JP2004006285A - Lithium secondary battery - Google Patents
Lithium secondary battery Download PDFInfo
- Publication number
- JP2004006285A JP2004006285A JP2003090641A JP2003090641A JP2004006285A JP 2004006285 A JP2004006285 A JP 2004006285A JP 2003090641 A JP2003090641 A JP 2003090641A JP 2003090641 A JP2003090641 A JP 2003090641A JP 2004006285 A JP2004006285 A JP 2004006285A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- active material
- conductive
- binder
- secondary battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
Description
【0001】
【発明の属する技術分野】
本発明は携帯機器の電源等として用いられるリチウム二次電池に関する。
【0002】
【従来の技術】
リチウムイオン二次電池は、高出力化電池という点で携帯機器用途の電源として広く用いられてきている。リチウムイオン二次電池は既に上市されてから十年以上が経過し、特性も改善されてきている。リチウムイオン二次電池に関しては、高容量であること、安全性が高いことが技術課題として重点が置かれている。
【0003】
リチウムイオン二次電池では、従来、電極の製造は電極活物質と結着剤、そして必要に応じて導電助剤を結着剤溶液中に分散させ、スラリーとした後、集電体である金属箔等に塗布することで行われている。電極には必要により導電助剤が添加されるが、その材料としては、通常、黒鉛、カーボンブラック、アセチレンブラック、炭素繊維、ニッケル、アルミニウム、銅、銀等の金属が用いられ、特に黒鉛、カーボンブラック、アセチレンブラックが用いられている。
【0004】
リチウムイオン二次電池の正極活物質としては、通常リチウムイオンをその構造中に吸蔵放出可能な物質である、コバルト酸リチウム、ニッケル酸リチウム、マンガン酸リチウム等のリチウム含有金属酸化物や、これらにアルミニウム、マンガン、スズ、鉄、銅、マグネシウム、チタン、亜鉛、モリブデン等の金属元素を少なくとも一つ添加したリチウム含有複合金属酸化物が用いられている。
【0005】
しかし、これらの金属酸化物は、電子導電性に乏しいため、リチウムイオン二次電池の電極として用いるためには導電助剤が必要になる。
【0006】
導電助剤としては、良好な導電ネットワークを構築するカーボンブラックやアセチレンブラックが好んで用いられている。これらを正極の導電助剤として用いる場合、導電助剤を活物質とともに結着剤溶液中に分散させて塗料化し、集電体である金属箔、例えばアルミニウム箔等に塗布後、乾燥し圧延することで電極化する。
【0007】
ところが、この電極乾燥の際に、カーボンブラックやアセチレンブラックおよび結着剤は比重が軽いため、溶剤として用いている溶媒の蒸発に伴い、塗膜表面付近まで浮き上がってしまい、活物質、導電助剤および結着剤の密着から得られる良好な導電パスや集電体と活物質との密着性に問題を生じることになる。そして、この影響は電極厚みが増すにつれ顕著になる。このため、従来の正極では単位面積あたりの正極活物質担持量は20mg/cm2以下に抑えなければならず、このことがリチウムイオン二次電池のさらなる高エネルギー密度化および高出力化への妨げになっている。
【0008】
従来の湿式法による電極化では、電極塗布後の乾燥時に導電助剤および結着剤が集電体箔から離れ、導電性および集電体との密着性の低下を招いてしまう。この現象は、特に電子伝導性に乏しい電極活物質を用い、かつ厚膜電極を作成するときに顕著になり、電池特性を発揮する上で非常に大きな障害となっている。具体的には、リチウムイオン二次電池の正極に、上述した正極活物質を用い、その単位面積あたりの活物質担持量が20mg/cm2以上の正極を用いる場合に顕著になり、30mg/cm2以上の担持量では実用に供さないレベルにまで、その電池特性は低下する。
【0009】
また、例えば、リチウムイオンを吸蔵放出可能な炭素材料やチタン系酸化物を負極活物質として用いる場合や、バナジウム系酸化物を正極活物質として用いる場合などで厚膜電極を用いる場合にも同様である。こうした問題を解決するには、従来の電極よりも良好な導電パスを電極材料中で構築させなければならなかった。
【0010】
【本発明が解決しようとする課題】
本発明の目的は、上記問題を解決し、さらなる高エネルギー密度化および高出力密度化を可能とし、用途の拡大に寄与できるリチウム二次電池を提供することである。
【0011】
【課題を解決するための手段】
すなわち上記目的は、以下の本発明の構成により達成される。
(1) 少なくともリチウムイオンを吸蔵放出可能な電極活物質と、結着剤と、集電体とを有する正極および負極と、電解液とを有し、
前記正極または負極の少なくともいずれかの電極に含まれる電極活物質が、その表面に導電助剤と、結着剤とを被覆させることで導電処理され、かつこの電極活物質が乾式法で集電体表面に担持されているリチウム二次電池。
(2) 前記導電処理された活物質含有層がシート化され、導電性接着層を有する集電体に接着されている上記(1)のリチウム二次電池。
(3) 前記導電性接着層は、少なくとも導電助剤および結着剤を含有し、塗布法により形成されている上記(2)のリチウム二次電池。
(4) 前記電極の単位面積あたりの活物質担持量が20mg/cm2以上である上記(1)〜(3)のいずれかのリチウム二次電池。
(5) 前記電極の活物質が炭素系材料であり、電極の単位面積あたりの活物質担持量が15mg/cm2以上である上記(1)〜(3)のいずれかのリチウム二次電池。
【0012】
【発明の実施の形態】
本発明のリチウム二次電池は、少なくともリチウムイオンを吸蔵放出可能な電極活物質と、結着剤と、集電体とを有する正極および負極と、電解液とを有し、前記正極または負極の少なくともいずれかの電極に含まれる電極活物質が、その表面に導電助剤と、結着剤とを被覆させることで導電処理され、かつこの電極活物質が乾式法で集電体表面に担持されているものである。
【0013】
本発明は、電極中の活物質含有層に効果的な導電ネットワークを構築し、単位面積あたりの活物質担持量を増大させ、電極を厚膜とすることで、電池のエネルギー密度および出力密度を上昇させることに関するものである。そのためには、電極活物質に従来よりも良好な導電性を持たせることが必要となる。この点については、電極活物質表面に導電性を付与する処理が必要であり、具体的には導電助剤および結着剤を活物質表面に密着させる目的で複合化処理を行うことで解決できる。そして、得られた電極材料を乾式法により電極化し、目的の高エネルギー密度電池、および高出力密度電池が得られる。
【0014】
すなわち、乾式法で処理することにより、従来の電極塗布後の乾燥時に導電助剤および結着剤が活物質および集電体箔から離れ、導電性および集電体との密着性の低下を招く現象を防止することができる。このため、電極、つまり集電体表面に存在する活物質含有層の膜厚を増大させることができ、電池の高エネルギー密度化および高出力密度化が可能となる。
【0015】
本発明では先ず、電極活物質に導電性処理を行うことが必要である。すなわち、電極活物質に導電性を持たせるために、電極化の前に導電助剤、結着剤等を電極活物質表面に密着させるという処理を行う。具体的な処理方法は、結着剤を所定の溶媒中に溶解させた溶液に、導電助剤を分散させ、この溶液を所定の容器内で対流させた電極活物質に噴霧する。
【0016】
溶媒としては、特に限定されるものではなく、導電助剤、結着剤を分散、溶解可能なものであればよく、例えばN−メチル−2−ピロリドン、N,N−ジメチルホルムアミド等を用いることができる。
【0017】
このときの電極活物質のBET比表面積は、好ましくは0.1〜2.0m2/g、より好ましくは0.1〜1.5m2/g、平均粒径は好ましくは1〜20μm、より好ましくは1〜15μmであり、導電処理後の平均粒子径は、好ましくは50〜500μm、より好ましくは50〜300μm程度である。なお、導電処理後の粒子は、複数の導電処理電極活物質を含んだ複合化粒子集合体となっていてもよい。
【0018】
電極活物質に付着する導電助剤、結着剤は、その総計が活物質の3〜15質量%であることが望ましい。
【0019】
上記噴霧処理により、活物質表面への導電助剤、結着剤の付着処理が行われると共に、乾燥が行われる。噴霧処理工程中の雰囲気温度としては50〜100℃程度が好ましい。
【0020】
このようにして得られた導電性粒子を集電体表面に乾式法を用いて担持させる。乾式法としては、導電粒子を集電体と共に、あるいは単体で熱平板プレスや熱ロールに供給し、電極化もしくはシート化する方法等が挙げられる。本発明では特に導電処理された活物質を熱ロールを用いてシート化し、これを集電体表面に接着することが好ましい。集電体への接着方法としては、結着剤を用いて接着することも可能であるが、好ましくは、上記同様乾式法により接着するとよい。具体的には、導電性接着層を有する集電体表面に熱接着するとよい。
【0021】
熱ロールでのシート化の条件としては、用いる結着剤が軟化して接着効果が得られる融点近傍にまで加熱することが好ましい。また、加熱温度の上限としては、結着剤の融点より20℃を超える温度を加えても、結着剤の軟化による接着効果以上の弊害が生じてくることから、結着剤の融点+20℃までが望ましい。また、具体的な加熱温度としては、好ましくは温度:50〜150℃、より好ましくは70〜150℃、さらに好ましくは70〜120℃である。熱ロールの圧力としては、好ましくは線圧:100〜1200kgf/cm、より好ましくは100〜1000kgf/cm程度である。
【0022】
得られた電極活物質シートは、その厚さが好ましくは80〜400μm、より好ましくは80〜300μm程度である。
【0023】
得られた電極シートは、好ましくは導電性接着層を有する集電体に、接着される。この場合、好ましくは導電性接着層は、熱接着性を有し、熱圧着することで接着するようにするとよい。導電性接着層の組成としては、好ましくは前記導電助剤と結着剤を含有するものであるとよい。また、導電性接着層は塗布法により形成するとよい。
【0024】
接着層の組成は、正極では、質量比で導電助剤:結着剤=10〜30:70〜90の範囲が好ましく、負極では、質量比で導電助剤:結着剤=20〜40:60〜80の範囲が好ましい。導電性接着層における導電助剤、結着剤は、上記シート化された活物質含有層と同様なものを用いてもよいが、異なっていてもよい。しかしながら、両者の間で導電性、熱接着性を有する必要があるため、少なくとも結着剤が同種のものであるとよい。また、導電助剤、結着剤の含有量も、活物質含有層と同様なものとしてもよいし、異なっていてもよい。
【0025】
接着層の製造は、まず、導電助剤を、結着剤溶液に分散し、塗布液を調製する。結着剤溶液の溶媒としては特に限定されるものではなく、導電助剤、結着剤を分散、溶解可能なものであればよい。具体的には、上記活物質含有層で挙げたものを用いることができる。
【0026】
そして、この導電性接着層塗布液を集電体に塗布する。塗布する手段は特に限定されず、集電体の材質や形状などに応じて適宜決定すればよい。一般に、メタルマスク印刷法、静電塗装法、ディップコート法、スプレーコート法、ロールコート法、ドクターブレード法、グラビアコート法、スクリーン印刷法等が使用されている。その後、必要に応じて、平板プレス、カレンダーロール等により圧延処理を行う。
【0027】
そして、溶媒を蒸発させ、導電性接着層付き集電体を作製する。塗布厚は、2〜10μm程度とすることが好ましい。
【0028】
得られた導電性接着層付き集電体に、上記活物質層含有シートを接着して電極とする。接着するシートは1層でもよいし、2層以上であってもよい。
【0029】
得られた電極の単位面積あたりの活物質担持量は、好ましくは20mg/cm2以上、特に25mg/cm2以上が好ましい。その上限としては特に限定されるものではないが、通常300mg/cm2程度である。ただし、活物質に炭素系材料を用いる場合には、15mg/cm2以上が好ましい。
【0030】
本発明において、リチウムイオンを吸蔵放出可能な正極活物質は、公知の材料を用いることが可能であるが、好ましくは前記正極の電極活物質が、コバルト酸リチウム、ニッケル酸リチウム、マンガン酸リチウムなどのリチウム含有金属酸化物、またはこれらにAl,Mn,Sn,Fe,Cu,Mg,Ti,Zn,Mo等の金属元素の1種または2種以上が固溶しているリチウム含有複合金属酸化物である。
【0031】
また、より好ましくは下記式で表される複合酸化物材料を用いるとよい。
LixMnyNizCo1−y−zOw
0.85≦x≦1.1、0≦y≦0.6、0≦z≦1、1≦w≦2である。
【0032】
本発明においてリチウムイオンを吸蔵放出可能な負極活物質としては、炭素材料、金属リチウム、リチウム合金あるいは酸化物などが挙げられる。
【0033】
炭素材料では、例えば天然黒鉛、人造黒鉛、メソフェーズカーボンマイクロビーズ(MCMB)、メソフェーズカーボンファイバー(MCF)、コークス類、ガラス状炭素、有機高分子化合物焼成体などが挙げられる。また、リチウム合金ではLi−Al,LiSi,LiSn等が挙げられる。酸化物としては、チタン酸リチウム、Nb2O5、SnO等が挙げられる。これらは通常粉末として用いられる。
【0034】
これらのなかでも特に、格子面(002)面間の面間隔が0.335〜0.380nmの人造黒鉛が好ましい。なお、(002)面間の面間隔はX線回折により算出することができる。天然黒鉛は、不純物により初回の充電時に皮膜を形成する際、その皮膜の質を低下させることがある。人造黒鉛を用いることにより、不純物の影響を回避できるので、イオン透過性の良好な皮膜を形成することができる。
【0035】
これらを粉末で用いる場合、その平均粒子径は1〜30μm、特に5〜25μmであることが好ましい。平均粒子径が小さすぎると、充放電サイクル寿命が短くなり、また、容量のばらつき(個体差)が大きくなる傾向にある。平均粒子径が大きすぎると、容量のばらつきが著しく大きくなり、平均容量が小さくなってしまう。平均粒子径が大きい場合に容量のばらつきが生じるのは、黒鉛等の負極活物質と集電体との接触や負極活物質同士の接触にばらつきが生じるためと考えられる。
【0036】
導電助剤としては、好ましくは黒鉛、カーボンブラック、アセチレンブラック、炭素繊維、ニッケル、アルミニウム、銅、銀等の金属が挙げられ、特に黒鉛、カーボンブラック、アセチレンブラックが好ましい。
【0037】
結着剤としては、スチレンブタジエンゴム(SBR)等のようなエラストマーや、ポリフッ化ビニリデン(PVDF)等のような樹脂材料を用いることができる。また、必要に応じてカルボキシメチルセルロース(CMC)等の添加剤を加えてもよい。
【0038】
集電体は、電池の使用するデバイスの形状やケース内への集電体の配置方法などに応じて、適宜通常の集電体から選択すればよい。一般に、正極にはアルミニウム等が、負極には銅、ニッケル等が使用される。なお、集電体は、通常、金属箔、金属メッシュなどが使用される。金属箔よりも金属メッシュの方が電極との接触抵抗が小さくなるが、金属箔でも十分小さな接触抵抗が得られる。
【0039】
本発明の電極は、活物質含有層が複合化粒子を用いて形成されるものであればよく、それ以外の構造は特に限定されない。また、リチウム二次電池も本発明の電極をアノード及びカソードのうちの少なくとも一方の電極として備えていればよく、それ以外の構成及び構造は特に限定されない。例えば、図4に示すように、集電部材24と活物質含有層22とから構成されるアノード2、同様に集電部材34と活物質含有層32とから構成されるカソード3、およびセパレータを兼ねる電解質層4からなる単位セル102を複数積層し、これを所定のケース9内に密閉した状態で保持させ、パッケージ化したモジュール100の構成を有していてもよい。なお、アノード2、カソード3は、集電部材24,34と活物質含有層22,32との間に接着層を有していてもよい。
【0040】
さらに、この場合、各単位セルを並列に接続してもよく、直列に接続してもよい。また、例えば、このモジュール100を更に直列又は並列に複数電気的に接続させた電池ユニットを構成してもよい。この電池ユニットとしては、例えば、1つのモジュール100のカソード端子と別のモジュール100のアノード端子とが金属片により電気的に接続されることで、直列接続の電池ユニットを構成することができる。
【0041】
さらに、上述のモジュール100や電池ユニットを構成する場合、必要に応じて、既存の電池に備えられているものと同様の保護回路(図示せず)やPTC(図示せず)を更に設けてもよい。
【0042】
リチウム二次電池の構造は特に限定されないが、通常、正極、負極及びセパレータから構成され、積層型電池や巻回型電池等に適用される。このような正極、セパレータ、負極をこの順に積層し、圧着して電極群とする。
【0043】
本発明において、リチウムイオン導電性物質としては、リチウム塩を溶解させた非水電解液やゲル状ポリマーのいずれかを用いることができる。
【0044】
電解液の溶媒としては、高分子固体電解質、電解質塩等との相溶性が良好なものが好ましい。また、リチウム電池等では高い動作電圧でも分解の起こらない極性有機溶媒が望ましい。例えば、エチレンカーボネート(EC)、プロピレンカーボネート(PC)、ブチレンカーボネート、ジメチルカーボネート(DMC)、ジエチルカーボネート(DEC)、エチルメチルカーボネート等のカーボネート類、テトラヒドロフラン(THF)、2−メチルテトラヒドロフラン等の環式エーテル、1,3−ジオキソラン、4−メチルジオキソラン等の環式エーテル、γ−ブチロラクトン等のラクトン、スルホラン等や、3−メチルスルホラン、ジメトキシエタン、ジエトキシエタン、エトキシメトキシエタン、エチルジグライム等を挙げることができる。本発明では、エチレンカーボネート(EC)、プロピレンカーボネート(PC)、ジエチルカーボネート(DEC)、ブチレンカーボネート、特にEC等の環状カーボネートを用いる。
【0045】
リチウムイオンを含む支持塩としては、例えばLiClO4、LiPF6、LiBF4、LiAsF6、LiCF3SO3、LiCF3CF2SO3、LiC(CF3SO2)3、LiN(CF3SO2)2、LiN(CF3CF2SO2)2、LiN(CF3SO2)(C4F9SO2)およびLiN(CF3CF2CO)2などの塩またはこれらの混合物が挙げられる。これらのなかでも、特に6フッ化リン酸リチウム(LiPF6)が好ましい。
【0046】
電解液中のリチウム塩の濃度は1〜3モル/リットルが好ましく、より好ましくは1.0〜2.5モル/リットルである。リチウム塩の濃度がこの範囲より高いと電解液の粘度が高くなり、ハイレートでの放電容量や低温での放電容量が抵下し、低いとリチウムイオンの供給が間に合わなくなり、ハイレートでの放電容量や低温での放電容量が低下する。
【0047】
ゲル状ポリマーとは、例えばポリアクリロニトリル、ポリエチレングリコール、ポリフッ化ビニリデン(PVdF)などに前記リチウム塩を溶解させた非水電解液を膨潤させたものが挙げられる。正極と負極の間の短絡を防止する必要があれば、高分子の多孔膜、例えばポリオレフィン1軸あるいは2軸延伸膜、ポリオレフイン不織布などをセパレータやリチウムイオン導電性ポリマーの基材として用いても良い。
【0048】
ゲル状ポリマーの膜厚は、5〜100μm、さらには5〜60μm、特に10〜40μmであることが好ましい。
【0049】
そのほかのセパレータ構成材料として、ポリエチレン、ポリプロピレンなどのポリオレフイン類の一種又は二種以上(二種以上の場合、二層以上のフィルムの張り合わせ物などがある)、ポリエチレンテレフターレートのようなポリエステル類、エチレン−テトラフルオロエチレン共重合体のような熱可塑性フッ素樹脂類、セルロース類などがある。シートの形態はJIS−P8117に規定する方法で測定した通気度が5〜2000秒/100cc程度、厚さが5〜100μm程度の微多孔膜フィルム、織布、不織布などがある。
【0050】
外装体は、例えばアルミニウム等の金属層の両面に、熱接着性樹脂層としてのポリプロピレン、ポリエチレン等のポリオレフィン樹脂層や耐熱性のポリエステル樹脂層が積層されたラミネートフィルムから構成されている。外装体は、予め2枚のラミネートフィルムをそれらの3辺の端面の熱接着性樹脂層相互を熱接着して第1のシール部を形成し、1辺が開口した袋状に形成される。あるいは、一枚のラミネートフィルムを折り返して両辺の端面を熱接着してシール部を形成して袋状としてもよい。
【0051】
ラミネートフィルムとしては、ラミネートフィルムを構成する金属箔と導出端子間の絶縁を確保するため、例えば内装側から熱接着性樹脂層/ポリエステル樹脂層/金属箔/ポリエステル樹脂層の積層構造を有するラミネートフィルムを用いることが好ましい。このようなラミネートフィルムを用いることにより、熱接着時に高融点のポリエステル樹脂層が溶けずに残るため、導出端子と外装体の金属箔との離間距離を確保し、絶縁を確保することができる。そのため、ラミネートフィルムのポリエステル樹脂層の厚さは、5〜100μm程度とすることが好ましい。
【0052】
本発明は電解液を用いたリチウムイオン電池に関するものであるが、それに限定されることなく、電解質が固体状の電解質である場合にも適用できる。また、外装体も上記で例示されたラミネートタイプのものに限らず、例えば深絞り型等の金属ケースに封入する等してもよい。
【0053】
【実施例】
以下、本発明について実施例を用いて説明する。
〔実施例1〕
A 正極複合化粒子は以下の作製工程により得られた。
正極複合化粒子の作成には,正極活物質として
LixMnyNizCo1−y−zOw
において、x=1,y=0.33,z=0.33,W=2とした複合金属酸化物(90重量%)を用い、導電助剤としてアセチレンブラック(6重量%)、結着剤としてポリフッ化ビニリデン(4重量%)を用いた。複合金属酸化物には導電性を持たせるために、電極化の前にアセチレンブラックおよびポリフッ化ビニリデンを複合金属酸化物表面に密着させるという処理を行った。
【0054】
具体的な処理方法は,ポリフッ化ビニリデンを溶解させたN,N−ジメチルホルム(DMF)溶液にアセチレンブラックを分散させ、この溶液(アセチレンブラック3重量%,ポリフッ化ビニリデン2重量%)を容器内で流動層化させた上記複合金属酸化物粉体に噴霧し付着させるというものである。このときの上記複合金属酸化物粉体のBET比表面積は、0.55m2/g、平均粒径は12μmであり、本実施例の粒子複合化処理により、その複合化粒子集合体の平均径を150μm程度とし、電極化に用いる粒子とした。
【0055】
B 電極は以下の組成および工程により作製した。
上記工程で作製した正極複合化粒子を熱ロールに供給し、電極シート化した。熱ロールの温度は130℃、圧力は線圧300kgf/cmとした。得られた電極シートの正極活物質担持量は60mg/cm2、空孔率は25%であった。電極シートは、熱接着性導電層を有するアルミ箔に熱プレスを用いて200℃、50MPaの条件で電極化した。熱接着性導電層はアルミ箔にポリフッ化ビニリデン(80重量%)、アセチレンブラック(20重量%)のスラリーを5μm厚で塗布したものである。
【0056】
〔実施例2〕
正極活物質担持量を100mg/cm2とした以外は、実施例1と同様にして、導電処理および電極化を行った。
【0057】
〔実施例3〕
正極活物質として、LiCoO2を用い、担持量を60mg/cm2とした以外は、実施例1と同様にして、導電処理および電極化を行った。
【0058】
〔実施例4〕
A 負極複合化粒子は以下の作製工程により得られた。
負極複合化粒子の件成には,負極活物質として人造黒鉛(85重量%)を用い、導電助剤としてアセチレンブラック(5重量%)、結着剤としてポリフッ化ビニリデン(10重量%)を用いた。人造黒鉛には良好な導電性を持たせるために、電極化の前にアセチレンブラックおよびポリフッ化ビニリデンを人造黒鉛表面に密着させるという処理を行った。
【0059】
具体的な処理方法は、ポリフッ化ビニリデンを溶解させたN,N−ジメチルホルム(DMF)溶液にアセチレンブラックを分散させ、この溶液(アセチレンブラック2重量%、ポリフッ化ビニリデン4重量%)を容器内で流動層化させた上記人造黒鉛粉体に噴霧し付着させるというものである。このときの上記人造黒鉛粉体のBET比表面積は、1.0m2/g、平均粒径は30μmであり、本実施例の粒子複合化処理により、複合化粒子集合体の平均径を300μm程度とし、電極化に用いる粒子とした。
【0060】
B 電極は以下の組成および工程により作製した。
上記工程で作製した負極複合化粒子を熱ロールに供給し、電極シート化した。熱ロールの温度は110℃、圧力は線圧100kgf/cmとした。得られた電極シートの負極活物質担持量は32mg/cm2、空孔率は25%であった。電極シートは熱接着性導電層を有する銅箔に熱プレスを用いて100℃、10MPaの条件で電極化した。熱接着性導電層は銅箔にメタクリル酸メチル(70重量%)、アセチレンブラック(30重量%)のスラリーを5μm厚で塗布したものである。
【0061】
〔比較例1〕
実施例1の活物質と導電剤、バインダーを実施例1と同様の組成で混合し、通常の塗布工法により電極として作製した。具体的には活物質と導電剤、バインダーをプラネタリーミル、ホモジナイザーを用いて混合・分散し、スラリーとした後、熱接着性導電層を有するアルミ箔に塗布し、実施例1と同様の活物質担持量・空孔率を有する電極とした。熱導電性接着層は実施例1と同様のものとした。
【0062】
〔比較例2〕
実施例4の活物質と導電剤、バインダーを実施例4と同様の組成で混合し、通常の塗布工法により電極として作製した。具体的には活物質と導電剤、バインダーをプラネタリーミル、ホモジナイザーを用いて混合・分散し、スラリーとした後、熱接着性導電層を有するアルミ箔に塗布し、負極活物質担持量20mg/cm2、空孔率38%を有する電極とした。熱導電性接着層は実施例4と同様のものとした。
【0063】
電極の評価方法は、対極としてリチウム金属を用いて、リチウムイオンと電極との反応を検討した。比較例4の電極として、一般的に用いられている電極を想定して、正極・負極とも比較例1および2で用いている材料・塗布法で作製し、実施例・比較例と比較した。比較例4の電極は正極で活物質担持量15mg/cm2、空孔率30%、負極で活物質担持量8mg/cm2、空孔率35%とした。電流密度は正極が1.6mA/cm2(比較例4の電極:0.2mA/cm2)、負極が1.7mA/cm2(比較例4の電極:0.2mA/cm2)として評価した。
【0064】
正極の放電容量を表1に、負極の放電容量を表2に示す。
【0065】
【表1】
【0066】
【表2】
【0067】
図1に、実施例1−3と比較例1および比較例4(スタンダード)の放電曲線を示した。図1から明らかなように実施例1−3に示した複合化した粒子からなる電極の方が、高出力が得られていることがわかる。電流密度を増加させても過電圧が大きくならないのは、粒子複合化処理によって、電極内部に効果的な導電ネットワークが形成されているためであると考えられる。
【0068】
図2に実施例4と比較例2および比較例4(スタンダード)の放電曲線を示した。図2から明らかなように実施例2に示した複合化した粒子からなる電極の方が、高出力が得られていることがわかる。電流密度を増加させても過電圧が大きくならないのは、粒子複合化処理によって、電極内部に効果的な導電ネットワークが形成されているためであると考えられる。
【0069】
〔実施例5〕
実施例1および4で作製した電極を用いて電池を作製した。電池は、前記正極と負極をセパレータを介して積層してセル化し、アルミラミネートフィルム外装体内に収納した後、電解液を注液して、得た。電解液には体積比でEC/DEC=3/7とした混合溶液を溶媒とし、LiPF6を1 mol/Lの割合で溶質とした非水電解溶液を用いた。電池の厚みは3.9mmであった。
【0070】
〔比較例3〕
前記比較例4の正極と比較例4の負極を用いた以外は実施例5と同様にして電池を作製した。電池の厚みは3.8mmであった。
【0071】
これら電池の放電特性を表3に示す。また、実施例5の電池の放電特性を図3に示す。
【0072】
【表3】
【0073】
表3から明らかなように、電極内に効果的な導電ネットワークを形成させた電極を用いることで、電池の高エネルギー密度を達成することが可能であることが分かる。なお、比較例1,2と同様の構成で電極を作製し、電池を構成することを試みたが、電極層と集電体との密着性に問題があり、素子化を断念せざるを得なかった。
【0074】
以上の結果から本発明によれば、良好な導電性を持つ厚膜電極の作成が可能となり、高エネルギー密度電池および高出力密度電池を得ることができる。さらに乾式法での電極作成となるため、電極作成の際に有機溶剤が不要となり、工程の簡素化につながる。また、本発明で実施した電極活物質への導電処理が極めて有効なものであるために、導電助剤の添加量を従来よりも削減でき、それによっても高エネルギー密度化や高い導電性から得られる高出力密度化などが可能となる。
【0075】
【発明の効果】
以上のように本発明によれば、さらなる高エネルギー密度化および高出力密度化を可能とし、用途の拡大に寄与できるリチウム二次電池を提供することができる。
【図面の簡単な説明】
【図1】実施例1−3と比較例1および比較例4(スタンダード)の放電曲線を示したグラフである。
【図2】実施例4と比較例2および比較例4(スタンダード)の放電曲線を示したグラフである。
【図3】実施例5の電池の放電特性を示すグラフである。
【図4】本発明の一形態であるリチウム二次電池の基本構成を示す概略断面図である。
【符号の説明】
2 アノード
3 カソード
4 電解質層
9 ケース
22、32 活物質含有層
24、34 集電部材
100 モジュール
102 単位セル[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lithium secondary battery used as a power source of a portable device.
[0002]
[Prior art]
Lithium ion secondary batteries have been widely used as power sources for portable devices in terms of high output batteries. Lithium-ion secondary batteries have been on the market for more than a decade, and their characteristics have been improved. Regarding lithium ion secondary batteries, high capacity and high safety are emphasized as technical issues.
[0003]
Conventionally, in a lithium ion secondary battery, an electrode is manufactured by dispersing an electrode active material, a binder, and, if necessary, a conductive assistant in a binder solution to form a slurry, and then forming a metal as a current collector. It is performed by applying it to a foil or the like. The electrode is added with a conductive additive as necessary, and as a material thereof, usually, a metal such as graphite, carbon black, acetylene black, carbon fiber, nickel, aluminum, copper, or silver is used. Black and acetylene black are used.
[0004]
As a positive electrode active material of a lithium ion secondary battery, there are usually lithium-containing metal oxides such as lithium cobalt oxide, lithium nickel oxide, lithium manganate and the like, which are substances capable of inserting and extracting lithium ions in the structure. A lithium-containing composite metal oxide to which at least one metal element such as aluminum, manganese, tin, iron, copper, magnesium, titanium, zinc, and molybdenum is added is used.
[0005]
However, since these metal oxides have poor electron conductivity, a conductive assistant is required for use as an electrode of a lithium ion secondary battery.
[0006]
As the conductive assistant, carbon black and acetylene black which form a good conductive network are preferably used. When these are used as the conductive assistant of the positive electrode, the conductive assistant is dispersed in a binder solution together with the active material to form a paint, and applied to a metal foil as a current collector, for example, an aluminum foil, and then dried and rolled. To form an electrode.
[0007]
However, when the electrode is dried, carbon black, acetylene black, and the binder have a low specific gravity, and as the solvent used as a solvent evaporates, the carbon material floats up to near the surface of the coating film. In addition, a problem arises in a good conductive path obtained from the close contact of the binder and the close contact between the current collector and the active material. This effect becomes more pronounced as the electrode thickness increases. For this reason, in the conventional positive electrode, the amount of the positive electrode active material carried per unit area is 20 mg / cm.2This must be kept below, which hinders further increase in energy density and output of the lithium ion secondary battery.
[0008]
In the conventional method of forming an electrode by a wet method, the conductive assistant and the binder are separated from the current collector foil during drying after the application of the electrode, resulting in a decrease in conductivity and adhesion to the current collector. This phenomenon becomes remarkable particularly when an electrode active material having poor electron conductivity is used and a thick-film electrode is formed, and this is a very serious obstacle to exhibiting battery characteristics. Specifically, the positive electrode active material described above was used for the positive electrode of the lithium ion secondary battery, and the amount of active material carried per unit area was 20 mg / cm.2It becomes remarkable when the above positive electrode is used, and is 30 mg / cm2With the above supported amount, the battery characteristics are reduced to a level that is not practically used.
[0009]
The same applies to the case where a thick film electrode is used, for example, when a carbon material capable of inserting and extracting lithium ions or a titanium-based oxide is used as a negative electrode active material, or when a vanadium-based oxide is used as a positive electrode active material. is there. To solve these problems, better conductive paths had to be built in the electrode material than conventional electrodes.
[0010]
[Problems to be solved by the present invention]
An object of the present invention is to provide a lithium secondary battery that solves the above problems, enables higher energy density and higher output density, and can contribute to expansion of applications.
[0011]
[Means for Solving the Problems]
That is, the above object is achieved by the following configuration of the present invention.
(1) Positive and negative electrodes having an electrode active material capable of inserting and extracting at least lithium ions, a binder, and a current collector, and an electrolytic solution,
An electrode active material contained in at least one of the positive electrode and the negative electrode is subjected to a conductive treatment by coating a surface with a conductive additive and a binder, and the electrode active material is collected by a dry method. A lithium secondary battery carried on the body surface.
(2) The lithium secondary battery according to (1), wherein the active material-containing layer subjected to the conductive treatment is formed into a sheet and bonded to a current collector having a conductive adhesive layer.
(3) The lithium secondary battery according to (2), wherein the conductive adhesive layer contains at least a conductive assistant and a binder, and is formed by a coating method.
(4) The active material carrying amount per unit area of the electrode is 20 mg / cm.2The lithium secondary battery according to any one of the above (1) to (3).
(5) The active material of the electrode is a carbon-based material, and the active material carrying amount per unit area of the electrode is 15 mg / cm.2The lithium secondary battery according to any one of the above (1) to (3).
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The lithium secondary battery of the present invention has at least an electrode active material capable of inserting and extracting lithium ions, a binder, a positive electrode and a negative electrode having a current collector, and an electrolytic solution. An electrode active material contained in at least one of the electrodes is subjected to a conductive treatment by coating the surface with a conductive auxiliary and a binder, and the electrode active material is carried on the current collector surface by a dry method. Is what it is.
[0013]
The present invention builds an effective conductive network in the active material-containing layer in the electrode, increases the amount of active material carried per unit area, and makes the electrode a thick film, thereby reducing the energy density and output density of the battery. It is about raising. For that purpose, it is necessary to give the electrode active material better conductivity than before. In this regard, a treatment for imparting conductivity to the surface of the electrode active material is necessary, and specifically, it can be solved by performing a complexing treatment for the purpose of bringing the conductive aid and the binder into close contact with the active material surface. . Then, the obtained electrode material is converted into an electrode by a dry method, and a target high energy density battery and a high output density battery are obtained.
[0014]
That is, by performing the treatment by the dry method, the conductive assistant and the binder separate from the active material and the current collector foil at the time of drying after the conventional electrode coating, which causes a decrease in conductivity and adhesion with the current collector. The phenomenon can be prevented. Therefore, the thickness of the electrode, that is, the active material-containing layer existing on the surface of the current collector can be increased, and the energy density and the output density of the battery can be increased.
[0015]
In the present invention, first, it is necessary to perform a conductive treatment on the electrode active material. That is, in order to impart conductivity to the electrode active material, a process is performed in which a conductive auxiliary agent, a binder, and the like are brought into close contact with the surface of the electrode active material before forming the electrode. As a specific treatment method, a conductive additive is dispersed in a solution in which a binder is dissolved in a predetermined solvent, and this solution is sprayed on the electrode active material convected in a predetermined container.
[0016]
The solvent is not particularly limited as long as it can disperse and dissolve the conductive assistant and the binder. For example, N-methyl-2-pyrrolidone, N, N-dimethylformamide and the like can be used. Can be.
[0017]
The BET specific surface area of the electrode active material at this time is preferably 0.1 to 2.0 m2/ G, more preferably 0.1 to 1.5 m2/ G, the average particle diameter is preferably 1 to 20 μm, more preferably 1 to 15 μm, and the average particle diameter after the conductive treatment is preferably about 50 to 500 μm, more preferably about 50 to 300 μm. Note that the particles after the conductive treatment may be a composite particle aggregate including a plurality of conductive treatment electrode active materials.
[0018]
It is desirable that the total amount of the conductive auxiliary agent and the binder attached to the electrode active material is 3 to 15% by mass of the active material.
[0019]
By the above-mentioned spraying process, the conductive auxiliary agent and the binder are attached to the surface of the active material, and drying is performed. The ambient temperature during the spraying process is preferably about 50 to 100 ° C.
[0020]
The conductive particles thus obtained are supported on the surface of the current collector by a dry method. Examples of the dry method include a method in which conductive particles are supplied together with a current collector or alone to a hot plate press or a hot roll to form electrodes or sheets. In the present invention, it is particularly preferable that the active material subjected to the conductive treatment is formed into a sheet using a hot roll, and the sheet is adhered to the current collector surface. As a method of bonding to the current collector, it is possible to bond using a binder, but it is preferable to bond by a dry method as described above. Specifically, it is preferable to thermally bond to the surface of the current collector having the conductive adhesive layer.
[0021]
As a condition for forming a sheet with a heat roll, it is preferable to heat the binder to a temperature close to a melting point at which the binder used is softened and an adhesive effect is obtained. Further, as the upper limit of the heating temperature, even if a temperature exceeding 20 ° C. from the melting point of the binder is added, adverse effects beyond the adhesive effect due to the softening of the binder occur, so that the melting point of the binder + 20 ° C. Is desirable. The specific heating temperature is preferably 50 to 150 ° C, more preferably 70 to 150 ° C, and even more preferably 70 to 120 ° C. The pressure of the hot roll is preferably about 100 to 1200 kgf / cm, more preferably about 100 to 1000 kgf / cm.
[0022]
The thickness of the obtained electrode active material sheet is preferably about 80 to 400 μm, and more preferably about 80 to 300 μm.
[0023]
The obtained electrode sheet is preferably bonded to a current collector having a conductive adhesive layer. In this case, preferably, the conductive adhesive layer has thermal adhesiveness, and is preferably bonded by thermocompression bonding. The composition of the conductive adhesive layer preferably contains the above-mentioned conductive assistant and a binder. Further, the conductive adhesive layer is preferably formed by a coating method.
[0024]
In the positive electrode, the composition of the adhesive layer is preferably in the range of conductive auxiliary agent: binder = 10 to 30:70 to 90 by mass ratio, and in the negative electrode, the conductive auxiliary agent: binder = 20 to 40: by mass ratio. A range from 60 to 80 is preferred. The conductive auxiliary agent and the binder in the conductive adhesive layer may be the same as the active material-containing layer formed into the sheet, or may be different. However, since it is necessary to have conductivity and thermal adhesiveness between the two, at least the binder is preferably of the same type. Further, the contents of the conductive assistant and the binder may be the same as or different from those of the active material-containing layer.
[0025]
In the production of the adhesive layer, first, a conductive aid is dispersed in a binder solution to prepare a coating solution. The solvent of the binder solution is not particularly limited, and may be any solvent that can disperse and dissolve the conductive additive and the binder. Specifically, those described in the above active material-containing layer can be used.
[0026]
Then, the conductive adhesive layer coating solution is applied to the current collector. The means for applying is not particularly limited, and may be appropriately determined according to the material and shape of the current collector. Generally, a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a gravure coating method, a screen printing method, and the like are used. Thereafter, if necessary, a rolling treatment is performed by a flat plate press, a calender roll, or the like.
[0027]
Then, the solvent is evaporated to produce a current collector with a conductive adhesive layer. The coating thickness is preferably about 2 to 10 μm.
[0028]
The above-mentioned active material layer-containing sheet is bonded to the obtained current collector with a conductive adhesive layer to form an electrode. The sheet to be bonded may be a single layer or two or more layers.
[0029]
The amount of the active material carried per unit area of the obtained electrode is preferably 20 mg / cm.2Above, especially 25 mg / cm2The above is preferable. Although the upper limit is not particularly limited, it is usually 300 mg / cm.2It is about. However, when a carbon-based material is used as the active material, 15 mg / cm2The above is preferable.
[0030]
In the present invention, as the positive electrode active material capable of inserting and extracting lithium ions, a known material can be used. Preferably, the positive electrode active material is lithium cobaltate, lithium nickelate, lithium manganate, or the like. Or a lithium-containing composite metal oxide in which one or more of metal elements such as Al, Mn, Sn, Fe, Cu, Mg, Ti, Zn, and Mo are dissolved as a solid solution It is.
[0031]
Further, a composite oxide material represented by the following formula is more preferably used.
LixMnyNizCo1-yzOw
0.85 ≦ x ≦ 1.1, 0 ≦ y ≦ 0.6, 0 ≦ z ≦ 1, 1 ≦ w ≦ 2.
[0032]
In the present invention, examples of the negative electrode active material capable of inserting and extracting lithium ions include carbon materials, metallic lithium, lithium alloys and oxides.
[0033]
Examples of the carbon material include natural graphite, artificial graphite, mesophase carbon microbeads (MCMB), mesophase carbon fiber (MCF), cokes, glassy carbon, and a fired organic polymer compound. Examples of the lithium alloy include Li-Al, LiSi, and LiSn. As the oxide, lithium titanate, Nb2O5, SnO and the like. These are usually used as powders.
[0034]
Of these, artificial graphite having a lattice spacing between lattice (002) planes of 0.335 to 0.380 nm is particularly preferred. The plane spacing between the (002) planes can be calculated by X-ray diffraction. When natural graphite forms a film during the first charge due to impurities, the quality of the film may be degraded. By using artificial graphite, the influence of impurities can be avoided, so that a film having good ion permeability can be formed.
[0035]
When these are used as powders, the average particle diameter is preferably 1 to 30 μm, particularly preferably 5 to 25 μm. If the average particle size is too small, the charge / discharge cycle life tends to be short and the variation in capacity (individual difference) tends to be large. If the average particle size is too large, the dispersion of the capacity becomes extremely large, and the average capacity becomes small. It is considered that the variation in capacity occurs when the average particle diameter is large because variations occur in the contact between the negative electrode active material such as graphite and the current collector and the contact between the negative electrode active materials.
[0036]
Examples of the conductive aid include graphite, carbon black, acetylene black, carbon fiber, and metals such as nickel, aluminum, copper, and silver. Graphite, carbon black, and acetylene black are particularly preferable.
[0037]
As the binder, an elastomer such as styrene-butadiene rubber (SBR) or a resin material such as polyvinylidene fluoride (PVDF) can be used. Further, an additive such as carboxymethyl cellulose (CMC) may be added as necessary.
[0038]
The current collector may be appropriately selected from ordinary current collectors according to the shape of the device used by the battery, the method of disposing the current collector in the case, and the like. Generally, aluminum or the like is used for the positive electrode, and copper, nickel, or the like is used for the negative electrode. Note that a metal foil, a metal mesh, or the like is generally used as the current collector. Although the metal mesh has a smaller contact resistance with the electrode than the metal foil, a sufficiently small contact resistance can be obtained with the metal foil.
[0039]
The electrode of the present invention is not particularly limited as long as the active material-containing layer is formed using composite particles, and other structures are not particularly limited. Further, the lithium secondary battery may be provided with the electrode of the present invention as at least one of the anode and the cathode, and other configurations and structures are not particularly limited. For example, as shown in FIG. 4, the anode 2 composed of the current collecting
[0040]
Further, in this case, the unit cells may be connected in parallel or in series. Further, for example, a battery unit in which a plurality of the
[0041]
Further, when configuring the above-described
[0042]
Although the structure of the lithium secondary battery is not particularly limited, it is generally composed of a positive electrode, a negative electrode, and a separator, and is applied to a stacked battery, a wound battery, and the like. Such a positive electrode, a separator, and a negative electrode are laminated in this order, and pressed to form an electrode group.
[0043]
In the present invention, as the lithium ion conductive substance, any of a non-aqueous electrolyte solution in which a lithium salt is dissolved and a gel polymer can be used.
[0044]
As the solvent for the electrolytic solution, those having good compatibility with the solid polymer electrolyte, the electrolyte salt, and the like are preferable. Further, in a lithium battery or the like, a polar organic solvent which does not cause decomposition even at a high operating voltage is desirable. For example, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, dimethyl carbonate (DMC), diethyl carbonate (DEC), carbonates such as ethyl methyl carbonate, and cyclic compounds such as tetrahydrofuran (THF) and 2-methyltetrahydrofuran Cyclic ethers such as ether, 1,3-dioxolan, and 4-methyldioxolan; lactones such as γ-butyrolactone; sulfolane; and 3-methylsulfolane, dimethoxyethane, diethoxyethane, ethoxymethoxyethane, and ethyldiglyme. Can be mentioned. In the present invention, a cyclic carbonate such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), butylene carbonate, and particularly EC is used.
[0045]
As a supporting salt containing lithium ions, for example, LiClO4, LiPF6, LiBF4, LiAsF6, LiCF3SO3, LiCF3CF2SO3, LiC (CF3SO2)3, LiN (CF3SO2)2, LiN (CF3CF2SO2)2, LiN (CF3SO2) (C4F9SO2) And LiN (CF3CF2CO)2And mixtures thereof. Among these, especially lithium hexafluorophosphate (LiPF)6Is preferred.
[0046]
The concentration of the lithium salt in the electrolytic solution is preferably 1 to 3 mol / l, more preferably 1.0 to 2.5 mol / l. If the concentration of the lithium salt is higher than this range, the viscosity of the electrolytic solution becomes high, and the discharge capacity at a high rate and the discharge capacity at a low temperature are reduced.If the concentration is low, supply of lithium ions cannot be performed in time, and the discharge capacity at a high rate and The discharge capacity at low temperatures decreases.
[0047]
Examples of the gel polymer include those obtained by swelling a non-aqueous electrolyte obtained by dissolving the lithium salt in polyacrylonitrile, polyethylene glycol, polyvinylidene fluoride (PVdF), or the like. If it is necessary to prevent a short circuit between the positive electrode and the negative electrode, a polymer porous film, such as a polyolefin uniaxial or biaxially stretched film, a polyolefin nonwoven fabric, or the like may be used as a separator or a base material of a lithium ion conductive polymer. .
[0048]
The thickness of the gel polymer is preferably 5 to 100 μm, more preferably 5 to 60 μm, and particularly preferably 10 to 40 μm.
[0049]
As other separator constituent materials, one or two or more of polyolefins such as polyethylene and polypropylene (in the case of two or more, there are laminated films of two or more layers), polyesters such as polyethylene terephthalate, There are thermoplastic fluororesins such as ethylene-tetrafluoroethylene copolymer, celluloses and the like. Examples of the form of the sheet include a microporous film having a permeability of about 5 to 2000 sec / 100 cc and a thickness of about 5 to 100 μm, a woven fabric, and a nonwoven fabric, as measured by the method specified in JIS-P8117.
[0050]
The exterior body is composed of a laminated film in which a polyolefin resin layer such as polypropylene or polyethylene as a heat-adhesive resin layer or a heat-resistant polyester resin layer is laminated on both surfaces of a metal layer such as aluminum. The exterior body is formed in a bag shape with one side opened by previously bonding two laminated films to each other by thermally bonding the thermo-adhesive resin layers on the end faces of the three sides to each other. Alternatively, a single laminated film may be folded back, and the end surfaces of both sides may be thermally bonded to form a seal portion to form a bag.
[0051]
As the laminate film, a laminate film having a laminated structure of, for example, a heat-adhesive resin layer / polyester resin layer / metal foil / polyester resin layer from the interior side in order to ensure insulation between the metal foil constituting the laminate film and the lead terminals. It is preferable to use By using such a laminate film, the polyester resin layer having a high melting point remains without melting at the time of thermal bonding, so that a separation distance between the lead terminal and the metal foil of the exterior body can be secured, and insulation can be secured. Therefore, it is preferable that the thickness of the polyester resin layer of the laminate film is about 5 to 100 μm.
[0052]
The present invention relates to a lithium ion battery using an electrolytic solution, but is not limited thereto, and can be applied to a case where the electrolyte is a solid electrolyte. Further, the exterior body is not limited to the laminate type exemplified above, but may be enclosed in a metal case such as a deep drawing type.
[0053]
【Example】
Hereinafter, the present invention will be described using examples.
[Example 1]
A Positive electrode composite particles were obtained by the following production steps.
For the preparation of composite particles for the positive electrode, use as a positive electrode active material
LixMnyNizCo1-yzOw
In the above, a composite metal oxide (90% by weight) in which x = 1, y = 0.33, z = 0.33, and W = 2 was used, acetylene black (6% by weight) as a conductive aid, and a binder Used was polyvinylidene fluoride (4% by weight). In order to impart conductivity to the composite metal oxide, a treatment was performed in which acetylene black and polyvinylidene fluoride were brought into close contact with the surface of the composite metal oxide before forming the electrode.
[0054]
As a specific treatment method, acetylene black is dispersed in an N, N-dimethylform (DMF) solution in which polyvinylidene fluoride is dissolved, and this solution (acetylene black 3% by weight, polyvinylidene fluoride 2% by weight) is placed in a container. Is sprayed and adhered to the composite metal oxide powder fluidized. At this time, the BET specific surface area of the composite metal oxide powder was 0.55 m2/ G, the average particle diameter is 12 μm, and the average particle diameter of the composite particle aggregate is set to about 150 μm by the particle composite treatment of the present example to obtain particles used for electrode formation.
[0055]
The B electrode was manufactured by the following composition and process.
The composite positive electrode particles produced in the above steps were supplied to a hot roll to form an electrode sheet. The temperature of the hot roll was 130 ° C., and the pressure was 300 kgf / cm of linear pressure. The positive electrode active material carrying amount of the obtained electrode sheet was 60 mg / cm.2And the porosity was 25%. The electrode sheet was formed into an electrode at 200 ° C. and 50 MPa by using a hot press on an aluminum foil having a heat-adhesive conductive layer. The thermally adhesive conductive layer is formed by applying a slurry of polyvinylidene fluoride (80% by weight) and acetylene black (20% by weight) to a thickness of 5 μm on an aluminum foil.
[0056]
[Example 2]
100 mg / cm2A conductive treatment and electrode formation were carried out in the same manner as in Example 1 except that the above-mentioned conditions were adopted.
[0057]
[Example 3]
LiCoO as a positive electrode active material2And the loading amount is 60 mg / cm2A conductive treatment and electrode formation were carried out in the same manner as in Example 1 except that the above-mentioned conditions were adopted.
[0058]
[Example 4]
A Negative electrode composite particles were obtained by the following production steps.
In forming the negative electrode composite particles, artificial graphite (85% by weight) was used as a negative electrode active material, acetylene black (5% by weight) was used as a conductive additive, and polyvinylidene fluoride (10% by weight) was used as a binder. Was. In order to impart good conductivity to the artificial graphite, a treatment was performed in which acetylene black and polyvinylidene fluoride were brought into close contact with the surface of the artificial graphite before the electrodes were formed.
[0059]
As a specific treatment method, acetylene black is dispersed in an N, N-dimethylform (DMF) solution in which polyvinylidene fluoride is dissolved, and this solution (acetylene black 2% by weight,
[0060]
The B electrode was manufactured by the following composition and process.
The negative electrode composite particles produced in the above step were supplied to a hot roll to form an electrode sheet. The temperature of the hot roll was 110 ° C., and the pressure was 100 kgf / cm of linear pressure. The negative electrode active material carrying amount of the obtained electrode sheet was 32 mg / cm.2And the porosity was 25%. The electrode sheet was formed into an electrode at 100 ° C. and 10 MPa using a hot press on a copper foil having a heat-adhesive conductive layer. The thermoadhesive conductive layer is formed by applying a slurry of methyl methacrylate (70% by weight) and acetylene black (30% by weight) to a thickness of 5 μm on a copper foil.
[0061]
[Comparative Example 1]
The active material, the conductive agent, and the binder of Example 1 were mixed with the same composition as in Example 1, and fabricated as an electrode by a normal coating method. Specifically, the active material, the conductive agent, and the binder were mixed and dispersed using a planetary mill and a homogenizer to form a slurry, which was then applied to an aluminum foil having a heat-adhesive conductive layer. The electrode had a substance carrying amount and a porosity. The heat conductive adhesive layer was the same as in Example 1.
[0062]
[Comparative Example 2]
The active material, the conductive agent, and the binder of Example 4 were mixed with the same composition as in Example 4, and fabricated as an electrode by a normal coating method. Specifically, the active material, the conductive agent, and the binder are mixed and dispersed using a planetary mill and a homogenizer to form a slurry, and then the slurry is applied to an aluminum foil having a heat-adhesive conductive layer. cm2And an electrode having a porosity of 38%. The heat conductive adhesive layer was the same as in Example 4.
[0063]
The electrode was evaluated by using lithium metal as a counter electrode and examining the reaction between lithium ions and the electrode. Assuming a commonly used electrode as the electrode of Comparative Example 4, both the positive electrode and the negative electrode were manufactured using the materials and coating methods used in Comparative Examples 1 and 2, and compared with Examples and Comparative Examples. The electrode of Comparative Example 4 was a positive electrode and the active material carrying amount was 15 mg / cm.2, Porosity 30%, active material carrying amount 8 mg / cm on negative electrode2And a porosity of 35%. The current density of the positive electrode was 1.6 mA / cm.2(Electrode of Comparative Example 4: 0.2 mA / cm2), 1.7 mA / cm negative electrode2(Electrode of Comparative Example 4: 0.2 mA / cm2).
[0064]
Table 1 shows the discharge capacity of the positive electrode, and Table 2 shows the discharge capacity of the negative electrode.
[0065]
[Table 1]
[0066]
[Table 2]
[0067]
FIG. 1 shows the discharge curves of Example 1-3, Comparative Example 1, and Comparative Example 4 (standard). As is clear from FIG. 1, it is understood that the electrode composed of the composite particles shown in Example 1-3 has higher output. It is considered that the reason why the overvoltage does not increase even when the current density is increased is that an effective conductive network is formed inside the electrode by the particle composite processing.
[0068]
FIG. 2 shows the discharge curves of Example 4, Comparative Example 2 and Comparative Example 4 (standard). As is clear from FIG. 2, it is understood that the electrode composed of the composite particles shown in Example 2 has higher output. It is considered that the reason why the overvoltage does not increase even when the current density is increased is that an effective conductive network is formed inside the electrode by the particle composite processing.
[0069]
[Example 5]
A battery was produced using the electrodes produced in Examples 1 and 4. The battery was obtained by laminating the positive electrode and the negative electrode via a separator to form a cell, storing the cell in an aluminum laminate film package, and then injecting an electrolytic solution. The mixed solution of EC / DEC = 3/7 by volume was used as a solvent for the electrolyte, and LiPF6Was used as a solute at a rate of 1 mol / L. The thickness of the battery was 3.9 mm.
[0070]
[Comparative Example 3]
A battery was fabricated in the same manner as in Example 5, except that the positive electrode of Comparative Example 4 and the negative electrode of Comparative Example 4 were used. The thickness of the battery was 3.8 mm.
[0071]
Table 3 shows the discharge characteristics of these batteries. FIG. 3 shows the discharge characteristics of the battery of Example 5.
[0072]
[Table 3]
[0073]
As is clear from Table 3, it is understood that a high energy density of the battery can be achieved by using an electrode having an effective conductive network formed in the electrode. Although an attempt was made to form a battery by forming an electrode in the same configuration as in Comparative Examples 1 and 2, there was a problem in the adhesion between the electrode layer and the current collector, and the device had to be abandoned. Did not.
[0074]
From the above results, according to the present invention, a thick-film electrode having good conductivity can be produced, and a high energy density battery and a high output density battery can be obtained. Further, since the electrodes are formed by a dry method, an organic solvent is not required at the time of forming the electrodes, which leads to simplification of the process. In addition, since the conductive treatment of the electrode active material performed in the present invention is extremely effective, the amount of the conductive additive added can be reduced as compared with the conventional case, thereby achieving higher energy density and higher conductivity. High output density can be achieved.
[0075]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a lithium secondary battery capable of further increasing the energy density and the output density and contributing to the expansion of applications.
[Brief description of the drawings]
FIG. 1 is a graph showing discharge curves of Example 1-3, Comparative Example 1, and Comparative Example 4 (standard).
FIG. 2 is a graph showing discharge curves of Example 4, Comparative Example 2, and Comparative Example 4 (standard).
FIG. 3 is a graph showing discharge characteristics of the battery of Example 5.
FIG. 4 is a schematic cross-sectional view illustrating a basic configuration of a lithium secondary battery which is one embodiment of the present invention.
[Explanation of symbols]
2 anode
3 cathode
4 Electrolyte layer
9 case
22, 32% active material-containing layer
24, 34 current collecting member
100mm module
102 unit cell
Claims (5)
前記正極または負極の少なくともいずれかの電極に含まれる電極活物質が、その表面に導電助剤と、結着剤とを被覆させることで導電処理され、かつこの電極活物質が乾式法で集電体表面に担持されているリチウム二次電池。An electrode active material capable of inserting and extracting at least lithium ions, a binder, a positive electrode and a negative electrode having a current collector, and an electrolytic solution,
An electrode active material contained in at least one of the positive electrode and the negative electrode is subjected to a conductive treatment by coating a surface with a conductive additive and a binder, and the electrode active material is collected by a dry method. A lithium secondary battery carried on the body surface.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003090641A JP4561041B2 (en) | 2002-03-28 | 2003-03-28 | Lithium secondary battery |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002091676 | 2002-03-28 | ||
JP2003090641A JP4561041B2 (en) | 2002-03-28 | 2003-03-28 | Lithium secondary battery |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2004006285A true JP2004006285A (en) | 2004-01-08 |
JP4561041B2 JP4561041B2 (en) | 2010-10-13 |
Family
ID=30446238
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2003090641A Expired - Fee Related JP4561041B2 (en) | 2002-03-28 | 2003-03-28 | Lithium secondary battery |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP4561041B2 (en) |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005243447A (en) * | 2004-02-26 | 2005-09-08 | Jfe Chemical Corp | Negative electrode material for lithium ion secondary battery, negative electrode and lithium ion secondary battery |
JP2005276609A (en) * | 2004-03-24 | 2005-10-06 | Tdk Corp | Composite particle for electrode, electrode, electrochemical element, and manufacturing methods for them |
JP2006216395A (en) * | 2005-02-04 | 2006-08-17 | Tdk Corp | Lithium ion battery pack |
JP2009206079A (en) * | 2008-01-30 | 2009-09-10 | Panasonic Corp | Nonaqueous secondary battery and method for producing the same |
JP2010123580A (en) * | 2010-02-03 | 2010-06-03 | Sharp Corp | Lithium secondary battery |
JP2016514356A (en) * | 2013-03-12 | 2016-05-19 | エネヴェート・コーポレーション | Electrode, electrochemical cell, and method for forming electrode and electrochemical cell |
WO2016152860A1 (en) * | 2015-03-24 | 2016-09-29 | 日本電気株式会社 | Lithium ion secondary battery and method for manufacturing same |
JPWO2017090242A1 (en) * | 2015-11-27 | 2018-09-13 | 日本ゼオン株式会社 | Non-aqueous secondary battery adhesive layer composition, non-aqueous secondary battery adhesive layer, and non-aqueous secondary battery |
US10388943B2 (en) | 2010-12-22 | 2019-08-20 | Enevate Corporation | Methods of reducing occurrences of short circuits and/or lithium plating in batteries |
US10431808B2 (en) | 2010-12-22 | 2019-10-01 | Enevate Corporation | Electrodes, electrochemical cells, and methods of forming electrodes and electrochemical cells |
US10686214B2 (en) | 2017-12-07 | 2020-06-16 | Enevate Corporation | Sandwich electrodes and methods of making the same |
US11133498B2 (en) | 2017-12-07 | 2021-09-28 | Enevate Corporation | Binding agents for electrochemically active materials and methods of forming the same |
JP2022013199A (en) * | 2020-07-03 | 2022-01-18 | トヨタ自動車株式会社 | Electrode structure body |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02204962A (en) * | 1989-02-01 | 1990-08-14 | Fuji Elelctrochem Co Ltd | Current collector jointing method for sheet type positive electrode black mixture |
JPH07194989A (en) * | 1995-01-17 | 1995-08-01 | Marumasu Kikai Kk | One time cleaning rice polisher |
JPH0935705A (en) * | 1995-07-17 | 1997-02-07 | Matsushita Electric Ind Co Ltd | Polymer electrolyte-lithium battery and manufacture of its electrode |
JPH09283115A (en) * | 1996-04-11 | 1997-10-31 | Sumitomo Electric Ind Ltd | Nonaqueous electrolyte secondary battery and manufacture of its electrode |
JPH10106564A (en) * | 1996-09-30 | 1998-04-24 | Sharp Corp | Manufacture of positive electrode active material lithium nickelate for nonaqueous secondary battery, and nonaqueous secondary battery |
JPH11144710A (en) * | 1997-11-04 | 1999-05-28 | Tdk Corp | Electrode structure for electrochemical element |
JPH11265716A (en) * | 1998-03-16 | 1999-09-28 | Denso Corp | Negative electrode active material for lithium secondary battery and its manufacture |
JPH11297332A (en) * | 1998-04-13 | 1999-10-29 | Tdk Corp | Current collector and sheet type electrochemical element using the same |
JP2000106183A (en) * | 1999-10-14 | 2000-04-11 | Hitachi Ltd | Non-aqueous secondary battery and manufacture of graphite powder |
JP2000123876A (en) * | 1998-10-13 | 2000-04-28 | Hosokawa Micron Corp | Manufacture of lithium ion battery material |
JP2001155777A (en) * | 1999-11-26 | 2001-06-08 | Kyocera Corp | Lithium battery |
JP2001185126A (en) * | 1999-12-22 | 2001-07-06 | Kyocera Corp | Lithium secondary battery and manufacturing method thereof |
JP2002008657A (en) * | 2000-06-23 | 2002-01-11 | Asahi Glass Co Ltd | Negative electrode material for secondary power source, manufacturing method of secondary power source and negative electrode material |
JP2002042787A (en) * | 2000-07-28 | 2002-02-08 | Matsushita Electric Ind Co Ltd | Lithium secondary battery and manufacturing method for it |
-
2003
- 2003-03-28 JP JP2003090641A patent/JP4561041B2/en not_active Expired - Fee Related
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02204962A (en) * | 1989-02-01 | 1990-08-14 | Fuji Elelctrochem Co Ltd | Current collector jointing method for sheet type positive electrode black mixture |
JPH07194989A (en) * | 1995-01-17 | 1995-08-01 | Marumasu Kikai Kk | One time cleaning rice polisher |
JPH0935705A (en) * | 1995-07-17 | 1997-02-07 | Matsushita Electric Ind Co Ltd | Polymer electrolyte-lithium battery and manufacture of its electrode |
JPH09283115A (en) * | 1996-04-11 | 1997-10-31 | Sumitomo Electric Ind Ltd | Nonaqueous electrolyte secondary battery and manufacture of its electrode |
JPH10106564A (en) * | 1996-09-30 | 1998-04-24 | Sharp Corp | Manufacture of positive electrode active material lithium nickelate for nonaqueous secondary battery, and nonaqueous secondary battery |
JPH11144710A (en) * | 1997-11-04 | 1999-05-28 | Tdk Corp | Electrode structure for electrochemical element |
JPH11265716A (en) * | 1998-03-16 | 1999-09-28 | Denso Corp | Negative electrode active material for lithium secondary battery and its manufacture |
JPH11297332A (en) * | 1998-04-13 | 1999-10-29 | Tdk Corp | Current collector and sheet type electrochemical element using the same |
JP2000123876A (en) * | 1998-10-13 | 2000-04-28 | Hosokawa Micron Corp | Manufacture of lithium ion battery material |
JP2000106183A (en) * | 1999-10-14 | 2000-04-11 | Hitachi Ltd | Non-aqueous secondary battery and manufacture of graphite powder |
JP2001155777A (en) * | 1999-11-26 | 2001-06-08 | Kyocera Corp | Lithium battery |
JP2001185126A (en) * | 1999-12-22 | 2001-07-06 | Kyocera Corp | Lithium secondary battery and manufacturing method thereof |
JP2002008657A (en) * | 2000-06-23 | 2002-01-11 | Asahi Glass Co Ltd | Negative electrode material for secondary power source, manufacturing method of secondary power source and negative electrode material |
JP2002042787A (en) * | 2000-07-28 | 2002-02-08 | Matsushita Electric Ind Co Ltd | Lithium secondary battery and manufacturing method for it |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005243447A (en) * | 2004-02-26 | 2005-09-08 | Jfe Chemical Corp | Negative electrode material for lithium ion secondary battery, negative electrode and lithium ion secondary battery |
JP4542352B2 (en) * | 2004-02-26 | 2010-09-15 | Jfeケミカル株式会社 | Negative electrode for lithium ion secondary battery and lithium ion secondary battery |
JP2005276609A (en) * | 2004-03-24 | 2005-10-06 | Tdk Corp | Composite particle for electrode, electrode, electrochemical element, and manufacturing methods for them |
JP4552475B2 (en) * | 2004-03-24 | 2010-09-29 | Tdk株式会社 | Composite particle for electrode, electrode and electrochemical element, and method for producing composite particle for electrode, method for producing electrode, and method for producing electrochemical element |
JP2006216395A (en) * | 2005-02-04 | 2006-08-17 | Tdk Corp | Lithium ion battery pack |
JP2009206079A (en) * | 2008-01-30 | 2009-09-10 | Panasonic Corp | Nonaqueous secondary battery and method for producing the same |
JP2010123580A (en) * | 2010-02-03 | 2010-06-03 | Sharp Corp | Lithium secondary battery |
US10431808B2 (en) | 2010-12-22 | 2019-10-01 | Enevate Corporation | Electrodes, electrochemical cells, and methods of forming electrodes and electrochemical cells |
US10985361B2 (en) | 2010-12-22 | 2021-04-20 | Enevate Corporation | Electrodes configured to reduce occurrences of short circuits and/or lithium plating in batteries |
US11837710B2 (en) | 2010-12-22 | 2023-12-05 | Enevate Corporation | Methods of reducing occurrences of short circuits and/or lithium plating in batteries |
US11784298B2 (en) | 2010-12-22 | 2023-10-10 | Enevate Corporation | Methods of reducing occurrences of short circuits and/or lithium plating in batteries |
US10388943B2 (en) | 2010-12-22 | 2019-08-20 | Enevate Corporation | Methods of reducing occurrences of short circuits and/or lithium plating in batteries |
US11177467B2 (en) | 2010-12-22 | 2021-11-16 | Enevate Corporation | Electrodes, electrochemical cells, and methods of forming electrodes and electrochemical cells |
US10516155B2 (en) | 2010-12-22 | 2019-12-24 | Enevate Corporation | Electrodes, electrochemical cells, and methods of forming electrodes and electrochemical cells |
JP2016514356A (en) * | 2013-03-12 | 2016-05-19 | エネヴェート・コーポレーション | Electrode, electrochemical cell, and method for forming electrode and electrochemical cell |
WO2016152860A1 (en) * | 2015-03-24 | 2016-09-29 | 日本電気株式会社 | Lithium ion secondary battery and method for manufacturing same |
JPWO2016152860A1 (en) * | 2015-03-24 | 2018-01-18 | 日本電気株式会社 | Lithium ion secondary battery and manufacturing method thereof |
JPWO2017090242A1 (en) * | 2015-11-27 | 2018-09-13 | 日本ゼオン株式会社 | Non-aqueous secondary battery adhesive layer composition, non-aqueous secondary battery adhesive layer, and non-aqueous secondary battery |
US10686214B2 (en) | 2017-12-07 | 2020-06-16 | Enevate Corporation | Sandwich electrodes and methods of making the same |
US11133498B2 (en) | 2017-12-07 | 2021-09-28 | Enevate Corporation | Binding agents for electrochemically active materials and methods of forming the same |
US11901500B2 (en) | 2017-12-07 | 2024-02-13 | Enevate Corporation | Sandwich electrodes |
US11916228B2 (en) | 2017-12-07 | 2024-02-27 | Enevate Corporation | Binding agents for electrochemically active materials and methods of forming the same |
JP2022013199A (en) * | 2020-07-03 | 2022-01-18 | トヨタ自動車株式会社 | Electrode structure body |
JP7226401B2 (en) | 2020-07-03 | 2023-02-21 | トヨタ自動車株式会社 | electrode structure |
Also Published As
Publication number | Publication date |
---|---|
JP4561041B2 (en) | 2010-10-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7195844B2 (en) | Lithium secondary battery | |
US9166251B2 (en) | Battery separator and nonaqueous electrolyte battery | |
US8932762B2 (en) | Active material and positive electrode and lithium-ion second battery using same | |
US20050285080A1 (en) | Electrode composite particles, electrode and electrochemical element, method of manufacturing the electrode composite particles, electrode manufacturing method, electrochemical element manufacturing method | |
CN110574191B (en) | Method for forming lithium metal and inorganic material composite thin film, and method for prelithiating negative electrode of lithium secondary battery using the same | |
JP5734813B2 (en) | Battery electrode, non-aqueous electrolyte battery, and battery pack | |
JP2007335331A (en) | Positive electrode active material and its manufacturing method, positive electrode, its manufacturing method, and secondary battery | |
WO2015040747A1 (en) | Non-aqueous electrolyte battery electrode, non-aqueous electrolyte battery, and battery pack | |
WO2014010476A1 (en) | Electrode for lithium secondary cell, method for manufacturing same, lithium secondary cell, and method for manufacturing same | |
US20080206639A1 (en) | Active material particle for electrode, electrode, electrochemical device, and production method of electrode | |
JP4561041B2 (en) | Lithium secondary battery | |
CA3040031C (en) | Battery module for starting a power equipment | |
JP6656370B2 (en) | Lithium ion secondary battery and battery pack | |
JP6629110B2 (en) | Non-aqueous electrolyte battery, battery pack and vehicle | |
JP2011086448A (en) | Lithium ion secondary battery | |
JP2003297354A (en) | Lithium secondary battery | |
WO2020059806A1 (en) | Secondary battery | |
JP2003173821A (en) | Nonaqueous electrolyte cell | |
JP2014022245A (en) | Lithium ion secondary battery and manufacturing method thereof | |
JP2019169346A (en) | Lithium ion secondary battery | |
JP2022077319A (en) | Anode active material | |
WO2015037522A1 (en) | Nonaqueous secondary battery | |
JP7233389B2 (en) | Method for producing porous silicon particles, method for producing electrode for power storage device, method for producing all-solid lithium ion secondary battery, porous silicon particles, electrode for power storage device, and all-solid lithium ion secondary battery | |
JP5217066B2 (en) | Lithium secondary battery | |
WO2024127668A1 (en) | Non-aqueous electrolyte battery and battery pack |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20040601 |
|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20051125 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080910 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080924 |
|
A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20081125 |
|
A602 | Written permission of extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A602 Effective date: 20081128 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20081224 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100330 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100531 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100706 |
|
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100719 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130806 Year of fee payment: 3 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
LAPS | Cancellation because of no payment of annual fees |