JP2020013713A - Cathode active material and cathode active material thereof - Google Patents
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Abstract
Description
本発明は、正極活物質、および正極活物質の製造方法に関する。さらに詳しくは、リチウムイオン二次電池、電気二重層キャパシタ等の充電可能な電気化学素子に用いる正極活物質および正極活物質の製造方法に関する。 The present invention relates to a positive electrode active material and a method for producing a positive electrode active material. More specifically, the present invention relates to a positive electrode active material used for a rechargeable electrochemical device such as a lithium ion secondary battery and an electric double layer capacitor, and a method for producing the positive electrode active material.
従来、高エネルギー密度を有する二次電池として、リチウムイオン二次電池が幅広く普及している。そして近年、使用機器の消費エネルギー増加に伴い、リチウムイオン二次電池にはさらなる高エネルギー密度化が切望されている。 BACKGROUND ART Conventionally, lithium ion secondary batteries have been widely used as secondary batteries having a high energy density. In recent years, with the increase in energy consumption of equipment used, further increase in energy density of lithium ion secondary batteries has been desired.
これに対して、正極および負極の集電体やセパレータの厚みを薄くする等の対応が実施されているが、その他に、電極を構成する活物質についても検討が進められている。 In response to this, measures such as reducing the thickness of the current collectors and separators of the positive electrode and the negative electrode have been implemented. In addition, studies have been made on active materials forming the electrodes.
例えば、正極活物質については、従来、充放電で利用されてきた領域の電位と比較して、より高電位な領域の容量を利用する物質が検討されている。これにより、電池の充電電圧を上昇させることができ、放電容量を増やすことが可能となり、その結果、エネルギー密度を向上させることができる。 For example, as for a positive electrode active material, a material that utilizes the capacity of a region having a higher potential compared to the potential of a region used in charge and discharge has been studied. Thereby, the charge voltage of the battery can be increased, and the discharge capacity can be increased. As a result, the energy density can be improved.
このような正極活物質としては、例えば、リチウムニッケルマンガンコバルト酸化物(LiNixCoyMn1−x−yO2)が提案されている(特許文献1参照)。しかしながら、LiNixCoyMn1−x−yO2等の三元系の正極活物質には、経年劣化および充放電によるサイクル劣化により、抵抗上昇と容量低下の問題を有している。 As such a positive electrode active material, for example, lithium nickel manganese cobalt oxide (LiNi x Co y Mn 1- x-y O 2) has been proposed (see Patent Document 1). However, a ternary positive electrode active material such as LiNi x Co y Mn 1-xy O 2 has a problem of an increase in resistance and a decrease in capacity due to aging deterioration and cycle deterioration due to charge and discharge.
ここで、充放電によるリチウムイオンの伝導抵抗の上昇を抑制する方法として、活物質の表面を、リチウムイオン伝導性無機固体電解質やLiNbO3等により被覆する方法が提案されている(特許文献3および4参照)。 Here, as a method of suppressing an increase in the conduction resistance of lithium ions due to charge and discharge, a method of coating the surface of an active material with a lithium ion conductive inorganic solid electrolyte, LiNbO 3 or the like has been proposed (Patent Document 3 and 4).
しかしながら、リチウムイオン伝導性無機固体電解質による被覆では、経年劣化およびサイクル劣化による正極活物質の表面劣化は未だ十分に抑制されておらず、さらなる劣化抑制の方法が求められていた。 However, in the case of coating with a lithium ion conductive inorganic solid electrolyte, surface deterioration of the positive electrode active material due to aging and cycle deterioration has not yet been sufficiently suppressed, and a method of further suppressing deterioration has been required.
本発明は上記の背景技術に鑑みてなされたものであり、その目的は、高容量で、経年劣化およびサイクル劣化による表面劣化が抑制された正極活物質、およびそ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 background art, and an object of the present invention is to provide a cathode active material having a high capacity, in which surface deterioration due to aging and cycle deterioration is suppressed, and a method for producing the same. .
本発明者らは、正極活物質となるLiNixCoyMn1−x−yO2の表面組成に着目し、LiNixCoyMn1−x−yO2の表面に存在するNi、Co、およびMnからなる群より選ばれる少なくとも1種の原子を、正極活物質の層構造を安定化したり、相転位を抑制する機能を発揮する特定の原子と置換すれば、高容量で、表面劣化が抑制された高耐久性の正極活物質が得られることを見出し、本発明を完成させるに至った。 The present inventors have, Ni which focuses on surface composition of LiNi x Co y Mn 1-x -y O 2 as a positive electrode active material, present in LiNi x Co y Mn 1-x -y O 2 of the surface, Co And at least one atom selected from the group consisting of Mn and Mn is replaced with a specific atom exhibiting a function of stabilizing the layer structure of the positive electrode active material or suppressing phase transition, resulting in high capacity and surface degradation. The present inventors have found that a highly durable positive electrode active material in which is suppressed is obtained, and have completed the present invention.
すなわち本発明は、下記化学式(1)で示される正極活物質である。
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種である。)
That is, the present invention is a positive electrode active material represented by the following chemical formula (1).
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. )
前記化学式(1)におけるAは、前記正極活物質の表面に存在していてもよい。 A in the chemical formula (1) may be present on the surface of the positive electrode active material.
また別の本発明は、上記の正極活物質を含む、リチウムイオン二次電池用正極である。 Still another aspect of the present invention is a positive electrode for a lithium ion secondary battery, including the above positive electrode active material.
また別の本発明は、上記のリチウムイオン二次電池用正極と、電解質と、負極と、を備えるリチウムイオン二次電池である。 Still another aspect of the present invention is a lithium ion secondary battery including the above-described positive electrode for a lithium ion secondary battery, an electrolyte, and a negative electrode.
また別の本発明は、下記化学式(2)で示される正極活物質の表面に存在する、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子を、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子と置換して、下記化学式(1)で示される正極活物質を得る置換工程を有する、正極活物質の製造方法である。
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種である。)
[化2]
LiNixCoyMnzO2 (2)
(式中、0<x<1、0<y<1、0<z<1、かつx+y+z=1である。)
In another aspect of the present invention, at least one atom selected from the group consisting of Ni, Co, and Mn present on the surface of the positive electrode active material represented by the following chemical formula (2) is converted into C, Al, Mg, Si , Zr, Ti, B, Ag, Au, and at least one atom selected from the group consisting of halogen atoms to obtain a positive electrode active material represented by the following chemical formula (1). It is a method for producing a substance.
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. )
[Formula 2]
LiNi x Co y Mn z O 2 (2)
(Where 0 <x <1, 0 <y <1, 0 <z <1, and x + y + z = 1)
前記置換工程では、ドーピング、固溶添加、置換固溶、荷電粒子注入、プラズマ照射、レーザ光照射、および電位印加からなる群より選ばれる少なくとも1種を実施するものであってもよい。 In the substitution step, at least one selected from the group consisting of doping, solid solution addition, substitution solid solution, charged particle injection, plasma irradiation, laser beam irradiation, and potential application may be performed.
本発明の正極活物質は、高容量であると同時に、経年劣化およびサイクル劣化による表面劣化が抑制されたものである。したがって、本発明の正極活物質を用いたリチウムイオン二次電池は、エネルギー密度が高く、容量低下が抑制された電池となる。 The positive electrode active material of the present invention has high capacity and, at the same time, suppresses surface deterioration due to aging and cycle deterioration. Therefore, a lithium ion secondary battery using the positive electrode active material of the present invention has a high energy density and a reduced capacity.
以下、本発明の実施形態について説明する。 Hereinafter, embodiments of the present invention will be described.
<正極活物質の製造方法>
本発明の正極活物質の製造方法は、下記化学式(2)で示される正極活物質の表面に存在する、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子を、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子と置換して、下記化学式(1)で示される正極活物質を得る置換工程を有する、正極活物質の製造方法である。
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種である。)
[化2]
LiNixCoyMnzO2 (2)
(式中、0<x<1、0<y<1、0<z<1、かつx+y+z=1である。)
<Production method of positive electrode active material>
In the method for producing a positive electrode active material of the present invention, at least one atom selected from the group consisting of Ni, Co, and Mn present on the surface of the positive electrode active material represented by the following chemical formula (2) is converted to C, Al , Mg, Si, Zr, Ti, B, Ag, Au, and at least one atom selected from the group consisting of halogen atoms to obtain a positive electrode active material represented by the following chemical formula (1). This is a method for producing a positive electrode active material.
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. )
[Formula 2]
LiNi x Co y Mn z O 2 (2)
(Where 0 <x <1, 0 <y <1, 0 <z <1, and x + y + z = 1)
[原料]
本発明の上記化学式(1)で示される正極活物質の原料となる上記化学式(2)で示される正極活物質は、正極活物質として公知のリチウム含有金属酸化物である。上記化学式(2)で示される正極活物質は、層状岩塩型構造を有する。
[material]
The cathode active material represented by the chemical formula (2), which is a raw material of the cathode active material represented by the chemical formula (1) of the present invention, is a lithium-containing metal oxide known as a cathode active material. The positive electrode active material represented by the above chemical formula (2) has a layered rock salt type structure.
[置換工程]
本発明の正極活物質の製造方法における置換工程は、原料となる上記化学式(2)で示される正極活物質の表面に存在する、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子を、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子と置換して、上記化学式(1)で示される正極活物質を得る工程である。
[Replacement step]
The substitution step in the method for producing a positive electrode active material of the present invention includes at least one kind selected from the group consisting of Ni, Co, and Mn present on the surface of the positive electrode active material represented by the chemical formula (2) as a raw material. The atom is replaced with at least one atom selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom, to form a positive electrode active material represented by the above chemical formula (1). This is the step of obtaining the substance.
本発明において、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子を、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子と置換する方法は、特に限定されるものではない。例えば、置換したい原子をドーパントとするドーピング、固溶添加させて元素置換させる方法や、これらの原子にエネルギーを与えて打ち込む方法がある。具体的には、置換したい原子、原子からなるクラスター、原子を含むガス、化合物、スラリー等を正極活物質であるLiNixCoyMnzO2と接触させ、光、熱、電気、圧力等のエネルギーを与えることで正極活物質の元素を置換させる方法、あるいは、原子、クラスター、荷電粒子等に運動エネルギーを与えて打ち込む方法が挙げられる。 In the present invention, at least one atom selected from the group consisting of Ni, Co, and Mn is selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. The method of substituting at least one atom is not particularly limited. For example, there are a method of doping with an atom to be replaced as a dopant, a method of solid solution addition for element replacement, and a method of applying energy to these atoms for implantation. Specifically, an atom to be replaced, a cluster of atoms, a gas containing an atom, a compound, a slurry, or the like is brought into contact with a positive electrode active material, LiNi x Co y Mn z O 2 , to generate light, heat, electricity, pressure, or the like. There is a method in which the element of the positive electrode active material is substituted by applying energy, or a method in which kinetic energy is applied to atoms, clusters, charged particles, and the like to drive them.
すなわち、置換工程では、ドーピング、固溶添加、置換固溶、荷電粒子注入、プラズマ照射、レーザ光照射、および電位印加からなる群より選ばれる少なくとも1種を実施することが好ましい。 That is, in the substitution step, at least one selected from the group consisting of doping, solid solution addition, substitution solid solution, charged particle injection, plasma irradiation, laser beam irradiation, and potential application is preferably performed.
(温度)
置換工程における温度は、100〜1400℃の範囲とすることが好ましく、200〜1200℃の範囲とすることがさらに好ましく、300〜1000℃の範囲とすることが特に好ましい。200℃よりも低い場合には、活物質の元素置換が進行せず、1000℃より高い場合には、活物質中の融点を超えるため好ましくない。
(temperature)
The temperature in the substitution step is preferably in the range of 100 to 1400C, more preferably in the range of 200 to 1200C, and particularly preferably in the range of 300 to 1000C. When the temperature is lower than 200 ° C., the element substitution of the active material does not progress, and when the temperature is higher than 1000 ° C., the melting point in the active material is exceeded, which is not preferable.
(圧力)
置換工程における圧力は、真空〜300MPaの範囲とすることが好ましく、真空〜200MPaの範囲とすることがさらに好ましく、真空〜150MPaの範囲とすることが特に好ましい。300MPaよりも高い場合には、加圧装置破損につながるため好ましくない。
(pressure)
The pressure in the replacement step is preferably in the range of vacuum to 300 MPa, more preferably in the range of vacuum to 200 MPa, and particularly preferably in the range of vacuum to 150 MPa. If the pressure is higher than 300 MPa, it is not preferable because the pressure device is damaged.
(時間)
置換工程における処理時間は、0.1〜48時間の範囲とすることが好ましく、0.1〜12時間の範囲とすることがさらに好ましく、0.1〜8時間の範囲とすることが特に好ましい。0.1時間よりも短い場合には、元素置換が不十分となり、48時間よりも長い場合には、内部まで置換してしまうため好ましくない。
(time)
The treatment time in the replacement step is preferably in the range of 0.1 to 48 hours, more preferably in the range of 0.1 to 12 hours, and particularly preferably in the range of 0.1 to 8 hours. . When the time is shorter than 0.1 hour, the element replacement becomes insufficient, and when the time is longer than 48 hours, the inside is replaced undesirably.
(イオン注入)
置換工程において、置換元素を、荷電粒子、原子、分子として活物質に注入する場合には、250eV〜10MeVに加速し、打ち込むことができる。その際、活物質を溶融、分解温度以下に加熱して、注入を容易にしてもよい。
(Ion implantation)
In the substitution step, when the substitution element is injected into the active material as charged particles, atoms, or molecules, the acceleration can be performed at 250 eV to 10 MeV, and the implantation can be performed. At this time, the active material may be heated to a temperature lower than the melting and decomposition temperature to facilitate the injection.
<正極活物質>
本発明の正極活物質は、下記化学式(1)で示される正極活物質である。
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種である。)
<Positive electrode active material>
The positive electrode active material of the present invention is a positive electrode active material represented by the following chemical formula (1).
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. )
本発明の正極活物質は、正極活物質として公知のリチウム含有金属酸化物である上記化学式(2)で示される正極活物質を原料とし、その結晶構造は維持されていることから、層状岩塩型構造を有する。また、菱面体晶系であり、空間群R−3mを有する。 The positive electrode active material of the present invention uses a positive electrode active material represented by the above chemical formula (2), which is a known lithium-containing metal oxide as a positive electrode active material, as a raw material, and its crystal structure is maintained. Having a structure. Further, it is a rhombohedral system and has a space group R-3m.
本発明の正極活物質は、原料となる上記化学式(2)で示される物質の表面に存在する、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子が、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子に置換されたものである。上記化学式(1)で示される本発明の正極活物質においては、Aが、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子となる。 In the positive electrode active material of the present invention, at least one atom selected from the group consisting of Ni, Co, and Mn present on the surface of the material represented by the above chemical formula (2) is C, Al, Mg. , Si, Zr, Ti, B, Ag, Au, and a halogen atom. In the cathode active material of the present invention represented by the chemical formula (1), A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. Atom.
C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子は、層状岩塩型構造を有する本発明の正極活物質の層構造を安定化したり、劣化の原因と考えられる相転位を抑制する機能を発揮する原子である。このため、本発明の正極活物質は、リチウムイオン導電性と容量の両方を兼ね備えた物質となる上、表面劣化が抑制された高耐久性の正極活物質となる。 C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and halogen atoms stabilize the layer structure of the positive electrode active material of the present invention having a layered rock-salt structure, and are considered to cause deterioration. An atom that has the function of suppressing dislocations. Therefore, the positive electrode active material of the present invention is a material having both lithium ion conductivity and capacity, and is a highly durable positive electrode active material with suppressed surface deterioration.
なお、本発明においては、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる原子は、1種単独であっても2種以上であってもよい。中では、活物質の層構造の安定化に寄与するAlや、相転移抑制に効果のあるZrは好ましい。また、導電性に寄与するC等も好ましい。なお、複数の機能を持たせるため、これらを混在させてもよい。 In the present invention, the atoms selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and halogen atoms may be used alone or in combination of two or more. Is also good. Among them, Al that contributes to stabilization of the layer structure of the active material and Zr that has an effect of suppressing phase transition are preferable. Further, C and the like that contribute to conductivity are also preferable. Note that these may be mixed in order to have a plurality of functions.
(原子の置換量)
本発明の正極活物質は、Ni、Co、およびMnからなる群より選ばれる少なくとも1種の原子が、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種の原子に置換された構造を有するが、その置換量を示す上記化学式(1)におけるwは、通常、0<w<1.0であり、0.1<w<=0.9であることが好ましく、0.4<w<=0.9であることがさらに好ましい。
(Atom substitution amount)
In the positive electrode active material of the present invention, at least one atom selected from the group consisting of Ni, Co, and Mn is composed of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. It has a structure substituted by at least one kind of atom selected from the group, and w in the above chemical formula (1) indicating the substitution amount is usually 0 <w <1.0, and 0.1 <w < = 0.9, more preferably 0.4 <w <= 0.9.
原子の置換量wが0.9を超え、かつ原子が置換された層の厚みが1000nmを超える場合には、リチウムイオン導電性が大きく低下し、活物質内部への挿入、脱離が困難となってしまい、電池としての機能が損なわれてしまう。 When the atom substitution amount w exceeds 0.9 and the thickness of the atom-substituted layer exceeds 1000 nm, lithium ion conductivity is greatly reduced, and insertion and desorption into the active material are difficult. As a result, the function as a battery is impaired.
なお、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる複数の原子で置換する場合には、原子の置換量wは、それぞれの原子の置換量の合計を意味する。 In the case of substitution with a plurality of atoms selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom, the substitution amount w of each atom is It means the total replacement amount.
(置換原子の存在状態)
置換による導入された原子である上記化学式(1)におけるAは、正極活物質の表面に存在している。ここで、正極活物質の表面とは、最表面から1000nmの深さまでを意味する。本発明においては、最表面から200nmの深さまでに、置換された原子の40%以上が存在しており、最表面から600nmの深さまでに80%以上が、最表面から1000nmの深さまでに90%以上が、存在している。
(Presence state of substituted atom)
A in the above chemical formula (1), which is an atom introduced by substitution, exists on the surface of the positive electrode active material. Here, the surface of the positive electrode active material means from the outermost surface to a depth of 1000 nm. In the present invention, 40% or more of the substituted atoms exist from the outermost surface to a depth of 200 nm, and 80% or more from the outermost surface to a depth of 600 nm and 90% from the outermost surface to a depth of 1000 nm. More than% are present.
本発明においては、正極活物質の表面付近に、層状岩塩型構造を有する本発明の正極活物質の層構造を安定化したり、劣化の原因と考えられる相転位を抑制する機能を発揮する原子が存在することにより、正極活物質の表層部分の組成が、下層の組成とは異なるものとなり、その結果、置換により導入された原子を含む層によって正極活物質の表面に被膜が形成された状態となる。しかしながら、置換により導入された原子は正極活物質そのものとなっていることから、コーティング等により形成した被膜とは異なり、物理的にも化学的にも強固な層となっている。その結果、容量および出力は高いままで、表面劣化を抑制することが可能となる。 In the present invention, in the vicinity of the surface of the positive electrode active material, atoms exhibiting a function of stabilizing the layer structure of the positive electrode active material of the present invention having a layered rock salt type structure or suppressing a phase transition considered to be a cause of deterioration are included. Due to the presence, the composition of the surface layer portion of the positive electrode active material becomes different from the composition of the lower layer, and as a result, a state in which a film is formed on the surface of the positive electrode active material by the layer containing atoms introduced by substitution. Become. However, since the atoms introduced by the substitution become the positive electrode active material itself, unlike a film formed by coating or the like, it is a physically and chemically strong layer. As a result, it is possible to suppress surface degradation while keeping the capacity and output high.
<リチウムイオン二次電池用正極>
本発明のリチウムイオン二次電池用正極は、本発明の正極活物質を含むことを特徴とする。本発明の正極活物質を含んでいれば、その他の構成は特に限定されるものではない。
<Positive electrode for lithium ion secondary battery>
A positive electrode for a lithium ion secondary battery of the present invention is characterized by containing the positive electrode active material of the present invention. Other configurations are not particularly limited as long as they include the positive electrode active material of the present invention.
例えば、本発明のリチウムイオン二次電池用正極は、本発明の正極活物質以外に、他の成分を含んでいてもよい。他の成分としては、例えば、導電助剤やバインダー等が挙げられる。 For example, the positive electrode for a lithium ion secondary battery of the present invention may contain other components in addition to the positive electrode active material of the present invention. Other components include, for example, conductive aids and binders.
本発明のリチウムイオン二次電池用正極は、例えば、本発明の正極活物質と、導電助剤と、バインダーとを含む混合物を、集電体上に塗布して乾燥することにより得ることができる。 The positive electrode for a lithium ion secondary battery of the present invention can be obtained, for example, by applying a mixture containing the positive electrode active material of the present invention, a conductive additive, and a binder on a current collector and drying the mixture. .
<リチウムイオン二次電池>
本発明のリチウムイオン二次電池は、本発明の正極活物質を含むリチウムイオン二次電池用正極と、電解質と、負極と、を備える。
<Lithium ion secondary battery>
The lithium ion secondary battery of the present invention includes a positive electrode for a lithium ion secondary battery containing the positive electrode active material of the present invention, an electrolyte, and a negative electrode.
[負極]
本発明のリチウムイオン二次電池に適用する負極は、特に限定されるものではなく、リチウムイオン二次電池の負極として機能するものであればよい。
[Negative electrode]
The negative electrode applied to the lithium ion secondary battery of the present invention is not particularly limited as long as it functions as a negative electrode of the lithium ion secondary battery.
例えば、電極を構成できる材料から、本発明の正極活物質を含むリチウムイオン二次電池用正極と比較して、卑な電位を示すものを負極として選択し、任意の電池を構成することができる。 For example, from a material that can form an electrode, as compared to the positive electrode for a lithium ion secondary battery containing the positive electrode active material of the present invention, a material that shows a lower potential can be selected as a negative electrode, and an arbitrary battery can be formed. .
[電解質]
本発明のリチウムイオン二次電池を構成する電解質は、液体状の電解液であっても、固体状の固体電解質であってもよい。リチウムイオン二次電池を構成できる電解質であれば、特に問題なく適用することができる。
[Electrolytes]
The electrolyte constituting the lithium ion secondary battery of the present invention may be a liquid electrolyte or a solid electrolyte. As long as the electrolyte can constitute a lithium ion secondary battery, it can be applied without any particular problem.
次に、本発明の実施例について説明するが、本発明はこれら実施例等に限定されるものではない。 Next, examples of the present invention will be described, but the present invention is not limited to these examples.
<実施例1〜4>
正極活物質であるLi(Ni0.5Co0.2Mn0.3)O2を、トリメチルアルミニウム溶液に分散させた後、減圧乾燥することで、トリメチルアルミニウムで覆われた正極活物質を得た。
<Examples 1 to 4>
Li (Ni 0.5 Co 0.2 Mn 0.3 ) O 2 , which is a positive electrode active material, is dispersed in a trimethylaluminum solution, and then dried under reduced pressure to obtain a positive electrode active material covered with trimethylaluminum. Was.
トリメチルアルミニウムで覆われた正極活物質を、プラズマ発生装置内に投入してプラズマ照射を実施し、Li(Ni0.5Co0.2Mn0.3)O2においてアルミニウムとの原子置換を行った。原子置換量wは、プラズマのエネルギーおよび処理時間を制御することで変化させることができる。 The positive electrode active material covered with trimethylaluminum is charged into a plasma generator to perform plasma irradiation, and Li (Ni 0.5 Co 0.2 Mn 0.3 ) O 2 is subjected to atomic substitution with aluminum. Was. The atomic replacement amount w can be changed by controlling the energy of the plasma and the processing time.
[置換量の測定]
得られたアルミニウム置換正極活物質の置換量wについて、以下の測定条件で表面X線光電子分光(XPS)分析を実施し、光電子ピーク面積強度と相対感度係数から、元素組成比(原子%)を算出した。
(測定条件)
分析装置: アルバック・ファイ社製 全自動走査型X線光電子分光分析装置 Quantera SXM
X線源: 単色化Al Kα
X線出力: 24.6W
X線ビーム系: 100μmΦ
光電子取り出し角: 45°
[Measurement of replacement amount]
Surface X-ray photoelectron spectroscopy (XPS) analysis was performed on the replacement amount w of the obtained aluminum-substituted positive electrode active material under the following measurement conditions, and the element composition ratio (atomic%) was determined from the photoelectron peak area intensity and the relative sensitivity coefficient. Calculated.
(Measurement condition)
Analyzer: ULVAC-PHI, Inc. Fully automatic scanning X-ray photoelectron spectrometer Quantera SXM
X-ray source: Monochromatic Al Kα
X-ray output: 24.6W
X-ray beam system: 100 μmΦ
Photoelectron extraction angle: 45 °
表1に、アルミニウムの置換量wを示す。 Table 1 shows the replacement amount w of aluminum.
[容量維持率の測定]
得られたアルミニウム置換正極活物質を用いて、以下の要領で二次電池セルを作製し、その容量維持率(放電レート0.2C、測定温度25℃)を測定した。
[Measurement of capacity retention rate]
Using the obtained aluminum-substituted positive electrode active material, a secondary battery cell was produced in the following manner, and its capacity retention ratio (discharge rate 0.2 C, measurement temperature 25 ° C.) was measured.
(正極の作製)
得られた正極活物質94質量部と、導電助剤としてアセチレンブラック3質量部と、結着剤としてフッ化ビニリデン3質量部とを混合し、得られた混合物を適量のN−メチル−2−ピロリドンに分散させて、スラリーを作製した。集電体として厚み12μmのアルミ箔を準備し、作製したスラリーを集電体に塗布し、100℃で60分乾燥させて、正極とした。
(Preparation of positive electrode)
94 parts by mass of the obtained positive electrode active material, 3 parts by mass of acetylene black as a conductive auxiliary, and 3 parts by mass of vinylidene fluoride as a binder were mixed, and the obtained mixture was mixed with an appropriate amount of N-methyl-2- It was dispersed in pyrrolidone to prepare a slurry. An aluminum foil having a thickness of 12 μm was prepared as a current collector, and the prepared slurry was applied to the current collector and dried at 100 ° C. for 60 minutes to obtain a positive electrode.
(電池の作製)
負極にグラファイト電極を用いて、電解液として、エチレンカーボネート、ジメチルカーボネート、エチルメチルカーボネートを、体積比3:4:3で混合した溶媒に、1モルのLiPF6を溶解した溶液を用いて、電池を作製した。
(Production of battery)
Using a graphite electrode as a negative electrode and a solution obtained by dissolving 1 mol of LiPF 6 in a solvent obtained by mixing ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate in a volume ratio of 3: 4: 3 as an electrolyte, Was prepared.
(容量維持率の測定)
作製した電池につき、初期容量の測定を実施した。その後、SOC=100%(4.2V)、60℃で52日間保管し、保管後の電池容量を測定した。初期容量を100%として、保管後の残容量につき、容量維持率を計算した。結果を図1に示す。
(Measurement of capacity retention rate)
The initial capacity of the manufactured battery was measured. Thereafter, the battery was stored at SOC = 100% (4.2 V) at 60 ° C. for 52 days, and the battery capacity after storage was measured. With the initial capacity as 100%, the capacity retention rate was calculated for the remaining capacity after storage. The results are shown in FIG.
<比較例1>
Li(Ni0.5Co0.2Mn0.3)O2を用いて、実施例1と同様にして二次電池セルを作製し、その容量維持率(放電レート0.2C、測定温度25℃)を測定した。結果を、図1に示す。
<Comparative Example 1>
Using Li (Ni 0.5 Co 0.2 Mn 0.3 ) O 2 , a secondary battery cell was fabricated in the same manner as in Example 1, and the capacity retention (discharge rate 0.2 C, measurement temperature 25 ° C.) was measured. The results are shown in FIG.
<実施例5〜8>
処理チャンバー内に、原料となる正極活物質であるLi(Ni0.5Co0.2Mn0.3)O2を配置した。また、同チャンバー内に、アーク放電式の蒸発元となるグラファイト棒を配置し、減圧してアーク放電を発生させて炭素クラスターを合成した。得られた炭素クラスターを電子衝撃法によりイオン化し、電界により加速して正極活物質に衝突させ、正極活物質表面の原子を炭素原子で置換し、炭素原子を導入した。炭素の置換量は、電界の電圧、照射時間、雰囲気温度、真空度によって変化させることができる。
<Examples 5 to 8>
Li (Ni 0.5 Co 0.2 Mn 0.3 ) O 2 , which is a positive electrode active material as a raw material, was disposed in the processing chamber. In the same chamber, a graphite rod as an evaporation source of the arc discharge type was arranged, and the pressure was reduced to generate an arc discharge, thereby synthesizing a carbon cluster. The obtained carbon cluster was ionized by an electron impact method, accelerated by an electric field and collided with the positive electrode active material, replacing atoms on the positive electrode active material surface with carbon atoms, and introducing carbon atoms. The carbon substitution amount can be changed depending on the electric field voltage, irradiation time, ambient temperature, and degree of vacuum.
[置換量の測定]
得られた炭素置換正極活物質の置換量wについて、実施例1と同様にして表面X線光電子分光(XPS)分析を実施し、得られた結果から算出した。
[Measurement of replacement amount]
Surface X-ray photoelectron spectroscopy (XPS) analysis was performed on the replacement amount w of the obtained carbon-substituted positive electrode active material in the same manner as in Example 1, and calculated from the obtained results.
表2に、炭素の置換量wを示す。 Table 2 shows the carbon substitution amount w.
(容量維持率の測定)
得られた炭素置換正極活物質を用いて、実施例1と同様にして二次電池セルを作製し、その容量維持率(放電レート0.2C、測定温度25℃)を測定した。結果を、図2に示す。
(Measurement of capacity retention rate)
Using the obtained carbon-substituted positive electrode active material, a secondary battery cell was fabricated in the same manner as in Example 1, and the capacity retention ratio (discharge rate 0.2 C, measurement temperature 25 ° C.) was measured. The results are shown in FIG.
Claims (6)
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種である。) A positive electrode active material represented by the following chemical formula (1).
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom. )
[化1]
LiNixCoyMnzO2Aw (1)
(式中、0<x<1、0<y<1、0<z<1、0<w<1、かつx+y+z+w=1であり、
Aは、C、Al、Mg、Si、Zr、Ti、B、Ag、Au、およびハロゲン原子からなる群より選ばれる少なくとも1種であり、
0<w<1である。)
[化2]
LiNixCoyMnzO2 (2)
(式中、0<x<1、0<y<1、0<z<1、かつx+y+z=1である。) At least one atom selected from the group consisting of Ni, Co, and Mn present on the surface of the positive electrode active material represented by the following chemical formula (2) is represented by C, Al, Mg, Si, Zr, Ti, B, A method for producing a positive electrode active material, comprising a substitution step of substituting at least one atom selected from the group consisting of Ag, Au, and a halogen atom to obtain a positive electrode active material represented by the following chemical formula (1).
[Formula 1]
LiNi x Co y Mn z O 2 A w (1)
(Where 0 <x <1, 0 <y <1, 0 <z <1, 0 <w <1, and x + y + z + w = 1,
A is at least one selected from the group consisting of C, Al, Mg, Si, Zr, Ti, B, Ag, Au, and a halogen atom;
0 <w <1. )
[Formula 2]
LiNi x Co y Mn z O 2 (2)
(Where 0 <x <1, 0 <y <1, 0 <z <1, and x + y + z = 1)
The positive electrode active material according to claim 5, wherein in the substitution step, at least one selected from the group consisting of doping, solid solution addition, substitution solid solution, charged particle injection, plasma irradiation, laser beam irradiation, and potential application is performed. The method of manufacturing the substance.
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Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003007299A (en) * | 2001-06-14 | 2003-01-10 | Samsung Sdi Co Ltd | Active material for battery, manufacturing method therefor, and manufacturing method of the battery |
JP2008159560A (en) * | 2006-11-28 | 2008-07-10 | Sony Corp | Method of manufacturing positive electrode active material |
JP2015069958A (en) * | 2013-10-01 | 2015-04-13 | 日立マクセル株式会社 | Positive electrode material for nonaqueous secondary batteries, manufacturing method thereof, positive electrode mixture layer for nonaqueous secondary batteries arranged by use of positive electrode material for nonaqueous secondary batteries, positive electrode for nonaqueous secondary batteries, and nonaqueous secondary battery |
JP2015088383A (en) * | 2013-10-31 | 2015-05-07 | 三星電子株式会社Samsung Electronics Co.,Ltd. | Positive electrode for lithium ion secondary batteries, and lithium ion secondary battery |
WO2015163356A1 (en) * | 2014-04-22 | 2015-10-29 | 三菱化学株式会社 | Positive electrode active material for non-aqueous secondary cell, and non-aqueous secondary cell |
WO2016035853A1 (en) * | 2014-09-03 | 2016-03-10 | 三井金属鉱業株式会社 | Positive-electrode active material for lithium secondary cell |
JP2017041425A (en) * | 2015-08-21 | 2017-02-23 | 株式会社日本触媒 | Lithium ion secondary battery |
JP2017142997A (en) * | 2016-02-10 | 2017-08-17 | 戸田工業株式会社 | Lithium nickelate-carbon composite positive electrode active material particle powder, and manufacturing method thereof, and nonaqueous electrolyte secondary battery |
JP2018502421A (en) * | 2014-12-05 | 2018-01-25 | エルジー・ケム・リミテッド | Positive electrode active material, method for producing the same, and lithium secondary battery including the same |
-
2018
- 2018-07-19 JP JP2018135638A patent/JP2020013713A/en active Pending
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003007299A (en) * | 2001-06-14 | 2003-01-10 | Samsung Sdi Co Ltd | Active material for battery, manufacturing method therefor, and manufacturing method of the battery |
JP2008159560A (en) * | 2006-11-28 | 2008-07-10 | Sony Corp | Method of manufacturing positive electrode active material |
JP2015069958A (en) * | 2013-10-01 | 2015-04-13 | 日立マクセル株式会社 | Positive electrode material for nonaqueous secondary batteries, manufacturing method thereof, positive electrode mixture layer for nonaqueous secondary batteries arranged by use of positive electrode material for nonaqueous secondary batteries, positive electrode for nonaqueous secondary batteries, and nonaqueous secondary battery |
JP2015088383A (en) * | 2013-10-31 | 2015-05-07 | 三星電子株式会社Samsung Electronics Co.,Ltd. | Positive electrode for lithium ion secondary batteries, and lithium ion secondary battery |
WO2015163356A1 (en) * | 2014-04-22 | 2015-10-29 | 三菱化学株式会社 | Positive electrode active material for non-aqueous secondary cell, and non-aqueous secondary cell |
WO2016035853A1 (en) * | 2014-09-03 | 2016-03-10 | 三井金属鉱業株式会社 | Positive-electrode active material for lithium secondary cell |
JP2018502421A (en) * | 2014-12-05 | 2018-01-25 | エルジー・ケム・リミテッド | Positive electrode active material, method for producing the same, and lithium secondary battery including the same |
JP2017041425A (en) * | 2015-08-21 | 2017-02-23 | 株式会社日本触媒 | Lithium ion secondary battery |
JP2017142997A (en) * | 2016-02-10 | 2017-08-17 | 戸田工業株式会社 | Lithium nickelate-carbon composite positive electrode active material particle powder, and manufacturing method thereof, and nonaqueous electrolyte secondary battery |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021153746A1 (en) | 2020-01-30 | 2021-08-05 | 日本製鉄株式会社 | Hot rolled steel sheet and production method thereof |
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