode plate group, and left after the first charge, the positive electrode includes: Further, an active material in a charged state is mixed, and after pouring, the negative electrode is left in a state where lithium ions are not occluded.

また、第二の発明の製造法は、前記非水電解液には、さらに１．５Ｖ ｖｓ．Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤が混合されており、初回の充電は、前記負極にリチウムイオンを吸蔵していない状態で正極電位を変化させる充電であり、その後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うものである。 Further, in the production method of the second invention, the non-aqueous electrolyte further includes 1.5 V vs. Additives that are reduced on the negative electrode at a potential of Li / Li + or higher are mixed, and the initial charge is a charge that changes the positive electrode potential in a state where lithium ions are not occluded in the negative electrode, and then The negative electrode is left in a state where lithium ions are not occluded.

さらに、第三の発明の製造法は、前記負極には、さらに１．５Ｖ ｖｓ．Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤が混合されており、初回の充電は、前記負極にリチウムイオンを吸蔵していない状態で正極電位を変化させる充電であり、その後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うものである。 Furthermore, in the production method of the third invention, the negative electrode further includes 1.5 V vs. Additives that are reduced on the negative electrode at a potential of Li / Li + or higher are mixed, and the initial charge is a charge that changes the positive electrode potential in a state where lithium ions are not occluded in the negative electrode, and then The negative electrode is left in a state where lithium ions are not occluded.

本発明によって内部短絡が抑制できる理由を以下のように推察しており、正極活物質がＬｉＣｏＯ2であり、負極活物質が黒鉛である場合を用いて説明する。なお、活物質が１００％の充電状態であるとは、ＬｉＣｏＯ2ではＬｉ0．5ＣｏＯ2となった状態、黒鉛では
ＬｉＣ6となった状態をいう。 The reason why the internal short circuit can be suppressed by the present invention is presumed as follows, and will be described using the case where the positive electrode active material is LiCoO 2 and the negative electrode active material is graphite. Note that the active material is 100% charged in LiCoO 2 with Li 0 . 5 This refers to the state of CoO 2 and the state of LiC 6 in graphite.

ＬｉＣｏＯ2などの遷移金属酸化物を活物質とする正極と黒鉛などの炭素材料を活物質とする負極を組み合わせた非水電解液二次電池において、初めて電解液を注入した時点では、正極の電位はおよそ３．２Ｖ ｖｓ． Ｌｉ／Ｌｉ+であり、負極の電位はおよそ３．０Ｖ ｖｓ． Ｌｉ／Ｌｉ+である。この時点では、正極に紛れ込んだ鉄や銅や真ちゅうなどの導電性異物は溶解しない。 In a non-aqueous electrolyte secondary battery in which a positive electrode using a transition metal oxide such as LiCoO 2 as an active material and a negative electrode using a carbon material such as graphite as an active material are combined, when the electrolyte is injected for the first time, the potential of the positive electrode Is approximately 3.2 V vs.. Li / Li + , and the potential of the negative electrode is about 3.0 V vs. Li / Li + . At this point, conductive foreign matters such as iron, copper, and brass mixed in the positive electrode do not dissolve.

第一の発明の製造法は、正極に充電状態の活物質を混合しておくというものである。電解液を初めて注入した時点では、ＬｉＣｏＯ2などを活物質とする正極は未充電状態である。この正極に充電状態のＬｉ0．5ＣｏＯ2を少量混合しておくと、電解液に触れた時点で正極の電位はおよそ３．９Ｖ ｖｓ． Ｌｉ／Ｌｉ+にまで上昇する。このような高電位で放置すると、正極に紛れ込んだ導電性異物は容易にイオンとして溶解し始める。ここで、正極全体の電位が３．９Ｖ であるので、正極表面に付着している導電性異物だけでなく、正極板内に潜り込んだ異物まで溶解することができる。一方、注液後の放置では、負極はおよそ３．０Ｖ ｖｓ． Ｌｉ／Ｌｉ+の高い電位を保ったままである。したがって、正極で生成した導電性異物のイオンは、負極上でただちに析出せず、時間とともに電池の内部全体に拡散する。導電性異物のイオンは、その後、電池が充電されて負極の電位がきわめて低くなって初めて、負極上に析出する。導電性異物のイオンが負極上に析出する時点では、イオンはひろく拡散してしまっているので、負極上の特定の場所に局所析出することはない。このため、内部短絡を抑制することができる。 The manufacturing method of 1st invention mixes the active material of a charged state with a positive electrode. At the time when the electrolytic solution is injected for the first time, the positive electrode using LiCoO 2 or the like as an active material is in an uncharged state. This positive electrode is charged with Li 0 . 5 When a small amount of CoO 2 is mixed, the potential of the positive electrode reaches about 3.9 V vs. It rises to Li / Li + . When left at such a high potential, the conductive foreign matter mixed in the positive electrode starts to dissolve as ions easily. Here, since the electric potential of the whole positive electrode is 3.9V, it can melt | dissolve not only the electroconductive foreign material adhering to the positive electrode surface but the foreign material which sunk in the positive electrode plate. On the other hand, when left after injection, the negative electrode is approximately 3.0 V vs. The high potential of Li / Li + is maintained. Therefore, the ions of the conductive foreign matter generated at the positive electrode do not immediately deposit on the negative electrode, but diffuse throughout the battery over time. Thereafter, the conductive foreign ions are deposited on the negative electrode only after the battery is charged and the potential of the negative electrode becomes very low. At the time when the ions of the conductive foreign matter are deposited on the negative electrode, the ions are widely diffused, so that they are not locally deposited at a specific location on the negative electrode. For this reason, an internal short circuit can be suppressed.

第二の発明の製造法は、電解液中に１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤を混合し、初回の充電で正極のみを充電するものである。ＬｉＣｏＯ2などの金属遷移酸化物は、未充電状態ではおよそ３．２Ｖ ｖｓ． Ｌｉ／Ｌｉ+の電位を示すが、約０．１％充電するだけでおよそ３．９Ｖ ｖｓ． Ｌｉ／Ｌｉ+の電位にまで到達する。したがって、正極に紛れ込んだ導電性異物はイオンとなって、正極より溶解する。一方、負極材料である黒鉛は、約０．１％の充電で、およそ１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+にまで低下する。このため、導電性異物のイオンは、負極上で直ちに還元され析出する。この時点での析出はイオンが電池内部全体に拡散しておらず局所析出となるので、内部短絡が起きやすくなる。ここで、１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤を電解液に加えておくと、黒鉛負極の電位が１．５Ｖに下がる前に添加剤の還元反応が起きるので、黒鉛負極には、リチウムイオンが吸蔵されること無く、未充電状態のままである。したがって、充電を停止する、つまり外部から印加していた電位を停止すると、再び、負極の電位は３Ｖ近くにまで上昇する。正極に紛れ込んだ導電性異物の溶解速度は大きくはないので、瞬間的な充電であれば、正極の電位が３．９Ｖ ｖｓ． Ｌｉ／Ｌｉ+であり、負極の電位がおよそ３Ｖであるような状態をつくり出せる。よって、その後の放置で、導電性異物が溶解して生じたイオンは電池内部にひろく拡散することになるので、負極上への局所析出が起きず、内部短絡が抑制される。 In the production method of the second invention, 1.5 V vs. An additive that is reduced on the negative electrode at a potential of Li / Li + or higher is mixed, and only the positive electrode is charged by the first charge. Metal transition oxides such as LiCoO 2 are approximately 3.2 V vs. approximately uncharged. Although it shows a potential of Li / Li + , it is approximately 3.9 V vs. only by charging about 0.1%. A potential of Li / Li + is reached. Therefore, the conductive foreign matter mixed into the positive electrode becomes ions and dissolves from the positive electrode. On the other hand, graphite, which is a negative electrode material, is approximately 1.5 V vs. approximately 0.1% charge. It falls to Li / Li + . For this reason, the ions of the conductive foreign matter are immediately reduced and deposited on the negative electrode. The deposition at this point is not locally diffused inside the battery but is locally deposited, so that an internal short circuit is likely to occur. Here, 1.5V vs. If an additive that is reduced on the negative electrode at a potential equal to or higher than Li / Li + is added to the electrolyte, a reduction reaction of the additive occurs before the potential of the graphite negative electrode drops to 1.5 V. The lithium ions are not occluded and remain in an uncharged state. Therefore, when the charging is stopped, that is, when the potential applied from the outside is stopped, the potential of the negative electrode rises again to near 3V. Since the rate of dissolution of the conductive foreign material mixed into the positive electrode is not high, the potential of the positive electrode is 3.9 V vs. It is possible to create a state where Li / Li + and the potential of the negative electrode is about 3V. Therefore, since the ions generated by dissolving the conductive foreign substance in the subsequent standing are diffused into the battery, local precipitation on the negative electrode does not occur, and internal short circuit is suppressed.

第三の発明の製造法は、負極中に１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+以上の電位において還元される化合物を混合し、初回の充電で正極のみを充電するものである。上述したように、正極および負極の電位を高くすることで、正極に紛れ込んだ導電性異物の溶解を促進し、一方、溶解で生じたイオンを負極上に局所析出することなく拡散させることができる。負極中に１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+ 以上の電位で還元される化合物を混合しておくと、第二の発明と同様に、瞬間的な充電を行うことで、その後の放置時に、正極の電位を３．９Ｖ ｖｓ． Ｌｉ／Ｌｉ+にし、負極の電位をおよそ３Ｖにすることができる。したがって、導電性異物が溶解して生じたイオンは電池内部にひろく拡散することになるので、負極上への局所析出が起きず、内部短絡が抑制される。 The manufacturing method of 3rd invention is 1.5V vs. in a negative electrode. A compound that is reduced at a potential of Li / Li + or higher is mixed, and only the positive electrode is charged by the first charge. As described above, by increasing the potentials of the positive electrode and the negative electrode, it is possible to promote the dissolution of the conductive foreign matter mixed in the positive electrode, and to diffuse ions generated by the dissolution without locally depositing on the negative electrode. . 1.5V vs. in the negative electrode. When a compound to be reduced at a potential of Li / Li + or higher is mixed, the potential of the positive electrode is set to 3.9 V vs. VS. Li / Li + can be used, and the potential of the negative electrode can be about 3V. Therefore, ions generated by dissolving the conductive foreign substance diffuse widely inside the battery, so that local precipitation on the negative electrode does not occur and internal short circuit is suppressed.

本発明の製造法によれば、電池、特に、正極板内に潜り込んだ導電性異物を簡便に溶解し、溶解したイオンの負極上への局所析出を抑制することができる。したがって、内部短絡の少ない非水電解液二次電池を得ることができる。   According to the production method of the present invention, it is possible to easily dissolve the conductive foreign matter that has entered the battery, particularly the positive electrode plate, and to suppress local precipitation of the dissolved ions on the negative electrode. Therefore, a nonaqueous electrolyte secondary battery with few internal short circuits can be obtained.

本発明の製造法では、ＬｉＣｏＯ2、ＬｉＮｉＯ2、ＬｉＭｎ2Ｏ4などの遷移金属酸化物を正極活物質とし、黒鉛、難黒鉛化炭素材料、Ｌｉ4Ｔ5Ｏ12、リチウムと合金化可能な金属材料などを負極活物質とし、充放電によって正極と負極の間でリチウムイオンを行き来させる非水電解液二次電池を対象とすることが好ましい。この理由は、正極の電位を高く設定することで、導電性異物の溶解を促進することができるからである。非水電解液に使用される溶媒は、環状カーボネートであるエチレンカーボネート（以下、ＥＣと略記）、プロピレンカーボネート、ブチレンカーボネート、環状エステルであるγ−ブチロラクトン、鎖状カーボネートであるジメチルカーボネート、エチルメチルカーボネート（以下、ＥＭＣと略記）、ジエチルカーボネートなどである。非水電解液は、これらの非水溶媒に、リチウムヘキサフルオロホスフェート（ＬｉＰＦ6）、リチウムテトラフルオロボレート、リチウムパークロレート、リチウムビス［トリフルオロメタンスルホニル］イミドなどのリチウム塩を溶解して調製される。 In the production method of the present invention, transition metal oxides such as LiCoO 2 , LiNiO 2 , LiMn 2 O 4 can be used as a positive electrode active material, and can be alloyed with graphite, non-graphitizable carbon material, Li 4 T 5 O 12 , and lithium. It is preferable to target a non-aqueous electrolyte secondary battery in which a metal material or the like is used as a negative electrode active material and lithium ions are transferred between the positive electrode and the negative electrode by charging and discharging. This is because dissolution of the conductive foreign matter can be promoted by setting the potential of the positive electrode high. Solvents used in the non-aqueous electrolyte include cyclic carbonate ethylene carbonate (hereinafter abbreviated as EC), propylene carbonate, butylene carbonate, cyclic ester γ-butyrolactone, chain carbonate dimethyl carbonate, and ethyl methyl carbonate. (Hereinafter abbreviated as EMC), diethyl carbonate, and the like. Nonaqueous electrolytes are prepared by dissolving lithium salts such as lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate, lithium perchlorate, and lithium bis [trifluoromethanesulfonyl] imide in these nonaqueous solvents. .

未充電状態の正極に充電状態の活物質を少量含ませる第一の発明の製造法において、もっとも簡便な方法は、元々リチウムを含まず高電位で放電できるＶ2Ｏ5などを混合することである。ただし、Ｖ2Ｏ5の場合には、その電位はおよそ３．４Ｖ ｖｓ． Ｌｉ／Ｌｉ+であるので、溶解できる導電性異物は銅などに限られる。 In the manufacturing method of the first invention in which a small amount of the active material in the charged state is contained in the uncharged positive electrode, the simplest method is to mix V 2 O 5 that does not originally contain lithium and can be discharged at a high potential. is there. However, in the case of V 2 O 5 , the potential is about 3.4 V vs. approx. Since it is Li / Li + , the conductive foreign matter that can be dissolved is limited to copper or the like.

そこで、ほとんどの導電性異物を溶解するには、化学的に充電された正極活物質を準備すればよい。例えば、ＬｉＣｏＯ2の場合、常法にしたがってＬｉ2ＣＯ3とＣｏ2Ｏ3を混合して焼成し、ＬｉＣｏＯ2を調製する。次に、例えば非特許文献１に記載の従来公知の方法に基づいて、ＬｉＣｏＯ2から化学的にリチウムを引き抜くことで、Ｌｉ0.46ＣｏＯ2を得る。このようにして調製したＬｉＣｏＯ2にＬｉ0．46ＣｏＯ2を少量混合し、さらにカーボンブラックなどの導電性助剤と結着剤を混合することで、少量充電された充電状態の正極を作製することができる。 Therefore, in order to dissolve most conductive foreign substances, a chemically charged positive electrode active material may be prepared. For example, in the case of LiCoO 2 , Li 2 CO 3 and Co 2 O 3 are mixed and fired according to a conventional method to prepare LiCoO 2 . Next, Li 0.46 CoO 2 is obtained by chemically extracting lithium from LiCoO 2 based on a conventionally known method described in Non-Patent Document 1, for example. LiCoO 2 prepared in this manner was added to Li 0 . By mixing a small amount of 46 CoO 2 and further mixing a conductive auxiliary agent such as carbon black and a binder, a positive electrode charged in a small amount can be produced.

同様に、ＬｉＭｎ2Ｏ4の充電状態であるλ−ＭｎＯ2を得るには、ＬｉＭｎ2Ｏ4を２Ｎの希硫酸でｐＨが２になるまで洗浄すればよい。なお、Ｌｉ0．46ＣｏＯ2やλ−ＭｎＯ2は、リチウム参照極に対して、４Ｖ以上の電位を有するため、混合する充電状態の正極活物質として好ましい。 Similarly, to obtain the lambda-MnO 2 is a state of charge of the LiMn 2 O 4, may be cleaned LiMn 2 O 4 to pH 2 with 2N dilute sulfuric acid. Note that Li 0 . 46 CoO 2 and λ-MnO 2 have a potential of 4 V or more with respect to the lithium reference electrode, and are therefore preferable as a positive electrode active material in a charged state to be mixed.

混合する未充電状態の正極活物質と充電状態の正極活物質が同じである必要はない。ＬｉＣｏＯ2にＬｉ0．46ＣｏＯ2を混合してもよいし、ＬｉＣｏＯ2とλ−ＭｎＯ2を混合してもよい。充電状態の活物質の混合量は、未充電状態の正極活物質が、電解液と接触後、充電状態の活物質との反応によって充電状態となり、導電性異物が溶解する電位に達するように決定される。その量は、たかだか、活物質全体の数重量％である。これ以上に混合しても導電性異物の溶解に対する効果は同じであり、むしろ、電池の容量が減少するため好ましくない。 The uncharged positive electrode active material and the charged positive electrode active material to be mixed need not be the same. LiCoO 2 and Li 0 . 46 CoO 2 may be mixed, or LiCoO 2 and λ-MnO 2 may be mixed. The amount of the active material in the charged state is determined so that the positive active material in the uncharged state becomes a charged state by the reaction with the active material in the charged state after contact with the electrolyte, and reaches a potential at which the conductive foreign matter dissolves. Is done. The amount is at most several weight percent of the total active material. Even if it mixes more than this, the effect with respect to melt | dissolution of an electroconductive foreign material is the same, Rather, since the capacity | capacitance of a battery reduces, it is unpreferable.

第二の発明の製造法は、電解液中に１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤を混合することであり、例えば、リチウムシクロヘキサフルオロプロパン−１，３−ビス［スルホニル］イミド、リチウムビス［オキサレート（２−）］ボレート、リチウムトリフルオロメチルトリフルオロボレート、リチウムペンタフル
オロエチルトリフルオロボレート、リチウムヘプタフルオロプロピルトリフルオロボレート、リチウムトリス［ペンタフルオロエチル］トリフルオロホスフェートなどのリチウム塩があげられる。これらの塩のアニオンは、強い電子吸引基を有することから、およそ、２Ｖ ｖｓ． Ｌｉ／Ｌｉ+ の電位で還元分解が起きるので、初回の充電で負極にＬｉが吸蔵されることは無く、負極の電位が１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+以下になる状態を回避できる。添加剤の混合量は、導電性異物の溶解が起きやすくなるまで正極の電位が上昇した時、すべての添加剤が還元分解されないように調整する。このような調整によって初回充電後の負極電位は下がることはないので、異物の溶解によって生じたイオンが負極上で局所析出しない。 In the production method of the second invention, 1.5 V vs. An additive that is reduced on the negative electrode at a potential of Li / Li + or higher, for example, lithium cyclohexafluoropropane-1,3-bis [sulfonyl] imide, lithium bis [oxalate (2-)] Examples thereof include lithium salts such as borate, lithium trifluoromethyl trifluoroborate, lithium pentafluoroethyl trifluoroborate, lithium heptafluoropropyl trifluoroborate, and lithium tris [pentafluoroethyl] trifluorophosphate. The anions of these salts have strong electron withdrawing groups, so approximately 2 V vs. Since reductive decomposition occurs at a potential of Li / Li + , Li is not occluded in the negative electrode by the first charge, and the potential of the negative electrode is 1.5 V vs. It is possible to avoid a state where Li / Li + or less. The mixing amount of the additive is adjusted so that all additives are not reduced and decomposed when the potential of the positive electrode is increased until the dissolution of the conductive foreign matter is likely to occur. Such adjustment does not lower the negative electrode potential after the first charge, so that ions generated by the dissolution of the foreign matter are not locally deposited on the negative electrode.

強い電子吸引基を有するアニオンと同様な効果を示す添加剤としては、環状酸無水物である、無水イタコン酸、無水グルタコン酸、無水グルタル酸、無水こはく酸、無水ジグリコール酸、無水シトラコン酸、無水ジフェン酸、ナフタル酸無水物、無水ピロメリト酸、無水フタル酸、無水フタロン酸、無水マレイン酸、無水メリト酸があげられる。また、スクシンイミド、グルタルイミド、フタルイミドなどの酸イミドにおける活性水素を、メチル基などに置換した誘導体や、カリウムなどに交換した金属塩でもよい。さらに、２−スルホ安息香酸環状無水物やジフェニルジスルホンなどのスルホン化合物も使用できる。   As an additive having the same effect as an anion having a strong electron-withdrawing group, it is a cyclic acid anhydride, itaconic anhydride, glutaconic anhydride, glutaric anhydride, succinic anhydride, diglycolic anhydride, citraconic anhydride, Examples thereof include diphenic anhydride, naphthalic anhydride, pyromellitic anhydride, phthalic anhydride, phthalonic anhydride, maleic anhydride, and melittic anhydride. Alternatively, a derivative obtained by substituting the active hydrogen in an acid imide such as succinimide, glutarimide, and phthalimide with a methyl group, or a metal salt exchanged with potassium or the like may be used. Furthermore, sulfone compounds such as 2-sulfobenzoic acid cyclic anhydride and diphenyldisulfone can also be used.

第三の発明の製造法は、負極中に１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+ 以上の電位において還元される化合物を混合することであり、例えば、ＭｎＯ2、Ｖ6Ｏ13、ＬｉＶ3Ｏ8、ＴｉＳ2、ＭｏＳ2、ＭｏＳ3、Ｃｒ3Ｏ8、Ｆｅ2（ＳＯ4）3、ＦｅＦ3、アニオンドープされたポリアニリンやポリピロールなどがあげられる。これらの化合物の混合量は、電池の充電によって導電性異物の溶解が起きやすくなるまで正極の電位が上昇するが、その時、化合物がすべて還元分解されないように決定される。このように混合量を調整して充電を停止すると、負極の電位は下がっていないので、異物の溶解によって生じたイオンが負極上で局所析出しないようになる。負極に混合する化合物の量は、正極活物質の式量にも依存するが、たかだか、正極活物質全体の数重量％である。 The manufacturing method of 3rd invention is 1.5V vs. in a negative electrode. A compound that is reduced at a potential of Li / Li + or higher, for example, MnO 2 , V 6 O 13 , LiV 3 O 8 , TiS 2 , MoS 2 , MoS 3 , Cr 3 O 8 , Fe 2 (SO 4 ) 3 , FeF 3 , anion-doped polyaniline, polypyrrole, and the like. The mixing amount of these compounds is determined so that the potential of the positive electrode rises until the conductive foreign matter is easily dissolved by charging the battery, but at that time, all the compounds are not reduced and decomposed. When charging is stopped by adjusting the mixing amount in this manner, the potential of the negative electrode is not lowered, so that ions generated by the dissolution of the foreign matter are not locally deposited on the negative electrode. The amount of the compound mixed in the negative electrode depends on the formula amount of the positive electrode active material, but is at most several weight% of the total positive electrode active material.

以下に、本発明に関する実施例として、未充電状態の活物質に充電状態の活物質を混合して、正極に紛れ込んだ導電性異物の溶解を促進する例を示す。   In the following, as an embodiment relating to the present invention, an example in which an active material in a charged state is mixed with an active material in an uncharged state to promote dissolution of conductive foreign matters that have been mixed into the positive electrode will be shown.

充放電でリチウムイオンを吸蔵・放出する正極材料として、ＬｉＣｏＯ2を用いた。このＬｉＣｏＯ2を非特許文献１にしたがってＬｉ0．46ＣｏＯ2を調製した。また、導電性異物として、粒径がおよそ１５μｍの銅粉末を用意した。 LiCoO 2 was used as a positive electrode material that occludes and releases lithium ions by charging and discharging. This LiCoO 2 is made Li 0 . 46 CoO 2 was prepared. Moreover, the copper powder with a particle size of about 15 micrometers was prepared as an electroconductive foreign material.

正極板を以下のようにして作製した。まず、８３．５ｇのＬｉＣｏＯ2粉末と、１．５ｇのＬｉ0.46ＣｏＯ2と、０．０５５ｇの銅粉末と、１０ｇの導電剤であるアセチレンブラックと、５ｇの結着剤であるポリフッ化ビニリデン樹脂とを混合し、これらを脱水Ｎ−メチル−２−ピロリドンに分散させてスラリー状の正極合剤を調製した。この正極合剤をアルミニウム箔からなる正極集電体上に塗布し、乾燥後、圧延して、活物質層を形成した。そして、活物質層を形成したアルミニウム箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍのアルミニウム集電板に超音波溶接した。 A positive electrode plate was produced as follows. First, 83.5 g of LiCoO 2 powder, 1.5 g of Li 0.46 CoO 2 , 0.055 g of copper powder, 10 g of acetylene black as a conductive agent, and 5 g of polyvinylidene fluoride resin as a binder And these were dispersed in dehydrated N-methyl-2-pyrrolidone to prepare a slurry-like positive electrode mixture. This positive electrode mixture was applied onto a positive electrode current collector made of an aluminum foil, dried and then rolled to form an active material layer. The aluminum foil current collector on which the active material layer was formed was cut into a size of 35 mm × 35 mm and ultrasonically welded to a 0.5 mm thick aluminum current collector plate with a lead.

次に、人造黒鉛粉末を用いて、負極板を以下のようにして作製した。まず、７５ｇの人造黒鉛粉末と、２０ｇの導電剤としてのアセチレンブラックと、５ｇの結着剤としてのポリフッ化ビニリデン樹脂と、分散溶剤としての脱水Ｎ−メチル−２−ピロリドンを混合し、スラリー状の負極合剤を調製した。次に、この負極合剤を銅箔集電体の片面に、塗布、乾燥、圧延して活物質層を形成した。そして、活物質層を形成した銅箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍの銅集電板に超音波溶接し
た。 Next, a negative electrode plate was produced as follows using artificial graphite powder. First, 75 g of artificial graphite powder, 20 g of acetylene black as a conductive agent, 5 g of polyvinylidene fluoride resin as a binder, and dehydrated N-methyl-2-pyrrolidone as a dispersion solvent are mixed to form a slurry. A negative electrode mixture was prepared. Next, this negative electrode mixture was applied, dried and rolled on one side of a copper foil current collector to form an active material layer. And the copper foil collector which formed the active material layer was cut out to 35 mm x 35 mm size, and was ultrasonically welded to the 0.5 mm-thick copper collector plate with the lead | read | reed.

また、正極および負極の電位を測定するため、ニッケルリボンの先端にリチウム箔を圧着して、参照極を作製した。   Moreover, in order to measure the electric potential of a positive electrode and a negative electrode, the lithium foil was crimped | bonded to the front-end | tip of a nickel ribbon, and the reference electrode was produced.

非水電解液には、ＬｉＰＦ6とＥＣとＥＭＣを、ＬｉＰＦ6／ＥＣ／ＥＭＣ＝１／２．８／５．５（モル比）の組成となるように混合したものを用いた。 As the non-aqueous electrolyte, a mixture of LiPF 6 , EC and EMC so as to have a composition of LiPF 6 /EC/EMC=1/2.8/5.5 (molar ratio) was used.

電池の組み立ては以下のようにした。まず、厚みが１６μｍであるポリエチレン製の多孔質フィルムを間にして正極板および負極板を対向させ、正極板および負極板をテープ固定して一体化した。次に、この一体化物を両端が空いている筒状のアルミラミネート袋に納め、両極のリード部分において、袋の一方の開口部を溶着した。そして、他方の開口部から参照極を挿入するとともに、調製しておいた非水電解液を滴下した。   The battery was assembled as follows. First, a positive electrode plate and a negative electrode plate were opposed to each other with a polyethylene porous film having a thickness of 16 μm interposed therebetween, and the positive electrode plate and the negative electrode plate were fixed by tape and integrated. Next, this integrated product was placed in a cylindrical aluminum laminated bag having both ends open, and one opening portion of the bag was welded at the lead portions of both electrodes. And while inserting the reference electrode from the other opening part, the prepared non-aqueous electrolyte was dripped.

このようにして組み立てた実施例１の非水電解液二次電池を、−７５０ｍｍＨｇで５秒間、脱気した後、注液した開口部を溶着により封止した。そして、この電池を、４５℃で１週間放置した。   The non-aqueous electrolyte secondary battery of Example 1 assembled in this manner was degassed at −750 mmHg for 5 seconds, and then the injected opening was sealed by welding. The battery was left at 45 ° C. for 1 week.

（比較例１）
Ｌｉ0.46ＣｏＯ2を正極に混合していないほかは、実施例１と同様にして、非水電解液二次電池を組み立て、４５℃で１週間放置した。 (Comparative Example 1)
A nonaqueous electrolyte secondary battery was assembled in the same manner as in Example 1 except that Li 0.46 CoO 2 was not mixed with the positive electrode, and left at 45 ° C. for 1 week.

（電池の評価）
４５℃で放置後の正極および負極の電位を測定したところ、実施例１の電池では、正極の電位は３．９Ｖであり、負極の電位は３．１Ｖであった。一方、比較例１の電池では、正極の電位は３．２Ｖであり、負極の電位は３．１Ｖであった。 (Battery evaluation)
When the potential of the positive electrode and the negative electrode after being left at 45 ° C. was measured, in the battery of Example 1, the potential of the positive electrode was 3.9 V and the potential of the negative electrode was 3.1 V. On the other hand, in the battery of Comparative Example 1, the potential of the positive electrode was 3.2V, and the potential of the negative electrode was 3.1V.

実施例１および比較例１の電池を用いて、２０℃、１．５ｍＡ／ｃｍ2の条件で４．２Ｖ まで充電を行い、開回路電圧の推移を計測した。図１において、実線１は実施例１の電池について開回路電圧の推移をプロットしたものであり、破線２は比較例１の電池について開回路電圧の推移をプロットしたものである。比較例１の電池において、およそ４時間経過後から、急に開回路電圧が下がり始めている。この原因は次のように推察される。すなわち、比較例１の電池では、充電状態のＬｉ0．46ＣｏＯ2を含んでいないため、正極に混合した銅粉末が４５℃の放置期間中に溶解せず、充電電圧が４．２Ｖの充電によって初めて溶解する。このとき、負極の電位はおよそ８０ｍＶ ｖｓ． Ｌｉ／Ｌｉ+にまで低下しているので、溶解した銅イオンは電池内にひろく拡散せず、銅粉末が正極に存在していた場所と対向する負極上に局所析出する。この局所析出が成長し、内部短絡に至ったと考えられる。一方、実施例１の電池では、４５℃の放置期間中に銅粉末が正極より溶解し、電池内にひろく拡散してしまっているので、４．２Ｖまで充電をおこなっても内部短絡を抑制することができる。 Using the batteries of Example 1 and Comparative Example 1, the battery was charged to 4.2 V under the conditions of 20 ° C. and 1.5 mA / cm 2 , and the transition of the open circuit voltage was measured. In FIG. 1, the solid line 1 plots the transition of the open circuit voltage for the battery of Example 1, and the broken line 2 plots the transition of the open circuit voltage for the battery of Comparative Example 1. In the battery of Comparative Example 1, the open circuit voltage starts to drop suddenly after about 4 hours. The cause is presumed as follows. That is, in the battery of Comparative Example 1, Li 0 . Since it does not contain 46 CoO 2 , the copper powder mixed with the positive electrode does not dissolve during the standing period of 45 ° C., and dissolves only when the charging voltage is 4.2 V. At this time, the potential of the negative electrode is about 80 mV vs. approx. Since it has fallen to Li / Li + , the dissolved copper ions do not diffuse widely in the battery, but are locally deposited on the negative electrode facing the place where the copper powder was present in the positive electrode. It is thought that this local precipitation grew and led to an internal short circuit. On the other hand, in the battery of Example 1, since the copper powder was dissolved from the positive electrode during the 45 ° C. standing period and diffused extensively in the battery, internal short-circuiting was suppressed even when charging up to 4.2V. be able to.

なお、４．２Ｖ充電後の放置で開回路電圧が急に変化した電池の数は、組み立てた電池１００個ずつのうち、実施例１では０個、比較例１では１６個であった。   The number of batteries whose open circuit voltage changed suddenly after being charged after 4.2 V charging was 0 in Example 1 and 16 in Comparative Example 1 among 100 assembled batteries.

実施例１で使用したＬｉＣｏＯ2のかわりにＬｉＭｎ2Ｏ4を、Ｌｉ0.46ＣｏＯ2のかわりにλ−ＭｎＯ2を使用し、表１中のＡ〜Ｅに示した比率で混合した。そのほかは実施例１と同様にして、非水電解液二次電池を組み立てた。
LiMn 2 O 4 was used instead of LiCoO 2 used in Example 1, and λ-MnO 2 was used instead of Li 0.46 CoO 2 , and they were mixed at the ratios shown in A to E in Table 1. Other than that was carried out similarly to Example 1, and assembled the nonaqueous electrolyte secondary battery.

このようにして組み立てた実施例２の非水電解液電池を、４５℃で１週間放置した。そして、電池を４．２Ｖまで充電し、各組成の電池１００個ずつについて開回路電圧の変化を測定した。表２には、開回路電圧が急激に低下する電池の数をまとめた。また、正常な電池を５０個ずつ選び出し、２０℃、１．５ｍＡ／ｃｍ2の条件で、４．２Ｖと３．０Ｖの間で充放電を行い、電池の放電容量を求めた。表２に、各組成の電池での平均放電容量（正極活物質の重量で換算した値）を記載した。
The nonaqueous electrolyte battery of Example 2 assembled in this way was left at 45 ° C. for 1 week. And the battery was charged to 4.2V and the change of the open circuit voltage was measured about 100 batteries of each composition. Table 2 summarizes the number of batteries whose open circuit voltage drops rapidly. In addition, 50 normal batteries were selected and charged / discharged between 4.2 V and 3.0 V under the conditions of 20 ° C. and 1.5 mA / cm 2 to obtain the discharge capacity of the battery. Table 2 shows the average discharge capacity (value converted by the weight of the positive electrode active material) in the batteries having the respective compositions.

表２より、正極に充電状態の活物質を混合しておくことで、内部短絡の少ない電池が得られることがわかる。しかし、Ｅの組成では放電容量が大きく低下しており、これは、４５℃放置中に電解液との副反応が進行したためと推察される。表１と表２より、未充電状態の活物質に対する充電状態の活物質の比率は、３％以下が好ましいことがわかる。   Table 2 shows that a battery with few internal short circuits can be obtained by mixing an active material in a charged state with the positive electrode. However, in the composition of E, the discharge capacity is greatly reduced, which is presumably because a side reaction with the electrolyte progressed during standing at 45 ° C. From Table 1 and Table 2, it can be seen that the ratio of the active material in the charged state to the active material in the uncharged state is preferably 3% or less.

高電位で負極上において還元される添加剤を電解液に混合して、正極に紛れ込んだ導電性異物の溶解を促進する例を示す。   An example will be shown in which an additive that is reduced on the negative electrode at a high potential is mixed with an electrolytic solution to promote the dissolution of conductive foreign matter that has entered the positive electrode.

充放電でリチウムイオンを吸蔵・放出する正極材料として、ＬｉＣｏＯ2を用いた。また、導電性異物として、粒径がおよそ１０μｍの鉄粉末を用意した。 LiCoO 2 was used as a positive electrode material that occludes and releases lithium ions by charging and discharging. Moreover, iron powder having a particle size of approximately 10 μm was prepared as the conductive foreign matter.

正極板を以下のようにして作製した。まず、８５ｇのＬｉＣｏＯ2粉末と、０．０１６ｇ の鉄粉末と、１０ｇの導電剤であるアセチレンブラックと、５ｇの結着剤であるポリフッ化ビニリデン樹脂とを混合し、これらを脱水Ｎ−メチル−２−ピロリドンに分散させてスラリー状の正極合剤を調製した。この正極合剤をアルミニウム箔からなる正極集電体上に塗布し、乾燥後、圧延して、活物質層を形成した。そして、活物質層を形成したアル
ミニウム箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍのアルミニウム集電板に超音波溶接した。 A positive electrode plate was produced as follows. First, 85 g of LiCoO 2 powder, 0.016 g of iron powder, 10 g of acetylene black as a conductive agent, and 5 g of polyvinylidene fluoride resin as a binder were mixed, and these were mixed with dehydrated N-methyl- A slurry-like positive electrode mixture was prepared by dispersing in 2-pyrrolidone. This positive electrode mixture was applied onto a positive electrode current collector made of an aluminum foil, dried and then rolled to form an active material layer. The aluminum foil current collector on which the active material layer was formed was cut into a size of 35 mm × 35 mm and ultrasonically welded to a 0.5 mm thick aluminum current collector plate with a lead.

次に、人造黒鉛粉末を用いて、負極板を以下のようにして作製した。まず、７５ｇの人造黒鉛粉末と、２０ｇの導電剤としてのアセチレンブラックと、５ｇの結着剤としてのポリフッ化ビニリデン樹脂と、分散溶剤としての脱水Ｎ−メチル−２−ピロリドンを混合し、スラリー状の負極合剤を調製した。次に、この負極合剤を銅箔集電体の片面に、塗布、乾燥、圧延して活物質層を形成した。そして、活物質層を形成した銅箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍの銅集電板に超音波溶接した。   Next, a negative electrode plate was produced as follows using artificial graphite powder. First, 75 g of artificial graphite powder, 20 g of acetylene black as a conductive agent, 5 g of polyvinylidene fluoride resin as a binder, and dehydrated N-methyl-2-pyrrolidone as a dispersion solvent are mixed to form a slurry. A negative electrode mixture was prepared. Next, this negative electrode mixture was applied, dried and rolled on one side of a copper foil current collector to form an active material layer. And the copper foil collector which formed the active material layer was cut out to 35 mm x 35 mm size, and was ultrasonically welded to the 0.5 mm-thick copper collector plate with the lead | read | reed.

また、正極および負極の電位を測定するため、ニッケルリボンの先端にリチウム箔を圧着して、参照極を作製した。   Moreover, in order to measure the electric potential of a positive electrode and a negative electrode, the lithium foil was crimped | bonded to the front-end | tip of a nickel ribbon, and the reference electrode was produced.

負極上での還元電位が１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+であるような添加剤として、無水フタロン酸を用いた。ＬｉＰＦ6とＥＣとＥＭＣを、ＬｉＰＦ6／ＥＣ／ＥＭＣ＝１／２．８／５．５（モル比）の組成となるように混合した非水電解液１００ｇに、さらに、無水フタロン酸を２５０ｍｇ 混合した。 The reduction potential on the negative electrode is 1.5 V vs. As an additive such as Li / Li + , phthalonic anhydride was used. LiPF 6 , EC and EMC were mixed with 100 g of a non-aqueous electrolyte in which a composition of LiPF 6 /EC/EMC=1/2.8/5.5 (molar ratio) was mixed, and 250 mg of phthalonic anhydride was further added. Mixed.

電池の組み立ては以下のようにした。まず、厚みが１６μｍであるポリエチレン製の多孔質フィルムを間にして正極板および負極板を対向させ、正極板および負極板をテープ固定して一体化した。次に、この一体化物を両端が空いている筒状のアルミラミネート袋に納め、両極のリード部分において、袋の一方の開口部を溶着した。そして、他方の開口部から参照極を挿入するとともに、調製しておいた非水電解液を滴下した。   The battery was assembled as follows. First, a positive electrode plate and a negative electrode plate were opposed to each other with a polyethylene porous film having a thickness of 16 μm interposed therebetween, and the positive electrode plate and the negative electrode plate were fixed by tape and integrated. Next, this integrated product was placed in a cylindrical aluminum laminated bag having both ends open, and one opening portion of the bag was welded at the lead portions of both electrodes. And while inserting the reference electrode from the other opening part, the prepared non-aqueous electrolyte was dripped.

なお、組み立てた電池における、正極活物質のＬｉＣｏＯ2の量はおよそ２５０ｍｇであり、無水フタロン酸の量はおよそ０．５ｍｇである。 In the assembled battery, the amount of the positive electrode active material LiCoO 2 is about 250 mg, and the amount of phthalonic anhydride is about 0.5 mg.

このようにして組み立てた実施例３の非水電解液二次電池を、−７５０ｍｍＨｇで５秒間、脱気した後、注液した開口部を溶着により封止した。そして、この電池を、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った後、４５℃で１週間、放置した。 The non-aqueous electrolyte secondary battery of Example 3 assembled in this manner was degassed at −750 mmHg for 5 seconds, and then the poured opening was sealed by welding. The battery was charged for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , and then left at 45 ° C. for 1 week.

（比較例２）
非水電解液に無水フタロン酸を混合していないほかは、実施例３と同様にして、非水電解液二次電池を組み立てた。そして、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った後、４５℃で１週間、放置した。 (Comparative Example 2)
A nonaqueous electrolyte secondary battery was assembled in the same manner as in Example 3 except that phthalonic anhydride was not mixed with the nonaqueous electrolyte. Then, after charging for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , it was left at 45 ° C. for 1 week.

（電池の評価）
実施例３の電池の正極および負極の電位を測定したところ、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った直後では、正極の電位は３．９Ｖであり、負極の電位は２．４Ｖであったが、４５℃放置後では、負極の電位は３．０Ｖに上昇していた。一方、比較例２の電池における正極の電位は、実施例３の電池と同様であったが、負極の電位は４５℃放置後でも１Ｖと低いままであった。 (Battery evaluation)
When the potentials of the positive electrode and the negative electrode of the battery of Example 3 were measured, immediately after charging for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , the potential of the positive electrode was 3.9 V. Although the potential was 2.4 V, the potential of the negative electrode rose to 3.0 V after being left at 45 ° C. On the other hand, the potential of the positive electrode in the battery of Comparative Example 2 was the same as that of the battery of Example 3, but the potential of the negative electrode remained as low as 1 V even after being left at 45 ° C.

実施例３および比較例２の電池を１００個ずつ、２０℃、１．５ｍＡ／ｃｍ2の条件で、４．２Ｖ まで充電し、それぞれの電池について開回路電圧の変化を測定した。その結果、実施例３の電池で開回路電圧が急激に低下したものはなく、比較例２の電池では、１１個であった。この原因は次のように推察される。すなわち、実施例３および比較例２の電池では、正極に混合した鉄粉末が４５℃の放置期間中に溶解する。ここで、実施例３の
電池では、無水フタロン酸を電解液に含んでいるので、負極の電位が低下せず、正極で生成した鉄イオンが局所析出することがない。一方、比較例２の電池では、負極の電位はおよそ１Ｖ ｖｓ． Ｌｉ／Ｌｉ+にまで低下しているので、溶解した鉄イオンは電池内にひろく拡散することができず、鉄粉末が正極に存在していた場所と対向する負極上に局所析出する。この局所析出が成長し、内部短絡に至ったと考えられる。 100 batteries of Example 3 and Comparative Example 2 were charged to 4.2 V under the conditions of 20 ° C. and 1.5 mA / cm 2 , and the change in open circuit voltage was measured for each battery. As a result, none of the batteries of Example 3 had a sudden drop in open circuit voltage, and the number of batteries of Comparative Example 2 was 11. The cause is presumed as follows. That is, in the batteries of Example 3 and Comparative Example 2, the iron powder mixed with the positive electrode dissolves during the standing period of 45 ° C. Here, in the battery of Example 3, since phthalonic anhydride is contained in the electrolytic solution, the potential of the negative electrode does not decrease, and iron ions generated at the positive electrode are not locally deposited. On the other hand, in the battery of Comparative Example 2, the negative electrode potential was about 1 V vs. Since it is lowered to Li / Li + , the dissolved iron ions cannot diffuse widely in the battery, and the iron powder is locally deposited on the negative electrode facing the place where the positive electrode was present. It is thought that this local precipitation grew and led to an internal short circuit.

非水電解液に混合する添加剤として、ジフェニルジスルホン（Ｃ6Ｈ5−ＳＯ2−ＳＯ2−Ｃ6Ｈ5、以下、ＤＰＤＳと略記）を用い、表３に示すような比率で電解液に混合したほかは、実施例３と同様にして電池を組み立てた。そして、この電池を、２０℃、０．０１５ｍＡ／ｃｍ2 の条件で、３０分間充電を行った後、４５℃で１週間、放置した。
Diphenyldisulfone (C 6 H 5 —SO 2 —SO 2 —C 6 H 5 , hereinafter abbreviated as DPDS) was used as an additive to be mixed with the non-aqueous electrolyte, and the ratio of the electrolyte shown in Table 3 was used. A battery was assembled in the same manner as in Example 3 except for mixing. The battery was charged for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , and then left at 45 ° C. for 1 week.

このようにして組み立てた実施例４の非水電解液電池を、２０℃、１．５ｍＡ／ｃｍ2 の条件で、４．２Ｖまで充電し、それぞれの電池について開回路電圧の変化を測定した。各組成の電池１００個ずつについて開回路電圧の変化を測定した。表４には、開回路電圧が急激に低下する電池の数をまとめた。また、正常な電池を５０個ずつ選び出し、２０℃、１．５ｍＡ／ｃｍ2 の条件で、４．２Ｖと３．０Ｖの間で充放電を行い、電池の放電容量を求めた。表４に、各組成の電池での平均放電容量（正極活物質の重量で換算した値）を記載した。
The nonaqueous electrolyte battery of Example 4 assembled in this manner was charged to 4.2 V under the conditions of 20 ° C. and 1.5 mA / cm 2 , and the change in open circuit voltage was measured for each battery. The change in open circuit voltage was measured for 100 batteries of each composition. Table 4 summarizes the number of batteries whose open circuit voltage drops rapidly. In addition, 50 normal batteries were selected and charged / discharged between 4.2 V and 3.0 V under the conditions of 20 ° C. and 1.5 mA / cm 2 to obtain the discharge capacity of the battery. Table 4 shows the average discharge capacity (value converted by the weight of the positive electrode active material) in the battery of each composition.

表４より、高電位で還元される添加剤を電解液中に混合しておくことで、内部短絡の少ない電池が得られることがわかる。しかし、Ｊの組成では放電容量が大きく低下しており、これは、添加剤の還元物が負極上に著しく堆積するために負極の負荷特性が劣化したか
らと考えられる。表３と表４より、電解液中の添加剤の量はおおむね０．５％以下が好ましいことがわかる。 Table 4 shows that a battery with few internal short circuits can be obtained by mixing an additive that is reduced at a high potential in the electrolyte. However, in the composition of J, the discharge capacity is greatly reduced. This is presumably because the load characteristics of the negative electrode deteriorated because the reduced product of the additive was remarkably deposited on the negative electrode. From Tables 3 and 4, it can be seen that the amount of the additive in the electrolytic solution is preferably about 0.5% or less.

高電位で還元される化合物を負極に混合して、正極に紛れ込んだ導電性異物の溶解を促進する例を示す。   An example will be shown in which a compound that is reduced at a high potential is mixed with a negative electrode to promote dissolution of conductive foreign matters mixed in the positive electrode.

充放電でリチウムイオンを吸蔵・放出する正極材料として、ＬｉＣｏＯ2を用いた。また、導電性異物として、粒径がおよそ１５μｍの銅粉末を用意した。また、１．５Ｖ ｖｓ． Ｌｉ／Ｌｉ+ 以上の電位において負極内で還元される化合物として、４５０℃で加熱処理したＭｎＯ2を用いた。 LiCoO 2 was used as a positive electrode material that occludes and releases lithium ions by charging and discharging. Moreover, the copper powder with a particle size of about 15 micrometers was prepared as an electroconductive foreign material. In addition, 1.5V vs. MnO 2 heat-treated at 450 ° C. was used as a compound that is reduced in the negative electrode at a potential of Li / Li + or higher.

正極板を以下のようにして作製した。まず、８５ｇのＬｉＣｏＯ2粉末と、０．０５５ｇ の銅粉末と、１０ｇの導電剤であるアセチレンブラックと、５ｇの結着剤であるポリフッ化ビニリデン樹脂とを混合し、これらを脱水Ｎ−メチル−２−ピロリドンに分散させてスラリー状の正極合剤を調製した。この正極合剤をアルミニウム箔からなる正極集電体上に塗布し、乾燥後、圧延して、活物質層を形成した。そして、活物質層を形成したアルミニウム箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍのアルミニウム集電板に超音波溶接した。 A positive electrode plate was produced as follows. First, 85 g of LiCoO 2 powder, 0.055 g of copper powder, 10 g of acetylene black as a conductive agent, and 5 g of polyvinylidene fluoride resin as a binder were mixed, and these were mixed with dehydrated N-methyl- A slurry-like positive electrode mixture was prepared by dispersing in 2-pyrrolidone. This positive electrode mixture was applied onto a positive electrode current collector made of an aluminum foil, dried and then rolled to form an active material layer. The aluminum foil current collector on which the active material layer was formed was cut into a size of 35 mm × 35 mm and ultrasonically welded to a 0.5 mm thick aluminum current collector plate with a lead.

次に、人造黒鉛粉末を用いて、負極板を以下のようにして作製した。まず、７５ｇの人造黒鉛粉末と、２０ｇの導電剤としてのアセチレンブラックと、５ｇの結着剤としてのポリフッ化ビニリデン樹脂と、０．２８ｇのＭｎＯ2と、分散溶剤としての脱水Ｎ−メチル−２−ピロリドンを混合し、スラリー状の負極合剤を調製した。次に、この負極合剤を銅箔集電体の片面に、塗布、乾燥、圧延して活物質層を形成した。そして、活物質層を形成した銅箔集電体を３５ｍｍ×３５ｍｍサイズに切り出し、リードのついた厚み０．５ｍｍの銅集電板に超音波溶接した。 Next, a negative electrode plate was produced as follows using artificial graphite powder. First, 75 g of artificial graphite powder, 20 g of acetylene black as a conductive agent, 5 g of polyvinylidene fluoride resin as a binder, 0.28 g of MnO 2, and dehydrated N-methyl-2 as a dispersion solvent -Pyrrolidone was mixed to prepare a slurry-like negative electrode mixture. Next, this negative electrode mixture was applied, dried and rolled on one side of a copper foil current collector to form an active material layer. And the copper foil collector which formed the active material layer was cut out to 35 mm x 35 mm size, and was ultrasonically welded to the 0.5 mm-thick copper collector plate with the lead | read | reed.

また、正極および負極の電位を測定するため、ニッケルリボンの先端にリチウム箔を圧着して、参照極を作製した。   Moreover, in order to measure the electric potential of a positive electrode and a negative electrode, the lithium foil was crimped | bonded to the front-end | tip of a nickel ribbon, and the reference electrode was produced.

非水電解液として、ＬｉＰＦ6とＥＣとＥＭＣを、ＬｉＰＦ6／ＥＣ／ＥＭＣ＝１／２．８／５．５（モル比）の組成となるように混合したものを用いた。 As the non-aqueous electrolyte, a mixture of LiPF 6 , EC and EMC so as to have a composition of LiPF 6 /EC/EMC=1/2.8/5.5 (molar ratio) was used.

電池の組み立ては以下のようにした。まず、厚みが１６μｍであるポリエチレン製の多孔質フィルムを間にして正極板および負極板を対向させ、正極板および負極板をテープ固定して一体化した。次に、この一体化物を両端が空いている筒状のアルミラミネート袋に納め、両極のリード部分において、袋の一方の開口部を溶着した。そして、他方の開口部から参照極を挿入するとともに、調製しておいた非水電解液を滴下した。   The battery was assembled as follows. First, a positive electrode plate and a negative electrode plate were opposed to each other with a polyethylene porous film having a thickness of 16 μm interposed therebetween, and the positive electrode plate and the negative electrode plate were fixed by tape and integrated. Next, this integrated product was placed in a cylindrical aluminum laminated bag having both ends open, and one opening portion of the bag was welded at the lead portions of both electrodes. And while inserting the reference electrode from the other opening part, the prepared non-aqueous electrolyte was dripped.

なお、組み立てた電池における、正極活物質のＬｉＣｏＯ2の量はおよそ２５０ｍｇであり、負極中のＭｎＯ2の量はおよそ０．４４ｍｇである。 In the assembled battery, the amount of LiCoO 2 of the positive electrode active material is about 250 mg, and the amount of MnO 2 in the negative electrode is about 0.44 mg.

このようにして組み立てた実施例５の非水電解液二次電池を、−７５０ｍｍＨｇで５秒間、脱気した後、注液した開口部を溶着により封止した。そして、この電池を、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った後、４５℃で１週間、放置した。 The nonaqueous electrolyte secondary battery of Example 5 assembled in this manner was degassed at −750 mmHg for 5 seconds, and then the injected opening was sealed by welding. The battery was charged for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , and then left at 45 ° C. for 1 week.

（比較例３）
負極にＭｎＯ2を混合していないほかは、実施例５と同様にして、非水電解液二次電池
を組み立てた。そして、２０℃、０．０１５ｍＡ／ｃｍ2 の条件で、３０分間充電を行った後、４５℃で１週間、放置した。 (Comparative Example 3)
A nonaqueous electrolyte secondary battery was assembled in the same manner as in Example 5 except that MnO 2 was not mixed in the negative electrode. Then, after charging for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , it was left at 45 ° C. for 1 week.

（電池の評価）
実施例５の電池の正極および負極の電位を測定したところ、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った直後では、正極の電位は３．９Ｖであり、負極の電位は３．１Ｖであり、４５℃放置後でも、負極の電位は３．２Ｖと高かった。一方、比較例３の電池における正極の電位は、実施例５の電池と同様であったが、負極の電位は４５℃放置後でも１Ｖと低いままであった。 (Battery evaluation)
When the potentials of the positive electrode and negative electrode of the battery of Example 5 were measured, immediately after charging for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , the potential of the positive electrode was 3.9 V. The potential was 3.1 V, and the potential of the negative electrode was as high as 3.2 V even after being left at 45 ° C. On the other hand, the potential of the positive electrode in the battery of Comparative Example 3 was the same as that of the battery of Example 5, but the potential of the negative electrode remained as low as 1 V even after being left at 45 ° C.

実施例５および比較例３の電池を１００個ずつ、２０℃、１．５ｍＡ／ｃｍ2の条件で、４．２Ｖまで充電し、それぞれの電池について開回路電圧の変化を測定した。その結果、実施例５の電池で開回路電圧が急激に低下したものはなく、比較例３の電池では、１６個であった。この原因は次のように推察される。すなわち、実施例５および比較例３の電池では、正極に混合した銅粉末が４５℃の放置期間中に溶解する。ここで、実施例５の電池では、ＭｎＯ2を負極に混合しているので、負極の電位が低下せず、正極で生成した銅イオンが局所析出することがない。一方、比較例３の電池では、負極の電位はおよそ１Ｖ
ｖｓ． Ｌｉ／Ｌｉ+にまで低下しているので、溶解した銅イオンは電池内にひろく拡散することができず、銅粉末が正極に存在していた場所と対向する負極上に局所析出する。この局所析出が成長し、内部短絡に至ったと考えられる。 100 batteries of Example 5 and Comparative Example 3 were charged to 4.2 V under the conditions of 20 ° C. and 1.5 mA / cm 2 , and the change in open circuit voltage was measured for each battery. As a result, none of the batteries of Example 5 had a sudden drop in open circuit voltage, and the number of batteries of Comparative Example 3 was 16. The cause is presumed as follows. That is, in the batteries of Example 5 and Comparative Example 3, the copper powder mixed in the positive electrode is dissolved during the standing period of 45 ° C. Here, in the battery of Example 5, since MnO 2 was mixed with the negative electrode, the potential of the negative electrode was not lowered, and the copper ions generated at the positive electrode were not locally deposited. On the other hand, in the battery of Comparative Example 3, the potential of the negative electrode is about 1V.
vs. Since it is lowered to Li / Li + , the dissolved copper ions cannot be diffused widely in the battery, and the copper powder is locally deposited on the negative electrode facing the place where the positive electrode was present. It is thought that this local precipitation grew and led to an internal short circuit.

負極中に混合する化合物として、導電性高分子であるポリピロール（組成は、Ｃ4ＮＨ2・０．１ＰＦ6）を用い、表５に示すような比率で負極に混合したほかは、実施例５と同様にして電池を組み立てた。そして、この電池を、２０℃、０．０１５ｍＡ／ｃｍ2の条件で、３０分間充電を行った後、４５℃で１週間、放置した。
Example 5 except that polypyrrole (composition is C 4 NH 2 .0.1PF 6 ), which is a conductive polymer, was used as a compound to be mixed in the negative electrode, and was mixed in the negative electrode at the ratio shown in Table 5. A battery was assembled in the same manner as described above. The battery was charged for 30 minutes under the conditions of 20 ° C. and 0.015 mA / cm 2 , and then left at 45 ° C. for 1 week.

このようにして組み立てた実施例６の非水電解液電池を、２０℃、１．５ｍＡ／ｃｍ2 の条件で、４．２Ｖ まで充電し、それぞれの電池について開回路電圧の変化を測定した。各組成の電池１００個ずつについて開回路電圧の変化を測定した。表６には、開回路電圧が急激に低下する電池の数をまとめた。また、正常な電池を５０個ずつ選び出し、２０℃、１．５ｍＡ／ｃｍ2の条件で、４．２Ｖ と３．０Ｖの間で充放電を行い、電池の放電容量を求めた。表６に、各組成の電池での平均放電容量（正極活物質の重量で換算した値）を記載した。
The nonaqueous electrolyte battery of Example 6 thus assembled was charged to 4.2 V under the conditions of 20 ° C. and 1.5 mA / cm 2 , and the change in open circuit voltage was measured for each battery. The change in open circuit voltage was measured for 100 batteries of each composition. Table 6 summarizes the number of batteries whose open circuit voltage drops rapidly. Further, 50 normal batteries were selected and charged / discharged between 4.2 V and 3.0 V under the conditions of 20 ° C. and 1.5 mA / cm 2 to obtain the discharge capacity of the battery. Table 6 shows the average discharge capacity (value converted by the weight of the positive electrode active material) in the batteries having the respective compositions.

表６より、高電位で還元される化合物を負極中に混合しておくことで、内部短絡の少ない電池が得られることがわかる。しかし、Ｏの組成では放電容量が大きく低下しており、これは、化合物の還元物が絶縁体であるために負極の負荷特性が劣化したからと考えられる。表５と表６より、負極中の化合物の量はおおむね０．４％以下が好ましいことがわかる。   From Table 6, it can be seen that a battery with few internal short circuits can be obtained by mixing a compound reduced at a high potential in the negative electrode. However, the discharge capacity is greatly reduced in the composition of O. This is considered to be because the load characteristics of the negative electrode deteriorated because the reduced product of the compound was an insulator. From Table 5 and Table 6, it can be seen that the amount of the compound in the negative electrode is preferably about 0.4% or less.

以上のように本発明によれば、内部短絡が少なく、信頼性に優れた非水電解液二次電池を得ることができるため、ノートパソコン、携帯電話、ビデオカメラ、小型ゲーム機器などに非常に有用である。   As described above, according to the present invention, a non-aqueous electrolyte secondary battery with few internal short circuits and excellent reliability can be obtained, which is very useful for notebook computers, mobile phones, video cameras, small game devices, and the like. Useful.

非水電解液二次電池における開回路電圧の時間推移の関係を示す図The figure which shows the relationship of the time transition of the open circuit voltage in a nonaqueous electrolyte secondary battery

符号の説明Explanation of symbols

１ 実線
２ 破線
1 Solid line 2 Broken line

Claims (3)

リチウムイオンを吸蔵した活物質からなる正極と、リチウムイオンを吸蔵していない活物質からなる負極とを、セパレータをはさんで一体化して極板群を形成した後、非水電解液を注液し、初回の充電後に放置を行う非水電解液二次電池の製造法において、
前記正極には、さらに充電状態の活物質が混合されており、前記注液後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うことを特徴とする非水電解液二次電池の製造法。 A positive electrode made of an active material that occludes lithium ions and a negative electrode made of an active material that does not occlude lithium ions are integrated with a separator interposed therebetween to form an electrode plate group, and then a non-aqueous electrolyte is injected. In the method of manufacturing a non-aqueous electrolyte secondary battery that is left after the first charge,
The positive electrode is further mixed with an active material in a charged state, and after pouring, the negative electrode is left in a state in which lithium ions are not occluded. Battery manufacturing method. リチウムイオンを吸蔵した活物質からなる正極と、リチウムイオンを吸蔵していない活物質からなる負極とを、セパレータをはさんで一体化して極板群を形成した後、非水電解液を注液し、初回の充電後に放置を行う非水電解液二次電池の製造法において、
前記非水電解液には、さらに１．５Ｖ ｖｓ．Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤が混合されており、初回の充電は、前記負極にリチウムイオンを吸蔵しない状態で正極電位を変化させる充電であり、その後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うことを特徴とする非水電解液二次電池の製造法。 A positive electrode made of an active material that occludes lithium ions and a negative electrode made of an active material that does not occlude lithium ions are integrated with a separator interposed therebetween to form an electrode plate group, and then a non-aqueous electrolyte is injected. In the method of manufacturing a non-aqueous electrolyte secondary battery that is left after the first charge,
The non-aqueous electrolyte further includes 1.5 V vs. Additives that are reduced on the negative electrode at a potential of Li / Li + or higher are mixed, and the initial charge is a charge that changes the positive electrode potential without occluding lithium ions in the negative electrode, and then the negative electrode A method for producing a non-aqueous electrolyte secondary battery, wherein the battery is left in a state where lithium ions are not occluded. リチウムイオンを吸蔵した活物質からなる正極と、リチウムイオンを吸蔵していない活物質からなる負極とを、セパレータをはさんで一体化して極板群を形成した後、非水電解液を注液し、初回の充電後に放置を行う非水電解液二次電池の製造法において、
前記負極には、さらに１．５Ｖ ｖｓ．Ｌｉ／Ｌｉ+以上の電位において負極上で還元される添加剤が混合されており、初回の充電は、前記負極にリチウムイオンを吸蔵しない状態で正極電位を変化させる充電であり、その後、前記負極にリチウムイオンを吸蔵していない状態のままで放置を行うことを特徴とする非水電解液二次電池の製造法。

A positive electrode made of an active material that occludes lithium ions and a negative electrode made of an active material that does not occlude lithium ions are integrated with a separator interposed therebetween to form an electrode plate group, and then a non-aqueous electrolyte is injected. In the method of manufacturing a non-aqueous electrolyte secondary battery that is left after the first charge,
The negative electrode further includes 1.5 V vs. Additives that are reduced on the negative electrode at a potential of Li / Li + or higher are mixed, and the initial charge is a charge that changes the positive electrode potential without occluding lithium ions in the negative electrode, and then the negative electrode A method for producing a non-aqueous electrolyte secondary battery, wherein the battery is left in a state where lithium ions are not occluded.

JP2005204158A 2005-07-13 2005-07-13 Manufacturing method of non-aqueous electrolyte secondary battery Expired - Fee Related JP4899361B2 (en)

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WO2011111153A1 (en) * 2010-03-08 2011-09-15 トヨタ自動車株式会社 Device for treatment of non-aqueous electrolyte secondary battery, and process for production of non-aqueous electrolyte secondary battery
JP2011249058A (en) * 2010-05-25 2011-12-08 Toyota Central R&D Labs Inc Anode for lithium ion secondary battery, lithium ion secondary battery and method of manufacturing anode for lithium ion secondary battery
JP2012160377A (en) * 2011-02-01 2012-08-23 Hitachi Vehicle Energy Ltd Secondary battery and method of manufacturing the same
WO2013121563A1 (en) * 2012-02-16 2013-08-22 トヨタ自動車株式会社 Method for manufacturing secondary cell
JP2014120355A (en) * 2012-12-18 2014-06-30 Gs Yuasa Corp Method for manufacturing nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
WO2016002586A1 (en) * 2014-07-04 2016-01-07 Jsr株式会社 Binder composition for power storage devices
US9406967B2 (en) 2010-12-17 2016-08-02 Toyota Jidosha Kabushiki Kaisha Method for producing lithium secondary cell

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WO2011111153A1 (en) * 2010-03-08 2011-09-15 トヨタ自動車株式会社 Device for treatment of non-aqueous electrolyte secondary battery, and process for production of non-aqueous electrolyte secondary battery
US10707533B2 (en) 2010-03-08 2020-07-07 Toyota Jidosha Kabushiki Kaisha Processing device of nonaqueous electrolyte secondary battery and manufacturing method thereof
JP5348139B2 (en) * 2010-03-08 2013-11-20 トヨタ自動車株式会社 Non-aqueous electrolyte secondary battery processing apparatus and manufacturing method
JP2011249058A (en) * 2010-05-25 2011-12-08 Toyota Central R&D Labs Inc Anode for lithium ion secondary battery, lithium ion secondary battery and method of manufacturing anode for lithium ion secondary battery
US9406967B2 (en) 2010-12-17 2016-08-02 Toyota Jidosha Kabushiki Kaisha Method for producing lithium secondary cell
JP2012160377A (en) * 2011-02-01 2012-08-23 Hitachi Vehicle Energy Ltd Secondary battery and method of manufacturing the same
CN104115326A (en) * 2012-02-16 2014-10-22 丰田自动车株式会社 Method for manufacturing secondary cell
JPWO2013121563A1 (en) * 2012-02-16 2015-05-11 トヨタ自動車株式会社 Manufacturing method of secondary battery
WO2013121563A1 (en) * 2012-02-16 2013-08-22 トヨタ自動車株式会社 Method for manufacturing secondary cell
JP2014120355A (en) * 2012-12-18 2014-06-30 Gs Yuasa Corp Method for manufacturing nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
WO2016002586A1 (en) * 2014-07-04 2016-01-07 Jsr株式会社 Binder composition for power storage devices
JP5904350B1 (en) * 2014-07-04 2016-04-13 Jsr株式会社 Binder composition for electricity storage device
US10505195B2 (en) 2014-07-04 2019-12-10 Jsr Corporation Method for producing electrical storage device electrode with binder composition

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