JP3685296B2 - Electrode for lithium secondary battery, polarizable electrode for electric double layer capacitor, and binder for these electrodes - Google Patents

Description

【００１０】
［式中の記号は後記と同じ意味を表わす。］
で示される重合性官能基を有し、ポリまたはオリゴカーボネート基を主成分とする重合性化合物が硬化性が良好で、容易に架橋できることから、各種電極活物質粉体との混合が容易で耐熱性に優れた電極用結着剤であることを見出した。
さらに上記電極用結着剤から得られる電極を用いた電池や電気二重層コンデンサは高エネルギー密度で、取り出し電流が大きく、耐久性、信頼性に優れていることを見出した。
【００１１】
以上の知見に基づいて本発明者らは、以下の(1)電極用結着剤、(2)その電極用結着剤から得られる電極とその製造方法、並びに(3)その電極を用いた電池、電 気二重層コンデンサを提供する。
【００１２】
［１］下記一般式（２）及び／または一般式（３）
【化３】

［式中、Ｒ²及びＲ³は、水素原子または炭素数１〜６のアルキル基を表わし、Ｒ⁴は炭素数１〜１０の鎖状、分岐状及び／または環状の、ヘテロ原子を含んでいてもよい２価の基を表わし、ｘは０または１〜１０の整数である。但し、同一分子中に複数存在するＲ²、Ｒ³、Ｒ⁴及びｘは、それぞれ同一でもよいし異なってもよい。］
で示される重合性官能基を有し、一般式（１）
【化４】

［式中、Ｒ¹は炭素数が１〜１０の鎖状、分岐状及び／または環状の、ヘテロ原子を含んでいてもよい２価の基を表わし、ｍは１〜１０の整数であり、ｎは２〜1000の整数である。但し、同一分子中に複数存在するＲ¹、ｍ及びｎは、それぞれ同一でもよいし異なってもよい。］
で示されるポリまたはオリゴカーボネート基を主成分とする少なくとも一種の熱及び／または活性光線重合性化合物からなる、リチウム二次電池用電極または電気二重層コンデンサ用分極性電極に用いる結着剤。
［２］リチウム合金、炭素材料、無機酸化物、無機硫化物及び電導性高分子化合物から選ばれる少なくとも一つのリチウム二次電池用電極材料と、前記１に記載の結着剤の重合物とを含むリチウム二次電池用電極。
［３］炭素材料、無機酸化物、無機硫化物、無機ハロゲン化物及び金属から選ばれる少なくとも一種の分極性電極材料と、前記１に記載の結着剤の重合物とを含む電気二重層コンデンサ用分極性電極。
［４］前記２に記載の電極を用いることを特徴とするリチウム二次電池。
［５］イオン伝導性物質を介して分極性電極を配置した電気二重層コンデンサにおいて、前記３に記載の分極性電極を用いることを特徴とする電気二重層コンデンサ。
［６］前記１に記載の重合性化合物と電極材料粉体とを混合し、あるいはさらに少なくとも一種の有機溶媒を添加した後、混合物を成形し、該重合性化合物を重合することを特徴とするリチウム二次電池または電気二重層コンデンサに用いる電極の製造方法。
【００１６】
【発明の実施の態様】
以下に本発明を詳細に説明する。
［電極用結着剤］
本発明の電極用結着剤に用いる高分子化合物は電極活物質や集電体と接着性が良好で、弾性があり、電気化学的安定性や耐電解液性、耐熱性が良好であり、各種有機極性溶媒を吸液、保持できるものであり、下記一般式（１）で示されるポリまたはオリゴカーボネート構造を有する架橋及び／または側鎖基を含むものである。
【００１７】
【化１２】

式中、Ｒ¹は炭素数が１〜１０の鎖状、分岐状及び／または環状の、ヘテロ原 子を含んでいてもよい２価の基を表わし、ｍは１〜１０の整数であり、ｎは２〜1000の整数である。
【００１８】
上記一般式（１）でｍが１０を越えると、高分子化合物中のカーボネート基が少なくなり、耐熱性が低下し、また誘電率が低下し各種極性溶媒と相溶性が低下するため好ましくない。好ましいｍは１〜５である。
上記一般式でのＲ¹の炭素数が多すぎると、高分子化合物中のカーボネート基 が少なくなり、同様に耐熱性が低下し好ましくない。また、高分子化合物の疎水性が増加し、各種極性溶媒との相溶性が低下し、好ましくない。好ましいＲ¹の 炭素数は１〜４である。
本発明の電極用結着剤に用いられる高分子中の一般式（１）で示されるポリまたはオリゴカーボネート基の繰り返し数ｎは２〜1000の範囲であり、３〜１００の範囲が好ましく、特に５〜５０が好ましい。
【００１９】
本発明の高分子固体電解質に用いられる高分子としては、一般式（１）で示されるポリまたはオリゴカーボネート基を有し、かつ下記一般式（２）及び／または（３）で示される重合性官能基
【化１３】

［式中、Ｒ²及びＲ³は、水素原子または炭素数１〜６のアルキル基を表わし、Ｒ⁴は炭素数１〜１０の鎖状、分岐状及び／または環状の、ヘテロ原子を含んでい てもよい２価の基を表わし、ｘは０または１〜１０の整数である。但し、同一分子中に複数存在するＲ²、Ｒ³、Ｒ⁴及びｘは、それぞれ同一でもよいし異なって もよい。］を有する少なくとも一種の熱及び／または活性光線重合性化合物（以下、単に「重合性化合物」と略す。）の重合体が、各種電気化学素子に用いられる電極との複合が容易であり、また耐熱性も向上するので好ましい。
【００２０】
具体的な重合性化合物としては、例えば以下の一般式（４）あるいは（５）で示される化合物が挙げられる。
【化１４】

【化１５】

式中、Ｒ⁵は炭素数１〜２０の鎖状、分岐状及び／または環状の、ヘテロ原子 を含んでいてもよい基を表わし、その他の記号は前記と同じ意味を表わす。
【００２１】
一般式（１）で示される基と一般式（２）で示される基とを有する重合性化合物を合成する方法に特に制限はないが、例えば、酸クロライドと末端にヒドロキシル基を有するポリまたはオリゴカーボネートオールとを以下の工程で反応させることにより容易に得られる。
【００２２】
【化１６】

式中、Ｒ¹、ｍ、ｎ及びＲ²は前記と同じ意味を表わす。
【００２３】
一般式（１）で示される基と一般式（３）で示される基とを有する重合性化合物を合成する方法に特に制限はないが、例えば、
【化１７】

で示されるイソシアネート化合物と末端にヒドロキシル基を有するポリまたはオリゴカーボネートオールとを反応させることにより容易に得ることができる。
【００２４】
具体的方法として、一般式（３）で示される官能基を一つ有する化合物は、例えば、メタクリロイルイソシアナート系化合物（以下、ＭＩ類と略記する。）あるいはアクリロイルイソシアナート系化合物（以下、ＡＩ類と略記する。）とモノアルキルポリまたはオリゴカーボネートオールとを、以下の反応の様に１：１のモル比で反応させることにより容易に得ることができる。
【００２５】
【化１８】

式中、Ｒ⁶は炭素数１〜１０の有機基を表わし、Ｒ¹、ｍ、ｎ、Ｒ³、Ｒ⁴及びｘは前記と同じ意味を表わす。
【００２６】
また、一般式（３）で示される官能基を二つ有する化合物は、例えば、ＭＩ類あるいはＡＩ類とポリまたはオリゴカーボネートジオールとを以下のように２：１のモル比で反応させることにより容易に得られる。
【００２７】
【化１９】

式中、Ｒ¹、ｍ、ｎ、Ｒ³、Ｒ⁴及びｘは前記と同じ意味を表わす。
また一般式（３）で示される官能基を三つ有する化合物は、例えば、ＭＩ類あるいはＡＩ類とポリまたはオリゴカーボネートトリオールとを３：１のモル比で反応させることにより容易に得られる。
【００２８】
ここで一般式（２）あるいは（３）で示される官能基を１つしか有さない化合物を重合してできる高分子は、架橋構造を有しておらず、弾性が低く、耐熱性も低い。従って、一般式（２）あるいは（３）で示される官能基を２つ以上有する重合性化合物と共重合し、架橋させるか、一般式（２）あるいは（３）で示される官能基を２つ以上有する重合性化合物から得られる高分子と併用することが好ましい。
【００２９】
また前記一般式（３）で示される重合性官能基を有する化合物を重合して得られる高分子化合物は、ウレタン基を含んでおり、誘電率が高くなり、各種溶媒との相溶性が高くなり、好ましい。さらに一般式（３）で示される重合性官能基を有する化合物は重合性が良好で、各種電極と複合後の硬化が容易であり好ましい。
【００３０】
本発明の電極用結着剤の構成成分として好ましい高分子化合物は、前記重合性化合物の単独重合体であっても、同一カテゴリーに属する２種以上の共重合体であっても、あるいは前記重合性化合物の少なくとも一種と他の重合性化合物との共重合体であってもよい。
【００３１】
前記重合性化合物と共重合可能な他の重合性化合物としては、特に制限はないが、例えば、メタクリル酸メチル、アクリル酸ｎ−ブチル等の（メタ）アクリル酸アルキルエステル、各種ウレタン（メタ）アクリレート、オキシアルキレン及び／またはオキシフルオロカーボン鎖を有する（メタ）アクリル酸エステル及び／またはウレタン（メタ）アクリレート、（メタ）アクリル酸フッ素化アルキルエステル、アクリルアミド、メタクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ，Ｎ−ジメチルメタクリルアミド、炭酸ビニレン、（メタ）アクリロイルカーボネート、Ｎ−ビニルピロリドン、アクリロイルモルホリン、メタクリロイルモルホリン、Ｎ，Ｎ−ジメチルアミノプロピル（メタ）アクリルアミド等の（メタ）アクリルアミド系化合物、スチレン、α−メチルスチレン等のスチレン系化合物、Ｎ−ビニルアセトアミド、Ｎ−ビニルホルムアミド等のＮ−ビニルアミド系化合物、エチルビニルエーテル等のアルキルビニルエーテルを挙げることができる。
【００３２】
これらの中で、好ましくは（メタ）アクリル酸エステル、ウレタン（メタ）アクリレート、またはオキシアルキレン及び／またはオキシフルオロカーボン鎖を有する（メタ）アクリル酸エステル及び／またはウレタン（メタ）アクリレートが用いられる。これらの中で、ウレタン（メタ）アクリレートが重合性という観点で特に好ましい。
【００３３】
また、本発明の電極用結着剤に用いる高分子化合物としては、前記重合性化合物の少なくとも一種から得られる重合体及び／または前記重合性化合物を共重合成分とする共重合体と、他の高分子化合物との混合物であってもよい。混合する他の高分子化合物としては、例えば、ポリエチレンオキサイド、ポリプロピレンオキサイド、ポリアクリロニトリル、ポリブタジエン、ポリメタクリル（またはアクリル）酸エステル類、ポリスチレン、ポリホスファゼン類、ポリシロキサンあるいはポリシラン、ポリフッ化ビニリデン、ポリテトラフルオロエチレン等のポリマーが挙げられる。
【００３４】
前記一般式（１）で示されるポリまたはオリゴカーボネート基を有する高分子由来の構造単位の量は、前記重合性化合物を単独重合するか、その他の共重合成分と共重合するか、さらに他の高分子化合物を混合するかにより、あるいはそれらの種類により異なるため、一概にはいえないが、電極用結着剤に用いたときの接着性、電気化学的安定性、耐熱性、電解液との相溶性を考慮すると、高分子成分全量に対し５０重量％以上含有することが好ましく、さらには７０重量％以上含有することが好ましい。
【００３５】
前記重合性化合物の重合は、官能基であるアクリロイル基もしくはメタクリロイル基の重合性を利用した一般的な方法により行なうことができる。すなわち、前記重合性化合物単独、あるいは重合性化合物と他の前記共重合可能な重合性化合物の混合物に、アゾビスイソブチロニトリル、ベンゾイルパーオキサイド等の加熱ラジカル重合触媒、ベンジルメチルケタール等の活性光線ラジカル重合触媒ＣＦ₃ＣＯＯＨ等のプロトン酸、ＢＦ₃、ＡｌＣｌ₃等のルイス酸等のカチオン重 合触媒、あるいはブチルリチウム、ナトリウムナフタレン、リチウムアルコキシド等のアニオン重合触媒を用いて、ラジカル重合、カチオン重合あるいはアニオン重合させることができる。
【００３６】
重合させる温度としては、前記重合性化合物の種類によるが、重合が起こる温度であれば良く、通常は、０℃から２００℃の範囲で行なえばよい。
活性光線照射により重合させる場合には、前記重合性化合物の種類によるが、例えば、ベンジルメチルケタール、ベンゾフェノン等の開始剤を使用して、数ｍＷ以上の紫外光またはγ線、電子線等を照射して重合させることができる。
【００３７】
［電極及びその製造方法］
本発明の電極は各種電気化学素子に用いる電極材料粉体を本発明の電極用結着剤で結着し成形したものである。
本発明の電池用電極の正極材料としては、金属酸化物、金属硫化物、導電性高分子あるいは炭素材料のような高酸化還元電位の電極活物質（正極活物質）を用いることにより、高電圧、高容量の電池が得られるので好ましい。このような正極活物質の中では、充填密度が高く体積容量密度が高くなるという点で、酸化コバルト、酸化マンガン、酸化バナジウム、酸化ニッケル、酸化モリブデン等の金属酸化物、硫化モリブデン、硫化チタン、硫化バナジウム等の金属硫化物が好ましく、特に酸化マンガン、酸化ニッケル、酸化コバルト等が高容量、高電圧という点から好ましい。この場合の金属酸化物や金属硫化物を製造する方法は特に限定されず、例えば、電気化学，第２２巻，５７４頁（1954年）に記載されているような、一般的な電解法や加熱法によって製造される。また、これらを電極活物質としてリチウム電池に使用する場合、電池の製造時に、例えば、Ｌｉ_xＣｏＯ₂やＬｉ_xＭｎＯ₂等の形でリチウム元素を金属酸化物あるいは金属硫化物に挿入（複合）した状態で用いることが好ましい。リチウム元素を挿入する方法は特に限定されず、例えば、電気化学的にリチウムイオンを挿入する方法や、米国特許第4357215号に記載されているように、Ｌｉ₂ＣＯ₃の塩と金属酸化物を混合、加熱 処理することによって実施できる。
【００３８】
また柔軟で、薄膜化しやすいという点では、導電性高分子が正極活物質として好ましい。導電性高分子の例としては、ポリアニリン、ポリアセチレン及びその誘導体、ポリパラフェニレン及びその誘導体、ポリピロール及びその誘導体、ポリチエニレン及びその誘導体、ポリピリジンジイル及びその誘導体、ポリイソチアナフテニレン及びその誘導体、ポリフリレン及びその誘導体、ポリセレノフェン及びその誘導体、ポリパラフェニレンビニレン、ポリチエニレンビニレン、ポリフリレンビニレン、ポリナフテニレンビニレン、ポリセレノフェンビニレン、ポリピリジンジイルビニレン等のポリアリーレンビニレン及びそれらの誘導体等が挙げられる。これら導電性高分子は、一般的な化学的あるいは電気化学的酸化重合方法、あるいはその他の公知の方法に従って製造される。
また、炭素材料としては、天然黒鉛、人造黒鉛、気相法黒鉛、石油コークス、石炭コークス、フッ化黒鉛、ピッチ系炭素、ポリアセン等が挙げられる。
【００３９】
本発明の電池用電極の負極活物質としては、アルカリ金属、アルカリ金属合金、炭素材料、金属酸化物や導電性高分子化合物のようなアルカリ金属イオンをキャリアーとする低酸化還元電位のものを用いることにより、高電圧、高容量の電池が得られるので好ましい。このような負極活物質の中では、リチウム金属あるいはリチウム／アルミニウム合金、リチウム／鉛合金、リチウム／アンチモン合金等のリチウム合金類が最も酸化還元電位が低く、かつ薄膜化が可能である点から特に好ましい。また炭素材料もリチウムイオンを吸蔵した場合、低酸化還元電位となり、しかも安定、安全であるという点で特に好ましい。リチウムイオンを吸蔵放出できる材料としては、天然黒鉛、人造黒鉛、気相法黒鉛、石油コークス、石炭コークス、ピッチ系炭素、ポリアセン、Ｃ６０、Ｃ７０等のフラーレン類等が挙げられられる。
【００４０】
本発明の電気二重層コンデンサ用分極性電極に用いる分極性材料としては、各種炭素材料が挙げられる。炭素材料としては、比表面積が大きければ特に制限はないが、比表面積の大きいほど電気二重層の容量が大きくなり好ましい。例えば、ファーネスブラック、サーマルブラック（アセチレンブラックを含む）、チャンネルブラック等のカーボンブラック類や、椰子がら炭等の活性炭、天然黒鉛、人造黒鉛、気相法で製造したいわゆる熱分解黒鉛、ポリアセン及びＣ６０、Ｃ７０を挙げることができる。これらを水蒸気処理や酸処理等でさらに比表面積を上げたものが好ましい。
【００４１】
これら電極材料を電極に成形する方法としては、本発明のポリまたはオリゴカーボネート基を有する重合性化合物と電極材料粉末とを適当な割合で混合後、あるいはさらにカーボンブラック等の導電助剤や少なくとも一種の溶媒を添加した後、これら混合物を塗布及びまたは成形し、さらに該重合性化合物を加熱や活性光線照射等で重合することにより電極全体を硬化させる方法が推奨される。
【００４２】
溶媒は電極材料粉末と重合性化合物との混合を均一にするためや、その後の塗布成形を容易にするように混合物の粘度を低下させるために使用されることがある。用いる溶媒としては、本発明のポリまたはオリゴカーボネート基を有する重合性化合物や電極材料との相溶性が良好であるものが適している。これら溶媒は電極製造後の乾燥等で除去されることが多いが、電極内に残存した場合には電気化学的安定範囲が広く、用いる電気化学素子に悪影響を及ぼさない化合物が適している。そのような溶媒としては、１，２−ジメトキシエタン、２−メチルテトラヒドロフラン、クラウンエーテル、トリエチレングリコールメチルエーテル、テトラエチレングリコールジメチルエーテル等のエーテル類、エチレンカーボネート、プロピレンカーボネート、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等のカーボネート類、ベンゾニトリル、トルニトリル等の芳香族ニトリル類、ジメチルホルムアミド、ジメチルスルホキシド、Ｎ−メチルピロリドン、Ｎ−ビニルピロリドン、スルホラン等の硫黄化合物、リン酸エステル類等が挙げられる。これらの中で、エーテル類及びカーボネート類が好ましく、カーボネート類が特に好ましい。
【００４３】
［電池の構成］
本発明の電池は電極用結着剤にポリまたはオリゴカーボネート基を有する重合性化合物を用いた電極を使用するものであり、取り出し電流が大きく、あるいは加工性、信頼性に優れるという特徴がある。本発明の電池の一例として、薄膜電池の概略断面図を図１に示す。図中、１は正極、２は高分子固体電解質、３は負極、４ａ，４ｂは集電体、５ａ，５ｂは絶縁性樹脂封止剤である。
【００４４】
特にアルカリ金属イオンをキャリアーとする電池は出力電圧が高く、エネルギー密度が高い。この場合、電解質層の電解質塩としてはアルカリ金属塩を使用する。アルカリ金属塩としては、例えばＬｉＣＦ₃ＳＯ₃、ＬｉＰＦ₆、ＬｉＣｌＯ₄、ＬｉＢＦ₄、ＬｉＳＣＮ、ＬｉＡｓＦ₆、ＬｉＮ（ＣＦ₃ＳＯ₂）₂、ＬｉＮ（Ｃ Ｆ₃ＣＦ₂ＳＯ₂）₂、ＮａＣＦ₃ＳＯ₃、ＬｉＩ、ＮａＰＦ₆、ＮａＣｌＯ₄、ＮａＩ、ＮａＢＦ₄、ＮａＡｓＦ₆、ＫＣＦ₃ＳＯ₃、ＫＰＦ₆、ＫＩ等を挙げることがで きる。
【００４５】
なお、前記電池構成用構造体あるいは前記支持体はＳＵＳ等の金属、ポリプロピレン、ポリイミド等の樹脂、あるいは導電性あるいは絶縁性ガラス等のセラミックス材料であればよいが、特にこれらの材料からなるものに限定されない。また、その形状は筒状、箱状、シート状その他いかなる形状でもよい。
【００４６】
［電気二重層コンデンサの構成］
次に本発明の電気二重層コンデンサについて説明する。
本発明の電気二重層コンデンサは電極用結着剤にポリまたはオリゴカーボネート基を有する重合性化合物を用いた電極を使用するものであり、取り出し電流が大きく、あるいは加工性、信頼性に優れているという特徴がある。
【００４７】
本発明の電気二重層コンデンサの一例の概略断面図を図２に示す。この例は、大きさ１ｃｍ×１ｃｍ、厚み約0.5ｍｍの薄型セルで、７ａ，７ｂは集電体であ り、集電体の内側には一対の分極性電極６ａ，６ｂが配置されており、その間に高分子固体電解質膜８が配置されている。９は絶縁性樹脂封止剤、１０はリード線である。
集電体７ａ，７ｂは電子伝導性で電気化学的に耐食性があり、できるだけ比表面積の大きい材料を用いることが好ましい。例えば、各種金属及びその焼結体、電子伝導性高分子、カーボンシート等を挙げることができる。
【００４８】
本発明の電気二重層コンデンサの場合の電解質層に用いる電解質塩の種類は特に限定されるものではなく、電荷キャリアーとしたいイオンを含んだ化合物を用いればよいが、電解質層中の解離定数が大きく、分極性電極と電気二重層を形成しやすいイオンを含むことが望ましい。このような化合物としては、（ＣＨ₃）₄ＮＢＦ₄、（ＣＨ₃ＣＨ₂）₄ＮＣｌＯ₄等の４級アンモニウム塩、ピリジニウム塩 、ＡｇＣｌＯ₄等の遷移金属塩、（ＣＨ₃）₄ＰＢＦ₄等の４級ホスホニウム塩、ＬｉＣＦ₃ＳＯ₃、ＬｉＰＦ₆、ＬｉＣｌＯ₄、ＬｉＩ、ＬｉＢＦ₄、ＬｉＳＣＮ、Ｌ ｉＡｓＦ₆、ＬｉＮ（ＣＦ₃ＳＯ₂）₂、ＬｉＮ（ＣＦ₃ＣＦ₂ＳＯ₂）₂、ＮａＣＦ₃ ＳＯ₃、ＮａＰＦ₆、ＮａＣｌＯ₄、ＮａＩ、ＮａＢＦ₄、ＮａＡｓＦ₆、ＫＣＦ₃ＳＯ₃、ＫＰＦ₆、ＫＩ等のアルカリ金属塩、パラトルエンスルホン酸等の有機酸及びその塩、塩酸、硫酸等の無機酸等が挙げられる。これらの中で、出力電圧が高く取れ、解離定数が大きいという点から、４級アンモニウム塩、ピリジニウム塩、４級ホスホニウム塩、アルカリ金属塩が好ましい。
【００４９】
なお、前記コンデンサ構成用構造体あるいは前記支持体は、ＳＵＳ等の金属、ポリプロピレン、ポリイミド等の樹脂、あるいは導電性あるいは絶縁性ガラス等のセラミックス材料であればよいが、特にこれらの材料からなるものに限定されるものではなく、また、その形状は、筒状、箱状、シート状その他いかなる形状でもよい。
【００５０】
電気二重層コンデンサの形状としては、図２のようなシート型のほかに、コイン型、あるいは分極性電極及び高分子固体電解質のシート状積層体を円筒状に捲回し、円筒管状のコンデンサ構成用構造体に入れ、封止して製造された円筒型等であっても良い。
【００５１】
【実施例】
以下に本発明について代表的な例を示しさらに具体的に説明する。なお、これらは説明のための単なる例示であって、本発明はこれらに何等制限されるものではない。
【００５２】
実施例１：化合物１、２及び３の合成
【化２０】

上式（ａ）、（ｂ）及び（ｃ）に従い、常法で各種アルキレングリコールに窒素下、１０℃以下で過剰のホスゲンガスを吹き込み、約５時間反応させ、各種アルキレングリコールのビスクロロホルメート体、化合物１、化合物２、化合物３を合成した。これらの同定はＧＣ−ＭＳで行なった。
【００５３】
実施例２：化合物１、２、３のオリゴマー化（化合物４、５、６の合成）
【化２１】

上式（ｄ）、（ｅ）及び（ｆ）に従い、常法で実施例１で合成した各種アルキレングリコールビスクロロホルメート体（化合物１、２、３）と各種アルキレングリコールとを、ピリジン存在下、２５℃以下、ジクロロメタン中で約６時間反応させた後、過剰の水を加え、残クロロホルメート末端を水酸基化し、両末端に水酸基を有するオリゴカーボネート（化合物４、化合物５、化合物６）を合成した。
ＧＰＣ分析により求めた、各オリゴカーボネートの重量平均分子量（Ｍｗ）、繰り返し数ｘ、ｙ、ｚの平均は以下の通りであった。
化合物４ Ｍｗ 〜約 ８００、ｘ：〜約８、
化合物５ Ｍｗ 〜約１５００、ｙ：〜約１０、
化合物６ Ｍｗ 〜約１２００、ｚ：〜約１０。
【００５４】
実施例３：重合性化合物７の合成
【化２２】

化合物４（平均分子量８００）（40.0ｇ）及びＭＯＩ（メタクリロイルオキシエチルイソシアネート）（15.5ｇ）を窒素雰囲気中でよく精製したＴＨＦ（２００ｍｌ）に溶解した後、ジブチルチンジラウレート（0.44ｇ）を添加した。その後、２５℃で約１５時間反応させることにより、無色生成物を得た。その¹Ｈ− ＮＭＲ、ＩＲ及び元素分析の結果から、化合物４とＭＯＩは１対２で反応し、ＭＯＩのイソシアナート基が消失し、ウレタン結合が生成しており、重合性化合物７が生成していることがわかった。
【００５５】
実施例４：重合性化合物８の合成
【化２３】

化合物５（平均分子量1500）（75.0ｇ）及びＭＯＩ（15.5ｇ）を窒素雰囲気中でよく精製したＴＨＦ（２００ｍｌ）に溶解した後、ジブチルチンジラウレート（0.44ｇ）を添加した。その後、２５℃で約１５時間反応させることにより、無色生成物を得た。その¹Ｈ−ＮＭＲ、ＩＲ及び元素分析の結果から、化合物５と ＭＯＩは１対２で反応し、ＭＯＩのイソシアナート基が消失し、ウレタン結合が生成しており、重合性化合物８が生成していることがわかった。
【００５６】
実施例５：重合性化合物９の合成
【化２４】

化合物６（平均分子量1200）（60.0ｇ）及びＭＯＩ（15.5ｇ）を窒素雰囲気中でよく精製したＴＨＦ（２００ｍｌ）に溶解した後、ジブチルチンジラウレート（0.44ｇ）を添加した。その後、２５℃で約１５時間反応させることにより、無色生成物を得た。その¹Ｈ−ＮＭＲ、ＩＲ及び元素分析の結果から、化合物６と ＭＯＩは１対２で反応し、ＭＯＩのイソシアナート基が消失し、ウレタン結合が生成しており、重合性化合物９が生成していることがわかった。
【００５７】
実施例６：コバルト酸リチウム正極の製造
１１ｇのＬｉ₂ＣＯ₃と２４ｇのＣｏ₃Ｏ₄をよく混合し、酸素雰囲気下、８００℃で２４時間加熱後、粉砕することによりＬｉＣｏＯ₂粉末を得た。このＬｉＣ ｏＯ₂粉末とアセチレンブラック、実施例３、４、５で製造した重合性化合物７ 、８、９の１０ｗｔ％ジエチルカーボネート溶液（1000ｐｐｍの過酸化ベンゾイル添加）を重量比９０：３：７０で混合し、各ゲル状組成物を得た。これら各組成物を約２５μｍのアルミ箔上に約１８０μｍの厚さに塗布成形した。さらに、約１００℃で６時間加熱硬化後、１００℃で８時間真空加熱乾燥することにより、コバルト酸リチウム／重合性化合物７及びコバルト酸リチウム／重合性化合物８及びコバルト酸リチウム／重合性化合物９複合正極シートを得た。これら各シートをポンチで１４ｍｍφに打ち抜き、電池用正極を得た。
【００５８】
実施例７：黒鉛負極の製造
ＭＣＭＢ黒鉛（大阪ガス製）、気相法黒鉛繊維（昭和電工（株）製：平均繊維径、0.3μｍ、平均繊維長、2.0μｍ、2700℃熱処理品）、実施例３、４、５で製造した重合性化合物７、８、９の１０ｗｔ％ジエチルカーボネート溶液（１０００ｐｐｍの過酸化ベンゾイル添加）を重量比８６：４：１００で混合し、各ゲル状組成物を得た。これら各組成物を約１５μｍの銅箔上に、約２５０μｍの厚さに塗布成形した。さらに、約１００℃で６時間加熱硬化後、１００℃で８時間真空加熱乾燥することにより、黒鉛／重合性化合物７及び黒鉛／重合性化合物８及び黒鉛／重合性化合物９複合負極シートを得た。これら各シートをポンチで１５ｍｍφに打ち抜き、電池用負極を得た。
【００５９】
比較例１：コバルト酸リチウム正極の製造
実施例６で製造したＬｉＣｏＯ₂粉末とアセチレンブラック、ポリフッ化ビニ リデン（ＰＶＤＦ）を重量比８：１：１で混合し、さらに過剰のＮ−メチルピロリドン溶液を加え、ゲル状組成物を得た。この組成物を約２５μｍのアルミ箔上に１８０μｍの厚さに塗布成形した。さらに、約１００℃で２４時間加熱真空乾燥することにより、コバルト酸リチウム正極シートを得た。このシートをポンチで１４ｍｍφに打ち抜き、電池用正極を得た。
【００６０】
比較例２：黒鉛負極の製造
ＭＣＭＢ黒鉛（大阪ガス製）、気相法黒鉛繊維（昭和電工（株）製：平均繊維径、0.3μｍ、平均繊維長、2.0μｍ、2700℃熱処理品）、ポリフッ化ビニリデン（ＰＶＤＦ）の重量比8.6：0.4：1.0の混合物に過剰のＮ−メチルピロリドン溶 液を加え、ゲル状組成物を得た。この組成物を約１５μｍの銅箔上に約２５０μｍの厚さに塗布成形した。さらに、約１００℃で２４時間加熱真空乾燥することにより、黒鉛負極を得た。このシートをポンチで１５ｍｍφに打ち抜き、電池用負極を得た。
【００６１】
実施例８〜１０：Ｌｉイオン二次電池の製造
実施例６、７で製造した各複合正極、負極を、表１に示す組み合わせで用い、以下に示す方法で、表１に示す３種類の黒鉛／コバルト酸リチウム系Ｌｉイオンコイン電池を得た（実施例８〜１０）。
アルゴン雰囲気グローブボックス中で各複合負極（１５ｍｍφ）にＬｉイオン電池用に脱水した電解液（１Ｍ ＬｉＰＦ₆／ＥＣ（エチレンカーボネート）＋ ＥＭＣ（エチルメチルカーボネート）（重量比３：７））を含浸させた。この複合負極上に旭化成製ポリオレフィンマイクロポーラスフィルム：ハイポア（開孔率６５％、厚み２５μｍ）に上記電解液を含浸させたものを貼り合わせ、さらに、各複合正極に上記電解液を含浸したものを貼り合わせ、2016コイン型缶（直径２０ｍｍ、厚み1.6ｍｍ）に封印し、黒鉛／コバルト酸リチウム系Ｌｉイオンコ イン電池を得た。
これら電池を２５℃、作動電圧2.75〜4.1Ｖ、充電0.8ｍＡ、放電6.0ｍＡで充 放電を繰り返した場合の最大放電容量及び容量が最大容量の５０％に低下するまでのサイクル数を表１に示す。
【００６２】
比較例３：Ｌｉイオン二次電池の製造
比較例１、２で製造した正極、負極を用いた以外は実施例８〜１０と同様の方法で表１に示す黒鉛／コバルト酸リチウム系Ｌｉイオンコイン電池を得た。
この電池を２５℃、作動電圧2.75〜4.1Ｖ、充電0.8ｍＡ、放電6.0ｍＡで充放 電を繰り返した場合の最大放電容量及び容量が最大容量の５０％に低下するまでのサイクル数を表１に示す。
【００６３】
【表１】

【００６４】
実施例１１：活性炭複合電極の製造
フェノール樹脂焼成品の水蒸気賦活活性炭（比表面積2010ｍ²／ｇ、平均粒径 ８μｍ、細孔容積0.7ｃｍ³／ｇ）、アセチレンブラック、実施例３、４、５で製造した重合性化合物７、８、９の１０ｗｔ％ジエチルカーボネート溶液（1000ｐｐｍの過酸化ベンゾイル添加）を重量比８６：４：１００で混合し、各ゲル状組成物を得た。これら各組成物を約２５μｍのアルミ箔上に、約２５０μｍの厚さに塗布成形した。さらに、約１００℃で６時間加熱硬化後、１００℃で８時間真空加熱乾燥することにより、活性炭／重合性化合物７及び活性炭／重合性化合物８、活性炭／重合性化合物９複合シートを得た。これら各シートをポンチで１５ｍｍφに打ち抜き、活性炭複合電極を得た。
【００６５】
比較例４：活性炭電極の製造
フェノール樹脂焼成品の水蒸気賦活活性炭（比表面積2010ｍ²／ｇ、平均粒径 ８μｍ、細孔容積0.7ｃｃ／ｇ）、アセチレンブラック、ポリフッ化ビニリデン （ＰＶＤＦ）の重量比8.6：0.4：1.0の混合物に過剰のＮ−メチルピロリドン溶 液を加え、ゲル状組成物を得た。この組成物を約２５μｍのアルミ箔上に、約１５０μｍの厚さに塗布成形した。さらに約１００℃で１０時間真空乾燥することにより、活性炭電極シートを得た。これら各シートをポンチで１５ｍｍφに打ち抜き、活性炭電極を得た。
【００６６】
実施例１２〜１４：コイン型電気二重層コンデンサの製造
実施例１１で製造した各活性炭複合電極２個を表２に示す組み合わせで用い、以下に示す方法で、表２に示す３種類のコイン型電気二重層コンデンサ（実施例１２〜１４）を得た。
アルゴン雰囲気グローブボックス中で複合電極（１５ｍｍφ）にＬｉイオン電池用に脱水した電解液（1.5Ｍ ＴＥＡＢ（テトラエチルアンモニウムテトラフ ルオロボレート／ＰＣ（プロピレンカーボネート））を含浸させた。この複合電極上にゴアテックス製テフロンマイクロポーラスフィルム（開孔率６０％、厚み２５μｍ）に上記電解液を含浸させたものを貼り合わせ、さらに、もう一つの同様の複合電極に上記電解液を含浸したものを貼り合わせ、2016コイン型缶（直径２０ｍｍ、厚み1.6ｍｍ）に封印し、コイン型電気二重層コンデンサを得た。
これらコンデンサを２５℃、作動電圧０〜2.5Ｖ、電流９ｍＡで充放電を行な った場合の最大放電容量及び充放電２００サイクル後の放電容量を表２に示す。
【００６７】
比較例５：コイン型電気二重層コンデンサの製造
比較例４で製造した活性炭電極２個を用いた以外は実施例１２〜１４と同様の方法で表２に示すコイン型電気二重層コンデンサを得た。
このコンデンサを２５℃、作動電圧０〜2.5Ｖ、電流９ｍＡで充放電を行なっ た場合の最大放電容量及び充放電５００サイクル後の放電容量を表２に示す。
【００６８】
【表２】

【００６９】
【発明の効果】
本発明のポリまたはオリゴカーボネート基を主成分とする架橋及び／または側鎖基を有する高分子化合物からなる電極用結着剤は、各種電極活物質や集電体との接着性が良好であり、弾性があり、電気化学的安定性や耐電解液性、耐熱性が良好であり、各種有機極性溶液を吸液、保持し、高イオン伝導性となり、これまでのフッ素系高分子を代表とする熱可塑性高分子からなる電極用結着剤に比較して、電極抵抗を低減でき、長寿命である。また、硬化性に優れるために硬化前のプレポリマーとして電極材料と混合後、容易に硬化できるので、従来の熱可塑性高分子からなる電極用結着剤に比較して加工面でも有利である。
本発明の電極用結着剤で成形された電極を用いることにより、高容量で作動でき、長寿命で、大電流特性、高温耐久性、信頼性、安定性、加工性に優れた二次電池が得られる。
さらに、本発明の電極用結着剤で成形された電極を用いることにより、出力電圧が高く、取り出し電流が大きく、長寿命で、高温耐久性、加工性、信頼性、安定性に優れた電気二重層コンデンサが得られる。従って、バックアップ電源だけでなく、小型電池との併用で、各種電気製品用電源として使用可能である。
【図面の簡単な説明】
【図１】 本発明による電池の一態様を示す薄型固体電池の模式的断面図である。
【図２】 本発明による固体電気二重層コンデンサの一態様を示す模式的断面図である。
【符号の説明】
１ 正極
２ 高分子固体電解質
３ 負極
４ａ，４ｂ 集電体
５ａ，５ｂ 絶縁性樹脂封止剤
６ａ，６ｂ 分極性電極
７ａ，７ｂ 集電体
８ 高分子固体電解質膜
９ 絶縁性樹脂封止剤
１０ リード線[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a binder useful for electrodes of various electrochemical devices. More specifically, a binder for an electrode comprising a polymer compound mainly composed of a poly or oligocarbonate group, an electrode using the binder, a method for producing the same, a battery using the electrode, and an electric double layer capacitor About.
[0002]
[Prior art]
Recently, LiCoO ₂ , LiNiO ₂ LiMnO ₂ , MoS ₂ Many researches have been made on lithium secondary batteries using metal oxides such as metal sulfides and metal sulfides for the positive electrode, and lithium, lithium alloys, carbon materials capable of occluding and releasing lithium ions, inorganic compounds, and polymer compounds for the negative electrode. . These have a high capacity per weight or volume and are attracting attention as high energy density secondary batteries.
[0003]
Furthermore, in recent years, an electric double layer capacitor in which a carbon material having a large specific surface area such as activated carbon or carbon black is used as a polarizable electrode and an ion conductive solution is disposed therebetween has been widely used for a memory backup power source. For example, a functional material, February 1989, page 33, describes a capacitor using a carbon-based polarizable electrode and an organic electrolyte.
[0004]
Electrodes are generally mixed with electrode active material powders or conductive powders such as carbon black, with a polymer binder, on a current collector such as a metal foil or carbon sheet. The one formed by binder molding is used. In particular, lithium secondary batteries and electric double layer capacitors that have been attracting attention in recent years use a solution in which a highly dissociated fluorine-based anionic electrolyte is dissolved in a highly polar organic solvent such as carbonate. The adhesive should be familiar with these electrolytes and should not dissolve or react. Also, since it is used in a wide potential range of 0 to 4.5 V with respect to the Li potential, a material that is stable in oxidation and reduction is required.
In addition, the active material expands and contracts with charge and discharge, and as a binder, a cushioning action is also required, and a material having elasticity to some extent is used. Moreover, since electrode drying is performed at high temperature, heat resistance is also required.
[0005]
As a polymer binder, in water-based batteries such as Ni / Cd and Ni / hydrogen secondary batteries, various water-soluble polymers such as polyvinyl chloride (PVC) and carboxymethyl cellulose (CMC), polytetrafluoroethylene (PTFE). Aqueous dispersions have been used.
Further, in lithium secondary batteries and organic electric double layer capacitors, polyvinylidene fluoride (PVDF) and its copolymers and fluorine-based polymers such as PTFE are mainly used. In addition, modified latex, polyimide, polyolefins such as polypropylene (PP) and polyethylene (PE), various thermosetting resins, polyurethane and the like are partially used or studied.
However, since the binders currently used place importance on the durability such as electrochemical stability and resistance to electrolytic solution, the compatibility with the electrolytic solution is not sufficient and the electrolytic solution cannot be included. Therefore, when used in a large amount, the resistance of the electrode is increased and partial inactivation is caused. Further, the adhesion between the active materials and the adhesion between the active material and the current collecting material are not sufficient. In particular, fluoropolymers and polyolefins have good durability, but affinity and adhesion are problems. Polyimide, latex, etc. with improved affinity and adhesiveness may be somewhat problematic in durability. Polyamide and polyester have good adhesion and heat resistance, but have not been put into practical use due to insufficient electrochemical stability, resistance to electrolytic solution, and the like. PVC and CMC used in the aqueous system cannot be used in the organic electrolyte system in terms of stability.
[0006]
In addition, currently used binders are basically dissolved or dispersed in various uncrosslinked solvents when mixed with electrode active material powders, so they melt and dissolve at high temperatures. There was a problem with heat resistance. Therefore, various thermosetting resins that can be crosslinked and polymerized by thermosetting after mixing with active material powder in the monomer state have been studied, but sufficient curing and stability have not been obtained. It was.
[0007]
[Problems to be solved by the invention]
The present invention is excellent in durability such as electrochemical stability, electrolytic solution resistance, heat resistance, etc., and has good adhesion to active material powder and current collecting material, and further impregnated with an electrolytic solution, and has high ion conductivity. It is an object of the present invention to provide a binder for electrodes useful for various electrochemical elements that are easily refined, an electrode using the same, and a method for producing the same. In particular, it is an object to provide a binder for an electrode useful for an organic electrolyte-type electrochemical element having high durability and required performance, and an electrode using the same.
Another object of the present invention is to provide a battery and an electric double layer capacitor that can operate at a high capacity and a large current using the electrode and are excellent in durability and reliability.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a polymer compound having a crosslink and / or a side chain group mainly composed of a poly or oligocarbonate group has an electrochemical stability, resistance to resistance. It has been found that it has excellent durability such as electrolyte solution and heat resistance, good adhesion to active material powders and current collecting materials, and is further impregnated with an electrolyte solution to facilitate high ion conductivity. In particular, the general formula (2) and / or the general formula (3)
[0009]
[Chemical 6]

[0010]
[The symbols in the formula have the same meaning as described below. ]
Since the polymerizable compound having a polymerizable functional group represented by the formula and having a poly or oligocarbonate group as a main component has good curability and can be easily crosslinked, it can be easily mixed with various electrode active material powders and is heat resistant. It has been found that this is an electrode binder with excellent properties.
Furthermore, it has been found that a battery or an electric double layer capacitor using an electrode obtained from the electrode binder has a high energy density, a large extraction current, and excellent durability and reliability.
[0011]
Based on the above findings, the present inventors used the following (1) electrode binder, (2) an electrode obtained from the electrode binder and a production method thereof, and (3) the electrode. Provide batteries and electric double layer capacitors.
[0012]
[1] The following general formula (2) and / or general formula (3)
[Chemical 3]

[Wherein R ² And R ^Three Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ^Four Represents a C1-C10 chain, branched and / or cyclic divalent group which may contain a hetero atom, and x is 0 or an integer of 1 to 10. However, multiple Rs exist in the same molecule. ² , R ^Three , R ^Four And x may be the same or different. ]
Having a polymerizable functional group represented by the general formula (1)
[Formula 4]

[Wherein R ¹ Represents a linear, branched and / or cyclic divalent group having 1 to 10 carbon atoms which may contain a hetero atom, m is an integer of 1 to 10, and n is 2 to 1000. It is an integer. However, multiple Rs exist in the same molecule. ¹ , M and n may be the same or different. ]
The binder used for the electrode for lithium secondary batteries or the polarizable electrode for electric double layer capacitors which consists of at least 1 type of heat | fever and / or actinic-light polymerizable compound which has the poly or oligocarbonate group shown by these as a main component.
[2] At least one electrode material for a lithium secondary battery selected from a lithium alloy, a carbon material, an inorganic oxide, an inorganic sulfide, and a conductive polymer compound, and the polymer of the binder described in 1 above. Including an electrode for a lithium secondary battery.
[3] For an electric double layer capacitor comprising at least one polarizable electrode material selected from a carbon material, an inorganic oxide, an inorganic sulfide, an inorganic halide, and a metal and the polymer of the binder described in 1 above Polarized electrode.
[4] A lithium secondary battery using the electrode according to 2 above.
[5] An electric double layer capacitor in which the polarizable electrode described in the above item 3 is used in an electric double layer capacitor in which a polarizable electrode is disposed via an ion conductive substance.
[6] The polymerizable compound according to 1 described above and the electrode material powder are mixed, or after further adding at least one organic solvent, the mixture is molded, and the polymerizable compound is polymerized. The manufacturing method of the electrode used for a lithium secondary battery or an electric double layer capacitor.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is described in detail below.
[Binder for electrode]
The polymer compound used in the electrode binder of the present invention has good adhesion to the electrode active material and current collector, has elasticity, and has good electrochemical stability, electrolytic solution resistance, and heat resistance, It can absorb and retain various organic polar solvents, and contains a cross-linked and / or side chain group having a poly or oligocarbonate structure represented by the following general formula (1).
[0017]
Embedded image

Where R ¹ Represents a divalent group having 1 to 10 carbon atoms, which may be a chain, branched and / or cyclic hetero atom, m is an integer of 1 to 10, and n is 2 to 1000. Is an integer.
[0018]
When m exceeds 10 in the above general formula (1), the number of carbonate groups in the polymer compound decreases, the heat resistance decreases, the dielectric constant decreases, and the compatibility with various polar solvents decreases, such being undesirable. Preferred m is 1-5.
R in the above general formula ¹ If the number of carbon atoms in the polymer compound is too large, the number of carbonate groups in the polymer compound decreases, and the heat resistance similarly decreases, which is not preferable. Further, the hydrophobicity of the polymer compound increases, and the compatibility with various polar solvents decreases, which is not preferable. Preferred R ¹ The number of carbon atoms is 1-4.
The repeating number n of the poly or oligocarbonate group represented by the general formula (1) in the polymer used for the electrode binder of the present invention is in the range of 2 to 1000, preferably in the range of 3 to 100, particularly 5-50 are preferable.
[0019]
The polymer used in the polymer solid electrolyte of the present invention has a poly or oligocarbonate group represented by the general formula (1) and a polymerizability represented by the following general formula (2) and / or (3). Functional group
Embedded image

[Wherein R ² And R ^Three Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ^Four Represents a chain, branched and / or cyclic divalent group which may contain a hetero atom, and x is 0 or an integer of 1 to 10. However, multiple Rs exist in the same molecule. ² , R ^Three , R ^Four And x may be the same or different. And a polymer of at least one heat and / or actinic ray polymerizable compound (hereinafter simply referred to as “polymerizable compound”) can be easily combined with electrodes used in various electrochemical devices, and Since heat resistance is also improved, it is preferable.
[0020]
Specific examples of the polymerizable compound include compounds represented by the following general formula (4) or (5).
Embedded image

Embedded image

Where R ^Five Represents a chain, branched and / or cyclic group having 1 to 20 carbon atoms which may contain a hetero atom, and other symbols have the same meanings as described above.
[0021]
There is no particular limitation on the method for synthesizing the polymerizable compound having the group represented by the general formula (1) and the group represented by the general formula (2). For example, a poly or oligo having an acid chloride and a terminal hydroxyl group It can be easily obtained by reacting with carbonateol in the following steps.
[0022]
Embedded image

Where R ¹ , M, n and R ² Represents the same meaning as described above.
[0023]
The method for synthesizing the polymerizable compound having the group represented by the general formula (1) and the group represented by the general formula (3) is not particularly limited.
Embedded image

It can be easily obtained by reacting the isocyanate compound represented by the above with poly or oligocarbonate ol having a hydroxyl group at the terminal.
[0024]
As a specific method, a compound having one functional group represented by the general formula (3) is, for example, a methacryloyl isocyanate compound (hereinafter abbreviated as MI) or an acryloyl isocyanate compound (hereinafter referred to as AI). And monoalkylpoly or oligocarbonateol can be easily obtained by reacting at a molar ratio of 1: 1 as in the following reaction.
[0025]
Embedded image

Where R ⁶ Represents an organic group having 1 to 10 carbon atoms, R ¹ , M, n, R ^Three , R ^Four And x represent the same meaning as described above.
[0026]
In addition, the compound having two functional groups represented by the general formula (3) can be easily obtained by reacting MI or AI with poly or oligocarbonate diol at a molar ratio of 2: 1 as follows. Is obtained.
[0027]
Embedded image

Where R ¹ , M, n, R ^Three , R ^Four And x represent the same meaning as described above.
The compound having three functional groups represented by the general formula (3) can be easily obtained by reacting, for example, MIs or AIs with poly or oligocarbonate triol at a molar ratio of 3: 1.
[0028]
Here, a polymer obtained by polymerizing a compound having only one functional group represented by the general formula (2) or (3) does not have a crosslinked structure, has low elasticity, and has low heat resistance. . Therefore, it is copolymerized with a polymerizable compound having two or more functional groups represented by the general formula (2) or (3) and crosslinked, or two functional groups represented by the general formula (2) or (3). It is preferable to use in combination with a polymer obtained from the polymerizable compound as described above.
[0029]
In addition, the polymer compound obtained by polymerizing the compound having a polymerizable functional group represented by the general formula (3) contains a urethane group, increases the dielectric constant, and increases the compatibility with various solvents. ,preferable. Furthermore, the compound having a polymerizable functional group represented by the general formula (3) is preferable because it has good polymerizability and can be easily cured after being combined with various electrodes.
[0030]
The polymer compound preferable as a constituent component of the binder for electrodes of the present invention may be a homopolymer of the polymerizable compound, two or more kinds of copolymers belonging to the same category, or the polymerization. It may be a copolymer of at least one kind of polymerizable compound and another polymerizable compound.
[0031]
The other polymerizable compound copolymerizable with the polymerizable compound is not particularly limited, and examples thereof include (meth) acrylic acid alkyl esters such as methyl methacrylate and n-butyl acrylate, and various urethane (meth) acrylates. , (Meth) acrylic acid ester and / or urethane (meth) acrylate having a oxyalkylene and / or oxyfluorocarbon chain, (meth) acrylic acid fluorinated alkyl ester, acrylamide, methacrylamide, N, N-dimethylacrylamide, N, (Meth) acrylamides such as N-dimethylmethacrylamide, vinylene carbonate, (meth) acryloyl carbonate, N-vinylpyrrolidone, acryloylmorpholine, methacryloylmorpholine, N, N-dimethylaminopropyl (meth) acrylamide Compound, styrene, alpha-methylstyrene styrene compounds such as, N- vinylacetamide, N- vinyl amide compounds such as N- vinylformamide, and alkyl vinyl ethers such as ethyl vinyl ether.
[0032]
Among these, (meth) acrylic acid ester, urethane (meth) acrylate, or (meth) acrylic acid ester and / or urethane (meth) acrylate having an oxyalkylene and / or oxyfluorocarbon chain is preferably used. Among these, urethane (meth) acrylate is particularly preferable from the viewpoint of polymerizability.
[0033]
The polymer compound used in the electrode binder of the present invention includes a polymer obtained from at least one of the polymerizable compounds and / or a copolymer containing the polymerizable compound as a copolymer component, and other compounds. It may be a mixture with a polymer compound. Other polymer compounds to be mixed include, for example, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polybutadiene, polymethacrylic (or acrylic) esters, polystyrene, polyphosphazenes, polysiloxane or polysilane, polyvinylidene fluoride, polytetra Examples thereof include polymers such as fluoroethylene.
[0034]
The amount of the structural unit derived from the polymer having a poly or oligocarbonate group represented by the general formula (1) may be obtained by homopolymerizing the polymerizable compound, copolymerizing with other copolymerization components, or other Since it differs depending on whether the polymer compound is mixed or depending on the type of the compound, it cannot be said unconditionally, but when used as a binder for electrodes, the adhesiveness, electrochemical stability, heat resistance, In consideration of compatibility, it is preferably contained in an amount of 50% by weight or more, more preferably 70% by weight or more based on the total amount of the polymer component.
[0035]
Polymerization of the polymerizable compound can be performed by a general method utilizing the polymerizability of an acryloyl group or methacryloyl group which is a functional group. That is, the polymerizable compound alone, or a mixture of a polymerizable compound and another polymerizable compound that can be copolymerized with the above, a heating radical polymerization catalyst such as azobisisobutyronitrile and benzoyl peroxide, an activity such as benzyl methyl ketal Photoradical polymerization catalyst CF _Three Protonic acid such as COOH, BF _Three AlCl _Three Radical polymerization, cationic polymerization, or anionic polymerization can be performed using a cationic polymerization catalyst such as Lewis acid or the like, or an anionic polymerization catalyst such as butyl lithium, sodium naphthalene, or lithium alkoxide.
[0036]
The polymerization temperature depends on the type of the polymerizable compound, but may be any temperature at which polymerization occurs, and is usually performed in the range of 0 ° C to 200 ° C.
When polymerizing by irradiation with actinic rays, depending on the type of the polymerizable compound, for example, using an initiator such as benzylmethyl ketal or benzophenone, irradiation with ultraviolet light of several mW or more, γ rays, electron beams, etc. And can be polymerized.
[0037]
[Electrode and manufacturing method thereof]
The electrode of the present invention is formed by binding electrode material powder used for various electrochemical elements with the electrode binder of the present invention.
As the positive electrode material of the battery electrode of the present invention, by using an electrode active material (positive electrode active material) having a high redox potential such as a metal oxide, metal sulfide, conductive polymer or carbon material, a high voltage This is preferable because a high-capacity battery can be obtained. Among such positive electrode active materials, metal oxides such as cobalt oxide, manganese oxide, vanadium oxide, nickel oxide, and molybdenum oxide, molybdenum sulfide, titanium sulfide, Metal sulfides such as vanadium sulfide are preferable, and manganese oxide, nickel oxide, cobalt oxide, and the like are particularly preferable in terms of high capacity and high voltage. The method for producing the metal oxide or metal sulfide in this case is not particularly limited. For example, a general electrolysis method or heating as described in Electrochemistry, Vol. 22, page 574 (1954). Manufactured by law. Further, when these are used as an electrode active material in a lithium battery, for example, Li _x CoO ₂ Or Li _x MnO ₂ The lithium element is preferably used in a state of being inserted (composited) into a metal oxide or metal sulfide. The method for inserting the lithium element is not particularly limited. For example, a method for electrochemically inserting lithium ions or a method described in US Pat. No. 4,357,215 may be used. ₂ CO _Three This can be carried out by mixing and heat-treating a salt of the above and a metal oxide.
[0038]
In terms of flexibility and easy thinning, a conductive polymer is preferable as the positive electrode active material. Examples of the conductive polymer include polyaniline, polyacetylene and derivatives thereof, polyparaphenylene and derivatives thereof, polypyrrole and derivatives thereof, polythienylene and derivatives thereof, polypyridinediyl and derivatives thereof, polyisothianaphthenylene and derivatives thereof, polyfurylene. And derivatives thereof, polyselenophene and derivatives thereof, polyparaphenylene vinylene, polythienylene vinylene, polyfurylene vinylene, polynaphthenylene vinylene, polyselenophene vinylene, polypyridine diyl vinylene, and their derivatives, etc. Is mentioned. These conductive polymers are produced according to a general chemical or electrochemical oxidative polymerization method or other known methods.
Further, examples of the carbon material include natural graphite, artificial graphite, gas phase method graphite, petroleum coke, coal coke, fluorinated graphite, pitch-based carbon, and polyacene.
[0039]
As the negative electrode active material of the battery electrode of the present invention, a material having a low redox potential using an alkali metal ion as a carrier such as an alkali metal, an alkali metal alloy, a carbon material, a metal oxide or a conductive polymer compound is used. This is preferable because a battery having a high voltage and a high capacity can be obtained. Among such negative electrode active materials, lithium metal or lithium alloys such as lithium / aluminum alloy, lithium / lead alloy, and lithium / antimony alloy have the lowest redox potential and can be made thin. preferable. Carbon materials are also particularly preferred in that they have a low redox potential when lithium ions are occluded, and are stable and safe. Examples of the material capable of occluding and releasing lithium ions include natural graphite, artificial graphite, gas phase method graphite, petroleum coke, coal coke, pitch-based carbon, polyacene, fullerenes such as C60 and C70, and the like.
[0040]
Various carbon materials are mentioned as a polarizable material used for the polarizable electrode for electric double layer capacitors of the present invention. The carbon material is not particularly limited as long as the specific surface area is large, but the larger the specific surface area, the larger the capacity of the electric double layer, which is preferable. For example, carbon blacks such as furnace black, thermal black (including acetylene black), channel black, activated carbon such as coconut shell charcoal, natural graphite, artificial graphite, so-called pyrolytic graphite produced by a gas phase method, polyacene and C60 , C70. Those obtained by further increasing the specific surface area by steam treatment or acid treatment are preferred.
[0041]
As a method of forming these electrode materials into electrodes, after mixing the polymerizable compound having the poly or oligocarbonate group of the present invention and the electrode material powder in an appropriate ratio, or further, a conductive assistant such as carbon black or at least one kind. After adding the above solvent, a method is recommended in which the mixture is applied and / or molded, and the polymerizable compound is polymerized by heating or irradiation with actinic light to cure the entire electrode.
[0042]
The solvent may be used for uniform mixing of the electrode material powder and the polymerizable compound, or for reducing the viscosity of the mixture so as to facilitate subsequent application molding. As the solvent to be used, those having good compatibility with the polymerizable compound or electrode material having a poly or oligocarbonate group of the present invention are suitable. These solvents are often removed by drying or the like after the production of the electrode. However, when remaining in the electrode, a compound that has a wide electrochemical stability range and does not adversely affect the electrochemical device to be used is suitable. Examples of such solvents include ethers such as 1,2-dimethoxyethane, 2-methyltetrahydrofuran, crown ether, triethylene glycol methyl ether, tetraethylene glycol dimethyl ether, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl Examples thereof include carbonates such as methyl carbonate, aromatic nitriles such as benzonitrile and tolunitrile, sulfur compounds such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, N-vinylpyrrolidone and sulfolane, and phosphate esters. Among these, ethers and carbonates are preferable, and carbonates are particularly preferable.
[0043]
[Battery configuration]
The battery of the present invention uses an electrode using a polymerizable compound having a poly or oligocarbonate group as a binder for an electrode, and is characterized by a large extraction current or excellent workability and reliability. As an example of the battery of the present invention, a schematic cross-sectional view of a thin film battery is shown in FIG. In the figure, 1 is a positive electrode, 2 is a polymer solid electrolyte, 3 is a negative electrode, 4a and 4b are current collectors, and 5a and 5b are insulating resin sealants.
[0044]
In particular, a battery using alkali metal ions as a carrier has a high output voltage and a high energy density. In this case, an alkali metal salt is used as the electrolyte salt of the electrolyte layer. As an alkali metal salt, for example, LiCF _Three SO _Three , LiPF ₆ LiClO _Four , LiBF _Four , LiSCN, LiAsF ₆ , LiN (CF _Three SO ₂ ) ₂ , LiN (C F _Three CF ₂ SO ₂ ) ₂ , NaCF _Three SO _Three , LiI, NaPF ₆ , NaClO _Four , NaI, NaBF _Four , NaAsF ₆ , KCF _Three SO _Three , KPF ₆ KI etc. can be mentioned.
[0045]
The battery structure or the support may be made of a metal such as SUS, a resin such as polypropylene or polyimide, or a ceramic material such as conductive or insulating glass. It is not limited. The shape may be any shape such as a cylinder, a box, a sheet or the like.
[0046]
[Configuration of electric double layer capacitor]
Next, the electric double layer capacitor of the present invention will be described.
The electric double layer capacitor of the present invention uses an electrode using a polymerizable compound having a poly or oligocarbonate group as a binder for an electrode, and has a large extraction current or excellent workability and reliability. There is a feature.
[0047]
FIG. 2 shows a schematic cross-sectional view of an example of the electric double layer capacitor of the present invention. In this example, a thin cell having a size of 1 cm × 1 cm and a thickness of about 0.5 mm, 7a and 7b are current collectors, and a pair of polarizable electrodes 6a and 6b are arranged inside the current collectors. The polymer solid electrolyte membrane 8 is disposed between them. 9 is an insulating resin sealant, and 10 is a lead wire.
The current collectors 7a and 7b are preferably made of a material having electronic conductivity and electrochemical corrosion resistance, and a specific surface area as large as possible. For example, various metals and their sintered bodies, electron conductive polymers, carbon sheets and the like can be mentioned.
[0048]
The type of electrolyte salt used in the electrolyte layer in the case of the electric double layer capacitor of the present invention is not particularly limited, and a compound containing an ion desired to be a charge carrier may be used, but the dissociation constant in the electrolyte layer is large. It is desirable to include ions that easily form a polarizable electrode and an electric double layer. Such compounds include (CH _Three ) _Four NBF _Four , (CH _Three CH ₂ ) _Four NClO _Four Quaternary ammonium salt such as pyridinium salt, AgClO _Four Transition metal salts such as (CH _Three ) _Four PBF _Four Quaternary phosphonium salts such as LiCF _Three SO _Three , LiPF ₆ LiClO _Four , LiI, LiBF _Four , LiSCN, LiAsF ₆ , LiN (CF _Three SO ₂ ) ₂ , LiN (CF _Three CF ₂ SO ₂ ) ₂ , NaCF _Three SO _Three , NaPF ₆ , NaClO _Four , NaI, NaBF _Four , NaAsF ₆ , KCF _Three SO _Three , KPF ₆ And alkali metal salts such as KI, organic acids such as p-toluenesulfonic acid and salts thereof, and inorganic acids such as hydrochloric acid and sulfuric acid. Of these, quaternary ammonium salts, pyridinium salts, quaternary phosphonium salts, and alkali metal salts are preferred from the viewpoints of high output voltage and a large dissociation constant.
[0049]
The capacitor structure or the support may be a metal such as SUS, a resin such as polypropylene or polyimide, or a ceramic material such as conductive or insulating glass. The shape is not limited to the above, and the shape may be any shape such as a cylinder, a box, a sheet or the like.
[0050]
As the shape of the electric double layer capacitor, in addition to the sheet type as shown in FIG. 2, a coin type, or a sheet-like laminate of a polarizable electrode and a polymer solid electrolyte is wound into a cylindrical shape to form a cylindrical tubular capacitor. It may be a cylindrical type manufactured by sealing in a structure.
[0051]
【Example】
The present invention will be described in more detail below with typical examples. Note that these are merely illustrative examples, and the present invention is not limited thereto.
[0052]
Example 1: Synthesis of compounds 1, 2 and 3
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In accordance with the above formulas (a), (b) and (c), excess phosgene gas was blown into various alkylene glycols under nitrogen at 10 ° C. or lower in a conventional manner and allowed to react for about 5 hours. Compound 1, Compound 2, and Compound 3 were synthesized. These identifications were performed by GC-MS.
[0053]
Example 2: Oligomerization of compounds 1, 2 and 3 (synthesis of compounds 4, 5 and 6)
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According to the above formulas (d), (e), and (f), various alkylene glycol bischloroformates (compounds 1, 2, 3) synthesized in Example 1 and various alkylene glycols in the presence of pyridine. After reacting in dichloromethane at 25 ° C. or less for about 6 hours, excess water is added to hydroxylate the remaining chloroformate terminals, and oligocarbonates (compound 4, compound 5, compound 6) having hydroxyl groups at both ends are obtained. Synthesized.
The average of the weight average molecular weight (Mw) and the number of repetitions x, y, z of each oligocarbonate determined by GPC analysis was as follows.
Compound 4 Mw to about 800, x: to about 8,
Compound 5 Mw to about 1500, y: to about 10,
Compound 6 Mw to about 1200, z: to about 10.
[0054]
Example 3: Synthesis of polymerizable compound 7
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Compound 4 (average molecular weight 800) (40.0 g) and MOI (methacryloyloxyethyl isocyanate) (15.5 g) were dissolved in well-purified THF (200 ml) in a nitrogen atmosphere, and then dibutyltin dilaurate (0.44 g) was added. . Then, the colorless product was obtained by making it react at 25 degreeC for about 15 hours. That ¹ From the results of 1 H-NMR, IR, and elemental analysis, compound 4 and MOI reacted in a one-to-two manner, the isocyanate group of MOI disappeared, a urethane bond was formed, and polymerizable compound 7 was formed. I understood it.
[0055]
Example 4: Synthesis of polymerizable compound 8
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Compound 5 (average molecular weight 1500) (75.0 g) and MOI (15.5 g) were dissolved in well-purified THF (200 ml) in a nitrogen atmosphere, and then dibutyltin dilaurate (0.44 g) was added. Then, the colorless product was obtained by making it react at 25 degreeC for about 15 hours. That ¹ From the results of H-NMR, IR, and elemental analysis, compound 5 and MOI reacted in a one-to-two manner, the isocyanate group of MOI disappeared, a urethane bond was formed, and polymerizable compound 8 was formed. I understood it.
[0056]
Example 5: Synthesis of polymerizable compound 9
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Compound 6 (average molecular weight 1200) (60.0 g) and MOI (15.5 g) were dissolved in well-purified THF (200 ml) in a nitrogen atmosphere, and then dibutyltin dilaurate (0.44 g) was added. Then, the colorless product was obtained by making it react at 25 degreeC for about 15 hours. That ¹ From the results of H-NMR, IR, and elemental analysis, compound 6 and MOI reacted in a one-to-two manner, the isocyanate group of MOI disappeared, a urethane bond was formed, and polymerizable compound 9 was formed. I understood it.
[0057]
Example 6: Production of lithium cobaltate positive electrode
11g Li ₂ CO _Three And 24g Co _Three O _Four Were mixed well, heated at 800 ° C. for 24 hours in an oxygen atmosphere, and then pulverized to obtain LiCoO ₂ A powder was obtained. This LiC oO ₂ Powder and acetylene black, 10 wt% diethyl carbonate solution (1000 ppm benzoyl peroxide added) of polymerizable compounds 7, 8, and 9 prepared in Examples 3, 4, and 5 were mixed at a weight ratio of 90: 3: 70, A gel composition was obtained. Each of these compositions was applied and molded on an aluminum foil of about 25 μm to a thickness of about 180 μm. Furthermore, after heat-curing at about 100 ° C. for 6 hours and then vacuum-heat drying at 100 ° C. for 8 hours, lithium cobaltate / polymerizable compound 7, lithium cobaltate / polymerizable compound 8, and lithium cobaltate / polymerizable compound 9 A composite positive electrode sheet was obtained. Each of these sheets was punched out to 14 mmφ with a punch to obtain a positive electrode for a battery.
[0058]
Example 7: Production of graphite negative electrode
MCMB graphite (manufactured by Osaka Gas), gas phase process graphite fiber (manufactured by Showa Denko KK: average fiber diameter, 0.3 μm, average fiber length, 2.0 μm, heat treated product at 2700 ° C.), manufactured in Examples 3, 4 and 5 Polymeric compounds 7, 8, and 9 in 10 wt% diethyl carbonate solution (1000 ppm of benzoyl peroxide added) were mixed at a weight ratio of 86: 4: 100 to obtain gel compositions. Each of these compositions was applied and molded on a copper foil of about 15 μm to a thickness of about 250 μm. Furthermore, after heating and curing at about 100 ° C. for 6 hours, vacuum heating drying at 100 ° C. for 8 hours was performed to obtain a graphite / polymerizable compound 7, graphite / polymerizable compound 8, and graphite / polymerizable compound 9 composite negative electrode sheet. . Each of these sheets was punched to 15 mmφ with a punch to obtain a negative electrode for a battery.
[0059]
Comparative Example 1: Production of lithium cobaltate positive electrode
LiCoO produced in Example 6 ₂ The powder, acetylene black, and polyvinylidene fluoride (PVDF) were mixed at a weight ratio of 8: 1: 1, and an excess N-methylpyrrolidone solution was added to obtain a gel composition. This composition was applied and molded on an aluminum foil of about 25 μm to a thickness of 180 μm. Furthermore, the lithium cobaltate positive electrode sheet was obtained by heating and vacuum-drying at about 100 degreeC for 24 hours. This sheet was punched to 14 mmφ with a punch to obtain a positive electrode for a battery.
[0060]
Comparative Example 2: Production of graphite negative electrode
MCMB graphite (manufactured by Osaka Gas), gas phase process graphite fiber (manufactured by Showa Denko KK: average fiber diameter, 0.3 μm, average fiber length, 2.0 μm, heat treated product at 2700 ° C.), weight ratio of polyvinylidene fluoride (PVDF) An excess N-methylpyrrolidone solution was added to the 8.6: 0.4: 1.0 mixture to obtain a gel composition. This composition was applied and molded to a thickness of about 250 μm on a copper foil of about 15 μm. Furthermore, a graphite negative electrode was obtained by heating and vacuum drying at about 100 ° C. for 24 hours. This sheet was punched into 15 mmφ with a punch to obtain a negative electrode for a battery.
[0061]
Examples 8 to 10: Production of Li-ion secondary battery
Using each composite positive electrode and negative electrode produced in Examples 6 and 7 in combinations shown in Table 1, three types of graphite / lithium cobaltate Li-ion coin batteries shown in Table 1 were obtained by the following method ( Examples 8 to 10).
Electrode solution (1M LiPF) dehydrated for Li-ion batteries on each composite negative electrode (15mmφ) in an argon atmosphere glove box ₆ / EC (ethylene carbonate) + EMC (ethyl methyl carbonate) (weight ratio 3: 7)). On this composite negative electrode, a polyolefin microporous film manufactured by Asahi Kasei Co., Ltd .: a composite (impregnated with the above electrolyte solution on a hypopore (porosity 65%, thickness 25 μm)) was bonded, and each composite positive electrode was impregnated with the above electrolyte solution. They were bonded together and sealed in a 2016 coin-shaped can (diameter 20 mm, thickness 1.6 mm) to obtain a graphite / lithium cobaltate Li-ion coin battery.
Table 1 shows the maximum discharge capacity and the number of cycles until the capacity drops to 50% of the maximum capacity when these batteries are repeatedly charged and discharged at 25 ° C, operating voltage 2.75 to 4.1 V, charge 0.8 mA, discharge 6.0 mA. Show.
[0062]
Comparative Example 3: Production of Li ion secondary battery
A graphite / lithium cobaltate Li-ion coin battery shown in Table 1 was obtained in the same manner as in Examples 8 to 10 except that the positive electrode and the negative electrode manufactured in Comparative Examples 1 and 2 were used.
Table 1 shows the maximum discharge capacity and the number of cycles until the capacity drops to 50% of the maximum capacity when this battery is repeatedly charged and discharged at 25 ° C, operating voltage 2.75 to 4.1V, charge 0.8mA, discharge 6.0mA. Shown in
[0063]
[Table 1]

[0064]
Example 11: Production of activated carbon composite electrode
Steam activated carbon activated by phenol resin fired product (specific surface area 2010m ² / G, average particle size 8μm, pore volume 0.7cm ^Three / G), acetylene black, 10 wt% diethyl carbonate solution (1000 ppm of benzoyl peroxide added) of polymerizable compounds 7, 8, and 9 prepared in Examples 3, 4, and 5 were mixed at a weight ratio of 86: 4: 100. Each gel composition was obtained. Each of these compositions was applied and molded on an aluminum foil of about 25 μm to a thickness of about 250 μm. Furthermore, after heating and curing at about 100 ° C. for 6 hours, vacuum heating drying was performed at 100 ° C. for 8 hours to obtain activated carbon / polymerizable compound 7, activated carbon / polymerizable compound 8, and activated carbon / polymerizable compound 9 composite sheet. Each of these sheets was punched to 15 mmφ with a punch to obtain an activated carbon composite electrode.
[0065]
Comparative Example 4: Production of activated carbon electrode
Steam activated carbon activated by phenol resin fired product (specific surface area 2010m ² / G, average particle size 8 μm, pore volume 0.7 cc / g), an excess N-methylpyrrolidone solution is added to a mixture of acetylene black and polyvinylidene fluoride (PVDF) in a weight ratio of 8.6: 0.4: 1.0 to form a gel A composition was obtained. This composition was applied and molded on an aluminum foil of about 25 μm to a thickness of about 150 μm. Furthermore, the activated carbon electrode sheet was obtained by vacuum-drying at about 100 degreeC for 10 hours. Each of these sheets was punched to 15 mmφ with a punch to obtain an activated carbon electrode.
[0066]
Examples 12 to 14: Manufacture of coin-type electric double layer capacitor
Using the two activated carbon composite electrodes produced in Example 11 in the combinations shown in Table 2, three types of coin-type electric double layer capacitors (Examples 12 to 14) shown in Table 2 were obtained by the method shown below. .
In an argon atmosphere glove box, a composite electrode (15 mmφ) was impregnated with a dehydrated electrolyte (1.5 M TEAB (tetraethylammonium tetrafluoroborate / PC (propylene carbonate)) for Li-ion batteries. A Teflon microporous film (aperture ratio 60%, thickness 25 μm) made by impregnating the above electrolyte solution was bonded, and another similar composite electrode impregnated with the above electrolyte solution was bonded. A coin-shaped can (diameter 20 mm, thickness 1.6 mm) was sealed to obtain a coin-type electric double layer capacitor.
Table 2 shows the maximum discharge capacity and the discharge capacity after 200 cycles of charge and discharge when these capacitors are charged and discharged at 25 ° C., operating voltage 0 to 2.5 V, and current 9 mA.
[0067]
Comparative Example 5: Manufacture of coin-type electric double layer capacitor
A coin-type electric double layer capacitor shown in Table 2 was obtained in the same manner as in Examples 12 to 14 except that the two activated carbon electrodes produced in Comparative Example 4 were used.
Table 2 shows the maximum discharge capacity and the discharge capacity after 500 cycles of charge and discharge when this capacitor is charged and discharged at 25 ° C., operating voltage 0 to 2.5 V, and current 9 mA.
[0068]
[Table 2]

[0069]
【The invention's effect】
The binder for an electrode comprising a polymer compound having a cross-linked and / or side chain group mainly composed of a poly or oligocarbonate group of the present invention has good adhesion to various electrode active materials and current collectors. It has elasticity, electrochemical stability, electrolytic solution resistance, heat resistance is good, absorbs and holds various organic polar solutions, and has high ionic conductivity. Compared with a binder for electrodes made of a thermoplastic polymer, the electrode resistance can be reduced and the life is long. Further, since it is excellent in curability, it can be easily cured after being mixed with an electrode material as a prepolymer before curing, and therefore, it is advantageous in terms of processing as compared with a conventional binder for electrodes made of thermoplastic polymer.
By using the electrode molded with the electrode binder of the present invention, the secondary battery can operate at a high capacity, has a long life, and has high current characteristics, high temperature durability, reliability, stability, and workability. Is obtained.
Furthermore, by using the electrode molded with the electrode binder of the present invention, the output voltage is high, the take-out current is large, the life is long, the high temperature durability, workability, reliability, and stability are excellent. A double layer capacitor is obtained. Therefore, it can be used not only as a backup power source but also as a power source for various electric products in combination with a small battery.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a thin solid battery showing one embodiment of a battery according to the present invention.
FIG. 2 is a schematic cross-sectional view showing one embodiment of a solid electric double layer capacitor according to the present invention.
[Explanation of symbols]
1 Positive electrode
2 Polymer solid electrolyte
3 Negative electrode
4a, 4b Current collector
5a, 5b Insulating resin sealant
6a, 6b Polarized electrode
7a, 7b Current collector
8 Polymer solid electrolyte membrane
9 Insulating resin sealant
10 Lead wire

Claims (6)

The following general formula (2) and / or general formula (3)

[Wherein R ² and R ³ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁴ contains a chain, branched and / or cyclic hetero atom having 1 to 10 carbon atoms. And x is an integer of 0 or 1 to 10. However, a plurality of R ² , R ³ , R ⁴ and x existing in the same molecule may be the same or different. ]
Having a polymerizable functional group represented by the general formula (1)

[Wherein R ¹ represents a chain, branched and / or cyclic divalent group which may contain a hetero atom, and m is an integer of 1 to 10; n is an integer of 2 to 1000. However, a plurality of R ¹ , m and n existing in the same molecule may be the same or different. ]
A binder for an electrode for a lithium secondary battery or a polarizable electrode for an electric double layer capacitor, comprising at least one heat and / or actinic ray-polymerizable compound having a poly or oligocarbonate group as a main component.   A lithium containing at least one electrode material for a lithium secondary battery selected from a lithium alloy, a carbon material, an inorganic oxide, an inorganic sulfide, and a conductive polymer compound, and the polymer of the binder according to claim 1. Secondary battery electrode.   Polarizability for an electric double layer capacitor comprising at least one polarizable electrode material selected from a carbon material, an inorganic oxide, an inorganic sulfide, an inorganic halide, and a metal, and the polymer of the binder according to claim 1. electrode.   A lithium secondary battery using the electrode according to claim 2.   4. An electric double layer capacitor, wherein the polarizable electrode according to claim 3 is used in an electric double layer capacitor in which a polarizable electrode is disposed via an ion conductive material.   The polymerizable compound according to claim 1 is mixed with the electrode material powder, or after further adding at least one organic solvent, the mixture is molded, and the polymerizable compound is polymerized. Manufacturing method of electrode for secondary battery or electric double layer capacitor.

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