JP4056271B2 - Electrode material manufacturing method, electrode material and non-aqueous electrolyte battery - Google Patents

Description

【００５２】
得られた立方晶マンガンスピネル１ｇを１０ｍＬの電解液中にいれ、６０℃で１０日間保存した。保存の前後にマンガンスピネルのＸ線回折測定ならびにＲｉｅｔｖｅｌｄ解析を行い、その格子定数の変化を測定した。そして、｛（保存後の格子定数）−（保存前の格子定数）｝÷（保存前の格子定数）×１００（％）を格子定数変化率とした。格子定数変化率を表２に示す。また、６０℃で保存前のマンガンスピネルの格子定数の測定結果を表３に示す。
【００５３】
【表２】

【００５４】
【表３】

【００５５】
《比較例２》
８００℃での焼成を酸素分圧０．９ａｔｍの雰囲気中で行ったこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００５６】
《比較例３》
８００℃での焼成を酸素分圧０．８ａｔｍの雰囲気中で行ったこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００５７】
《比較例４》
８００℃での焼成を酸素分圧０．７ａｔｍの雰囲気中で行ったこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００５８】
《比較例５》
８００℃での焼成を空気中で行ったこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００５９】
《比較例６》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９０：１０になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９０：１０になるように混合したこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００６０】
《比較例７》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９３：７になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９３：７になるように混合したこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６１】
《比較例８》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９５：５になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９５：５になるように混合したこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６２】
《比較例９》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９８：２になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９８：２になるように混合したこと以外は、比較例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６３】
《比較例１０》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９０：１０になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９０：１０になるように混合したこと以外は、比較例４と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００６４】
《比較例１１》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９３：７になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９３：７になるように混合したこと以外は、比較例４と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す
【００６５】
《比較例１２》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９５：５になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９５：５になるように混合したこと以外は、比較例４と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６６】
《比較例１３》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９８：２になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９８：２になるように混合したこと以外は、比較例４と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６７】
《比較例１４》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９０：１０になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９０：１０になるように混合したこと以外は、比較例５と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６８】
《比較例１５》
原料混合物に、塩基性炭酸マグネシウムをリチウムとマグネシウムとのモル比が９５：５になるように、また、水酸化アルミニウムをマンガンとアルミニウムとのモル比が９５：５になるように混合したこと以外は、比較例５と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００６９】
《実施例１》
塩基性炭酸マグネシウムと水酸化アルミニウムとを、マグネシウムとアルミニウムのモル比が１：２になるように秤量し、自動乳鉢で５時間混合して、ペレット状に成形した。ペレットを空気中１４００℃で５時間焼成した後、自動乳鉢で５時間粉砕・混合し、粉体を得た。粉体を再度ペレット状に成形し、そのペレットを空気中１４００℃で５時間焼成してＭｇＡｌ₂Ｏ₄を合成した。
【００７０】
炭酸リチウムと二酸化マンガンとを、リチウムとマンガンのモル比が１：２になるように秤量し、自動乳鉢で５時間混合してペレット状に成形し、そのペレットを５５０℃で１２時間か焼した。
これにリチウムとマグネシウムとのモル比が９０：１０になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物を再びペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で１２時間焼成し、マンガンスピネルを得た。
得られたマンガンスピネルのＸ線回折測定を行ったところ、ＭｇＡｌ₂Ｏ₄に帰属されるピークは観測されなかった。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。また、６０℃で保存前のマンガンスピネルの格子定数の測定結果を表３に示す。
【００７１】
《実施例２》
リチウムとマグネシウムのモル比が９５：５になるようにＭｇＡｌ₂Ｏ₄を含む原料混合物を用いたこと以外は、実施例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００７２】
《実施例３》
リチウムとマグネシウムのモル比が９８：２になるようにＭｇＡｌ₂Ｏ₄を含む原料混合物を用いたこと以外は、実施例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００７３】
《実施例４》
８００℃での焼成を酸素分圧０．７ａｔｍの雰囲気で行ったこと以外は、実施例１と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、比較例１と同様の方法で格子定数変化率を測定した結果を表２に示す。
【００７４】
《実施例５》
８００℃での焼成を酸素分圧０．７ａｔｍの雰囲気で行ったこと以外は、実施例２と同様の合成を行った。比較例１と同様の方法で充放電試験を行った結果を表１に示す。
【００７５】
《実施例６》
実施例１と同様の方法でＭｇＡｌ₂Ｏ₄を合成した。
炭酸リチウムと二酸化マンガンとを、リチウムとマンガンのモル比が１：２になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼し、その後、ペレットを自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で１１．５時間焼成した。
この焼成物に対し、リチウムとマグネシウムのモル比が９０：１０になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間粉砕・混合し、粉体混合物を得た。この粉体混合物をペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で０．５時間焼成し、マンガンスピネルを得た。
得られたマンガンスピネルのＸ線回折測定を行ったところ、ＭｇＡｌ₂Ｏ₄に帰属されるピークが観測された。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、Ｘ線回折測定ならびにＲｉｅｔｖｅｌｄ解析を行い、格子定数を求めた結果を表３に示す。
【００７６】
《実施例７》
実施例１と同様の方法でＭｇＡｌ₂Ｏ₄を合成した。
炭酸リチウムと二酸化マンガンとを、リチウムとマンガンのモル比が１：２になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼し、その後、ペレットを自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、ペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で９時間焼成した。
この焼成物に対し、リチウムとマグネシウムのモル比が９０：１０になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間粉砕・混合し、粉体混合物を得た。この粉体混合物をペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で３時間焼成し、マンガンスピネルを得た。
得られたマンガンスピネルのＸ線回折測定を行ったところ、ＭｇＡｌ₂Ｏ₄に帰属されるピークが観測された。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、Ｘ線回折測定ならびにＲｉｅｔｖｅｌｄ解析を行い、格子定数を求めた結果を表３に示す。
【００７７】
《実施例８》
実施例１と同様の方法でＭｇＡｌ₂Ｏ₄を合成した。
炭酸リチウムと二酸化マンガンとを、リチウムとマンガンのモル比が１：２になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼し、その後、ペレットを自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、ペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で６時間焼成した。
この焼成物に対し、リチウムとマグネシウムのモル比が９０：１０になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間粉砕・混合し、粉体混合物を得た。この粉体混合物をペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で６時間焼成し、マンガンスピネルを得た。
得られたマンガンスピネルのＸ線回折測定を行ったところ、ＭｇＡｌ₂Ｏ₄に帰属されるピークは観測されなかった。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、Ｘ線回折測定ならびにＲｉｅｔｖｅｌｄ解析を行い、格子定数を求めた結果を表３に示す。
【００７８】
《実施例９》
実施例１と同様の方法でＭｇＡｌ₂Ｏ₄を合成した。
炭酸リチウムと二酸化マンガンとを、リチウムとマンガンのモル比が１：２になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼し、その後、ペレットを自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、ペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で３時間焼成した。
この焼成物に対し、リチウムとマグネシウムのモル比が９０：１０になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間粉砕・混合し、粉体混合物を得た。この粉体混合物をペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で９時間焼成し、マンガンスピネルを得た。
得られたマンガンスピネルのＸ線回折測定を行ったところ、ＭｇＡｌ₂Ｏ₄に帰属されるピークは観測されなかった。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果を表１に示す。また、Ｘ線回折測定ならびにＲｉｅｔｖｅｌｄ解析を行い、格子定数を求めた結果を表３に示す。
【００７９】
表１の結果より以下のことが理解できる。
実施例１〜５からは、マンガンスピネルの原料にＭｇＡｌ₂Ｏ₄を含ませると、マンガンスピネルの原料にＭｇＡｌ₂Ｏ₄の原料を含ませた場合よりも、さらに容量維持率が高くなることがわかる。この効果は、予め合成されたＭｇＡｌ₂Ｏ₄をマンガンスピネルに分散させた場合には、分散したＭｇＡｌ₂Ｏ₄が微細ながらもその結晶構造を保持していることに由来すると考えられる。すなわち、マンガンスピネルの結晶を安定化させる微細なＭｇＡｌ₂Ｏ₄粒子が、効率よくマンガンスピネルのマトリックス中に分散していると考えられる。一方、マンガンスピネルの原料にＭｇＡｌ₂Ｏ₄の原料を含ませた場合には、マンガンスピネルの結晶を安定化させる微細なＭｇＡｌ₂Ｏ₄粒子の形成が効率よく行われないものと考えられる。
【００８０】
実施例１および実施例６〜９を比較すると、マンガンスピネルの原料とＭｇＡｌ₂Ｏ₄との８００℃での反応時間が長いほど、初期容量が小さくなることがわかる。Ｌｉの存在量は、全ての試料について等しいにもかかわらず、反応時間が長くなるほど容量が減少するのは、Ｍｇ、ＡｌがＬｉＭｎ₂Ｏ₄に固溶するにつれて、利用できないＬｉが増加する傾向にあることを示している。
【００８１】
また、実施例６〜９からは、マンガンスピネルの原料とＭｇＡｌ₂Ｏ₄との反応時間が長いほど、初期容量は低下するものの、容量維持率が高くなることがわかる。なお、反応時間が比較的短い場合にも優れた容量維持率が得られるのは、母相であるマンガンスピネルと、そのマトリックス中に島状で分散しているＭｇＡｌ₂Ｏ₄との間に形成される中間相の構造が、マンガンスピネルの結晶を安定化させる微細なＭｇＡｌ₂Ｏ₄粒子と同等の作用を有するためと考えられる。このような中間相の存在は、微小部Ｘ線回折測定により確認されている。
【００８２】
表２の結果より以下のことが理解できる。
容量維持率が９５％以上の実施例１および４では、格子定数変化率が極めて小さいのに対し、容量維持率が９２％の比較例６および９０％未満の比較例１〜４および１０では、格子定数変化率が大きな値を示している。このことは、比較例の電極材料は６０℃での保存時に構造変化が大きいこと、ならびに実施例１および４の電極材料はほとんど構造変化していないことを示唆している。ＭｇＡｌ₂Ｏ₄粒子がマトリックス中に均一に分散し、共通の酸素骨格を介して電極材料の結晶構造を安定化することにより、サイクル特性および高温保存特性が向上したものと考えられる。
【００８３】
表３の結果をプロットした結果を図１に示す。横軸には、ＬｉおよびＭｎの原料と、ＭｇＡｌ₂Ｏ₄との８００℃での反応時間を示す。縦軸には、マンガンスピネルの格子定数を示す。ＬｉおよびＭｎの原料とＭｇＡｌ₂Ｏ₄とを８００℃で９時間以上反応させた試料においては、格子定数が一定になったことから、ＭｇＡｌ₂Ｏ₄が完全に反応してマンガンスピネル中に固溶したものと考えられる。
すなわち、本発明によれば、別のスピネル成分であるＭｇＡｌ₂Ｏ₄の出発原料としてＭｇＡｌ₂Ｏ₄そのものを用いているため、ＭｇＡｌ₂Ｏ₄を原子レベルの高分散状態でマンガンスピネルに包含させることができる。そのため、マンガンスピネル中に別のスピネル成分由来のＭｇ−Ｏ−Ａｌ結合が多数存在し、電極材料の結晶構造が大きく安定化されたものと考えられる。
一方、従来の技術では、アルミニウムとマグネシウムが原子レベルで均一に存在するマンガンスピネルを得ることはできない。すなわち、アルミニウムによるマンガンの置換に偏った領域と、マグネシウムによるリチウムの置換に偏った領域とが存在するため、別のスピネル成分であるＭｇＡｌ₂Ｏ₄が原子レベルの高分散状態でマンガンスピネルに包含されているとは言い難い。従って、マンガンスピネル中の別のスピネル成分由来のＭｇ−Ｏ−Ａｌ結合が少なく、電極材料の結晶構造の安定化が不充分になるものと考えられる。
【００８４】
《実施例１０》
塩基性炭酸マグネシウムと酸化ガリウムとを、マグネシウムとガリウムとのモル比が１：２になるように秤量し、これらを自動乳鉢で５時間混合し、ペレット状に成形した。このペレットを空気中で１４００℃で５時間焼成した後、自動乳鉢で５時間粉砕し、再度ペレット状に成形した。このペレットを空気中で１４００℃で５時間焼成して、ＭｇＧａ₂Ｏ₄を合成した。こうして得られたＭｇＧａ₂Ｏ₄をＭｇＡｌ₂Ｏ₄の代わりに用いたこと以外、実施例１と同様にしてマンガンスピネルを得た。
得られたマンガンスピネルを用いて比較例１と同様の方法で充放電試験を行った結果、初期容量は９３ｍＡｈ／ｇ、容量維持率は９７％であった。
この結果から、ＭｇＡｌ₂Ｏ₄以外の別のスピネル成分をマンガンスピネルに分散させた場合にも、別のスピネル成分を分散させることなく合成した比較例１のマンガンスピネルの場合に比べて、容量維持率が高くなることがわかる。
【００８５】
《実施例１１》
実施例１と同様の方法でＭｇＡｌ₂Ｏ₄を合成した。
炭酸リチウムと、酸化クロムと、二酸化マンガンとを、リチウムとクロムとマンガンとのモル比が１：０．４：１．６になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼した。
これにリチウムとマグネシウムとのモル比が９５：５になるようにＭｇＡｌ₂Ｏ₄を添加した後、自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で１２時間焼成し、マンガンスピネルを得た。
電圧範囲を４．２〜３．５Ｖとしたこと以外、比較例１と同様の方法で充放電試験を行った結果、初期容量は６３ｍＡｈ／ｇ、容量維持率は９８％であった。
【００８６】
《比較例１６》
炭酸リチウムと、酸化クロムと、二酸化マンガンとを、リチウムとクロムとマンガンとのモル比が１：０．４：１．６になるように秤量した後、自動乳鉢で５時間混合して原料混合物を得た。次いで、原料混合物をペレット状に成形して５５０℃で１２時間か焼した後、自動乳鉢で５時間粉砕・混合し、粉体を得た。この粉体を再度ペレット状に成形し、そのペレットを酸素分圧１．０ａｔｍの雰囲気中８００℃で１２時間焼成し、マンガンスピネルを得た。
電圧範囲を４．２〜３．５Ｖとしたこと以外、比較例１と同様の方法で充放電試験を行った結果、初期容量は７０ｍＡｈ／ｇ、容量維持率は８３％であった。実施例１１と比較例１６との比較から、ＭｇＡｌ₂Ｏ₄を分散させることなく合成した比較例１６のマンガンスピネルの場合に比べて、ＭｇＡｌ₂Ｏ₄を分散させて合成した実施例１１のマンガンスピネルを用いた場合の方が、容量維持率が高くなることがわかる。このことは、種々の組成のマンガンスピネルに別のスピネル成分を分散させた場合、いずれの組成のマンガンスピネルにおいても同様の容量維持率の向上効果が得られることを示唆している。
【００８７】
【発明の効果】
以上説明したように、本発明によれば、高温保存性、サイクル特性等に優れた電極材料を得ることができる。この電極材料を用いた非水電解質二次電池は、特に高温での特性が従来に比べて向上する。
【図面の簡単な説明】
【図１】ＬｉおよびＭｎの原料とＭｇＡｌ₂Ｏ₄との８００℃での反応時間と、マンガンスピネルの格子定数との関係を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an electrode material used for a nonaqueous electrolyte battery. The present invention particularly relates to a non-aqueous electrolyte secondary battery with improved storage properties and charge / discharge cycle life. The present invention can be applied to a non-aqueous electrolyte secondary battery used in a portable information terminal, a portable electronic device, a small household electric power storage device, a motorcycle using a motor as a power source, an electric vehicle, a hybrid electric vehicle, and the like.
[0002]
[Prior art]
In recent years, lithium secondary batteries used as a main power source for mobile communication devices, portable electronic devices, and the like are characterized by high electromotive force and high energy density. A lithium secondary battery using lithium metal as a negative electrode material has a high energy density, but dendrites are deposited on the negative electrode during charging, and the battery may break through the separator and repeatedly reach the positive electrode side by repeated charge and discharge, causing an internal short circuit. is there. Further, the deposited dendrite has a high specific surface area and thus has a high reaction activity, and reacts with the solvent in the electrolytic solution on the surface to form an interface film lacking electronic conductivity, so that the internal resistance of the battery tends to be high. In addition, isolated particles may be generated from the electron conduction network, and these are factors that reduce charge and discharge efficiency. For these reasons, a lithium secondary battery using lithium metal as a negative electrode material has low reliability and a short cycle life.
[0003]
Currently, as a negative electrode material replacing lithium metal, a carbon material capable of occluding and releasing lithium ions or a spinel oxide containing a transition metal is used and has been put into practical use. Usually, since these materials do not deposit metallic lithium, the problem of internal short circuit due to dendrite does not occur.
[0004]
On the other hand, the positive electrode material includes lithium cobalt oxide (LiCoO₂), Lithium nickelate (LiNiO)₂), Spinel type lithium manganate (LiMn)₂O_Four(Hereinafter referred to as manganese spinel), etc., and some of them have been put into practical use. Since these active materials have a potential of about 4 V with respect to lithium, a battery having a high energy density can be provided. The theoretical capacity is about 280 mAh / g for lithium cobaltate and lithium nickelate, whereas it is as small as 148 mAh / g for manganese spinel. However, manganese spinel is rich in manganese oxide as a raw material, is inexpensive, and has a relatively good thermal stability during charging, so it can be used in various applications such as small consumer appliances or EVs (electric vehicles). Is expected.
[0005]
[Problems to be solved by the invention]
However, when a battery containing manganese spinel is stored particularly in a high temperature environment, manganese is eluted into the electrolyte solution, so that there is a problem that storage characteristics and cycle characteristics are impaired.
In order to improve this problem, a method has been attempted in which a part of octahedral sites mainly occupied by manganese is substituted with other elements. For example, substitution with transition metal elements such as cobalt and chromium, partial substitution of manganese sites with lithium by adding lithium in excess of the stoichiometric amount when charging raw materials, substitution with typical elements such as aluminum and magnesium have been attempted. . Certainly, these material modifications have improved storage characteristics and cycle characteristics at high temperatures, but have not reached a practically sufficient level.
[0006]
The reason why the high-temperature storage characteristics and the like are improved is that a part of manganese occupying the octahedral site is replaced with a solid solution element, so that the crystal phase constituted through the common oxygen arrangement is stabilized, and the manganese This is considered to be because elution is suppressed. However, practically sufficient characteristics cannot be obtained in a state where these substitution elements occupy the octahedral sites of the spinel skeleton on average and each adjacent tetrahedral site is mainly occupied by lithium. This is probably because of this. That is, it is considered that the substitution element contributing to the stabilization of the crystal structure does not exist simultaneously at the octahedral site and the tetrahedral site of the constituent unit of the spinel skeleton.
[0007]
The main object of the present invention is to suppress elution of manganese into an electrolytic solution in an electrode material for a nonaqueous electrolyte battery, particularly when manganese spinel is used as a positive electrode active material. That is, an object of the present invention is to provide a manganese spinel material having excellent storage characteristics and cycle characteristics, particularly high temperature storage characteristics and cycle characteristics, and at the same time providing a nonaqueous electrolyte battery using the same.
However, the technical idea of the present invention is not limited to the manganese spinel material, and is composed of an electrochemically highly active phase and an electrochemically low active phase, and is commonly used for electrode materials that stabilize the highly active phase by the low active phase. To do.
Therefore, the present invention provides not only a manganese spinel material, but also a wide range of electrode materials that are composed of an electrochemically high active phase and an electrochemically low active phase, and that are excellent in high temperature storage characteristics, cycle characteristics, and the like. For the purpose.
[0008]
[Means for Solving the Problems]
JP-A-2000-176513 discloses that, for the above-described purpose, another spinel component composed of a combination of different elements is included in the crystal phase of the spinel-type lithium-containing transition metal oxide via a common oxygen arrangement. Has proposed. Here, another spinel component has the effect | action which stabilizes the crystal structure of a spinel type lithium containing transition metal oxide.
In this publication, a mixture of lithium carbonate, electrolytic manganese dioxide, basic magnesium carbonate, and aluminum hydroxide is formed into a pellet and then fired at a high temperature to produce an electrode material.
However, in the electrode material manufactured by such a method, aluminum and magnesium are not uniformly present at the atomic level in the manganese spinel crystal. In this case, there are a region biased toward the replacement of manganese with aluminum and a region biased toward the replacement of lithium with magnesium. Therefore, MgAl, another spinel component that contributes to the stabilization of the structure of the electrode material₂O_FourIs not included in the manganese spinel matrix in a highly dispersed state at the atomic level. That is, another spinel component is not sufficiently formed, and the influence of another spinel component on the manganese spinel is small, so that the crystal structure of the electrode material is not sufficiently stabilized.
[0009]
  In view of this point, the present invention is a further improvement of the electrode material proposed in Japanese Patent Laid-Open No. 2000-176513.
  That is, the present invention includes (1) a step of preparing a lithium-containing transition metal oxide a having a spinel crystal structure or a raw material thereof, and (2) a lithium-containing transition metal oxide a or a raw material thereof, and a lithium-containing transition metal. A step of mixing a typical element oxide b that is electrochemically less active than the oxide a, and (3) a step of firing the mixture obtained in the step (2).The typical element oxide b has a spinel crystal structure.The present invention relates to a method for manufacturing an electrode material.
[0010]
  The typical element oxide b is preferably an oxide containing at least one element selected from the group consisting of Group 2, 12, 13, 14, and 15 elements of the periodic table (IUPAC). BetterYes.
ClassicType element oxide b includes MgAl₂O_FourIs preferably used.
  In the step (3), the mixture is preferably fired at 600 to 1000 ° C. The firing time is preferably 24 hours or less.
[0011]
  The present invention also relates to an electrode material produced by the above method.
  The present invention includes, for example, a phase A composed of a lithium-containing transition metal oxide a having a spinel crystal structure and a phase B composed of a typical element oxide b that is electrochemically less active than the lithium-containing transition metal oxide a. Phase B is dispersed in phase A, and an interface between phase A and phase B has an intermediate phase C composed of at least one of the constituent elements of phase A or phase B.The typical element oxide b has a spinel crystal structure, and the intermediate layer C is formed by mutual diffusion of the constituent element of the phase A and the constituent element of the phase B at the interface between the phase A and the phase B. IsThe present invention relates to an electrode material.
  Here, it is preferable that the phase B and the intermediate phase C have an atomic arrangement common to at least one atomic arrangement of the constituent elements of the phase A.Yes.
During ~At least one of the constituent elements of the interphase C preferably has a concentration gradient from the phase A to the phase B in the intermediate phase C.
  The present invention further relates to a non-aqueous electrolyte battery having a non-aqueous electrolyte and the above electrode material.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The idea of the present invention is that an electrochemically stable and different chemical composition is added to phase A (highly active phase A) comprising a spinel-type lithium-containing transition metal oxide a which is electrochemically highly active and unstable in structure. Including the phase B (low active phase B) composed of the typical element oxide b is to stabilize the unstable transition metal oxide a.
[0013]
In other words, the conventional technique attempted to stabilize the spinel crystal phase through the common oxygen arrangement by partially replacing a part of manganese in the octahedral site of the transition metal oxide a with a solid solution element. On the other hand, the present invention is characterized in that the fine particles of the typical element oxide b are dispersed in the transition metal oxide a. According to such a structure, the spinel skeleton of the transition metal oxide a surrounding it can be stabilized by the stability of the skeleton of the typical element oxide b.
[0014]
The composition of the transition metal oxide a is not limited as long as it has a spinel crystal structure. For example, in the case of lithium manganese oxide, LiMn having a molar ratio of lithium to manganese of 1: 2.₂O_FourLi with a molar ratio of lithium to manganese of 1.2: 1.8_1.2Mn_1.8O_FourAnd LiMn having a molar ratio of lithium, manganese and nickel of 1: 1.6: 0.4_1.6Ni_0.4O_FourIn any of these cases, the stabilization effect can be expected.
[0015]
In general, an oxide having a spinel crystal structure is AB.₂O_FourIn some cases, A is a divalent cation and B is a trivalent cation, or A is a tetravalent cation and B is a divalent cation. At this time, the distribution of cations includes (1) a positive spinel structure in which A ions are arranged at tetrahedral sites and B ions are arranged at octahedral sites: (A) [B₂] O_Four(2) Reverse spinel structure in which half of B ions are arranged at tetrahedral sites and the other half of B ions and A ions are arranged randomly at octahedral sites: (B) [AB] O_Four(3) An intermediate spinel structure taking an intermediate arrangement between a normal spinel and a reverse spinel: (A_x・ B_1-x) [A_1-x・ B_{1 + x}] O_Four(0 <x <1). Here, the small parenthesis represents a tetrahedral site, and the large bracket represents an octahedral site.
[0016]
The spinel crystal structure referred to in the present invention includes all of a normal spinel structure, a reverse spinel structure, and an intermediate spinel structure. Further, the spinel structure may belong to any of cubic, tetragonal, hexagonal, trigonal, orthorhombic, monoclinic and triclinic, but particularly cubic and Those belonging to the tetragonal system are preferred.
[0017]
  The method for producing an electrode material of the present invention includes a step (1) of preparing a lithium-containing transition metal oxide a having a spinel crystal structure or a raw material thereof, a lithium-containing transition metal oxide a or a raw material thereof, and a lithium-containing transition. A step (2) of mixing a typical element oxide b that is electrochemically less active than the metal oxide a, and a step (3) of firing the mixture obtained in the step (2).The typical element oxide b has a spinel crystal structure.To do.
[0018]
In the step (1), a lithium salt and a transition metal salt are usually used as a raw material for the lithium-containing transition metal oxide a, but the process from the lithium salt and the transition metal salt to the lithium-containing transition metal oxide a is performed. The intermediate obtained in (1) is also included in the raw material. Specifically, only the raw material of the transition metal oxide a may be fired and reacted to some extent to prepare an intermediate, and then the intermediate and the typical element oxide b may be mixed and further fired. .
[0019]
As the lithium salt, lithium carbonate, lithium nitrate, lithium hydroxide, lithium oxide, or the like can be used.
[0020]
The transition metal salt varies depending on the type of the desired transition metal oxide a. LiMn as transition metal oxide a₂O_FourFor example, manganese dioxide can be used as the transition metal salt.
[0021]
The electrode material of the present invention comprises a transition metal oxide a and a typical element oxide b in a molar ratio of 99.9: 0.1 to 50:50, and further 98: 2 to 90:10. It is preferable to include. What is necessary is just to select the preparation composition of a raw material according to a desired electrode material.
[0022]
The typical element oxide b used in the step (2) includes at least one selected from the group consisting of typical elements of Group 2, 12, 13, 13, 14 and 15 of the periodic table, and further two or more. It is preferable to use an oxide containing the same. Many typical elements have an effect of stabilizing the structure of the transition metal oxide because the valence does not change when lithium is inserted into or extracted from the electrode material.
[0023]
  Typical element oxide b is, SuHas pinel structureAndFor example, an oxide containing magnesium and aluminum in a molar ratio of 1: 2, an oxide containing magnesium and gallium in a molar ratio of 1: 2, an oxide containing magnesium and indium in a molar ratio of 1: 2, and a molar ratio of calcium and indium. An oxide comprising 1: 2; an oxide comprising barium and indium in a molar ratio 1: 2; an oxide comprising strontium and indium in a molar ratio 1: 2; an oxide comprising magnesium and tin in a molar ratio 2: 1; Examples thereof include an oxide containing magnesium, aluminum and gallium in a molar ratio of 1: 1: 1, and an oxide containing magnesium, aluminum and gallium in a molar ratio of 1: 1.2: 0.8. These typical element oxides may be used alone or in combination of two or more. MgAl, the origin of the name of the spinel compound₂O_FourIs widely known as a chemically very stable material and is particularly suitable.The
[0024]
In step (3), the mixture obtained in step (2) is baked. The firing temperature is preferably in the range of 600 to 1000 ° C, particularly 700 to 900 ° C. The firing time is preferably 24 hours or less, particularly preferably in the range of 0.5 to 12 hours. From the viewpoint of obtaining an electrode material having excellent storage characteristics and cycle characteristics at high temperatures, it is preferable to sufficiently react the mixture in step (3). Although the particle size of the low active phase B dispersed in the high active phase A of the electrode material to be produced varies depending on the reaction conditions in the step (3), the particle size of the low active phase B is preferably as small as possible. Specifically, it is preferable that fine particles of typical element oxide b of 0.1 μm or less, further 0.001 μm or less, are island-shaped and dispersed in the matrix of transition metal oxide a. Even if the reaction is sufficiently performed, the crystals of the typical element oxide b once formed do not disappear completely, so that the fine particles or the skeleton of the typical element oxide b are in the matrix of the transition metal oxide a. Maintained.
[0025]
In the case of the production method of the present invention, since the crystal of the typical element oxide b is used as a raw material, in the vicinity of the interface between the high active phase A and the low active phase B, the constituent elements of the high active phase A and the low active phase B The intermediate phase C is formed by mutual diffusion of the constituent elements. Since the intermediate phase C is formed by mutual diffusion of constituent elements of each phase, the constituent elements of the intermediate phase C often have a concentration gradient from the high active phase A to the low active phase B. It is considered that the intermediate phase C adjacent to both the high active phase A and the low active phase B contributes to the stabilization of the high active phase A. In addition, it is considered that the structure of the intermediate phase C is an inclined structure in which the composition and structure continuously change from the typical element oxide b to the transition metal oxide a.
[0026]
The firing atmosphere is not particularly limited. For example, firing can be performed in an atmosphere having an oxygen partial pressure of 0.01 to 0.2 MPa (0.1 to 2 atm).
[0027]
Here, an example of modification of manganese spinel, which is a positive electrode material, has been described. Even in the case of a titanium-based spinel material that is capable of occluding and releasing lithium, there is no problem of elution of titanium. From the viewpoint of reversibility, the same concept holds for improving cycle characteristics.
[0028]
The negative electrode conductive agent used in the present invention may be anything as long as it is an electron conductive material. For example, natural graphite (such as flake graphite), artificial graphite, graphite such as expanded graphite, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon fiber, metal fiber Conductive fibers such as copper, metal powders such as copper and nickel, and organic conductive materials such as polyphenylene derivatives can be contained alone or as a mixture thereof.
[0029]
Among these conductive agents, artificial graphite, acetylene black, and carbon fiber are particularly preferable. Although the addition amount of a electrically conductive agent is not specifically limited, 1-50 weight% is preferable with respect to negative electrode material, and 1-30 weight% is especially preferable. Further, when the negative electrode material itself has electronic conductivity, it can function as a battery without adding a conductive agent.
[0030]
The negative electrode binder used in the present invention may be either a thermoplastic resin or a thermosetting resin. Preferred binders in the present invention include, for example, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, styrene butadiene rubber, tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, Vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride- Hexafluoropropylene - tetrafluoroethylene copolymer, vinylidene fluoride - perfluoromethyl vinyl ether - tetrafluoroethylene copolymer, ethylene - acrylic acid copolymer or (Na⁺) Ion-crosslinked product, ethylene-methacrylic acid copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl acrylate copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl methacrylate copolymer or (Na⁺) An ionic crosslinked body can be mentioned, and these materials can be used alone or as a mixture.
[0031]
Among these materials, more preferable materials are styrene butadiene rubber, polyvinylidene fluoride, ethylene-acrylic acid copolymer, or (Na⁺) Ion-crosslinked product, ethylene-methacrylic acid copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl acrylate copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl methacrylate copolymer or (Na⁺) An ionic cross-linked product.
[0032]
The negative electrode current collector used in the present invention may be anything as long as it is an electronic conductor that does not cause a chemical change in the constructed battery. For example, in addition to stainless steel, nickel, copper, titanium, carbon, conductive resin, etc., materials obtained by treating the surface of copper or stainless steel with carbon, nickel, or titanium are used. In particular, copper or a copper alloy is preferable. The surface of these materials can be oxidized and used. Further, it is desirable to make the current collector surface uneven by surface treatment. As the shape, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like are used in addition to the foil. The thickness is not particularly limited, but a thickness of 1 to 500 μm is used.
[0033]
The conductive agent for positive electrode used in the present invention may be anything as long as it is an electron conductive material that does not cause a chemical change at the charge / discharge potential of the positive electrode material used. For example, graphite such as natural graphite (such as flake graphite), artificial graphite, carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and conductive such as carbon fiber and metal fiber Conductive fibers, metal powders such as carbon fluoride and aluminum, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide, or organic conductive materials such as polyphenylene derivatives, etc. It can be included as a mixture thereof. Among these conductive agents, artificial graphite and acetylene black are particularly preferable. Although the addition amount of a electrically conductive agent is not specifically limited, 1-50 weight% is preferable with respect to positive electrode material, and 1-30 weight% is especially preferable. In the case of carbon or graphite, 2 to 15% by weight is particularly preferable.
[0034]
The positive electrode binder used in the present invention may be either a thermoplastic resin or a thermosetting resin. Preferred binders in the present invention include, for example, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, styrene butadiene rubber, tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer. Polymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoro Ethylene, vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride- Hexafluoropropylene - tetrafluoroethylene copolymer, vinylidene fluoride - perfluoromethyl vinyl ether - tetrafluoroethylene copolymer, ethylene - acrylic acid copolymer or (Na⁺) Ion-crosslinked product, ethylene-methacrylic acid copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl acrylate copolymer or (Na⁺) Ionic cross-linked product, ethylene-methyl methacrylate copolymer or (Na⁺) An ionic crosslinked body can be mentioned, and these materials can be used alone or as a mixture. Of these materials, more preferred are polyvinylidene fluoride and polytetrafluoroethylene.
[0035]
The positive electrode current collector used in the present invention may be any electronic conductor that does not cause a chemical change in the charge / discharge potential of the positive electrode material used. For example, in addition to stainless steel, aluminum, titanium, carbon, conductive resin, etc., materials obtained by treating carbon or titanium on the surface of aluminum or stainless steel are used. In particular, aluminum or an aluminum alloy is preferable. The surface of these materials can be oxidized and used. Further, it is desirable to make the current collector surface uneven by surface treatment. As the shape, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a fiber group, a non-woven body shaped body, and the like are used in addition to the foil. The thickness is not particularly limited, but a thickness of 1 to 500 μm is used.
[0036]
In addition to a conductive agent and a binder, a filler, a dispersant, an ionic conductor, a pressure enhancer, and other various additives can be used for the electrode mixture. Any filler can be used as long as it is a fibrous material that does not cause a chemical change in the constructed battery. Usually, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. Although the addition amount of a filler is not specifically limited, 0 to 30 weight% is preferable with respect to an electrode mixture.
[0037]
In the configuration of the negative electrode plate and the positive electrode plate in the present invention, it is preferable that the negative electrode mixture surface is present at least on the opposite surface of the positive electrode mixture surface.
[0038]
The nonaqueous electrolyte used in the present invention is composed of a solvent and a lithium salt dissolved in the solvent. Non-aqueous solvents include, for example, cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, chain carbonates such as dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and dipropyl carbonate, methyl formate, and methyl acetate. Aliphatic carboxylic acid esters such as methyl propionate and ethyl propionate, γ-lactones such as γ-butyrolactone, chain ethers such as 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxyethane, etc. , Cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformamide, dioxolane, aceto Nitrile, propyl nitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, 3-methyl-2-oxazolidinone, propylene carbonate And aprotic organic solvents such as derivatives, tetrahydrofuran derivatives, ethyl ether, 1,3-propane sultone, anisole, dimethyl sulfoxide, N-methylpyrrolidone, and the like. use. Among these, a mixed system of a cyclic carbonate and a chain carbonate or a mixed system of a cyclic carbonate, a chain carbonate, and an aliphatic carboxylic acid ester is preferable.
[0039]
Examples of lithium salts that can be dissolved in these solvents include LiClO._Four, LiBF_Four, LiPF₆LiAlCl_Four, LiSbF₆, LiSCN, LiCl, LiCF_ThreeSO_Three, LiCF_ThreeCO₂, Li (CF_ThreeSO₂)₂, LiAsF₆, LiN (CF_ThreeSO₂)₂, LiB_TenCl_Ten, Lower aliphatic lithium carboxylate, LiCl, LiBr, LiI, lithium chloroborane, lithium tetraphenylborate, imides, etc., and these can be used singly or in combination of two or more. In particular, LiPF₆It is more preferable to include.
[0040]
A particularly preferred non-aqueous electrolyte in the present invention contains at least ethylene carbonate and ethyl methyl carbonate, and LiPF as a supporting salt.₆It is the electrolyte solution containing. The amount of the electrolyte added to the battery is not particularly limited, but a necessary amount can be used depending on the amount of the positive electrode material and the negative electrode material and the size of the battery. The amount of dissolution of the supporting electrolyte in the nonaqueous solvent is not particularly limited, but is preferably 0.2 to 2 mol / l. In particular, 0.5 to 1.5 mol / l is more preferable.
[0041]
In addition to the electrolytic solution, the following solid electrolyte can also be used. The solid electrolyte is classified into an inorganic solid electrolyte and an organic solid electrolyte. Well-known inorganic solid electrolytes include Li nitrides, halides, oxyacid salts, and the like. Among them, Li_FourSiO_Four, Li_FourSiO_Four-Lil-LiOH, xLi_ThreePO_Four-(1-x) Li_FourSiO_Four, Li₂SiS_Three, Li_ThreePO_Four-Li₂S-SiS₂In addition, phosphorus sulfide compounds are effective. For organic solid electrolytes, for example, polymer materials such as polyethylene oxide, polypropylene oxide, polyphosphazene, polyaziridine, polyethylene sulfide, polyvinyl alcohol, polyvinylidene fluoride, polyhexafluoropropylene, and derivatives, mixtures, and composites thereof are effective. is there.
[0042]
Furthermore, it is also effective to add other compounds to the electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, pyridine, hexaphosphoric acid triamide, nitrobenzene derivatives, crown ethers, quaternary ammonium salts, ethylene glycol dialkyl ether and the like can be mentioned.
[0043]
As the separator used in the present invention, an insulating microporous thin film having a large ion permeability and a predetermined mechanical strength is used. Moreover, it is preferable to have a function of closing the hole at a certain temperature or higher and increasing the resistance. Sheets, nonwoven fabrics or woven fabrics made from olefinic polymers such as polypropylene and polyethylene, glass fibers, or the like, which are resistant to organic solvents and hydrophobic, are used. The pore diameter of the separator is desirably in a range in which the positive and negative electrode materials, the binder, and the conductive agent detached from the electrode sheet do not permeate, for example, 0.01 to 1 μm is desirable. The thickness of the separator is generally 10 to 300 μm. The porosity is determined according to the permeability of the electrons and ions, the material, and the film pressure, but is generally preferably 30 to 80%.
[0044]
A polymer in which an organic electrolytic solution composed of a solvent and a lithium salt dissolved in the solvent is absorbed and held in a polymer material is included in the positive electrode mixture and the negative electrode mixture, and the organic electrolytic solution is absorbed and held. It is also possible to constitute a battery in which a porous separator made of is integrated with a positive electrode and a negative electrode. The polymer material is not particularly limited as long as it can absorb and retain the organic electrolyte solution, but a copolymer of vinylidene fluoride and hexafluoropropylene is particularly preferable.
[0045]
The shape of the battery can be applied to any of a coin type, a button type, a sheet type, a laminated type, a cylindrical type, a flat type, a square type, a large type used for an electric vehicle, and the like.
Further, the nonaqueous electrolyte secondary battery of the present invention can be used for a portable information terminal, a portable electronic device, a small electric power storage device for home use, a motorcycle, an electric vehicle, a hybrid electric vehicle, etc., but is not particularly limited thereto. I don't mean.
[0046]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
[0047]
In the following examples, a lithium-containing transition metal oxide a containing lithium as a main element constituting the spinel skeleton and manganese as a transition metal, and a group 2 magnesium and a group 13 aluminum at a molar ratio of 1: 2. Description will be made mainly on the system composed of the typical element oxide b having a spinel skeleton.
[0048]
<< Comparative Example 1 >>
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then the pellet was pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. The powder is again formed into pellets, and the pellets are fired at 800 ° C. for 12 hours in an atmosphere having an oxygen partial pressure of 1 atm (0.1 MPa) to produce manganese spinel (LiMn₂O_Four)
[0049]
A positive electrode mixture was prepared by mixing 80 parts by weight of this manganese spinel, 15 parts by weight of carbon black as a conductive agent, and 5 parts by weight of polytetrafluoroethylene as a binder.
A tripolar cell was produced using this positive electrode mixture. Lithium metal is used for the counter electrode and the reference electrode, and the electrolyte is propylene carbonate and lithium perchlorate (LiClO)._Four) Was dissolved at a concentration of 1 mol / L.
[0050]
The battery thus obtained was subjected to a charge / discharge test.
Charging / discharging is performed at a current density of 0.5 mA / cm.²And 30 cycles under conditions of a voltage range of 4.3 to 3.0 V and a temperature of 20 ° C. The discharge capacity at the first cycle was set as the initial capacity. Further, the discharge capacity at the 30th cycle when the discharge capacity at the 1st cycle was 100% was evaluated as the capacity retention rate. Table 1 shows the initial capacity and capacity retention rate.
[0051]
[Table 1]

[0052]
1 g of the obtained cubic manganese spinel was placed in 10 mL of electrolyte and stored at 60 ° C. for 10 days. Before and after storage, X-ray diffraction measurement and Rietveld analysis of manganese spinel were performed, and the change in the lattice constant was measured. Then, {(lattice constant after storage) − (lattice constant before storage)} ÷ (lattice constant before storage) × 100 (%) was defined as a lattice constant change rate. Table 2 shows the lattice constant change rate. Table 3 shows the measurement results of the lattice constant of manganese spinel before storage at 60 ° C.
[0053]
[Table 2]

[0054]
[Table 3]

[0055]
<< Comparative Example 2 >>
Synthesis was performed in the same manner as in Comparative Example 1 except that firing at 800 ° C. was performed in an atmosphere having an oxygen partial pressure of 0.9 atm. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the rate of change of the lattice constant by the same method as in Comparative Example 1.
[0056]
<< Comparative Example 3 >>
Synthesis was performed in the same manner as in Comparative Example 1 except that firing at 800 ° C. was performed in an atmosphere having an oxygen partial pressure of 0.8 atm. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the rate of change of the lattice constant by the same method as in Comparative Example 1.
[0057]
<< Comparative Example 4 >>
Synthesis was performed in the same manner as in Comparative Example 1 except that firing at 800 ° C. was performed in an atmosphere having an oxygen partial pressure of 0.7 atm. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the rate of change of the lattice constant by the same method as in Comparative Example 1.
[0058]
<< Comparative Example 5 >>
The same synthesis as in Comparative Example 1 was performed except that the baking at 800 ° C. was performed in the air. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0059]
<< Comparative Example 6 >>
Other than mixing basic magnesium carbonate so that the molar ratio of lithium and magnesium is 90:10, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 90:10. Were synthesized in the same manner as in Comparative Example 1. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the rate of change of the lattice constant by the same method as in Comparative Example 1.
[0060]
<< Comparative Example 7 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 93: 7, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 93: 7 Were synthesized in the same manner as in Comparative Example 1. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0061]
<< Comparative Example 8 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 95: 5, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 95: 5 Were synthesized in the same manner as in Comparative Example 1. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0062]
<< Comparative Example 9 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 98: 2, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 98: 2. Were synthesized in the same manner as in Comparative Example 1. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0063]
<< Comparative Example 10 >>
Other than mixing basic magnesium carbonate so that the molar ratio of lithium and magnesium is 90:10, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 90:10. Was synthesized in the same manner as in Comparative Example 4. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the rate of change of the lattice constant by the same method as in Comparative Example 1.
[0064]
<< Comparative Example 11 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 93: 7, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 93: 7 Was synthesized in the same manner as in Comparative Example 4. Table 1 shows the results of the charge / discharge test conducted in the same manner as in Comparative Example 1.
[0065]
<< Comparative Example 12 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 95: 5, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 95: 5 Was synthesized in the same manner as in Comparative Example 4. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0066]
<< Comparative Example 13 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 98: 2, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 98: 2. Was synthesized in the same manner as in Comparative Example 4. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0067]
<< Comparative Example 14 >>
Other than mixing the basic magnesium carbonate in the raw material mixture so that the molar ratio of lithium and magnesium is 90:10, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 90:10 Were synthesized in the same manner as in Comparative Example 5. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0068]
<< Comparative Example 15 >>
Other than mixing the basic magnesium carbonate so that the molar ratio of lithium and magnesium is 95: 5, and aluminum hydroxide so that the molar ratio of manganese and aluminum is 95: 5. Were synthesized in the same manner as in Comparative Example 5. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0069]
Example 1
Basic magnesium carbonate and aluminum hydroxide were weighed so that the molar ratio of magnesium to aluminum was 1: 2, mixed in an automatic mortar for 5 hours, and formed into pellets. The pellets were fired in air at 1400 ° C. for 5 hours, and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. The powder is again formed into pellets, and the pellets are fired in air at 1400 ° C. for 5 hours to form MgAl₂O_FourWas synthesized.
[0070]
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, mixed in an automatic mortar for 5 hours to form a pellet, and the pellet was calcined at 550 ° C. for 12 hours. .
MgAl so that the molar ratio of lithium to magnesium is 90:10.₂O_FourWas added and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed again into pellets, and the pellets were fired at 800 ° C. for 12 hours in an atmosphere with an oxygen partial pressure of 1.0 atm to obtain manganese spinel.
When the X-ray diffraction measurement of the obtained manganese spinel was performed, MgAl₂O_FourThe peak attributed to was not observed.
Table 1 shows the result of a charge / discharge test conducted in the same manner as in Comparative Example 1 using the obtained manganese spinel. Table 2 shows the results of measuring the lattice constant change rate by the same method as in Comparative Example 1. Table 3 shows the measurement results of the lattice constant of manganese spinel before storage at 60 ° C.
[0071]
Example 2
MgAl so that the molar ratio of lithium to magnesium is 95: 5₂O_FourThe same synthesis as in Example 1 was performed except that a raw material mixture containing was used. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0072]
Example 3
MgAl so that the molar ratio of lithium to magnesium is 98: 2.₂O_FourThe same synthesis as in Example 1 was performed except that a raw material mixture containing was used. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0073]
Example 4
Synthesis was performed in the same manner as in Example 1 except that baking at 800 ° C. was performed in an atmosphere having an oxygen partial pressure of 0.7 atm. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1. Table 2 shows the results of measuring the lattice constant change rate by the same method as in Comparative Example 1.
[0074]
Example 5
Synthesis was performed in the same manner as in Example 2 except that baking at 800 ° C. was performed in an atmosphere having an oxygen partial pressure of 0.7 atm. Table 1 shows the results of a charge / discharge test performed in the same manner as in Comparative Example 1.
[0075]
Example 6
In the same manner as in Example 1, MgAl₂O_FourWas synthesized.
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then the pellet was pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 11.5 hours in an atmosphere having an oxygen partial pressure of 1.0 atm.
MgAl so that the molar ratio of lithium to magnesium is 90:10 with respect to the fired product.₂O_FourWas added and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder mixture. This powder mixture was formed into pellets, and the pellets were fired at 800 ° C. for 0.5 hours in an atmosphere with an oxygen partial pressure of 1.0 atm to obtain manganese spinel.
When the X-ray diffraction measurement of the obtained manganese spinel was performed, MgAl₂O_FourA peak attributed to was observed.
Table 1 shows the result of a charge / discharge test conducted in the same manner as in Comparative Example 1 using the obtained manganese spinel. Table 3 shows the results obtained by performing X-ray diffraction measurement and Rietveld analysis and obtaining lattice constants.
[0076]
Example 7
In the same manner as in Example 1, MgAl₂O_FourWas synthesized.
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then the pellet was pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 9 hours in an atmosphere with an oxygen partial pressure of 1.0 atm.
MgAl so that the molar ratio of lithium to magnesium is 90:10 with respect to the fired product.₂O_FourWas added and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder mixture. This powder mixture was formed into pellets, and the pellets were fired at 800 ° C. for 3 hours in an atmosphere having an oxygen partial pressure of 1.0 atm to obtain manganese spinel.
When the X-ray diffraction measurement of the obtained manganese spinel was performed, MgAl₂O_FourA peak attributed to was observed.
Table 1 shows the result of a charge / discharge test conducted in the same manner as in Comparative Example 1 using the obtained manganese spinel. Table 3 shows the results obtained by performing X-ray diffraction measurement and Rietveld analysis and obtaining lattice constants.
[0077]
Example 8
In the same manner as in Example 1, MgAl₂O_FourWas synthesized.
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then the pellet was pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 6 hours in an atmosphere having an oxygen partial pressure of 1.0 atm.
MgAl so that the molar ratio of lithium to magnesium is 90:10 with respect to the fired product.₂O_FourWas added and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder mixture. This powder mixture was formed into pellets, and the pellets were fired at 800 ° C. for 6 hours in an atmosphere having an oxygen partial pressure of 1.0 atm to obtain manganese spinel.
When the X-ray diffraction measurement of the obtained manganese spinel was performed, MgAl₂O_FourThe peak attributed to was not observed.
Table 1 shows the result of a charge / discharge test conducted in the same manner as in Comparative Example 1 using the obtained manganese spinel. Table 3 shows the results obtained by performing X-ray diffraction measurement and Rietveld analysis and obtaining lattice constants.
[0078]
Example 9
In the same manner as in Example 1, MgAl₂O_FourWas synthesized.
Lithium carbonate and manganese dioxide were weighed so that the molar ratio of lithium to manganese was 1: 2, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then the pellet was pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 3 hours in an atmosphere having an oxygen partial pressure of 1.0 atm.
MgAl so that the molar ratio of lithium to magnesium is 90:10 with respect to the fired product.₂O_FourWas added and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder mixture. This powder mixture was formed into pellets, and the pellets were fired at 800 ° C. for 9 hours in an atmosphere having an oxygen partial pressure of 1.0 atm to obtain manganese spinel.
When the X-ray diffraction measurement of the obtained manganese spinel was performed, MgAl₂O_FourThe peak attributed to was not observed.
Table 1 shows the result of a charge / discharge test conducted in the same manner as in Comparative Example 1 using the obtained manganese spinel. Table 3 shows the results obtained by performing X-ray diffraction measurement and Rietveld analysis and obtaining lattice constants.
[0079]
From the results in Table 1, the following can be understood.
From Examples 1 to 5, MgAl was used as a raw material for manganese spinel.₂O_FourIncluding MgAl as a raw material for manganese spinel₂O_FourIt can be seen that the capacity retention rate is higher than when the raw material is included. This effect is due to the pre-synthesized MgAl₂O_FourIs dispersed in manganese spinel, the dispersed MgAl₂O_FourIs considered to be derived from the fact that it retains its crystal structure even though it is fine. That is, fine MgAl that stabilizes manganese spinel crystals₂O_FourIt is believed that the particles are efficiently dispersed in a manganese spinel matrix. On the other hand, MgAl is used as a raw material for manganese spinel.₂O_FourIf the raw material is included, the fine MgAl that stabilizes the manganese spinel crystals₂O_FourIt is considered that the formation of particles is not performed efficiently.
[0080]
Comparing Example 1 and Examples 6-9, the raw material of manganese spinel and MgAl₂O_FourIt can be seen that the longer the reaction time at 800 ° C., the smaller the initial capacity. Although the abundance of Li is the same for all samples, the capacity decreases with increasing reaction time because Mg and Al are LiMn.₂O_FourIt shows that Li which cannot be used tends to increase as it dissolves in the solution.
[0081]
Also, from Examples 6 to 9, the raw material of manganese spinel and MgAl₂O_FourIt can be seen that the longer the reaction time with, the lower the initial capacity, but the higher the capacity retention rate. In addition, even when the reaction time is relatively short, an excellent capacity retention rate can be obtained by using manganese spinel as a parent phase and MgAl dispersed in an island shape in the matrix.₂O_FourThe structure of the intermediate phase formed between and the fine MgAl that stabilizes the manganese spinel crystals₂O_FourThis is considered to have the same effect as particles. The existence of such an intermediate phase has been confirmed by micro X-ray diffraction measurement.
[0082]
From the results in Table 2, the following can be understood.
In Examples 1 and 4 in which the capacity retention rate is 95% or more, the lattice constant change rate is extremely small, whereas in Comparative Example 6 in which the capacity retention rate is 92% and Comparative Examples 1 to 4 and 10 in which the capacity retention rate is less than 90%, The lattice constant change rate shows a large value. This suggests that the comparative electrode material has a large structural change when stored at 60 ° C., and that the electrode materials of Examples 1 and 4 have almost no structural change. MgAl₂O_FourIt is considered that the cycle characteristics and the high-temperature storage characteristics are improved by uniformly dispersing the particles in the matrix and stabilizing the crystal structure of the electrode material through a common oxygen skeleton.
[0083]
The results of plotting the results in Table 3 are shown in FIG. On the horizontal axis, Li and Mn raw materials and MgAl₂O_FourAnd the reaction time at 800 ° C. is shown. The vertical axis represents the lattice constant of manganese spinel. Li and Mn raw materials and MgAl₂O_FourIn the sample obtained by reacting for 8 hours or more at 800 ° C., the lattice constant became constant.₂O_FourIs considered to have reacted completely and dissolved in manganese spinel.
That is, according to the present invention, MgAl which is another spinel component₂O_FourStarting material for MgAl₂O_FourMgAl because it is used₂O_FourCan be included in the manganese spinel in a highly dispersed state at the atomic level. Therefore, it is considered that a large number of Mg-O-Al bonds derived from another spinel component exist in the manganese spinel, and the crystal structure of the electrode material is greatly stabilized.
On the other hand, with the conventional technique, it is not possible to obtain a manganese spinel in which aluminum and magnesium are uniformly present at the atomic level. In other words, there is a region biased toward the replacement of manganese with aluminum and a region biased toward the replacement of lithium with magnesium.₂O_FourIs not included in manganese spinel in a highly dispersed state at the atomic level. Therefore, it is considered that there are few Mg—O—Al bonds derived from another spinel component in the manganese spinel, and the stabilization of the crystal structure of the electrode material becomes insufficient.
[0084]
Example 10
Basic magnesium carbonate and gallium oxide were weighed so that the molar ratio of magnesium to gallium was 1: 2, and these were mixed in an automatic mortar for 5 hours to form a pellet. The pellet was fired in air at 1400 ° C. for 5 hours, then pulverized in an automatic mortar for 5 hours, and formed into a pellet again. This pellet was calcined in air at 1400 ° C. for 5 hours, and MgGa₂O_FourWas synthesized. The MgGa thus obtained₂O_FourMgAl₂O_FourManganese spinel was obtained in the same manner as in Example 1 except that it was used instead of.
As a result of conducting a charge / discharge test in the same manner as in Comparative Example 1 using the obtained manganese spinel, the initial capacity was 93 mAh / g and the capacity retention rate was 97%.
From this result, MgAl₂O_FourIt can be seen that even when another spinel component other than the above is dispersed in the manganese spinel, the capacity retention rate is higher than in the case of the manganese spinel of Comparative Example 1 synthesized without dispersing another spinel component.
[0085]
Example 11
In the same manner as in Example 1, MgAl₂O_FourWas synthesized.
Lithium carbonate, chromium oxide, and manganese dioxide were weighed so that the molar ratio of lithium, chromium, and manganese was 1: 0.4: 1.6, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture Got. The raw material mixture was then formed into pellets and calcined at 550 ° C. for 12 hours.
MgAl so that the molar ratio of lithium to magnesium is 95: 5.₂O_FourWas added and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 12 hours in an atmosphere having an oxygen partial pressure of 1.0 atm to obtain a manganese spinel.
As a result of conducting a charge / discharge test in the same manner as in Comparative Example 1 except that the voltage range was 4.2 to 3.5 V, the initial capacity was 63 mAh / g, and the capacity retention rate was 98%.
[0086]
<< Comparative Example 16 >>
Lithium carbonate, chromium oxide, and manganese dioxide were weighed so that the molar ratio of lithium, chromium, and manganese was 1: 0.4: 1.6, and then mixed in an automatic mortar for 5 hours to obtain a raw material mixture Got. Next, the raw material mixture was formed into a pellet and calcined at 550 ° C. for 12 hours, and then pulverized and mixed in an automatic mortar for 5 hours to obtain a powder. This powder was again formed into a pellet, and the pellet was fired at 800 ° C. for 12 hours in an atmosphere having an oxygen partial pressure of 1.0 atm to obtain a manganese spinel.
As a result of conducting a charge / discharge test in the same manner as in Comparative Example 1 except that the voltage range was 4.2 to 3.5 V, the initial capacity was 70 mAh / g, and the capacity retention rate was 83%. From a comparison between Example 11 and Comparative Example 16, MgAl₂O_FourCompared to the manganese spinel of Comparative Example 16 synthesized without dispersing₂O_FourIt can be seen that the capacity retention rate is higher when the manganese spinel of Example 11 synthesized by dispersing is used. This suggests that when another spinel component is dispersed in manganese spinel having various compositions, the same capacity retention rate improving effect can be obtained in any manganese spinel having any composition.
[0087]
【The invention's effect】
As described above, according to the present invention, an electrode material excellent in high-temperature storage stability, cycle characteristics, and the like can be obtained. The nonaqueous electrolyte secondary battery using this electrode material has improved characteristics, particularly at high temperatures, as compared with the prior art.
[Brief description of the drawings]
FIG. 1 Li and Mn raw materials and MgAl₂O_FourIt is a figure which shows the relationship between the reaction time in 800 degreeC, and the lattice constant of manganese spinel.

Claims (11)

(1) a step of preparing a lithium-containing transition metal oxide a having a spinel crystal structure or a raw material thereof,
(2) A step of mixing lithium-containing transition metal oxide a or a raw material thereof with typical element oxide b that is electrochemically less active than lithium-containing transition metal oxide a.
(3) a step of firing the mixture obtained in step (2),
Have a, the typical element oxides b The production method of an electrode material which have a spinel-type crystal structure.   The electrode according to claim 1, wherein the typical element oxide b is an oxide containing at least one element selected from the group consisting of elements of Groups 2, 12, 13, 14, and 15 of the periodic table. Material manufacturing method. Typically element oxide b The production method of an electrode material according to claim 2, wherein the MgAl ₂ O _4.   The method for producing an electrode material according to claim 1, wherein the step (3) is a step of firing the mixture at 600 to 1000 ° C. The electrode material manufactured by the method in any one of Claims 1-4 . A phase A composed of a lithium-containing transition metal oxide a having a spinel type crystal structure and a phase B composed of a typical element oxide b electrochemically less active than the lithium-containing transition metal oxide a. will have a mesophase C comprising at least one of the constituent elements of the phases is dispersed in the a, phase a and phase B interface is phase a or phase with B, the typical element oxides b is, spinel The intermediate phase C is formed by interdiffusion of the constituent elements of the phase A and the constituent elements of the phase B at the interface between the phase A and the phase B. Electrode material. The electrode material according to claim 6, wherein the phase B and the intermediate phase C have an atomic arrangement common to at least one atomic arrangement of the constituent elements of the phase A. 7. The electrode according to claim 6 , wherein the typical element oxide b is an oxide containing at least one element selected from the group consisting of elements of Groups 2, 12, 13, 14, and 15 of the periodic table. material. The electrode material according to claim 8 , wherein the typical element oxide b is MgAl ₂ O ₄ . The electrode material according to claim 6 , wherein at least one of the constituent elements of the intermediate phase C has a concentration gradient from the phase A to the phase B in the intermediate phase C. A non-aqueous electrolyte, a nonaqueous electrolyte battery having an electrode material according to any one of claims 6-10.

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