JP2011065787A - Positive electrode and method of manufacturing the same - Google Patents

Positive electrode and method of manufacturing the same Download PDF

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JP2011065787A
JP2011065787A JP2009213664A JP2009213664A JP2011065787A JP 2011065787 A JP2011065787 A JP 2011065787A JP 2009213664 A JP2009213664 A JP 2009213664A JP 2009213664 A JP2009213664 A JP 2009213664A JP 2011065787 A JP2011065787 A JP 2011065787A
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positive electrode
active material
electrode active
material particles
matrix
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Ryoko Kanda
良子 神田
Yukihiro Ota
進啓 太田
Taku Kamimura
卓 上村
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Sumitomo Electric Industries Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode for producing a nonaqueous electrolyte battery with a high discharge capacity and excellent cycle characteristics. <P>SOLUTION: The positive electrode includes highly crystalline positive electrode active material particles and a matrix containing a low crystalline positive electrode active material filling gaps among the positive electrode active material particles. By using such a positive electrode for the nonaqueous electrolyte battery, the highly crystalline positive electrode active material particles can secure a sufficient discharge capacity. The positive electrode includes the highly crystalline positive electrode active material particles and the low crystalline matrix. A heterogeneous crystal structure of the positive electrode improves the cycle characteristics of the nonaqueous electrolyte battery. If the crystal structure of the positive electrode is heterogeneous, part of Li ions from the highly crystalline positive electrode active material particles disperses into a defective portion of the matrix, thereby a concentration difference of the Li ions in a thickness direction of a positive electrode active material layer during charge and discharge can be properly reduced within a range not lowering the discharge capacity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、非水電解質電池に利用される正極体、およびその製造方法に関するものである。特に、本発明は、放電容量が高く、繰り返しの充放電にも放電容量が低下し難い非水電解質電池とすることができる正極体、およびその製造方法に関するものである。   The present invention relates to a positive electrode body used for a nonaqueous electrolyte battery and a method for producing the same. In particular, the present invention relates to a positive electrode body that has a high discharge capacity and that is unlikely to have a low discharge capacity even during repeated charge and discharge, and a method for manufacturing the same.

携帯機器といった比較的小型の電気機器の電源に、正極集電体と正極活物質層を有する正極層、負極集電体と負極活物質層を有する負極層、および、これら電極層の間に配される電解質層を備える非水電解質電池が利用されている。非水電解質電池のなかでも特に、正・負極層間のＬｉイオンの移動により充放電を行うＬｉイオン電池は、小型でありながら高い放電容量を備える。   A power source of a relatively small electric device such as a portable device is provided with a positive electrode layer having a positive electrode current collector and a positive electrode active material layer, a negative electrode layer having a negative electrode current collector and a negative electrode active material layer, and a gap between these electrode layers. A non-aqueous electrolyte battery having an electrolyte layer is used. Among nonaqueous electrolyte batteries, in particular, a Li ion battery that charges and discharges by movement of Li ions between the positive and negative electrode layers has a high discharge capacity while being small.

近年、このような非水電解質電池の正極活物質層として、正極活物質を焼結した正極体を利用することが提案されている。例えば、特許文献１には、金属アルコキシドまたは金属水酸化物を原料として生成したゾルを、集電体となる基板上に塗工・焼成し、金属酸化物でできた焼結体からなる正極活物質層を形成することが開示されている。   In recent years, it has been proposed to use a positive electrode body obtained by sintering a positive electrode active material as a positive electrode active material layer of such a nonaqueous electrolyte battery. For example, Patent Document 1 discloses that a sol produced from a metal alkoxide or metal hydroxide as a raw material is coated and fired on a substrate serving as a current collector, and a positive electrode active comprising a sintered body made of the metal oxide. Forming a material layer is disclosed.

特開２００１−１４３６８８号公報JP 2001-143688 A

しかし、上記特許文献１の電池では、以下に示すような不具合があった。   However, the battery of Patent Document 1 has the following problems.

まず、一点目として、ゾル−ゲル法で形成した正極活物質層は低結晶性であるため、放電容量が小さくなるという問題が挙げられる。正極活物質層が低結晶性になるのは、ゾルを塗工する基板の耐熱性の問題から、焼結温度を高く設定することができないためである。ここで、結晶性の高低は、組成式から推定される結晶構造とは異なる構造となっている部分が多いか少ないか、即ち、結晶構造に原子の欠損などの欠陥が多いか少ないかを表すものである。つまり、低結晶性の正極活物質層は、微細で欠陥の多い結晶構造を有するものである。   First, since the positive electrode active material layer formed by the sol-gel method has low crystallinity, there is a problem that the discharge capacity becomes small. The reason why the positive electrode active material layer has low crystallinity is that the sintering temperature cannot be set high due to the heat resistance problem of the substrate to which the sol is applied. Here, the level of crystallinity indicates whether there are many or few portions having a structure different from the crystal structure estimated from the composition formula, that is, whether the crystal structure has many or few defects such as atomic defects. Is. That is, the low crystalline positive electrode active material layer has a fine and many crystal structure.

二点目として、充放電時のＬｉイオンの移動に伴い正極活物質層が膨張・収縮するため、充放電を繰り返すうちに、正極活物質層が破損する虞があるという問題を挙げることができる。正極活物質層が破損すると、電池の放電容量が大幅に低下してしまう。これは、ゾル−ゲル法で形成した正極活物質層の結晶構造がほぼ均質であり、充放電時の正極活物質層の膨張・収縮を緩和する部分が正極活物質層にないためであると推察される。   Secondly, since the positive electrode active material layer expands and contracts as Li ions move during charge / discharge, the positive electrode active material layer may be damaged during repeated charge / discharge. . When the positive electrode active material layer is damaged, the discharge capacity of the battery is significantly reduced. This is because the positive electrode active material layer formed by the sol-gel method has a substantially uniform crystal structure, and the positive electrode active material layer does not have a portion that relaxes expansion / contraction of the positive electrode active material layer during charge / discharge. Inferred.

三点目として、同文献の段落００２３に記載のように、１回のゾルの塗工で１０μｍを超える正極活物質層を形成すると、正極活物質層にひび割れなどが生じるという問題である。特に、近年では電池の高容量化を目的として正極活物質層を厚く形成したいというニーズがあるが、特許文献１の技術ではそのニーズに応える厚さの正極活物質層を１回のゾルの塗工で形成できなかった。そのような厚さの正極活物質層を形成しようとすれば、ゾルを塗工して焼結した正極活物質層の上に、さらにゾルを重ね塗りして焼結する必要がある。これでは、正極活物質層の形成が煩雑である上、重ね塗りした層間のＬｉイオン伝導性の低下が懸念される。   Thirdly, as described in paragraph 0023 of the same document, when a positive electrode active material layer having a thickness of more than 10 μm is formed by a single sol coating, there is a problem that a crack or the like is generated in the positive electrode active material layer. In particular, in recent years, there is a need to increase the thickness of the positive electrode active material layer for the purpose of increasing the capacity of the battery. However, in the technique of Patent Document 1, a positive electrode active material layer having a thickness corresponding to the need is applied once by applying a sol. It could not be formed by the work. If a positive electrode active material layer having such a thickness is to be formed, it is necessary to further coat and sinter the sol on the positive electrode active material layer coated and sintered. In this case, the formation of the positive electrode active material layer is complicated, and there is a concern that the Li ion conductivity decreases between the overcoated layers.

本発明は上記事情に鑑みてなされたものであり、その目的の一つは、放電容量が高く、繰り返しの充放電にも放電容量が低下し難い非水電解質電池を製造するための正極体を提供することにある。また、本発明の別の目的は、本発明正極体を容易に製造することができる正極体の製造方法を提供することにある。   The present invention has been made in view of the above circumstances, and one of its purposes is to provide a positive electrode body for producing a non-aqueous electrolyte battery that has a high discharge capacity and is difficult to reduce the discharge capacity even during repeated charge and discharge. It is to provide. Another object of the present invention is to provide a method for producing a positive electrode body that can easily produce the positive electrode body of the present invention.

（１）本発明正極体は、非水電解質電池に用いられる焼結体からなる正極体に係る。そして、本発明正極体は、高結晶性の正極活物質粒子と、前記正極活物質粒子の隙間を埋める低結晶性の正極活物質からなるマトリックスと、を備えることを特徴とする。 (1) This invention positive electrode body concerns on the positive electrode body which consists of a sintered compact used for a nonaqueous electrolyte battery. The positive electrode body of the present invention is characterized by comprising highly crystalline positive electrode active material particles and a matrix made of a low crystalline positive electrode active material that fills the gaps between the positive electrode active material particles.

ここで、既に説明したように、結晶性の高低は、結晶構造において、原子の欠損などの欠陥が多いか少ないかを表すものである。つまり、本発明正極体における低結晶性のマトリックスは、アモルファスではなく結晶構造を有するものの、高結晶性の正極活物質粒子よりも結晶構造に欠陥が多い。この結晶性の高低は、例えば、Ｘ線回折を行ったときの半値幅で判断することができる。   Here, as already described, the level of crystallinity represents whether the crystal structure has many or few defects such as atomic defects. That is, the low crystalline matrix in the positive electrode body of the present invention has a crystal structure rather than an amorphous structure, but has more defects in the crystal structure than the highly crystalline positive electrode active material particles. This level of crystallinity can be determined by, for example, the half width when X-ray diffraction is performed.

上記本発明正極体を正極層として利用した非水電解質電池は、高い放電容量と優れたサイクル特性を備えた電池となる。本発明正極体を用いた電池が高い放電容量を有する理由は、正極体に、高結晶性の正極活物質粒子を含有するためである。また、本発明正極体を用いた電池が優れたサイクル特性を有する理由は、正極体が、高結晶性の正極活物質粒子と低結晶性のマトリックスとからなる不均質な結晶構造を有するためと推察される。正極体の結晶構造が不均質であると、高結晶性の正極活物質粒子からのＬｉイオンの一部が、マトリックスの欠陥部分に分散するので、充放電時の正極活物質層の厚み方向におけるＬｉイオンの濃度差を、放電容量を低下させない範囲で適度に緩和することができるからである。   The nonaqueous electrolyte battery using the positive electrode body of the present invention as a positive electrode layer is a battery having a high discharge capacity and excellent cycle characteristics. The reason why the battery using the positive electrode body of the present invention has a high discharge capacity is that the positive electrode body contains highly crystalline positive electrode active material particles. In addition, the reason why the battery using the positive electrode body of the present invention has excellent cycle characteristics is that the positive electrode body has a heterogeneous crystal structure composed of high crystalline positive electrode active material particles and a low crystalline matrix. Inferred. If the crystal structure of the positive electrode body is inhomogeneous, a part of the Li ions from the highly crystalline positive electrode active material particles is dispersed in the defective portion of the matrix, and therefore in the thickness direction of the positive electrode active material layer during charge / discharge This is because the Li ion concentration difference can be moderated as long as the discharge capacity is not reduced.

（２）本発明正極体の一形態として、正極活物質粒子とマトリックスの組成はいずれも、ＬｉαＸβ(１−Ｘ)Ｏ２とすることができる。
αは、Ｃｏ，Ｎｉ，Ｍｎから選択される１種以上
βは、Ｆｅ，Ａｌから選択される１種以上
Ｘは、０．５以上、１．０以下 (2) As an embodiment of the positive electrode body of the present invention, the composition of the positive electrode active material particles and the matrix can be Liα X β (1-X) O 2 .
α is one or more selected from Co, Ni and Mn β is one or more selected from Fe and Al X is 0.5 or more and 1.0 or less

上記組成式で表される化合物の具体例を以下に列挙する。
ＬｉＣｏＯ２（α＝Ｃｏ、Ｘ＝１）
ＬｉＮｉＯ２（α＝Ｎｉ、Ｘ＝１）
ＬｉＭｎＯ２（α＝Ｍｎ、Ｘ＝１）
ＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２（α＝Ｃｏ＋Ｎｉ＋Ｍｎ、Ｘ＝１）
ＬｉＮｉ１／２Ｍｎ１／２Ｏ２（α＝Ｎｉ＋Ｍｎ、Ｘ＝１）
ＬｉＮｉ０．８Ｃｏ０．１５Ａｌ０．０５Ｏ２（α＝Ｃｏ＋Ｎｉ、β＝Ａｌ、Ｘ＝０．９５） Specific examples of the compound represented by the composition formula are listed below.
LiCoO 2 (α = Co, X = 1)
LiNiO 2 (α = Ni, X = 1)
LiMnO 2 (α = Mn, X = 1)
LiNi 1/3 Co 1/3 Mn 1/3 O 2 (α = Co + Ni + Mn, X = 1)
LiNi 1/2 Mn 1/2 O 2 (α = Ni + Mn, X = 1)
LiNi 0.8 Co 0.15 Al 0.05 O 2 (α = Co + Ni, β = Al, X = 0.95)

本発明正極体における正極活物質粒子とマトリックスは必ずしも同一組成である必要はないが、上記したような共通の組成式で表される化合物で両相を構成しても良い。例えば、正極活物質粒子をＬｉＣｏＯ２（α＝Ｃｏ、Ｘ＝１）とし、マトリックスを正極活物質粒子と同じＬｉＣｏＯ２とすることが挙げられる。但し、正極活物質粒子とマトリックスを同じＬｉＣｏＯ２とするにしても、両者の結晶性に差を設けておくことは言うまでも無い。その他、正極活物質粒子をＬｉＣｏＯ２とし、マトリックスをＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２（α＝Ｃｏ＋Ｎｉ＋Ｍｎ、Ｘ＝１）などとしても良い。このように、共通の組成式で表される正極活物質で正極活物質粒子とマトリックスを形成すると、当該粒子とマトリックスとの境界部分で原子の相互拡散が生じ易く、粒子とマトリックスとのなじみが良い。 The positive electrode active material particles and the matrix in the positive electrode body of the present invention do not necessarily have the same composition, but both phases may be composed of a compound represented by the common composition formula as described above. For example, the positive electrode active material particles may be LiCoO 2 (α = Co, X = 1), and the matrix may be the same LiCoO 2 as the positive electrode active material particles. However, it goes without saying that even if the positive electrode active material particles and the matrix are made of the same LiCoO 2 , there is a difference in crystallinity between the two. In addition, the positive electrode active material particles may be LiCoO 2 and the matrix may be LiNi 1/3 Co 1/3 Mn 1/3 O 2 (α = Co + Ni + Mn, X = 1). As described above, when the positive electrode active material particles and the matrix are formed of the positive electrode active materials represented by the common composition formula, interdiffusion of atoms easily occurs at the boundary between the particles and the matrix, and the familiarity between the particles and the matrix is increased. good.

（３）本発明正極体の一形態として、正極活物質粒子とマトリックスの合計体積に占める正極活物質粒子の体積の割合は、９０％以上であることが好ましい。 (3) As one form of this invention positive electrode body, it is preferable that the ratio of the volume of the positive electrode active material particle to the total volume of the positive electrode active material particle and the matrix is 90% or more.

上記構成によれば、正極体において、放電容量を高くすることに寄与する高結晶性の正極活物質粒子の量を十分に確保できる。   According to the said structure, in the positive electrode body, the quantity of the highly crystalline positive electrode active material particle which contributes to making discharge capacity high can be ensured enough.

（４）本発明正極体の一形態として、正極活物質粒子の平均結晶粒径は、５〜２０μｍであることが好ましい。 (4) As one form of this invention positive electrode body, it is preferable that the average crystal particle diameter of positive electrode active material particle is 5-20 micrometers.

上記構成によれば、各正極活物質粒子間の隙間に、適度な厚さのマトリックスを形成することができる。   According to the said structure, the matrix of moderate thickness can be formed in the clearance gap between each positive electrode active material particle.

（５）本発明正極体の製造方法は、非水電解質電池に利用される正極体の製造方法であって、以下の工程を備えることを特徴とする。
正極活物質の前駆物質を溶解した溶液を用意する工程。
高結晶性の正極活物質粒子を用意する工程。
前記溶液と前記正極活物質粒子とを混合する混合工程。
前記混合工程で得られた混合溶液を基板表面に塗工する塗工工程。
前記混合溶液を焼結する焼結工程。 (5) The manufacturing method of the positive electrode body of the present invention is a manufacturing method of a positive electrode body used for a nonaqueous electrolyte battery, and includes the following steps.
A step of preparing a solution in which a precursor of the positive electrode active material is dissolved.
A step of preparing highly crystalline positive electrode active material particles.
A mixing step of mixing the solution and the positive electrode active material particles.
A coating process for coating the mixed solution obtained in the mixing process on the substrate surface.
A sintering step of sintering the mixed solution;

本発明正極体の製造方法において用意する前駆物質は、溶液に溶解した段階で正極活物質となり始めるものであっても良いし、後述するように混合工程で加熱するか、あるいは焼結工程で焼結することで初めて正極活物質となるものであっても良い。前者の前駆物質を使用した方法は、いわゆる溶液法と呼ばれるものであり、後者の前駆物質を使用した方法は、いわゆるゾル−ゲル法と呼ばれるものである。また、塗工工程で用いる基板は、本発明正極体を非水電解質電池としたときに正極集電体となる金属板を利用することが好ましい。   The precursor prepared in the method for producing a positive electrode body of the present invention may begin to become a positive electrode active material when dissolved in a solution, or may be heated in a mixing process or sintered in a sintering process as described later. It may be a positive electrode active material for the first time by bonding. The former method using a precursor is a so-called solution method, and the latter method using a precursor is a so-called sol-gel method. Moreover, it is preferable that the board | substrate used at a coating process utilizes the metal plate used as a positive electrode electrical power collector, when this invention positive electrode body is made into a nonaqueous electrolyte battery.

本発明正極体の製造方法によれば、本発明正極体を製造することができる。特に、本発明正極体の製造方法によれば、塗工される混合溶液中に正極活物質粒子が含有され、混合溶液中の溶液成分が相対的に少なくなっているため、１回の塗工で厚い塗工膜を形成することができる。また、塗工膜中の溶液成分が少ないため、厚い塗工膜を形成しても、塗工膜を焼結して得られる正極体にひび割れなどが生じ難い。   According to the manufacturing method of the positive electrode body of the present invention, the positive electrode body of the present invention can be manufactured. In particular, according to the method for producing a positive electrode body of the present invention, since the positive electrode active material particles are contained in the mixed solution to be applied and the solution components in the mixed solution are relatively reduced, the coating solution is applied once. A thick coating film can be formed. Moreover, since there are few solution components in a coating film, even if a thick coating film is formed, it is hard to produce a crack etc. in the positive electrode body obtained by sintering a coating film.

（６）本発明正極体の製造方法の一形態として、焼結工程における焼結温度は、４５０〜６５０℃であることが好ましい。 (6) As one form of the manufacturing method of this invention positive electrode body, it is preferable that the sintering temperature in a sintering process is 450-650 degreeC.

焼結温度が４５０〜６５０℃であると、マトリックスの結晶性が低くなりすぎたり、あるいは高くなりすぎたりすることがなく、電池としたときに優れた充放電特性を発揮する正極体を製造することができる。   When the sintering temperature is 450 to 650 ° C., a positive electrode body that exhibits excellent charge / discharge characteristics when manufactured as a battery without the matrix crystallinity becoming too low or too high is produced. be able to.

（７）本発明正極体の製造方法の一形態として、混合工程は、焼結温度よりも低い温度で加熱しながら行なうことが好ましい。 (7) As one form of the manufacturing method of this invention positive electrode body, it is preferable to perform a mixing process, heating at temperature lower than sintering temperature.

上記構成のように、混合工程において加熱を行なうことで、溶液法であれば、正極活物質の生成を促進できるし、溶液の粘度を調節することで基板への混合溶液の塗工を容易にできる。また、ゾル−ゲル法であれば、混合の段階で正極活物質の生成を開始できるし、その生成量を調節することで基板への混合溶液の塗工を容易にできる。   As in the above configuration, by heating in the mixing step, if it is a solution method, the generation of the positive electrode active material can be promoted, and the viscosity of the solution can be adjusted to easily apply the mixed solution to the substrate. it can. Moreover, if it is a sol-gel method, the production | generation of a positive electrode active material can be started at the stage of mixing, and the application of the mixed solution to a board | substrate can be made easy by adjusting the production amount.

本発明正極体を用いて非水電解質電池を作製すれば、高い放電容量を有する電池とすることができる。また、この電池は、充放電を繰り返しても正極体に劣化が生じ難いため、初期の放電容量を長期にわたって維持することができる。   If a nonaqueous electrolyte battery is produced using the positive electrode body of the present invention, a battery having a high discharge capacity can be obtained. In addition, since this battery hardly deteriorates in the positive electrode body even after repeated charge and discharge, the initial discharge capacity can be maintained over a long period of time.

実施形態に係る非水電解質電池の概略構成図である。It is a schematic block diagram of the nonaqueous electrolyte battery which concerns on embodiment.

以下、図１を参照しつつ本発明の実施形態を説明する。なお、参照する図１に示す非水電解質電池１００は、あくまで本発明正極体を用いた非水電解質電池の一形態に過ぎない。   Hereinafter, an embodiment of the present invention will be described with reference to FIG. The nonaqueous electrolyte battery 100 shown in FIG. 1 to be referred to is merely one form of a nonaqueous electrolyte battery using the positive electrode body of the present invention.

［全体構成］
図１に示すように、非水電解質電池（Ｌｉイオン電池）１００は、正極層１と、負極層２と、これら電極層１，２の間に配される電解質層３とを有する。この電池１００は、正極層１と負極層２との間でＬｉイオンの遣り取りをすることで電池として機能する。そして、この電池１００の最も特徴とするところは、正極層１として、本発明正極体を用いたことにある。以下、電池１００に備わる正極体１について説明し、その後、電池１００に備わる他の構成について簡単に説明する。 [overall structure]
As shown in FIG. 1, the nonaqueous electrolyte battery (Li ion battery) 100 includes a positive electrode layer 1, a negative electrode layer 2, and an electrolyte layer 3 disposed between the electrode layers 1 and 2. The battery 100 functions as a battery by exchanging Li ions between the positive electrode layer 1 and the negative electrode layer 2. The most characteristic feature of the battery 100 is that the positive electrode body of the present invention is used as the positive electrode layer 1. Hereinafter, the positive electrode body 1 included in the battery 100 will be described, and then other configurations included in the battery 100 will be briefly described.

＜正極層＞
≪正極層の構成≫
正極層１は、集電機能を有する正極集電体１１と、その一面側に形成される正極活物質層１２と、を備える本発明正極体である。 <Positive electrode layer>
<Configuration of positive electrode layer>
The positive electrode layer 1 is a positive electrode body of the present invention including a positive electrode current collector 11 having a current collecting function and a positive electrode active material layer 12 formed on one side thereof.

正極層１（正極体）に備わる正極集電体１１としては、例えば、ＡｌやＣｕ、Ｎｉなどの単体金属や、ステンレスなどの合金を利用できる。   As the positive electrode current collector 11 provided in the positive electrode layer 1 (positive electrode body), for example, a single metal such as Al, Cu, or Ni, or an alloy such as stainless steel can be used.

一方、正極活物質層１２は、焼結体であって、高結晶性の正極活物質粒子と、各正極活物質粒子の隙間を埋める低結晶性の正極活物質からなるマトリックスと、を備える。このように、焼結体の結晶性を不均質にすることによって、電池１００の充放電時に正極活物質層１２の厚み方向におけるＬｉイオンの濃度差を緩和することができる。その結果、電池１００の充放電を繰り返しても、正極活物質層１２に割れや欠けなどの欠損が生じ難い電池１００、即ち、サイクル特性に優れた電池１００とすることができる。しかも、正極活物質層１２には高結晶性の正極活物質粒子が含有されているため、電池１００の放電容量を確保することができる。   On the other hand, the positive electrode active material layer 12 is a sintered body, and includes high crystalline positive electrode active material particles and a matrix made of a low crystalline positive electrode active material that fills the gaps between the positive electrode active material particles. As described above, by making the crystallinity of the sintered body inhomogeneous, the Li ion concentration difference in the thickness direction of the positive electrode active material layer 12 can be reduced during charging and discharging of the battery 100. As a result, even when charging / discharging of the battery 100 is repeated, it is possible to obtain a battery 100 in which the positive electrode active material layer 12 is less likely to be broken or chipped, that is, a battery 100 having excellent cycle characteristics. Moreover, since the positive electrode active material layer 12 contains highly crystalline positive electrode active material particles, the discharge capacity of the battery 100 can be ensured.

正極活物質粒子とマトリックスは、正極活物質であれば特に限定されない。例えば、正極活物質として、ＬｉαＸβ(１−Ｘ)Ｏ２（αはＣｏ，Ｎｉ，Ｍｎから選択される１種以上、βはＦｅ，Ａｌから選択される１種以上、Ｘは０．５以上、１．０以下）を用いることが好ましい。具体的には、正極活物質として、ＬｉＣｏＯ２やＬｉＮｉＯ２、ＬｉＭｎＯ２、ＬｉＣｏ０.５Ｆｅ０.５Ｏ２、ＬｉＣｏ１／２Ａｌ１／２Ｏ２などを利用できる。また、正極活物質粒子とマトリックスは、同一の組成であっても良いし、異なる組成であっても良い。同一組成であれば、粒子とマトリックスとの境界部分で原子の相互拡散が生じ易く、粒子とマトリックスとのなじみが良い。そのため、このような正極活物質層１２を利用すれば、放電容量が高く、サイクル特性に優れた非水電解質電池１００とすることができる。 The positive electrode active material particles and the matrix are not particularly limited as long as they are positive electrode active materials. For example, as the positive electrode active material, Liα X β (1-X) O 2 (α is one or more selected from Co, Ni, and Mn, β is one or more selected from Fe and Al, and X is 0. It is preferable to use 5 or more and 1.0 or less. Specifically, LiCoO 2 , LiNiO 2 , LiMnO 2 , LiCo 0.5 Fe 0.5 O 2 , LiCo 1/2 Al 1/2 O 2, etc. can be used as the positive electrode active material. Further, the positive electrode active material particles and the matrix may have the same composition or different compositions. If the composition is the same, atomic interdiffusion is likely to occur at the boundary between the particle and the matrix, and the familiarity between the particle and the matrix is good. Therefore, if such a positive electrode active material layer 12 is used, the nonaqueous electrolyte battery 100 having a high discharge capacity and excellent cycle characteristics can be obtained.

また、正極活物質粒子とマトリックスの結晶性は、例えば、ＸＲＤ（Ｘ−ｒａｙ ｄｉｆｆｒａｃｔｉｏｎ）の回折ピークの半値幅により特定することができる。測定する物質の結晶構造に欠陥が多いほど、即ち、測定する物質の結晶性が低いほど、半値幅はブロードになる傾向があるからである。ここで、正極活物質層１２における結晶性の高低は、あくまで、正極活物質粒子とマトリックスとを比較したときの相対的な高低であって、当該粒子とマトリックスとが実質的に同一と見なせるような結晶性でなければ良い。正極活物質粒子とマトリックスのそれぞれの結晶性について定量的に規定すると、例えば、正極活物質粒子をＸＲＤ法で評価した結果、例えば、（００３）面の半値幅Ｗ１で規定するのであれば、０．１０≦Ｗ１≦０．３０であることが好ましく、（１０４）面の半値幅Ｗ２で規定するのであれば、０．１０≦Ｗ２≦０．２７であることが好ましい。また、マトリックスを同様にＸＲＤ法で評価した結果、（００３）面の半値幅Ｗ１で規定するのであれば、０．３５≦Ｗ１≦０．６６とすることが好ましく、（１０４）面の半値幅Ｗ２で規定するのであれば、０．２９≦Ｗ２≦０．４０であることが好ましい。正極活物質粒子の結晶性が高いほど、電池の放電容量を向上させることができる。一方、マトリックスの結晶性が低すぎると、マトリックスを設けた効果が低くなる虞がある。   The crystallinity of the positive electrode active material particles and the matrix can be specified by, for example, the half width of the diffraction peak of XRD (X-ray diffraction). This is because the half-value width tends to become broader as the crystal structure of the substance to be measured has more defects, that is, the crystallinity of the substance to be measured is lower. Here, the level of crystallinity in the positive electrode active material layer 12 is a relative level when the positive electrode active material particles and the matrix are compared, and the particles and the matrix can be regarded as substantially the same. If it is not very crystalline When the crystallinity of each of the positive electrode active material particles and the matrix is quantitatively defined, for example, when the positive electrode active material particles are evaluated by the XRD method, for example, if defined by the half width W1 of the (003) plane, 0 .10 ≦ W1 ≦ 0.30, preferably 0.10 ≦ W2 ≦ 0.27 if defined by the half width W2 of the (104) plane. Similarly, when the matrix is similarly evaluated by the XRD method, if it is defined by the half width W1 of the (003) plane, it is preferable to satisfy 0.35 ≦ W1 ≦ 0.66, and the half width of the (104) plane If it is defined by W2, it is preferable that 0.29 ≦ W2 ≦ 0.40. The higher the crystallinity of the positive electrode active material particles, the more the discharge capacity of the battery can be improved. On the other hand, if the crystallinity of the matrix is too low, the effect of providing the matrix may be reduced.

また、正極活物質粒子とマトリックスの合計体積に占める正極活物質粒子の体積割合は、９０％以上であることが好ましい。このような体積割合であれば、電池１００の放電容量を向上させることができるし、サイクル特性も向上させることができる。マトリックスが少なすぎると、マトリックスを設けた効果が損なわれるため、上記体積割合の上限は、９５％以下である。   The volume ratio of the positive electrode active material particles to the total volume of the positive electrode active material particles and the matrix is preferably 90% or more. With such a volume ratio, the discharge capacity of the battery 100 can be improved, and the cycle characteristics can also be improved. If the matrix is too small, the effect of providing the matrix is impaired, so the upper limit of the volume ratio is 95% or less.

その他、正極活物質粒子の平均結晶粒径は、５〜２０μｍとすることが好ましい。このような平均結晶粒径の正極活物質粒子を利用すれば、当該粒子間のマトリックスの厚さを適度な厚さとすることができる。その結果、電池１００の放電容量とサイクル特性を向上させることができる。より好ましい平均結晶粒径は、８〜１２μｍである。   In addition, the average crystal grain size of the positive electrode active material particles is preferably 5 to 20 μm. If positive electrode active material particles having such an average crystal grain size are used, the thickness of the matrix between the particles can be set to an appropriate thickness. As a result, the discharge capacity and cycle characteristics of the battery 100 can be improved. A more preferable average crystal grain size is 8 to 12 μm.

≪正極層の製造方法≫
上述した正極層１（正極体）を製造するには、大きく分けて溶液法とゾル−ゲル法を用いることができる。いずれの方法も、以下の５工程を有する点で共通する。
正極活物質の前駆物質を溶解した溶液を用意する工程。
高結晶性の正極活物質粒子を用意する工程。
前記溶液と前記正極活物質粒子とを混合する混合工程。
前記混合工程で得られた混合溶液を基板表面に塗工する塗工工程。
前記混合溶液を焼結する焼結工程。 ≪Method for manufacturing positive electrode layer≫
In order to manufacture the positive electrode layer 1 (positive electrode body) described above, a solution method and a sol-gel method can be roughly used. Both methods are common in that they have the following five steps.
A step of preparing a solution in which a precursor of the positive electrode active material is dissolved.
A step of preparing highly crystalline positive electrode active material particles.
A mixing step of mixing the solution and the positive electrode active material particles.
A coating process for coating the mixed solution obtained in the mixing process on the substrate surface.
A sintering step of sintering the mixed solution;

（溶液法）
まず、正極活物質の前駆物質を溶解した溶液を用意する。溶液法では、溶液を作製した時点で前駆物質が正極活物質になり始める。例えば、作製する正極活物質がＬｉＣｏＯ２であれば、前駆物質として酢酸リチウムや酢酸コバルトを挙げることができ、これら前駆物質を溶媒に溶かした時点でＬｉＣｏＯ２が生成し始める。 (Solution method)
First, a solution in which a precursor of the positive electrode active material is dissolved is prepared. In the solution method, the precursor starts to become a positive electrode active material when the solution is prepared. For example, if the positive electrode active material to be produced is LiCoO 2 , examples of the precursor include lithium acetate and cobalt acetate, and LiCoO 2 starts to be generated when these precursors are dissolved in a solvent.

次に、高結晶性の正極活物質粒子を用意する。このような正極活物質粒子は、市販品であっても良いし、正極活物質の焼結体を作製して、その焼結体を粉砕するなどして得たものであっても良い。市販されている正極活物質粒子は概ね、本明細書中に規定する高結晶性の正極活物質粒子である。この正極活物質粒子の平均粒径は、作製する正極体における粒子の平均粒径と同じものとすれば良い。その理由は、後工程の焼結工程における温度が低いため、正極活物質粒子の粒成長が殆ど生じないからである。   Next, highly crystalline positive electrode active material particles are prepared. Such positive electrode active material particles may be commercially available, or may be obtained by preparing a sintered body of the positive electrode active material and pulverizing the sintered body. Commercially available cathode active material particles are generally highly crystalline cathode active material particles as defined herein. The average particle diameter of the positive electrode active material particles may be the same as the average particle diameter of the particles in the positive electrode body to be produced. The reason is that almost no grain growth of the positive electrode active material particles occurs because the temperature in the subsequent sintering process is low.

上述のようにして用意した前駆物質を溶解した溶液と、正極活物質粉末とを混合して混合溶液を作製し、その混合溶液を正極集電体１１となる基板に塗工する。ここで、混合溶液の作製は加熱しながら行なっても良く、その場合、前駆物質の正極活物質への変化を促進できる。また、加熱により溶液の粘度を調節でき、その結果として、基板への混合溶液の塗工を容易にできる。加熱温度は、溶液の溶媒の種類や、前駆物質の種類などによって適宜選択すれば良いが、概ね４０〜１００℃とすると良い。   The solution prepared by dissolving the precursor prepared as described above and the positive electrode active material powder are mixed to prepare a mixed solution, and the mixed solution is applied to the substrate to be the positive electrode current collector 11. Here, the preparation of the mixed solution may be performed while heating, in which case the change of the precursor to the positive electrode active material can be promoted. Further, the viscosity of the solution can be adjusted by heating, and as a result, the mixed solution can be easily applied to the substrate. The heating temperature may be appropriately selected depending on the type of solvent in the solution, the type of precursor, and the like, but it is preferably about 40 to 100 ° C.

最後に、混合溶液を塗工した基板を焼結することで、正極活物質粒子同士の隙間に、前駆物質を起源とする正極活物質のマトリックスが形成された本発明正極体を完成する。焼結工程は、乾燥→仮焼成→本焼成というように段階を踏むことが好ましい。各段階の好ましい範囲は、以下の通りである。
乾燥 ：９０〜１５０℃×３０〜３００ｍｉｎ
仮焼成：３００〜４００℃×１０〜３００ｍｉｎ
本焼成：４５０〜６５０℃×１０〜３００ｍｉｎ Finally, the substrate coated with the mixed solution is sintered to complete the positive electrode body of the present invention in which a matrix of the positive electrode active material originating from the precursor is formed in the gap between the positive electrode active material particles. The sintering process preferably takes steps such as drying → pre-firing → main firing. Preferred ranges for each stage are as follows.
Drying: 90-150 ° C x 30-300 min
Temporary firing: 300-400 ° C. × 10-300 min
Main firing: 450-650 ° C. × 10-300 min

ここで、本焼成の温度を４５０℃未満とすると、マトリックスの結晶性が低くなりすぎたり、マトリックスが低温相（スピネル構造）となったりする虞がある。一方、焼結温度を６５０℃超とすると、マトリックスの結晶性が高くなりすぎる虞がある。   Here, if the temperature of the main baking is less than 450 ° C., the crystallinity of the matrix may be too low, or the matrix may become a low temperature phase (spinel structure). On the other hand, if the sintering temperature exceeds 650 ° C., the crystallinity of the matrix may be too high.

（ゾル−ゲル法）
ゾル−ゲル法では、溶液法とは用意する前駆物質が異なる。以下、溶液法との相違点を中心に説明する。 (Sol-gel method)
In the sol-gel method, the prepared precursor is different from the solution method. Hereinafter, the difference from the solution method will be mainly described.

ゾル−ゲル法で使用する前駆物質は、加熱に伴い加水分解・縮重合することで正極活物質となる金属アルコキシドである。つまり、ゾル−ゲル法における前駆物質は、溶媒に溶解させた時点では反応せず、熱を加えることによって始めて正極活物質となるものである。   The precursor used in the sol-gel method is a metal alkoxide that becomes a positive electrode active material by hydrolysis and polycondensation with heating. That is, the precursor in the sol-gel method does not react when dissolved in the solvent, and becomes a positive electrode active material only by applying heat.

金属アルコキシドを前駆物質とする場合も焼結工程は、溶液法と同じ条件とすることができる。即ち、乾燥→仮焼成→本焼成というように段階を踏んで行うことが好ましい。   Even when a metal alkoxide is used as a precursor, the sintering process can be performed under the same conditions as in the solution method. That is, it is preferable to carry out steps such as drying → pre-firing → main firing.

以上の工程を備えるゾルーゲル法によっても、高結晶性の正極活物質粒子の隙間に低結晶性のマトリックスを形成した本発明正極体を作製することができる。   The positive electrode body of the present invention in which a low crystalline matrix is formed in the gaps between the highly crystalline positive electrode active material particles can also be produced by the sol-gel method including the above steps.

＜負極層＞
図１の負極層２は、集電体を兼ねる負極活物質層からなる。もちろん、負極層２は、負極集電体を別個に備えていても良い。この負極層２に含まれる負極活物質としては、金属Ｌｉなどを挙げることができる。その他、負極活物質としては、ＳｉやＣのようにＬｉと化合物を形成することができる元素や、Ｎｂ２Ｏ５などのＬｉと化合物を形成することができる化合物を利用することができる。 <Negative electrode layer>
The negative electrode layer 2 in FIG. 1 is composed of a negative electrode active material layer that also serves as a current collector. Of course, the negative electrode layer 2 may include a negative electrode current collector separately. Examples of the negative electrode active material contained in the negative electrode layer 2 include metal Li. In addition, as the negative electrode active material, an element that can form a compound with Li, such as Si or C, or a compound that can form a compound with Li, such as Nb 2 O 5, can be used.

＜電解質層＞
電解質層３は、正極層１と負極層２との間のＬｉイオンの遣り取りを媒介する層である。電解質層３に要求される特性は、低電子伝導性で、高Ｌｉイオン伝導性であることである。この電解質層３は、液体であっても固体であっても良い。例えば、前者の場合、正極層１と負極層２との間を絶縁するセパレータと、高Ｌｉイオン伝導性の有機電解液とで電解質層３を構成することができる。一方、後者の場合、低電子伝導性で高Ｌｉイオン伝導性の固体状の硫化物や酸化物で電解質層３を構成することができる。硫化物としては、Ｌｉ２Ｓ−Ｐ２Ｓ５など、酸化物としては、ＬｉＰＯＮなどを挙げることができる。 <Electrolyte layer>
The electrolyte layer 3 is a layer that mediates exchange of Li ions between the positive electrode layer 1 and the negative electrode layer 2. The characteristics required for the electrolyte layer 3 are low electron conductivity and high Li ion conductivity. The electrolyte layer 3 may be a liquid or a solid. For example, in the former case, the electrolyte layer 3 can be composed of a separator that insulates between the positive electrode layer 1 and the negative electrode layer 2 and a high Li ion conductive organic electrolyte. On the other hand, in the latter case, the electrolyte layer 3 can be composed of a solid sulfide or oxide having low electron conductivity and high Li ion conductivity. Examples of the sulfide include Li 2 S—P 2 S 5 , and examples of the oxide include LiPON.

＜緩衝層＞
非水電解質電池１００は、正極層１、負極層２、電解質層３を基本とするが、正極層１と電解質層３との間に緩衝層４を備えていても良い。緩衝層４は、電解質層３に固体状の硫化物を用いた場合に必要となるものであり、正極層１と電解質層３との界面近傍におけるＬｉイオンの偏りを緩和するためのものである。当該界面近傍においてＬｉイオンの偏りが生じると、その偏りに起因して電解質層３の正極層１側の領域においてＬｉイオンが欠乏した空乏層が形成され、電池１００の放電容量を低下させる。そのため、緩衝層４を設けて、緩衝層４で当該界面でのＬｉイオンの偏りを緩和することで、充放電に伴う電池１００の放電容量の低下を抑制できる。このような緩衝層４の材料としては、例えば、ＬｉＮｂＯ３や、ＬｉＴａＯ３などを利用することができる。 <Buffer layer>
The nonaqueous electrolyte battery 100 basically includes a positive electrode layer 1, a negative electrode layer 2, and an electrolyte layer 3, but a buffer layer 4 may be provided between the positive electrode layer 1 and the electrolyte layer 3. The buffer layer 4 is necessary when a solid sulfide is used for the electrolyte layer 3, and is for reducing the bias of Li ions near the interface between the positive electrode layer 1 and the electrolyte layer 3. . When Li ions are biased in the vicinity of the interface, a depletion layer lacking Li ions is formed in the region on the positive electrode layer 1 side of the electrolyte layer 3 due to the bias, and the discharge capacity of the battery 100 is reduced. Therefore, by providing the buffer layer 4 and relaxing the unevenness of Li ions at the interface by the buffer layer 4, it is possible to suppress a decrease in the discharge capacity of the battery 100 due to charge / discharge. For example, LiNbO 3 or LiTaO 3 can be used as the material of the buffer layer 4.

図１に示す非水電解質電池１００を実際に作製し、そのサイクル特性を評価した。また、本発明とは異なる構造を有する正極体を利用した比較例の非水電解質電池を作製し、同様にサイクル特性を評価した。   The nonaqueous electrolyte battery 100 shown in FIG. 1 was actually produced and its cycle characteristics were evaluated. Further, a non-aqueous electrolyte battery of a comparative example using a positive electrode body having a structure different from that of the present invention was produced, and the cycle characteristics were similarly evaluated.

［実施例１の非水電解質電池］
＜作製手順＞
まず、電池１００の作製にあたり、直径１６ｍｍのＳＵＳ基板を用意した。このＳＵＳ基板は、電池１００の正極集電体１１を構成するものである。 [Nonaqueous Electrolyte Battery of Example 1]
<Production procedure>
First, in manufacturing the battery 100, a SUS substrate having a diameter of 16 mm was prepared. This SUS substrate constitutes the positive electrode current collector 11 of the battery 100.

また、イソプロパノール（ｉ−Ｃ３Ｈ７ＯＨ）と酢酸との混合液に、ポリビニルピロリドンと酢酸リチウム（ＣＨ３ＣＯＯＬｉ）を溶解させた混合液Ａを作製すると共に、水に酢酸コバルト（Ｃｏ(Ｃ２Ｈ３Ｏ２)２・４Ｈ２Ｏ）を溶解させた混合液Ｂを作製した。そして、混合液Ａと混合液Ｂとを混合した混合液Ｃに、平均結晶粒径１０μｍのＬｉＣｏＯ２粉末（正極活物質粉末）を投入して、８０℃×４ｈ、スターラーを用いて混合した。 Further, in a mixture of isopropanol (i-C 3 H 7 OH ) and acetic acid, as well as prepare a mixed liquid A prepared by dissolving polyvinyl pyrrolidone and lithium acetate (CH 3 COOLi), water cobalt acetate (Co (C 2 H 3 O 2 ) 2 · 4H 2 O) was prepared. Then, LiCoO 2 powder (positive electrode active material powder) having an average crystal grain size of 10 μm was added to the mixed liquid C obtained by mixing the mixed liquid A and the mixed liquid B, and mixed using a stirrer at 80 ° C. for 4 hours.

次に、用意したＳＵＳ基板の一面に、上記混合液Ｃ（正極活物質粉末を含む）をスキージで塗布し、液成分を蒸発させて、直径１６ｍｍ×厚さ２０μｍの塗工膜を形成した。そして、塗工膜を備えるＳＵＳ基板を焼結炉に導入し、１００℃×２ｈの乾燥、３００℃×３ｈの仮焼成、５００℃×３ｈの本焼成を経て正極活物質層１２を作製した。   Next, the mixed liquid C (including the positive electrode active material powder) was applied to one surface of the prepared SUS substrate with a squeegee to evaporate the liquid component, thereby forming a coating film having a diameter of 16 mm and a thickness of 20 μm. And the SUS board | substrate provided with a coating film was introduce | transduced into the sintering furnace, and the positive electrode active material layer 12 was produced through 100 degreeC x 2 h drying, 300 degreeC x 3 h temporary baking, and 500 degreeC x 3 h main baking.

作製した正極活物質層１２の断面をＳＥＭで観察したところ、正極活物質粒子の隙間に微細な結晶構造を有するマトリックスが形成されていた。また、ＳＥＭ写真における粒子とマトリックスとの面積割合を測定したところ、粒子が９０％以上を占めていた。この面積割合は、正極活物質層１２に占める粒子の体積割合と見なすことができる。さらに、正極活物質粒子とマトリックスをＸＲＤ法で測定したところ、粒子とマトリックスは同じ組成を有するものの、マトリックスの回折ピークの半値幅（（００３）面の半値幅＝０．５０、（１０４）面の半値幅＝０．３８）は、粒子の回折ピークの半値幅（（００３）面の半値幅＝０．２７、（１０４）面の半値幅＝０．２５）よりもブロードであった。半値幅がブロードであるということは、結晶構造に欠陥があり、結晶性が低いことを意味するので、粒子の方がマトリックスよりも高結晶性であることがわかる。   When the cross section of the produced positive electrode active material layer 12 was observed with an SEM, a matrix having a fine crystal structure was formed in the gaps between the positive electrode active material particles. Moreover, when the area ratio of the particle | grains and matrix in a SEM photograph was measured, particle | grains occupied 90% or more. This area ratio can be regarded as the volume ratio of the particles in the positive electrode active material layer 12. Furthermore, when the positive electrode active material particles and the matrix were measured by the XRD method, the particles and the matrix had the same composition, but the half width of the diffraction peak of the matrix (the half width of the (003) plane = 0.50, the (104) plane The half-value width of 0.38) was broader than the half-value width of the diffraction peak of the particles (half-value width of (003) plane = 0.27, half-value width of (104) plane = 0.25). The fact that the half width is broad means that there is a defect in the crystal structure and the crystallinity is low, so that it is understood that the particles are higher in crystallinity than the matrix.

次に、正極活物質層１２の上にエキシマレーザーアブレーション法により緩衝層４を形成した。緩衝層４は、ＬｉＮｂＯ３からなり、直径１６ｍｍ×平均厚さ２０ｎｍであった。この緩衝層４は、既に述べたように、正極活物質層１２と後述する硫化物系の電解質層３との境界近傍でＬｉイオンの偏りを緩衝するためのものである。 Next, the buffer layer 4 was formed on the positive electrode active material layer 12 by excimer laser ablation. The buffer layer 4 was made of LiNbO 3 and had a diameter of 16 mm × an average thickness of 20 nm. As described above, the buffer layer 4 is for buffering the deviation of Li ions in the vicinity of the boundary between the positive electrode active material layer 12 and a sulfide-based electrolyte layer 3 described later.

次に、緩衝層４の上にエキシマレーザーアブレーション法により固体の電解質層３を形成した。電解質層３は、Ｌｉ２Ｓ−Ｐ２Ｓ５からなり、直径１６ｍｍ×平均厚さは１０μｍであった。 Next, the solid electrolyte layer 3 was formed on the buffer layer 4 by excimer laser ablation. The electrolyte layer 3 was made of Li 2 S—P 2 S 5 and had a diameter of 16 mm × an average thickness of 10 μm.

電解質層３の形成が終了したら、次に負極層２の形成を行う。まず、電解質層３の中心部分が直径１０ｍｍの大きさで露出するように電解質層３の上にマスクを施し、この露出した部分に真空蒸着法を用いて厚さ１μｍの金属Ｌｉからなる負極層２を形成した。この負極層２は、負極集電体を兼ねる。   When the formation of the electrolyte layer 3 is completed, the negative electrode layer 2 is then formed. First, a mask is applied on the electrolyte layer 3 so that the central portion of the electrolyte layer 3 is exposed with a diameter of 10 mm, and a negative electrode layer made of metal Li having a thickness of 1 μm is applied to the exposed portion using a vacuum deposition method. 2 was formed. The negative electrode layer 2 also serves as a negative electrode current collector.

最後に、負極層２の形成が終了した積層体をアルミラミネートパックに封止して、正極集電体１１と負極層２（集電体を兼ねる）からタブリードを引き出して電池１００を完成した。   Finally, the laminate after the formation of the negative electrode layer 2 was sealed in an aluminum laminate pack, and tab leads were drawn from the positive electrode current collector 11 and the negative electrode layer 2 (also serving as a current collector) to complete the battery 100.

［実施例２の非水電解質電池］
本焼成の温度を４５０℃とした点以外は、実施例１と同じ製造方法により正極体を作製し、その正極体を使用して非水電解質電池（実施例２）を作製した。つまり、この実施例２の正極体は、実施例１の正極体よりも低い温度で焼結されたものである。そのため、実施例２の正極体に備わるマトリックスの結晶性は、実施例１の正極体よりもさらに低くなる。具体的なマトリックスの（００３）面の半値幅は０．６６、（１０４）面の半値幅は０．４０であった。また、正極活物質粒子の半値幅は実施例１と同じであった。 [Nonaqueous Electrolyte Battery of Example 2]
A positive electrode body was produced by the same manufacturing method as in Example 1 except that the temperature for main firing was 450 ° C., and a nonaqueous electrolyte battery (Example 2) was produced using the positive electrode body. That is, the positive electrode body of Example 2 was sintered at a lower temperature than the positive electrode body of Example 1. Therefore, the crystallinity of the matrix provided in the positive electrode body of Example 2 is further lower than that of the positive electrode body of Example 1. In the specific matrix, the half width of the (003) plane was 0.66, and the half width of the (104) plane was 0.40. Further, the half width of the positive electrode active material particles was the same as that in Example 1.

［比較例１の非水電解質電池］
本焼成の温度を８００℃とした点以外は、実施例１と同じ製造方法により焼結体を作製し、その正極体を使用して非水電解質電池（比較例１）を作製した。つまり、この比較例１の正極体は、実施例１の正極体よりも高い温度で焼結されたものである。そのため、比較例１の正極体に備わるマトリックスの結晶性は、実施例１よりも高くなる。具体的なマトリックスの（００３）面の半値幅は０．３０、（１０４）面の半値幅は０．２７であり、正極活物質粒子の半値幅とほぼ同じであった。つまり、比較例１の正極体は、正極活物質粒子もマトリックスも実質的に均質な結晶性を有する正極体であると言える。 [Nonaqueous Electrolyte Battery of Comparative Example 1]
A sintered body was produced by the same manufacturing method as in Example 1 except that the temperature of the main firing was 800 ° C., and a nonaqueous electrolyte battery (Comparative Example 1) was produced using the positive electrode body. That is, the positive electrode body of Comparative Example 1 was sintered at a higher temperature than the positive electrode body of Example 1. Therefore, the crystallinity of the matrix provided in the positive electrode body of Comparative Example 1 is higher than that of Example 1. The half width of the (003) plane of the specific matrix was 0.30, and the half width of the (104) plane was 0.27, which was almost the same as the half width of the positive electrode active material particles. That is, it can be said that the positive electrode body of Comparative Example 1 is a positive electrode body in which both the positive electrode active material particles and the matrix have substantially homogeneous crystallinity.

［比較例２の非水電解質電池］
正極活物質の前駆物質を溶解させた溶解液にＬｉＣｏＯ２粉末を混合しなかった点以外は、実施例１と同じ製造方法により焼結体を作製した。つまり、溶液法による合成によってＬｉＣｏＯ２からなる正極体を形成する方法であり、出来上がる正極体は、低結晶性（（００３）面の半値幅＝０．５１、（１０４）面の半値幅＝０．３９）で、かつ、均質的である。また、この方法では、厚さ１０μｍ以上の正極体を形成することが困難であるので、厚さ２０μｍの正極体を得るために重ね塗りを行う必要があった。 [Nonaqueous Electrolyte Battery of Comparative Example 2]
A sintered body was produced by the same production method as in Example 1 except that the LiCoO 2 powder was not mixed in a solution obtained by dissolving the precursor of the positive electrode active material. That is, this is a method of forming a positive electrode body made of LiCoO 2 by synthesis by a solution method, and the positive electrode body thus obtained has low crystallinity ((003) plane half-value width = 0.51, (104) plane half-value width = 0. .39) and is homogeneous. In addition, in this method, it is difficult to form a positive electrode body having a thickness of 10 μm or more, and therefore it is necessary to perform overcoating in order to obtain a positive electrode body having a thickness of 20 μm.

［充放電試験とその結果］
上述のようにして作製した実施例１，２および比較例１，２の非水電解質電池について、５０μＡの定電流で４．２Ｖまで充電し、３Ｖまで放電する操作を１サイクルとする充放電を５００サイクル繰り返す充放電試験を行った。そして、５００サイクル目の放電容量を１サイクル目の放電容量で除し、１００をかけることで容量維持率（％）を求めた。容量維持率が高いほど、充放電を開始した当初の放電容量を維持できる非水電解質電池、即ち、サイクル特性に優れた電池と言える。この充放電試験の結果を表１に示す。 [Charge / discharge test and results]
For the non-aqueous electrolyte batteries of Examples 1 and 2 and Comparative Examples 1 and 2 produced as described above, charging and discharging with a cycle of charging up to 4.2 V at a constant current of 50 μA and discharging to 3 V A charge / discharge test was repeated 500 cycles. Then, the discharge capacity at the 500th cycle was divided by the discharge capacity at the first cycle and multiplied by 100 to obtain the capacity retention rate (%). It can be said that the higher the capacity retention rate is, the non-aqueous electrolyte battery that can maintain the initial discharge capacity after the start of charging / discharging, that is, the battery with excellent cycle characteristics. The results of this charge / discharge test are shown in Table 1.

Figure 2011065787
Figure 2011065787

表１の結果から、高結晶性の正極活物質粒子と低結晶性のマトリックスとからなる正極体を備える実施例１，２の非水電解質電池は、高い放電容量を備え、かつ、容量維持率が高かった。   From the results shown in Table 1, the nonaqueous electrolyte batteries of Examples 1 and 2 having a positive electrode body composed of highly crystalline positive electrode active material particles and a low crystalline matrix have a high discharge capacity and a capacity retention rate. Was expensive.

一方、使用した正極体が正極活物質粒子とマトリックスとからなるものの、正極体を作製する際の焼結温度が実施例１，２の電池よりも高かった比較例２の電池は、インピーダンス値が極めて高く、充放電試験を行うことすらできなかった。これは、焼結時の温度が高かったために、マトリックスも高結晶性の結晶組織になったからではないかと推察される。   On the other hand, although the positive electrode used was composed of positive electrode active material particles and a matrix, the battery of Comparative Example 2 in which the sintering temperature when producing the positive electrode was higher than that of the batteries of Examples 1 and 2 had an impedance value. It was extremely expensive and could not even be charged / discharged. This is presumably because the matrix also has a highly crystalline structure due to the high temperature during sintering.

また、正極活物質粒子を含まない正極体、つまり、マトリックスのみで形成された正極体を使用した比較例２の電池は、初期放電容量（１サイクル目の放電容量）が低い上、５００サイクル後の容量維持率も５０％と低かった。   In addition, the battery of Comparative Example 2 using a positive electrode body that does not contain positive electrode active material particles, that is, a positive electrode body formed of only a matrix has a low initial discharge capacity (discharge capacity at the first cycle) and after 500 cycles. The capacity maintenance rate was as low as 50%.

なお、本発明の実施形態は、上述した実施形態に限定されるわけではなく、本発明の要旨を逸脱しない範囲で適宜変更等可能である。   The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.

本発明正極体を用いた非水電解質電池は、放電容量が高く、サイクル特性に優れるので、例えば携帯電話やモバイルパソコンなどの携帯機器の電源として好適に利用可能である。   The nonaqueous electrolyte battery using the positive electrode body of the present invention has a high discharge capacity and excellent cycle characteristics, and therefore can be suitably used as a power source for portable devices such as mobile phones and mobile personal computers.

１００ 非水電解質電池
１ 正極層 １１ 正極集電体 １２ 正極活物質層
２ 負極層
３ 電解質層
４ 緩衝層 DESCRIPTION OF SYMBOLS 100 Nonaqueous electrolyte battery 1 Positive electrode layer 11 Positive electrode collector 12 Positive electrode active material layer 2 Negative electrode layer 3 Electrolyte layer 4 Buffer layer

Claims (7)

非水電解質電池に用いられる焼結体からなる正極体であって、
高結晶性の正極活物質粒子と、
前記正極活物質粒子の間隙を埋める低結晶性の正極活物質からなるマトリックスと、
を備えることを特徴とする正極体。 A positive electrode body made of a sintered body used in a nonaqueous electrolyte battery,
Highly crystalline positive electrode active material particles;
A matrix made of a low crystalline positive electrode active material that fills the gaps between the positive electrode active material particles;
A positive electrode body comprising: 前記正極活物質粒子とマトリックスの組成はいずれも、ＬｉαＸβ(１−Ｘ)Ｏ２であることを特徴とする請求項１に記載の正極体。
αは、Ｃｏ，Ｎｉ，Ｍｎから選択される１種以上
βは、Ｆｅ，Ａｌから選択される１種以上
Ｘは、０．５以上、１．０以下 The positive electrode active Both material particles and the composition of the matrix is positive electrode according to claim 1, characterized in that the Liα X β (1-X) O 2.
α is one or more selected from Co, Ni and Mn β is one or more selected from Fe and Al X is 0.5 or more and 1.0 or less 前記正極活物質粒子と前記マトリックスの合計体積に占める前記正極活物質粒子の体積の割合は、９０％以上であることを特徴とする請求項１または２に記載の正極体。   The positive electrode body according to claim 1, wherein a ratio of a volume of the positive electrode active material particles to a total volume of the positive electrode active material particles and the matrix is 90% or more. 前記正極活物質粒子の平均粒径は、５〜２０μｍであることを特徴とする請求項１〜３のいずれか一項に記載の正極体。   4. The positive electrode body according to claim 1, wherein an average particle diameter of the positive electrode active material particles is 5 to 20 μm. 非水電解質電池に利用される正極体の製造方法であって、
正極活物質の前駆物質を溶解した溶液を用意する工程と、
高結晶性の正極活物質粒子を用意する工程と、
前記溶液と前記正極活物質粒子とを混合する混合工程と、
前記混合工程で得られた混合溶液を基板表面に塗工する塗工工程と、
前記混合溶液を焼結する焼結工程と、
を備えることを特徴とする正極体の製造方法。 A method for producing a positive electrode body used in a nonaqueous electrolyte battery,
Preparing a solution in which a precursor of the positive electrode active material is dissolved;
A step of preparing highly crystalline positive electrode active material particles;
A mixing step of mixing the solution and the positive electrode active material particles;
A coating step of coating the mixed solution obtained in the mixing step on the substrate surface;
A sintering step of sintering the mixed solution;
The manufacturing method of the positive electrode body characterized by the above-mentioned. 前記焼結工程における焼結温度は、４５０〜６５０℃であることを特徴とする請求項５に記載の正極体の製造方法。   The method for producing a positive electrode body according to claim 5, wherein a sintering temperature in the sintering step is 450 to 650 ° C. 前記混合工程は、焼結温度よりも低い温度で加熱しながら行なうことを特徴とする請求項５または６に記載の正極体の製造方法。   The method for producing a positive electrode body according to claim 5 or 6, wherein the mixing step is performed while heating at a temperature lower than a sintering temperature.
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Cited By (3)

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WO2013161350A1 (en) * 2012-04-27 2013-10-31 住友電気工業株式会社 Method for manufacturing non-aqueous electrolyte cell, and non-aqueous electrolyte cell
JP2014060020A (en) * 2012-09-18 2014-04-03 Toshiba Corp Nonaqueous electrolyte battery
EP3128581A1 (en) * 2015-08-04 2017-02-08 Samsung Electronics Co., Ltd. Cathode including sintered polycrystalline material, secondary battery including the same, and method of manufacturing the cathode

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WO2013161350A1 (en) * 2012-04-27 2013-10-31 住友電気工業株式会社 Method for manufacturing non-aqueous electrolyte cell, and non-aqueous electrolyte cell
JP2014060020A (en) * 2012-09-18 2014-04-03 Toshiba Corp Nonaqueous electrolyte battery
EP3128581A1 (en) * 2015-08-04 2017-02-08 Samsung Electronics Co., Ltd. Cathode including sintered polycrystalline material, secondary battery including the same, and method of manufacturing the cathode
CN106450271A (en) * 2015-08-04 2017-02-22 三星电子株式会社 Cathode, secondary battery including the cathode and method of manufacturing the cathode
EP3389118A1 (en) * 2015-08-04 2018-10-17 Samsung Electronics Co., Ltd. Cathode including sintered polycrystalline material and secondary battery including the same
US10147944B2 (en) 2015-08-04 2018-12-04 Samsung Electronics Co., Ltd. Cathode including sintered polycrystalline material, secondary battery including the cathode, and method of manufacturing the cathode
CN106450271B (en) * 2015-08-04 2021-07-16 三星电子株式会社 Positive electrode, secondary battery including the same, and method of preparing the same
US11133502B2 (en) 2015-08-04 2021-09-28 Samsung Electronics Co., Ltd. Cathode including sintered polycrystalline material, secondary battery including the cathode, and method of manufacturing the cathode
CN113555525A (en) * 2015-08-04 2021-10-26 三星电子株式会社 Positive electrode, secondary battery including the same, and method of preparing the same

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