JP2004071232A - Nonaqueous primary battery and manufacturing method for active material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge a discharge capacity and lower the operating voltage while miniaturizing and lightening the weight of a primary battery. <P>SOLUTION: This primary battery is provided with aqueous electrolyte disposed with a cathode active material 4 using oxy nickel hydroxide as a major component and an anode active material 5 composed of light metal between a positive electrode terminal 2 and a negative electrode terminal 3 by divided by a separator 6. The cathode active material is formed of β type oxy nickel hydroxide formed by solving a prescribed amount of an element selected from lanthanoids. This constitution can extremely enlarge its discharge capacity, miniaturize and lighten the weight of the primary battery and lower the operating voltage. <P>COPYRIGHT: (C)2004,JPO

Description

【００３５】
正極合剤を充填する際、略球状の粒子形状８のβ型オキシ水酸化ニッケルは、岩石状（非球状）の粒子形状９のβ型オキシ水酸化ニッケルに比べ、Ｔａｐ密度、Ｂｕｌｋ密度が高く、一定容積に対してより多くの量を充填することが可能であるため、活物質の高容量化ができる。
【００３６】
このようにして作製した比較例１及び比較例２のコイン型電池では、作製直後の開路電圧は略３．５Ｖ程度であるが、放電を行うことにより急激に電圧が低下し、略１．０〜１．２Ｖ付近でほぼ平坦な電位を示すという特徴をもつ。
【００３７】
従って、このコイン型電池の放電特性は、予備放電を行って放電初期の部分を除外した状態で、放電試験を行うこととする。この予備放電は、１ｍＡの定電流で、電池電圧が１．３Ｖになるまで放電し、その後、丸１日経過させるものである。
【００３８】
予備放電後、１ｍＡと５ｍＡの定電流で、電池電圧が０．５Ｖになるまで放電させる放電試験を行い、その際の比較例１及び比較例２のコイン型電池の放電容量を表２に示す。
【００３９】
【表２】

【００４０】
この表２から明らかなように、１ｍＡ放電、５ｍＡ放電いずれの場合にも、正極活物質には略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した比較例２の方が、岩石状（非球状）の粒子形状のβ型オキシ水酸化ニッケル９を使用した比較例１よりも放電容量が大きいことが理解できる。
【００４１】
これは、一定容積に対し、一定圧力で充填可能である正極合剤の量が、略球状の粒子形状のβ型オキシ水酸化ニッケル８の方が、岩石状（非球状）の粒子形状のβ型オキシ水酸化ニッケル９よりも多いためであると考えられる。このことより、非水系一次電池としてβ型オキシ水酸化ニッケルを用いた場合、略球状の粒子形状のβ型オキシ水酸化ニッケル８を用いた方が良いことが分かる。
【００４２】
そこで、本発明に係る具体的な実施例、即ち略球状の粒子形状のβ型オキシ水酸化ニッケル８を用い、且つサマリウム、イッテルビウム、ガドリニウム、セリウム、エルビウムまたはホルミウムの固容量を変化させたものについて、また、幾つかの比較例を挙げて説明する。
【００４３】
（実施例１乃至７）
これらの実施例１乃至７においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．１〜２．５重量％の範囲においてサマリウム（Ｓｍ）の量を変えて固溶させたものである。このサマリウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４の成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の態様で説明したものと同様にして、コイン型電池１を作製した。
【００４４】
サマリウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化サマリウムとを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、サマリウムを固溶した水酸化ニッケルを作製する。
【００４５】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、上記で作製した水酸化ニッケルを投入し、化学酸化することによって、サマリウム固溶の略球状を呈するβ型オキシ水酸化ニッケルを作製する。
【００４６】
このように、β型オキシ水酸化ニッケルにサマリウムを固溶できれば良いのであるから、サマリウムを固溶したβ型オキシ水酸化ニッケルの作製方法は、前述した方法に限られるものではなく、サマリウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いることもできる。
【００４７】
サマリウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【００４８】
（比較例３）
比較例３においては、前記実施例１乃至７におけるサマリウムの固溶量０．１重量％以下、即ち０．０５重量％に変化させたものであって、その他については、実施例１乃至７と同様にして作製した。
【００４９】
サマリウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した比較例２と、所定量のサマリウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例１乃至７及び比較例３について、１ｍＡ及び５ｍＡ放電を行った時の放電容量を表３に示し、このときのサマリウム（Ｓｍ）固溶量に対する放電容量の変化については図４に示す。
【００５０】
【表３】

【００５１】
表３及び図４から明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のサマリウムを固溶させると、放電容量を向上させることができ、特に、サマリウムの固溶量を０．１〜２．５重量％の範囲とした実施例１乃至７と、０．０５重量％とした比較例３とでは、実施例１乃至７の方がその効果が大きいことが分かる。
【００５２】
このように、サマリウムの固溶量が０．１重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．１重量％以上である場合に放電容量を向上させる効果を十分に得ることができることが理解できる。
【００５３】
これについて、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにサマリウムを固溶させた場合、ニッケルのサイトがサマリウムで置換され、その際、サマリウムはニッケルに比べてイオン半径が大きいので、サマリウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推定される。
【００５４】
また、代表的な実施例３，７及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡの定電流時のサマリウムの固溶量に対する放電容量の変化を図５に示し、５ｍＡの定電流時のサマリウムの固溶量に対する放電容量の変化を図６に示す。なお、これら図において、比較例２の放電容量の変化特性を曲線１１ａ，２１ａで示し、実施例３の放電容量の変化特性を曲線１２，２２で示し、実施例７の放電容量の変化特性を曲線１３，２３でそれぞれ示してある。
【００５５】
図５及び図６より明らかなように、１ｍＡ放電，５ｍＡ放電のいずれの場合にも、サマリウムを固溶していない比較例２の放電特性１１ａ，２１ａよりも、サマリウムを固溶した実施例３の放電特性１２，２２、実施例７の放電特性１３，２３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、サマリウムの固溶量を増加しさえすれば、放電容量を向上できることが理解される。
【００５６】
しかしながら、サマリウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、サマリウムはニッケルに比べてイオン半径が大きいため、現在の技術では、２．５重量％が固溶の限界であり、２．５重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【００５７】
また、実施例７を例とした場合に、１ｍＡ定電流放電時の放電容量は、表３より７２．０ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略９２３ｍＡｈ／ｇ（＝７２．０／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【００５８】
従って、正極活物質に固溶されるサマリウムが、β型オキシ水酸化ニッケルの０．１〜２．５重量％の範囲であるときに、サマリウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではサマリウムの固溶量を０．１〜２．５重量％とすることが好ましい。
【００５９】
（実施例８乃至１４）
実施例８乃至１４においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．２〜３．０重量％の範囲において金属化合物であるイッテルビウム（Ｙｂ）の量を変えて固溶させたものである。このイッテルビウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の形態で説明したものと同様にして、コイン型電池１を作製した。
【００６０】
イッテルビウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化イッテルビウムを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、イッテルビウムを固溶した水酸化ニッケルを作製する。
【００６１】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、前述のイッテルビウムを固溶した水酸化ニッケルを投入し、化学酸化することによって、イッテルビウム固溶の略球状β型オキシ水酸化ニッケルを作製する。この場合も、要するに、イッテルビウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いても良い。
【００６２】
また、イッテルビウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【００６３】
（比較例４乃至５）
比較例４乃至５は、前記実施例８乃至１４におけるイッテルビウムの固溶量０．２重量％以下の０．０５〜０．１重量％の範囲にしたものであって、その他については、実施例８乃至１４と同様にして作製した。
【００６４】
イッテルビウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した、例えば、前記した比較例２と、所要量のイッテルビウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例８乃至１４及び比較例４乃至５について、１ｍＡ又は５ｍＡ放電を行った時の放電容量を表４に示し、このときのイッテルビウム（Ｙｂ）固溶量に対する放電容量の変化を図７に示す。
【００６５】
【表４】

【００６６】
表４及び図７から明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のイッテルビウムを固溶させると、放電容量を向上させることができ、特に、イッテルビウムの固溶量を０．２〜３．０重量％の範囲とした実施例８乃至１４と、０．０５〜０．１重量％の範囲とした比較例４乃至５とでは、実施例８乃至１４の方がその効果が大きいことが分かる。
【００６７】
このように、イッテルビウムの固溶量が０．２重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．２重量％以上である場合に放電容量を向上させる効果を十分に得ることができることが理解できる。
【００６８】
これについても、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにイッテルビウムを固溶させた場合、ニッケルのサイトがイッテルビウムで置換され、その際、イッテルビウムはニッケルに比べてイオン半径が大きいので、イッテルビウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推定される。
【００６９】
また、代表的な実施例８，１２及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡの定電流時のイッテルビウムの固溶量に対する放電容量の変化を図８に示し、５ｍＡの定電流時のイッテルビウムの固溶量に対する放電容量の変化を図９に示す。なお、これら図において、比較例２の放電容量の変化特性を曲線１１ｂ，２１ｂで示し、実施例８の放電容量の変化特性を曲線３２，４２で示し、実施例１２の放電容量の変化特性を曲線３３，４３でそれぞれ示してある。
【００７０】
図８及び図９より明らかなように、１ｍＡ放電，５ｍＡ放電のいずれの場合にも、イッテルビウムを固溶していない比較例２の放電特性１１ｂ，２１ｂよりも、イッテルビウムを固溶した実施例８の放電特性３２，４２、実施例１２の放電特性３３，４３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、イッテルビウムの固溶量を増加しさえすれば、放電容量を向上できることが理解される。
【００７１】
しかしながら、イッテルビウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、イッテルビウムはニッケルに比べてイオン半径が大きいため、現在の技術では、３．０重量％が固溶の限界であり、３．０重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【００７２】
また、実施例１４を例とした場合に、１ｍＡ定電流放電時の放電容量は、表４より６６．０ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略８４６ｍＡｈ／ｇ（＝６６．０／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【００７３】
従って、正極活物質に固溶されるイッテルビウムが、β型オキシ水酸化ニッケルの０．２〜３．０重量％の範囲であるときに、イッテルビウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではイッテルビウムの固溶量を０．２〜３．０重量％とすることが好ましい。
【００７４】
（実施例１５乃至２２）
実施例１５乃至２２においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．１〜３．０重量％の範囲において金属化合物であるガドリニウム（Ｇｄ）の量を変えて固溶させたものである。このガドリニウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の形態で説明したものと同様にして、コイン型電池１を作製した。
【００７５】
ガドリニウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化ガドリニウムとを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、ガドリニウムを固溶した水酸化ニッケルを作製する。
【００７６】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、前述のガドリニウムを固溶した水酸化ニッケルを投入し、化学酸化することによって、ガドリニウム固溶の略球状β型オキシ水酸化ニッケルを作製する。この場合も、要するに、ガドリニウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いても良い。
【００７７】
また、ガドリニウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【００７８】
（比較例６）
比較例６は、前記実施例１５乃至２２におけるガドリニウムの固溶量０．１重量％以下の０．０５重量％にしたものであって、その他については、実施例１５乃至２２と同様にして作製した。
【００７９】
ガドリニウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した、例えば、前記した比較例２と、所要量のガドリニウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例１５乃至２２及び比較例６について、１ｍＡ放電を行ったときの放電容量を表５に示すと共に、このときのガドリニウム（Ｇｄ）固溶量に対する放電容量の変化を図１０に示す。
【００８０】
【表５】

【００８１】
表５及び図１０より明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のガドリニウムを固溶させると、放電容量を向上させることができ、特に、ガドリニウムの固溶量を０．１〜３．０重量％の範囲とした実施例１５乃至２２と、０．０５重量％とした比較例６とでは、実施例１５乃至２２の方がその効果が大きいことが分かる。
【００８２】
このように、ガドリニウムの固溶量が０．１重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．１重量％以上である場合に放電容量を向上させる効果が十分に得られることが理解できる。
【００８３】
これについても、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにガドリニウムを固溶させた場合、ニッケルのサイトがガドリニウムで置換され、その際、ガドリニウムはニッケルに比べてイオン半径が大きいので、ガドリニウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推察される。
【００８４】
また、代表的な実施例１５，２０及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡの定電流時のガドリニウムの固溶量に対する放電容量の変化を図１１に示す。なお、この図において、比較例２の放電容量の変化特性を曲線１１ｃで示し、実施例１５の放電容量の変化特性を曲線５２で示し、実施例２０の放電容量の変化特性を曲線５３でそれぞれ示してある。
【００８５】
図１１より明らかなように、１ｍＡ放電を行った場合、ガドリニウムを固溶していない比較例２の放電特性１１ｃよりも、ガドリニウムを固溶した実施例１５の放電特性５２、実施例２０の放電特性５３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、ガドリニウムの固溶量を増加することによって、放電容量が向上していることが分かる。
【００８６】
しかしながら、ガドリニウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、ガドリニウムはニッケルに比べてイオン半径が大きいため、現在の技術では、３．０重量％が固溶の限界であり、３．０重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【００８７】
また、実施例２２を例とした場合に、１ｍＡ定電流放電時の放電容量は、表５より８８．０ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略１１２８ｍＡｈ／ｇ（＝８８．０／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【００８８】
従って、正極活物質に固溶されるガドリニウムが、β型オキシ水酸化ニッケルの０．１〜３．０重量％の範囲であるときに、ガドリニウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではガドリニウムの固溶量を０．１〜３．０重量％とすることが好ましい。
【００８９】
（実施例２３乃至２８）
実施例２３乃至２８においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．２〜２．５重量％の範囲において金属化合物であるセリウム（Ｃｅ）の量を変えて固溶させたものである。このセリウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の形態で説明したものと同様にして、コイン型電池１を作製した。
【００９０】
セリウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化セリウムとを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、セリウムを固溶した水酸化ニッケルを作製する。
【００９１】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、前述のセリウムを固溶した水酸化ニッケルを投入し、化学酸化することによって、セリウム固溶の略球状β型オキシ水酸化ニッケルを作製する。この場合も、要するに、セリウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いても良い。
【００９２】
また、セリウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【００９３】
（比較例７）
比較例７は、前記実施例２３乃至２８におけるセリウムの固溶量０．２重量％以下の０．１重量％にしたものであって、その他については、実施例２３乃至２８と同様にして作製した。
【００９４】
セリウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した、例えば、前記した比較例２と、所要量のセリウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例２３乃至２８及び比較例７について、１ｍＡ放電を行ったときの放電容量を表６に示すと共に、このときのセリウム（Ｃｅ）固溶量に対する放電容量の変化を図１２に示す。
【００９５】
【表６】

【００９６】
表６及び図１２より明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のセリウムを固溶させると、放電容量を向上させることができ、特に、セリウムの固溶量を０．２〜２．５重量％の範囲とした実施例２３乃至２８と、０．１重量％とした比較例７とでは、実施例２３乃至２８の方がその効果が大きいことが分かる。
【００９７】
このように、セリウムの固溶量が０．２重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．２重量％以上である場合に放電容量を向上させる効果が十分に得られることが理解できる。
【００９８】
これについても、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにセリウムを固溶させた場合、ニッケルのサイトがセリウムで置換され、その際、セリウムはニッケルに比べてイオン半径が大きいので、セリウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推察される。
【００９９】
また、代表的な実施例２３，２７及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡの定電流時のガドリニウムの固溶量に対する放電容量の変化を図１３に示す。なお、この図において、比較例２の放電容量の変化特性を曲線１１ｄで示し、実施例２３の放電容量の変化特性を曲線６２で示し、実施例２７の放電容量の変化特性を曲線６３でそれぞれ示してある。
【０１００】
図１３より明らかなように、１ｍＡ放電を行った場合、セリウムを固溶していない比較例２の放電特性１１ｄよりも、セリウムを固溶した実施例２３の放電特性６２、実施例２７の放電特性６３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、セリウムの固溶量を増加することによって、放電容量が向上していることが分かる。
【０１０１】
しかしながら、セリウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、セリウムはニッケルに比べてイオン半径が大きいため、現在の技術では、２．５重量％が固溶の限界であり、２．５重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【０１０２】
また、実施例２８を例とした場合に、１ｍＡ定電流放電時の放電容量は、表６より６５．９ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略８４５ｍＡｈ／ｇ（＝６５．９／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【０１０３】
従って、正極活物質に固溶されるセリウムが、β型オキシ水酸化ニッケルの０．２〜２．５重量％の範囲であるときに、セリウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではセリウムの固溶量を０．２〜２．５重量％とすることが好ましい。
【０１０４】
（実施例２９乃至３６）
実施例２９乃至３６においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．１〜３．０重量％の範囲において金属化合物であるエルビウム（Ｅｒ）の量を変えて固溶させたものである。このエルビウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の形態で説明したものと同様にして、コイン型電池１を作製した。
【０１０５】
エルビウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化エルビウムとを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、エルビウムを固溶した水酸化ニッケルを作製する。
【０１０６】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、前述のエルビウムを固溶した水酸化ニッケルを投入し、化学酸化することによって、エルビウム固溶の略球状β型オキシ水酸化ニッケルを作製する。この場合も、要するに、エルビウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いても良い。
【０１０７】
また、エルビウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【０１０８】
（比較例８）
比較例８は、前記実施例２９乃至３６におけるエルビウムの固溶量０．１重量％以下の０．０５重量％にしたものであって、その他については、実施例２９乃至３６と同様にして作製した。
【０１０９】
エルビウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した、例えば、前記した比較例２と、所要量のエルビウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例２９乃至３６及び比較例８について、１ｍＡ放電を行ったときの放電容量を表７に示すと共に、このときのエルビウム（Ｅｒ）固溶量に対する放電容量の変化を図１４に示す。
【０１１０】
【表７】

【０１１１】
表７及び図１４より明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のエルビウムを固溶させると、放電容量を向上させることができ、特に、エルビウムの固溶量を０．１〜３．０重量％の範囲とした実施例２９乃至３６と、０．０５重量％とした比較例８とでは、実施例２９乃至３６の方がその効果が大きいことが分かる。
【０１１２】
このように、エルビウムの固溶量が０．１重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．１重量％以上である場合に放電容量を向上させる効果が十分に得られることが理解できる。
【０１１３】
これについても、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにエルビウムを固溶させた場合、ニッケルのサイトがエルビウムで置換され、その際、エルビウムはニッケルに比べてイオン半径が大きいので、エルビウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推察される。
【０１１４】
また、代表的な実施例２９，３４及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡ定電流時のエルビウムの固溶量に対する放電容量の変化を図１５に示す。なお、この図において、比較例２の放電容量の変化特性を曲線１１ｅで示し、実施例２９の放電容量の変化特性を曲線７２で示し、実施例３４の放電容量の変化特性を曲線７３でそれぞれ示してある。
【０１１５】
図１５より明らかなように、１ｍＡ放電を行った場合、エルビウムを固溶していない比較例２の放電特性１１ｅよりも、エルビウムを固溶した実施例２９の放電特性７２、実施例３４の放電特性７３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、エルビウムの固溶量を増加することによって、放電容量が向上していることが分かる。
【０１１６】
しかしながら、エルビウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、エルビウムはニッケルに比べてイオン半径が大きいため、現在の技術では、３．０重量％が固溶の限界であり、３．０重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【０１１７】
また、実施例３６を例とした場合に、１ｍＡ定電流放電時の放電容量は、表７より８５．４ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略１０９５ｍＡｈ／ｇ（＝８５．４／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【０１１８】
従って、正極活物質に固溶されるエルビウムが、β型オキシ水酸化ニッケルの０．１〜３．０重量％の範囲であるときに、エルビウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではエルビウムの固溶量を０．１〜３．０重量％とすることが好ましい。
【０１１９】
（実施例３７乃至４４）
実施例３７乃至４４においては、それぞれ略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用し、これに０．１〜３．０重量％の範囲において金属化合物であるホルミウム（Ｈｏ）の量を変えて固溶させたものである。このホルミウムの量を変えて固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用する以外は、正極合剤の作製、正極ペレット４成型、負極活物質５の作製、セパレータ６の介在等については、前記実施の形態で説明したものと同様にして、コイン型電池１を作製した。
【０１２０】
ホルミウムを固溶したβ型オキシ水酸化ニッケルの作製方法としては、例えば、硫酸ニッケルと酸化ホルミウムとを所定の比率で混合した水溶液と、硫酸アンモニウム等のアンモニウム供給物と、水酸化ナトリウム等のアルカリ水溶液とを攪拌及び混合し、ホルミウムを固溶した水酸化ニッケルを作製する。
【０１２１】
水酸化ナトリウム等のアルカリ水溶液と、次亜鉛素酸ナトリウム等の酸化剤の混合溶液中に、前述のホルミウムを固溶した水酸化ニッケルを投入し、化学酸化することによって、ホルミウム固溶の略球状β型オキシ水酸化ニッケルを作製する。この場合も、要するに、ホルミウムを固溶したβ型オキシ水酸化ニッケルを作製できる方法であれば、他の方法を用いても良い。
【０１２２】
また、ホルミウムの固溶量については、キレート滴定により金属元素全体を定量し、その後、ＩＣＰ（高周波プラズマ発光分析）によって、ニッケル以外の微量元素の定量を行った。
【０１２３】
（比較例９）
比較例９は、前記実施例３７乃至４４におけるガドリニウムの固溶量０．１重量％以下の０．０５重量％にしたものであって、その他については、実施例３７乃至４４と同様にして作製した。
【０１２４】
ホルミウムを固溶していない略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した、例えば、前記した比較例２と、所要量のホルミウムを固溶した略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用した実施例３７乃至４４及び比較例９について、１ｍＡ放電を行ったときの放電容量を表８に示すと共に、このときのホルミウム（Ｈｏ）固溶量に対する放電容量の変化を図１６に示す。
【０１２５】
【表８】

【０１２６】
表８及び図１６より明らかなように、正極活物質であるβ型オキシ水酸化ニッケルに所要量のホルミウムを固溶させると、放電容量を向上させることができ、特に、ホルミウムの固溶量を０．１〜３．０重量％の範囲とした実施例３７乃至４４と、０．０５重量％とした比較例９とでは、実施例３７乃至４４の方がその効果が大きいことが分かる。
【０１２７】
このように、ホルミウムの固溶量が０．１重量％よりも少ないと、放電容量を向上させる効果が十分でなく、０．１重量％以上である場合に放電容量を向上させる効果が十分に得られることが理解できる。
【０１２８】
これについても、詳しいメカニズムは解明していないが、オキシ水酸化ニッケルにホルミウムを固溶させた場合、ニッケルのサイトがホルミウムで置換され、その際、ホルミウムはニッケルに比べてイオン半径が大きいので、ホルミウムを固溶することで、オキシ水酸化ニッケルの結晶が歪み、このことが負極活物質であるリチウムとの反応性を向上させているものと推察される。
【０１２９】
また、代表的な実施例３７，４２及び比較例２を例とした略球状の粒子形状８のβ型オキシ水酸化ニッケルについて、１ｍＡ定電流時のホルミウムの固溶量に対する放電容量の変化を図１７に示す。なお、この図において、比較例２の放電容量の変化特性を曲線１１ｆで示し、実施例３７の放電容量の変化特性を曲線８２で示し、実施例４２の放電容量の変化特性を曲線８３でそれぞれ示してある。
【０１３０】
図１７より明らかなように、１ｍＡ放電を行った場合、ホルミウムを固溶していない比較例２の放電特性１１ｆよりも、ホルミウムを固溶した実施例３７の放電特性８２、実施例４２の放電特性８３の方がその放電容量が大きいことが分かり、その際に、１．０〜１．２Ｖ付近でほぼ平坦な電位を示すことが分かる。更に、ホルミウムの固溶量を増加することによって、放電容量が向上していることが分かる。
【０１３１】
しかしながら、ホルミウムの固溶量を多くすることで、放電容量を向上させることができるが、前述のように、ホルミウムはニッケルに比べてイオン半径が大きいため、現在の技術では、３．０重量％が固溶の限界であり、３．０重量％以上の固溶が可能になれば、放電容量を大きくするという意味で、本発明においては、その固溶が可能になった範囲まで含むものである。
【０１３２】
また、実施例４４を例とした場合に、１ｍＡ定電流放電時の放電容量は、表８より８４．３ｍＡｈであり、これを正極活物質の充填量を用いて計算すると、重量あたりの容量としては略１０８１ｍＡｈ／ｇ（＝８４．３／０．１／０．７８）という結果が得られ、従来の電池用正極材料と比べても、非常に大きな値であることが分かる。
【０１３３】
従って、正極活物質に固溶されるホルミウムが、β型オキシ水酸化ニッケルの０．１〜３．０重量％の範囲であるときに、ホルミウムを固溶していない比較例２と比較して、著しく放電容量を向上させることができ、従来の電池用正極材料と比べても、非常に大きな値とすることができるので、現段階ではホルミウムの固溶量を０．１〜３．０重量％とすることが好ましい。
【０１３４】
尚、コイン型電池１について説明したが、略球状の粒子形状のβ型オキシ水酸化ニッケル８を使用していれば足りるので、このような非水系一次電池はコイン型電池１の形状に限るものではない。
【０１３５】
更に、実施例として説明していないが、例えば、岩石状の粒子形状のβ型オキシ水酸化ニッケル９を使用した場合でも、所要量のサマリウム、イッテルビウム、ガドリニウム、セリウム、エルビウムまたはホルミウムを固溶させることによって、充填容量は変わらないが、これら金属を固溶させていない従来例に比べて、放電容量を相当量向上させることができるのであって、要するに、本発明は、所要量のサマリウム、イッテルビウム、ガドリニウム、セリウム、エルビウムまたはホルミウム等のランタノイド属より選ばれた元素をβ型オキシ水酸化ニッケルに固溶させることに基本的な技術改良が存するのである。
【０１３６】
【発明の効果】
以上説明したように、本発明に係る非水系一次電池は、正極端子と負極端子との間に、オキシ水酸化ニッケルを主成分とする正極活物質と軽金属からなる負極活物質とをセパレータで区分して配設すると共に、非水電解質を備えた一次電池であって、前記正極活物質は、ランタノイド属の元素、例えば、サマリウム、イッテルビウム、ガドリニウム、セリウム、エルビウムまたはホルミウムのいずれかを所要量固溶したβ型オキシ水酸化ニッケルで形成したことにより、その放電容量を著しく大きくすることができ、それによって一次電池の小型軽量化が図れるばかりでなく、作動電圧を低くすることができるという優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施の形態に係るコイン型電池の略示的断面図である。
【図２】同実施の形態に使用される略球状の粒子形状のオキシ水酸化ニッケルの電子顕微鏡写真である。
【図３】比較例１の電池に使用される岩石状（非球状）のオキシ水酸化ニッケルの電子顕微鏡写真である。
【図４】本発明の実施の形態に係るサマリウム固溶の正極活物質を使用したコイン型電池の１ｍＡと５ｍＡの定電流時におけるサマリウムの固溶量に対する放電容量の変化を示す表である。
【図５】本発明の具体的実施例３及び実施例７と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【図６】本発明の具体的実施例３及び実施例７と、比較例２のコイン型電池の５ｍＡの定電流時における放電容量の変化を示す表である。
【図７】本発明の実施の形態に係るイッテルビウム固溶の正極活物質を使用したコイン型電池の１ｍＡと５ｍＡの定電流時におけるイッテルビウムの固溶量に対する放電容量の変化を示す表である。
【図８】本発明の具体的実施例８及び実施例１２と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【図９】本発明の具体的実施例８及び実施例１２と、比較例２のコイン型電池の５ｍＡの定電流時における放電容量の変化を示す表である。
【図１０】本発明の実施の形態に係るガドリニウム固溶の正極活物質を使用したコイン型電池の１ｍＡの定電流時におけるガドリニウムの固溶量に対する放電容量の変化を示す表である。
【図１１】本発明の具体的実施例１５及び実施例２０と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【図１２】本発明の実施の形態に係るセリウム固溶の正極活物質を使用したコイン型電池の１ｍＡの定電流時におけるセリウムの固溶量に対する放電容量の変化を示す表である。
【図１３】本発明の具体的実施例２３及び実施例２７と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【図１４】本発明の実施の形態に係るエルビウム固溶の正極活物質を使用したコイン型電池の１ｍＡの定電流時におけるエルビウムの固溶量に対する放電容量の変化を示す表である。
【図１５】本発明の具体的実施例２９及び実施例３４と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【図１６】本発明の実施の形態に係るホルミウム固溶の正極活物質を使用したコイン型電池の１ｍＡの定電流時におけるホルミウムの固溶量に対する放電容量の変化を示す表である。
【図１７】本発明の具体的実施例３７及び実施例４２と、比較例２のコイン型電池の１ｍＡの定電流時における放電容量の変化を示す表である。
【符号の説明】
１　コイン型電池（非水系一次電池）；　２　正極缶（正極端子）
３　負極カップ（負極端子）；　４　正極ペレット（正極活物質）
５　負極活物質；　６　セパレータ；　７　封口ガスケット
８　略球状の粒子形状のβ型オキシ水酸化ニッケル；
９　岩石状（非球状）の粒子形状のβ型オキシ水酸化ニッケル
１１ａ乃至１１ｆ、２１ａ、２１ｂ　比較例２の放電特性
１２，２２　実施例３の放電特性；　１３，２３　実施例７の放電特性
３２，４２　実施例８の放電特性；　３３，４３　実施例１２の放電特性
５２　実施例１５の放電特性；　５３　実施例２０の放電特性
６２　実施例２３の放電特性；　６３　実施例２７の放電特性
７２　実施例２９の放電特性；　７３　実施例３４の放電特性
８２　実施例３７の放電特性；　８３　実施例４２の放電特性[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is used, for example, as a power source for small portable electronic devices and the like, and is used as a non-aqueous primary battery which is compatible with an alkaline manganese battery or an alkaline secondary battery, and an active material used as a positive electrode active material of the battery. The present invention relates to a method for producing a substance.
[0002]
[Prior art]
2. Description of the Related Art In recent years, small portable electronic devices such as portable game machines and digital cameras of a portable type have become very popular. It is thought that it will become more and more popular in the future, and it is expected that demand for primary batteries and secondary batteries, which are power sources, will also increase rapidly. Have been.
[0003]
Portable electronic devices such as portable game machines and digital cameras generally have a high operating voltage and require a large current, and therefore the batteries used as power sources must have excellent discharge characteristics under heavy loads. .
[0004]
In addition, portable electronic devices and the like tend to be smaller, lighter, and more sophisticated, and batteries that serve as power sources are expected to be smaller, lighter, and more sustainable. This means that the capacity per unit weight (mAh / g) and the capacity per unit volume (mAh / cm) of the positive electrode active material and the negative electrode active material which are the constituent materials of the battery. ³ It can be said that the larger is the better.
[0005]
To satisfy such demands, nickel-zinc batteries have been proposed in the past. These batteries use nickel oxyhydroxide as the positive electrode active material and zinc as the negative electrode active material, and operate more frequently than general alkaline manganese batteries. It is a battery with high voltage and excellent heavy load characteristics.
[0006]
In addition, the operating voltage of portable electronic devices tends to decrease year by year in order to reduce power consumption and heat generation. For example, the operating voltage of the MPU of the personal computer is generally about 1.5 V, but recently, some operate at about 1.0 V, and it is expected that the operation will be further reduced in the future. Therefore, it is also desired that the operating voltage of the power supply battery is low.
[0007]
[Problems to be solved by the invention]
However, among the existing primary batteries, it is assumed that the operating voltage is low, and MnO ₂ / Zn system, Ag ₂ O / Zn system, FeS using organic solvent for electrolyte ₂ All of these primary batteries have problems such as a small capacity per unit weight (mAh / g) with respect to the positive electrode active material, or a remarkable volume expansion after discharge, and the like. This is an obstacle to capacity increase. In addition, these primary batteries have a problem that the battery voltage at the initial stage of discharge is 1.8 to 1.5 V, and the needs for a future low voltage can not be sufficiently satisfied.
[0008]
Therefore, in the conventional primary battery, there is a problem to be solved while increasing the discharge capacity and lowering the operating voltage while reducing the size and weight.
[0009]
[Means for Solving the Problems]
As a specific means for solving the problems of the conventional example described above, a first invention according to the present invention is to provide a negative electrode active material comprising a positive electrode active material mainly composed of nickel oxyhydroxide and a light metal between a positive electrode terminal and a negative electrode terminal. A material and a separator are disposed separately, and a primary battery including a non-aqueous electrolyte is provided, wherein the positive electrode active material is a β-type nickel oxyhydroxide in which a required amount of an element selected from the lanthanoid group is dissolved. It is intended to provide a non-aqueous primary battery characterized by being formed.
[0010]
In the first aspect, the element selected from the genus lanthanoid is any one of samarium, ytterbium, gadolinium, cerium, erbium, and holmium; the solid solution amount of the element dissolved in the positive electrode active material is: , Samarium is at least 0.1% by weight of β-type nickel oxyhydroxide, ytterbium is at least 0.2% by weight of β-type nickel oxyhydroxide, and gadolinium is β-type oxyhydroxide. 0.1% by weight or more of nickel, 0.2% by weight or more of β-type nickel oxyhydroxide for cerium, and 0.1% by weight or more of β-type nickel oxyhydroxide for erbium Holmium is 0.1% by weight or more of β-type nickel oxyhydroxide; the β-type nickel oxyhydroxide of the positive electrode active material is substantially spherical. Of the formed that the particles; light metal of the negative electrode active material, lithium, a lithium alloy, magnesium, sodium, potassium, be either calcium or aluminum; is intended to include as an additional requirement.
[0011]
A second invention according to the present invention is a method for producing an active material used as a positive electrode active material of a battery, comprising the steps of: mixing sulfuric acid or nickel nitrate with a metal compound in an aqueous solution; And a step of stirring and mixing an aqueous alkali solution to produce nickel hydroxide in a metal solid solution, and in a mixed solution of the aqueous alkali solution and the oxidizing agent, a required amount of an element selected from the lanthanoid group was dissolved. An object of the present invention is to provide a method for producing an active material for a battery, characterized in that nickel oxyhydroxide is obtained by mixing and chemically oxidizing nickel hydroxide dissolved in a metal.
[0012]
In the second aspect, the element selected from the genus lanthanoid is any of samarium, ytterbium, gadolinium, cerium, erbium, and holmium; the solid solution amount of the element dissolved in the positive electrode active material is: , Samarium is at least 0.1% by weight of β-type nickel oxyhydroxide, ytterbium is at least 0.2% by weight of β-type nickel oxyhydroxide, and gadolinium is β-type oxyhydroxide. 0.1% by weight or more of nickel, 0.2% by weight or more of β-type nickel oxyhydroxide for cerium, and 0.1% by weight or more of β-type nickel oxyhydroxide for erbium Holmium is 0.1% by weight or more of β-type nickel oxyhydroxide; the β-type nickel oxyhydroxide of the positive electrode active material is substantially spherical. To the formation of the particles; is intended to include as an additional requirement.
[0013]
The non-aqueous primary battery according to the present invention forms β-type nickel oxyhydroxide in a substantially spherical particle shape as a positive electrode active material, and is formed of samarium, ytterbium, gadolinium, cerium, erbium or holmium of an element selected from the group consisting of lanthanoids. By dissolving one of them, the filling capacity is increased to increase the discharge capacity, and the operating voltage can be reduced to a low voltage of about 1.0 to 1.2V.
[0014]
Further, in the method for producing an active material for a battery according to the present invention, it is possible to obtain nickel oxyhydroxide in which a predetermined metal is dissolved in a predetermined amount by a simple process.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described in detail based on specific embodiments.
FIG. 1 shows a cross-sectional view of a coin-type battery 1 which is an example of a non-aqueous primary battery according to the present invention. The coin-type battery 1 is configured by combining a positive electrode can 2 as a positive electrode terminal and a negative electrode cup 3 as a negative electrode terminal in pairs.
[0016]
A positive electrode pellet 4 and a negative electrode active material 5 made of light metal are disposed as a positive electrode active material inside a coin-type battery 1 formed by combining a positive electrode can 2 and a negative electrode cup 3. Reference numeral 4 denotes a disk-shaped positive electrode mixture comprising a β (beta) type nickel oxyhydroxide (β-NiOOH), a conductive agent, and a binder, together with a metal mesh (not shown). is there. The positive electrode pellet 4 is disposed so as to be in electrical contact with the positive electrode can 2 serving as a positive electrode terminal, so that the positive electrode can 2 functions as an external positive electrode terminal.
[0017]
The light metal serving as the negative electrode active material 5 is not particularly limited. For example, lithium metal (Li), a lithium alloy obtained by adding an alloy element such as aluminum to lithium, magnesium, sodium, potassium, calcium, aluminum, or the like is used. Can be used. Such a negative electrode active material 5 is formed into a disk shape in the same manner as the positive electrode pellet 4 and disposed so as to be in electrical contact with the negative electrode cup 3 serving as a negative electrode terminal. Function.
[0018]
A separator 6 is provided between the positive electrode pellet 4 and the negative electrode active material 5, so that the positive electrode pellet 4 and the negative electrode active material 5, which are the positive electrode active material, are not electrically contacted. .
[0019]
A sealing gasket 7 is provided on the inner peripheral portion of the coin-type battery 1, and the positive electrode can 2 and the negative electrode cup 3 are fitted and united via the sealing gasket 7 to be integrated. ing.
[0020]
The positive electrode pellet 4 used in the present invention is β-nickel oxyhydroxide (NiOOH) 8 having a substantially spherical particle shape, as is clear from the electron micrograph shown in FIG. A required amount of an element selected from the lanthanoid group is dissolved in the nickel oxide 8 in a solid solution.
[0021]
As the element selected from the lanthanoid genus, for example, samarium, ytterbium, gadolinium, cerium, erbium, holmium, or the like can be used. For the positive electrode pellet 4 which is a positive electrode active material, any one of these elements is required. Solid solution.
[0022]
In order to manufacture such a coin-type battery 1 using β-type nickel oxyhydroxide as a positive electrode active material, a positive electrode pellet 4 is provided inside a positive electrode can 2 and a separator 6 is provided thereon. Inject an amount of non-aqueous electrolyte (electrolyte). Subsequently, the negative electrode active material 5 is disposed on the separator 6, a sealing gasket 7 is disposed on the periphery of the negative electrode cup 3, and the negative electrode cup 3 is fitted to the positive electrode can 2 via the sealing gasket 7. The coin-type battery 1 which is a kind of non-aqueous primary battery is formed by pressing and sealing the two.
[0023]
As the non-aqueous electrolyte, for example, an electrolyte obtained by dissolving a lithium salt in an organic solvent as an electrolyte can be used. Here, as the organic solvent, for example, solvents such as cyclic carbonate, cyclic ester, chain carbonate, chain ester, sulfolane, cyclic ether, chain ether, nitrile, etc., specifically, propylene carbonate, ethylene Carbonate, 1,2-dimethoxyethane, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolan, sulfolane, acetonitrile, dimethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, etc. can be used, and two or more of these can be used. It is also possible to use a mixed solvent in which is mixed.
[0024]
Further, as the non-aqueous electrolyte, a solid electrolyte, a polymer electrolyte, a non-aqueous electrolyte in which an electrolyte is mixed / dissolved in a polymer compound, a gel electrolyte in which a non-aqueous electrolyte is mixed with a polymer compound, and the like can also be used.
[0025]
As the electrolyte of the lithium salt, for example, lithium perchlorate (LiClO ₄ ), Lithium hexafluorophosphate (LiPF ₆ ), Lithium tetrafluoroborate (LiBF ₄ ), Lithium trifluoromethanesulfonate (CF ₃ SO ₃ Li) etc. can be used.
[0026]
As the separator 6, for example, a polyolefin-based microporous film such as polypropylene or polyethylene can be used.
[0027]
As a method for producing β-type nickel oxyhydroxide, for example, there is a chemical oxidation method, which is obtained by oxidizing nickel hydroxide in an alkaline liquid phase containing sodium hypochlorite as an example of the chemical oxidation method. .
[0028]
In order to understand the nickel oxyhydroxide of the present invention, FIG. 3 shows a nickel oxyhydroxide 9 having a rock-like (non-spherical) particle shape by an electron micrograph. The nickel oxyhydroxide 9 having a rock-like particle shape is for performance comparison with the nickel oxyhydroxide 8 having a substantially spherical particle shape.
[0029]
First, in a coin-type battery of the same size, the difference between the filling amount and the discharge capacity of β-type nickel oxyhydroxide 8 having a substantially spherical particle shape and β-type nickel oxyhydroxide 9 having a rock-like particle shape was compared. In order to understand the above, description will be made as Comparative Examples 1 and 2. However, the β-type nickel oxyhydroxides 8 and 9 having a substantially spherical or rock-like particle shape used in Comparative Examples 1 and 2 were formed by solid solution of any of samarium, ytterbium, gadolinium, cerium, erbium and holmium. Something that has not been used is used.
[0030]
(Comparative Example 1)
In Comparative Example 1, rock-shaped (non-spherical) particle-shaped β-type nickel oxyhydroxide 9 was 78% by weight, graphite was 20% by weight as a conductive agent, and polyvinylidene fluoride (PVdF) was 2% by weight as a binder. Are mixed and dispersed in N-methyl-2-pyrrolidone (NMP) to form a positive electrode mixture slurry.
[0031]
This positive electrode mixture slurry was dried at a temperature of 120 ° C. for 2 hours to volatilize NMP, and was crushed into a powder in a mortar to obtain a positive electrode mixture. This positive electrode mixture is press-formed into a disk shape at a predetermined pressure using a metal mesh made of aluminum, which is a metal mesh, as a support to obtain a positive electrode pellet as a positive electrode active material having a diameter of 15.5 mm and a thickness of 250 μm.
[0032]
Then, a coin-type battery having an outer shape of 20 mm and a height of 1.6 mm was manufactured through the same steps as in the above embodiment.
[0033]
(Comparative Example 2)
In Comparative Example 2, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used in place of β-type nickel oxyhydroxide having a rock-like (non-spherical) particle shape 9 of Comparative Example 1 described above. In other respects, coin-type batteries of the same size were produced in the same manner as in Comparative Example 1.
[0034]
First, Table 1 shows the filling amount of the positive electrode mixture in Comparative Examples 1 and 2.
[Table 1]

[0035]
When filling the positive electrode mixture, the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 has a higher Tap density and a bulk density than the β-type nickel oxyhydroxide having a rock-like (non-spherical) particle shape 9. Since a larger amount can be filled in a certain volume, the capacity of the active material can be increased.
[0036]
In the coin-type batteries of Comparative Examples 1 and 2 manufactured as described above, the open-circuit voltage immediately after the manufacture was approximately 3.5 V, but the voltage rapidly decreased by discharging, and the voltage was approximately 1.0 V. It has the characteristic that it shows a substantially flat potential around .about.1.2 V.
[0037]
Accordingly, the discharge characteristics of this coin-type battery are determined by performing a discharge test in a state where a preliminary discharge is performed and an initial portion of the discharge is excluded. This preliminary discharge is performed at a constant current of 1 mA until the battery voltage reaches 1.3 V, and thereafter, a full day elapses.
[0038]
After the preliminary discharge, a discharge test was performed to discharge the battery at a constant current of 1 mA and 5 mA until the battery voltage reached 0.5 V. Table 2 shows the discharge capacities of the coin batteries of Comparative Examples 1 and 2 at that time. .
[0039]
[Table 2]

[0040]
As is clear from Table 2, in both cases of 1 mA discharge and 5 mA discharge, Comparative Example 2 in which β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used as the positive electrode active material was more rock-like. It can be understood that the discharge capacity is larger than that of Comparative Example 1 using β-type nickel oxyhydroxide 9 having a (non-spherical) particle shape.
[0041]
This is because the amount of the positive electrode mixture that can be filled at a constant pressure with respect to a constant volume is such that the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape has a β (non-spherical) particle shape having a rock-like (non-spherical) particle shape. It is considered that this is because the amount is larger than that of the type nickel oxyhydroxide 9. This indicates that when β-type nickel oxyhydroxide is used as the non-aqueous primary battery, it is better to use β-type nickel oxyhydroxide 8 having a substantially spherical particle shape.
[0042]
Therefore, a specific example according to the present invention, that is, a β-type nickel oxyhydroxide 8 having a substantially spherical particle shape and a solid capacity of samarium, ytterbium, gadolinium, cerium, erbium or holmium which is changed This will be described with reference to some comparative examples.
[0043]
(Examples 1 to 7)
In Examples 1 to 7, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of samarium (Sm) was changed in the range of 0.1 to 2.5% by weight. It is a solid solution. Except for using β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which the amount of samarium is changed to form a solid solution, the preparation of the positive electrode mixture, the molding of the positive electrode pellet 4, the preparation of the negative electrode active material 5, the separation of the separator 6 As for the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0044]
As a method for producing β-type nickel oxyhydroxide in which samarium is dissolved, for example, an aqueous solution in which nickel sulfate and samarium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide Are stirred and mixed to produce nickel hydroxide in which samarium is dissolved.
[0045]
The nickel hydroxide prepared above is put into a mixed solution of an aqueous alkali solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, and chemically oxidized to form a substantially spherical solid solution of samarium β. Form nickel oxyhydroxide.
[0046]
As described above, since it is sufficient that samarium can be dissolved in β-nickel oxyhydroxide, the method of producing β-nickel oxyhydroxide in which samarium is dissolved is not limited to the above-described method. Other methods can be used as long as they can produce a dissolved β-type nickel oxyhydroxide.
[0047]
Regarding the solid solution amount of samarium, the entire metal element was quantified by chelate titration, and then trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0048]
(Comparative Example 3)
In Comparative Example 3, the solid solution amount of samarium in Examples 1 to 7 was changed to 0.1% by weight or less, that is, 0.05% by weight, and the others were changed to Examples 1 to 7. It was produced in the same manner.
[0049]
Comparative Example 2 in which β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which samarium was not dissolved was used, and β-type nickel oxyhydroxide 8 in a substantially spherical particle shape in which a predetermined amount of samarium was dissolved. Table 3 shows the discharge capacities of the used Examples 1 to 7 and Comparative Example 3 when 1 mA and 5 mA discharges were performed, and FIG. 4 shows a change in the discharge capacity with respect to the samarium (Sm) solid solution amount at this time. Show.
[0050]
[Table 3]

[0051]
As is clear from Table 3 and FIG. 4, when the required amount of samarium is dissolved in β-type nickel oxyhydroxide, which is a positive electrode active material, the discharge capacity can be improved. It can be seen that in Examples 1 to 7 in the range of 0.1 to 2.5% by weight and Comparative Example 3 in the range of 0.05% by weight, Examples 1 to 7 are more effective.
[0052]
As described above, when the solid solution amount of samarium is less than 0.1% by weight, the effect of improving the discharge capacity is not sufficient, and when it is 0.1% by weight or more, the effect of improving the discharge capacity is not sufficiently achieved. It can be understood that it can be obtained.
[0053]
Although the detailed mechanism has not been elucidated, when samarium is dissolved in nickel oxyhydroxide, the nickel site is replaced by samarium. At that time, samarium has a larger ionic radius than nickel, so samarium It is presumed that the solid solution distorts the crystal of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0054]
In addition, with respect to the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 of the typical examples 3 and 7 and the comparative example 2, the change in the discharge capacity with respect to the amount of samarium dissolved at a constant current of 1 mA was measured. FIG. 5 shows the change in the discharge capacity with respect to the solid solution amount of samarium at a constant current of 5 mA, and FIG. In these figures, the change characteristics of the discharge capacity of Comparative Example 2 are shown by curves 11a and 21a, the change characteristics of the discharge capacity of Example 3 are shown by curves 12 and 22, and the change characteristics of the discharge capacity of Example 7 are shown. These are shown by curves 13 and 23, respectively.
[0055]
As is clear from FIGS. 5 and 6, in both cases of the 1 mA discharge and the 5 mA discharge, Example 3 in which samarium was solid-dissolved was better than the discharge characteristics 11a and 21a of Comparative Example 2 in which samarium was not dissolved. It can be seen that the discharge characteristics 12 and 22 of Example 7 and the discharge characteristics 13 and 23 of Example 7 have larger discharge capacities, and at this time, they show a substantially flat potential near 1.0 to 1.2 V. . Further, it is understood that the discharge capacity can be improved only by increasing the solid solution amount of samarium.
[0056]
However, the discharge capacity can be improved by increasing the solid solution amount of samarium. However, as described above, since the ionic radius of samarium is larger than that of nickel, the current technology requires 2.5% by weight. Is the limit of solid solution, and if the solid solution of 2.5% by weight or more becomes possible, the discharge capacity is increased. In the present invention, the range includes the range in which the solid solution becomes possible.
[0057]
In the case of Example 7 as an example, the discharge capacity at the time of 1 mA constant current discharge is 72.0 mAh from Table 3, and when this is calculated using the filling amount of the positive electrode active material, the capacity per weight is obtained. Is about 923 mAh / g (= 72.0 / 0.1 / 0.78), which is a very large value as compared with the conventional battery cathode material.
[0058]
Therefore, when the samarium dissolved in the positive electrode active material is in the range of 0.1 to 2.5% by weight of the β-type nickel oxyhydroxide, the samarium is compared with Comparative Example 2 in which samarium is not dissolved. Since the discharge capacity can be remarkably improved and can be set to a very large value as compared with the conventional battery cathode material, the solid solution amount of samarium is 0.1 to 2.5 wt. % Is preferable.
[0059]
(Examples 8 to 14)
In Examples 8 to 14, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of the metal compound ytterbium (Yb) in the range of 0.2 to 3.0% by weight was used. Was changed to form a solid solution. Except for using the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which a solid solution was formed by changing the amount of ytterbium, the preparation of a positive electrode mixture, the molding of a positive electrode pellet 4, the preparation of a negative electrode active material 5, the formation of a separator 6 Regarding the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0060]
As a method for producing β-type nickel oxyhydroxide in which ytterbium is dissolved, for example, an aqueous solution in which nickel sulfate and ytterbium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide are used. Is stirred and mixed to produce nickel hydroxide in which ytterbium is dissolved.
[0061]
Into a mixed solution of an alkaline aqueous solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, the above-described nickel hydroxide in which ytterbium is dissolved is poured and chemically oxidized to form a substantially spherical ytterbium solid solution. Produce β-type nickel oxyhydroxide. In this case, in short, any other method may be used as long as it can produce β-type nickel oxyhydroxide in which ytterbium is dissolved.
[0062]
As for the amount of ytterbium dissolved, the total amount of metal elements was quantified by chelate titration, and then trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0063]
(Comparative Examples 4 and 5)
In Comparative Examples 4 and 5, the solid solution amount of ytterbium in Examples 8 to 14 was set to the range of 0.05 to 0.1% by weight, which was 0.2% by weight or less. Fabricated in the same manner as in Nos. 8 to 14.
[0064]
For example, using the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape without solid solution of ytterbium, for example, the comparative example 2 described above and the β-type oxyhydroxide having a substantially spherical particle shape with a required amount of ytterbium dissolved therein. Table 4 shows the discharge capacity of each of Examples 8 to 14 and Comparative Examples 4 to 5 using nickel hydroxide 8 when a 1 mA or 5 mA discharge was performed, and the discharge capacity with respect to the amount of ytterbium (Yb) solid solution at this time. 7 is shown in FIG.
[0065]
[Table 4]

[0066]
As is clear from Table 4 and FIG. 7, when the required amount of ytterbium is dissolved in β-type nickel oxyhydroxide as the positive electrode active material, the discharge capacity can be improved. In Examples 8 to 14 in the range of 0.2 to 3.0% by weight and Comparative Examples 4 to 5 in the range of 0.05 to 0.1% by weight, Examples 8 to 14 are more preferable. It turns out that the effect is great.
[0067]
As described above, if the solid solution amount of ytterbium is less than 0.2% by weight, the effect of improving the discharge capacity is not sufficient, and if the amount is 0.2% by weight or more, the effect of improving the discharge capacity is not sufficiently obtained. It can be understood that it can be obtained.
[0068]
Again, the detailed mechanism has not been elucidated, but when ytterbium is dissolved in nickel oxyhydroxide, the site of nickel is replaced by ytterbium, and since ytterbium has a larger ionic radius than nickel, It is presumed that the solid solution of ytterbium distorts the crystals of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0069]
Further, with respect to the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 as exemplified in the representative Examples 8, 12 and Comparative Example 2, the change in discharge capacity with respect to the amount of ytterbium dissolved at a constant current of 1 mA was measured. FIG. 8 shows the change in the discharge capacity with respect to the amount of ytterbium dissolved at a constant current of 5 mA, and FIG. In these figures, the change characteristics of the discharge capacity of Comparative Example 2 are shown by curves 11b and 21b, the change characteristics of the discharge capacity of Example 8 are shown by curves 32 and 42, and the change characteristics of the discharge capacity of Example 12 are shown. This is shown by curves 33 and 43, respectively.
[0070]
As is clear from FIGS. 8 and 9, in both cases of the 1 mA discharge and the 5 mA discharge, Example 8 in which ytterbium was solid-dissolved was better than the discharge characteristics 11b and 21b of Comparative Example 2 in which ytterbium was not dissolved. It can be seen that the discharge characteristics 32 and 42 of Example 12 and the discharge characteristics 33 and 43 of Example 12 have larger discharge capacities. At this time, it can be seen that a substantially flat potential is exhibited around 1.0 to 1.2 V. . Further, it is understood that the discharge capacity can be improved only by increasing the solid solution amount of ytterbium.
[0071]
However, the discharge capacity can be improved by increasing the solid solution amount of ytterbium. However, as described above, since the ionic radius of ytterbium is larger than that of nickel, the current technology requires 3.0 wt%. Is the limit of solid solution, and if the solid solution of 3.0% by weight or more becomes possible, the present invention includes the range in which the solid solution becomes possible in the sense of increasing the discharge capacity.
[0072]
In the case of Example 14 as an example, the discharge capacity at 1 mA constant current discharge is 66.0 mAh from Table 4, and when this is calculated using the filling amount of the positive electrode active material, the capacity per weight is calculated as Is approximately 846 mAh / g (= 66.0 / 0.1 / 0.78), which is a very large value even when compared with the conventional battery cathode material.
[0073]
Therefore, when ytterbium dissolved in the positive electrode active material was in the range of 0.2 to 3.0% by weight of the β-type nickel oxyhydroxide, as compared with Comparative Example 2 in which ytterbium did not form a solid solution. Since the discharge capacity can be remarkably improved and can be set to a very large value as compared with the conventional cathode material for a battery, the solid solution amount of ytterbium is 0.2 to 3.0 wt. % Is preferable.
[0074]
(Examples 15 to 22)
In Examples 15 to 22, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of gadolinium (Gd) as a metal compound in the range of 0.1 to 3.0% by weight was used. Was changed to form a solid solution. Except for using a β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which a solid solution was formed by changing the amount of gadolinium, preparation of a positive electrode mixture, molding of a positive electrode pellet 4, preparation of a negative electrode active material 5, Regarding the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0075]
As a method for producing β-type nickel oxyhydroxide in which gadolinium is dissolved, for example, an aqueous solution in which nickel sulfate and gadolinium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide Are stirred and mixed to produce nickel hydroxide in which gadolinium is dissolved.
[0076]
The aforementioned gadolinium-dissolved nickel hydroxide is put into a mixed solution of an alkaline aqueous solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, and chemically oxidized to form a gadolinium-dissolved substantially spherical solution. Produce β-type nickel oxyhydroxide. In this case also, in short, any other method may be used as long as it can produce β-type nickel oxyhydroxide in which gadolinium is dissolved.
[0077]
Regarding the solid solution amount of gadolinium, the total amount of the metal elements was quantified by chelate titration, and thereafter, trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0078]
(Comparative Example 6)
Comparative Example 6 was the same as Examples 15 to 22 except that the solid solution amount of gadolinium was 0.05% by weight or less in Examples 15 to 22. did.
[0079]
For example, using the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which gadolinium is not dissolved, for example, the comparative example 2 described above and the β-type oxyhydroxide having a substantially spherical particle shape in which a required amount of gadolinium is dissolved. For Examples 15 to 22 and Comparative Example 6 using nickel hydroxide 8, the discharge capacity when a 1 mA discharge was performed is shown in Table 5, and the change in the discharge capacity with respect to the gadolinium (Gd) solid solution amount at this time is shown. As shown in FIG.
[0080]
[Table 5]

[0081]
As is clear from Table 5 and FIG. 10, when a required amount of gadolinium is dissolved in β-type nickel oxyhydroxide, which is a positive electrode active material, the discharge capacity can be improved. It can be seen that in Examples 15 to 22 in the range of 0.1 to 3.0% by weight and Comparative Example 6 in the range of 0.05% by weight, Examples 15 to 22 have a greater effect.
[0082]
As described above, if the gadolinium solid solution amount is less than 0.1% by weight, the effect of improving the discharge capacity is not sufficient, and if the amount is 0.1% by weight or more, the effect of improving the discharge capacity is not sufficient. It can be understood that it can be obtained.
[0083]
Again, the detailed mechanism has not been elucidated, but when gadolinium is dissolved in nickel oxyhydroxide, the nickel site is replaced by gadolinium, and gadolinium has a larger ionic radius than nickel, It is presumed that the solid solution of gadolinium distorts the crystals of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0084]
The change of the discharge capacity with respect to the amount of gadolinium dissolved at a constant current of 1 mA for the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 as exemplified in the representative Examples 15 and 20 and Comparative Example 2 was shown. As shown in FIG. In this figure, the change characteristic of the discharge capacity of Comparative Example 2 is indicated by a curve 11c, the change characteristic of the discharge capacity of Example 15 is indicated by a curve 52, and the change characteristic of the discharge capacity of Example 20 is indicated by a curve 53. Is shown.
[0085]
As is clear from FIG. 11, when the 1 mA discharge was performed, the discharge characteristics 52 of Example 15 in which gadolinium was dissolved and the discharge characteristics in Example 20 were better than the discharge characteristics 11c of Comparative Example 2 in which gadolinium was not dissolved. It can be seen that the characteristic 53 has a larger discharge capacity, and at that time, it shows a substantially flat potential around 1.0 to 1.2 V. Further, it can be seen that the discharge capacity is improved by increasing the gadolinium solid solution amount.
[0086]
However, the discharge capacity can be improved by increasing the solid solution amount of gadolinium. However, as described above, since gadolinium has a larger ionic radius than nickel, the current technology requires 3.0% by weight. Is the limit of solid solution, and if the solid solution of 3.0% by weight or more becomes possible, the present invention includes the range in which the solid solution becomes possible in the sense of increasing the discharge capacity.
[0087]
In the case of Example 22 as an example, the discharge capacity at the time of 1 mA constant current discharge is 88.0 mAh from Table 5, and when this is calculated using the filling amount of the positive electrode active material, the capacity per weight is obtained. Is about 1128 mAh / g (= 88.0 / 0.1 / 0.78), which is a very large value as compared with the conventional battery cathode material.
[0088]
Therefore, when gadolinium dissolved in the positive electrode active material is in the range of 0.1 to 3.0% by weight of the β-type nickel oxyhydroxide, the gadolinium is compared with Comparative Example 2 in which gadolinium is not dissolved. Since the discharge capacity can be remarkably improved and can be set to a very large value as compared with the conventional cathode material for a battery, the solid solution amount of gadolinium is 0.1 to 3.0 wt. % Is preferable.
[0089]
(Examples 23 to 28)
In Examples 23 to 28, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of metal compound cerium (Ce) in the range of 0.2 to 2.5% by weight was used. Was changed to form a solid solution. Except for using β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which the amount of cerium is changed to form a solid solution, the preparation of a positive electrode mixture, the formation of a positive electrode pellet 4, the preparation of a negative electrode active material 5, the formation of a separator 6 Regarding the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0090]
As a method for producing β-type nickel oxyhydroxide in which cerium is dissolved, for example, an aqueous solution in which nickel sulfate and cerium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide Are mixed and stirred to produce nickel hydroxide in which cerium is dissolved.
[0091]
The aforementioned cerium-dissolved nickel hydroxide is poured into a mixed solution of an alkaline aqueous solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, and chemically oxidized to form a substantially spherical cerium solid solution. Produce β-type nickel oxyhydroxide. In this case, in short, any other method may be used as long as it can produce β-type nickel oxyhydroxide in which cerium is dissolved.
[0092]
Regarding the solid solution amount of cerium, the entire metal element was quantified by chelate titration, and thereafter, trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0093]
(Comparative Example 7)
Comparative Example 7 was prepared in the same manner as in Examples 23 to 28 except that the solid solution amount of cerium in Examples 23 to 28 was 0.1% by weight, which was 0.2% by weight or less. did.
[0094]
For example, the comparative example 2 described above using β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which cerium was not dissolved, and β-type oxyhydroxide having a substantially spherical particle shape in which a required amount of cerium was dissolved. With respect to Examples 23 to 28 and Comparative Example 7 using nickel hydroxide 8, Table 6 shows the discharge capacity when a 1 mA discharge was performed, and the change in the discharge capacity with respect to the cerium (Ce) solid solution amount at this time. As shown in FIG.
[0095]
[Table 6]

[0096]
As is clear from Table 6 and FIG. 12, when the required amount of cerium is dissolved in the β-type nickel oxyhydroxide as the positive electrode active material, the discharge capacity can be improved. It can be seen that the effects of Examples 23 to 28 are greater in Examples 23 to 28 in the range of 0.2 to 2.5% by weight and Comparative Example 7 in the range of 0.1% by weight.
[0097]
As described above, when the amount of cerium is less than 0.2% by weight, the effect of improving the discharge capacity is not sufficient, and when the amount is 0.2% by weight or more, the effect of improving the discharge capacity is not sufficiently obtained. It can be understood that it can be obtained.
[0098]
Although the detailed mechanism has not been elucidated yet, when cerium is dissolved in nickel oxyhydroxide as a solid solution, the sites of nickel are replaced by cerium, and since cerium has a larger ionic radius than nickel, It is presumed that the solid solution of cerium distorts the crystal of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0099]
The change in discharge capacity with respect to the solid solution amount of gadolinium at a constant current of 1 mA was measured for β-type nickel oxyhydroxide having a substantially spherical particle shape 8 as exemplified in representative examples 23 and 27 and comparative example 2. As shown in FIG. In this figure, the change characteristic of the discharge capacity of Comparative Example 2 is indicated by a curve 11d, the change characteristic of the discharge capacity of Example 23 is indicated by a curve 62, and the change characteristic of the discharge capacity of Example 27 is indicated by a curve 63. Is shown.
[0100]
As is clear from FIG. 13, when the 1 mA discharge is performed, the discharge characteristics 62 of Example 23 using cerium as a solid solution and the discharge characteristics of Example 27 as compared with the discharge characteristics 11 d of Comparative Example 2 in which cerium does not form a solid solution. It can be seen that the characteristic 63 has a larger discharge capacity, and at that time, it shows a substantially flat potential around 1.0 to 1.2 V. Further, it can be seen that the discharge capacity is improved by increasing the amount of cerium solid solution.
[0101]
However, the discharge capacity can be improved by increasing the solid solution amount of cerium. However, as described above, since cerium has a larger ionic radius than nickel, the current technology requires 2.5% by weight. Is the limit of solid solution, and if the solid solution of 2.5% by weight or more becomes possible, the discharge capacity is increased. In the present invention, the range includes the range in which the solid solution becomes possible.
[0102]
In the case of Example 28, the discharge capacity at the time of 1 mA constant current discharge was 65.9 mAh from Table 6, and when this was calculated using the filling amount of the positive electrode active material, the capacity per weight was obtained. Is about 845 mAh / g (= 65.9 / 0.1 / 0.78), which is a very large value even when compared with the conventional battery cathode material.
[0103]
Therefore, when the cerium dissolved in the positive electrode active material was in the range of 0.2 to 2.5% by weight of the β-type nickel oxyhydroxide, as compared with Comparative Example 2 in which cerium was not dissolved. Since the discharge capacity can be remarkably improved, and can be set to a very large value as compared with the conventional cathode material for batteries, the solid solution amount of cerium is 0.2 to 2.5 wt. % Is preferable.
[0104]
(Examples 29 to 36)
In Examples 29 to 36, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of metal compound erbium (Er) in the range of 0.1 to 3.0% by weight was used. Was changed to form a solid solution. Except for using β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which the amount of erbium is changed to form a solid solution, preparation of a positive electrode mixture, molding of a positive electrode pellet 4, preparation of a negative electrode active material 5, Regarding the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0105]
As a method for producing β-type nickel oxyhydroxide in which erbium is dissolved, for example, an aqueous solution in which nickel sulfate and erbium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide Are stirred and mixed to produce nickel hydroxide in which erbium is dissolved.
[0106]
The aforementioned erbium-dissolved nickel hydroxide is poured into a mixed solution of an alkali aqueous solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, and chemically oxidized to form a substantially spherical erbium-dissolved solution. Produce β-type nickel oxyhydroxide. In this case also, in short, any other method may be used as long as it can produce β-type nickel oxyhydroxide in which erbium is dissolved.
[0107]
Regarding the amount of erbium dissolved, the total amount of metal elements was quantified by chelate titration, and then trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0108]
(Comparative Example 8)
Comparative Example 8 was the same as Examples 29 to 36 except that the solid solution amount of erbium in Examples 29 to 36 was 0.05% by weight, which was 0.1% by weight or less. did.
[0109]
For example, the comparative example 2 described above using β-type nickel oxyhydroxide having a substantially spherical particle shape without solid solution of erbium and the β-type oxyhydroxide having a substantially spherical particle shape having a required amount of erbium dissolved therein. With respect to Examples 29 to 36 and Comparative Example 8 using nickel hydroxide 8, the discharge capacities when 1 mA discharge was performed are shown in Table 7, and the change of the discharge capacities with respect to the erbium (Er) solid solution amount at this time is shown. As shown in FIG.
[0110]
[Table 7]

[0111]
As is clear from Table 7 and FIG. 14, when the required amount of erbium is dissolved in the β-type nickel oxyhydroxide as the positive electrode active material, the discharge capacity can be improved. It can be seen that the effects of Examples 29 to 36 are greater in Examples 29 to 36 in the range of 0.1 to 3.0% by weight and Comparative Example 8 in the range of 0.05% by weight.
[0112]
Thus, when the solid solution amount of erbium is less than 0.1% by weight, the effect of improving the discharge capacity is not sufficient, and when the amount is 0.1% by weight or more, the effect of improving the discharge capacity is sufficient. It can be understood that it can be obtained.
[0113]
Again, the detailed mechanism has not been elucidated, but when erbium is dissolved in nickel oxyhydroxide, the sites of nickel are replaced by erbium. At that time, erbium has a larger ionic radius than nickel. It is presumed that the solid solution of erbium distorts the crystals of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0114]
In addition, for the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 as exemplified in the representative Examples 29 and 34 and Comparative Example 2, the change in the discharge capacity with respect to the amount of erbium dissolved at a constant current of 1 mA is shown. It is shown in FIG. In this figure, the change characteristic of the discharge capacity of Comparative Example 2 is indicated by a curve 11e, the change characteristic of the discharge capacity of Example 29 is indicated by a curve 72, and the change characteristic of the discharge capacity of Example 34 is indicated by a curve 73. Is shown.
[0115]
As is clear from FIG. 15, when the 1 mA discharge is performed, the discharge characteristics 72 of Example 29 and 34 of Example 34 in which erbium is dissolved as a solid solution compared to the discharge characteristics 11e of Comparative Example 2 in which erbium is not dissolved. It can be seen that the characteristic 73 has a larger discharge capacity, and in that case, it shows that the potential is almost flat near 1.0 to 1.2 V. Further, it can be seen that the discharge capacity is improved by increasing the amount of erbium dissolved.
[0116]
However, the discharge capacity can be improved by increasing the solid solution amount of erbium. However, as described above, erbium has a larger ionic radius than nickel, and therefore, with the current technology, it is 3.0% by weight. Is the limit of solid solution, and if the solid solution of 3.0% by weight or more becomes possible, the present invention includes the range in which the solid solution becomes possible in the sense of increasing the discharge capacity.
[0117]
Further, in the case of Example 36, the discharge capacity at the time of constant current discharge of 1 mA is 85.4 mAh from Table 7, and when this is calculated using the filling amount of the positive electrode active material, the capacity per weight is obtained. Is about 1095 mAh / g (= 85.4 / 0.1 / 0.78), which is a very large value as compared with the conventional battery cathode material.
[0118]
Therefore, when the erbium dissolved in the positive electrode active material is in the range of 0.1 to 3.0% by weight of the β-type nickel oxyhydroxide, the erbium is compared with Comparative Example 2 in which erbium is not dissolved. Since the discharge capacity can be remarkably improved and can be set to a very large value as compared with the conventional cathode material for a battery, the solid solution amount of erbium is 0.1 to 3.0 weight at this stage. % Is preferable.
[0119]
(Examples 37 to 44)
In Examples 37 to 44, β-type nickel oxyhydroxide 8 having a substantially spherical particle shape was used, and the amount of metal compound holmium (Ho) in the range of 0.1 to 3.0% by weight was used. Was changed to form a solid solution. Except for using the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which the amount of holmium was changed to form a solid solution, the preparation of a positive electrode mixture, the formation of a positive electrode pellet 4, the preparation of a negative electrode active material 5, the formation of a separator 6 Regarding the interposition and the like, the coin-type battery 1 was manufactured in the same manner as described in the above embodiment.
[0120]
As a method for producing β-type nickel oxyhydroxide in which holmium is dissolved, for example, an aqueous solution in which nickel sulfate and holmium oxide are mixed at a predetermined ratio, an ammonium supply such as ammonium sulfate, and an alkaline aqueous solution such as sodium hydroxide Are stirred and mixed to produce nickel hydroxide in which holmium is dissolved.
[0121]
The aforementioned holmium-dissolved nickel hydroxide is poured into a mixed solution of an alkaline aqueous solution such as sodium hydroxide and an oxidizing agent such as sodium hypochlorite, and chemically oxidized to form a substantially spherical holmium solid solution. Produce β-type nickel oxyhydroxide. In this case, in short, any other method may be used as long as it can produce β-type nickel oxyhydroxide in which holmium is dissolved.
[0122]
Regarding the solid solution amount of holmium, the total amount of metal elements was quantified by chelate titration, and then trace elements other than nickel were quantified by ICP (high frequency plasma emission analysis).
[0123]
(Comparative Example 9)
Comparative Example 9 is the same as Examples 37 to 44 except that the amount of gadolinium dissolved in the above Examples 37 to 44 was 0.05% by weight, which was 0.1% by weight or less. did.
[0124]
For example, using the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape in which holmium is not dissolved, for example, the comparative example 2 described above and the β-type oxyhydroxide having a substantially spherical particle shape in which a required amount of holmium is dissolved. Table 8 shows the discharge capacities when a 1 mA discharge was performed for Examples 37 to 44 and Comparative Example 9 using nickel hydroxide 8, and the change in the discharge capacities with respect to the holmium (Ho) solid solution amount at this time. As shown in FIG.
[0125]
[Table 8]

[0126]
As is clear from Table 8 and FIG. 16, when a required amount of holmium is dissolved in β-type nickel oxyhydroxide, which is a positive electrode active material, the discharge capacity can be improved. It can be seen that in Examples 37 to 44 in the range of 0.1 to 3.0% by weight and Comparative Example 9 in the range of 0.05% by weight, Examples 37 to 44 have a greater effect.
[0127]
As described above, when the amount of holmium dissolved is less than 0.1% by weight, the effect of improving the discharge capacity is not sufficient. When the amount of holmium is 0.1% by weight or more, the effect of improving the discharge capacity is insufficient. It can be understood that it can be obtained.
[0128]
Although the detailed mechanism has not been elucidated yet, when holmium is dissolved in nickel oxyhydroxide, the site of nickel is replaced by holmium. At that time, holmium has a larger ionic radius than nickel. It is presumed that the solid solution of holmium distorts the crystal of nickel oxyhydroxide, which improves the reactivity with lithium as the negative electrode active material.
[0129]
In addition, for the β-type nickel oxyhydroxide having a substantially spherical particle shape 8 as exemplified in the representative Examples 37 and 42 and Comparative Example 2, the change in the discharge capacity with respect to the solid solution amount of holmium at a constant current of 1 mA is shown. 17 is shown. In this figure, the change characteristic of the discharge capacity of Comparative Example 2 is indicated by a curve 11f, the change characteristic of the discharge capacity of Example 37 is indicated by a curve 82, and the change characteristic of the discharge capacity of Example 42 is indicated by a curve 83. Is shown.
[0130]
As is clear from FIG. 17, when a 1 mA discharge was performed, the discharge characteristics 82 of Example 37 and the discharge of Example 42 in which holmium was dissolved were better than the discharge characteristics 11f of Comparative Example 2 in which holmium was not dissolved. It can be seen that the characteristic 83 has a larger discharge capacity, and at that time, it shows a substantially flat potential around 1.0 to 1.2 V. Further, it can be seen that the discharge capacity is improved by increasing the amount of holmium dissolved.
[0131]
However, the discharge capacity can be improved by increasing the amount of solid solution of holmium. However, as described above, holmium has a larger ionic radius than nickel, and therefore, the current technology has a weight ratio of 3.0% by weight. Is the limit of solid solution, and if the solid solution of 3.0% by weight or more becomes possible, the present invention includes the range in which the solid solution becomes possible in the sense of increasing the discharge capacity.
[0132]
In the case of Example 44, the discharge capacity at the time of 1 mA constant current discharge is 84.3 mAh from Table 8, and when this is calculated using the filling amount of the positive electrode active material, the capacity per weight is obtained. Is about 1081 mAh / g (= 84.3 / 0.1 / 0.78), which is a very large value even when compared with the conventional battery cathode material.
[0133]
Therefore, when holmium dissolved in the positive electrode active material is in the range of 0.1 to 3.0% by weight of the β-type nickel oxyhydroxide, the holmium is compared with Comparative Example 2 in which holmium is not dissolved. Since the discharge capacity can be remarkably improved and can be set to a very large value as compared with a conventional cathode material for a battery, the solid solution amount of holmium is 0.1 to 3.0 wt. % Is preferable.
[0134]
Although the coin-type battery 1 has been described, it is sufficient that the β-type nickel oxyhydroxide 8 having a substantially spherical particle shape is used. Therefore, such a non-aqueous primary battery is limited to the shape of the coin-type battery 1. is not.
[0135]
Further, although not described as an example, for example, even when β-type nickel oxyhydroxide 9 having a rock-like particle shape is used, a required amount of samarium, ytterbium, gadolinium, cerium, erbium, or holmium is dissolved. By doing so, the filling capacity is not changed, but the discharge capacity can be considerably improved as compared with the conventional example in which these metals are not dissolved in a solid solution.In short, the present invention provides the required amounts of samarium and ytterbium. There is a fundamental technical improvement in the solid solution of an element selected from the genus lanthanoids such as gadolinium, cerium, erbium or holmium in β-type nickel oxyhydroxide.
[0136]
【The invention's effect】
As described above, in the nonaqueous primary battery according to the present invention, the positive electrode active material mainly composed of nickel oxyhydroxide and the negative electrode active material composed of light metal are separated by a separator between the positive electrode terminal and the negative electrode terminal. And a non-aqueous electrolyte, wherein the positive electrode active material comprises a lanthanoid element such as samarium, ytterbium, gadolinium, cerium, erbium or holmium in a required amount. Due to the formation of the dissolved β-type nickel oxyhydroxide, the discharge capacity can be remarkably increased, thereby not only reducing the size and weight of the primary battery, but also lowering the operating voltage. It works.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a coin-type battery according to an embodiment of the present invention.
FIG. 2 is an electron microscope photograph of nickel oxyhydroxide having a substantially spherical particle shape used in the embodiment.
FIG. 3 is an electron micrograph of a rock-like (non-spherical) nickel oxyhydroxide used for the battery of Comparative Example 1.
FIG. 4 is a table showing a change in discharge capacity with respect to a solid solution amount of samarium at a constant current of 1 mA and 5 mA in a coin-type battery using a samarium solid solution positive electrode active material according to an embodiment of the present invention.
FIG. 5 is a table showing a change in discharge capacity of a coin-type battery according to Examples 3 and 7 of the present invention and Comparative Example 2 at a constant current of 1 mA.
FIG. 6 is a table showing changes in discharge capacity of a coin-type battery according to Examples 3 and 7 of the present invention and Comparative Example 2 at a constant current of 5 mA.
FIG. 7 is a table showing a change in discharge capacity with respect to the amount of ytterbium dissolved in a coin-type battery using the ytterbium solid solution positive electrode active material according to the embodiment of the present invention at a constant current of 1 mA and 5 mA.
FIG. 8 is a table showing a change in discharge capacity at a constant current of 1 mA for the coin batteries of Examples 8 and 12 of the present invention and Comparative Example 2.
FIG. 9 is a table showing a change in discharge capacity at a constant current of 5 mA for the coin batteries of Examples 8 and 12 of the present invention and Comparative Example 2.
FIG. 10 is a table showing a change in discharge capacity with respect to the amount of gadolinium dissolved in a coin-type battery using a gadolinium solid solution positive electrode active material according to the embodiment of the present invention at a constant current of 1 mA.
FIG. 11 is a table showing changes in discharge capacity of a coin-type battery of Specific Example 15 and Example 20 of the present invention and Comparative Example 2 at a constant current of 1 mA.
FIG. 12 is a table showing a change in discharge capacity with respect to a cerium solid solution amount at a constant current of 1 mA in a coin-type battery using a cerium solid solution positive electrode active material according to an embodiment of the present invention.
FIG. 13 is a table showing changes in discharge capacity at a constant current of 1 mA for the coin-type batteries of Specific Examples 23 and 27 and Comparative Example 2.
FIG. 14 is a table showing a change in discharge capacity with respect to the amount of erbium dissolved at a constant current of 1 mA in a coin-type battery using the erbium-dissolved positive electrode active material according to the embodiment of the present invention.
FIG. 15 is a table showing changes in discharge capacity at a constant current of 1 mA for the coin batteries of Specific Examples 29 and 34 of the present invention and Comparative Example 2.
FIG. 16 is a table showing a change in discharge capacity with respect to the amount of holmium dissolved at a constant current of 1 mA in a coin-type battery using a holmium solid solution positive electrode active material according to an embodiment of the present invention.
FIG. 17 is a table showing a change in discharge capacity at a constant current of 1 mA for the coin batteries of Specific Examples 37 and 42 and Comparative Example 2 of the present invention.
[Explanation of symbols]
1 coin-type battery (non-aqueous primary battery); 2 positive electrode can (positive electrode terminal)
3 negative electrode cup (negative electrode terminal); 4 positive electrode pellet (positive electrode active material)
5 negative electrode active material; 6 separator; 7 sealing gasket
8 β-type nickel oxyhydroxide having a substantially spherical particle shape;
9 Rock-shaped (non-spherical) particle-shaped β-type nickel oxyhydroxide
11a to 11f, 21a, 21b Discharge Characteristics of Comparative Example 2
12, 22 Discharge characteristics of Example 3; 13, 23 Discharge characteristics of Example 7
32, 42 Discharge characteristics of Example 8; 33, 43 Discharge characteristics of Example 12
52 discharge characteristics of Example 15; 53 discharge characteristics of Example 20
62 Discharge characteristics of Example 23; 63 Discharge characteristics of Example 27
72 discharge characteristics of Example 29; 73 discharge characteristics of Example 34
82 Discharge Characteristics of Example 37; 83 Discharge Characteristics of Example 42

Claims (10)

Between a positive electrode terminal and a negative electrode terminal, a positive electrode active material containing nickel oxyhydroxide as a main component and a negative electrode active material composed of a light metal are separately disposed by a separator, and a primary battery having a nonaqueous electrolyte is provided. So,
A non-aqueous primary battery, wherein the positive electrode active material is formed of β-type nickel oxyhydroxide in which a required amount of an element selected from the group consisting of lanthanoids is dissolved. The element selected from the lanthanoid genus,
The non-aqueous primary battery according to claim 1, wherein the primary battery is one of samarium, ytterbium, gadolinium, cerium, erbium, and holmium. The solid solution amount of the element dissolved in the positive electrode active material is 0.1% by weight or more of β-type nickel oxyhydroxide in the case of samarium,
0.2% by weight or more of β-type nickel oxyhydroxide in the case of ytterbium;
In the case of gadolinium, it is 0.1% by weight or more of β-type nickel oxyhydroxide,
0.2% by weight or more of β-type nickel oxyhydroxide in the case of cerium,
In the case of erbium, it is 0.1% by weight or more of β-type nickel oxyhydroxide,
The non-aqueous primary battery according to claim 1, wherein the amount of holmium is 0.1% by weight or more of β-type nickel oxyhydroxide. Β-type nickel oxyhydroxide of the positive electrode active material,
4. The non-aqueous primary battery according to claim 1, wherein the non-aqueous primary battery is formed into substantially spherical particles. The light metal of the negative electrode active material,
The non-aqueous primary battery according to claim 1, wherein the battery is any one of lithium, a lithium alloy, magnesium, sodium, potassium, calcium, and aluminum. 2. The non-aqueous primary battery according to claim 1, wherein the non-aqueous primary battery exhibits a substantially flat potential near 1.0 to 1.2V. A method for producing an active material used as a positive electrode active material of a battery,
A step of mixing sulfuric acid or nickel nitrate and a metal compound in an aqueous solution; and a step of stirring and mixing an ammonium ion donor and an aqueous alkali solution to produce nickel solid solution metal hydroxide,
An alkaline aqueous solution and a mixed solution of an oxidizing agent are mixed with the required amount of an element selected from the group consisting of lanthanoids to form a solid solution of nickel hydroxide, and chemically oxidized to obtain nickel oxyhydroxide. Of producing active materials for batteries. The element selected from the lanthanoid genus,
The method according to claim 7, wherein the active material is one of samarium, ytterbium, gadolinium, cerium, erbium, and holmium. The solid solution amount of the element dissolved in the positive electrode active material is 0.1% by weight or more of β-type nickel oxyhydroxide in the case of samarium,
0.2% by weight or more of β-type nickel oxyhydroxide in the case of ytterbium;
In the case of gadolinium, it is 0.1% by weight or more of β-type nickel oxyhydroxide,
0.2% by weight or more of β-type nickel oxyhydroxide in the case of cerium,
In the case of erbium, it is 0.1% by weight or more of β-type nickel oxyhydroxide,
9. The method for producing an active material for a battery according to claim 7, wherein the amount of holmium is 0.1% by weight or more of the β-type nickel oxyhydroxide. Β-type nickel oxyhydroxide of the positive electrode active material,
The method for producing a battery active material according to claim 7, wherein the active material is formed into substantially spherical particles.

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