JP2004356044A - Manufacturing method of ion conductor, and manufacturing method of secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an ion conductor which can be manufactured by a simple method at low cost having a high ion conductivity and an excellent mechanical strength by further enhancing aligning property of a polymer skeleton of the ion conductor, and to provide a manufacturing method of a secondary battery having excellent cycle life performance. <P>SOLUTION: The manufacturing method of the ion conductor mainly composed of at least one kind of polymer compound and electrolyte, having anisotropic characteristics in ion conductivity, has a polymerization step of forming the ion conductor by a polymerization reaction of a polymer precursor including at least one kind of a monomer and the electrolyte. In the polymerization step, during the polymerization reaction, the precursor of the polymer is kept at a temperature not higher than a temperature in which the monomer in the precursor shows the aligning property. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（式中、Ｒ１およびＲ２はそれぞれ水素原子あるいは炭素数２以下のアルキル基であり、Ａ及びＢはそれぞれ少なくともポリエーテルを含有する基であり、Ｒ３は少なくとも炭素数１〜４のアルキル基を有する基である。）
【００１７】
前記一般式（１）のＡもしくはＢのいずれか一方が―（ＣＨ_２―ＣＨ_２―Ｏ）_ｍ―であり、他方が―（ＣＨ_２―ＣＨ_２（ＣＨ_３）―Ｏ）_ｎ―（ｍ、ｎは１〜３０の整数）であることが好ましい。 前記ｍおよびｎが、ｍ／ｎ＝０．５〜２であることがより好ましい。
【００１８】
また、本発明における前記イオン伝導体は、下記一般式（２）で表されるセグメントを少なくとも含有する高分子鎖から構成されるものであることができる。
【化４】
一般式（２）

（式中、Ｒ４およびＲ５はそれぞれ水素原子あるいは炭素数２以下のアルキル基であり、Ｘは―（ＣＨ_２―ＣＨ_２―Ｏ）_ｋ―（ｋは１〜４０の整数）を含有する基であり、Ｒ６は少なくとも炭素数６〜２２の直鎖状のアルキル基または炭素数６〜２２の直鎖状のアルキル基を有するアルキルベンジル基である。）
【００１９】
【発明の実施の形態】
まず、本発明のイオン伝導体の製造方法について説明する。
本発明らは、主として少なくとも一種類の高分子化合物と少なくとも一種類の電解質で構成されるイオン伝導性に異方性を有するイオン伝導体を製造すべく、少なくとも一種類のモノマーと少なくとも一種類の電解質を含有するポリマー前駆体を、該前駆体中のモノマーが配向性を示す温度以下の温度に保温しながら重合反応に付した。その結果、配向性を有する主鎖部と側鎖部を備え且つ架橋構造を備えたポリマー鎖を有するポリマーからなるイオン伝導体を作製することができた。そしてこのイオン伝導体は、機械強度に優れたものであることが判った。また、このイオン伝導体を使用して作製したリチウム二次電池は、高容量で充放電効率が高く長寿命のものであった。本発明は、これらの発見事項に基づくものである。
【００２０】
上述した手法により優れた特性を有する前記イオン伝導体が作製できる理由は次のように考えられる。即ち、配向性を持つ側鎖を有するモノマーを含有する状態で重合を行うと、側鎖部が配向した状態を形成することで、主鎖部自体も配向性を持ち、ポリマー全体が配向構造を形成し、重合時の温度をモノマーが配向する温度以下に保温することにより、生成した重合体がより配向性の高い構造を有するようになると考えられる。生成したポリマーはモノマーに比べ分子運動が鈍るため、モノマーの配向する温度以上になってもこの配向構造は維持される。このようなポリマーが電解質を保持するとき、イオン拡散はポリマーの配向方向に規制される。電解質を保持するポリマー中のある２点間での電解質の移動速度を考えるとき、ポリマーが無秩序な状態であるよりも配向構造のため秩序だっており、その２点を結んだ直線の方向にポリマーが方向性を有しているならば、後者の方が移動距離が短くなり、一定空間内のイオン数およびイオンの移動度が同一であれば後者の移動速度が速くなると考えられる。このため分子の並ぶ方向に沿った方向ではそれ以外の方向に比べてイオン伝導性が向上するようになる。言い換えればイオン伝導性に異方性を生じるようになる。
【００２１】
図１は本発明のイオン伝導体の高分子構造を模式的に示す図である。図１（ａ）のように高分子化合物を構成する高分子鎖の側鎖部１０２と主鎖（部）１０１がそれぞれ配向することで、規則正しい高分子鎖の骨格構造が形成できる。また、本発明のイオン伝導体を構成する高分子鎖は架橋結合１０３を形成しているため、立体的に規則性を持つ強固な骨格構造を形成することができ、機械的強度に優れたイオン伝導体が得られると考えられる。この際、図１のようにポリエーテル基を含有する側鎖部が一定方向に配向することによって、ポリエーテル基と親和性のある電解質はポリエーテル基の配向方向に移動しやすくなる。つまり図１（ａ）のようなイオン伝導経路１０４が一定方向に形成される。配向性を持たず無秩序にポリエーテル基が存在する図１（ｂ）のようなものに比べてイオンの伝導経路方向にイオンが移動しやすくなり、イオン伝導性が向上すると考えられる。
【００２２】
上述したように、本発明のイオン伝導体の製造方法は、所定のモノマーと所定の電解質を混合して得られたポリマー前駆体を、前記モノマーが配向性を示す温度以下の温度に保温しながら重合すること特徴とする。以下に、本発明のイオン伝導体の製造方法の好ましい態様について図２及び図４を参照して詳細に説明する。
図２は、本発明のイオン伝導体の製造方法の一例のフローチャートを示したものであり、図４は本発明のイオン伝導体の製造方法で使用する製造装置の好ましい一例を示したものである。なお、図４において、３０１は重合容器、３０２は温度調節装置、３０３は光エネルギー照射装置、をそれぞれ示す。
【００２３】
図２に徴して本発明のイオン伝導体の製造方法を説明する。
上記一般式（１）に従うポリエーテル基を含有する側鎖を有する第１のモノマー、溶媒、及び電解質を混合する。必要に応じて側鎖にポリエーテル基、シアノ基、アミノ基、アミド基及びカーボネート基からなる群から選択される少なくとも一種類の極性基を有する第２のモノマー及び架橋構造を形成し得る第３のモノマーを添加する。重合開始剤をこの混合物に添加して均一混合系になるまでよく攪拌する（工程Ａ）。次いで、この混合物（３０４）を図４の重合容器３０１中に挿入し（工程Ｂ）、図４の温度調節装置３０２でモノマーが配向性を示す温度以下に保温しながら、紫外線等のエネルギーをこの容器内に照射して重合反応を行う（工程Ｃ）。重合容器３０１を常温に戻し該容器内から重合生成物を取り出しイオン伝導体を得る（工程Ｄ）。
上記重合反応時の保温温度としては、上記モノマーが配向性を示す温度より０〜１００℃低いことが望ましい。より好ましくは、上記モノマーが配向性をを示す温度より５〜７０℃低いことが望ましい。
【００２４】
上記各モノマーの添加量としては、まず第１のモノマーと第２のモノマーの混合比率が、第１のモノマーのモル数／第２のモノマーのモル数＝０．０１〜１、好ましくは０．０２〜０．５となる様に混合することが、高分子化合物と溶媒との親和性が良好になるため望ましい。また、第３のモノマーの添加量としては、（第１のモノマーのモル数＋第２のモノマーのモル数）／第３のモノマーのモル数＝０．１〜３０、好ましくは１〜１０となるように混合することが、イオン伝導経路が安定に形成され機械強度も良好であるため望ましい。上記溶媒の添加量としては、上記各モノマーの合計重量に対して、好ましくは溶媒の重量／モノマーの合計重量＝０〜２０とし、より好ましくは１〜１５とする。
【００２５】
重合反応を行う際（工程Ｃ）、重合反応によりガス発生するような場合を除き、密閉した系で重合を行うと溶媒やモノマーの蒸発に伴う組成比変化が抑制されるため好ましい。また、必要に応じて材料モノマーの析出等で系が分離しないように超音波分散等の攪拌しながら重合を行うことも好ましい。さらに重合反応を行う際、高分子骨格の配向性を向上させるため、磁場や電場を印加した状態で重合を行う方法、ラビング処理や疎水処理等の表面処理を施した基体に接触させて重合を方法が好ましく、混合物を疎水性を有する基体に接触させて重合を行うとイオン伝導経路が安定に形成されやすくなるためより好ましい。疎水性を有する基体が水の接触角で２０度以上の基板であるのが好ましく、５０度以上の基体であるとより好ましく、更に基体全体が均一な水の接触角を有していると均一にイオン伝導経路が形成されるためより望ましい。
【００２６】
前記基体としては、粒状、板状、円筒状等の形状の基体が使用できるが、板状の基体を使用するとイオン伝導経路の方向を安定にかつ均一に制御しやすくなるため好ましい。例えばこのような疎水性を有する基体としては、テトラフルオロエチレン、ポリフッ化ビニリデン、フッ化ビニリデンとヘキサフルオロプロピレンの共重合体等のフッ素樹脂やポリエチレン・ポリプロピレン樹脂等の疎水性樹脂の基体、ガラス、金属等の基体上にテトラフルオロエチレン、ポリフッ化ビニリデン、フッ化ビニリデンとヘキサフルオロプロピレンの共重合体等のフッ素樹脂フィルム、ポリエチレンフィルム、或いはポリプロピレンフィルム等を貼り付けた基体、ガラス、金属等の基体上にテトラフルオロエチレン、ポリフッ化ビニリデン、フッ化ビニリデンとヘキサフルオロプロピレンの共重合体等のフッ素樹脂、ポリエチレン樹脂、或いはポリプロピレン樹脂を塗布した基体、ガラス基板の水酸基をシリル化剤等で化学的に疎水基に置換した基体、二次電池の負極と正極間に本発明のイオン伝導体を設ける場合はテトラフルオロエチレン、ポリフッ化ビニリデン、フッ化ビニリデンとヘキサフルオロプロピレンの共重合体等のフッ素樹脂、ポリエチレン樹脂、或いはポリプロピレン樹脂を含有させて作製した電極構造体等の基体が挙げられる。
【００２７】
疎水性を有する基体を接触させる方法としては、少なくとも一面以上の面が疎水性を有する基体で構成されている重合容器を使用するのが望ましい。フィルム状の重合体を作製するような場合は、得られるフィルムの最も広い面がこの基体に接触した状態で重合するとイオン伝導経路がフィルムの厚さ方向に形成されやすくなるので好ましく、フィルムの最も広い面の両面がこの基体に接触した状態で重合するのがより好ましい。
【００２８】
また、重合反応としては、使用するモノマーに適した重合方法を用いるが、紫外線を使用した重合が任意の温度に保温した状態で重合反応が可能なため望ましい。また、電極積層体間に挿入されたポリマー前駆体の重合反応の場合は、熱エネルギーを使用した重合反応が適している。さらに、この重合反応がラジカル重合反応であると、温和な条件で重合することができるためより好ましい。
【００２９】
重合反応を行う工程以外に架橋構造を形成させる工程を行うとイオン伝導体のイオン伝導経路がより安定になり、更に機械的強度も向上するため好ましい。この架橋構造を形成させる工程としては、前記重合反応後に架橋構造を形成する方法や重合反応と同時に架橋構造の形成を行う方法が挙げられる。重合反応後に架橋構造を形成させる方法としては、架橋構造を形成し得るモノマーにより可能な方法を使用し、例えば高分子にラジカル発生剤を添加したり、紫外線、電子線、ガンマ線、熱線、プラズマ等を照射してラジカルを発生させて架橋反応を起こす方法、高分子鎖の一部の活性基を架橋剤と反応させて架橋反応を起こす方法が挙げられる。重合反応と同時に架橋構造を形成させる方法としては、上記重合反応をそのまま使用する方法であるが、使用する モノマーの混合物中に重合反応で架橋構造を形成する第３のモノマーを添加して重合反応を行うとイオン伝導体のイオン伝導経路がより安定にかつ均一に形成されるようになり好ましい。
【００３０】
以上のようにして得られたイオン伝導体を、モノマーが配向性を示す温度以上に加熱する工程（イ）を行い、次いでモノマーが配向性を示す温度以下に冷却する工程（ロ）を行うサイクルを１回以上繰り返す処理に付すことによりイオン伝導体の高分子骨格の配向性を向上させることができる。この際、前記工程（イ）におけるイオン伝導体の加熱時に該イオン伝導体を一定温度に保持するが、その温度はモノマーが配向性を示す温度より１０〜２００℃高いことが好ましく、１５〜１００℃高いことがより好ましい。
また、前記工程（ロ）におけるイオン伝導体の冷却時に該イオン伝導体を一定温度に保持するが、その温度はモノマーが配向性を示す温度より０〜１００℃低いことが好ましく、５〜５０℃低いことがより好ましい。また、前記工程（イ）及び（ロ）におけるイオン伝導体の加熱或いは冷却時に、上述したように一定温度に保持するが、その保持時間は５〜１２０分がこのましく、１０〜６０分がより好ましい。
【００３１】
更に磁場や電場を印加する方法や延伸処理を行う等の方法でイオン伝導体の高分子骨格の配向性を向上させることができる。
【００３２】
また、一般に、イオン伝導体は、使用する形状応じて重合して作製する方法が採られるが、これとは別に、得られたイオン伝導体を所定の形状に切断して使用する方法、イオン伝導体を粉砕して粉末状に加工した後結着材と共に所定の形状に成型して使用する方法等を採用することができる。
【００３３】
さらに、上記工程以外にイオン伝導体に支持体を含有させる工程を併有することも可能である。この際の支持体を含有させる方法としては、混合溶液を重合容器に挿入する際（工程Ｂ）に、支持体も重合容器内に入れて支持体ごと重合する方法、イオン伝導体や高分子化合物を粉砕して粒状にしたものと支持体を混合する、或いは支持体に担持させる方法等が挙げられる。前記支持体としては、樹脂粉末、ガラス粉末、セラミック粉末、不織布、多孔質フィルム等を使用することができる。これらの支持体の含有量を、イオン伝導体全体の好ましくは１〜５０ｗｔ％、より好ましくは１〜４０ｗｔ％に制御すると、イオン伝導体全体の機械的強度を向上させ、また支持体とイオン伝導体自体の界面を伝わるイオン伝導経路も適度に形成され、イオン伝導体自体の占有体積を低下させることが少ないので望ましい。また、これらの支持体とイオン伝導体自体の親和性や密着性を向上させるために、コロナ放電やプラズマ処理等で支持体の表面処理を行ってもよい。
【００３４】
得られたイオン伝導体の配向性の有無及び配向方向を観察する方法としては、例えば、偏光顕微鏡、Ｘ線回折測定装置、Ｘ線小角散乱測定装置或いは電子顕微鏡で直接観察する方法、赤外吸収スペクトル装置、核磁気共鳴スペクトル装置或いは熱分析測定装置で前記イオン伝導体内の特定の結晶構造部を測定し、前記方法と組み合わせて観察する方法や延伸工程と組み合わせて延伸前後の変化から観察する方法、が挙げられる。
前記偏光顕微鏡で観察する方法としては、クロスニコル偏光下で試料の明暗の変化から光学的異方性を観察して配向の有無や配向方向、更に配向状態のばらつきを測定する等の方法が挙げられる。
【００３５】
前記Ｘ線回折測定装置やＸ線小角散乱測定装置で配向性を観察する方法としては、試料にＸ線を照射して得られる回折または散乱パターンから測定する方法、すなわち、ポイントビーム状のＸ線を試料に照射したとき、スポット状のラウエパターンを形成していれば配向性を有し、配向性が減少するとリングパターンに近づき、完全なリングパターンであれば配向性が全く無くなることから測定する方法が挙げられる。
この際、スポット状のラウエパターンから配向方向についても測定することが可能である。また別の方法として、試料の異なった方向からラインビーム状のＸ線を照射して微結晶の回折または散乱ピークを測定することで試料の無配向、面配向、一軸配向、二重配向等の配向の有無・方位を測定することも可能である。
【００３６】
測定試料が微結晶相を有することが既知であれば、該測定試料のＸ，Ｙ，Ｚ軸をはじめとするあらゆる方向からＸ線を照射して回折または散乱ピークを測定した場合、特定方向から照射した時のみ特定位置に現れるピークが存在すればそのピーク位置に応じた面間隔を有する微結晶相がその照射方向に沿った方向のみに存在することになり、微結晶相が特定方向に配向していることを示唆する。例えば、測定試料に微結晶相を有することが既知であれば、まず該測定試料を粉末状態にして微結晶相の有する面間隔に相当するピーク位置を測定した後、前記測定試料そのままの状態でＸ，Ｙ，Ｚ軸をはじめとするあらゆる方向からＸ線を照射し、微結晶相の有する面間隔に相当するピークが出現する照射方向を測定する。仮に透過法（小角）で測定した時このピークが出現する方向が試料のＸ軸方向のみであれば、Ｘ軸に沿った方向へ一軸配向していることになり、ＸＹ面に沿った方向のみでピークが出現する場合はＸＹ面に平行な方向へ面配向していることになり、Ｘ軸とＹ軸方向のみでピークが出現する場合はそれぞれＸ軸とＹ軸に沿った方向へ二重配向していることになり、全方向でピークが出現したうえピーク強度比が同一である場合は全くの無秩序すなわち無配向であることになる。
【００３７】
また、全ての方向でピークが出現するものの異なる強度比で現れる場合は、配向性を有しているが全体での秩序性すなわち配向性が低いと考えられる。この照射方向を変えて強度比を測定する際は、測定試料を球形にして測定する方法や照射方向に合わせて一定形状で切り出して測定する方法等、形状を照射方向に対して一定にすることで正確に判断することができる。更に、温度変化によって試料の特定の結晶構造が変化するような場合、例えば加熱により結晶が非晶質へ変化することで特定の面間隔が消滅するような時に、その温度変化に伴うピークの変化を測定することで、内部構造のその特定部分のみの配向の観察が可能である。
【００３８】
イオン伝導体内の高分子化合物の特定の結晶部を測定する方法としては、赤外吸収スペクトル装置では結晶部特有の吸収帯の有無や強度比から測定する方法、核磁気共鳴スペクトル装置では加熱冷却に伴うピーク形状の変化から、すなわちピーク幅の広い結晶部とピーク幅の狭い非結晶部の変化から（原子結合の回転が制限されている結晶部の原子スピンのケミカルシフトは、自由回転できる非結晶部の原子に比べて隣接原子との相互配置によるシフト量が平均化されないため、ピークが多段に分裂する現象）測定する方法、熱分析測定装置では示差熱分析で結晶化と融解の熱エネルギー量から測定する方法及び粘弾性測定で高分子鎖の側鎖部や主鎖部の緩和・分散温度やそのエネルギー量から測定する方法、が挙げられる。また、これらの方法による測定と試料を延伸する操作を組み合わせて、延伸する前後や延伸方向でのピーク形状、強度変化または熱エネルギー量の変化によって配向性を観察する方法も可能である。
【００３９】
本発明での「配向性」とは、上記記載の方法等で測定することによって観察される配向性を意味し、完全な無配向でなければ配向性が弱くても本発明の配向性を有していると云えるが、配向性が強いものが好ましい。配向性の強弱すなわち配向度は、上記の偏光顕微鏡やＸ線小角散乱測定装置等で特定方向の配向の割合を測定することで判断することができる。
【００４０】
本発明での配向度を測定する方法としては、偏光顕微鏡ではクロスニコル偏光下の明暗視野の変化において明視野と暗視野の面積割合を測定することで算出し、Ｘ線小角散乱測定装置では試料のあらゆる方向からＸ線を照射して得られる特定面間隔に相当するピークの強度比から測定する。本発明において好ましい配向度は、偏光顕微鏡のクロスニコル偏光下で測定した場合、最も明視野が多くなる状態で明視野の面積割合／暗視野の面積割合が好ましくは１．２以上、より好ましくは１．５以上であり、Ｘ線小角散乱測定装置で測定した場合、特定面間隔に相当するピークの強度比で最もピーク強度が強い照射方向でのピーク強度／最もピーク強度が低くなる照射方向でのピーク強度が好ましくは１．２以上、より好ましくは２．０以上であることが望ましい。
【００４１】
イオン伝導体のイオン伝導性を測定する方法としては、イオン伝導体の一定間の抵抗値から測定する方法が挙げられる。例えば、図８に示すように、イオン伝導体７０１を２枚の電極７０２で挟み、同図に示すように結線し、２つの電極７０２間のイオン伝導体７０１の抵抗値ｒをインピーダンス測定装置７０３にて測定し、イオン伝導体７０１の厚みｄと面積Ａを測定して、式：（イオン伝導度σ）＝ｄ／（Ａ×ｒ）からイオン伝導度を算出する方法、電極間隔ｗで電極長さＬのギャップ電極をイオン伝導体に密着させてインピーダンス測定装置にて電極間の抵抗値ｒを測定し、イオン伝導体の厚みｄを測定して、式：（イオン伝導度σ）＝ｗ／（Ｌ×ｄ×ｒ）からイオン伝導度を算出する方法等が挙げられる。
【００４２】
以下では、次いで本発明で使用する各材料について詳細に説明する。
（炭素数２以下のアルキル基とポリエーテル基を含有する側鎖を有するモノマー）
炭素数２以下のアルキル基とポリエーテル基を含有する側鎖を有するモノマーとしては、下記一般式（３）で表される構造を有するモノマーであれば他の官能基を有していても良い。
【化５】
一般式（３）

上記式中、Ｒ１およびＲ２はそれぞれ水素原子あるいは炭素数２以下のアルキル基であり、好ましくは水素原子またはメチル基であると高分子化合物の配向性が向上するため望ましい。Ｒ３は少なくとも炭素数１〜４のアルキル基を有する基であり、メチル基であると高分子化合物の配向性が向上するので、より好ましい。
【００４３】
上記一般式（３）のＡ若しくはＢのいずれか一方が―（ＣＨ_２―ＣＨ_２―Ｏ）_ｍ―であり、他方が―（ＣＨ_２―ＣＨ_２（ＣＨ_３）―Ｏ）_ｎ―（ｍ、ｎは１〜３０の整数）であることが望ましい。より好ましくはｍおよびｎが、ｍ／ｎ＝０．５〜２であるであることが望ましい。
【００４４】
これらの好ましい具体例としては、メトキシ−デカエチレンオキシ−ｂｌｏｃｋ−デカプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝１０）、メトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝２０）、メトキシ−トリアコンタエチレンオキシ−ｂｌｏｃｋ−トリアコンタプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝３０）、メトキシ−アイコサプロピレンオキシ−ｂｌｏｃｋ−アイコサエチレンオキシ−アクリレート（プロピレンオキサイド数、エチレンオキサイド数＝２０）、メトキシ−トリアコンタプロピレンオキシ−ｂｌｏｃｋ−デカエチレンオキシ−アクリレート（プロピレンオキサイド数＝３０、エチレンオキサイド数＝１０）、メトキシ−ペンタエチレンオキシ−ｂｌｏｃｋ−ペンタデカプロピレンオキシ−アクリレート（エチレンオキサイド数＝５、プロピレンオキサイド数＝１５）等が挙げられる。
【００４５】
（炭素数６以上のアルキル基とポリエーテル基を含有する側鎖を有するモノマー）
炭素数６以上のアルキル基とポリエーテル基を含有する側鎖を有するモノマーとしては、下記一般式（４）で表される構造を有するモノマーであれば他の官能基を有していても良い。
【化６】
一般式（４）

上記式中のＲ４およびＲ５はそれぞれＨ又は炭素数２以下のアルキル基であり、好ましくは水素原子（Ｈ）又はメチル基である、この場合、高分子化合物の配向性が向上する。またＲ６は、少なくとも炭素数６以上のアルキル基を有する基であればその他の官能基を有していても良く、また直鎖状でも分岐状のアルキル基でも良い。中でも、イオン伝導経路の形成の面で炭素数６〜２２の直鎖状のアルキル基や炭素数６〜２２の直鎖状のアルキル基を有するアルキルベンジル基を含有すものが好ましく、炭素数８〜１８の直鎖状のアルキル基がより好ましい。
【００４６】
上記一般式（４）中のＸは、少なくともポリエーテル基、すなわちＣ−Ｏ−Ｃで表されるエーテル構造を２以上有する基を含有する基であればその他の官能基を有していても良く、また直鎖状でも分岐状の構造でも良い。中でも、イオン伝導経路の形成の面で−（ＣＨ_２ −ＣＨ_２ −Ｏ）_ｋ −（ｋ＝１〜４０）を少なくとも含有する基であると更に良い。
また、前記一般式（４）中のＸのポリエーテル基とＲ６ のアルキル基の比率が、Ｒ６のアルキル基の分子量／Ｘのポリエーテル基の分子量で、０．０５〜３．０の範囲であるのが好ましく、０．１〜１．０の範囲であるとイオン伝導経路が安定に配向するのでより好ましい。Ｘが−（ＣＨ_２−ＣＨ_２ −Ｏ）_ｎ −を少なくとも含有する場合は、Ｘの−（ＣＨ_２ −ＣＨ_２−Ｏ）_ｋ−とＲ６のアルキル基の比率が、Ｒ３のアルキル基の炭素数／−（ＣＨ_２ −ＣＨ_２ −Ｏ）_ｋ−のｋ数で、０．０５〜１０．０の範囲が好ましく、０．５〜５．０の範囲がより好ましい。
【００４７】
これらの好ましい具体例としては、テトラエチレングリコールｎ−オクチルエーテルメタクリレート、ヘキサエチレングリコールｎ−ドデシルエーテルメタクリレート、オクタエチレングリコールｎ−ヘキサデシルエーテルメタクリレート、エイコサエチレングリコールｎ−オクタデシルエーテルメタクリレート、テトラエチレングリコールｎ−オクチルエーテルアクリレート、ヘキサエチレングリコールｎ−ドデシルエーテルアクリレート、オクタエチレングリコールｎ−ヘキサデシルエーテルアクリレート、エイコサエチレングリコールｎ−オクタデシルエーテルアクリレート、ヘキサエチレングリコールｎ−ノニルフェニルエーテルメタクリレート、エイコサエチレングリコールｎ−ノニルフェニルエーテルメタクリレート等が挙げられる。
【００４８】
（ポリエーテル基、シアノ基、アミノ基、アミド基及びカーボネート基から成る群から選択される少なくとも一種以上の極性基を側鎖に有するモノマー）
本発明の製造方法に使用するポリエーテル基、シアノ基、アミノ基、アミド基及びカーボネート基から成る群から選択される一種類以上の極性基を側鎖に有するモノマーは、下記一般式（５）で表される構造を有するモノマーであれば他の官能基を有していても良い。
【化７】
一般式（５）

【００４９】
上記一般式（５）中、Ｒ７およびＲ８は、それぞれＨ又は炭素数２以下のアルキル基、好ましくは水素原子（Ｈ）またはメチル基である。後者の場合、高分子化合物の配向性が向上する。Ｙは、ポリエーテル基、シアノ基、アミノ基、アミド基及びカーボネート基からなる群から選択される少なくとも一種類の極性基を有する基であればその他の官能基を有していても良く、また直鎖状でも分岐状のアルキル基でも良い。また、イオン伝導体をリチウム電池等で使用する際は、ポリエーテル基がリチウム等との反応が起こりにくいため好ましく、中でも、−（ＣＨ_２−ＣＨ_２ −Ｏ）_ｎ −Ｚ、−（ＣＨ_２ −ＣＨ（ＣＨ_３ ）−Ｏ）_ｎ−Ｚ、−（ＣＨ_２ −ＣＨ_２ −Ｏ）_ｍ −（ＣＨ_２ −ＣＨ（ＣＨ_３）−Ｏ）_ｎ −Ｚ、−（ＣＨ_２ −ＣＨ（ＣＨ_３ ）−Ｏ）_ｍ −（ＣＨ_２−ＣＨ_２ −Ｏ）_ｎ −Ｚ、−（ＣＨ_２ −ＣＨ_２ −Ｏ）_ｌ−（ＣＨ_２ −ＣＨ（ＣＨ_３ ）−Ｏ）_ｍ −（ＣＨ_２ −ＣＨ_２−Ｏ）_ｎ −Ｚ及び−（ＣＨ_２ −ＣＨ（ＣＨ_３ ）−Ｏ）_ｌ −（ＣＨ_２−ＣＨ_２ −Ｏ）_ｍ −（ＣＨ_２ −ＣＨ（ＣＨ_３ ）−Ｏ）_ｎ−Ｚからなる群（ｌ，ｍ，ｎは整数、Ｚは水素原子または炭素数１〜４のアルキル基）から選択される少なくとも一種類の基を含有する基であるのが好ましく、−（ＣＨ_２−ＣＨ_２ −Ｏ）_ｎ −Ｚ（ｎ＝２〜１００、ＺはＨ又は炭素数１〜４のアルキル基）であるのがより好ましい。
【００５０】
これらの好ましい具体例としては、テトラエチレングリコールメチルエーテルメタクリレート、ヘキサエチレングリコールエチルエーテルメタクリレート、オクタエチレングリコールｎ−ブチルエーテルメタクリレート、エイコサエチレングリコールメチルエーテルメタクリレート、テトラエチレングリコールエチルエーテルアクリレート、ヘキサエチレングリコールメチルエーテルアクリレート、オクタエチレングリコールメチルエーテルアクリレート、エイコサエチレングリコールエチルエーテルアクリレート等が挙げられる。
【００５１】
（架橋構造を形成し得るモノマー）
架橋構造を形成し得る第３のモノマーとしては、水素結合やイオン対を形成して結合するイオン結合のような物理的な結合を形成するモノマーと共有結合からなる化学的な結合を形成するモノマーが挙げられるが、水素結合等の物理的結合は温度変化やｐＨの変化等によって結合が切断して結合状態が変化することもあるため、このような変化の少ない化学的に結合した共有結合を形成するモノマーが好ましい。またこのモノマーとしては、３以上の他のモノマーと重合し得る重合官能基を有しているものが好ましく、重合反応（工程Ｃ）のみで３以上のモノマーと重合し得る重合官能基を有するものがより好ましい。モノマーの重合官能基としては、縮合重合、重縮合、開環重合等によりエステル結合、アミド結合、エーテル結合、ウレタン結合等の共有結合の形成が可能な基、付加重合し得るビニル基等が挙げられる。中でも、ビニル基または環状エーテルが好ましく、ビニル基またはエポキシドがより好ましく、ビニル基が更に好ましい。特に、ビニル基を２以上有するジビニル化合物、トリビニル化合物が望ましい。ビニル基としては、ビニル基、アリル基、アクリル基、メタクリル基、クロトン基等が挙げられ、エポキシドとしては、エチレンオキサイド、プロピレンオキサイド、グリシジルエーテル等のアルキレンオキシドが挙げられる。
【００５２】
上述したものの中でも、架橋構造を形成し得るモノマーが下記の一般式（６）で表されるモノマーであるのが特に好ましい。
【化８】
一般式（６）

【００５３】
上記一般式（６）中の、Ｒ９乃至Ｒ１４は、それぞれ水素原子またはアルキル基であり、水素原子またはメチル基 が好ましい。Ｚ１は架橋結合を形成する基であり、特に限定は無く、一般式（６）のように両端が結合し得るものであれば特に限定はないが、−ＣＯ−，−ＯＣＯＯ−，−ＣＯＮＨ−，−ＣＯＮＲ−，−ＯＣＯＮＨ−，−ＮＨ−，−ＮＨＲ−，−ＳＯ−，−ＳＯ_２−，（Ｒはアルキル基）及びエーテル基からなる群から選ばれる少なくとも一種類の結合若しくは官能基を有するものが好ましく、エーテル基を２以上有する基、すなわちポリエーテル基を有するものがより好ましい。
【００５４】
このような具体例としては、アクリル酸ビニル、エチレングリコールジメタクリレート、ヘキサエチレングリコールジアクリレート、トリデカエチレングリコールジアクリレート、エイコサエチレングリコールジメタクリレート、Ｎ，Ｎ’−メチレンビスアクリルアミド、ジエチレングリコールジメタクリレート、ジエチレングリコールビスアリルカーボネート、１，４−ブタンジオールジアクリレート、ペンタデカンジオールジアクリレート、１，１０−デカンジオールジメタクリレート、ネオペンチルグリコールジメタクリレート、ジアリルエーテル、ジアリルサルファイド、グリセリンジメタクリレート、２−ヒドロキシ−３−アクリロルイロキシプロピルメタクリレート、２−メタクロイロキシエチルアシッドホスフェート、ジメチロール−トリシクロデカンジアクリレート、ヒドロキシピバリン酸ネオペンチルグリコールジアクリレート、ビスフェノールＡジアクリレート、ビスフェノールＡのエチレンオキサイド付加物ジアクリレート、ポリテトラメチレングリコールジメタクリレート、ポリ（エチレングリコール−テトラメチレングリコール）ジメタクリレート、ポリ（エチレングリコール−テトラメチレングリコール）ジアクリレート、ポリ（プロピレングリコール−テトラメチレングリコール）ジメタクリレート、ポリ（プロピレングリコール−テトラメチレングリコール）ジアクリレート、ポリエチレングリコール−ポリプロピレングリコール−ポリテトラメチレングリコール）ジメタクリレート、ポリエチレングリコール−ポリプロピレングリコール−ポリテトラメチレングリコール）ジアクリレート等が挙げられる。
【００５５】
（溶媒）
図２に徴して先に述べた本発明のイオン伝導体の製造方法で使用する溶媒としては、イオン伝導体の高分子化合物の可塑剤として機能する溶媒であり、重合反応を阻害しない溶媒であれば上記各モノマーと電解質が完全に溶解しなくても使用することができるが、上記各モノマーと電解質を溶解し得る溶媒が好ましく、個々のモノマーや電解質のみを溶解する溶媒の混合溶液も望ましく、更に各モノマーと電解質を溶解しかつ重合で生成する高分子化合物と親和性が高いものが均一な高分子化合物を形成することができるためより望ましい。また、後の工程でこの溶媒を除去するような場合は、揮発性の高い溶媒を選択するのが望ましい。
【００５６】
そのような溶媒の具体例としては、メタノール、エタノール、１−プロパノール、２−プロパノール、１−ブタノール、エチレングリコール、グリセリン、ジエチルエーテル、ジイソプロピルエーテル、テトラヒドロフラン、テトラヒドロピラン、１，２−メトキシエタン、ジエチレングリコールジメチルエーテル、アセトン、エチルメチルケトン、シクロヘキサノン、酢酸エチル、酢酸ブチル、プロピレンカーボネート、エチレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネート、ホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド、１，３−ジメチル−２−イミダゾリジノン、Ｎ−メチルピロリドン、アセトニトリル、プロピオニトリル、スリシノニトリル、ベンゾニトリル、エチレンジアミン、トリエチレンアミン、アニリン、ピリジン、ピペリジン、モルホリン、塩化メチレン、クロロホルム、１，２−ジクロロエタン、クロロベンゼン、１−ブロモ−２−クロロエタン、ニトロメタン、ニトロベンゼン、ｏ−ニトロトルエン、ジエトキシエタン、１，２−ジメトキシエタン、γ−ブチロラクトン、ジオキソラン、スルホラン、ジメチルサルファイド、ジメチルサルオキシド、ジメトキシエタン、ギ酸メチル、３−メチル−２−オキサゾリジノン、２−メチルテトラヒドロフラン、二酸化イオウ、塩化ホスホリル、塩化チオニル、塩化スルフリル等が挙げられる。なお、これらの溶媒は単独で使用しても、或いはそれらの二種類或いはそれ以上を混合して使用しても良い。
【００５７】
また、上記各モノマーが完全に溶解しない溶媒を使用する場合は、界面活性剤等の分散剤をこの溶媒中に添加しておく方法も可能である。この際の分散剤の添加量は溶媒に対して４重量％以下、好ましくは３重量％以下にしておくのが望ましい。分散剤を４重量％より多く添加すると、イオン伝導経路の形成時の配向性が低下しやすくなり、また洗浄しても残存する分散剤の量が多くなるので分散剤がイオン伝導を阻害しやすくなり、イオン伝導性の低下が起こりやすくなる。
【００５８】
（重合開始剤）
本発明のイオン伝導体の製造方法で使用する重合開始剤としては、重縮合、付加重合、開環重合等の重合方式やラジカル重合、カチオン重合、アニオン重合等の反応機構によって適当な重合開始剤を選択して使用すれば良い。重合開始剤の具体例としては、アゾビスイソブチロニトリルなどのアゾ化合物、過酸化ベンゾイルなどの過酸化物、過硫酸カリウム、過硫酸アンモニウム、ケトン化合物やメタロセン化合物の光吸収分解化合物等、Ｈ_２ＳＯ_４ ，Ｈ_３ ＰＯ_４ ，ＨＣｌＯ_４ ，ＣＣｌ_３ＣＯ_２ Ｈなどの酸、ＢＦ_３ ，ＡｌＣｌ_３ ，ＴｉＣｌ_４ ，ＳｎＣｌ_４などのＦｒｉｅｄｅｌ−Ｃｒａｆｔｓ触媒、Ｉ_２ ，（Ｃ_６ Ｈ_５ ）_３ ＣＣｌ、アルカリ金属化合物、マグネシウム化合物等が挙げられる。これらの重合開始剤のモノマーに対する添加量は、全モノマーの重量に対してモノマー比で０．００１〜１０重量％の範囲がモノマーの重合効率が高くまた重合度も大きくなり機械的強度が良好になるため好ましく、０．０１〜５重量％の範囲がより好ましい。
【００５９】
（電解質）
本発明のイオン伝導体の製造方法で使用する電解質としては、リチウムイオン、ナトリウムイオン、カリウムイオン、テトラアルキルアンモニウムイオン等の陽イオンと、ルイス酸イオン（ＢＦ_４ ⁻、ＰＦ_６ ⁻、ＡｓＦ_６ ^―、ＣｌＯ_４ ⁻、ＣＦ_３ ＳＯ_３ ⁻、（ＣＦ_３ ＳＯ_２）_２ Ｎ⁻、（ＣＦ_３ ＳＯ_２ ）_３ Ｃ⁻、ＢＰｈ_４ ⁻（Ｐｈ：フェニル基））とから成る塩、水酸化リチウム、水酸化ナトリウム、水酸化カリウム等のアルカリ金属の水酸化物およびこれらの混合物が挙げられる。中でも、リチウム塩が好ましい。
【００６０】
本発明のイオン伝導体の製造方法により以上述べた材料を使用して製造されるイオン伝導体の骨格を構成する高分子化合物の組成や化学構造の解析は、赤外吸収スペクトル装置や可視紫外吸収スペクトル装置で結合や原子団の組成を解析する方法、核磁気共鳴スペクトル装置、電子スピン共鳴スペクトル装置や旋光分散装置で結合や原子団の組成及び構造を解析する方法、マススペクトル装置で原子団の組成を解析する方法、液体クロマトグラフィー・ガスクロマトグラフィー等の各種クロマトグラフィーで原子団の組成や重合度等の構造を測定する方法、官能基の直接滴定法等で同定・定量する方法、で行うことができる。この際、測定試料は測定方法に応じてそのままで行ったり化学的に分解等の処理を行った上で測定する。
【００６１】
（本発明の二次電池の製造方法）
本発明の二次電池の製造方法について説明する。本発明の二次電池の製造方法は、典型的には、上述したイオン伝導体の製造方法で作製したイオン伝導体を、負極面と正極面とを結ぶ方向にイオン伝導度が最も高くなるように、負極と正極間に接した状態で設け、出力端子を取り出し外装材で密閉することによって二次電池を作製する方法である。
【００６２】
本発明における二次電池の具体的な形状としては、例えば、扁平形、円筒形、直方体形、シート形などがある。又、二次電池の構造としては、例えば、単層式、多層式、スパイラル式などがある。その中でも、スパイラル式円筒形の電池は、負極と正極の間にセパレータを挟んで巻くことによって、電極面積を大きくすることができ、充放電時に大電流を流すことができるという特徴を有する。また、直方体形やシート形の電池は、複数の電池を収納して構成する機器の収納スペースを有効に利用することができる特徴を有する。
【００６３】
図５は、単層式シート型二次電池の具体的一例の構成を模式的に示す略断面図である。図５において、４０１はイオン伝導体、４０２は負極集電体、４０３は負極活物質（負極材料）、４０４は負極、４０５は正極活物質（正極材料）、４０６は正極集電体、４０７は正極、４０８は外装材、４０９は電極積層体、をそれぞれ示す。
図６は単層式扁平形（コイン形）二次電池の具体的一例の構成を模式的に示す略断面図である。この二次電池は、基本的には図５と同様な構成である。尚、図６において、５０１は負極、５０２はイオン伝導体、５０３は正極、５０４は負極缶（負極端子）、５０５は正極缶（正極端子）、５０６はガスケット、をそれぞれ示す。
図には、単層式二次電池しか示していないが、負極と正極の間にイオン伝導体をはさみ多層に積層した多層式二次電池であってもよい。
【００６４】
本発明のイオン伝導体を用いることによって、負極と正極の間で電解液を固形化することができるので、液漏れがなく、電池の密閉も容易なことから、電池の外装材の厚みを薄くすることができ、自由な形状の二次電池を容易に作製することができる。
【００６５】
図５に示す二次電池は、上述したイオン伝導体を使用し、該イオン伝導体を負極４０４と正極４０７の間に挟んだ構造の電極積層体４０９を形成し、得られた電極積層体４０９を外装材４０８で密閉することにより作製できる。電極積層体４０９を形成す方法の具体例を以下に述べる。
【００６６】
（電極積層体４０９の形成方法１）
負極４０４表面若しくは正極４０７表面、或いは負極４０４と正極４０７の両表面に、先に述べたイオン伝導体の製造方法で、薄膜状のイオン伝導体を形成する。ついで負極４０４と正極４０７をイオン伝導体の設けた面を対向面として密着させるか、或いは負極４０４と正極４０７の間に更に同様の薄膜状のイオン伝導体を挟んで密着させ電極積層体４０９を形成する。この際、最初に形成したイオン伝導体と電極との密着性の向上を図るため、前記イオン伝導体と負極４０４との間及び正極４０７との間或いは前記イオン伝導体と負極４０４または正極４０７との間に形成したイオン伝導体との間に、イオン伝導体の原料であるポリマー前駆体を挿入し、密着後加熱することで挿入したポリマー前駆体を重合させ、イオン伝導体からなる接着層を形成するのが好ましい。さらに、前記接着層中の高分子骨格の配向性を向上させるため、作製した電極積層体を、前記ポリマー前駆体に含まれるモノマーが配向性を示す温度以上の温度に加熱する工程（イ）を行い、次いで前記モノマーが配向性を示す温度以下に冷却する工程（ロ）を行うサイクルを１回以上繰り返す処理に付すのが好ましい。この際、前記工程（イ）における前記電極積層体の加熱時に該電極積層体を一定温度に保持するが、その温度は前記モノマーが配向性を示す温度より１０〜２００℃高いことが好ましく、１５〜１００℃高いことがより好ましい。また、前記工程（ロ）における前記電極積層体の冷却時に該電極積層体を一定温度に保持するが、その温度は前記モノマーが配向性を示す温度より０〜１００℃低いことが好ましく、５〜５０℃低いことがより好ましい。また、前記工程（イ）及び（ロ）における前記電極積層体の加熱或いは冷却時に、上述したように一定温度に保持するが、その保持時間は５〜１２０分が好ましく、１０〜６０分がより好ましい。
【００６７】
（電極積層体４０９の形成方法２）
先に述べたイオン伝導体の製造方法で作製したフィルム状のイオン伝導体の両面に負極４０４と正極４０７を対向して密着させるように、負極４０４と正極４０７でイオン伝導体を挟んで電極積層体４０９を形成する。この際、負極４０４と正極４０７の電極活物質（４０３、４０５）内の空隙にもイオン伝導体が入り込むようにすると、充放電効率の向上につながるため、負極４０４と正極４０７の表面に同様のイオン伝導体を形成するのが好ましい。この際、上記イオン伝導体と電極との密着性の向上を図るためにも、負極４０４と正極４０７を該イオン伝導体を挟んで密着させる際に、該イオン伝導体と負極４０４との間及び正極４０７との間にイオン伝導体の原料であるポリマー前駆体を挿入し、密着後加熱することで挿入したポリマー前駆体を重合させ、イオン伝導体からなる接着層を形成するのが好ましい。さらに、前記接着層中の高分子骨格の配向性を向上させるため、作製した電極積層体を、前記ポリマー前駆体に含まれるモノマーが配向性を示す温度以上に加熱する工程（イ）を行い、次いで前記モノマーが配向性を示す温度以下に冷却する工程（ロ）を行うサイクルを１回以上繰り返す処理に付すのが好ましい。この際、前記工程（イ）における前記電極積層体の加熱時に該電極積層体を一定温度に保持するが、その温度は前記モノマーが配向性を示す温度より１０〜２００℃高いことが好ましく、１５〜１００℃高いことがより好ましい。また、前記工程（ロ）における前記電極積層体の冷却時に該電極積層体を一定温度に保持するが、その温度は前記モノマーが配向性を示す温度より０〜１００℃低いことが好ましく、５〜５０℃低いことがより好ましい。また、前記工程（イ）及び（ロ）における前記電極積層体の加熱或いは冷却時に、上述したように一定温度に保持するが、その保持時間は５〜１２０分が好ましく、１０〜６０分がより好ましい。
【００６８】
図６に示す扁平型（コイン型）の二次電池では、正極材料層（活物質層）を備えた正極５０３と負極材料層（活物質層）を備えた負極５０１が少なくともイオン伝導体５０２を介して積層されており、この積層体が正極端子としての正極缶５０５内に正極側から収容され、負極側が負極端子としての負極キャップ５０４により被覆されている。そして正極缶内の他の部分にはガスケット５０６が配置されている。
【００６９】
図６に示した二次電池の組み立ては、例えば、以下のようにして行う。
（１）負極（５０１）と正極（５０３）の間にイオン伝導体（５０２）を挟持させた電極積層体を前述した電極積層体の形成方法１または２の方法で形成し、正極缶（５０５）に組み込む。
（２）負極キャップ（５０４））とガスケット（５０６）を組み立てる。
（３）上記（２）で得られたものを、かしめることによって、電池は完成する。
尚、上述した電池の材料調製及び電池の組立は、水分が十分除去された乾燥空気中、又は乾燥不活性ガス中で行うのが望ましい。
【００７０】
以下に、図５を参照して、二次電池の構成部材についてより詳細な説明を行う。
（負極）
負極４０４は集電体４０２と活物質層４０３から構成されている。尚、本発明では、“活物質”とは二次電池における充電および放電の電気化学的反応（充放電反応の繰返し）に関与する物質を意味する。
【００７１】
本発明の二次電池が、リチウムイオンの酸化―還元反応を利用したリチウム二次電池の場合、負極の活物質層に用いる材料としては、充電時にリチウムを保持するもので、リチウム金属、リチウムと電気化学的に合金化する金属、リチウムをインターカレートする炭素材料もしくは遷移金属化合物、が挙げられる。上記リチウムと電気化学的に合金化する金属としては、Ｂｉ，Ｉｎ，Ｐｂ，Ｓｉ，Ａｇ，Ｓｒ，Ｇｅ，Ｚｎ，Ｓｎ、Ｃｄ、Ｓｂ、Ｔｌ、Ｈｇ等が挙げられ、金属が非晶質相を有する合金であるとイオン伝導体との密着性が良好であるため好ましく、Ｓｎの非晶質合金がより好ましい。前記遷移金属化合物としては、遷移金属酸化物、遷移金属窒化物、遷移金属硫化物、遷移金属炭化物などが挙げられる。これらの遷移金属化合物の遷移金属元素としては、例えば、部分的にｄ殻あるいはｆ殻を有する元素であるところの、Ｓｃ，Ｙ，ランタノイド，アクチノイド，Ｔｉ，Ｚｒ，Ｈｆ，Ｖ，Ｎｂ，Ｔａ，Ｃｒ，Ｍｏ，Ｗ，Ｍｎ，Ｔｃ，Ｒｅ，Ｆｅ，Ｒｕ，Ｏｓ，Ｃｏ，Ｒｈ，Ｉｒ，Ｎｉ，Ｐｄ，Ｐｔ，Ｃｕ，Ａｇ，Ａｕが挙げられる。特に、第１遷移系列金属であるＴｉ，Ｖ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，及びＣｕが好適である。
【００７２】
上記負極活物質が粉末状であれば、これに結着剤を混合し、場合によっては導電補助材も添加して集電体上に塗布やプレス等で負極活物質層４０３を形成し、箔や板状であれば集電体上にプレス等で貼り付けて負極を作成する。また、メッキや蒸着法で集電体上に上記材料の薄膜を形成する方法を用いることもできる。前記蒸着方法としては、ＣＶＤ（Ｃｈｅｍｉｃａｌ Ｖａｐｏｒ Ｄｅｐｏｓｉｔｉｏｎ）、電子ビーム蒸着、スパッタリング、などの方法が挙げられる。いずれのリチウム二次電池用の負極も減圧下で十分に乾燥することが必要である。
【００７３】
負極４０４の活物質層４０３の形成に使用する上記結着剤としては、例えば、ポリエチレンやポリプロピレンなどのポリオレフィン、又はポリフッ化ビリニデンやテトラフルオロエチレンポリマーのようなフッ素樹脂、ポリビニルアルコール、セルロース、又はポリアミドが挙げられるが、負極４０４上でイオン伝導体を直接形成するような場合には、フッ素樹脂等の疎水性を有する結着剤を使用すると高分子化合物の配向性がより向上するため望ましい。
【００７４】
負極４０４の集電体４０２は、充放電時の電極反応で消費する電流を効率よく供給するあるいは発生する電流を集電する役目を担っている。したがって、集電体４０２の構成材料としては、電導度が高く、かつ、電池反応に不活性な材質が望ましい。そうした好ましい材料としては、ニッケル、チタニウム、銅、アルミニウム、ステンレススチール、白金、パラジウム、金、亜鉛、各種合金、およびこれら材料の二種類またはそれ以上からなる複合金属材料が挙げられる。集電体４０２の形状としては、例えば、板状、箔状、メッシュ状、スポンジ状、繊維状、パンチングメタル、エキスパンドメタルなどの形状が採用できる。
【００７５】
（正極）
正極４０７は集電体４０６と活物質層４０５から構成されている。本発明の二次電池がリチウムイオンの酸化―還元反応を利用したリチウム二次電池の場合、正極４０７の活物質層４０５に用いる材料としては、放電時にリチウムを保持するもので、リチウムをインターカレートする遷移金属酸化物、遷移金属窒化物、遷移金属硫化物、などの遷移金属化合物が挙げられる。これらの遷移金属化合物の遷移金属元素としては、例えば、部分的にｄ殻あるいはｆ殻を有する元素であるところの、Ｓｃ，Ｙ，ランタノイド，アクチノイド，Ｔｉ，Ｚｒ，Ｈｆ，Ｖ，Ｎｂ，Ｔａ，Ｃｒ，Ｍｏ，Ｗ，Ｍｎ，Ｔｃ，Ｒｅ，Ｆｅ，Ｒｕ，Ｏｓ，Ｃｏ，Ｒｈ，Ｉｒ，Ｎｉ，Ｐｄ，Ｐｔ， Ｃｕ，Ａｇ，Ａｕが挙げられる。特に、第１遷移系列金属であるＴｉ，Ｖ，Ｃｒ，Ｍｎ，Ｆｅ，Ｃｏ，Ｎｉ，及びＣｕが好適である。電池組み立て時にリチウムを含有していない負極活物質を使用する場合は、正極活物質としては、リチウムをあらかじめ含有したリチウム遷移金属酸化物等の化合物を使用するのが好ましい。
【００７６】
正極４０７は、集電体４０６、正極活物質、導電補助材、結着剤などで構成される。正極４０７は、正極活物質、導電補助材、および結着剤などを混合したものを、集電体４０６の上に配置し成形して作製される。
【００７７】
正極４０７に使用する前記導電補助剤としては、黒鉛、ケッチェンブラックやアセチレンブラックなどのカーボンブラック、ニッケルなどの金属微粉末などが挙げられる。正極４０７に使用する前記結着剤としては、例えば、ポリエチレンやポリプロピレンなどのポリオレフィン、又はポリフッ化ビリニデンやテトラフルオロエチレンポリマーのようなフッ素樹脂、ポリビニルアルコール、セルロース、又はポリアミドが挙げられるが、正極上でイオン伝導体を直接形成するような場合には、フッ素樹脂等の疎水性を有する結着剤を使用すると高分子化合物の配向性がより向上するため望ましい。
【００７８】
集電体４０６は、充放電時の電極反応で消費する電流を効率よく供給するあるいは発生する電流を集電する役目を担っている。したがって、集電体４０６の構成材料としては、電導度が高く、かつ、電池反応に不活性な材質が望ましい。そうした好ましい材料としては、ニッケル、チタニウム、アルミニウム、ステンレススチール、白金、パラジウム、金、亜鉛、各種合金、およびこれら材料の二種類またはそれ以上からなる複合金属材料が挙げられる。集電体４０６の形状としては、例えば、板状、箔状、メッシュ状、スポンジ状、繊維状、パンチングメタル、エキスパンドメタルなどの形状が採用できる。
【００７９】
（絶縁パッキング）
ガスケット（５０６）の材料としては、例えば、フッ素樹脂，ポリオレフィン樹脂、ポリアミド樹脂，ポリスルフォン樹脂，各種ゴムが使用できる。
（外装材・電池ハウジング）
二次電池において各部材を収容する電池ハウジングは、図６に示す例では、電池の正極缶５０５および負極キャップ５０４から構成される。図６に示す例では正極缶５０５および負極キャップ５０４が、電池ハウジング（ケース）と出入力端子を兼ねているため、ステンレススチールが好ましく用いられる。また図５に示す例のように、電池の外装材４０８がハウジングを兼用しない場合には、板状およびフィルム状のプラスチック材、金属箔もしくは蒸着金属膜をプラスチックフィルムでラミネートしたラミネートフィルムなどのプラスチックと金属の複合材、などが好適に用いられる。本発明の二次電池がリチウム二次電池である場合には、外装材としては、水蒸気やガスを透過しない材料を用いることがより好ましく、水蒸気の侵入経路をふさぐ密閉化できることが肝要である。
【００８０】
【実施例】
以下に示す実施例により本発明を更に詳細に説明する。但し、これらの実施例は例示的なものであり、本発明はこれらの実施例により何ら限定されるものではない。尚、以下実施例における量に係る“部”は、重量部を意味する。
【００８１】
【実施例１】
本実施例ではイオン伝導体を、以下に述べるようにして作製した。
（１）イオン伝導体の作製：
第１のモノマーであるポリエーテル基を側鎖に有するモノマーとしてメトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝２０）を用いた。まず、配向性を示す温度を測定した。示差熱分析（ＤＳＣ）によって測定される前記第１のモノマーの融点を測定したところ１２℃付近であった（図３）。温度変化させてこのモノマーの配向性をクロスニコル偏光下において観察すると、１２℃以下の場合、暗視野から明視野への変化が観察された。したがってこの第１のモノマーの場合、配向性を示す温度は１２℃であることが判った。この第１のモノマーを１５０部、第２のモノマーとしてメトキシトリプロピレングリコーアクリレート１０部、架橋剤としてポリ（エチレングリコールテトラメチレングリコールジメタクリレート１．８部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン１部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液３０７０部を添加し、ポリマー前駆体（Ｌ１）を得た。そして、このポリマー前駆体（Ｌ１）をフッ素樹脂層を片面に形成した石英板２枚とテフロン（登録商標）製のスペーサー（厚さ５０μｍ）で形成したセル（図５の重合容器３０１）内に挿入した。重合容器を−２０℃に設定した恒温槽に入れ前記ポリマー前駆体中のモノマーを配向させた後、１０ｍＷ／ｃｍ^２の紫外線を１時間照射して重合反応と架橋反応を行った後、前記恒温槽の温度を２５℃にしイオン伝導体（横１０ｃｍ×縦６ｃｍ×厚み５０μｍ）を得た。
【００８２】
その後、前記恒温槽の温度を毎分１℃の割合で上昇させ、４０℃になったらその温度で１０分間保温する加熱工程を行い、次いで前記恒温槽の温度を毎分１℃の割合で下降させ、−２０℃になったらその温度で１０分間保温する冷却工程を行うサイクルを１サイクルとして、このサイクルを５回繰り返した後、前記恒温槽の温度を２５℃にした。
このサイクル処理工程の前後において、得られたイオン伝導体を以下に示すように、偏光顕微鏡、粘弾性測定装置（ＤＭＳ）とＸ線小角散乱測定装置で配向性の測定を行った。また、イオン伝導性についても測定した。
【００８３】
（２）配向性の測定−偏光顕微鏡：
得られたフィルム状のイオン伝導体を偏光顕微鏡を用いてクロスニコル偏光下でフィルム面の観察を行った。上記加熱工程―冷却工程のサイクル繰り返し処理前後とも、暗視野から明視野への変化がフィルム面全面で均一に観察された。
【００８４】
（３）配向性の測定−Ｘ線小角散乱：
前記イオン伝導体を粘弾性測定装置（ＤＭＳ）にて高分子鎖の側鎖部の緩和温度を測定し、Ｘ線小角散乱測定装置でフィルム面に対して平行方向（Ｘ軸，Ｙ軸方向）や厚さ方向（Ｚ軸）を含むあらゆる方向から、側鎖部の緩和温度以下である室温で、それぞれ測定を行った。なおこの測定の際は、測定方向に対して試料形状が一定なるように調整して測定を行った。
その結果、フィルム面に対して厚さ方向（Ｚ軸方向）で測定したとき、図７のピークが出現し、他の方向から測定した際、この位置のピーク強度はＺ軸方向の時のピーク強度よりかなり小さかった。この際、Ｚ軸方向のピーク強度は、最もピーク強度の弱い方向に対して、ピーク強度比で６倍（上記加熱工程―冷却工程のサイクル繰り返し処理前）および８倍（上記加熱工程―冷却工程のサイクル繰り返し処理後）であった。また、フィルム面のＸ軸に沿った方向（Ｘ軸方向）で図７のピーク位置とは異なる位置でピークが出現し、この位置のピークはフィルム面に沿った方向（ＸＹ面方向）以外では出現しなかった。この際、ピーク強度はＸ軸方向が最も強く、他のＸＹ面方向（Ｘ軸方向を除く）の最もピーク強度の弱い方向に対してピーク強度比で９倍（上記加熱工程―冷却工程のサイクル繰り返し処理前）および１１倍（上記加熱工程―冷却工程のサイクル繰り返し処理後）であった。
次いで、測定試料を側鎖部の緩和温度以上の１００℃に加熱してフィルム面に対して厚さ方向（Ｚ軸）から同様に測定したところ、図７のピークが温度上昇とともにピーク強度が減少するという変化が観察され、加熱により側鎖部の図１（ａ）のような配向が崩れてくる結果となった。この様な変化はフィルム面に対して垂直方向以外ではほとんど見られなかった。
以上の結果から、得られたイオン伝導体は高分子鎖の主鎖部がフィルム面に平行に側鎖部が厚さ方向に配向していると考えられる結果となった。また、上記加熱工程―冷却工程のサイクル繰り返し処理後では、その処理前に比べ主鎖部・側鎖部の配向性が強まる結果となった。
これらの結果は下記表１に示した。
【００８５】
（４）イオン伝導性の測定：
図８に示すように、上記（１）で得られたフィルム状のイオン伝導体（７０１）を、二つのステンレス製の電極７０２で挟み、ミリオームメータからなるインピーダンス測定装置７０３に結線し、両電極７０２間のイオン伝導体７０１の抵抗値を、前記インピーダンス測定装置７０３により測定した。イオン伝導体７０１の抵抗値の測定は、入力電圧が０．１Ｖで１キロヘルツのサイン波の測定信号でインピーダンス測定をし、抵抗値ｒを求め、イオン伝導体７０１の厚みｄと面積Ａを測定し、式（イオン伝導度σ）＝ｄ／（Ａ×ｒ）からイオン伝導体７０１の厚さ方向のイオン伝導度を算出した。
また、ギャップ電極のネガパターンのマスクをガラス基板に密着させてアルミニウムを電子ビーム蒸着して作製したギャップ電極上に、上記フィルム状のイオン伝導体を密着させ、両電極のイオン伝導体の抵抗値を測定した。測定は、上記測定と同様にミリオームメータからなるインピーダンス測定装置を用い、上記同様に１キロヘルツの測定信号でインピーダンス測定をし、抵抗値ｒを求め、前記イオン伝導体の厚みｄを測定し、式（イオン伝導度σ）＝（ギャップ電極の電極間のギャツプ幅ｗ）／（ギャップ電極の長さＬ×ｄ×ｒ）から前記イオン伝導体のフィルム面方向のイオン伝導度を算出した。このフィルム状のイオン伝導体のイオン伝導度は、厚さ方向がフィルム面方向の９倍（上記加熱工程―冷却工程のサイクル繰り返し処理前）および１３倍（上記加熱工程―冷却工程のサイクル繰り返し処理後）の値であり、異方イオン伝導性をもち、かつ上記加熱工程―冷却工程のサイクル繰り返し処理後では、その異方性が増す結果となった。さらに低温時のイオン伝導性についても測定したところ比較例に比べて良好であり、上記加熱工程―冷却工程のサイクル繰り返し処理後では、前記イオン伝導体の厚さ方向のイオン伝導度は増加した。この結果は下記表１に示した。
【００８６】
（５）架橋構造および未反応モノマーの確認：
得られたイオン伝導体を赤外吸収スペクトル装置、核磁気共鳴スペクトル装置及びマススペクトル装置で分析したところ、モノマー類が調製時の比率で重合して形成された架橋構造になっていると予想される結果となった。確認のために、得られたイオン伝導体を３００℃まで徐々に加熱したところ、酸化しただけで溶融現象は見られず、高分子骨格が化学的に結合された架橋構造を形成していることを確認した。また、得られたイオン伝導体中の未反応モノマーの割合を分析するため、該イオン伝導体をテトラヒドロフラン溶液に１日浸漬した後このテトラヒドロフラン溶液をゲルパーミエーションクロマトグラフィー（ＧＰＣ）で分析したところ、未反応モノマーや低分子量の重合反応物等は観察されず、全てのモノマーが高分子骨格中に化学的に結合されていると考えられる結果となった。
【００８７】
【実施例２】
イオン伝導体を形成するときの重合温度及び作製したイオン伝導体の加熱工程―冷却工程のサイクル繰り返し処理での冷却工程の温度を０℃にしたこと以外は実施例１と同様に行った。
【００８８】
【実施例３】
作製したイオン伝導体の加熱工程―冷却工程のサイクル繰り返し処理での冷却工程の温度を１５℃にしたこと以外は実施例１と同様に行った。
【００８９】
【実施例４】
作製したイオン伝導体に対しての加熱工程―冷却工程のサイクル繰り返し回数を２回にしたこと以外は実施例１と同様に行った。
【００９０】
【実施例５】
作製したイオン伝導体に対して加熱工程―冷却工程のサイクル繰り返し処理を行わなかったこと以外は実施例１と同様に行った。
【００９１】
【実施例６】
実施例１で使用したポリマー前駆体（Ｌ１）の替わりに、以下に示すポリマー前駆体（Ｌ２）を用いたこと以外は実施例１と同様に行った。
ポリマー前駆体（Ｌ２）：
ポリマー前駆体（Ｌ１）の第１のモノマー替わりにアルキル基とポリエーテル基を有するモノマーを用いた。組成は第１のモノマーとして炭素数が１８であるアルキル基を有するｎ−オクタデシルポリエチレングリコール（エチレンオキサイド数＝３０）アクリレートを１５４部、第２のモノマーのポリエチレングリコール（エチレンオキサイド数＝３）メチルメタクリレート１０部、メトキシトリプロピレングリコーアクリレート１０部、架橋剤としてポリエチレングリコールテトラメチレングリコールジメタクリレート１９部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン１部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液２４３０部を添加し、ポリマー前駆体（Ｌ２）を得た。なお第１のモノマーが配向性を示す温度は４６℃であった。
【００９２】
【実施例７】
実施例１におけるポリマー前駆体（Ｌ１）の第１のモノマーとして以下に示すエチレンオキサイド数およびプロピレンオキサイド数が異なるものを使用したこと以外は、実施例１と同様に行った。
第１のモノマー：
メトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝２０）に替わり、エチレンオキサイド数＝１１、プロピレンオキサイド数＝２７であるモノマー、メトキシ−ヘニデカエチレンオキシ−ｂｌｏｃｋ−ヘプタアイコサプロピレンオキシ−アクリレートを使用した。なお第１のモノマーが配向性を示す温度は２５℃であった。
【００９３】
実施例２乃至７において得られたイオン伝導体を実施例１と同様にして、偏光顕微鏡、粘弾性測定装置（ＤＭＳ）とＸ線小角散乱測定装置で配向性の測定を行った。その結果、得られたイオン伝導体は高分子鎖の主鎖部がフィルム面に平行に側鎖部が厚さ方向に配向していると考えられる結果となり、加熱工程―冷却工程のサイクル繰り返し処理の前後で実施例２、４、６及び７では、この配向性が増し、実施例３及び５では変化しないことが分かった。さらに、実施例１と同様にして、前記イオン伝導体のイオン伝導度を測定したところ、異方イオン伝導性を持つ結果となった。実施例１での加熱工程―冷却工程のサイクル繰り返し処理前後の結果と比較すると、実施例２、４、６及び７では、加熱工程―冷却工程のサイクル繰り返し処理前後で異方伝導性が増し、実施例３及び５では変化しないことが分かった。さらに低温時のイオン伝導性についても測定したところ、比較例に比べて良好であった。これらの結果は下記表１に示した。
【００９４】
【比較例１】
イオン伝導体を形成するときの重合温度を２５℃にしたこと以外は実施例１と同様に行った。
【００９５】
【比較例２】
イオン伝導体を形成するときの重合温度が２５℃にし、作製したイオン伝導体に対して加熱工程―冷却工程のサイクル繰り返し処理を行わなかったこと以外は実施例１と同様に行った。
【００９６】
比較例１及び２で得られたイオン伝導体を実施例１と同様にして、偏光顕微鏡、粘弾性測定装置（ＤＭＳ）とＸ線小角散乱測定装置で配向性の測定を行ったところ、得られたイオン伝導体は高分子鎖の主鎖部がフィルム面に平行に側鎖部が厚さ方向に配向していると考えられる結果となったが、いずれも実施例１の方が配向性が高かった。比較例１のイオン伝導体の加熱工程―冷却工程のサイクル繰り返し処理後と、比較例２で得られたものを比較すると、比較例１のほうがやや配向性が高かった。さらに、実施例１と同様にして、前記イオン伝導体のイオン伝導度を測定したところ、異方イオン伝導性を持つ結果となったが、いずれも実施例１の方が異方イオン伝導性が高かった。比較例１のイオン伝導体の加熱工程―冷却工程のサイクル繰り返し処理後後と、比較例２で得られたものを比較すると、比較例１のほうがやや異方イオン伝導性が高かった。
【００９７】
【比較例３】
実施例１におけるポリマー前駆体（Ｌ１）の替わりに以下に示すポリマー前駆体（Ｌ３）を使用したこと以外は、実施例１と同様に行った。
ポリマー前駆体（Ｌ３）：
モノマーとしてアクリル酸６．１部、架橋剤としてポリ（エチレングリコールテトラメチレングリコールジメタクリレート１．８部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン０．０２５部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液１５０．６部を添加して調製した。
第１のモノマーであるアクリル酸が配向性を示す温度を測定した。示差熱分析（ＤＳＣ）によって測定される融点は１３℃付近であったが、−２０〜２０℃の範囲で温度変化させて配向性をクロスニコル偏光下において観察すると、いずれの温度においても暗視野のままであり、配向性を示すことはなかった。
比較例３で得られたイオン伝導体を実施例１と同様にして、偏光顕微鏡、粘弾性測定装置（ＤＭＳ）とＸ線小角散乱測定装置で配向性の測定を行ったところ、得られたイオン伝導体は加熱工程―冷却工程のサイクル繰り返し処理前後とも高分子鎖の主鎖部および側鎖部ともに配向性を持たないと考えられる結果となった。さらに、実施例１と同様にして、このイオン伝導体のイオン伝導度を測定したところ、イオン伝導度に異方性はなかった。
【００９８】
【表１】

【００９９】
【実施例８】
本実施例では、図５に示す構成のシート型二次電池を作製した
即ち、先ず、負極と正極を作製し、得られた負極と正極の両面にイオン伝導体を形成した後、そのイオン伝導体の表面にポリマー前駆体を塗付し支持体の多孔質フィルムの両面に負極と正極を対向させ貼り合わせた後、ポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した後ポリマー前駆体を重合させた。さらに、加熱した後冷却するという処理を何度か繰り返し前記シート型二次電池を作製した。この二次電池の作製手順を図５を参照して以下に説明する。
１．負極４０４の作製
アルゴンガス気流中２０００℃で熱処理した天然黒鉛の微粉末９０部にポリフッ化ビニリデン粉１０部を混合した後、Ｎ−メチル−２−ピロリドン１００部を添加してペーストを調整した。得られたペーストを、銅箔からなる集電体４０２に塗布し、１５０℃で減圧乾燥した。次いで、所定のサイズに切断し、ニッケル線のリードをスポット溶接で集電体４０２に接続し、負極４０４を得た。
２．正極４０７の作製
コバルト酸リチウム粉末９０部に、アセチレンブラック５部、ポリフッ化ビニリデン５部を混合した後、Ｎ−メチル−２−ピロリドン１００部を添加してペーストを調整した。得られたペーストを、アルミニウム箔である集電体４０６に塗布して乾燥した後、ロールプレス機で正極活物質層をプレスした。さらに、アルミニウムのリードを超音波溶接機で接続し、１５０℃で減圧乾燥して正極４０７を得た。
【０１００】
３．電極表面へのイオン伝導体の形成
（１）まず、第１のモノマーであるポリエーテル基を側鎖に有するモノマー：メトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝２０）が配向性を示す温度を測定した。示差熱分析（ＤＳＣ）によって測定されるモノマーの融点は１２℃付近であった（図３）。温度変化させてこのモノマーの配向性をクロスニコル偏光下において観察すると、１２℃以下の場合暗視野から明視野への変化が観察された。したがってこのモノマーの場合、配向性を示す温度は１２℃であった。以下のすべての操作はアルゴンガス雰囲気下で行った。第１のモノマーを１５０部、第２のモノマーとしてメトキシトリプロピレングリコーアクリレート１０部、架橋剤としてポリ（エチレングリコールテトラメチレングリコールジメタクリレート１．８部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン１部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液３０７０部を添加し、ポリマー前駆体（Ｌ１）を得た。
【０１０１】
得られたポリマー前駆体（Ｌ１）を上記１で得られた負極４０４の活物質側とフッ素樹脂層を片面に形成した石英板の樹脂層側とが対向するようにテフロン（登録商標）製のスペーサー（厚さ１０μｍ）を介して形成したセル（図４の重合容器３０１）内に挿入した。重合容器を−２０℃に設定した恒温槽に入れモノマーを配向させた後、１０ｍＷ／ｃｍ^２の紫外線を１時間照射して重合反応と架橋反応を起こした後、前記恒温槽の温度を２５℃にした。その後、前記恒温槽の温度を毎分１℃の割合で上昇させ、４０℃になったらその温度で１０分間保温する加熱工程を行い、次いで前記恒温槽の温度を毎分１℃の割合で下降させ、−２０℃になったらその温度で１０分間保温する冷却工程を行うサイクルを１サイクルとして、このサイクルを５回繰り返した後、前記恒温槽の温度を２５℃にした。かくして、負極４０４上にイオン伝導体を形成した。
以上述べたのと同じ手法で、上記２で得られた正極４０７上にもイオン伝導体を形成した。
【０１０２】
４．二次電池の組み立て
二次電池の組み立て操作はアルゴンガス雰囲気下で行った。
ポリマー前駆体（Ｌ１）の光重合開始剤２、２―ジメトキシ―２―フェニルアセトフェノン１部の替わりに熱重合開始剤であるアゾビスイソブチロニトリル１部を使用してポリマー前駆体（Ｈ１）を調製した。上記３でイオン伝導体を形成した負極４０４と正極４０７のイオン伝導体表面に前記ポリマー前駆体（Ｈ１）を塗付し、負極４０４と正極４０７の表面に形成したイオン伝導体が対向するようにポリエチレンの多孔質フィルムを介して負極４０４と正極４０７を張り合わせ、電極積層体４０９を得た。この電極積層体を１０分間５．３ｋＰａに減圧した後常圧に戻し１０分間維持した。同様の操作（減圧１０分間→常圧１０分間）を２回繰り返した後、電極積層体４０９をポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した。その後、６０℃に加熱して３時間重合反応を行った。ついで、上記３におけると同様にして、電極積層体４０９に対して５回の加熱工程―冷却工程サイクル繰り返し処理を行った後、電極積層体４０９の温度を２５℃にし、図５に示す構成のシート型二次電池を得た。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０３】
【実施例９】
イオン伝導体を形成した負極４０４及び正極４０７及び電極積層体４０９に対する加熱工程―冷却工程サイクル繰り返し処理における冷却工程の温度を変えたこと以外は実施例８と同様にしてシート型二次電池を作製した。
即ち、本実施例では、負極４０４上及び正極４０７上へのイオン伝導体の形成工程での加熱工程―冷却工程サイクル繰り返し処理における冷却工程においては、恒温槽の温度を毎分１℃の割合で下降させ、０℃になったらその温度で１０分間保温した。また、電極積層体４０９に対する加熱工程―冷却工程サイクル繰り返し処理における冷却工程においては、前記電極積層体の温度を毎分１℃の割合で下降させ、１５℃になったらその温度で１０分間保温した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０４】
【実施例１０】
電極積層体４０９に対する加熱工程―冷却工程サイクル繰り返し処理における冷却工程の温度を変えたこと以外は実施例８と同様にしてシート型二次電池を作製した。
即ち、本実施例では、電極積層体４０９に対する加熱工程―冷却工程サイクル繰り返し処理における冷却工程においては、前記電極積層体の温度を毎分１℃の割合で下降させ、１５℃になったらその温度で１０分間保温した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０５】
【実施例１１】
電極積層体４０９の減圧処理（減圧１０分間→常圧１０分間）の回数を１回にしたこと以外は実施例８と同様にしてシート型二次電池を作製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０６】
【実施例１２】
イオン伝導体を形成した負極４０４及び正極４０７及び電極積層体４０９に対して３回の加熱工程―冷却工程サイクル繰り返し処理を行ったこと以外は実施例８と同様にしてシート型二次電池を作製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０７】
【実施例１３】
以下に記載する変更点以外は実施例８と同様にしてシート型二次電池を作製した。
（１）イオン伝導体フィルムの作成：
実施例８の３における同様に、第１のモノマーが配向性を示す温度を測定した後、ポリマー前駆体（Ｌ１）を調製し、このポリマー前駆体（Ｌ１）をポリエチレンの多孔質フィルムに含浸させ、フッ素樹脂層を片面に形成した２枚の石英板を樹脂形成面が対向するようにはさんだ後減圧雰囲気にし、多孔質フィルムと石英板の間に取り込まれた気泡を除去し常圧に戻した後、−２０℃に設定した恒温槽に入れ前記前駆体中のモノマーを配向させた後、１０ｍＷ／ｃｍ^２の紫外線を１時間照射して重合反応と架橋反応を行った後、前記恒温槽の温度を２５℃にした。その後、前記恒温槽の温度を毎分１℃の割合で上昇させ、４０℃になったらその温度で１０分間保温する加熱工程を行い、次いで前記恒温槽の温度を毎分１℃の割合で下降させ、−２０℃になったらその温度で１０分間保温する冷却工程を行うサイクルを１サイクルとして、このサイクルを５回繰り返した後、前記恒温槽の温度を２５℃にし、２枚の石英板を除去しイオン伝導体フィルムを得た。
（２）二次電池の組み立て：
二次電池の組み立て操作はアルゴンガス雰囲気下で行った。
実施例８の３で得られたイオン伝導体を形成した負極４０４と正極４０７のイオン伝導体表面にポリマー前駆体（Ｈ１）を塗付し、負極４０４と正極４０７の表面に形成したイオン伝導体が対向するように上記（１）で得られたイオン伝導体フィルムと負極４０４及び正極４０７を張り合わせ、電極積層体４０９を得た。この電極積層体を１０分間５．３ｋＰａに減圧した後常圧に戻し１０分間維持した。同様の操作（減圧１０分間→常圧１０分間）を２回繰り返した後、ポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した。その後、６０℃に加熱して３時間重合反応を行った。次いで、上記（１）におけると同様にして、電極積層体４０９に対して５回の加熱工程―冷却工程サイクル繰り返し処理を行った後、電極積層体４０９の温度を２５℃にし、シート型二次電池を得た。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０８】
【実施例１４】
実施例８において、ポリマー前駆体（Ｌ１）およびポリマー前駆体（Ｈ１）の第１のモノマーであるポリエーテル基（エチレンオキサイド数、プロピレンオキサイド数＝２０）を側鎖に有するモノマーの替わりにアルキル基（炭素数＝１８）とポリエーテル基（エチレンオキサイド数＝３０）を側鎖に有するモノマーを使用したポリマー前駆体（Ｌ２）およびポリマー前駆体（Ｈ２）を用いたこと以外は実施例８と同様に行った。第１のモノマーが配向性を示す温度は４６℃であった。ポリマー前駆体（Ｌ１）の替わりのポリマー前駆体（Ｌ２）は第１のモノマーとして炭素数が１８であるアルキル基を有するｎ−オクタデシルポリエチレングリコール（エチレンオキサイド数＝３０）アクリレートを１５４部、第２のモノマーのポリエチレングリコール（エチレンオキサイド数＝３）メチルメタクリレート１０部、メトキシトリプロピレングリコーアクリレート１０部、架橋剤としてポリ（エチレングリコールテトラメチレングリコールジメタクリレート１９部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン１部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液２４３０部を添加し、ポリマー前駆体（Ｌ２）を得た。
ポリマー前駆体（Ｈ１）の替わりのポリマー前駆体（Ｈ２）はポリマー前駆体（Ｌ２）の光重合開始剤２、２―ジメトキシ―２―フェニルアセトフェノン１部の替わりに熱重合開始剤であるアゾビスイソブチロニトリル１部を使用してポリマー前駆体（Ｈ１）を調製したものである。
本実施例で得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１０９】
【実施例１５】
本実施例では、負極、正極およびイオン伝導体フィルムの作製を行い、負極と正極の両面にポリマー前駆体を塗付しイオン伝導体フィルムの両面に負極と正極を対向させ貼り合わせた。その後、ポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した後ポリマー前駆体を重合させた。さらに、加熱した後冷却するという処理を何度か繰り返しシート型二次電池を作製した。前記シート型二次電池の作製手順を図５を参照して以下に説明する。
【０１１０】
（１）負極４０４および正極４０７の作製及びこれらの電極上へのイオン伝導体の形成は、実施例８におけると同様にして行った。
（２）イオン伝導体フィルムを実施例１２と同様にして作製した。
（３）二次電池の組み立て
二次電池の組み立て操作はアルゴンガス雰囲気下で行った。
上記（１）で得られたイオン伝導体を形成した負極４０４と正極４０７の活物質表面にポリマー前駆体（Ｈ１）を塗付し、ポリマー前駆体（Ｈ１）の塗付面が対向するように上記（２）で得られたイオン伝導体フィルムと負極４０４及び正極４０７を張り合わせ、電極積層体４０９を得た。この電極積層体を１０分間 で減圧雰囲気下に置いた後常圧に戻し１０分間維持した。同様の操作（減圧１０分間→常圧１０分間）を２回繰り返した後、前記電極積層体をポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した。その後、６０℃に加熱して３時間重合反応を行った。次いで、実施例８の３におけると同様にして、電極積層体４０９に対して５回の加熱工程―冷却工程サイクル繰り返し処理を行った後、電極積層体４０９の温度を２５℃にし、図５に示す構成のシート型二次電池を得た。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１１１】
【実施例１６】
以下に述べる変更点以外は実施例８と同様に行った。
（１）電極表面へのイオン伝導体の形成
実施例８で得たポリマー前駆体（Ｌ１）を実施例８の１で作製した負極４０４の活物質側に塗布した後、フッ素樹脂層を片面に形成した石英板を負極４０４の活物質と対向するよう負極４０４に貼り付けた後、１０分間５．３ｋＰａに減圧した後常圧に戻した。重合容器を−２０℃に設定した恒温槽に入れモノマーを配向させた後、１０ｍＷ／ｃｍ^２の紫外線を１時間照射して重合反応と架橋反応を起こした後、前記恒温槽の温度を２５℃にした。その後、前記恒温槽の温度を毎分１℃の割合で上昇させ、４０℃になったらその温度で１０分間保温する加熱工程を行い、次いで前記恒温槽の温度を毎分１℃の割合で下降させ、−２０℃になったらその温度で１０分間保温する冷却工程を行うサイクルを１サイクルとして、このサイクルを５回繰り返した後、前記恒温槽の温度を２５℃にした。かくして、負極４０４上にイオン伝導体を形成した。
以上述べたのと同じ手法で、実施例８の２で作製した正極４０７上にもイオン伝導体を形成した。
（２）二次電池の組み立て
二次電池の組み立て操作はアルゴンガス雰囲気下で行った。
上記（２）で得られたイオン伝導体を形成した負極４０４と正極４０７のイオン伝導体表面にポリマー前駆体（Ｈ１）を塗付し、負極４０４と正極４０７の表面に形成したイオン伝導体が対向するように実施例１２におけると同様にして作製したイオン伝導体フィルムと負極４０４及び正極４０７を張り合わせ、電極積層体４０９を得た。この電極積層体を１０分間 で減圧雰囲気下に置いた後常圧に戻し１０分間維持した。同様の操作（減圧１０分間→常圧１０分間）を２回繰り返した後、ポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉した。その後、６０℃に加熱して３時間重合反応を行った。次いで、上記（１）におけると同様にして、電極積層体４０９に対して５回の加熱工程―冷却工程サイクル繰り返し処理を行った後、電極積層体４０９の温度を２５℃にし、シート型二次電池を得た。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１１２】
【実施例１７】
イオン伝導体を形成した負極４０４及び正極４０７及び電極積層体４０９に対して加熱工程―冷却工程サイクル繰り返し処理を行わなかったこと以外は実施例８と同様にしてシート型二次電池を作製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１１３】
【実施例１８】
実施例８においてポリマー前駆体（Ｌ１）および（Ｈ１）の第１のモノマーとして使用したポリエーテル基を側鎖に有するモノマーのメトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレート（エチレンオキサイド数、プロピレンオキサイド数＝２０）に替わり、エチレンオキサイド数＝１１およびプロピレンオキサイド数＝２７であるメトキシ−アイコサエチレンオキシ−ｂｌｏｃｋ−アイコサプロピレンオキシ−アクリレートを用いたこと以外は実施例８と同様に行った。なお第１のモノマーが配向性を示す温度は２５℃だった。本実施例で得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価したところ、比較例に比べて高容量でサイクル寿命が良好な結果が得られた。この結果は表２に示した。
【０１１４】
【比較例４】
負極４０４及び正極４０７にイオン伝導体を形成する際、恒温槽の温度を２５℃に保温したこと以外は、実施例８と同様にしてシート型二次電池を作製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価し、その結果は表２に示した。
【０１１５】
【比較例５】
実施例８において、ポリマー前駆体（Ｌ１）及び（Ｈ１）の替わりに、以下に示すポリマー前駆体（Ｌ３）および（Ｈ３）を使用し、重合時の温度を２５℃に保温し、電極積層体４０９対して加熱工程―冷却工程サイクル繰り返し処理を行わなかったこと以外は実施例８と同様にしてシート型二次電池を作製した。
ポリマー前駆体（Ｌ３）：
モノマーとしてアクリル酸６．１部、架橋剤としてポリ（エチレングリコールテトラメチレングリコールジメタクリレート１．８部、光重合開始剤として２、２―ジメトキシ―２―フェニルアセトフェノン０．０２５部を混合し、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液１５０．６部を添加して調製した。第１のモノマーであるアクリル酸が配向性を示す温度を測定した。示差熱分析（ＤＳＣ）によって測定される融点は１３℃付近であったが、−２０〜２０℃の範囲で温度変化させて配向性をクロスニコル偏光下において観察すると、いずれの温度においても暗視野のままであり、配向性を示すことはなかった。
ポリマー前駆体（Ｈ３）：
ポリマー前駆体（Ｌ３）の光重合開始剤２、２―ジメトキシ―２―フェニルアセトフェノン１部の替わりに熱重合開始剤であるアゾビスイソブチロニトリル１部を使用してポリマー前駆体（Ｈ３）を調製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価し、その結果は表２に示した。
【０１１６】
【比較例６】
イオン伝導体の替わりに電解液を使用し、以下の方法でシート形電池を作製し、その後得られた電池の充放電試験を行った。この結果は下記表２に示した。
（１）負極４０４及び正極４０７は実施例８におけると同様にして作製した。
（２）二次電池の組み立て
ポリエチレンの多孔質フィルムの両面に負極４０４と正極４０７を対向させ貼り合わせ、テトラフルオロホウ酸リチウムをエチレンカーボネートおよびγ−ブチルラクトンを３：７の体積比で混合した溶液に溶解させた２モル／ｄｍ^３の電解液を含浸保持させた後、ポリプロピレン／アルミニウム箔／ポリエチレンテレフタレートのラミネートフィルムである防湿性フィルムで密閉して、シート形にじ電池を作製した。
得られた二次電池を、容量試験とサイクル寿命の充放電試験により評価し、その結果は表２に示した。
【０１１７】
【表２】

【０１１８】
【発明の効果】
本発明によれば、イオン伝導体の高分子骨格の配向性をより高めることにより、低コストで簡便な方法で作製できる高イオン伝導性であり機械的強度に優れたイオン伝導体及び高容量でサイクル寿命の良好な性能を持つ二次電池を達成できる。
【図面の簡単な説明】
【図１】本発明のイオン伝導体の高分子構造を模式的に示す図である。
【図２】本発明のイオン伝導体の製造方法の一例のフローチャートを示す。
【図３】本発明において使用する第１のモノマーの融点を示差熱分析（ＤＳＣ）により測定した結果得られ図である。
【図４】本発明のイオン伝導体の製造方法で使用する製造装置の一例の構成を模式的に示す図である。
【図５】単層式シート型二次電池の一例の構成を模式的に示す略断面図である。
【図６】単層式扁平形（コイン形）二次電池の一例の構成を模式的に示す略断面図である。
【図７】実施例１で作製したフィルム状のイオン伝導体の配向性をＸ線小角散乱により測定した結果得られ図である。
【図８】イオン伝導体のイオン伝導性測定装置の模式図である。
【符号の説明】
１０１ 主鎖部
１０２ 側鎖部
１０３ 架橋結合
１０４ イオン伝導経路
１０５ ポリエーテル基
３０１ 重合容器
３０２ 温度調節装置、
３０３ 光エネルギー照射装置
４０１ イオン伝導体
４０２ 負極集電体
４０３ 負極活物質（負極材料）
４０４ 負極
４０５ 正極活物質（正極材料）
４０６ 正極集電体
４０７ 正極
４０８ 外装材
４０９ 電極積層体
５０１ 負極
５０２ イオン伝導体
５０３ 正極
５０４ 負極缶（負極端子）
５０５ 正極缶（正極端子）
５０６ ガスケット[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an ion conductor and a secondary battery. More specifically, the present invention relates to a method for manufacturing an ion conductor having high ion conductivity and high charge / discharge efficiency, and a method for manufacturing a secondary battery using the ion conductor.
[0002]
[Prior art]
Recently, CO contained in the atmosphere₂The amount of gas is increasing, and the greenhouse effect caused by the gas is concerned about global warming.₂Measures to reduce gas emissions are being considered worldwide. For example, in a thermal power plant that converts thermal energy obtained by burning fossil fuel into electric energy, a large amount of CO₂Gas emissions make it difficult to build new thermal power plants. As a result, in order to respond to the growing demand for electricity, as an effective way to use electricity, surplus electricity, nighttime power, is stored in secondary batteries installed in ordinary households and used during the daytime when power consumption is high. So-called load leveling has been proposed. Separately, cars running on fossil fuels are CO₂NO other than gas_x, SOx, hydrocarbons, etc., are regarded as a problem as other sources of air pollutants. From the perspective of reducing the sources of air pollutants, electric vehicles that run by driving a motor with electricity stored in a secondary battery do not emit air pollutants, so they are attracting attention and are being researched and developed for early commercialization. Is being actively conducted. Secondary batteries used for such load leveling applications and electric vehicles are required to have a high energy density, a long life, and a low cost.
Further, as for a secondary battery used for a power source of a portable device such as a book-type personal computer, a word processor, a video camera, and a mobile phone, there is a strong demand for early provision of a small, lightweight, and high-performance secondary battery. .
[0003]
As a high-performance secondary battery capable of meeting the above-mentioned requirements, a secondary battery using a lithium-graphite intercalation compound as a negative electrode has been reported in "JOURNAL OF THE ELECTROCHEMICAL SOCIETY" 117, 222 (1970). A rocking chair-type secondary battery, in which lithium (including graphite) is used as the negative electrode active material and lithium ions introduced into the intercalation compound are used as the positive electrode active material, and lithium is inserted and stored between the carbon layers by a charging reaction, so-called “lithium”. The development of "ion batteries" has progressed, and some have been put into practical use. In this lithium ion battery, carbon is used as a negative electrode, which is a host material that uses lithium as a guest and intercalates between layers, to suppress dendrite growth of lithium during charging and achieve long life in a charge / discharge cycle.
However, in a secondary battery using a battery reaction (charge-discharge reaction) by lithium ions, such as the above-mentioned lithium ion secondary battery, the organic solvent is used as a solvent for the electrolytic solution. As a result, carbon dioxide, hydrocarbons, and the like are generated, and the solvent does not return to the original solvent due to the recombination reaction. Therefore, the electrolyte may be deteriorated and the internal impedance of the secondary battery may increase. Further, when overcharged, an internal short circuit occurs in the battery, and heat is generated, and a rapid decomposition reaction of the solvent proceeds, sometimes leading to a decrease in the performance of the secondary battery.
[0004]
In order to solve the problems related to the decomposition and deterioration of the electrolyte in the secondary battery using the charge / discharge reaction by lithium ions, US Pat. No. 5,609,974 discloses diacrylate, monoacrylate, and carbonate. An ionic conductor obtained by copolymerizing three types of acrylate-based monomers containing a group in the presence of an organic solvent and a supporting electrolyte has been proposed. In order to prevent electrolyte leakage, JP-A-5-25353 discloses an ionic conductor using a polymer skeleton obtained by copolymerizing three types of monomers of diacrylate, monoacrylate and vinylene carbonate. Has been proposed. These ion conductors have a problem that the ion density is reduced when they are used in a secondary battery because the ion conductivity is lower than 1/4 or less as compared with a liquid electrolyte. Further investigations by the present inventors have revealed that the above proposal does not provide a battery having the necessary strength at the time of production and use of a secondary battery, and has a large decrease in ionic conductivity at low temperature compared to normal temperature, resulting in an increase in energy density. It was found that there was a problem of a rapid decrease.
[0005]
Japanese Patent Publication No. 7-95403 proposes a two-dimensionally cross-linked ion conductor using lipids, and Japanese Patent Application Laid-Open No. 7-224105 discloses a method of using a surfactant to form a hydrophilic polymer phase and a hydrophobic polymer. An ionic conductor having a bicontinuous structure in which a conductive polymer phase is continuous has been proposed. However, these proposals have a problem that it is difficult to completely remove lipids and surfactants in the washing step, and the remaining lipids and surfactants deteriorate the cycle life. Furthermore, since it contains lipids and surfactants that do not bind to the polymer skeleton, the mechanical strength required when processing the resulting ionic conductor is weak, and the lipids and surfactants are removed in the washing step As a result, there is also a problem that an empty wall is generated and the strength is further deteriorated.
[0006]
As a method for improving the mechanical strength of the ionic conductor, Japanese Patent Application Laid-Open No. 5-299119 proposes an ionic conductor comprising a high-polarity polymer phase and a low-polarity polymer phase. However, this ionic conductor has a problem that the ionic conductivity is low because the low-polarity polymer phase of the support phase does not function as the ionic conductive phase. Further, Japanese Patent No. 3045120 proposes an ionic conductor using an alkylene oxide derivative having a substituent composed of a liquid crystalline compound, and JP-A-5-303905 discloses a method of using a monomer containing a polyether group. Cured ionic conductors have been proposed. However, these ion conductors have a problem that the ion diffusivity is low and the ion conductivity is still low because the polymer skeleton structure is irregular.
[0007]
The present inventors have proposed a secondary battery in which ion channels are oriented in order to improve cycle life in Japanese Patent Application Laid-Open No. H11-345629, and in Japanese Patent Application No. 2000-388370, have disclosed a high battery that is a component of an ion conductor. By containing at least a polyether group and an alkyl group having 6 or more carbon atoms in the side chain of the molecule, the polymer backbone is oriented to provide an ion conductor having high ionic conductivity and excellent mechanical strength, and a long cycle life and a high capacity. A novel secondary battery and its manufacturing method were proposed.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems in the related art. An object of the present invention is to further enhance the orientation of the polymer skeleton, thereby providing an ionic conductor having high ionic conductivity and excellent mechanical strength, which can be manufactured at a low cost by a simple method, and a cycle life with high capacity. Another object of the present invention is to provide a method for manufacturing a secondary battery having good performance.
[0009]
[Means for Solving the Problems]
The method for producing an ionic conductor of the present invention is a method for producing an ionic conductor having anisotropic ionic conductivity mainly composed of at least one kind of polymer compound and at least one kind of electrolyte. A step of forming the ion conductor by a polymerization reaction of a polymer precursor containing a monomer and at least one type of electrolyte, wherein during the polymerization reaction, the polymer precursor, the monomer in the precursor is oriented It is characterized in that it is kept at a temperature lower than the temperature showing the property.
[0010]
In the present invention, the `` temperature at which the monomer exhibits orientation '' is a temperature at which a change from dark field to bright field or from bright field to dark field is observed under crossed Nicols polarization, and is near the melting point. There are many. Therefore, in the measurement of the temperature indicating the orientation, the melting point of the monomer was first measured by differential thermal analysis (DSC), and then the temperature was changed near this temperature to specify the temperature indicating the orientation under crossed Nicols polarization.
[0011]
The step of forming the ion conductor by a polymerization reaction of the polymer precursor, after applying the polymer precursor on a substrate having planarity, the polymer precursor applied on the substrate, It is preferable to perform the polymerization by irradiating the polymer precursor with an energy ray while maintaining the temperature at or below the temperature at which the monomer exhibits orientation. Irradiation of the energy beam in this case, the energy beam transmitting member disposed so as to keep a constant distance to the substrate on which the polymer precursor is applied and to cover the surface of the applied polymer precursor. It is preferably carried out via The energy ray transmitting member may be made of, for example, quartz. The substrate may be a positive electrode in which a positive electrode material is provided on a positive electrode current collector or a negative electrode in which a negative electrode material is provided on a negative electrode current collector. Further, a step (a) of heating the formed ion conductor to a temperature at which the monomer exhibits orientation is performed, and then a step of cooling the ion conductor to a temperature at which the monomer exhibits orientation ( It is preferable to apply a process of repeating the cycle of (b) one or more times.
[0012]
The method for manufacturing a secondary battery of the present invention typically includes the following two embodiments, that is, a first embodiment and a second embodiment.
[0013]
(First embodiment)
A method for manufacturing a secondary battery having a configuration in which an ionic conductor is disposed between a positive electrode and a negative electrode provided to face each other,
(1) applying a first polymer precursor containing at least one type of monomer and at least one type of electrolyte to the surface of the positive electrode or / and the negative electrode;
(2) By subjecting the first polymer precursor applied to the surface of the positive electrode and / or the negative electrode to a polymerization reaction while keeping the temperature of the monomer in the precursor below the temperature at which the monomer exhibits orientation. Forming a first ion conductor having anisotropy in ion conductivity,
(3) applying a second polymer precursor containing at least one type of monomer and at least one type of electrolyte to the surface of the ion conductor;
(4) laminating the positive electrode and the negative electrode such that the first ion conductor having the applied second polymer precursor is located between the positive electrode and the negative electrode; and
(5) keeping the second polymer precursor located between the bonded positive electrode and negative electrode via a first ion conductor at a temperature equal to or lower than the temperature at which the monomer in the precursor exhibits orientation. The second ion conductor is formed by being subjected to a polymerization reaction while the interface between the first ion conductor formed on the surface of the positive electrode or the negative electrode and the first ion conductor is not formed. A step of bringing the interface of the negative electrode or the positive electrode or the interface of the first ion conductor formed on the surface of the negative electrode or the positive electrode into contact with the second ion conductor formed later with adhesiveness , (1) to (5) are sequentially performed.
[0014]
(Second aspect)
A method for manufacturing a secondary battery having a configuration in which an ionic conductor is disposed between a positive electrode and a negative electrode provided to face each other,
(1) subjecting a first polymer precursor containing at least one kind of monomer and at least one kind of electrolyte to a polymerization reaction while maintaining the temperature of the first polymer precursor in the precursor at a temperature equal to or lower than a temperature at which the monomer exhibits orientation. Forming a first ion conductor having anisotropy in ion conductivity by
(2) A second polymer precursor containing at least one monomer and at least one electrolyte is coated on both surfaces of the first ion conductor or at least one surface of the positive electrode and / or the negative electrode. Attaching process,
(3) laminating the first ion conductor so as to be located between the positive electrode and the negative electrode; and
(4) a second polymer having an anisotropy in ionic conductivity by subjecting the second polymer precursor to a polymerization reaction while keeping it at a temperature not higher than the temperature at which the monomer in the precursor exhibits orientation; An ionic conductor is formed, and the interface between the positive electrode and the first ionic conductor and the interface between the negative electrode and the first ionic conductor are in contact with the second ionic conductor formed later with adhesion. Steps (1) to (4) are sequentially performed. In the step (1), it is preferable that the first polymer precursor is applied to both surfaces of a predetermined substrate, and the applied polymer precursor is subjected to a polymerization reaction as described above.
[0015]
In the method for producing a secondary battery according to the first aspect and the second aspect, the step of forming the ionic conductor includes the step of forming the coated polymer precursor such that the monomer in the precursor is oriented. It is preferable to perform the polymerization reaction by irradiating the polymer precursor with an energy ray while maintaining the temperature at or below the temperature indicating the following. In this case, the irradiation with the energy beam is performed by keeping the distance to the substrate on which the polymer precursor is applied constant and covering the surface of the applied polymer precursor with an energy ray transmitting member. It is preferably carried out via The energy ray transmitting member may be made of, for example, quartz. Further, a step (a) of heating the formed ion conductor to a temperature at which the monomer exhibits orientation is performed, and then a step of cooling the ion conductor to a temperature at which the monomer exhibits orientation ( It is preferable to perform a process of repeating the cycle of (b) one or more times.
[0016]
The ionic conductor in the present invention may be composed of a polymer chain containing at least a segment represented by the following general formula (1).
Embedded image
General formula (1)

(Wherein, R1 and R2 are each a hydrogen atom or an alkyl group having 2 or less carbon atoms, A and B are each a group containing at least a polyether, and R3 has at least an alkyl group having 1 to 4 carbon atoms. Group.)
[0017]
Either A or B in the general formula (1) is-(CH₂―CH₂-O)_m-And the other is-(CH₂―CH₂(CH₃) -O)_n-(M and n are preferably integers of 1 to 30). More preferably, m and n are m / n = 0.5-2.
[0018]
Further, the ionic conductor in the present invention may be composed of a polymer chain containing at least a segment represented by the following general formula (2).
Embedded image
General formula (2)

(Wherein R4 and R5 are each a hydrogen atom or an alkyl group having 2 or less carbon atoms, and X is-(CH₂―CH₂-O)_k-(K is an integer of 1 to 40), and R6 is a linear alkyl group having at least 6 to 22 carbon atoms or an alkylbenzyl group having a linear alkyl group having 6 to 22 carbon atoms. It is. )
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a method for producing the ionic conductor of the present invention will be described.
The present invention, in order to produce an ionic conductor having anisotropic ionic conductivity mainly composed of at least one polymer compound and at least one electrolyte, at least one monomer and at least one kind of The polymer precursor containing the electrolyte was subjected to a polymerization reaction while keeping the temperature at or below the temperature at which the monomer in the precursor showed orientation. As a result, an ion conductor made of a polymer having a polymer chain having a main chain part and a side chain part having an orientation and a crosslinked structure was able to be produced. And it turned out that this ion conductor is excellent in mechanical strength. Further, the lithium secondary battery manufactured using this ionic conductor had a high capacity, a high charge / discharge efficiency and a long life. The present invention is based on these findings.
[0020]
The reason that the ionic conductor having excellent characteristics can be manufactured by the above-described method is considered as follows. That is, when polymerization is performed in a state containing a monomer having a side chain having orientation, the main chain itself has orientation by forming a state in which the side chain is oriented, and the entire polymer has an orientation structure. It is considered that by forming and maintaining the temperature at the time of polymerization below the temperature at which the monomer is oriented, the resulting polymer has a structure with higher orientation. Since the molecular motion of the produced polymer is lower than that of the monomer, the oriented structure is maintained even when the temperature becomes higher than the temperature at which the monomer is oriented. When such a polymer holds the electrolyte, ion diffusion is regulated in the orientation direction of the polymer. When considering the speed of movement of the electrolyte between two points in the polymer holding the electrolyte, the polymer is more ordered because of its oriented structure than in a disordered state, and the polymer is oriented in the direction of a straight line connecting the two points. If it has directionality, it is considered that the latter has a shorter moving distance, and if the number of ions and the mobility of ions in a certain space are the same, the latter has a higher moving speed. For this reason, the ion conductivity is improved in the direction along the direction in which the molecules are arranged as compared with the other directions. In other words, anisotropy occurs in the ion conductivity.
[0021]
FIG. 1 is a diagram schematically showing a polymer structure of the ion conductor of the present invention. As shown in FIG. 1A, the side chains 102 and the main chains (parts) 101 of the polymer chains constituting the polymer compound are respectively oriented, whereby a regular polymer chain skeleton structure can be formed. In addition, since the polymer chains constituting the ion conductor of the present invention form the crosslinks 103, a strong skeleton structure having three-dimensional regularity can be formed, and an ion having excellent mechanical strength can be formed. It is believed that a conductor is obtained. At this time, as shown in FIG. 1, the side chains containing the polyether groups are oriented in a certain direction, so that the electrolyte having an affinity for the polyether groups can easily move in the orientation direction of the polyether groups. That is, the ion conduction path 104 as shown in FIG. 1A is formed in a certain direction. It is considered that the ions are more likely to move in the direction of the ion conduction path than in the case of FIG. 1B in which the polyether groups are randomly present without orientation and the ion conductivity is improved.
[0022]
As described above, in the method for producing an ion conductor of the present invention, a polymer precursor obtained by mixing a predetermined monomer and a predetermined electrolyte is kept at a temperature equal to or lower than the temperature at which the monomer exhibits orientation. It is characterized by polymerization. Hereinafter, preferred embodiments of the method for producing an ion conductor of the present invention will be described in detail with reference to FIGS.
FIG. 2 shows a flowchart of an example of the method for producing an ion conductor of the present invention, and FIG. 4 shows a preferred example of a production apparatus used in the method of producing an ion conductor of the present invention. . In FIG. 4, 301 indicates a polymerization vessel, 302 indicates a temperature control device, and 303 indicates a light energy irradiation device.
[0023]
Referring to FIG. 2, a method for manufacturing an ion conductor of the present invention will be described.
A first monomer having a polyether group-containing side chain according to the general formula (1), a solvent, and an electrolyte are mixed. If necessary, a second monomer having at least one type of polar group selected from the group consisting of a polyether group, a cyano group, an amino group, an amide group and a carbonate group in a side chain, and a third monomer capable of forming a crosslinked structure Is added. A polymerization initiator is added to the mixture and stirred well until a homogeneous mixture is obtained (Step A). Next, this mixture (304) is inserted into the polymerization vessel 301 shown in FIG. 4 (Step B), and while keeping the temperature below the temperature at which the monomer shows the orientation by the temperature control device 302 shown in FIG. The polymerization reaction is performed by irradiating the inside of the container (step C). The polymerization vessel 301 is returned to room temperature, and the polymerization product is taken out of the vessel to obtain an ion conductor (step D).
The temperature at which the polymerization is carried out is desirably 0 to 100 ° C. lower than the temperature at which the monomer exhibits orientation. More preferably, the temperature is 5 to 70 ° C. lower than the temperature at which the monomer exhibits orientation.
[0024]
As for the amount of each monomer to be added, first, the mixing ratio of the first monomer and the second monomer is such that the number of moles of the first monomer / the number of moles of the second monomer = 0.01 to 1, preferably 0.1 to 0.1. Mixing so as to be 02 to 0.5 is desirable because the affinity between the polymer compound and the solvent becomes good. Further, the addition amount of the third monomer is (mol number of the first monomer + mol number of the second monomer) / mol number of the third monomer = 0.1 to 30, preferably 1 to 10. It is desirable to mix as much as possible because the ion conduction path is formed stably and the mechanical strength is good. The amount of the solvent to be added is preferably from 0 to 20 and more preferably from 1 to 15 based on the total weight of the monomers.
[0025]
When performing the polymerization reaction (step C), it is preferable to perform the polymerization in a closed system, except for the case where gas is generated by the polymerization reaction, because the change in the composition ratio accompanying the evaporation of the solvent and the monomer is preferable. It is also preferable to carry out the polymerization while stirring such as ultrasonic dispersion if necessary so that the system is not separated by the precipitation of the material monomer. Further, when performing the polymerization reaction, in order to improve the orientation of the polymer skeleton, a method of performing polymerization in a state where a magnetic field or an electric field is applied, or by contacting a substrate which has been subjected to a surface treatment such as rubbing treatment or hydrophobic treatment, to carry out polymerization. A method is preferable, and it is more preferable to carry out polymerization by bringing the mixture into contact with a substrate having hydrophobicity, since an ion conduction path is easily formed stably. The substrate having hydrophobicity is preferably a substrate having a contact angle of water of 20 degrees or more, more preferably a substrate having a contact angle of 50 degrees or more, and more preferably a substrate having a uniform water contact angle. It is more desirable because an ion conduction path is formed in the fin.
[0026]
As the substrate, a substrate having a shape such as a granular shape, a plate shape, and a cylindrical shape can be used, but it is preferable to use a plate-shaped substrate because the direction of the ion conduction path can be easily and stably controlled uniformly. For example, as a substrate having such hydrophobicity, a substrate of a fluororesin such as tetrafluoroethylene, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, or a hydrophobic resin such as polyethylene / polypropylene resin, glass, Fluoroplastic film such as tetrafluoroethylene, polyvinylidene fluoride, copolymer of vinylidene fluoride and hexafluoropropylene, polyethylene film, polypropylene film, etc. on a substrate such as metal, substrate such as glass or metal Substrate coated with fluororesin such as tetrafluoroethylene, polyvinylidene fluoride, copolymer of vinylidene fluoride and hexafluoropropylene, polyethylene resin, or polypropylene resin, or hydroxyl group of glass substrate chemically with silylating agent In the case where the ion conductor of the present invention is provided between the negative electrode and the positive electrode of the secondary battery, a fluorocarbon resin such as a copolymer of vinylidene fluoride and hexafluoropropylene, Substrates such as an electrode structure manufactured by containing a polyethylene resin or a polypropylene resin are exemplified.
[0027]
As a method of contacting a substrate having hydrophobicity, it is desirable to use a polymerization vessel in which at least one surface is formed of a substrate having hydrophobicity. In the case of producing a film-like polymer, it is preferable to polymerize the widest surface of the obtained film in contact with the substrate, since an ion conduction path is easily formed in the thickness direction of the film. More preferably, the polymerization is carried out in a state where both surfaces of the wide surface are in contact with the substrate.
[0028]
As the polymerization reaction, a polymerization method suitable for the monomer to be used is used. However, polymerization using ultraviolet rays is preferable because the polymerization reaction can be performed while keeping the temperature at an arbitrary temperature. In the case of a polymerization reaction of a polymer precursor inserted between the electrode laminates, a polymerization reaction using thermal energy is suitable. Further, it is more preferable that this polymerization reaction is a radical polymerization reaction because the polymerization can be performed under mild conditions.
[0029]
It is preferable to perform a step of forming a crosslinked structure in addition to the step of performing a polymerization reaction because the ion conduction path of the ion conductor becomes more stable and the mechanical strength is further improved. Examples of the step of forming the crosslinked structure include a method of forming a crosslinked structure after the polymerization reaction and a method of forming a crosslinked structure simultaneously with the polymerization reaction. As a method of forming a crosslinked structure after the polymerization reaction, a method that can be used with a monomer capable of forming a crosslinked structure is used. For example, a radical generator is added to a polymer, ultraviolet rays, an electron beam, a gamma ray, a heat ray, a plasma, etc. Irradiation to generate a radical to cause a cross-linking reaction, and a method in which a part of the active group of the polymer chain is reacted with a cross-linking agent to cause a cross-linking reaction. The method for forming a crosslinked structure simultaneously with the polymerization reaction is a method in which the above polymerization reaction is used as it is. However, a third monomer which forms a crosslinked structure by the polymerization reaction is added to a mixture of the monomers to be used. This is preferable because the ion conduction path of the ion conductor is more stably and uniformly formed.
[0030]
A cycle in which the step (a) of heating the ion conductor obtained as described above to a temperature at which the monomer exhibits the orientation and then a step (b) of cooling the monomer to a temperature at which the monomer exhibits the orientation are performed. Is repeated one or more times to improve the orientation of the polymer skeleton of the ion conductor. At this time, the ionic conductor is kept at a constant temperature during the heating of the ionic conductor in the step (a), and the temperature is preferably 10 to 200 ° C. higher than the temperature at which the monomer exhibits orientation, preferably 15 to 100 ° C. It is more preferable that the temperature is higher by ° C.
Further, the ion conductor is kept at a constant temperature during cooling of the ion conductor in the step (b), and the temperature is preferably 0 to 100 ° C. lower than the temperature at which the monomer exhibits orientation, and 5 to 50 ° C. Lower is more preferred. When heating or cooling the ionic conductor in the steps (a) and (b), the ionic conductor is kept at a constant temperature as described above. The holding time is preferably from 5 to 120 minutes, and from 10 to 60 minutes. More preferred.
[0031]
Further, the orientation of the polymer skeleton of the ion conductor can be improved by a method of applying a magnetic field or an electric field, a method of performing a stretching treatment, or the like.
[0032]
In general, a method of producing an ion conductor by polymerization according to a shape to be used is adopted. Separately, a method of cutting the obtained ion conductor into a predetermined shape and using the same, A method in which the body is pulverized and processed into a powder form, then molded into a predetermined shape together with a binder and used may be employed.
[0033]
Further, in addition to the above-described steps, a step of incorporating a support into the ion conductor may be provided. In this case, the method of incorporating the support includes a method in which, when the mixed solution is inserted into the polymerization vessel (Step B), the support is also placed in the polymerization vessel and the entire support is polymerized, and an ion conductor or a polymer compound is used. And a method in which a support is mixed with a material obtained by pulverizing the powder and the support is supported. As the support, a resin powder, a glass powder, a ceramic powder, a nonwoven fabric, a porous film, or the like can be used. When the content of these supports is controlled to preferably 1 to 50% by weight, more preferably 1 to 40% by weight of the entire ionic conductor, the mechanical strength of the entire ionic conductor is improved and It is desirable because the ionic conduction path that passes through the interface of the body itself is appropriately formed, and the volume occupied by the ionic conductor itself is less likely to decrease. Further, in order to improve the affinity and adhesion between the support and the ion conductor itself, the support may be subjected to surface treatment by corona discharge or plasma treatment.
[0034]
As a method of observing the presence or absence and orientation direction of the obtained ionic conductor, for example, a method of directly observing with a polarizing microscope, an X-ray diffraction measuring device, an X-ray small angle scattering measuring device or an electron microscope, infrared absorption A spectroscopic device, a nuclear magnetic resonance spectrometer or a thermal analysis measuring device for measuring a specific crystal structure in the ion conductor, and a method for observing in combination with the above method or a method for observing a change before and after stretching in combination with the stretching step , And the like.
Examples of the method of observing with the polarizing microscope include a method of observing optical anisotropy from a change in brightness of a sample under crossed Nicols polarization, measuring presence or absence of an orientation and an orientation direction, and further measuring a variation in an orientation state. Can be
[0035]
As a method of observing the orientation with the X-ray diffraction measuring device or the X-ray small angle scattering measuring device, a method of measuring from a diffraction or scattering pattern obtained by irradiating a sample with X-rays, that is, a point beam X-ray When a sample is irradiated with a sample, the sample has an orientation if a spot-shaped Laue pattern is formed, approaches a ring pattern when the orientation decreases, and is measured because the orientation is completely lost when the ring pattern is complete. Method.
At this time, the orientation direction can be measured from the spot-shaped Laue pattern. Another method is to irradiate X-rays in the form of a line beam from different directions on the sample and measure the diffraction or scattering peaks of the microcrystals to determine the non-orientation, plane orientation, uniaxial orientation, or double orientation of the sample. It is also possible to measure the presence / absence and orientation of the orientation.
[0036]
When it is known that the measurement sample has a microcrystalline phase, when the measurement sample is irradiated with X-rays from all directions including the X, Y, and Z axes and the diffraction or scattering peak is measured, the measurement sample starts from a specific direction. If there is a peak that appears at a specific position only when irradiating, a microcrystalline phase having a plane interval corresponding to the peak position exists only in a direction along the irradiation direction, and the microcrystalline phase is oriented in a specific direction Suggest that you are. For example, if it is known that the measurement sample has a microcrystalline phase, the measurement sample is first put into a powder state, and a peak position corresponding to a plane interval of the microcrystal phase is measured. X-rays are irradiated from all directions including the X, Y, and Z axes, and the irradiation direction at which a peak corresponding to the plane interval of the microcrystalline phase appears is measured. If the direction in which this peak appears when measured by the transmission method (small angle) is only in the X-axis direction of the sample, it means that it is uniaxially oriented in the direction along the X-axis, and only in the direction along the XY plane. When a peak appears in the direction, the surface is oriented in a direction parallel to the XY plane, and when a peak appears only in the X-axis and Y-axis directions, double orientation occurs in the directions along the X-axis and the Y-axis, respectively. If the peaks appear in all directions and the peak intensity ratios are the same, it is completely disordered, that is, it is not oriented.
[0037]
When peaks appear in all directions but appear at different intensity ratios, it is considered that they have orientation but low overall ordering, that is, orientation. When measuring the intensity ratio by changing the irradiation direction, make the shape constant with respect to the irradiation direction, such as a method of measuring the sample in a spherical shape or a method of cutting out and measuring in a fixed shape according to the irradiation direction. Can be accurately determined. Further, when a specific crystal structure of a sample changes due to a temperature change, for example, when a specific plane interval disappears due to a change of a crystal to an amorphous state by heating, a peak change accompanying the temperature change. By measuring, it is possible to observe the orientation of only that specific part of the internal structure.
[0038]
As a method of measuring a specific crystal part of a polymer compound in an ionic conductor, a method of measuring the presence or absence of an absorption band peculiar to the crystal part and an intensity ratio with an infrared absorption spectrum device, and a method of heating and cooling with a nuclear magnetic resonance spectrum device From the accompanying change in the peak shape, that is, from the change in the crystal part having a wide peak width and the non-crystal part having a narrow peak width (the chemical shift of the atomic spin in the crystal part in which the rotation of the atomic bond is restricted is determined by the non-crystallizable non-crystalline part. Phenomenon in which the peaks are split in multiple steps because the amount of shift due to mutual arrangement with adjacent atoms is not averaged as compared to the atoms in the part) The method of measurement, the thermal energy of crystallization and melting by differential thermal analysis with a thermal analyzer And a method of measuring from the relaxation / dispersion temperature of the side chain portion and the main chain portion of the polymer chain and the energy amount thereof in the viscoelasticity measurement. Further, it is also possible to combine the measurement by these methods and the operation of stretching the sample to observe the orientation by a change in peak shape, strength change or thermal energy before and after stretching and in the stretching direction.
[0039]
The term “orientability” in the present invention means the orientation observed by the method described above or the like, and if the orientation is not completely non-oriented, the orientation of the present invention is maintained even if the orientation is weak. Although it can be said that it has, the thing with strong orientation is preferable. The strength of the orientation, that is, the degree of orientation, can be determined by measuring the ratio of orientation in a specific direction using the above-mentioned polarizing microscope, small-angle X-ray scattering measurement device, or the like.
[0040]
As a method of measuring the degree of orientation in the present invention, the polarization microscope is calculated by measuring the area ratio between the bright field and the dark field in the change of the bright and dark field under crossed Nicols polarization, and the X-ray small angle scattering measurement device Is measured from the intensity ratio of the peak corresponding to the specific surface spacing obtained by irradiating X-rays from all directions. In the present invention, the degree of orientation is preferably, when measured under crossed Nicols polarization of a polarizing microscope, the ratio of the area of the bright field / the area ratio of the dark field is preferably 1.2 or more, more preferably, in the state where the bright field is the largest. 1.5 or more, and when measured by an X-ray small-angle scattering measurement device, in the irradiation direction in which the peak intensity is the highest in the irradiation direction where the peak intensity is the highest in the intensity ratio of the peaks corresponding to the specific plane spacing / Is preferably 1.2 or more, more preferably 2.0 or more.
[0041]
As a method for measuring the ionic conductivity of the ionic conductor, a method for measuring the ionic conductivity from a certain resistance value of the ionic conductor is exemplified. For example, as shown in FIG. 8, an ion conductor 701 is sandwiched between two electrodes 702 and connected as shown in FIG. 8, and the resistance value r of the ion conductor 701 between the two electrodes 702 is measured by an impedance measuring device 703. , The thickness d and the area A of the ion conductor 701 are measured, and the ion conductivity is calculated from the formula: (ion conductivity σ) = d / (A × r). A gap electrode having a length L is brought into close contact with the ion conductor, a resistance value r between the electrodes is measured by an impedance measuring device, a thickness d of the ion conductor is measured, and an equation: (ion conductivity σ) = w / (L × d × r) to calculate the ionic conductivity.
[0042]
Hereinafter, each material used in the present invention will be described in detail.
(Monomer having a side chain containing an alkyl group having 2 or less carbon atoms and a polyether group)
The monomer having a side chain containing an alkyl group having 2 or less carbon atoms and a polyether group may have another functional group as long as it has a structure represented by the following general formula (3). .
Embedded image
General formula (3)

In the above formula, R1 and R2 are each a hydrogen atom or an alkyl group having 2 or less carbon atoms, and preferably a hydrogen atom or a methyl group, which is desirable because the orientation of the polymer compound is improved. R3 is a group having at least an alkyl group having 1 to 4 carbon atoms, and is more preferably a methyl group because the orientation of the polymer compound is improved.
[0043]
Either A or B in the general formula (3) is-(CH₂―CH₂-O)_m-And the other is-(CH₂―CH₂(CH₃) -O)_n-(M and n are preferably integers of 1 to 30). More preferably, m and n are desirably m / n = 0.5 to 2.
[0044]
Preferred examples thereof include methoxy-decaethyleneoxy-block-decapropyleneoxy-acrylate (the number of ethylene oxide and the number of propylene oxide = 10), methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate (ethylene Oxide number, propylene oxide number = 20), methoxy-triacontaethyleneoxy-block-triacontapropyleneoxy-acrylate (ethylene oxide number, propylene oxide number = 30), methoxy-eicosapropyleneoxy-block-eicosaethyleneoxy Acrylate (the number of propylene oxides, the number of ethylene oxides = 20), methoxy-triacontapropyleneoxy-block-decaethyleneoxy-a Relate (propylene oxide number = 30, the number of ethylene oxide: 10), methoxy - penta ethyleneoxy -block- pentadecanoyl propyleneoxy - acrylate (the number of ethylene oxide: 5, propylene oxide number = 15), and the like.
[0045]
(Monomer having a side chain containing an alkyl group having 6 or more carbon atoms and a polyether group)
The monomer having a side chain containing an alkyl group having 6 or more carbon atoms and a polyether group may have another functional group as long as it has a structure represented by the following general formula (4). .
Embedded image
General formula (4)

R4 and R5 in the above formula are each H or an alkyl group having 2 or less carbon atoms, preferably a hydrogen atom (H) or a methyl group. In this case, the orientation of the polymer compound is improved. R6 may have another functional group as long as it has at least an alkyl group having 6 or more carbon atoms, and may be a linear or branched alkyl group. Among them, those containing a straight-chain alkyl group having 6 to 22 carbon atoms or an alkylbenzyl group having a straight-chain alkyl group having 6 to 22 carbon atoms are preferable from the viewpoint of forming an ion conduction path, and those having 8 carbon atoms are preferable. ~ 18 linear alkyl groups are more preferred.
[0046]
X in the general formula (4) may be any group having at least a polyether group, that is, a group containing at least two groups having an ether structure represented by C—O—C. It may have a linear or branched structure. Above all,-(CH₂  -CH₂  -O)_k  More preferably, the group contains at least-(k = 1 to 40).
In the general formula (4), the ratio of the polyether group of X to the alkyl group of R6 is in the range of 0.05 to 3.0 by the molecular weight of the alkyl group of R6 / the molecular weight of the polyether group of X. It is more preferable that the ratio is in the range of 0.1 to 1.0 because the ion conduction path is stably oriented. X is-(CH₂-CH₂  -O)_n  When at least-is contained,-(CH₂  -CH₂-O)_kAnd the ratio of the alkyl group of R6 is the number of carbon atoms of the alkyl group of R3 /-(CH₂  -CH₂  -O)_kThe k number of-is preferably in the range of 0.05 to 10.0, and more preferably in the range of 0.5 to 5.0.
[0047]
Preferred examples thereof include tetraethylene glycol n-octyl ether methacrylate, hexaethylene glycol n-dodecyl ether methacrylate, octaethylene glycol n-hexadecyl ether methacrylate, eicosaethylene glycol n-octadecyl ether methacrylate, and tetraethylene glycol n. -Octyl ether acrylate, hexaethylene glycol n-dodecyl ether acrylate, octaethylene glycol n-hexadecyl ether acrylate, eicosaethylene glycol n-octadecyl ether acrylate, hexaethylene glycol n-nonylphenyl ether methacrylate, eicosaethylene glycol n- Nonylphenyl ether methacrylate and the like That.
[0048]
(Monomer having at least one or more polar groups in the side chain selected from the group consisting of polyether groups, cyano groups, amino groups, amide groups and carbonate groups)
The monomer having one or more polar groups selected from the group consisting of a polyether group, a cyano group, an amino group, an amide group and a carbonate group in the side chain used in the production method of the present invention is represented by the following general formula (5): As long as the monomer has the structure represented by the formula, it may have another functional group.
Embedded image
General formula (5)

[0049]
In the general formula (5), R7 and R8 are each H or an alkyl group having 2 or less carbon atoms, preferably a hydrogen atom (H) or a methyl group. In the latter case, the orientation of the polymer compound is improved. Y may have another functional group as long as it is a group having at least one type of polar group selected from the group consisting of a polyether group, a cyano group, an amino group, an amide group and a carbonate group; It may be a linear or branched alkyl group. In addition, when the ion conductor is used in a lithium battery or the like, the polyether group is preferable because it does not easily react with lithium or the like.₂-CH₂  -O)_n  -Z,-(CH₂  -CH (CH₃  ) -O)_n-Z,-(CH₂  -CH₂  -O)_m  − (CH₂  -CH (CH₃) -O)_n  -Z,-(CH₂  -CH (CH₃  ) -O)_m  − (CH₂-CH₂  -O)_n  -Z,-(CH₂  -CH₂  -O)_l− (CH₂  -CH (CH₃  ) -O)_m  − (CH₂  -CH₂-O)_n  -Z and-(CH₂  -CH (CH₃  ) -O)_l  − (CH₂-CH₂  -O)_m  − (CH₂  -CH (CH₃  ) -O)_nIt is preferably a group containing at least one group selected from the group consisting of -Z (l, m, and n are integers, and Z is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).₂-CH₂  -O)_n  More preferably, it is -Z (n = 2 to 100, Z is H or an alkyl group having 1 to 4 carbon atoms).
[0050]
Preferred examples of these include tetraethylene glycol methyl ether methacrylate, hexaethylene glycol ethyl ether methacrylate, octaethylene glycol n-butyl ether methacrylate, eicosaethylene glycol methyl ether methacrylate, tetraethylene glycol ethyl ether acrylate, and hexaethylene glycol methyl ether. Acrylate, octaethylene glycol methyl ether acrylate, eicosaethylene glycol ethyl ether acrylate, and the like.
[0051]
(Monomer capable of forming a crosslinked structure)
Examples of the third monomer capable of forming a crosslinked structure include a monomer that forms a physical bond such as a hydrogen bond and an ionic bond that forms an ion pair and bonds with a monomer that forms a chemical bond composed of a covalent bond. However, the physical bond such as hydrogen bond may be broken due to temperature change or pH change, and the bond state may change. The monomers that form are preferred. The monomer preferably has a polymerizable functional group capable of polymerizing with three or more other monomers, and has a polymerizable functional group capable of polymerizing with three or more monomers only by a polymerization reaction (step C). Is more preferred. Examples of the polymerization functional group of the monomer include a group capable of forming a covalent bond such as an ester bond, an amide bond, an ether bond, and a urethane bond by condensation polymerization, polycondensation, and ring-opening polymerization, and a vinyl group capable of addition polymerization. Can be Among them, a vinyl group or a cyclic ether is preferable, a vinyl group or an epoxide is more preferable, and a vinyl group is further preferable. In particular, divinyl compounds and trivinyl compounds having two or more vinyl groups are desirable. Examples of the vinyl group include a vinyl group, an allyl group, an acryl group, a methacryl group, and a croton group, and examples of the epoxide include an alkylene oxide such as ethylene oxide, propylene oxide, and glycidyl ether.
[0052]
Among those described above, the monomer capable of forming a crosslinked structure is particularly preferably a monomer represented by the following general formula (6).
Embedded image
General formula (6)

[0053]
In the general formula (6), R9 to R14 are each a hydrogen atom or an alkyl group, and preferably a hydrogen atom or a methyl group. Z1 is a group that forms a cross-linking bond, and is not particularly limited, and is not particularly limited as long as both ends can be bonded as in the general formula (6), but -CO-, -OCOO-, and -CONH- , -CONR-, -OCONH-, -NH-, -NHR-, -SO-, -SO₂-, (R is an alkyl group) and a group having at least one kind of bond or a functional group selected from the group consisting of an ether group are preferable, and a group having two or more ether groups, that is, a group having a polyether group is more preferable.
[0054]
Such specific examples include vinyl acrylate, ethylene glycol dimethacrylate, hexaethylene glycol diacrylate, tridecaethylene glycol diacrylate, eicosaethylene glycol dimethacrylate, N, N'-methylenebisacrylamide, diethylene glycol dimethacrylate, Diethylene glycol bisallyl carbonate, 1,4-butanediol diacrylate, pentadecanediol diacrylate, 1,10-decanediol dimethacrylate, neopentyl glycol dimethacrylate, diallyl ether, diallyl sulfide, glycerin dimethacrylate, 2-hydroxy-3- Acryloylyloxypropyl methacrylate, 2-methacryloxyethyl acid phosphate, dimethyl -Tricyclodecane diacrylate, neopentyl glycol diacrylate hydroxypivalate, bisphenol A diacrylate, ethylene oxide adduct diacrylate of bisphenol A, polytetramethylene glycol dimethacrylate, poly (ethylene glycol-tetramethylene glycol) diacrylate Methacrylate, poly (ethylene glycol-tetramethylene glycol) diacrylate, poly (propylene glycol-tetramethylene glycol) dimethacrylate, poly (propylene glycol-tetramethylene glycol) diacrylate, polyethylene glycol-polypropylene glycol-polytetramethylene glycol) diacrylate Methacrylate, polyethylene glycol-polypropylene glycol-poly Tiger glycol) diacrylate and the like.
[0055]
(solvent)
The solvent used in the method for producing the ionic conductor of the present invention described above with reference to FIG. 2 is a solvent that functions as a plasticizer for the polymer compound of the ionic conductor and does not inhibit the polymerization reaction. If it is possible to use even if the above-mentioned monomers and electrolyte are not completely dissolved, a solvent capable of dissolving the above-mentioned monomers and electrolyte is preferable, and a mixed solution of a solvent that dissolves only the individual monomers and the electrolyte is also desirable, Further, those which dissolve each monomer and the electrolyte and have a high affinity for the polymer compound produced by polymerization are more preferable because a uniform polymer compound can be formed. In the case where this solvent is removed in a later step, it is desirable to select a highly volatile solvent.
[0056]
Specific examples of such a solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, ethylene glycol, glycerin, diethyl ether, diisopropyl ether, tetrahydrofuran, tetrahydropyran, 1,2-methoxyethane, diethylene glycol Dimethyl ether, acetone, ethyl methyl ketone, cyclohexanone, ethyl acetate, butyl acetate, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, 1, 3-dimethyl-2-imidazolidinone, N-methylpyrrolidone, acetonitrile, propionitrile, slicinonitrile, benzo Tolyl, ethylenediamine, triethyleneamine, aniline, pyridine, piperidine, morpholine, methylene chloride, chloroform, 1,2-dichloroethane, chlorobenzene, 1-bromo-2-chloroethane, nitromethane, nitrobenzene, o-nitrotoluene, diethoxyethane, , 2-Dimethoxyethane, γ-butyrolactone, dioxolan, sulfolane, dimethylsulfide, dimethylsulfoxide, dimethoxyethane, methyl formate, 3-methyl-2-oxazolidinone, 2-methyltetrahydrofuran, sulfur dioxide, phosphoryl chloride, thionyl chloride, chloride Sulfuryl and the like. These solvents may be used alone or in combination of two or more of them.
[0057]
When a solvent in which the above monomers are not completely dissolved is used, a method in which a dispersant such as a surfactant is added to the solvent is also possible. At this time, the amount of the dispersant to be added is preferably 4% by weight or less, preferably 3% by weight or less based on the solvent. When the dispersant is added in an amount of more than 4% by weight, the orientation during the formation of the ion conduction path is liable to decrease, and the amount of the dispersant remaining even after washing increases, so that the dispersant easily inhibits ion conduction. And the ion conductivity tends to decrease.
[0058]
(Polymerization initiator)
Examples of the polymerization initiator used in the method for producing an ion conductor of the present invention include polymerization initiators suitable for polymerization methods such as polycondensation, addition polymerization, and ring-opening polymerization, and radical polymerization, cationic polymerization, and anionic polymerization. Select and use. Specific examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile, peroxides such as benzoyl peroxide, potassium persulfate, ammonium persulfate, photoabsorption and decomposition compounds of ketone compounds and metallocene compounds, and the like.₂SO₄  , H₃  PO₄  , HClO₄  , CCl₃CO₂  Acids such as H, BF₃  , AlCl₃  , TiCl₄  , SnCl₄Friedel-Crafts catalysts such as₂  , (C₆  H₅  )₃  CCl, alkali metal compounds, magnesium compounds, and the like. The amount of the polymerization initiator to be added to the monomer is preferably in the range of 0.001 to 10% by weight based on the weight of all monomers in terms of the monomer polymerization efficiency and the degree of polymerization, and the mechanical strength is good Therefore, the range of 0.01 to 5% by weight is more preferable.
[0059]
(Electrolytes)
Examples of the electrolyte used in the method for producing an ion conductor of the present invention include cations such as lithium ions, sodium ions, potassium ions, and tetraalkylammonium ions, and Lewis acid ions (BF₄ ⁻, PF₆  ⁻, AsF₆  ^―, ClO₄ ⁻, CF₃  SO₃  ⁻, (CF₃  SO₂)₂  N⁻, (CF₃  SO₂  )₃  C⁻, BPh₄ ⁻(Ph: phenyl group)), hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide, and mixtures thereof. Especially, a lithium salt is preferable.
[0060]
Analysis of the composition and chemical structure of the high molecular compound constituting the skeleton of the ion conductor manufactured using the above-described materials by the method for manufacturing the ion conductor of the present invention can be performed by using an infrared absorption spectrum apparatus or a visible ultraviolet absorption A method for analyzing the composition of bonds and atomic groups with a spectrum device, a method for analyzing the composition and structure of bonds and atomic groups with a nuclear magnetic resonance spectrometer, an electron spin resonance spectrometer and an optical rotation dispersing device, and a method for analyzing the composition and structure of atomic groups with a mass spectrum device Performed by a method of analyzing composition, a method of measuring the composition such as the composition of an atomic group or the degree of polymerization by various chromatography such as liquid chromatography and gas chromatography, and a method of identifying and quantifying by a direct titration method of a functional group. be able to. At this time, the measurement sample is measured as it is or after being chemically decomposed or the like according to the measurement method.
[0061]
(Method of Manufacturing Secondary Battery of the Present Invention)
The method for manufacturing the secondary battery of the present invention will be described. The method for manufacturing a secondary battery according to the present invention typically uses the ion conductor manufactured by the above-described method for manufacturing an ion conductor so that the ion conductivity is highest in a direction connecting the negative electrode surface and the positive electrode surface. In this method, a secondary battery is manufactured by providing an output terminal in contact with a negative electrode and a positive electrode, taking out an output terminal, and sealing the output terminal with an exterior material.
[0062]
Specific shapes of the secondary battery in the present invention include, for example, a flat shape, a cylindrical shape, a rectangular parallelepiped shape, and a sheet shape. The structure of the secondary battery includes, for example, a single layer type, a multilayer type, a spiral type, and the like. Among them, a spiral cylindrical battery is characterized in that the electrode area can be increased by winding a separator between the negative electrode and the positive electrode, and a large current can flow during charging and discharging. Further, a rectangular parallelepiped or sheet type battery has a feature that a storage space of a device configured to store a plurality of batteries can be effectively used.
[0063]
FIG. 5 is a schematic cross-sectional view schematically showing a configuration of a specific example of a single-layer sheet type secondary battery. In FIG. 5, reference numeral 401 denotes an ion conductor, 402 denotes a negative electrode current collector, 403 denotes a negative electrode active material (negative electrode material), 404 denotes a negative electrode, 405 denotes a positive electrode active material (positive material), 406 denotes a positive electrode current collector, and 407 denotes a positive electrode current collector. The positive electrode, 408 indicates an exterior material, and 409 indicates an electrode laminate.
FIG. 6 is a schematic cross-sectional view schematically showing a configuration of a specific example of a single-layer flat (coin-type) secondary battery. This secondary battery has basically the same configuration as that of FIG. In FIG. 6, 501 denotes a negative electrode, 502 denotes an ion conductor, 503 denotes a positive electrode, 504 denotes a negative electrode can (negative electrode terminal), 505 denotes a positive electrode can (positive electrode terminal), and 506 denotes a gasket.
Although only a single-layer secondary battery is shown in the figure, a multi-layer secondary battery in which an ionic conductor is interposed between a negative electrode and a positive electrode and stacked in multiple layers may be used.
[0064]
By using the ionic conductor of the present invention, the electrolyte can be solidified between the negative electrode and the positive electrode, so that there is no liquid leakage, and the sealing of the battery is easy. Thus, a secondary battery having a free shape can be easily manufactured.
[0065]
The secondary battery illustrated in FIG. 5 uses the above-described ion conductor, forms an electrode stack 409 having a structure in which the ion conductor is sandwiched between the negative electrode 404 and the positive electrode 407, and obtains the obtained electrode stack 409. Can be manufactured by sealing with a packaging material 408. A specific example of a method for forming the electrode stack 409 will be described below.
[0066]
(Method 1 for forming electrode laminate 409)
A thin-film ion conductor is formed on the surface of the negative electrode 404, the surface of the positive electrode 407, or both surfaces of the negative electrode 404 and the positive electrode 407 by the above-described method for manufacturing an ion conductor. Then, the negative electrode 404 and the positive electrode 407 are adhered to each other with the surface on which the ion conductor is provided facing each other, or a similar thin-film ion conductor is further interposed between the negative electrode 404 and the positive electrode 407 to form the electrode laminate 409. Form. At this time, in order to improve the adhesion between the initially formed ion conductor and the electrode, between the ion conductor and the negative electrode 404 and between the ion conductor and the positive electrode 407 or between the ion conductor and the negative electrode 404 or the positive electrode 407. A polymer precursor, which is a raw material of the ion conductor, is inserted between the ion conductors formed between them, and the inserted polymer precursor is polymerized by heating after adhesion, thereby forming an adhesive layer made of the ion conductor. Preferably, it is formed. Further, in order to improve the orientation of the polymer skeleton in the adhesive layer, the step (a) of heating the produced electrode laminate to a temperature equal to or higher than the temperature at which the monomer contained in the polymer precursor exhibits the orientation. It is preferable to perform a process of repeating the step (b) of performing the step (b) of cooling the monomer to a temperature at which the monomer exhibits orientation or less once or more. At this time, the electrode laminate is kept at a constant temperature during the heating of the electrode laminate in the step (a), and the temperature is preferably 10 to 200 ° C. higher than the temperature at which the monomer exhibits orientation. It is more preferable that the temperature is higher by 100 ° C. Further, the electrode laminate is kept at a constant temperature during the cooling of the electrode laminate in the step (b), and the temperature is preferably 0 to 100 ° C. lower than the temperature at which the monomer exhibits orientation. More preferably, it is lower by 50 ° C. When heating or cooling the electrode laminate in the steps (a) and (b), the electrode laminate is kept at a constant temperature as described above, and the holding time is preferably from 5 to 120 minutes, more preferably from 10 to 60 minutes. preferable.
[0067]
(Method 2 for forming electrode laminate 409)
The electrode stack is sandwiched between the negative electrode 404 and the positive electrode 407 so that the negative electrode 404 and the positive electrode 407 face and adhere to both surfaces of the film-shaped ion conductor produced by the method for manufacturing the ion conductor described above. A body 409 is formed. At this time, if the ion conductor is allowed to enter gaps in the electrode active materials (403, 405) of the negative electrode 404 and the positive electrode 407, the charge and discharge efficiency is improved. Preferably, an ionic conductor is formed. At this time, in order to improve the adhesiveness between the ion conductor and the electrode, when the negative electrode 404 and the positive electrode 407 are brought into close contact with the ion conductor interposed therebetween, the gap between the ion conductor and the negative electrode 404 and It is preferable that a polymer precursor, which is a raw material of an ion conductor, is inserted between the positive electrode 407 and the polymer precursor that is inserted by heating after adhesion, thereby polymerizing the inserted polymer precursor to form an adhesive layer made of the ion conductor. Further, in order to improve the orientation of the polymer skeleton in the adhesive layer, the produced electrode laminate is subjected to a step (a) of heating the monomer contained in the polymer precursor to a temperature at which the monomer exhibits orientation, or more. Next, it is preferable to carry out a process of repeating a cycle of performing the step (b) of cooling the monomer to a temperature at which the monomer exhibits orientation or less once or more. At this time, the electrode laminate is kept at a constant temperature during the heating of the electrode laminate in the step (a), and the temperature is preferably 10 to 200 ° C. higher than the temperature at which the monomer exhibits orientation. It is more preferable that the temperature is higher by 100 ° C. Further, the electrode laminate is kept at a constant temperature during the cooling of the electrode laminate in the step (b), and the temperature is preferably 0 to 100 ° C. lower than the temperature at which the monomer exhibits orientation. More preferably, it is lower by 50 ° C. When heating or cooling the electrode laminate in the steps (a) and (b), the electrode laminate is kept at a constant temperature as described above, and the holding time is preferably from 5 to 120 minutes, more preferably from 10 to 60 minutes. preferable.
[0068]
In the flat-type (coin-type) secondary battery illustrated in FIG. 6, a positive electrode 503 including a positive electrode material layer (active material layer) and a negative electrode 501 including a negative electrode material layer (active material layer) include at least an ion conductor 502. The stacked body is accommodated from the positive electrode side in a positive electrode can 505 as a positive electrode terminal, and the negative electrode side is covered with a negative electrode cap 504 as a negative electrode terminal. Then, a gasket 506 is arranged in another portion inside the positive electrode can.
[0069]
The assembly of the secondary battery shown in FIG. 6 is performed, for example, as follows.
(1) An electrode laminate having an ion conductor (502) sandwiched between a negative electrode (501) and a positive electrode (503) is formed by the above-described method 1 or 2 of forming an electrode laminate, and a positive electrode can (505) is formed. ).
(2) Assemble the negative electrode cap (504)) and the gasket (506).
(3) By caulking the battery obtained in the above (2), a battery is completed.
It is desirable that the above-described preparation of the battery material and assembly of the battery be performed in dry air from which moisture is sufficiently removed or in a dry inert gas.
[0070]
Hereinafter, the components of the secondary battery will be described in more detail with reference to FIG.
(Negative electrode)
The negative electrode 404 includes a current collector 402 and an active material layer 403. In the present invention, the term “active material” means a substance that participates in the electrochemical reaction of charging and discharging (repetition of charge / discharge reaction) in a secondary battery.
[0071]
When the secondary battery of the present invention is a lithium secondary battery using an oxidation-reduction reaction of lithium ions, the material used for the active material layer of the negative electrode is one that retains lithium during charging, lithium metal, and lithium. Examples include a metal that is electrochemically alloyed, a carbon material or a transition metal compound that intercalates lithium. Examples of the metal which electrochemically alloys with lithium include Bi, In, Pb, Si, Ag, Sr, Ge, Zn, Sn, Cd, Sb, Tl, and Hg. Is preferable because the alloy has good adhesion to the ion conductor, and an amorphous alloy of Sn is more preferable. Examples of the transition metal compound include a transition metal oxide, a transition metal nitride, a transition metal sulfide, and a transition metal carbide. Examples of the transition metal element of these transition metal compounds include Sc, Y, lanthanoids, actinoids, Ti, Zr, Hf, V, Nb, Ta, which are elements having a partially d- or f-shell. Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au. Particularly, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu, which are the first transition series metals, are preferable.
[0072]
If the negative electrode active material is in a powder form, a binder is mixed with the negative electrode active material, and in some cases, a conductive auxiliary material is also added, and a negative electrode active material layer 403 is formed on the current collector by coating or pressing, and a foil is formed. In the case of a negative electrode or a plate, the negative electrode is formed by pasting on a current collector with a press or the like. Alternatively, a method of forming a thin film of the above material on the current collector by plating or vapor deposition may be used. Examples of the vapor deposition method include CVD (Chemical Vapor Deposition), electron beam vapor deposition, and sputtering. It is necessary that all negative electrodes for lithium secondary batteries be sufficiently dried under reduced pressure.
[0073]
As the binder used for forming the active material layer 403 of the negative electrode 404, for example, a polyolefin such as polyethylene or polypropylene, or a fluororesin such as polyvinylidene fluoride or tetrafluoroethylene polymer, polyvinyl alcohol, cellulose, or polyamide However, when an ion conductor is directly formed on the negative electrode 404, it is preferable to use a hydrophobic binder such as a fluororesin because the orientation of the polymer compound is further improved.
[0074]
The current collector 402 of the negative electrode 404 has a role of efficiently supplying a current consumed in an electrode reaction at the time of charging / discharging or collecting current generated. Therefore, as a constituent material of the current collector 402, a material having high conductivity and inert to a battery reaction is desirable. Such preferred materials include nickel, titanium, copper, aluminum, stainless steel, platinum, palladium, gold, zinc, various alloys, and composite metal materials composed of two or more of these materials. As the shape of the current collector 402, for example, a plate shape, a foil shape, a mesh shape, a sponge shape, a fiber shape, a punching metal, an expanded metal, or the like can be adopted.
[0075]
(Positive electrode)
The positive electrode 407 includes a current collector 406 and an active material layer 405. In the case where the secondary battery of the present invention is a lithium secondary battery utilizing an oxidation-reduction reaction of lithium ions, the material used for the active material layer 405 of the positive electrode 407 is one that retains lithium at the time of discharging, and intercalates lithium. Transition metal oxides, transition metal nitrides, transition metal sulfides, and the like. Examples of the transition metal element of these transition metal compounds include Sc, Y, lanthanoids, actinoids, Ti, Zr, Hf, V, Nb, Ta, which are elements having a partially d- or f-shell. Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au. Particularly, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu, which are the first transition series metals, are preferable. When a negative electrode active material containing no lithium is used at the time of assembling the battery, it is preferable to use a compound containing lithium in advance, such as a lithium transition metal oxide, as the positive electrode active material.
[0076]
The positive electrode 407 includes a current collector 406, a positive electrode active material, a conductive auxiliary material, a binder, and the like. The positive electrode 407 is manufactured by arranging and mixing a mixture of a positive electrode active material, a conductive auxiliary material, a binder, and the like on the current collector 406.
[0077]
Examples of the conductive auxiliary agent used for the positive electrode 407 include graphite, carbon black such as Ketjen black and acetylene black, and fine metal powder such as nickel. Examples of the binder used for the positive electrode 407 include polyolefins such as polyethylene and polypropylene, or fluororesins such as polyvinylidene fluoride and tetrafluoroethylene polymers, polyvinyl alcohol, cellulose, and polyamide. In the case where an ion conductor is directly formed by using the method described above, it is desirable to use a hydrophobic binder such as a fluororesin because the orientation of the polymer compound is further improved.
[0078]
The current collector 406 has a role of efficiently supplying a current consumed by an electrode reaction at the time of charging / discharging or collecting current generated. Therefore, as a constituent material of the current collector 406, a material having high conductivity and inert to a battery reaction is desirable. Such preferred materials include nickel, titanium, aluminum, stainless steel, platinum, palladium, gold, zinc, various alloys, and composite metal materials composed of two or more of these materials. As the shape of the current collector 406, for example, a shape such as a plate shape, a foil shape, a mesh shape, a sponge shape, a fiber shape, a punching metal, an expanded metal, or the like can be adopted.
[0079]
(Insulation packing)
As a material of the gasket (506), for example, a fluorine resin, a polyolefin resin, a polyamide resin, a polysulfone resin, and various rubbers can be used.
(Exterior material / battery housing)
In the example shown in FIG. 6, the battery housing for accommodating each member in the secondary battery includes a positive electrode can 505 and a negative electrode cap 504 of the battery. In the example shown in FIG. 6, since the positive electrode can 505 and the negative electrode cap 504 also serve as the battery housing (case) and the input / output terminals, stainless steel is preferably used. When the battery exterior material 408 does not double as a housing as in the example shown in FIG. 5, a plastic material such as a plate-like or film-like plastic material, a metal foil or a laminated film obtained by laminating a metal film with a plastic film is used. And a metal composite material are suitably used. When the secondary battery of the present invention is a lithium secondary battery, it is more preferable to use a material that does not transmit water vapor or gas as the exterior material, and it is important that the material can be sealed so as to block the water vapor intrusion path.
[0080]
【Example】
The present invention will be described in more detail with reference to the following examples. However, these examples are illustrative, and the present invention is not limited by these examples. Hereinafter, "parts" related to the amount in the examples means parts by weight.
[0081]
Embodiment 1
In this example, an ionic conductor was manufactured as described below.
(1) Preparation of ion conductor:
Methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate (number of ethylene oxide, number of propylene oxide = 20) was used as a monomer having a polyether group as a first monomer in a side chain. First, the temperature indicating the orientation was measured. The melting point of the first monomer measured by differential thermal analysis (DSC) was around 12 ° C. (FIG. 3). When the orientation of the monomer was observed under crossed Nicols polarization with changing the temperature, a change from dark field to bright field was observed at 12 ° C. or lower. Therefore, in the case of the first monomer, it was found that the temperature at which the orientation was exhibited was 12 ° C. 150 parts of this first monomer, 10 parts of methoxytripropylene glycol acrylate as a second monomer, 1.8 parts of poly (ethylene glycol tetramethylene glycol dimethacrylate) as a cross-linking agent, and 2,2-dimethoxy- 1 mol of 2-phenylacetophenone was mixed and dissolved in a solution in which lithium tetrafluoroborate was mixed with ethylene carbonate and γ-butyl lactone at a volume ratio of 3: 7, 2 mol / dm 2³Was added to obtain a polymer precursor (L1). Then, this polymer precursor (L1) was placed in a cell (polymerization vessel 301 in FIG. 5) in which two quartz plates each having a fluororesin layer formed on one side and spacers (thickness: 50 μm) made of Teflon (registered trademark) were formed. Inserted. After placing the polymerization vessel in a thermostat set at −20 ° C. to orient the monomers in the polymer precursor, 10 mW / cm²Was irradiated for 1 hour to carry out a polymerization reaction and a crosslinking reaction, and the temperature of the constant temperature bath was set to 25 ° C. to obtain an ion conductor (10 cm wide × 6 cm long × 50 μm thick).
[0082]
Thereafter, the temperature of the constant temperature bath is increased at a rate of 1 ° C. per minute, and when the temperature reaches 40 ° C., a heating step of keeping the temperature for 10 minutes is performed. Then, the temperature of the constant temperature bath is decreased at a rate of 1 ° C. per minute. When the temperature reached −20 ° C., a cycle of performing a cooling step of keeping the temperature at that temperature for 10 minutes was defined as one cycle, and after repeating this cycle five times, the temperature of the thermostat was set to 25 ° C.
Before and after this cycle treatment step, the orientation of the obtained ion conductor was measured with a polarizing microscope, a viscoelasticity measuring device (DMS) and a small-angle X-ray scattering measuring device as shown below. The ionic conductivity was also measured.
[0083]
(2) Orientation measurement-polarizing microscope:
The film surface of the obtained film-like ion conductor was observed under crossed Nicols polarization using a polarizing microscope. A change from dark field to bright field was observed uniformly over the entire surface of the film before and after the above-mentioned heating step-cooling cycle cycle treatment.
[0084]
(3) Measurement of orientation—X-ray small angle scattering:
The relaxation temperature of the side chain of the polymer chain is measured with a viscoelasticity measuring device (DMS), and the ion conductor is measured in a direction parallel to the film surface (X-axis and Y-axis directions) with a small-angle X-ray scattering measuring device. The measurement was performed at room temperature, which is equal to or lower than the relaxation temperature of the side chain portion, from all directions including the thickness direction and the thickness direction (Z axis). At the time of this measurement, the measurement was performed while adjusting the sample shape so as to be constant in the measurement direction.
As a result, when measured in the thickness direction (Z-axis direction) with respect to the film surface, the peak in FIG. 7 appears, and when measured from another direction, the peak intensity at this position is the peak intensity in the Z-axis direction. It was much smaller than the strength. At this time, the peak intensity in the Z-axis direction is 6 times (before the above-mentioned heating step-cooling step cycle repetition process) and 8 times (the above-mentioned heating step-cooling step) the peak intensity ratio with respect to the direction of the weakest peak intensity After the cycle repetition treatment). Further, a peak appears at a position different from the peak position in FIG. 7 in the direction along the X axis (X axis direction) of the film surface, and the peak at this position is other than the direction along the film surface (XY plane direction). Did not appear. At this time, the peak intensity is the strongest in the X-axis direction, and 9 times the peak intensity ratio in the direction of the weakest peak intensity in the other XY plane directions (excluding the X-axis direction) (the cycle of the heating step-cooling step). (Before the repetitive treatment) and 11 times (after the repetition of the heating step-cooling step cycle).
Next, when the measurement sample was heated to 100 ° C. above the relaxation temperature of the side chain portion and measured in the thickness direction (Z-axis) with respect to the film surface, the peak in FIG. Was observed, and the orientation of the side chain portion as shown in FIG. 1A was broken by heating. Such a change was hardly observed except in the direction perpendicular to the film surface.
From the above results, the obtained ion conductor was considered to be considered that the main chain portion of the polymer chain was parallel to the film surface and the side chain portion was oriented in the thickness direction. In addition, after the above-mentioned heating step-cooling step cycle repetition treatment, the orientation of the main chain part / side chain part became stronger than before the treatment.
The results are shown in Table 1 below.
[0085]
(4) Measurement of ionic conductivity:
As shown in FIG. 8, the film-like ion conductor (701) obtained in the above (1) is sandwiched between two stainless steel electrodes 702, and connected to an impedance measuring device 703 composed of a milliohm meter. The resistance value of the ion conductor 701 between 702 was measured by the impedance measuring device 703. The resistance value of the ion conductor 701 is measured by measuring the impedance with an input voltage of 0.1 V and a sine wave measurement signal of 1 kilohertz, obtaining the resistance value r, and measuring the thickness d and the area A of the ion conductor 701. Then, the ion conductivity in the thickness direction of the ion conductor 701 was calculated from the equation (ion conductivity σ) = d / (A × r).
Also, the film-shaped ion conductor was adhered to the gap electrode prepared by e-beam evaporation of aluminum by attaching the mask of the negative pattern of the gap electrode to the glass substrate, and the resistance value of the ion conductor of both electrodes. Was measured. The measurement was performed using an impedance measuring device composed of a milliohm meter in the same manner as in the above measurement, and the impedance was measured with a measurement signal of 1 kHz in the same manner as described above, the resistance value r was obtained, and the thickness d of the ion conductor was measured. The ionic conductivity of the ionic conductor in the film surface direction was calculated from (ionic conductivity σ) = (gap width w between gap electrodes) / (gap electrode length L × d × r). The ion conductivity of this film-like ion conductor is 9 times (those before the cycle of the heating step-cooling step) and 13 times (the cycle of the heating step-cooling step) the thickness direction of the film surface direction. After), the anisotropic ion conductivity was obtained, and the anisotropy thereof increased after the above-described heating-cooling cycle cycling treatment. Further, the ionic conductivity at a low temperature was also measured, and was better than that of the comparative example. After the above-described cycle of the heating step and the cooling step, the ionic conductivity in the thickness direction of the ionic conductor increased. The results are shown in Table 1 below.
[0086]
(5) Confirmation of crosslinked structure and unreacted monomer:
When the obtained ion conductor was analyzed with an infrared absorption spectrometer, a nuclear magnetic resonance spectrometer and a mass spectrometer, it was expected that the crosslinked structure formed by polymerization of the monomers at the ratio at the time of preparation was obtained. Results. For confirmation, when the obtained ionic conductor was gradually heated to 300 ° C, no melting phenomenon was observed just because it was oxidized, and a crosslinked structure in which the polymer skeleton was chemically bonded was formed. It was confirmed. Further, in order to analyze the ratio of the unreacted monomer in the obtained ion conductor, the ion conductor was immersed in a tetrahydrofuran solution for one day, and then the tetrahydrofuran solution was analyzed by gel permeation chromatography (GPC). No unreacted monomer or low molecular weight polymerization reaction product was observed, and it was considered that all monomers were considered to be chemically bonded in the polymer skeleton.
[0087]
Embodiment 2
The procedure was performed in the same manner as in Example 1 except that the polymerization temperature when forming the ion conductor and the temperature of the cooling step in the cycle-repeating process of the heating step and the cooling step of the produced ion conductor were set to 0 ° C.
[0088]
Embodiment 3
The same procedure as in Example 1 was performed, except that the temperature of the cooling step in the cycle repetition treatment of the heating step and the cooling step of the produced ion conductor was set to 15 ° C.
[0089]
Embodiment 4
The procedure was performed in the same manner as in Example 1 except that the number of cycles of the heating step-cooling step for the produced ion conductor was set to two.
[0090]
Embodiment 5
The procedure was performed in the same manner as in Example 1 except that the produced ion conductor was not subjected to the heating step-cooling step cycle repetition treatment.
[0091]
Embodiment 6
Example 1 was carried out in the same manner as in Example 1 except that the polymer precursor (L2) shown below was used instead of the polymer precursor (L1) used in Example 1.
Polymer precursor (L2):
A monomer having an alkyl group and a polyether group was used instead of the first monomer of the polymer precursor (L1). The composition was 154 parts of n-octadecyl polyethylene glycol (ethylene oxide number = 30) acrylate having an alkyl group having 18 carbon atoms as the first monomer, and polyethylene glycol (ethylene oxide number = 3) methyl methacrylate of the second monomer. 10 parts of methoxytripropylene glycol acrylate, 19 parts of polyethylene glycol tetramethylene glycol dimethacrylate as a cross-linking agent, and 1 part of 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator were mixed with lithium tetrafluoroborate. Was dissolved in a solution in which ethylene carbonate and γ-butyl lactone were mixed in a volume ratio of 3: 7 to 2 mol / dm.³Was added to obtain a polymer precursor (L2). The temperature at which the first monomer exhibited orientation was 46 ° C.
[0092]
Embodiment 7
Example 1 was carried out in the same manner as in Example 1 except that the first monomer of the polymer precursor (L1) used in Example 1 had a different number of ethylene oxide and propylene oxide shown below.
First monomer:
A monomer having ethylene oxide number = 11 and propylene oxide number = 27 instead of methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate (the number of ethylene oxide and the number of propylene oxide = 20); -Block-heptaicosa propylene oxy-acrylate was used. The temperature at which the first monomer exhibited orientation was 25 ° C.
[0093]
The orientation of the ion conductors obtained in Examples 2 to 7 was measured in the same manner as in Example 1 using a polarizing microscope, a viscoelasticity measuring device (DMS), and a small-angle X-ray scattering measuring device. As a result, in the obtained ion conductor, the main chain of the polymer chain was considered to be oriented parallel to the film surface and the side chain was oriented in the thickness direction. It was found that in Examples 2, 4, 6, and 7, this orientation was increased before and after, and no change was observed in Examples 3 and 5. Furthermore, when the ionic conductivity of the ionic conductor was measured in the same manner as in Example 1, the result was that the ionic conductor had anisotropic ionic conductivity. When compared with the results before and after the heating step-cooling cycle cycle treatment in Example 1, in Examples 2, 4, 6, and 7, the anisotropic conductivity increases before and after the heating step-cooling cycle cycle treatment, It was found that there was no change in Examples 3 and 5. Furthermore, when the ionic conductivity at a low temperature was also measured, it was better than the comparative example. The results are shown in Table 1 below.
[0094]
[Comparative Example 1]
The procedure was performed in the same manner as in Example 1 except that the polymerization temperature at the time of forming the ion conductor was 25 ° C.
[0095]
[Comparative Example 2]
The procedure was performed in the same manner as in Example 1 except that the polymerization temperature at the time of forming the ion conductor was 25 ° C., and the cycle treatment of the heating step and the cooling step was not performed on the produced ion conductor.
[0096]
The ionic conductors obtained in Comparative Examples 1 and 2 were measured for orientation using a polarizing microscope, a viscoelasticity measuring device (DMS) and a small-angle X-ray scattering measuring device in the same manner as in Example 1, and were obtained. In the ionic conductor, the main chain portion of the polymer chain was considered to be oriented parallel to the film surface and the side chain portion was oriented in the thickness direction. In all cases, Example 1 had better orientation. it was high. Comparing the ionic conductor of Comparative Example 1 after the heat treatment-cooling cycle cycle treatment with that obtained in Comparative Example 2, Comparative Example 1 showed slightly higher orientation. Further, when the ionic conductivity of the ionic conductor was measured in the same manner as in Example 1, the result was that the ionic conductor had anisotropic ionic conductivity. it was high. Comparing the ionic conductor of Comparative Example 1 after the heat treatment-cooling cycle cycle treatment and that obtained in Comparative Example 2, Comparative Example 1 had slightly higher anisotropic ionic conductivity.
[0097]
[Comparative Example 3]
Example 1 was carried out in the same manner as in Example 1 except that the following polymer precursor (L3) was used instead of the polymer precursor (L1).
Polymer precursor (L3):
6.1 parts of acrylic acid as a monomer, 1.8 parts of poly (ethylene glycol tetramethylene glycol dimethacrylate) as a crosslinking agent, and 0.025 part of 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator were mixed. 2 mol / dm of lithium fluoroborate dissolved in a solution of ethylene carbonate and γ-butyl lactone mixed in a volume ratio of 3: 7³Was prepared by adding 150.6 parts of an electrolytic solution of
The temperature at which acrylic acid as the first monomer exhibited orientation was measured. Although the melting point measured by differential thermal analysis (DSC) was around 13 ° C., when the temperature was changed in the range of −20 ° C. to 20 ° C., and the orientation was observed under crossed Nicols polarization, the dark field was observed at any temperature. And did not show any orientation.
The orientation of the ion conductor obtained in Comparative Example 3 was measured using a polarizing microscope, a viscoelasticity measuring device (DMS) and an X-ray small angle scattering measuring device in the same manner as in Example 1, and the obtained ions were measured. It was considered that the conductor had no orientation in both the main chain and the side chain of the polymer chain before and after the heat treatment-cooling cycle repeated treatment. Furthermore, when the ionic conductivity of this ionic conductor was measured in the same manner as in Example 1, there was no anisotropy in the ionic conductivity.
[0098]
[Table 1]

[0099]
Embodiment 8
In this example, a sheet-type secondary battery having the configuration shown in FIG. 5 was manufactured.
That is, first, a negative electrode and a positive electrode are prepared, and an ion conductor is formed on both surfaces of the obtained negative electrode and the positive electrode. Then, a polymer precursor is applied to the surface of the ion conductor, and both surfaces of the porous film of the support are coated. After the negative electrode and the positive electrode were opposed to each other and bonded together, the resultant was sealed with a moisture-proof film, which is a laminate film of polypropylene / aluminum foil / polyethylene terephthalate, and then polymerized with a polymer precursor. Further, a process of heating and then cooling was repeated several times to produce the sheet type secondary battery. The procedure for fabricating this secondary battery will be described below with reference to FIG.
1. Preparation of the negative electrode 404
After 90 parts of natural graphite fine powder heat-treated at 2000 ° C. in an argon gas stream was mixed with 10 parts of polyvinylidene fluoride powder, 100 parts of N-methyl-2-pyrrolidone was added to prepare a paste. The obtained paste was applied to a current collector 402 made of a copper foil, and dried at 150 ° C. under reduced pressure. Next, it was cut into a predetermined size, and a lead of a nickel wire was connected to the current collector 402 by spot welding to obtain a negative electrode 404.
2. Preparation of positive electrode 407
After 90 parts of lithium cobaltate powder was mixed with 5 parts of acetylene black and 5 parts of polyvinylidene fluoride, 100 parts of N-methyl-2-pyrrolidone was added to prepare a paste. The obtained paste was applied to a current collector 406 as an aluminum foil and dried, and then the positive electrode active material layer was pressed with a roll press. Further, an aluminum lead was connected with an ultrasonic welding machine and dried under reduced pressure at 150 ° C. to obtain a positive electrode 407.
[0100]
3. Formation of ionic conductor on electrode surface
(1) First, a monomer having a polyether group as a first monomer in a side chain: methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate (the number of ethylene oxide, the number of propylene oxide = 20) is oriented. Was measured. The melting point of the monomer measured by differential thermal analysis (DSC) was around 12 ° C. (FIG. 3). When the orientation of the monomer was observed under crossed Nicols polarization with changing the temperature, a change from dark field to bright field was observed at 12 ° C. or less. Therefore, in the case of this monomer, the temperature at which orientation was exhibited was 12 ° C. All the following operations were performed in an argon gas atmosphere. 150 parts of the first monomer, 10 parts of methoxytripropylene glycol acrylate as the second monomer, 1.8 parts of poly (ethylene glycol tetramethylene glycol dimethacrylate) as the crosslinking agent, 2,2-dimethoxy-2 as the photopolymerization initiator 1 mol of phenylacetophenone and 2 mol / dm 2 of lithium tetrafluoroborate dissolved in a solution of ethylene carbonate and γ-butyl lactone in a volume ratio of 3: 7³Was added to obtain a polymer precursor (L1).
[0101]
The obtained polymer precursor (L1) was made of Teflon (registered trademark) such that the active material side of the negative electrode 404 obtained in 1 above and the resin layer side of the quartz plate having the fluororesin layer formed on one side faced each other. It was inserted into a cell (polymerization container 301 in FIG. 4) formed via a spacer (thickness: 10 μm). After placing the polymerization vessel in a thermostat set at −20 ° C. to orient the monomers, 10 mW / cm²Was irradiated for 1 hour to cause a polymerization reaction and a crosslinking reaction, and then the temperature of the constant temperature bath was set to 25 ° C. Thereafter, the temperature of the constant temperature bath is increased at a rate of 1 ° C. per minute, and when the temperature reaches 40 ° C., a heating step of keeping the temperature for 10 minutes is performed. Then, the temperature of the constant temperature bath is decreased at a rate of 1 ° C. per minute. When the temperature reached −20 ° C., a cycle of performing a cooling step of keeping the temperature at that temperature for 10 minutes was defined as one cycle, and after repeating this cycle five times, the temperature of the thermostat was set to 25 ° C. Thus, an ion conductor was formed on the negative electrode 404.
In the same manner as described above, an ionic conductor was also formed on the positive electrode 407 obtained in the above item 2.
[0102]
4. Assembling the secondary battery
The assembling operation of the secondary battery was performed in an argon gas atmosphere.
Polymer precursor (H1) using 1 part of azobisisobutyronitrile as a thermal polymerization initiator instead of 1 part of photopolymerization initiator 2,2-dimethoxy-2-phenylacetophenone of polymer precursor (L1) Was prepared. The polymer precursor (H1) is applied to the surface of the ion conductor of the negative electrode 404 and the positive electrode 407 in which the ion conductor is formed in the above 3 so that the ion conductors formed on the surfaces of the negative electrode 404 and the positive electrode 407 face each other. The negative electrode 404 and the positive electrode 407 were adhered to each other via a polyethylene porous film to obtain an electrode laminate 409. After reducing the pressure of the electrode laminate to 5.3 kPa for 10 minutes, the pressure was returned to normal pressure and maintained for 10 minutes. After repeating the same operation (reduced pressure for 10 minutes → normal pressure for 10 minutes) twice, the electrode laminate 409 was sealed with a moisture-proof film that was a laminate film of polypropylene / aluminum foil / polyethylene terephthalate. Thereafter, the mixture was heated to 60 ° C. to perform a polymerization reaction for 3 hours. Then, in the same manner as in 3 above, the electrode laminate 409 is repeatedly subjected to a heating step-cooling cycle cycle five times, then the temperature of the electrode laminate 409 is set to 25 ° C., and the structure shown in FIG. A sheet type secondary battery was obtained.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0103]
Embodiment 9
A sheet-type secondary battery was manufactured in the same manner as in Example 8, except that the temperature of the cooling step in the heating step-cooling step cycle of the negative electrode 404, the positive electrode 407, and the electrode laminate 409 on which the ion conductor was formed was changed. did.
That is, in this embodiment, in the cooling step in the heating step-cooling step cycle repetition process in the step of forming the ionic conductor on the negative electrode 404 and the positive electrode 407, the temperature of the thermostat is set to 1 ° C. per minute. It was lowered, and when it reached 0 ° C., it was kept at that temperature for 10 minutes. In the cooling step in the heating step-cooling step cycle repetition process for the electrode laminate 409, the temperature of the electrode laminate was lowered at a rate of 1 ° C. per minute, and when the temperature reached 15 ° C., the temperature was kept at that temperature for 10 minutes. .
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0104]
Embodiment 10
A sheet-type secondary battery was manufactured in the same manner as in Example 8, except that the temperature of the cooling step in the heating step-cooling step cycle repetition treatment for the electrode laminate 409 was changed.
That is, in the present embodiment, in the cooling process in the heating process-cooling process cycle repetition process for the electrode laminate 409, the temperature of the electrode laminate is lowered at a rate of 1 ° C. per minute, and when the temperature reaches 15 ° C. For 10 minutes.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0105]
Embodiment 11
A sheet-type secondary battery was produced in the same manner as in Example 8, except that the number of times of the pressure reduction treatment (decompression 10 minutes → normal pressure 10 minutes) of the electrode laminate 409 was changed to one.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0106]
Embodiment 12
A sheet-type secondary battery was fabricated in the same manner as in Example 8, except that the negative electrode 404, the positive electrode 407, and the electrode laminate 409 on which the ionic conductor was formed were repeatedly subjected to three heating step-cooling cycle cycles. did.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0107]
Embodiment 13
A sheet-type secondary battery was manufactured in the same manner as in Example 8, except for the changes described below.
(1) Preparation of ion conductor film:
As in Example 8-3, after measuring the temperature at which the first monomer exhibits orientation, a polymer precursor (L1) is prepared, and the polymer precursor (L1) is impregnated into a porous polyethylene film. After sandwiching two quartz plates with a fluororesin layer formed on one side so that the resin-formed surfaces face each other, a reduced-pressure atmosphere is applied, and air bubbles introduced between the porous film and the quartz plate are removed and the pressure is returned to normal pressure. And placed in a thermostat set at −20 ° C. to orient the monomers in the precursor, and then 10 mW / cm²Was irradiated for 1 hour to carry out a polymerization reaction and a crosslinking reaction, and then the temperature of the thermostat was set to 25 ° C. Thereafter, the temperature of the constant temperature bath is increased at a rate of 1 ° C. per minute, and when the temperature reaches 40 ° C., a heating step of keeping the temperature for 10 minutes is performed. Then, the temperature of the constant temperature bath is decreased at a rate of 1 ° C. per minute. When the temperature reached −20 ° C., a cycle of performing a cooling step of keeping the temperature at that temperature for 10 minutes was defined as one cycle. After repeating this cycle five times, the temperature of the thermostat was set to 25 ° C., and two quartz plates were removed. It was removed to obtain an ion conductor film.
(2) Secondary battery assembly:
The assembling operation of the secondary battery was performed in an argon gas atmosphere.
A polymer precursor (H1) was applied to the surfaces of the negative electrode 404 and the positive electrode 407 on which the ion conductor obtained in Example 8-3 was formed, and the ion conductor formed on the surfaces of the negative electrode 404 and the positive electrode 407 The negative electrode 404 and the positive electrode 407 were adhered to the ion conductor film obtained in the above (1) so that the electrodes faced each other, whereby an electrode laminate 409 was obtained. After reducing the pressure of the electrode laminate to 5.3 kPa for 10 minutes, the pressure was returned to normal pressure and maintained for 10 minutes. The same operation (reduced pressure for 10 minutes → normal pressure for 10 minutes) was repeated twice, followed by sealing with a moisture-proof film that was a laminate film of polypropylene / aluminum foil / polyethylene terephthalate. Thereafter, the mixture was heated to 60 ° C. to perform a polymerization reaction for 3 hours. Next, in the same manner as in (1) above, the electrode laminate 409 is repeatedly subjected to five heating-cooling cycle cycles, and then the temperature of the electrode laminate 409 is set to 25 ° C. I got a battery.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0108]
Embodiment 14
In Example 8, an alkyl group was used instead of the monomer having a polyether group (the number of ethylene oxide, the number of propylene oxide = 20) as the first monomer of the polymer precursor (L1) and the polymer precursor (H1) in the side chain. Same as Example 8 except that a polymer precursor (L2) and a polymer precursor (H2) using a monomer having (carbon number = 18) and a polyether group (ethylene oxide number = 30) in a side chain were used. I went to. The temperature at which the first monomer exhibited orientation was 46 ° C. The polymer precursor (L2) instead of the polymer precursor (L1) has 154 parts of n-octadecyl polyethylene glycol (ethylene oxide number = 30) acrylate having an alkyl group having 18 carbon atoms as a first monomer, 10 parts of polyethylene glycol (ethylene oxide number = 3) methyl methacrylate, 10 parts of methoxytripropylene glycol acrylate, 19 parts of poly (ethylene glycol tetramethylene glycol dimethacrylate) as a crosslinking agent, and 2,2-dimethoxy as a photopolymerization initiator 1 part of 2-phenylacetophenone and 2 mol / dm 2 of lithium tetrafluoroborate dissolved in a mixture of ethylene carbonate and γ-butyl lactone in a volume ratio of 3: 7.³Was added to obtain a polymer precursor (L2).
The polymer precursor (H2) instead of the polymer precursor (H1) is azobis which is a thermal polymerization initiator instead of 1 part of the photopolymerization initiator 2,2-dimethoxy-2-phenylacetophenone of the polymer precursor (L2). A polymer precursor (H1) was prepared using 1 part of isobutyronitrile.
When the secondary battery obtained in this example was evaluated by a capacity test and a cycle life charge / discharge test, it was found that a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0109]
Embodiment 15
In this example, a negative electrode, a positive electrode, and an ion conductor film were produced, a polymer precursor was applied to both surfaces of the negative electrode and the positive electrode, and the negative electrode and the positive electrode were attached to both surfaces of the ion conductor film so as to face each other. Then, after sealing with a moisture-proof film which is a laminate film of polypropylene / aluminum foil / polyethylene terephthalate, the polymer precursor was polymerized. Furthermore, a process of heating and then cooling was repeated several times to produce a sheet type secondary battery. The procedure for manufacturing the sheet type secondary battery will be described below with reference to FIG.
[0110]
(1) The production of the negative electrode 404 and the positive electrode 407 and the formation of the ion conductor on these electrodes were performed in the same manner as in Example 8.
(2) An ion conductor film was produced in the same manner as in Example 12.
(3) Secondary battery assembly
The assembling operation of the secondary battery was performed in an argon gas atmosphere.
The polymer precursor (H1) is applied to the active material surfaces of the negative electrode 404 and the positive electrode 407 on which the ion conductor obtained in the above (1) is formed, so that the application surfaces of the polymer precursor (H1) face each other. The ion conductor film obtained in the above (2) was laminated to the negative electrode 404 and the positive electrode 407 to obtain an electrode laminate 409. The electrode laminate was placed in a reduced-pressure atmosphere for 10 minutes, then returned to normal pressure and maintained for 10 minutes. After repeating the same operation (reduced pressure for 10 minutes → normal pressure for 10 minutes) twice, the electrode laminate was sealed with a moisture-proof film which was a laminate film of polypropylene / aluminum foil / polyethylene terephthalate. Thereafter, the mixture was heated to 60 ° C. to perform a polymerization reaction for 3 hours. Next, in the same manner as in Example 8-3, the electrode laminate 409 was repeatedly subjected to five heating-cooling cycle cycles, and then the temperature of the electrode laminate 409 was set to 25 ° C., and FIG. A sheet-type secondary battery having the configuration shown was obtained.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0111]
Embodiment 16
The same operations as in Example 8 were performed except for the changes described below.
(1) Formation of ion conductor on electrode surface
After applying the polymer precursor (L1) obtained in Example 8 to the active material side of the negative electrode 404 prepared in Example 8-1, a quartz plate having a fluororesin layer formed on one surface is opposed to the active material of the negative electrode 404. Then, the pressure was reduced to 5.3 kPa for 10 minutes and then returned to normal pressure. After placing the polymerization vessel in a thermostat set at −20 ° C. to orient the monomers, 10 mW / cm²Was irradiated for 1 hour to cause a polymerization reaction and a crosslinking reaction, and then the temperature of the constant temperature bath was set to 25 ° C. Thereafter, the temperature of the constant temperature bath is increased at a rate of 1 ° C. per minute, and when the temperature reaches 40 ° C., a heating step of keeping the temperature for 10 minutes is performed. Then, the temperature of the constant temperature bath is decreased at a rate of 1 ° C. per minute. When the temperature reached −20 ° C., a cycle of performing a cooling step of keeping the temperature at that temperature for 10 minutes was defined as one cycle, and after repeating this cycle five times, the temperature of the thermostat was set to 25 ° C. Thus, an ion conductor was formed on the negative electrode 404.
In the same manner as described above, an ion conductor was also formed on the positive electrode 407 prepared in Example 8-2.
(2) Secondary battery assembly
The assembling operation of the secondary battery was performed in an argon gas atmosphere.
The polymer precursor (H1) is applied to the surface of the ion conductor of the negative electrode 404 and the positive electrode 407 on which the ion conductor obtained in the above (2) is formed, and the ion conductor formed on the surface of the negative electrode 404 and the positive electrode 407 is The negative electrode 404 and the positive electrode 407 were attached to the ion conductor film produced in the same manner as in Example 12 so as to face each other, and an electrode laminate 409 was obtained. The electrode laminate was placed in a reduced-pressure atmosphere for 10 minutes, then returned to normal pressure and maintained for 10 minutes. The same operation (reduced pressure for 10 minutes → normal pressure for 10 minutes) was repeated twice, followed by sealing with a moisture-proof film that was a laminate film of polypropylene / aluminum foil / polyethylene terephthalate. Thereafter, the mixture was heated to 60 ° C. to perform a polymerization reaction for 3 hours. Next, in the same manner as in the above (1), the electrode laminate 409 is repeatedly subjected to five heating-cooling cycle cycles, and then the temperature of the electrode laminate 409 is set to 25 ° C. I got a battery.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0112]
Embodiment 17
A sheet-type secondary battery was manufactured in the same manner as in Example 8, except that the heating step and the cooling step cycle were not repeated for the negative electrode 404, the positive electrode 407, and the electrode laminate 409 on which the ion conductor was formed.
The obtained secondary battery was evaluated by a capacity test and a cycle life charge / discharge test. As a result, a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0113]
Embodiment 18
The methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate (ethylene oxide) monomer having a polyether group in the side chain used as the first monomer of the polymer precursors (L1) and (H1) in Example 8 Number, propylene oxide number = 20), and the same as Example 8 except that methoxy-icosaethyleneoxy-block-icosapropyleneoxy-acrylate having ethylene oxide number = 11 and propylene oxide number = 27 was used instead of propylene oxide number = 20). I went to. The temperature at which the first monomer exhibited orientation was 25 ° C. When the secondary battery obtained in this example was evaluated by a capacity test and a cycle life charge / discharge test, it was found that a higher capacity and a better cycle life were obtained as compared with the comparative example. The results are shown in Table 2.
[0114]
[Comparative Example 4]
A sheet-type secondary battery was manufactured in the same manner as in Example 8, except that the temperature of the thermostat was kept at 25 ° C. when forming the ion conductor on the negative electrode 404 and the positive electrode 407.
The obtained secondary battery was evaluated by a capacity test and a charge / discharge test of cycle life, and the results are shown in Table 2.
[0115]
[Comparative Example 5]
In Example 8, the following polymer precursors (L3) and (H3) were used in place of the polymer precursors (L1) and (H1), and the temperature during polymerization was kept at 25 ° C. A sheet-type secondary battery was manufactured in the same manner as in Example 8, except that the heating-cooling cycle cycle was not repeated.
Polymer precursor (L3):
6.1 parts of acrylic acid as a monomer, 1.8 parts of poly (ethylene glycol tetramethylene glycol dimethacrylate) as a crosslinking agent, and 0.025 part of 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator were mixed. 2 mol / dm of lithium fluoroborate dissolved in a solution of ethylene carbonate and γ-butyl lactone mixed in a volume ratio of 3: 7³Was prepared by adding 150.6 parts of an electrolytic solution of The temperature at which acrylic acid as the first monomer exhibited orientation was measured. Although the melting point measured by differential thermal analysis (DSC) was around 13 ° C., when the temperature was changed in the range of −20 ° C. to 20 ° C., and the orientation was observed under crossed Nicols polarization, the dark field was observed at any temperature. And did not show any orientation.
Polymer precursor (H3):
Polymer precursor (H3) using 1 part of azobisisobutyronitrile, which is a thermal polymerization initiator, instead of 1 part of photopolymerization initiator 2,2-dimethoxy-2-phenylacetophenone of polymer precursor (L3) Was prepared.
The obtained secondary battery was evaluated by a capacity test and a charge / discharge test of cycle life, and the results are shown in Table 2.
[0116]
[Comparative Example 6]
Using an electrolytic solution instead of the ionic conductor, a sheet-type battery was manufactured by the following method, and then a charge / discharge test of the obtained battery was performed. The results are shown in Table 2 below.
(1) The negative electrode 404 and the positive electrode 407 were produced in the same manner as in Example 8.
(2) Secondary battery assembly
A negative electrode 404 and a positive electrode 407 were attached to both sides of a polyethylene porous film so as to face each other, and 2 mol / mol of lithium tetrafluoroborate was dissolved in a solution in which ethylene carbonate and γ-butyl lactone were mixed at a volume ratio of 3: 7. dm³And then sealed with a moisture-proof film, which is a laminate film of polypropylene / aluminum foil / polyethylene terephthalate, to produce a sheet-shaped battery.
The obtained secondary battery was evaluated by a capacity test and a charge / discharge test of cycle life, and the results are shown in Table 2.
[0117]
[Table 2]

[0118]
【The invention's effect】
According to the present invention, by increasing the orientation of the polymer skeleton of the ionic conductor, it is possible to produce the ionic conductor with a high ionic conductivity and excellent mechanical strength which can be produced by a simple method at a low cost and a high capacity. A secondary battery having good performance of cycle life can be achieved.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a polymer structure of an ion conductor of the present invention.
FIG. 2 shows a flowchart of an example of a method for manufacturing an ion conductor of the present invention.
FIG. 3 is a diagram obtained by measuring the melting point of a first monomer used in the present invention by differential thermal analysis (DSC).
FIG. 4 is a view schematically showing a configuration of an example of a manufacturing apparatus used in the method for manufacturing an ion conductor of the present invention.
FIG. 5 is a schematic sectional view schematically showing a configuration of an example of a single-layer sheet type secondary battery.
FIG. 6 is a schematic cross-sectional view schematically illustrating a configuration of an example of a single-layer flat (coin-shaped) secondary battery.
FIG. 7 is a diagram obtained by measuring the orientation of a film-like ion conductor produced in Example 1 by small-angle X-ray scattering.
FIG. 8 is a schematic view of a device for measuring ion conductivity of an ion conductor.
[Explanation of symbols]
101 Main chain
102 Side chain
103 Crosslinking
104 Ion conduction pathway
105 polyether group
301 polymerization vessel
302 temperature controller,
303 Light energy irradiation device
401 Ion conductor
402 Negative electrode current collector
403 Negative electrode active material (negative electrode material)
404 negative electrode
405 Positive electrode active material (positive electrode material)
406 positive electrode current collector
407 positive electrode
408 Exterior material
409 electrode laminate
501 Negative electrode
502 Ion conductor
503 positive electrode
504 negative electrode can (negative electrode terminal)
505 Positive electrode can (positive electrode terminal)
506 gasket

Claims (17)

A method for producing an ionic conductor having mainly an at least one polymer compound and at least one electrolyte and having anisotropy in ionic conductivity, comprising at least one monomer and at least one electrolyte. Having a polymerization step of forming an ion conductor by a polymerization reaction of a polymer precursor containing, in the polymerization step, the polymer precursor during the polymerization reaction, the monomer in the precursor shows orientation A method for producing an ionic conductor, comprising keeping the temperature below the temperature. In the polymerization step, a step (b) of heating the formed ion conductor to a temperature at which the monomer exhibits orientation is performed, and then the ion conductor is cooled to a temperature at which the monomer exhibits orientation. 3. The method for producing an ionic conductor according to claim 1, further comprising a step of subjecting a cycle of performing the step (b) of repeating at least once to a step of performing the step (b). In the polymerization step, the polymer precursor is coated on a substrate having planarity, and then the polymer precursor is kept at a temperature equal to or lower than the temperature at which the monomer exhibits orientation. The method for producing an ionic conductor according to claim 1, further comprising a step of irradiating the ionic conductor with energy rays. The ion conductor according to claim 3, wherein the irradiation with the energy ray is performed through an energy ray transmitting member arranged so as to maintain a constant distance to the base material and to be in contact with the applied polymer precursor. Production method. The method according to claim 3, wherein the base material is a positive electrode in which a positive electrode material is provided on a positive electrode current collector or a negative electrode in which a negative electrode material is provided on a negative electrode current collector. The method for producing an ion conductor according to any one of claims 1 to 5, wherein the ion conductor is composed of a polymer chain containing at least a segment represented by the following general formula (1).
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General formula (1)

(Wherein, R1 and R2 are each a hydrogen atom or an alkyl group having 2 or less carbon atoms, A and B are each a group containing at least a polyether, and R3 is an alkyl group having at least 1 to 4 carbon atoms. Is a group having One of A and B in the general formula (1) is-(C
7. The ion according to claim 6, wherein H ₂ —CH ₂ —O) _m — and the other is — (CH ₂ —CH (CH ₃ ) —O) _n — (m, n is an integer of 1 to 30). Manufacturing method of conductor. The method for producing an ionic conductor according to claim 7, wherein m and n are m / n = 0.5 to 2. The method for producing an ion conductor according to any one of claims 1 to 5, wherein the ion conductor is composed of a polymer chain containing at least a segment represented by the following general formula (2). .
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General formula (2)

(Wherein, R4 and R5 are each a hydrogen atom or an alkyl group having 2 or less carbon atoms, and X is a group containing — (CH ₂ —CH ₂ —O) _k — (k is an integer of 1 to 40). R6 is at least a linear alkyl group having 6 to 22 carbon atoms or an alkylbenzyl group having a linear alkyl group having 6 to 22 carbon atoms.) A method for manufacturing a secondary battery having a configuration in which an ion conductor is disposed between a positive electrode and a negative electrode provided to face each other, wherein the ion conductor is manufactured by the method according to any one of claims 1 to 9. A method for manufacturing a secondary battery, comprising the steps of: A method for manufacturing a secondary battery having a configuration in which an ion conductor is disposed between a positive electrode and a negative electrode provided to face each other,
(1) applying a first polymer precursor containing at least one type of monomer and at least one type of electrolyte to the surface of the positive electrode or / and the negative electrode;
(2) By subjecting the first polymer precursor applied to the surface of the positive electrode and / or the negative electrode to a polymerization reaction while keeping the temperature of the monomer in the precursor below the temperature at which the monomer exhibits orientation. Forming a first ion conductor having anisotropy in ion conductivity,
(3) applying a second polymer precursor containing at least one type of monomer and at least one type of electrolyte to the surface of the ion conductor;
(4) laminating the positive electrode and the negative electrode such that the first ionic conductor having the applied second polymer precursor is located between the positive electrode and the negative electrode; and (5) the laminating. The second polymer precursor located between the positive electrode and the negative electrode with the first ion conductor interposed therebetween is subjected to a polymerization reaction while keeping the temperature of the monomer in the precursor below the temperature at which the monomer exhibits orientation. Forming a second ion conductor by attaching the first ion conductor to the interface of the first ion conductor formed on the surface of the positive electrode or the negative electrode and the negative electrode or the positive electrode on which the first ion conductor is not formed. (1) a step of bringing the interface or the interface of the first ion conductor formed on the surface of the negative electrode or the positive electrode into contact with the second ion conductor formed later with adhesion. Or (5) Sequential method of manufacturing a secondary battery and performing. The production of the first ion conductor and the second ion conductor is performed according to the method described in claims 1 to 4, and the first ion conductor and the second ion conductor are claimed in claim 6. The method for manufacturing a secondary battery according to claim 11, which is described in any one of (1) to (9). The production of the first ion conductor and the second ion conductor is performed according to the method described in claims 1 to 4, and the first ion conductor and the second ion conductor are claimed in claim 6. The method for manufacturing a secondary battery according to claim 11, which is described in any one of (1) to (9). A method for manufacturing a secondary battery having a configuration in which an ionic conductor is disposed between a positive electrode and a negative electrode provided to face each other,
(1) subjecting a first polymer precursor containing at least one kind of monomer and at least one kind of electrolyte to a polymerization reaction while maintaining the temperature of the first polymer precursor in the precursor at a temperature equal to or lower than a temperature at which the monomer exhibits orientation. Forming a first ion conductor having anisotropy in ion conductivity by
(2) A second polymer precursor containing at least one monomer and at least one electrolyte is coated on both surfaces of the first ion conductor or at least one surface of the positive electrode and / or the negative electrode. Attaching process,
(3) a step of bonding the first ion conductor so as to be located between the positive electrode and the negative electrode; and (4) a step of bonding the second polymer precursor to the second polymer precursor so that the monomer in the precursor has an orientation. A second ion conductor having anisotropy in ionic conductivity is formed by subjecting to a polymerization reaction while keeping the temperature at or below the temperature indicating the interface between the positive electrode and the first ionic conductor and the negative electrode. (1) to (4), in which an interface between the first ion conductor and the second ion conductor formed later is brought into contact with an adhesive property. Manufacturing method of a secondary battery. The production of the first ion conductor and the second ion conductor is performed according to the method described in claims 1 to 4, and the first ion conductor and the second ion conductor are claimed in claim 6. The method for manufacturing a secondary battery according to claim 14, wherein At least one surface of the positive electrode or the negative electrode is coated with the polymer precursor, and the monomer has anisotropy in ion conductivity due to a polymerization reaction of the polymer precursor while keeping the temperature at or below a temperature at which the monomer exhibits orientation. The method for manufacturing a secondary battery according to claim 11, further comprising a step of forming an ion conductor. A heating step in which the monomer contained in the polymer precursor in the secondary battery is heated to a temperature equal to or higher than the temperature indicating the orientation of the secondary battery prepared through the process according to claim 11 or 13, The method for manufacturing a secondary battery according to claim 11, further comprising a step of performing a process of repeating a cycle of performing a cooling step of cooling the temperature to be lower than the temperature as one cycle twice or more.

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