JP2015176856A - Negative electrode, method of manufacturing the same, and power storage device - Google Patents

Negative electrode, method of manufacturing the same, and power storage device Download PDF

Info

Publication number
JP2015176856A
JP2015176856A JP2014055000A JP2014055000A JP2015176856A JP 2015176856 A JP2015176856 A JP 2015176856A JP 2014055000 A JP2014055000 A JP 2014055000A JP 2014055000 A JP2014055000 A JP 2014055000A JP 2015176856 A JP2015176856 A JP 2015176856A
Authority
JP
Japan
Prior art keywords
negative electrode
active material
protective layer
electrode active
material layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2014055000A
Other languages
Japanese (ja)
Inventor
英二 水谷
Eiji Mizutani
英二 水谷
英明 篠田
Hideaki Shinoda
英明 篠田
祐樹 杉本
Yuki Sugimoto
祐樹 杉本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Industries Corp
Original Assignee
Toyota Industries Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Industries Corp filed Critical Toyota Industries Corp
Priority to JP2014055000A priority Critical patent/JP2015176856A/en
Publication of JP2015176856A publication Critical patent/JP2015176856A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Abstract

PROBLEM TO BE SOLVED: To provide a negative electrode which is formed by covering a negative electrode active material layer with an electrode protective layer and inhibits the negative electrode active material layer from being exposed on the surface, and also to provide a method of manufacturing the negative electrode.SOLUTION: An electrode protective layer is provided on a negative electrode active material layer, the density of the electrode protective layer is made to be 1.45 g/cmor more and less than 4 g/cm, the unit weight of the electrode protective layer is made to be 0.5 mg/cmor more and 2.0 mg/cmor less, and furthermore the surface roughness of the negative active material layer is made to be 0.1 μm or more and 10 μm or less, thereby uniformly covering the negative electrode active material layer with the electrode protective layer.

Description

本発明は、リチウムイオン二次電池等の蓄電装置に用いられる負極、当該負極を製造する方法、および当該負極を含む蓄電装置に関する。   The present invention relates to a negative electrode used for a power storage device such as a lithium ion secondary battery, a method for manufacturing the negative electrode, and a power storage device including the negative electrode.

蓄電装置における負極の表面には、短絡防止等の目的で、絶縁性を持つ電極保護層を設ける場合がある。例えば特許文献1には、負極活物質層の表面を電極保護層(コート層)で覆う技術が提案されている。特許文献1に紹介されている電極保護層は、粒子状の絶縁性材料(絶縁性粒子と呼ぶ)およびバインダで構成された多孔質層である。電解液や電荷担体は電極保護層の細孔を通じて負極活物質層の内外に移動し得る。   An electrode protection layer having an insulating property may be provided on the surface of the negative electrode in the power storage device for the purpose of preventing a short circuit. For example, Patent Document 1 proposes a technique for covering the surface of the negative electrode active material layer with an electrode protective layer (coat layer). The electrode protective layer introduced in Patent Document 1 is a porous layer composed of a particulate insulating material (referred to as insulating particles) and a binder. The electrolytic solution and the charge carrier can move in and out of the negative electrode active material layer through the pores of the electrode protective layer.

ところで、電極保護層は絶縁性を有し負極活物質層は導電性を有するため、負極に電極保護層を設ける場合には、負極活物質層の表面を電極保護層でむらなく覆わなければ、負極表面の電気抵抗を均一にし難い。つまり、負極の表面のなかで負極活物質層が露出している部分は、電極保護層が露出している部分に比べて電気抵抗が低いため、負極の表面のなかで負極活物質層が露出している部分には電流が集中する。すると、負極活物質層が露出している部分に電荷担体(例えば蓄電池がリチウムイオン二次電池であればリチウム)が析出し易くなる。析出した電荷担体は充放電に関与し難くなるため、電荷担体の析出により蓄電装置の容量が低下する可能性がある。また、電荷担体の種類によっては、電荷担体が析出することで、短絡が生じた際の発熱量が増大する可能性もある。このため負極の表面における負極活物質層の露出部分を低減し得る技術が望まれている。   By the way, since the electrode protective layer has insulation and the negative electrode active material layer has conductivity, when the electrode protective layer is provided on the negative electrode, unless the surface of the negative electrode active material layer is uniformly covered with the electrode protective layer, It is difficult to make the electric resistance of the negative electrode surface uniform. In other words, the portion of the negative electrode surface where the negative electrode active material layer is exposed has a lower electrical resistance than the portion of the negative electrode surface where the electrode protection layer is exposed, so the negative electrode active material layer is exposed within the negative electrode surface. The current concentrates on the part where it is. Then, charge carriers (for example, lithium if the storage battery is a lithium ion secondary battery) are likely to be deposited on the portion where the negative electrode active material layer is exposed. Since the deposited charge carriers are less likely to be involved in charge / discharge, the capacity of the power storage device may be reduced due to the deposition of the charge carriers. In addition, depending on the type of charge carrier, the charge carrier may be deposited, which may increase the amount of heat generated when a short circuit occurs. For this reason, the technique which can reduce the exposed part of the negative electrode active material layer in the surface of a negative electrode is desired.

特開2009−181756号公報JP 2009-181756 A

本発明は上記事情に鑑みてなされたものであり、負極活物質層を電極保護層で覆ってなり、かつ、表面における負極活物質層の露出が抑制された負極、およびその製造方法を提供することを目的とする。   The present invention has been made in view of the above circumstances, and provides a negative electrode in which a negative electrode active material layer is covered with an electrode protective layer and exposure of the negative electrode active material layer on the surface is suppressed, and a method for producing the same. For the purpose.

本発明の発明者等は、鋭意研究の結果、電極保護層の密度および目付量、ならびに負極活物質層の表面粗さを調整することで、負極表面における負極活物質層の露出を抑制できることを見出した。   As a result of intensive studies, the inventors of the present invention have confirmed that the exposure of the negative electrode active material layer on the negative electrode surface can be suppressed by adjusting the density and basis weight of the electrode protective layer and the surface roughness of the negative electrode active material layer. I found it.

つまり、上記課題を解決する本発明の負極は、
集電体と、前記集電体上に設けられている負極活物質層と、前記負極活物質層上に設けられている電極保護層と、を含み、
前記電極保護層は、絶縁性粒子とバインダとを含み、
前記電極保護層の密度は1.45g/cm以上4g/cm未満であり、
前記電極保護層の目付量は0.5mg/cm以上2.0mg/cm以下であり、
前記負極活物質層の表面粗さRaは0.1μm以上10μm以下であるものである。
That is, the negative electrode of the present invention that solves the above problems is
A current collector, a negative electrode active material layer provided on the current collector, and an electrode protective layer provided on the negative electrode active material layer,
The electrode protective layer includes insulating particles and a binder,
The electrode protective layer has a density of 1.45 g / cm 3 or more and less than 4 g / cm 3 ;
The basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2 or less,
The surface roughness Ra of the negative electrode active material layer is not less than 0.1 μm and not more than 10 μm.

また、上記課題を解決する本発明の蓄電装置は、上記した本発明の負極を含むものである。   Moreover, the power storage device of the present invention that solves the above-described problems includes the above-described negative electrode of the present invention.

本発明の負極は、以下の(1)を備えるのが好ましい。
(1)前記負極活物質層の表面粗さRaは0.1μm以上2.0μm以下である。
さらに、上記課題を解決する本発明の負極の製造方法は、
負極活物質を含む負極活物質層を集電体上に形成する負極活物質層形成工程と、
絶縁性粒子およびバインダを含む電極保護層を前記負極活物質層上に形成する電極保護層形成工程と、を含み、
前記負極活物質層形成工程において、前記負極活物質層の表面粗さを0.1μm以上10μm以下にし、
前記電極保護層形成工程において、前記電極保護層の密度を1.45g/cm以上4g/cm未満にし、前記電極保護層の目付量を0.5mg/cm以上2.0mg/cm以下にする方法である。
The negative electrode of the present invention preferably comprises the following (1).
(1) The surface roughness Ra of the negative electrode active material layer is 0.1 μm or more and 2.0 μm or less.
Furthermore, the manufacturing method of the negative electrode of the present invention that solves the above problems is
A negative electrode active material layer forming step of forming a negative electrode active material layer containing a negative electrode active material on a current collector;
An electrode protective layer forming step of forming an electrode protective layer containing insulating particles and a binder on the negative electrode active material layer, and
In the negative electrode active material layer forming step, the surface roughness of the negative electrode active material layer is 0.1 μm or more and 10 μm or less,
In the electrode protective layer forming step, the density of the electrode protective layer is 1.45 g / cm 3 or more and less than 4 g / cm 3 , and the basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2. The method is as follows.

本発明の負極は、負極活物質層を電極保護層で覆ってなり、かつ、表面における負極活物質層の露出が抑制されたものである。   In the negative electrode of the present invention, the negative electrode active material layer is covered with an electrode protective layer, and the exposure of the negative electrode active material layer on the surface is suppressed.

電極保護層の密度および目付量が本発明の範囲よりも小さく、かつ、負極活物質層の表面粗さが本発明の範囲よりも大きい負極を用いたリチウムイオン二次電池を充放電し、充放電後の負極の表面を撮像したSEM像である。Charge and discharge a lithium ion secondary battery using a negative electrode in which the density and basis weight of the electrode protective layer are smaller than the range of the present invention and the surface roughness of the negative electrode active material layer is larger than the range of the present invention. It is the SEM image which imaged the surface of the negative electrode after discharge. 図1における該当部分を拡大したSEM像である。It is the SEM image which expanded the applicable part in FIG. 試験1の負極の表面のSEM像である。2 is a SEM image of the surface of a negative electrode in Test 1. 試験4の負極の表面のSEM像である。4 is a SEM image of the negative electrode surface in Test 4. 試験1〜試験10の電極保護層の目付量、膜厚および密度と、評価試験の結果との関係を表すグラフである。It is a graph showing the relationship between the fabric weight, the film thickness, and the density of the electrode protective layer of Test 1 to Test 10, and the result of the evaluation test.

本発明の負極は、負極活物質層上に電極保護層を設けたものである。本発明の負極においては、電極保護層の密度が1.45g/cm以上4g/cm未満であるようにし、かつ、電極保護層の目付量を0.5mg/cm以上2.0mg/cm以下とした。本発明の負極において、電極保護層は比較的高密度であり、かつ、電極保護層の目付量は比較的多い。電極保護層をこのようにしたことで、負極活物質層を電極保護層でむらなく(或いは略むらなく)覆うことができ、負極表面における負極活物質層の露出を抑制できる。 In the negative electrode of the present invention, an electrode protective layer is provided on the negative electrode active material layer. In the negative electrode of the present invention, the density of the electrode protective layer is 1.45 g / cm 3 or more and less than 4 g / cm 3 , and the basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2. cm 2 or less. In the negative electrode of the present invention, the electrode protective layer has a relatively high density, and the basis weight of the electrode protective layer is relatively large. By making the electrode protective layer in this way, the negative electrode active material layer can be covered with the electrode protective layer evenly (or substantially without unevenness), and exposure of the negative electrode active material layer on the negative electrode surface can be suppressed.

つまり、負極活物質層の表面には多少なりとも凹凸が存在する。したがって、電極保護層の厚さが薄ければ、負極活物質層の凸部分を電極保護層で覆いきることができず、電極保護層の上側に負極活物質層が部分的に突出する場合がある。この場合、負極活物質層を電極保護層でむらなく覆うことはできず、負極表面に負極活物質層が露出する。また、電極保護層の密度が過小であり、電極保護層が粗であれば、電極保護層自体の隙を通じて負極活物質層が負極表面に露出する場合がある。本発明の負極においては、電極保護層の目付量、すなわち、負極活物質層の表面単位面積当りに積層される電極保護層の量を多くしたことで、電極保護層の厚さを充分に厚くし、負極活物質層の表面の凹凸を電極保護層で埋めることができる。また、電極保護層の密度を大きくして電極保護層を密にしたことで、電極保護層自体の隙を小さくし、当該隙を通じて負極活物質層が負極表面に露出できないようにした。このため本発明の負極においては、負極表面における負極活物質層の露出を抑制できる。   That is, the surface of the negative electrode active material layer is somewhat uneven. Therefore, if the electrode protective layer is thin, the convex portion of the negative electrode active material layer cannot be covered with the electrode protective layer, and the negative electrode active material layer may partially protrude above the electrode protective layer. is there. In this case, the negative electrode active material layer cannot be uniformly covered with the electrode protective layer, and the negative electrode active material layer is exposed on the negative electrode surface. If the density of the electrode protective layer is too low and the electrode protective layer is rough, the negative electrode active material layer may be exposed on the negative electrode surface through the gap of the electrode protective layer itself. In the negative electrode of the present invention, the basis weight of the electrode protective layer, that is, the amount of the electrode protective layer laminated per unit surface area of the negative electrode active material layer is increased, thereby sufficiently increasing the thickness of the electrode protective layer. And the unevenness | corrugation of the surface of a negative electrode active material layer can be filled up with an electrode protective layer. In addition, by increasing the density of the electrode protective layer to make the electrode protective layer dense, the gap of the electrode protective layer itself is reduced so that the negative electrode active material layer cannot be exposed to the negative electrode surface through the gap. For this reason, in the negative electrode of this invention, exposure of the negative electrode active material layer in the negative electrode surface can be suppressed.

さらに、本発明の負極においては、負極活物質層の表面粗さRaは0.1μm以上10μm以下である。凹凸の大きな負極活物質層に上記した電極保護層を組み合わせる場合には、電極保護層による負極活物質層の露出抑制効果が充分に発揮されない可能性があるが、表面粗さがこのような範囲にある負極活物質層に上記した電極保護層を組み合わせれば、電極保護層による負極活物質層の露出抑制効果は充分に発揮される。なお、表面粗さRaがこの範囲にあれば、負極活物質層の表面には比較的凹凸が少なく、負極活物質層の表面は滑らかであると言える。つまり、本発明の負極においては、負極活物質層の凹凸自体を小さくしたことで、負極表面における負極活物質層の露出をより一層抑制できる。   Furthermore, in the negative electrode of the present invention, the surface roughness Ra of the negative electrode active material layer is 0.1 μm or more and 10 μm or less. When the above-mentioned electrode protective layer is combined with a negative electrode active material layer having large irregularities, the effect of suppressing the exposure of the negative electrode active material layer by the electrode protective layer may not be sufficiently exhibited, but the surface roughness is in such a range. If the above-mentioned electrode protective layer is combined with the negative electrode active material layer, the effect of suppressing the exposure of the negative electrode active material layer by the electrode protective layer is sufficiently exhibited. If the surface roughness Ra is in this range, it can be said that the surface of the negative electrode active material layer is relatively uneven, and the surface of the negative electrode active material layer is smooth. That is, in the negative electrode of the present invention, the unevenness of the negative electrode active material layer itself is reduced, whereby the exposure of the negative electrode active material layer on the negative electrode surface can be further suppressed.

参考までに、電極保護層の密度および目付量が本発明の範囲よりも小さく、負極活物質層の表面粗さが本発明の範囲よりも大きい負極をリチウムイオン二次電池の負極として用い、当該リチウムイオン二次電池を充放電した。すると、図1に示すように負極の表面には負極活物質層が露出した。また、負極の表面に露出した負極活物質層を拡大したところ、図2に示すように、負極活物質層にはリチウムの析出がみられた。   For reference, a negative electrode in which the density and basis weight of the electrode protective layer is smaller than the range of the present invention and the surface roughness of the negative electrode active material layer is larger than the range of the present invention is used as the negative electrode of the lithium ion secondary battery. The lithium ion secondary battery was charged and discharged. Then, as shown in FIG. 1, the negative electrode active material layer was exposed on the surface of the negative electrode. Further, when the negative electrode active material layer exposed on the surface of the negative electrode was enlarged, precipitation of lithium was observed in the negative electrode active material layer as shown in FIG.

以下に、本発明を実施するための形態を説明する。なお、特に断らない限り、本明細書に記載された数値範囲「x〜y」は、下限xおよび上限yをその範囲に含む。そして、これらの上限値および下限値、ならびに実施例中に列記した数値も含めてそれらを任意に組み合わせることで数値範囲を構成し得る。さらに数値範囲内から任意に選択した数値を上限、下限の数値とすることができる。以下、必要に応じて、正極と負極とを総称して電極と呼ぶ。   Below, the form for implementing this invention is demonstrated. Unless otherwise specified, the numerical range “x to y” described in this specification includes the lower limit x and the upper limit y. The numerical range can be configured by arbitrarily combining these upper limit value and lower limit value and the numerical values listed in the examples. Furthermore, numerical values arbitrarily selected from the numerical value range can be used as upper and lower numerical values. Hereinafter, the positive electrode and the negative electrode are collectively referred to as electrodes as necessary.

〔負極〕
本発明の負極は、通常の蓄電装置における負極と同様に、集電体、負極活物質層、および電極保護層を含む。
[Negative electrode]
The negative electrode of the present invention includes a current collector, a negative electrode active material layer, and an electrode protective layer, similarly to the negative electrode in a normal power storage device.

集電体および負極活物質層は特に限定されず、通常の蓄電装置における負極と同様に構成すれば良い。具体的には、集電体は、蓄電装置の放電または充電の間、電極に電流を流し続けるための化学的に不活性な電子高伝導体である。集電体としては、銀、銅、金、アルミニウム、タングステン、コバルト、亜鉛、ニッケル、鉄、白金、錫、インジウム、チタン、ルテニウム、タンタル、クロム、モリブデンから選ばれる少なくとも一種、またはその合金が例示される。例えば、ステンレス鋼などを選択することもできる。   The current collector and the negative electrode active material layer are not particularly limited, and may be configured similarly to the negative electrode in a normal power storage device. Specifically, the current collector is a chemically inert electronic high conductor that keeps current flowing through the electrode during discharging or charging of the power storage device. Examples of the current collector include at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, and molybdenum, or an alloy thereof. Is done. For example, stainless steel can be selected.

集電体は、箔状、シート状、フィルム状、線状、棒状、メッシュ状などの形態をとることができる。そのため、集電体として、例えば、銅箔、ニッケル箔、アルミニウム箔、ステンレス箔などの金属箔を好適に用いることができる。さらに、集電体の表面に集電体コート層を形成しても良い。集電体コート層の材料は、導電性に優れるものを選択するのが良い。後述する正極に関しても同様である。   The current collector can take the form of a foil, a sheet, a film, a line, a bar, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector. Further, a current collector coating layer may be formed on the surface of the current collector. As the material for the current collector coating layer, a material having excellent conductivity is preferably selected. The same applies to the positive electrode described later.

負極活物質層は、集電体上に設けられ、負極活物質を含むとともに、バインダや導電助剤等の添加剤を含み得る。集電体、バインダおよび添加剤に関しては、後述する正極に関しても同様である。   The negative electrode active material layer is provided on the current collector, and includes a negative electrode active material and may include additives such as a binder and a conductive additive. The same applies to the positive electrode described later with respect to the current collector, binder and additive.

負極活物質としては、電荷担体を吸蔵および放出し得る一般的なものを使用可能である。例えば、蓄電装置がリチウムイオン二次電池である場合には、負極活物質として、電荷担体としてのリチウムイオンを吸蔵および放出し得る材料を選択すれば良い。より詳しくは、リチウム等の電荷担体と合金化可能な元素(単体)、当該元素を含む合金、または当該元素を含む化合物であれば良い。具体的には、負極活物質として、Liや、炭素、ケイ素、ゲルマニウム、錫などの14族元素、アルミニウム、インジウムなどの13族元素、亜鉛、カドミウムなどの12族元素、アンチモン、ビスマスなどの15族元素、マグネシウム、カルシウムなどのアルカリ土類金属、銀、金などの11族元素をそれぞれ単体で採用すれば良い。ケイ素等を負極活物質に採用すると、ケイ素1原子が複数のリチウムと反応するため、高容量の活物質となる。しかしその一方で、リチウムの吸蔵および放出に伴って負極活物質の体積の膨張および収縮が顕著となる等の問題が生じるおそれがある。したがって、当該恐れの軽減のために、ケイ素などの単体に遷移金属等の他の元素を組み合わせた合金または化合物を負極活物質として採用するのも好適である。合金または化合物の具体例としては、Ag−Sn合金、Cu−Sn合金、Co−Sn合金等の錫系材料、各種黒鉛などの炭素系材料、ケイ素単体と二酸化ケイ素に不均化するSiO(0.3≦x≦1.6)などのケイ素系材料、ケイ素単体若しくはケイ素系材料と炭素系材料を組み合わせた複合体が挙げられる。また、負極活物質して、Nb、TiO、LiTi12、WO、MoO、Fe等の酸化物、または、Li3−xN(M=Co、Ni、Cu)で表される窒化物を採用しても良い。負極活物質として、これらのものの一種以上を使用することができる。 As the negative electrode active material, a general material that can occlude and release charge carriers can be used. For example, when the power storage device is a lithium ion secondary battery, a material that can occlude and release lithium ions as a charge carrier may be selected as the negative electrode active material. More specifically, any element (single element) that can be alloyed with a charge carrier such as lithium, an alloy containing the element, or a compound containing the element may be used. Specifically, as the negative electrode active material, a group 14 element such as Li, carbon, silicon, germanium or tin, a group 13 element such as aluminum or indium, a group 12 element such as zinc or cadmium, 15 such as antimony or bismuth, etc. A group element, an alkaline earth metal such as magnesium and calcium, and a group 11 element such as silver and gold may be employed alone. When silicon or the like is employed as the negative electrode active material, one silicon atom reacts with a plurality of lithiums, so that a high-capacity active material is obtained. On the other hand, however, problems such as significant expansion and contraction of the volume of the negative electrode active material may occur with the insertion and extraction of lithium. Therefore, in order to reduce the fear, it is also preferable to employ an alloy or a compound in which another element such as a transition metal is combined with a simple substance such as silicon as the negative electrode active material. Specific examples of the alloy or compound include tin-based materials such as Ag—Sn alloy, Cu—Sn alloy, and Co—Sn alloy, carbon-based materials such as various graphites, SiO x (disproportionated to silicon simple substance and silicon dioxide). Examples thereof include silicon-based materials such as 0.3 ≦ x ≦ 1.6), silicon alone, or composites obtained by combining silicon-based materials and carbon-based materials. Further, as the negative electrode active material, an oxide such as Nb 2 O 5 , TiO 2 , Li 4 Ti 5 O 12 , WO 2 , MoO 2 , Fe 2 O 3 , or Li 3-x M x N (M = A nitride represented by (Co, Ni, Cu) may be employed. One or more of these materials can be used as the negative electrode active material.

なお、負極活物質および後述する正極活物質がともに電荷担体を含まない場合、またはこれらに含まれる電荷担体の量が必要とされる量よりも少ない場合には、負極および/または正極に電荷担体を予め添加しておくのが良い。例えば、本発明の蓄電装置がリチウムイオン二次電池である場合、リチウムを含まない負極活物質を用いる場合には、負極および/または正極に、公知の方法によって、予め電荷担体としてのリチウムイオンを添加しておく必要がある。リチウムは、イオンの状態で添加しても良いし、金属等の非イオンの状態で添加しても良い。例えば、リチウム箔を正極および/または負極に貼り付けるなどして一体化しても良い。他の電荷担体を用いる場合に関しても同様である。   When both the negative electrode active material and the positive electrode active material described later do not contain charge carriers, or when the amount of charge carriers contained therein is less than the required amount, the negative electrode and / or the positive electrode have charge carriers. Is preferably added in advance. For example, when the power storage device of the present invention is a lithium ion secondary battery, when a negative electrode active material that does not contain lithium is used, lithium ions as a charge carrier are previously added to the negative electrode and / or positive electrode by a known method. It is necessary to add. Lithium may be added in an ionic state or in a nonionic state such as a metal. For example, lithium foil may be integrated with the positive electrode and / or the negative electrode. The same applies to the case where other charge carriers are used.

バインダは、負極活物質を集電体の表面に繋ぎ止める役割を果たすものである。バインダとしては、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、フッ素ゴム等の含フッ素樹脂、ポリプロピレン、ポリエチレン等の熱可塑性樹脂、ポリイミド、ポリアミドイミド等のイミド系樹脂、アルコキシシリル基含有樹脂を例示することができる。また、バインダとして、親水基を有するポリマーを採用しても良い。親水基を有するポリマーの親水基としては、カルボキシル基、スルホ基、シラノール基、アミノ基、水酸基、リン酸基などリン酸系の基などが例示される。   The binder plays a role of connecting the negative electrode active material to the surface of the current collector. Examples of the binder include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins. it can. Moreover, you may employ | adopt the polymer which has a hydrophilic group as a binder. Examples of the hydrophilic group of the polymer having a hydrophilic group include a phosphate group such as a carboxyl group, a sulfo group, a silanol group, an amino group, a hydroxyl group, and a phosphate group.

負極活物質層中のバインダの配合割合は、質量比で、負極活物質:バインダ=1:0.005〜1:0.3であるのが好ましい。バインダが少なすぎると負極活物質層の成形性が低下し、また、バインダが多すぎると負極のエネルギ密度が低くなるためである。   The blending ratio of the binder in the negative electrode active material layer is preferably a mass ratio of negative electrode active material: binder = 1: 0.005 to 1: 0.3. This is because if the amount of the binder is too small, the moldability of the negative electrode active material layer is lowered, and if the amount of the binder is too large, the energy density of the negative electrode is lowered.

導電助剤は、負極の導電性を高めるために添加される。そのため、導電助剤は、負極の導電性が不足する場合に任意に加えれば良く、負極の導電性が十分に優れている場合には加えなくても良い。導電助剤は化学的に不活性な電子高伝導体であれば良く、炭素質微粒子であるカーボンブラック、黒鉛、アセチレンブラック、ケッチェンブラック(登録商標)、気相法炭素繊維(Vapor Grown Carbon Fiber:VGCF)、および各種金属粒子などを例示できる。これらの導電助剤を単独でまたは2種以上組み合わせて負極活物質層に添加することができる。負極活物質層中の導電助剤の配合割合は、質量比で、負極活物質:導電助剤=1:0.01〜1:0.5であるのが好ましい。導電助剤が少なすぎると効率のよい導電パスを形成できず、また、導電助剤が多すぎると負極活物質層の成形性が悪くなるとともに負極のエネルギ密度が低くなるためである。   A conductive additive is added to increase the conductivity of the negative electrode. Therefore, the conductive auxiliary agent may be optionally added when the negative electrode has insufficient conductivity, and may not be added when the negative electrode has sufficiently high conductivity. The conductive auxiliary agent may be any chemically inert electronic high conductor, such as carbon black, graphite, acetylene black, ketjen black (registered trademark), vapor grown carbon fiber (Vapor Carbon Carbon Fiber). : VGCF), and various metal particles. These conductive assistants can be added to the negative electrode active material layer alone or in combination of two or more. The blending ratio of the conductive additive in the negative electrode active material layer is preferably a negative electrode active material: conductive additive = 1: 0.01 to 1: 0.5 in mass ratio. This is because if the amount of the conductive auxiliary is too small, an efficient conductive path cannot be formed, and if the amount of the conductive auxiliary is too large, the formability of the negative electrode active material layer is deteriorated and the energy density of the negative electrode is lowered.

負極は、負極活物質を含む負極合材を集電体の表面に配置し、乾燥することで形成できる。或いは、乾燥後に電極密度を高めるべく圧縮しても良い。これは後述する正極に関しても同様である。   The negative electrode can be formed by disposing a negative electrode mixture containing a negative electrode active material on the surface of the current collector and drying it. Or you may compress in order to raise an electrode density after drying. The same applies to the positive electrode described later.

負極合材は、負極活物質、バインダ、溶剤、その他の添加剤、および、必要に応じて導電助剤を含み、ペースト状をなす。   The negative electrode mixture includes a negative electrode active material, a binder, a solvent, other additives, and, if necessary, a conductive additive, and forms a paste.

溶剤は、主として、負極合材の粘度調整のために配合される。一般的には、固形分を予め混合し、次いで溶剤を加えることで、負極合材を集電体に塗布等するのに適した粘度にする。溶剤としては、N−メチル−2−ピロリドン(NMP)、メタノール、メチルイソブチルケトン(MIBK)などが使用可能である。   The solvent is mainly blended for adjusting the viscosity of the negative electrode mixture. In general, the solid content is mixed in advance, and then a solvent is added to obtain a viscosity suitable for applying the negative electrode mixture to the current collector. As the solvent, N-methyl-2-pyrrolidone (NMP), methanol, methyl isobutyl ketone (MIBK) and the like can be used.

負極合材を集電体の表面に配置する方法としては、塗布、積層、載置、スプレー等の一般的な方法を用いることができる。例えばロールコート法、ディップコート法、ドクターブレード法、スプレーコート法、カーテンコート法などの従来から公知の方法を選択し得る。   As a method for disposing the negative electrode mixture on the surface of the current collector, a general method such as coating, stacking, placing, spraying, or the like can be used. For example, conventionally known methods such as a roll coating method, a dip coating method, a doctor blade method, a spray coating method, and a curtain coating method can be selected.

本発明の負極における負極活物質層の表面粗さRaは0.1μm以上10μm以下であり、好ましくは0.1μm以上2.0μm以下であるのが良い。さらに好ましくは0.1μm以上1.0μm以下であるのが良い。上述したように、負極活物質層の表面粗さを小さくすることで、負極表面における負極活物質層の露出を抑制できる。負極活物質層の露出抑制のみを考慮すると、負極活物質層の表面粗さに下限値はない。しかし、負極活物質層には電荷担体や電解液が通過する孔が必要であり、また、負極活物質層の構造上、負極活物質表面にはある程度の凹凸が存在する。上記した負極活物質層の表面粗さRaの下限値は、これらを考慮した値である。   The surface roughness Ra of the negative electrode active material layer in the negative electrode of the present invention is 0.1 μm or more and 10 μm or less, preferably 0.1 μm or more and 2.0 μm or less. More preferably, it is 0.1 μm or more and 1.0 μm or less. As described above, exposure of the negative electrode active material layer on the negative electrode surface can be suppressed by reducing the surface roughness of the negative electrode active material layer. Considering only suppression of exposure of the negative electrode active material layer, there is no lower limit to the surface roughness of the negative electrode active material layer. However, the negative electrode active material layer requires holes through which charge carriers and electrolytes pass, and due to the structure of the negative electrode active material layer, there are some irregularities on the surface of the negative electrode active material. The lower limit value of the surface roughness Ra of the negative electrode active material layer described above is a value considering these.

負極は、上述したように、集電体上に負極合材を載置した後、乾燥することで形成される。また場合によっては乾燥後さらに圧縮して形成される。負極活物質層が圧縮されてなるものであれば、負極活物質層の表面粗さは圧縮後の表面粗さを意味する。また、負極活物質層が圧縮工程を経ないのであれば、乾燥後の表面粗さが負極活物質層の表面粗さである。何れの場合にも、負極活物質層の表面粗さは、さらにその表面に後述する電極保護層を設けた後の負極活物質層の表面粗さと略一致する。また、負極活物質層の表面粗さは、負極合材に含まれる各種固形分の粒径やバインダの配合量、圧縮する際の圧力や温度等によって適宜調整できる。   As described above, the negative electrode is formed by placing the negative electrode mixture on the current collector and then drying it. In some cases, it may be further compressed after drying. If the negative electrode active material layer is compressed, the surface roughness of the negative electrode active material layer means the surface roughness after compression. Moreover, if the negative electrode active material layer does not go through the compression step, the surface roughness after drying is the surface roughness of the negative electrode active material layer. In any case, the surface roughness of the negative electrode active material layer substantially coincides with the surface roughness of the negative electrode active material layer after an electrode protective layer described later is further provided on the surface. In addition, the surface roughness of the negative electrode active material layer can be adjusted as appropriate depending on the particle size of various solids contained in the negative electrode mixture, the blending amount of the binder, the pressure and temperature during compression, and the like.

電極保護層は、負極活物質層上に設けられ、絶縁性粒子とバインダとを含む。絶縁性粒子は、粒子状をなし、少なくとも表面が絶縁体で構成されたものである。絶縁性粒子は、電極活物質として機能しないもの、つまり、電荷担体の吸蔵および放出に関与しないものを用いるのが好ましい。絶縁性粒子としては、例えば、アルミナ(Al)、シリカ(SiO)、チタニア(TiO)、ジルコニア(ZrO)、マグネシア(MgO)から選ばれる少なくとも一種のセラミック材料からなる粒子を選択することもできるし、その他の絶縁性材料からなる粒子を選択することもできる。例えば、各種の金属元素または非金属元素の酸化物、炭化物、珪化物、窒化物であり、かつ、非導電性(つまり絶縁性)であるものを1種または複数種用いた粒子を選択できる。さらには、各種導電性材料からなる粒子を上記した何れかの絶縁性材料でコートした粒子を選択することもできる。上記の各粒子は単独で用いても良いし複数種併用しても良い。コストや耐久性等を考慮すると、絶縁性粒子として、絶縁性材料からなる粒子を選択するのが好ましく、上述したセラミック材料からなる少なくとも一種の粒子を選択するのがより好ましい。なお、ここで言う粒子とは小形であることを意味し、粒状、球状、板状、棒状、柱状等を含む概念であり、そのアスペクト比等は特に問わない。絶縁性材料が大形であれば、電極保護層を高密度にするのが困難であるため、絶縁性材料には小形であることつまり粒子状であることが要求される。つまり絶縁性粒子の粒径には好ましい範囲が存在する。具体的には、絶縁性粒子の平均粒径は0.1μm〜10μm程度であるのが好ましく、0.3μm〜1μm程度であるのがより好ましい。なお、特に説明のない場合、本明細書でいう平均粒径とは、レーザー光回折法による粒度分布測定における質量平均粒子径を指す。 The electrode protective layer is provided on the negative electrode active material layer and includes insulating particles and a binder. The insulating particles are in the form of particles, and at least the surface is composed of an insulator. It is preferable to use insulating particles that do not function as electrode active materials, that is, particles that do not participate in insertion and extraction of charge carriers. As the insulating particles, for example, particles made of at least one ceramic material selected from alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), zirconia (ZrO), and magnesia (MgO) are selected. It is also possible to select particles made of other insulating materials. For example, it is possible to select particles using one or more kinds of oxides, carbides, silicides, and nitrides of various metal elements or nonmetal elements that are nonconductive (that is, insulating). Furthermore, particles obtained by coating particles made of various conductive materials with any of the above insulating materials can be selected. Each of the above particles may be used alone or in combination. In consideration of cost, durability, and the like, it is preferable to select particles made of an insulating material as insulating particles, and it is more preferable to select at least one kind of particles made of the ceramic material described above. In addition, the particle | grains said here mean that it is small, and is a concept including a granular form, spherical shape, plate shape, rod shape, column shape, etc., The aspect ratio etc. are not ask | required in particular. If the insulating material is large, it is difficult to increase the density of the electrode protective layer. Therefore, the insulating material is required to be small, that is, in the form of particles. That is, there is a preferable range for the particle size of the insulating particles. Specifically, the average particle diameter of the insulating particles is preferably about 0.1 μm to 10 μm, and more preferably about 0.3 μm to 1 μm. In addition, when there is no description in particular, the average particle diameter as used in this specification refers to the mass average particle diameter in the particle size distribution measurement by a laser beam diffraction method.

本発明の負極における電極保護層の密度は1.45g/cm以上4g/cm未満であり、電極保護層の目付量は0.5mg/cm以上2.0mg/cm以下である。電極保護層の密度および目付量をこのようにすることで、負極表面における負極活物質層の露出を抑制できる。電極保護層の密度は、1.45g/cm以上4g/cm未満であるのがより好ましく、1.5g/cm以上2.0g/cm未満であるのがさらに好ましい。電極保護層の目付量は0.55mg/cm以上6mg/cm以下であるのがより好ましく、0.60mg/cm以上2mg/cm以下であるのがさらに好ましい。 The density of the electrode protective layer in the negative electrode of the present invention is 1.45 g / cm 3 or more and less than 4 g / cm 3 , and the basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2 or less. By setting the density and basis weight of the electrode protective layer in this way, exposure of the negative electrode active material layer on the negative electrode surface can be suppressed. The density of the electrode protective layer is more preferably 1.45 g / cm 3 or more and less than 4 g / cm 3 , and further preferably 1.5 g / cm 3 or more and less than 2.0 g / cm 3 . Basis weight of the electrode protective layer is more preferably not more than 0.55 mg / cm 2 or more 6 mg / cm 2, and even more preferably 0.60 mg / cm 2 or more 2 mg / cm 2 or less.

なお、電極保護層の目付量とは、負極活物質層上に設けられている電極保護層自体の量を指す。例えば、電極保護層が乾燥工程等を経て形成され、電極保護層の材料(電極保護合材と呼ぶ)の一部、例えば溶剤等が電極保護層中に存在しない場合には、当該存在しない材料の質量は目付量に含まれない。したがって、電極保護層の目付量は、負極活物質層上に塗布した電極保護合材の固形分の質量(mg)を、負極活物質層の塗布面積(cm)で除した値と言い換えることもできる。 The basis weight of the electrode protective layer refers to the amount of the electrode protective layer itself provided on the negative electrode active material layer. For example, when the electrode protective layer is formed through a drying process or the like, and a part of the material of the electrode protective layer (referred to as an electrode protective compound), such as a solvent, does not exist in the electrode protective layer, the non-existing material The mass of is not included in the basis weight. Therefore, the basis weight of the electrode protective layer is paraphrased as a value obtained by dividing the solid content (mg) of the electrode protective composite applied on the negative electrode active material layer by the application area (cm 2 ) of the negative electrode active material layer. You can also.

同様に、電極保護層の密度とは、負極活物質層上に設けられている電極保護層自体の密度を指す。電極保護層の密度は、負極活物質層上に塗布した電極保護合材の固形分の質量(g)を、負極活物質層上に設けられている電極保護層の体積(cm)で除した値と言い換えることもできる。 Similarly, the density of the electrode protective layer refers to the density of the electrode protective layer itself provided on the negative electrode active material layer. The density of the electrode protective layer is obtained by dividing the mass (g) of the solid content of the electrode protective composite applied on the negative electrode active material layer by the volume (cm 3 ) of the electrode protective layer provided on the negative electrode active material layer. In other words, it can be rephrased.

負極活物質層の露出抑制の観点からは、電極保護層は密である程良いと考えられるが、電極保護層には電荷担体や電解液の通過を許容する孔が必要である。このため電極保護層の密度には上限値がある。また、エネルギ効率等の電池性能を考慮すると、電極保護層の目付量にも上限値がある。上記した電極保護層の密度および目付量の上限値は、これらを考慮した値である。   From the viewpoint of suppressing the exposure of the negative electrode active material layer, it is considered that the electrode protective layer is denser, but the electrode protective layer requires a hole that allows passage of charge carriers and electrolyte. For this reason, there is an upper limit for the density of the electrode protective layer. In addition, when battery performance such as energy efficiency is taken into consideration, there is an upper limit for the basis weight of the electrode protective layer. The upper limit values of the density and basis weight of the electrode protective layer described above are values in consideration of these.

なお、ここで言う「電極保護層の密度」は、「電極保護層の空隙率」に換算できる。空隙率の大きい電極保護層は粗であり、空隙率の小さい電極保護層は密である。空隙率は、下式(1)によって算出可能である。なお、電極保護層の材料の真密度は、各材料の真密度と各材料の配合比とを基に算出可能である。
空隙率(%)={1−(電極保護層の密度/電極保護層の材料の真密度)}×100…(1)
電極保護層用のバインダは、蓄電装置の種類等に応じて適宜選択すれば良く、負極用の電極保護層に一般に用いられるバインダを使用すれば良い。例えば、ポリフッ化ビニリデン(PVdF)、フッ化ビニリデン−ヘキサフルオロプロピレン共重合体、ポリテトラフルオロエチレン(PTFE)、テトラフルオロエチレン−パーフルオロアルキルビニルエーテル共重合体、テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体、テトラフルオロエチレン−エチレン共重合体、ポリクロロトリフルオロエチレン等のフッ素系樹脂が挙げられる。或いは、アクリロニトリル−ブタジエン共重合体ゴム(NBR)、アクリロニトリル−イソプレン共重合体ゴム(NBIR)等のゴム系バインダを用いても良い。または、アクリル酸、メタクリル酸、アクリル酸エステル、メタクリル酸エステル等のアクリル系ポリマーを用いても良い。または、ポリ酢酸ビニル、エチレン−酢酸ビニル共重合体(EVA)等の酢酸ビニル系樹脂を用いても良い。バインダとしては、これらを単独で用いることもできるし、2種以上を併用することもできる。また、電極保護層は、絶縁性粒子およびバインダ以外の成分、例えば分散剤等の添加剤を含んでも良い。
The “density of the electrode protective layer” mentioned here can be converted into “the porosity of the electrode protective layer”. The electrode protective layer having a large porosity is rough, and the electrode protective layer having a small porosity is dense. The porosity can be calculated by the following formula (1). In addition, the true density of the material of the electrode protective layer can be calculated based on the true density of each material and the blending ratio of each material.
Porosity (%) = {1− (density of electrode protective layer / true density of material of electrode protective layer)} × 100 (1)
The binder for the electrode protective layer may be appropriately selected according to the type of the power storage device, and a binder generally used for the electrode protective layer for the negative electrode may be used. For example, polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer , Fluorine-based resins such as tetrafluoroethylene-ethylene copolymer and polychlorotrifluoroethylene. Alternatively, a rubber binder such as acrylonitrile-butadiene copolymer rubber (NBR) or acrylonitrile-isoprene copolymer rubber (NBIR) may be used. Alternatively, acrylic polymers such as acrylic acid, methacrylic acid, acrylic ester, and methacrylic ester may be used. Alternatively, a vinyl acetate resin such as polyvinyl acetate or ethylene-vinyl acetate copolymer (EVA) may be used. As the binder, these can be used alone or in combination of two or more. The electrode protective layer may contain components other than the insulating particles and the binder, for example, additives such as a dispersant.

電極保護層における絶縁性粒子およびバインダの量は、絶縁性粒子の種類、粒径、電極保護層の密度、電極保護層の目付量等に応じて適宜設定すれば良いが、範囲を設けるとすれば、電極保護層の質量を100質量%としたときに絶縁性粒子は90〜99質量%含まれるのが好ましく、95〜98質量%含まれるのがより好ましい。また、バインダは1質量%〜10質量%含まれるのが好ましく、2質量%〜5質量%含まれるのがより好ましい。   The amount of the insulating particles and the binder in the electrode protective layer may be appropriately set according to the kind of the insulating particles, the particle size, the density of the electrode protective layer, the basis weight of the electrode protective layer, etc. For example, when the mass of the electrode protective layer is 100% by mass, the insulating particles are preferably included in an amount of 90 to 99% by mass, and more preferably 95 to 98% by mass. Moreover, it is preferable that 1 mass%-10 mass% of binder is contained, and it is more preferable that 2 mass%-5 mass% are contained.

また、電極保護層の厚さは、電極保護層の密度および目付量に応じて必然的に決定される。具体的には、電極保護層の厚さは1μm〜15μmであるのが好ましく、2μm〜8μmであるのがより好ましい。   The thickness of the electrode protective layer is inevitably determined according to the density and basis weight of the electrode protective layer. Specifically, the thickness of the electrode protective layer is preferably 1 μm to 15 μm, and more preferably 2 μm to 8 μm.

〔蓄電装置〕
本発明の蓄電装置は、上記した本発明の負極を含むものである。本発明の蓄電装置は、例えば、非水電解質二次電池やリチウムイオンキャパシタ等として具現化できる。
[Power storage device]
The power storage device of the present invention includes the above-described negative electrode of the present invention. The power storage device of the present invention can be embodied as, for example, a nonaqueous electrolyte secondary battery or a lithium ion capacitor.

本発明の蓄電装置は、負極、正極および電解質を有し、必要に応じてセパレータを有する。本発明の蓄電装置における負極は電極保護層を持つため、電極保護層自体がセパレータとしての機能を持つ。このため、場合によってはセパレータを省略できる。また、例えば蓄電装置における電解質が固体電解質である場合やポリマー電解質である場合等、本発明の蓄電装置自体がセパレータを必要としない場合もある。   The power storage device of the present invention includes a negative electrode, a positive electrode, and an electrolyte, and a separator as necessary. Since the negative electrode in the power storage device of the present invention has an electrode protective layer, the electrode protective layer itself has a function as a separator. For this reason, a separator can be omitted depending on circumstances. In addition, for example, when the electrolyte in the power storage device is a solid electrolyte or a polymer electrolyte, the power storage device of the present invention itself may not require a separator.

正極は、電荷担体を吸蔵および放出し得る正極活物質を有する。正極は、集電体と、集電体の表面に設けた正極活物質層を有する。正極活物質層は正極活物質、ならびに必要に応じて結着剤および/または導電助剤を含む。正極の集電体は、使用する活物質に適した電圧に耐え得る金属であれば特に制限はなく、上記した負極と同様のものを使用すれば良い。正極のバインダおよび導電助剤に関しても、負極で説明したものと同様である。   The positive electrode has a positive electrode active material that can occlude and release charge carriers. The positive electrode has a current collector and a positive electrode active material layer provided on the surface of the current collector. The positive electrode active material layer includes a positive electrode active material and, if necessary, a binder and / or a conductive aid. The current collector of the positive electrode is not particularly limited as long as it is a metal that can withstand a voltage suitable for the active material to be used, and the same current collector as that described above may be used. The binder for the positive electrode and the conductive additive are the same as those described for the negative electrode.

正極活物質としては、例えば、層状化合物のLiNiCoMn(0.2≦a≦1.2、b+c+d+e=1、0≦e<1、DはLi、Fe、Cr、Cu、Zn、Ca、Mg、S、Si、Na、K、Al、Zr、Ti、P、Ga、Ge、V、Mo、Nb、W、Laから選ばれる少なくとも1の元素、1.7≦f≦2.1)、LiMnOを挙げることができる。また、正極活物質として、LiMn、LiMn等のスピネル、およびスピネルと層状化合物の混合物で構成される固溶体、LiMPO、LiMVOまたはLiMSiO(式中のMはCo、Ni、Mn、Feのうちの少なくとも一種から選択される)などで表されるポリアニオン系化合物を挙げることもできる。さらに、正極活物質として、LiFePOFなどのLiMPOF(Mは遷移金属)で表されるタボライト系化合物、LiFeBOなどのLiMBO(Mは遷移金属)で表されるボレート系化合物を挙げることもできる。正極活物質として用いられる何れの金属酸化物も上記の組成式を基本組成とすれば良く、基本組成に含まれる金属元素を他の金属元素で置換したものも使用可能である。また、正極活物質として、リチウム等の電荷担体を含まないもの、例えば、硫黄単体(S)、硫黄と炭素を複合化した化合物、TiSなどの金属硫化物、V、MnOなどの酸化物、ポリアニリンおよびアントラキノンならびにこれら芳香族を化学構造に含む化合物、共役二酢酸系有機物などの共役系材料、その他公知の材料を用いることもできる。さらに、ニトロキシド、ニトロニルニトロキシド、ガルビノキシル、フェノキシルなどの安定なラジカルを有する化合物を正極活物質として採用してもよい。上記したように電荷担体を含まない正極活物質を用いる場合には、正極および/または負極に、公知の方法により、予め電荷担体を添加しておくのが良い。なお、負極活物質層の表面に加え、正極活物質層の表面にも上記した電極保護層を設けても良い。この場合、正極活物質層の表面粗さRaを、上記した負極活物質層の表面粗さRaと同様に、0.1μm以上10μm以下にするのが良く、0.1μm以上2.0μm以下にするのがより好ましく、0.1μm以上1.0μm以下にするのがさらに好ましい。
また、電極保護層は、上記した負極の電極保護層と同様に、絶縁性粒子とバインダとで構成し、その密度が1.45g/cm以上4g/cm未満となるようにし、さらにその目付量が0.5mg/cm以上2.0mg/cm以下となるようにするのが良い。
As the positive electrode active material, for example, a layered compound Li a Ni b Co c Mn d De O f (0.2 ≦ a ≦ 1.2, b + c + d + e = 1, 0 ≦ e <1, D is Li, Fe, At least one element selected from Cr, Cu, Zn, Ca, Mg, S, Si, Na, K, Al, Zr, Ti, P, Ga, Ge, V, Mo, Nb, W, La, 1.7 ≦ f ≦ 2.1) and Li 2 MnO 3 . Further, as a positive electrode active material, a solid solution composed of a spinel such as LiMn 2 O 4 and Li 2 Mn 2 O 4 and a mixture of a spinel and a layered compound, LiMPO 4 , LiMVO 4 or Li 2 MSiO 4 (M in the formula) May be selected from at least one of Co, Ni, Mn, and Fe). Furthermore, as the positive electrode active material, tavorite compound (the M a transition metal) LiMPO 4 F, such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal) include borate-based compound represented by You can also Any metal oxide used as the positive electrode active material may have the above composition formula as a basic composition, and a metal element contained in the basic composition may be substituted with another metal element. In addition, the positive electrode active material does not include a charge carrier such as lithium, for example, sulfur alone (S), a compound in which sulfur and carbon are combined, metal sulfide such as TiS 2 , V 2 O 5 , MnO 2, etc. These oxides, polyaniline and anthraquinone, compounds containing these aromatics in the chemical structure, conjugated materials such as conjugated diacetate-based organic substances, and other known materials can also be used. Further, a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl, etc. may be adopted as the positive electrode active material. As described above, when using a positive electrode active material that does not include a charge carrier, it is preferable to add a charge carrier to the positive electrode and / or the negative electrode in advance by a known method. In addition to the surface of the negative electrode active material layer, the above-described electrode protective layer may be provided on the surface of the positive electrode active material layer. In this case, the surface roughness Ra of the positive electrode active material layer is preferably 0.1 μm or more and 10 μm or less, similar to the surface roughness Ra of the negative electrode active material layer described above, and is 0.1 μm or more and 2.0 μm or less. More preferably, it is more preferably 0.1 μm or more and 1.0 μm or less.
The electrode protective layer is composed of insulating particles and a binder in the same manner as the electrode protective layer of the negative electrode described above, and its density is 1.45 g / cm 3 or more and less than 4 g / cm 3 , and The basis weight is preferably 0.5 mg / cm 2 or more and 2.0 mg / cm 2 or less.

電解質は、蓄電装置の種類に応じたものを用いれば良く、特に限定されない。例えば、本発明の蓄電装置が非水電解質二次電池であれば、電解質として、有機溶媒に支持塩(支持電解質とも言う)を溶解させたものを用いれば良い。例えば蓄電装置がリチウムイオン二次電池の場合には、有機溶媒として、非プロトン性有機溶媒、例えばプロピレンカーボネート(PC)、エチレンカーボネート(EC)、ジメチルカーボネート(DMC)、ジエチルカーボネート(DEC)、エチルメチルカーボネート(EMC)等から選ばれる少なくとも一種を好ましく選択できる。また、この場合の支持塩としては、有機溶媒に可溶なリチウム金属塩を用いるのが良く、例えば、LiPF、LiBF、LIASF、LiI、LiClO、LiCFSOからなる群から選ばれる少なくとも一種を用いるのが好適である。支持塩は、有機溶媒に0.5mol/l〜1.7mol/l程度の濃度で溶解させるのが好ましい。 The electrolyte is not particularly limited as long as the electrolyte corresponds to the type of power storage device. For example, if the power storage device of the present invention is a nonaqueous electrolyte secondary battery, an electrolyte in which a supporting salt (also referred to as a supporting electrolyte) is dissolved in an organic solvent may be used. For example, when the power storage device is a lithium ion secondary battery, the organic solvent is an aprotic organic solvent such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl At least one selected from methyl carbonate (EMC) and the like can be preferably selected. In this case, the supporting salt is preferably a lithium metal salt that is soluble in an organic solvent. For example, the supporting salt is selected from the group consisting of LiPF 6 , LiBF 4 , LIASF 6 , LiI, LiClO 4 , LiCF 3 SO 3. It is preferable to use at least one kind. The supporting salt is preferably dissolved in the organic solvent at a concentration of about 0.5 mol / l to 1.7 mol / l.

蓄電装置には必要に応じてセパレータが用いられる。セパレータは、負極と正極とを隔離し、両極の接触による電流の短絡を防止しつつ、電解液および電荷担体の通過を許容するものである。セパレータとしては、ポリテトラフルオロエチレン、ポリプロピレン、ポリエチレン、ポリイミド、ポリアミド、ポリアラミド(Aromatic polyamide)、ポリエステル、ポリアクリロニトリル等の合成樹脂、セルロース、アミロース等の多糖類、フィブロイン、ケラチン、リグニン、スベリン等の天然高分子、セラミックスなどの電気絶縁性材料を1種または複数種用いた多孔体、不織布、織布などを挙げることができる。また、セパレータは多層構造としても良い。   A separator is used in the power storage device as necessary. The separator separates the negative electrode from the positive electrode, and allows passage of the electrolyte and the charge carrier while preventing a short circuit of current due to contact between the two electrodes. As separators, natural resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polymer), polyester, polyacrylonitrile and other polysaccharides, cellulose, amylose and other polysaccharides, fibroin, keratin, lignin and suberin Examples thereof include porous bodies, nonwoven fabrics, and woven fabrics using one or more kinds of electrically insulating materials such as polymers and ceramics. The separator may have a multilayer structure.

上述した負極および正極に、必要に応じてセパレータを挟装させ電極体とする。電極体は、負極、セパレータおよび正極を重ねた積層型、または、負極、セパレータおよび正極を捲いた捲回型の何れの型にしても良い。負極の集電体および正極の集電体から外部に通ずる負極端子および正極端子までの間を、集電用リード等を用いて接続した後に、電極体に電解質を加えることで蓄電装置を得ることが可能である。   A separator is sandwiched between the negative electrode and the positive electrode as described above to form an electrode body. The electrode body may be any of a laminated type in which a negative electrode, a separator and a positive electrode are stacked, or a wound type in which a negative electrode, a separator and a positive electrode are sandwiched. After connecting the negative electrode current collector and the positive electrode current collector to the negative electrode terminal and the positive electrode terminal connected to the outside using a current collecting lead or the like, an electric storage device is obtained by adding an electrolyte to the electrode body Is possible.

本発明の蓄電装置の形状は特に限定されるものでなく、円筒型、角型、コイン型、ラミネート型等、種々の形状を採用することができる。   The shape of the power storage device of the present invention is not particularly limited, and various shapes such as a cylindrical shape, a square shape, a coin shape, and a laminate shape can be employed.

本発明の蓄電装置の用途は特に限定されず、パーソナルコンピュータ、携帯通信機器など、電力で駆動される各種の家電製品、オフィス機器、産業機器、車両等が挙げられる。   The application of the power storage device of the present invention is not particularly limited, and examples thereof include various home electric appliances driven by electric power, such as personal computers and portable communication devices, office equipment, industrial equipment, and vehicles.

以下に、実施例および比較例を基に、本発明を具体的に説明する。なお、本発明は以下の実施例および比較例によって限定されるものではない。以下において、特に断らない限り、「部」とは質量部を意味し、「%」とは質量%を意味する。   The present invention will be specifically described below based on examples and comparative examples. The present invention is not limited to the following examples and comparative examples. In the following, unless otherwise specified, “part” means part by mass, and “%” means mass%.

(試験1)
試験1の負極およびその製造方法を以下に説明する。
(Test 1)
The negative electrode of Test 1 and the manufacturing method thereof will be described below.

〔負極活物質層形成工程〕
負極活物質としては平均粒径20μmの黒鉛を用いた。黒鉛と、バインダとしてのスチレン・ブタジエンゴム(SBR)と、バインダとしてのカルボキシメチルセルロース(CMC)とを、黒鉛:SBR:CMC=98:1:1の質量比で混合し、溶媒を加えてスラリー状をなす負極合材を得た。溶媒としてはN‐メチル‐2‐ピロリドン(NMP)を用いた。
[Negative electrode active material layer forming step]
As the negative electrode active material, graphite having an average particle size of 20 μm was used. Graphite, styrene-butadiene rubber (SBR) as a binder, and carboxymethyl cellulose (CMC) as a binder are mixed at a mass ratio of graphite: SBR: CMC = 98: 1: 1, and a solvent is added to form a slurry. A negative electrode composite material was obtained. N-methyl-2-pyrrolidone (NMP) was used as the solvent.

次いで、上記のスラリー状の負極合材を、ドクターブレードを用いて集電体の片面に塗布した。集電体としては厚さ20μmの銅箔を用いた。このときの負極合材の目付量は11mg/cmであった。集電体および負極合材を120℃で1分間乾燥した後にプレス機によりプレスした。以上の工程により、集電体上に負極活物質層を形成した。負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。 Next, the slurry-like negative electrode mixture was applied to one side of the current collector using a doctor blade. A copper foil having a thickness of 20 μm was used as the current collector. The basis weight of the negative electrode mixture at this time was 11 mg / cm 2 . The current collector and the negative electrode mixture were dried at 120 ° C. for 1 minute and then pressed with a press. Through the above steps, a negative electrode active material layer was formed on the current collector. The density of the negative electrode active material layer was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm.

〔電極保護層形成工程〕
絶縁性粒子としては、平均粒径0.5μmのアルミナを用い、バインダとしてはポリフッ化ビニリデン(PVdF)を用いた。アルミナとPVdFとを、アルミナ:PVdF=96:4の質量比で混合し、溶媒を加えてスラリー状をなす電極保護層合材を得た。溶媒としてはNMPを用いた。溶媒の量は、アルミナとPVdFとの混合物35質量部に対して65質量部であった。
[Electrode protective layer forming step]
As the insulating particles, alumina having an average particle diameter of 0.5 μm was used, and as the binder, polyvinylidene fluoride (PVdF) was used. Alumina and PVdF were mixed at a mass ratio of alumina: PVdF = 96: 4, and a solvent was added to obtain a slurry-like electrode protective layer mixture. NMP was used as the solvent. The amount of the solvent was 65 parts by mass with respect to 35 parts by mass of the mixture of alumina and PVdF.

次いで、上記のスラリー状の電極保護層合材を、ダイコータを用いて負極活物質層上に塗布した。その後110℃で1分間温風乾燥することで、電極保護層を形成した。この電極保護層の目付量は0.19mg/cmであった。この電極保護層の厚さは1.25μmであり、密度は1.50g/cmであった。電極保護層の目付量は蛍光X線分析法で測定した。電極保護層の厚さは、電極保護層形成後の負極活物質層と電極保護層との厚さの和から、電極保護層形成前の負極活物質層の厚さを引いた値である。なお、ここでいう電極保護層の厚さとは、マイクロメータでランダムに5点計測した値の平均値である。電極保護層の密度は、電極保護層の目付量と電極保護層の厚さから換算可能であり、具体的には目付量を厚さで除した値である。 Next, the slurry-like electrode protective layer mixture was applied onto the negative electrode active material layer using a die coater. Thereafter, the electrode protective layer was formed by drying with hot air at 110 ° C. for 1 minute. The basis weight of this electrode protective layer was 0.19 mg / cm 2 . This electrode protective layer had a thickness of 1.25 μm and a density of 1.50 g / cm 3 . The basis weight of the electrode protective layer was measured by fluorescent X-ray analysis. The thickness of the electrode protective layer is a value obtained by subtracting the thickness of the negative electrode active material layer before forming the electrode protective layer from the sum of the thicknesses of the negative electrode active material layer and the electrode protective layer after forming the electrode protective layer. In addition, the thickness of the electrode protective layer here is an average value of values obtained by randomly measuring five points with a micrometer. The density of the electrode protective layer can be converted from the basis weight of the electrode protective layer and the thickness of the electrode protective layer, and is specifically a value obtained by dividing the basis weight by the thickness.

さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は、{1−(1.50/4)}×100=62.5(%)であった。なお、材料の真密度として絶縁粒子の真密度(4g/m)を用いた。試験1の電極保護層におけるバインダの含量は4質量%であり、無視できる程度に少なかった。 Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was {1− (1.50 / 4)} × 100 = 62.5 (%). Note that the true density of insulating particles (4 g / m 3 ) was used as the true density of the material. The binder content in the electrode protective layer of Test 1 was 4% by mass, which was negligibly small.

以上の工程で集電体上に負極活物質層および電極保護層が設けられてなる積層体を得た。この積層体を所定の形状に切り取って試験1の負極を得た。   Through the above steps, a laminate in which the negative electrode active material layer and the electrode protective layer were provided on the current collector was obtained. This laminate was cut into a predetermined shape to obtain a negative electrode for Test 1.

(試験2)
試験2の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験2の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.38mg/cmであった。この電極保護層の厚さは2.5μmであり、密度は1.50g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は62.5%であった。
(Test 2)
The negative electrode of Test 2 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 2 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.38 mg / cm 2 . This electrode protective layer had a thickness of 2.5 μm and a density of 1.50 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 62.5%.

試験2の負極の製造方法は、ダイコータのギャップ、つまり、スラリー状の電極保護層合材が吐出されるダイコータの隙間が大きかった点で試験1の負極の製造方法と異なる。ダイコータのギャップが大きければ、電極保護層の目付量が多くなる。   The negative electrode manufacturing method of Test 2 is different from the negative electrode manufacturing method of Test 1 in that the gap of the die coater, that is, the gap of the die coater from which the slurry-like electrode protective layer composite material is discharged is large. If the gap of the die coater is large, the basis weight of the electrode protective layer increases.

(試験3)
試験3の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験3の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.60mg/cmであった。この電極保護層の厚さは4.0μmであり、密度は1.50g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は62.5%であった。
(Test 3)
The negative electrode of Test 3 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 3 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.60 mg / cm 2 . This electrode protective layer had a thickness of 4.0 μm and a density of 1.50 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 62.5%.

試験3の負極の製造方法は、試験2の負極の製造方法と同様に、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method of Test 3 is different from the negative electrode manufacturing method of Test 1 in that the gap of the die coater is large, similarly to the negative electrode manufacturing method of Test 2.

(試験4)
試験4の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験4の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.83mg/cmであった。この電極保護層の厚さは5.5μmであり、密度は1.50g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は62.5%であった。
(Test 4)
The negative electrode of Test 4 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 4 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.83 mg / cm 2 . This electrode protective layer had a thickness of 5.5 μm and a density of 1.50 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 62.5%.

試験4の負極の製造方法は、試験2のおよび試験3の負極の製造方法と同様に、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method in Test 4 is different from the negative electrode manufacturing method in Test 1 in that the gap of the die coater is large, as in the negative electrode manufacturing method in Test 2 and Test 3.

(試験5)
試験5の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験5の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.76mg/cmであった。この電極保護層の厚さは4.5μmであり、密度は1.68g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は58.0%であった。
(Test 5)
The negative electrode of Test 5 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 5 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.76 mg / cm 2 . This electrode protective layer had a thickness of 4.5 μm and a density of 1.68 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 58.0%.

試験5の負極の製造方法は、電極保護層合材における固形分(つまりアルミナとPVdFの含有量)が多かった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。試験1における電極保護層合材はアルミナとPVdFとの混合物を35質量部含んでいたのに対し、試験5における電極保護層合材はアルミナとPVdFとの混合物を37質量部含んでいた。   The negative electrode manufacturing method of Test 5 is different from the negative electrode manufacturing method of Test 1 in that the solid content (that is, the content of alumina and PVdF) in the electrode protective layer mixture was large and the gap of the die coater was large. . The electrode protective layer mixture in Test 1 contained 35 parts by mass of a mixture of alumina and PVdF, whereas the electrode protective layer mixture in Test 5 contained 37 parts by mass of a mixture of alumina and PVdF.

(試験6)
試験6の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験6の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.61mg/cmであった。この電極保護層の厚さは3.65μmであり、密度は1.68g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は58.0%であった。
(Test 6)
The negative electrode of Test 6 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 6 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.61 mg / cm 2 . This electrode protective layer had a thickness of 3.65 μm and a density of 1.68 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 58.0%.

試験6の負極の製造方法は、試験5の負極の製造方法と同様に、電極保護層合材における固形分が多かった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method of Test 6 is the same as the negative electrode manufacturing method of Test 5, and the negative electrode manufacturing method of Test 1 in that the solid content in the electrode protective layer mixture was large and the gap of the die coater was large. And different.

(試験7)
試験7の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験7の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.34mg/cmであった。この電極保護層の厚さは2.0μmであり、密度は1.68g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は58.0%であった。
(Test 7)
The negative electrode of Test 7 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 7 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.34 mg / cm 2 . This electrode protective layer had a thickness of 2.0 μm and a density of 1.68 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 58.0%.

試験7の負極の製造方法は、試験5および試験6の負極の製造方法と同様に、電極保護層合材における固形分が多かった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method in Test 7 was the same as the negative electrode manufacturing method in Test 5 and Test 6, in that the solid content in the electrode protective layer mixture was large and the gap in the die coater was large. Different from the manufacturing method.

(試験8)
試験8の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験8の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.83mg/cmであった。この電極保護層の厚さは6.0μmであり、密度は1.39g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は65.25%であった。
(Test 8)
The negative electrode of Test 8 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 8 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.83 mg / cm 2 . This electrode protective layer had a thickness of 6.0 μm and a density of 1.39 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 65.25%.

試験8の負極の製造方法は、電極保護層合材における固形分が少なかった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。試験1における電極保護層合材はアルミナとPVdFとの混合物を35質量部含んでいたのに対し、試験8における電極保護層合材はアルミナとPVdFとの混合物を33質量部含んでいた。   The negative electrode manufacturing method of Test 8 differs from the negative electrode manufacturing method of Test 1 in that the solid content in the electrode protective layer mixture was small and the gap of the die coater was large. The electrode protective layer mixture in Test 1 contained 35 parts by mass of a mixture of alumina and PVdF, whereas the electrode protective layer mixture in Test 8 contained 33 parts by mass of a mixture of alumina and PVdF.

(試験9)
試験9の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験9の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.60mg/cmであった。この電極保護層の厚さは4.3μmであり、密度は1.39g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は65.25%であった。
(Test 9)
The negative electrode of Test 9 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 9 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.60 mg / cm 2 . This electrode protective layer had a thickness of 4.3 μm and a density of 1.39 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 65.25%.

試験9の負極の製造方法は、試験8の負極の製造方法と同様に、電極保護層合材における固形分が少なかった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method of Test 9 is similar to the negative electrode manufacturing method of Test 8 in that the solid content in the electrode protective layer mixture is small and the gap of the die coater is large. And different.

(試験10)
試験10の負極は、電極保護層の目付量、膜厚、密度および空隙率以外は試験1の負極と同じものである。試験10の負極における負極活物質層の密度は1.4g/cmであり、負極活物質層の表面粗さは0.8μmであった。また、電極保護層の目付量は0.42mg/cmであった。この電極保護層の厚さは3.0μmであり、密度は1.39g/cmであった。さらに、上記換算式(1)に基づいて計算した電極保護層の空隙率は65.25%であった。
(Test 10)
The negative electrode of Test 10 is the same as the negative electrode of Test 1 except for the basis weight, film thickness, density, and porosity of the electrode protective layer. The density of the negative electrode active material layer in the negative electrode of Test 10 was 1.4 g / cm 3 , and the surface roughness of the negative electrode active material layer was 0.8 μm. The basis weight of the electrode protective layer was 0.42 mg / cm 2 . This electrode protective layer had a thickness of 3.0 μm and a density of 1.39 g / cm 3 . Furthermore, the porosity of the electrode protective layer calculated based on the conversion formula (1) was 65.25%.

試験10の負極の製造方法は、試験8および試験9の負極の製造方法と同様に、電極保護層合材における固形分が少なかった点、および、ダイコータのギャップが大きかった点で試験1の負極の製造方法と異なる。   The negative electrode manufacturing method in Test 10 was the same as the negative electrode manufacturing method in Test 8 and Test 9, in that the solid content in the electrode protective layer mixture was small and the gap in the die coater was large. Different from the manufacturing method.

<評価試験>
試験1〜試験10の各負極の表面をSEMで観察することで、負極表面に負極活物質が露出しているか否かを評価した。400倍のSEM像を目視で観察し、縦横ともに数十μmにわたって負極活物質層が露出しているものを、負極活物質層の露出あり(×)と評価した。具体的には、負極活物質層が縦横ともに20μm以上にわたって露出しているものを×と評価した。また、負極活物質の露出がこれ以下のものを負極活物質層の露出なし(○)と評価した。評価試験の結果を表1に示す。また試験1の負極の表面のSEM像を図3に示し、試験4の負極の表面のSEM像を図4に示す。図3および図4のSEM像は何れも拡大率1000倍である。さらに、電極保護層の目付量、膜厚および密度と、評価試験の結果との関係を表すグラフを図5に示す。なお、図5中直線(I)は、電極保護層の密度が4g/cmである場合(つまり、電極保護層が絶縁性粒子たるアルミナのみで構成されかつ空隙率が0%である場合)を想定した、電極保護層の目付量と膜厚との関係を表す直線である。さらに、図5中直線(II)は、電極保護層が絶縁性粒子たるアルミナおよびバインダたるPVdFで構成され、電極保護層の真密度が3.91g/cmであり、電極保護層の空隙率が0%である場合を想定した、電極保護層の目付量と膜厚との関係を表す直線である。この場合アルミナとPVdFとの配合比は、質量比でアルミナ:PVdF=96:4であると想定される。
<Evaluation test>
By observing the surface of each negative electrode of Test 1 to Test 10 with SEM, it was evaluated whether or not the negative electrode active material was exposed on the negative electrode surface. A 400-times magnification SEM image was visually observed, and the negative electrode active material layer exposed over several tens of micrometers both vertically and horizontally was evaluated as having an exposed negative electrode active material layer (x). Specifically, the case where the negative electrode active material layer was exposed over 20 μm or more both vertically and horizontally was evaluated as x. Moreover, the negative electrode active material exposure was evaluated as “no exposure (◯)” of the negative electrode active material layer. The results of the evaluation test are shown in Table 1. Moreover, the SEM image of the surface of the negative electrode of Test 1 is shown in FIG. 3, and the SEM image of the surface of the negative electrode of Test 4 is shown in FIG. Each of the SEM images in FIGS. 3 and 4 has a magnification of 1000 times. Furthermore, the graph showing the relationship between the basis weight of an electrode protective layer, a film thickness, and a density and the result of an evaluation test is shown in FIG. Note that the straight line (I) in FIG. 5 is when the density of the electrode protective layer is 4 g / cm 3 (that is, when the electrode protective layer is composed only of alumina as insulating particles and the porosity is 0%). Is a straight line representing the relationship between the basis weight of the electrode protective layer and the film thickness. Further, the straight line (II) in FIG. 5 shows that the electrode protective layer is composed of alumina as insulating particles and PVdF as a binder, the true density of the electrode protective layer is 3.91 g / cm 3 , and the porosity of the electrode protective layer This is a straight line representing the relationship between the weight per unit area of the electrode protective layer and the film thickness, assuming that 0 is 0%. In this case, the mixing ratio of alumina and PVdF is assumed to be alumina: PVdF = 96: 4 by mass ratio.

本発明の負極は、下記の(a)〜(c)の全てを満たす。
(a)電極保護層の密度が1.45g/cm以上4g/cm未満、
(b)電極保護層の目付量が0.5mg/cm以上2.0mg/cm以下、
(c)負極活物質層の表面粗さRaが0.1μm以上10μm以下。
The negative electrode of the present invention satisfies all of the following (a) to (c).
(A) The density of the electrode protective layer is 1.45 g / cm 3 or more and less than 4 g / cm 3 ,
(B) The basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2 or less,
(C) The surface roughness Ra of the negative electrode active material layer is 0.1 μm or more and 10 μm or less.

また、図5中斜線で表した領域は、(a)および(b)を満たす領域であり、試験1〜試験10の負極における負極活物質層の表面粗さRaは何れも(c)を満たす。   Moreover, the area | region represented with the oblique line in FIG. 5 is an area | region which satisfy | fills (a) and (b), and all the surface roughness Ra of the negative electrode active material layer in the negative electrode of Test 1-Test 10 satisfy | fills (c). .

表1、図3および図5に示すように、(a)または(b)を満たさない試験1、2、7〜10の負極の表面には、負極活物質層の露出がみられた。これに対し、表1、図4および図5に示すように、(a)〜(c)の全てを満たす試験3〜試験6の負極の表面には負極活物質層の露出はみられなかった。このことから、(a)〜(c)の全てを満たすことで、負極の表面における負極活物質層の露出を抑制できるといえる。   As shown in Table 1, FIG. 3, and FIG. 5, the negative electrode active material layer was exposed on the surface of the negative electrode in Tests 1, 2, and 7 to 10 that did not satisfy (a) or (b). On the other hand, as shown in Table 1, FIG. 4, and FIG. 5, the negative electrode active material layer was not exposed on the surface of the negative electrode of Test 3 to Test 6 that satisfied all of (a) to (c). . From this, it can be said that the exposure of the negative electrode active material layer on the surface of the negative electrode can be suppressed by satisfying all of (a) to (c).

また、図5に示すように、電極保護層の目付量は0.5mg/cm以上であれば良いが、0.55mg/cm以上であるのが好ましく、0.6mg/cm以上であるのがより好ましい。同様に、図5を基にすると、電極保護層の密度は1.45g/cm以上であれば良いが、1.50g/cm以上であるのが特に好ましい。また、図5中(II)を考慮すると、電極保護層の密度は3.91g/cm以下であるのが好ましい。 In addition, as shown in FIG. 5, the basis weight of the electrode protective layer may be at 0.5 mg / cm 3 or more, but preferably at 0.55 mg / cm 3 or more, 0.6 mg / cm 3 or more More preferably. Similarly, on the basis of FIG. 5, the density of the electrode protection layer may if 1.45 g / cm 3 or more, and particularly preferably 1.50 g / cm 3 or more. In consideration of (II) in FIG. 5, the density of the electrode protective layer is preferably 3.91 g / cm 3 or less.

参考までに、上記(a)は下記(a2)と言い換えることができる。
(a2)電極保護層の空隙率が0%を超え63.75%以下。
For reference, the above (a) can be restated as the following (a2).
(A2) The porosity of the electrode protective layer is more than 0% and not more than 63.75%.

また、電極保護層の空隙率は62.5%以下であるのが特に好ましいといえ、さらに、図5中(II)を考慮すると61.6%以上であるのが好ましいといえる。   Further, it can be said that the porosity of the electrode protective layer is particularly preferably 62.5% or less, and further, it is preferable that the porosity is 61.6% or more considering (II) in FIG.

なお、負極活物質層の表面粗さが0.8μmである試験3〜6の負極において負極活物質層の露出評価が○であったため、負極活物質層の表面粗さRaが0.8μmよりも大きい場合にも負極活物質層の露出を抑制できる蓋然性が高い。例えば試験3の負極における電極保護層の目付量は0.6mg/cmであり、電極保護層の目付量の最大値2.0mg/cmに比べると遙かに少ないにも拘わらず負極活物質層の露出抑制を実現している。したがって、電極保護層の目付量を最大値に近づければ、負極活物質層の表面粗さRaがさらに大きい場合、例えば10μmである場合にも、負極活物質層の露出を抑制できる蓋然性が高い。これに加えて、電極保護層の密度を最大値である4g/cm付近まで高めることで、負極活物質層の露出をさらに抑制できる。本発明の負極における負極活物質層の表面粗さRaの上限値はこれを鑑みて決定した値である。なお、好ましくは、負極活物質層の表面粗さRaは5.0μm以下であるのが良く、さらに好ましくは2.0μm以下であるのが良く、特に好ましくは1.0μm以下であるのが良い。 In addition, in the negative electrodes of Tests 3 to 6 in which the surface roughness of the negative electrode active material layer was 0.8 μm, the negative electrode active material layer exposure evaluation was ○, and thus the surface roughness Ra of the negative electrode active material layer was 0.8 μm or less. The probability that the exposure of the negative electrode active material layer can be suppressed is also high. For example, the basis weight of the electrode protective layer in the negative electrode of Test 3 is 0.6 mg / cm 2, which is much less than the maximum value of the electrode protective layer basis weight of 2.0 mg / cm 2. The exposure of the material layer is suppressed. Therefore, if the basis weight of the electrode protective layer is close to the maximum value, the probability that the exposure of the negative electrode active material layer can be suppressed even when the surface roughness Ra of the negative electrode active material layer is larger, for example, 10 μm, is high. . In addition to this, exposure of the negative electrode active material layer can be further suppressed by increasing the density of the electrode protective layer to the vicinity of the maximum value of 4 g / cm 3 . The upper limit value of the surface roughness Ra of the negative electrode active material layer in the negative electrode of the present invention is a value determined in view of this. Preferably, the surface roughness Ra of the negative electrode active material layer is 5.0 μm or less, more preferably 2.0 μm or less, and particularly preferably 1.0 μm or less. .

〔その他〕
各試験の負極を用い、リチウムイオン二次電池を製作した。正極としては、LiNi5/10Co2/10Mn3/10で表される層状岩塩構造のリチウム含有金属酸化物を用いた。
[Others]
A lithium ion secondary battery was manufactured using the negative electrode of each test. As the positive electrode, a lithium-containing metal oxide having a layered rock salt structure represented by LiNi 5/10 Co 2/10 Mn 3/10 O 2 was used.

電解質用の有機溶媒としては、エチレンカーボネート(EC):メチルエチルカーボネート(MEC):ジメチルカーボネート(DMC)=3:3:4(体積比)の混合溶液を用いた。支持塩としてはLiPFを用いた。支持塩を有機溶媒に1モル/Lとなるように溶解させて液状の電解質(電解液)を得た。 As the organic solvent for the electrolyte, a mixed solution of ethylene carbonate (EC): methyl ethyl carbonate (MEC): dimethyl carbonate (DMC) = 3: 3: 4 (volume ratio) was used. LiPF 6 was used as the supporting salt. The supporting salt was dissolved in an organic solvent so as to be 1 mol / L to obtain a liquid electrolyte (electrolytic solution).

上記の正極および負極の間に、セパレータとしてポリエチレン(PE)製の矩形状シート(厚さ25μm)を挟装して極板群とした。この極板群を二枚一組のラミネートフィルムで覆い、三辺をシールした後、袋状となったラミネートフィルムに上記電解液を注入した。その後、残りの一辺をシールすることで、四辺が気密にシールされ、極板群および電解液が密閉されたラミネート型リチウムイオン二次電池を得た。なお、正極および負極は外部と電気的に接続可能なタブを備え、このタブの一部はラミネート型リチウムイオン二次電池の外側に延出したものである。このように製作された各リチウムイオン二次電池を充放電すると、負極表面に負極活物質層が露出したものに関しては負極表面にリチウムの析出がみられ、負極表面に負極活物質層が露出していないものに関してはリチウムの析出はみられなかった。   Between the positive electrode and the negative electrode, a rectangular sheet (thickness 25 μm) made of polyethylene (PE) was sandwiched as a separator to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution was poured into the bag-like laminated film. Thereafter, the remaining one side was sealed to obtain a laminate type lithium ion secondary battery in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed. The positive electrode and the negative electrode have a tab that can be electrically connected to the outside, and a part of the tab extends to the outside of the laminated lithium ion secondary battery. When charging / discharging each lithium ion secondary battery manufactured in this manner, lithium deposition was observed on the negative electrode surface, and the negative electrode active material layer was exposed on the negative electrode surface for the negative electrode active material layer exposed on the negative electrode surface. No lithium deposition was observed for those not.

Claims (4)

集電体と、前記集電体上に設けられている負極活物質層と、前記負極活物質層上に設けられている電極保護層と、を含み、
前記電極保護層は、絶縁性粒子とバインダとを含み、
前記電極保護層の密度は1.45g/cm以上4g/cm未満であり、
前記電極保護層の目付量は0.5mg/cm以上2.0mg/cm以下であり、
前記負極活物質層の表面粗さRaは0.1μm以上10μm以下である負極。
A current collector, a negative electrode active material layer provided on the current collector, and an electrode protective layer provided on the negative electrode active material layer,
The electrode protective layer includes insulating particles and a binder,
The electrode protective layer has a density of 1.45 g / cm 3 or more and less than 4 g / cm 3 ;
The basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2 or less,
The negative electrode active material layer has a surface roughness Ra of 0.1 μm or more and 10 μm or less.
前記負極活物質層の表面粗さRaは0.1μm以上2.0μm以下である請求項1に記載の負極。   The negative electrode according to claim 1, wherein the negative electrode active material layer has a surface roughness Ra of 0.1 μm or more and 2.0 μm or less. 請求項1または請求項2に記載の負極を含む蓄電装置。   A power storage device comprising the negative electrode according to claim 1. 負極活物質を含む負極活物質層を集電体上に形成する負極活物質層形成工程と、
絶縁性粒子およびバインダを含む電極保護層を前記負極活物質層上に形成する電極保護層形成工程と、を含み、
前記負極活物質層形成工程において、前記負極活物質層の表面粗さを0.1μm以上10μm以下にし、
前記電極保護層形成工程において、前記電極保護層の密度を1.45g/cm以上4g/cm未満にし、前記電極保護層の目付量を0.5mg/cm以上2.0mg/cm以下にする負極の製造方法。
A negative electrode active material layer forming step of forming a negative electrode active material layer containing a negative electrode active material on a current collector;
An electrode protective layer forming step of forming an electrode protective layer containing insulating particles and a binder on the negative electrode active material layer, and
In the negative electrode active material layer forming step, the surface roughness of the negative electrode active material layer is 0.1 μm or more and 10 μm or less,
In the electrode protective layer forming step, the density of the electrode protective layer is 1.45 g / cm 3 or more and less than 4 g / cm 3 , and the basis weight of the electrode protective layer is 0.5 mg / cm 2 or more and 2.0 mg / cm 2. The manufacturing method of the negative electrode made below.
JP2014055000A 2014-03-18 2014-03-18 Negative electrode, method of manufacturing the same, and power storage device Pending JP2015176856A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2014055000A JP2015176856A (en) 2014-03-18 2014-03-18 Negative electrode, method of manufacturing the same, and power storage device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2014055000A JP2015176856A (en) 2014-03-18 2014-03-18 Negative electrode, method of manufacturing the same, and power storage device

Publications (1)

Publication Number Publication Date
JP2015176856A true JP2015176856A (en) 2015-10-05

Family

ID=54255844

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2014055000A Pending JP2015176856A (en) 2014-03-18 2014-03-18 Negative electrode, method of manufacturing the same, and power storage device

Country Status (1)

Country Link
JP (1) JP2015176856A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108630893A (en) * 2017-03-23 2018-10-09 株式会社东芝 Electrode complex, secondary cell, battery pack and vehicle
CN111490229A (en) * 2019-01-25 2020-08-04 株式会社理光 Electrode and its manufacturing method, electrode element, electrochemical element
JP2020119887A (en) * 2019-01-25 2020-08-06 株式会社リコー Electrode and manufacturing method thereof, electrode element, and electrochemical element
CN111937189A (en) * 2018-02-06 2020-11-13 积水化学工业株式会社 Electrode for lithium ion secondary battery, method for producing same, and lithium ion secondary battery
WO2023065927A1 (en) * 2021-10-18 2023-04-27 宁德时代新能源科技股份有限公司 Pole piece, assembly, cell, battery, device, and pole piece manufacturing method and system
CN116589892A (en) * 2022-02-14 2023-08-15 朴力美电动车辆活力株式会社 Method for producing slurry for insulating protective layer of secondary battery and apparatus for producing slurry for insulating protective layer of secondary battery

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005098997A1 (en) * 2004-03-30 2005-10-20 Matsushita Electric Industrial Co., Ltd. Nonaqueous electrolyte secondary battery
JP2006139978A (en) * 2004-11-11 2006-06-01 Hitachi Maxell Ltd Nonaqueous battery and method for manufacturing same
JP2009032668A (en) * 2007-06-22 2009-02-12 Panasonic Corp Nonaqueous secondary battery, battery pack, power source system, and electrically powered equipment
JP2009301765A (en) * 2008-06-11 2009-12-24 Sony Corp Electrode with porous protective membrane, nonaqueous electrolyte secondary battery, and method of manufacturing electrode with porous protective membrane
JP2010061912A (en) * 2008-09-02 2010-03-18 Tdk Corp Method for manufacturing electrode, and electrode
JP2014032758A (en) * 2012-08-01 2014-02-20 Nippon Zeon Co Ltd Method of manufacturing electrode for lithium ion secondary battery, and lithium ion secondary battery

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005098997A1 (en) * 2004-03-30 2005-10-20 Matsushita Electric Industrial Co., Ltd. Nonaqueous electrolyte secondary battery
JP2006139978A (en) * 2004-11-11 2006-06-01 Hitachi Maxell Ltd Nonaqueous battery and method for manufacturing same
JP2009032668A (en) * 2007-06-22 2009-02-12 Panasonic Corp Nonaqueous secondary battery, battery pack, power source system, and electrically powered equipment
JP2009301765A (en) * 2008-06-11 2009-12-24 Sony Corp Electrode with porous protective membrane, nonaqueous electrolyte secondary battery, and method of manufacturing electrode with porous protective membrane
JP2010061912A (en) * 2008-09-02 2010-03-18 Tdk Corp Method for manufacturing electrode, and electrode
JP2014032758A (en) * 2012-08-01 2014-02-20 Nippon Zeon Co Ltd Method of manufacturing electrode for lithium ion secondary battery, and lithium ion secondary battery

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108630893A (en) * 2017-03-23 2018-10-09 株式会社东芝 Electrode complex, secondary cell, battery pack and vehicle
JP2018160420A (en) * 2017-03-23 2018-10-11 株式会社東芝 Electrode composite, secondary battery, battery pack, and vehicle
US10446841B2 (en) 2017-03-23 2019-10-15 Kabushiki Kaisha Toshiba Electrode composite, secondary battery, battery pack and vehicle
CN108630893B (en) * 2017-03-23 2021-05-07 株式会社东芝 Electrode composite, secondary battery, battery pack, and vehicle
CN111937189A (en) * 2018-02-06 2020-11-13 积水化学工业株式会社 Electrode for lithium ion secondary battery, method for producing same, and lithium ion secondary battery
EP3754755A4 (en) * 2018-02-06 2022-01-05 Sekisui Chemical Co., Ltd. Lithium ion secondary battery electrode, production method for same, and lithium ion secondary battery
CN111490229A (en) * 2019-01-25 2020-08-04 株式会社理光 Electrode and its manufacturing method, electrode element, electrochemical element
JP2020119887A (en) * 2019-01-25 2020-08-06 株式会社リコー Electrode and manufacturing method thereof, electrode element, and electrochemical element
US11527748B2 (en) 2019-01-25 2022-12-13 Ricoh Company, Ltd. Electrode, electrode element, electrochemical element, and method for manufacturing electrode
WO2023065927A1 (en) * 2021-10-18 2023-04-27 宁德时代新能源科技股份有限公司 Pole piece, assembly, cell, battery, device, and pole piece manufacturing method and system
CN116589892A (en) * 2022-02-14 2023-08-15 朴力美电动车辆活力株式会社 Method for producing slurry for insulating protective layer of secondary battery and apparatus for producing slurry for insulating protective layer of secondary battery

Similar Documents

Publication Publication Date Title
JP4766348B2 (en) Lithium secondary battery and manufacturing method thereof
KR101513821B1 (en) Battery electrode and use thereof
JP2010170965A (en) Positive electrode for lithium secondary battery, and its manufacturing method
KR101914173B1 (en) Sodium electrode and sodium secondary battery comprising the same
JPWO2010084622A1 (en) Positive electrode for lithium secondary battery and its utilization
JP2015176856A (en) Negative electrode, method of manufacturing the same, and power storage device
JP5590381B2 (en) Lithium ion secondary battery
JP6338104B2 (en) Positive electrode for lithium ion secondary battery and method for producing the same, lithium ion secondary battery and method for producing the same
JP6044427B2 (en) Current collector for positive electrode of lithium ion secondary battery, positive electrode for lithium ion secondary battery, and lithium ion secondary battery
JP6327011B2 (en) Electrode for power storage device, power storage device, and method for manufacturing electrode for power storage device
JP2015109214A (en) Collector and lithium ion secondary battery
JP2015056208A (en) Electrode having protective layer formed on active material layer
KR101757978B1 (en) Nonaqueous electrolyte secondary battery and method of manufacturing the same, and separator for nonaqueous electrolyte secondary battery
JP2015002008A (en) Electrode including protective layer formed on active material layer
JP5517009B2 (en) Lithium ion secondary battery manufacturing method
JP2013246900A (en) Secondary battery
JP6597267B2 (en) Lithium ion secondary battery
JP6357863B2 (en) Positive electrode, power storage device, and method of manufacturing positive electrode
JP6135931B2 (en) Power storage device manufacturing method and power storage device
JP6844602B2 (en) electrode
JP2010251047A (en) Manufacturing method of cathode
WO2015198519A1 (en) Electricity storage device electrode, electricity storage device and electricity storage device electrode production method
JP6926910B2 (en) Rechargeable battery
JP2013191484A (en) Negative electrode active material layer, manufacturing method therefor and nonaqueous electrolyte secondary cell
JP2016111013A (en) Secondary battery electrode, secondary battery, and manufacturing methods therefor

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20160610

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20170313

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20170316

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20171019