WO2013002273A1

WO2013002273A1 - Lithium ion secondary cell, current collector constituting negative electrode of secondary cell, and electrolytic copper foil constituting negative-electrode current collector

Info

Publication number: WO2013002273A1
Application number: PCT/JP2012/066413
Authority: WO
Inventors: 鈴木　昭利; 健作篠崎
Original assignee: 古河電気工業株式会社
Priority date: 2011-06-28
Filing date: 2012-06-27
Publication date: 2013-01-03
Also published as: JP5158918B2; CN103460462A; TWI605627B; JPWO2013002273A1; KR20140023955A; KR101606251B1; TW201312826A

Abstract

Provided is an electrolytic copper foil having excellent coatability by an active material slurry, high cell capacity, minimal cell capacity loss even after repeated charge-discharge cycles, and nearly the same morphology on both sides thereof, such that an active material coating film does not peel away from the copper foil as a negative-electrode current collector. Also provided is a lithium ion secondary cell wherein the electrolytic copper foil is a current collector, an active material is deposited on the current collector to form a negative electrode, and the negative electrode is incorporated into the lithium ion secondary cell. The electrolytic copper foil constitutes a negative-electrode current collector of the lithium ion secondary cell, both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited sides have a granular crystalline structure. In the current collector comprising the electrolytic copper foil constituting the negative electrode of the lithium ion secondary cell, both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited sides are configured from a granular crystalline structure.

Description

リチウムイオン二次電池、該二次電池の負極電極を構成する集電体、並びに該負極電極集電体を構成する電解銅箔Lithium ion secondary battery, current collector constituting the negative electrode of the secondary battery, and electrolytic copper foil constituting the negative electrode current collector

　本発明は、正極と、負極集電体の表面に負極活物質層が形成された負極と、非水電解液とを備えるリチウムイオン二次電池、該二次電池の負極電極を構成する集電体、ならびに該負極電極集電体を構成する電解銅箔に関するものである。 The present invention relates to a lithium ion secondary battery comprising a positive electrode, a negative electrode having a negative electrode active material layer formed on the surface of a negative electrode current collector, and a non-aqueous electrolyte, and a current collector constituting the negative electrode of the secondary battery And an electrolytic copper foil constituting the negative electrode current collector.

　正極と、両面が平滑な電解銅箔からなる負極集電体の表面に負極活物質層としてカーボン粒子を塗布、乾燥し、さらにプレスした負極と、非水電解液を備えるリチウムイオン二次電池は現在、携帯電話、ノートタイプパソコン等に使用されている。このリチウムイオン二次電池の負極集電体には、電解により製造された、いわゆる「未処理銅箔」に防錆処理を施したものが使用されている。 A lithium ion secondary battery comprising a positive electrode and a negative electrode current collector made of an electrolytic copper foil with smooth both surfaces coated with carbon particles as a negative electrode active material layer, dried and further pressed, and a non-aqueous electrolyte Currently, it is used for mobile phones and notebook computers. As the negative electrode current collector of the lithium ion secondary battery, a so-called “untreated copper foil” manufactured by electrolysis is subjected to rust prevention treatment.

　前記リチウムイオン二次電池用負極集電体としての銅箔は、特許文献１に開示されているように、粗面を平滑にしさらに光沢面と粗面と（銅箔の両面）の表面粗さの差を小さくした電解銅箔を用いることにより、電池の充放電効率の低下を抑えることが可能である。 As disclosed in Patent Document 1, the copper foil as the negative electrode current collector for a lithium ion secondary battery has a roughened surface and a surface roughness of a glossy surface and a rough surface (both surfaces of the copper foil). By using an electrolytic copper foil with a small difference, it is possible to suppress a decrease in charge / discharge efficiency of the battery.

　上記のような粗面が平滑で光沢面と粗面との表面粗さの差を小さくした電解銅箔は、硫酸銅－硫酸電解液に各種水溶性高分子物質、各種界面活性剤、各種有機イオウ系化合物、塩化物イオンなどを適宜選定して添加した電解液を使用して、回転するチタンドラム陰極に銅を電解析出させ、所定の厚さになったところでこれを剥離し巻き取ることによって製造されている。
　例えば、硫酸銅－硫酸電解液にメルカプト基を持つ化合物、塩化物イオン、並びに分子量１０，０００以下の低分子量膠及び高分子多糖類を添加して電解銅箔を製造する技術が提案されている（特許文献１参照）。
　この電解銅箔は引張強さが３００～３５０Ｎ／ｍｍ^２であり、前記カーボン粒子を活物質とした負極用集電体（銅箔）として使用する場合、適度な伸びと併せて好適な材料である。 Electrolytic copper foil with a smooth surface as described above and a small difference in surface roughness between glossy and rough surfaces is made of copper sulfate-sulfuric acid electrolyte, various water-soluble polymer substances, various surfactants, various organic substances. Using an electrolytic solution that has been appropriately selected and added with sulfur compounds, chloride ions, etc., copper is electrolytically deposited on a rotating titanium drum cathode, and when it reaches a predetermined thickness, it is peeled off and wound up. Is manufactured by.
For example, a technique for producing an electrolytic copper foil by adding a compound having a mercapto group, a chloride ion, a low molecular weight glue having a molecular weight of 10,000 or less, and a high molecular weight polysaccharide to a copper sulfate-sulfuric acid electrolytic solution has been proposed. (See Patent Document 1).
This electrolytic copper foil has a tensile strength of 300 to 350 N / mm ² and is a suitable material in combination with appropriate elongation when used as a negative electrode current collector (copper foil) using the carbon particles as an active material. is there.

　さらに、粗面の粗さが平滑な電解銅箔が提案されており、現在主流であるカーボン系活物質を使用するリチウムイオン二次電池用には、このタイプの粗面が平滑で、光沢面と粗面との表面粗さの差が小さい銅箔が主に使用されている（特許文献２、特許文献３参照）。 In addition, electrolytic copper foils with a smooth rough surface have been proposed. For lithium-ion secondary batteries using carbon-based active materials, which are currently mainstream, this type of rough surface is smooth and glossy. A copper foil having a small difference in surface roughness between a rough surface and a rough surface is mainly used (see Patent Document 2 and Patent Document 3).

　ところで近年、リチウムイオン二次電池の高容量化を目的として、充電の際に電気化学的にリチウムと合金化する合金系活物質、例えばアルミニウム、シリコン、錫などを負極活物質として用いるリチウムイオン二次電池が提案されている（特許文献４参照）。 In recent years, for the purpose of increasing the capacity of lithium ion secondary batteries, lithium ion secondary batteries that use an alloy active material that is electrochemically alloyed with lithium during charging, such as aluminum, silicon, and tin, as the negative electrode active material. A secondary battery has been proposed (see Patent Document 4).

　高容量化を目的としたリチウムイオン二次電池用負極は、ＣＶＤ法やスパッタリング法により、銅箔などの集電体の上に、例えばシリコンを非晶質シリコン薄膜や微結晶シリコン薄膜として堆積し形成している。このような方法で作成した活物質の薄膜層は集電体に密着するため、良好な充放電サイクル特性を示すことが見出されている（特許文献５参照）。
　また、最近では粉末シリコンあるいはシリコン化合物をイミド系のバインダーとともに有機溶媒によりスラリー状にして銅箔上に塗布し、乾燥、プレスする形成方法も開発されている。（特許文献６参照） A negative electrode for a lithium ion secondary battery for the purpose of increasing the capacity is obtained by depositing, for example, silicon as an amorphous silicon thin film or a microcrystalline silicon thin film on a current collector such as a copper foil by a CVD method or a sputtering method. Forming. It has been found that the thin film layer of the active material produced by such a method is in close contact with the current collector, and thus exhibits good charge / discharge cycle characteristics (see Patent Document 5).
Recently, a forming method has also been developed in which powdered silicon or a silicon compound is slurried with an imide-based binder in an organic solvent, applied onto a copper foil, dried and pressed. (See Patent Document 6)

負極活物質の種類がカーボン系あるいは合金系いずれの場合であっても、電池容量が高く、充放電サイクルを繰り返しても電池容量の劣化が少なく、負極集電体である銅箔から活物質薄膜層が剥離しない銅箔が要求されている。 Regardless of whether the type of the negative electrode active material is carbon or alloy, the battery capacity is high, and even when the charge / discharge cycle is repeated, there is little deterioration of the battery capacity. There is a need for a copper foil that does not peel off.

特許第３７４２１４４号Japanese Patent No. 3742144 特開２００４－２６３２８９号公報JP 2004-263289 A 特開２００４－１６２１４４号公報JP 2004-162144 A 特開平１０－２５５７６８号公報JP-A-10-255768 特開２００２－０８３５９４号公報Japanese Patent Laid-Open No. 2002-083594 特開２００７－２２７３２８号公報JP 2007-227328 A

　本発明は、活物質スラリーの塗布性に優れ、電池容量が高く、充放電サイクルを繰り返しても電池容量の劣化が少なく、負極集電体である銅箔から活物質塗膜層が剥離しない両面形状が同程度の電解銅箔を提供し、該電解銅箔を集電体とし、該集電体に活物質を堆積した負極電極とし、該負極電極を組み込んだリチウムイオン二次電池を提供することを課題とする。 The present invention is excellent in coating properties of the active material slurry, has a high battery capacity, little deterioration of the battery capacity even after repeated charge / discharge cycles, and the active material coating layer does not peel from the copper foil as the negative electrode current collector. Provided is an electrolytic copper foil having the same shape, and uses the electrolytic copper foil as a current collector, a negative electrode in which an active material is deposited on the current collector, and a lithium ion secondary battery incorporating the negative electrode This is the issue.

　本発明のリチウムイオン二次電池は、正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池であって、該リチウムイオン二次電池の負極を構成する前記集電体は電解銅箔からなり、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織である。 The lithium ion secondary battery of the present invention is a lithium ion secondary battery comprising a positive electrode, a negative electrode in which an electrode constituent active material layer is formed on the surface of a current collector, and a non-aqueous electrolyte, The current collector constituting the negative electrode of the ion secondary battery is made of an electrolytic copper foil. Both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited surface has a crystalline structure of granular crystals.

　本発明のリチウムイオン二次電池用集電体は、正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池の前記負極を構成する集電体であって、該集電体は電解銅箔からなり、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織である。 The current collector for a lithium ion secondary battery of the present invention is a lithium ion secondary battery comprising a positive electrode, a negative electrode in which an electrode constituting active material layer is formed on the surface of the current collector, and a non-aqueous electrolyte. A current collector constituting a negative electrode, wherein the current collector is made of an electrolytic copper foil, both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited surface is a crystal structure of a granular crystal.

　本発明のリチウムイオン二次電池負極集電体用電解銅箔は、正極と負極と非水電解液とを備えるリチウムイオン二次電池の前記負極集電体を構成する電解銅箔であって、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織である。 An electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery of the present invention is an electrolytic copper foil constituting the negative electrode current collector of a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, Both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposition surface has a crystal structure of granular crystals.

　本発明のリチウムイオン二次電池は、正極及び集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池であって、前記負極を構成する前記集電体は銅を電解析出して形成する電解銅箔であり、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面である。 A lithium ion secondary battery of the present invention is a lithium ion secondary battery comprising a negative electrode in which an electrode-constituting active material layer is formed on the surfaces of a positive electrode and a current collector, and a non-aqueous electrolyte, wherein the negative electrode The current collector constituting is an electrolytic copper foil formed by electrolytic deposition of copper, and the first surface of the electrolytic copper foil is a surface formed by copper electrodeposition of a crystal structure of granular crystals on the drum surface, The second surface opposite to the first surface is a surface formed by copper electrodeposition of a granular crystal structure on the back side of the first surface after the first surface film formation.

　本発明のリチウムイオン二次電池用負極集電体は、正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池の前記二次電池を構成する負極集電体であって、該負極集電体は銅を電解析出して形成する電解銅箔であり、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面である。 A negative electrode current collector for a lithium ion secondary battery of the present invention is a lithium ion secondary battery comprising a positive electrode, a negative electrode in which an electrode constituent active material layer is formed on the surface of the current collector, and a non-aqueous electrolyte. A negative electrode current collector constituting the secondary battery, wherein the negative electrode current collector is an electrolytic copper foil formed by electrolytic deposition of copper, and the first surface of the electrolytic copper foil is a granular crystal on a drum surface. The second surface opposite to the first surface is formed by copper electrodeposition of granular crystals on the back side of the first surface after the first surface film formation. It is the formed surface.

　本発明のリチウムイオン二次電池負極集電体用電解銅箔は、正極と負極と非水電解液とを備えるリチウムイオン二次電池の前記二次電池を構成する負極集電体用電解銅箔であって、該電解銅箔は銅を電解析出して形成する電解銅箔であり、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面である。 The electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery of the present invention is an electrolytic copper foil for a negative electrode current collector constituting the secondary battery of a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte. The electrolytic copper foil is an electrolytic copper foil formed by electrolytic deposition of copper, and the first surface of the electrolytic copper foil is a surface formed by copper electrodeposition of a granular crystal structure on the drum surface. The second surface opposite to the first surface is a surface formed by copper electrodeposition of a granular crystal structure on the back side of the first surface after the first surface film formation.

　本発明は、活物質スラリーの塗布性に優れ、電池容量が高く、充放電サイクルを繰り返しても電池容量の劣化が少なく、負極集電体である銅箔から活物質塗膜層が剥離しない両面形状が同程度の電解銅箔を提供することができる。
　また本発明は、前記電解銅箔を集電体とし、該集電体に活物質を堆積して負極電極とし、該負極電極を組み込んだリチウムイオン二次電池とすることで、負極集電体である銅箔から活物質堆積層が剥離しない集電体を提供でき、該集電体により負極電極を構成することで電池容量が高く、充放電サイクルを繰り返しても電池容量の劣化が少なくリチウムイオン二次電池を提供することができる。 The present invention is excellent in coating properties of the active material slurry, has a high battery capacity, little deterioration of the battery capacity even after repeated charge / discharge cycles, and the active material coating layer does not peel from the copper foil as the negative electrode current collector. An electrolytic copper foil having the same shape can be provided.
Further, the present invention provides a negative electrode current collector by using the electrolytic copper foil as a current collector, depositing an active material on the current collector as a negative electrode, and forming a lithium ion secondary battery incorporating the negative electrode. A current collector in which the active material deposition layer does not peel from the copper foil can be provided, and the negative electrode is constituted by the current collector, so that the battery capacity is high, and the battery capacity is hardly deteriorated even after repeated charge / discharge cycles. An ion secondary battery can be provided.

図１は両面の形状が同様な電解銅箔を製造する工程の一実施例を示す説明図である。FIG. 1 is an explanatory view showing an example of a process for producing an electrolytic copper foil having the same shape on both sides. 図２は従来の電解銅箔を製造する装置の説明図である。FIG. 2 is an explanatory view of a conventional apparatus for producing an electrolytic copper foil. 図３は本発明電解銅箔の第一の実施例を示し、Ａ１は最初に形成される電解析出面、Ａ２は次に形成される電解析出面を示す顕微鏡写真（ＳＥＭ）である。FIG. 3 shows a first example of the electrolytic copper foil of the present invention, wherein A1 is an electrolytic deposition surface formed first, and A2 is a micrograph (SEM) showing an electrolytic deposition surface formed next. 図４は本発明電解銅箔の第二の実施例を示し、Ａ１は最初に形成される電解析出面、Ａ２は次に形成される電解析出面を示す顕微鏡写真（ＳＥＭ）である。FIG. 4 shows a second embodiment of the electrolytic copper foil of the present invention, wherein A1 is an electrolytic deposition surface formed first, and A2 is a micrograph (SEM) showing an electrolytic deposition surface formed next. 図５は本発明電解銅箔の第三の実施例を示し、Ａ１は最初に形成される電解析出面、Ａ２は次に形成される電解析出面を示す顕微鏡写真（ＳＥＭ）である。FIG. 5 shows a third embodiment of the electrolytic copper foil of the present invention, wherein A1 is an electrolytic deposition surface formed first, and A2 is a micrograph (SEM) showing an electrolytic deposition surface formed next. 図６は本発明電解銅箔の第四の実施例を示し、Ａ１は最初に形成される電解析出面、Ａ２は次に形成される電解析出面を示す顕微鏡写真（ＳＥＭ）である。FIG. 6 shows a fourth embodiment of the electrolytic copper foil of the present invention, in which A1 is an electrolytic deposition surface formed first, and A2 is a micrograph (SEM) showing an electrolytic deposition surface formed next. 図７は従来の電解銅箔の顕微鏡写真（ＳＥＭ）であり、Ｘ１はドラム面、Ｙ１はドラム面を示す。FIG. 7 is a micrograph (SEM) of a conventional electrolytic copper foil, where X1 represents a drum surface and Y1 represents a drum surface.

　本明細書では、電解銅箔の電解液に接していた面を「電解析出面」と表現する。
　本発明電解銅箔は「第一面と第一面の反対側の第二面の両面とも電解析出面」である。両面とも電解析出面の電解銅箔とは例えば後述する図１に示す製箔装置により製箔することができるように、銅箔の両面共に電解液に接していた面で構成されている。 In this specification, the surface of the electrolytic copper foil that is in contact with the electrolytic solution is expressed as an “electrolytic deposition surface”.
The electrolytic copper foil of the present invention is “both electrolytic deposition surfaces on the first surface and the second surface opposite to the first surface”. Both sides of the electrolytic copper foil on the electrolytically deposited surface are constituted by a surface where both sides of the copper foil are in contact with the electrolytic solution so that the foil can be made by a foil making apparatus shown in FIG.

　電解銅箔は一般に図２に示すように、回転するチタンドラム２１とその下側に不溶性陽極２２（以下ＤＳＡと記す。）を配置して、チタンドラム２１とＤＳＡ２２の間に硫酸銅－硫酸の電解液２３を流し、チタンドラム２１を陰極とし、ＤＳＡ２２を陽極としてチタンドラム－ＤＳＡ間に電流を流すことにより銅箔２４を製造する。
　チタンドラム２１とＤＳＡ２２の間に電流を流すと、チタンドラム２１上に銅が電解析出する。これを所定の厚さになったところで連続的に引き剥がし巻き取ることにより電解銅箔２４を製造する。通常この状態の箔を「未処理銅箔」と称する。 As shown in FIG. 2, the electrolytic copper foil generally has a rotating titanium drum 21 and an insoluble anode 22 (hereinafter referred to as DSA) disposed below the rotating titanium drum 21 and a copper sulfate-sulfuric acid solution between the titanium drum 21 and the DSA 22. A copper foil 24 is produced by flowing an electrolytic solution 23 and flowing a current between the titanium drum and the DSA with the titanium drum 21 as a cathode and the DSA 22 as an anode.
When a current is passed between the titanium drum 21 and the DSA 22, copper is electrolytically deposited on the titanium drum 21. The electrolytic copper foil 24 is manufactured by continuously peeling and winding it up at a predetermined thickness. Usually, the foil in this state is referred to as “untreated copper foil”.

　図２に示す製法で製造される電解銅箔２４は電解液２３に接していた面２４１とチタンドラム２１に接触していた面２４２とでは形状が異なっている。
　通常電解液２３に接していた面２４１を「粗面」と呼び、チタンドラム２１に接していた面２４２を「光沢面」と称する。 The shape of the electrolytic copper foil 24 manufactured by the manufacturing method shown in FIG. 2 is different between the surface 241 in contact with the electrolytic solution 23 and the surface 242 in contact with the titanium drum 21.
The surface 241 that is normally in contact with the electrolytic solution 23 is referred to as a “rough surface”, and the surface 242 that is in contact with the titanium drum 21 is referred to as a “glossy surface”.

　しかし、リチウムイオン二次電池の負極集電体用の電解銅箔の場合、前記特許文献１～３に示すように、電解液に接していた面の方がチタンドラムに接していた面より、むしろ平滑な電解銅箔が製造できるため、リチウムイオン二次電池用銅箔業界内では電解液に接していた面２４１を「電解析出面」あるいは「電析面」、チタンドラムに接していた面２４２を「ドラム面」と称している。本明細書ではリチウムイオン二次電池用銅箔業界内で一般化している「電解析出面」と「ドラム面」を採用し、前述のように電解銅箔の電解液に接していた面を「電解析出面」と表現する。 However, in the case of the electrolytic copper foil for the negative electrode current collector of the lithium ion secondary battery, as shown in Patent Documents 1 to 3, the surface in contact with the electrolytic solution is more in contact with the titanium drum, Rather, since a smooth electrolytic copper foil can be produced, the surface 241 that has been in contact with the electrolyte in the copper foil industry for lithium ion secondary batteries is referred to as an “electrolytic deposition surface” or “electrodeposition surface”, or a surface that has been in contact with a titanium drum. Reference numeral 242 is referred to as a “drum surface”. In this specification, “electrolytic deposition surface” and “drum surface”, which are generalized in the copper foil industry for lithium ion secondary batteries, are adopted, and the surface of the electrolytic copper foil in contact with the electrolytic solution as described above is “ It is expressed as “electrolytically deposited surface”.

　チタンドラムに接していた「ドラム面」は目視では光沢があり一見平滑な面に見えるが、ＳＥＭで観察すると図７（Ｙ１）に示すように、箔のＭＤ方向（縦方向）に筋状の凹凸がある。
　これに対して図３～図６に示す「電解析出面」は筋状の凹凸は見られず「ドラム面」より平滑な面になっている。
　これは、「ドラム面」がチタンドラムに接していた面であることに原因がある。チタンドラムは表面を研磨した後、図２に示すような電解槽２６にセットして銅箔製造（製箔）を行う。
　この時５０℃前後の比較的高い温度の硫酸銅－硫酸の電解液を使用するため、製造を続けるうちチタンドラム２１面は次第に荒れて銅箔２４が剥がれにくくなる。これを避けるため、ある一定期間銅箔を製造した後、定期的にチタンドラム面を研磨して、再び製造を続ける。 The “drum surface” that was in contact with the titanium drum looks glossy and looks smooth at first glance, but when observed with an SEM, as shown in FIG. There are irregularities.
On the other hand, the “electrolytically deposited surface” shown in FIGS. 3 to 6 is smoother than the “drum surface” without any streaks.
This is because the “drum surface” is the surface in contact with the titanium drum. After the surface of the titanium drum is polished, it is set in an electrolytic cell 26 as shown in FIG.
At this time, since a copper sulfate-sulfuric acid electrolytic solution having a relatively high temperature of about 50 ° C. is used, the surface of the titanium drum 21 is gradually roughened and the copper foil 24 is hardly peeled off during the continuous production. In order to avoid this, after manufacturing the copper foil for a certain period, the titanium drum surface is periodically polished and the manufacturing is continued again.

　通常、チタンドラム表面はナイロン不織布などに酸化アルミ、シリコンカーバイト等の研磨砥粒を均一に接着含浸させた円筒形研磨バフによって行う。
　「ドラム面」は上記のようなバフ等により表面研磨を行ったチタンドラムの「研磨筋」のレプリカになっている。
　従って、通常の製造方法では「ドラム面」のＭＤ方向（縦方向）に、図７（Ｙ１）に示す様な筋状の凹凸が存在することは避けることができない。 Usually, the surface of the titanium drum is formed by a cylindrical polishing buff obtained by uniformly bonding and impregnating abrasive grains such as aluminum oxide and silicon carbide to a nylon nonwoven fabric.
The “drum surface” is a replica of the “polishing streaks” of the titanium drum that has been surface-polished by the buff as described above.
Therefore, in the normal manufacturing method, it is inevitable that streak-like irregularities as shown in FIG. 7 (Y1) exist in the MD direction (vertical direction) of the “drum surface”.

　図７に示す銅箔は、これまでノートパソコン、携帯電話等の民生用のリチウムイオン二次電池の負極集電体として使用されてきたが、この「ドラム面」と「電解析出面」の形状の違いはこれまでは何の問題も起こさなかった。
　例えば、活物質塗布時の塗布性の違い、あるいは電池になった後の充放電効率の違いといった点は特に問題にされるようなことはなかった。 The copper foil shown in FIG. 7 has been used as a negative electrode current collector for consumer-use lithium ion secondary batteries such as notebook computers and mobile phones, but the shape of this “drum surface” and “electrolytic deposition surface” The difference has not caused any problems so far.
For example, the difference in applicability at the time of applying the active material or the difference in charge / discharge efficiency after becoming a battery has not been particularly problematic.

　しかし、ＨＥＶ、ＥＶ、ＰＨＥＶといった自動車用のリチウムイオン二次電池の負極集電体に電解銅箔を採用した場合、電解銅箔の「ドラム面」と「電解析出面」で、リチウムイオン二次電池になった後の充放電効率の違いが問題視されるようになってきた。 However, when electrolytic copper foil is used as the negative electrode current collector of lithium ion secondary batteries for automobiles such as HEV, EV, and PHEV, the lithium ion secondary on the “drum surface” and “electrolytic deposition surface” of the electrolytic copper foil The difference in charge and discharge efficiency after becoming a battery has been regarded as a problem.

　問題視される原因は、リチウムイオン二次電池の負極を製造する場合、集電体（銅箔）を連続的に走行させてスラリー状の活物質を塗布し、乾燥して巻き取る方式で負極製造を行うが、銅箔を走行させるスピードが自動車用電池製造の場合の方が、民生用の電池を製造する場合より、はるかに早いためと考えられる。 The cause of the problem is that when manufacturing a negative electrode for a lithium ion secondary battery, a current collector (copper foil) is continuously run to apply a slurry-like active material, and then dried and wound up. Although the manufacturing is performed, it is considered that the speed of running the copper foil is much faster in the case of manufacturing a battery for automobiles than in the case of manufacturing a battery for consumer use.

　また、充放電効率についても、自動車用の場合は充放電効率の低下が１０年程度使用した後でもある一定以上の効率が必要なのに対し、民生用の場合は１～２年程度の後ある一定以上の効率が必要というように、はるかに厳しいレベルの性能が要求される。 In addition, the charge / discharge efficiency for automobiles needs to be higher than a certain level even after 10 years of decline in charge / discharge efficiency, while for consumer use, it is constant after about 1-2 years. A much stricter level of performance is required, such as the need for the above efficiency.

　以上のように、自動車用のリチウムイオン二次電池に要求される厳しい評価基準で電池製造後の充放電効率を電解銅箔の「ドラム面」と「電解析出面」で比較を行うと、「ドラム面」の方が「電解析出面」より充放電効率の劣化が大きい（早い）傾向が見られる。 As described above, when comparing the charging / discharging efficiency after battery production on the `` drum surface '' and the `` electrolytic deposition surface '' of the electrolytic copper foil according to strict evaluation criteria required for lithium ion secondary batteries for automobiles, The “drum surface” tends to have a greater (faster) deterioration in charge / discharge efficiency than the “electrolytic deposition surface”.

　この現象は、高容量化を目的として、充電の際に電気化学的にリチウムと合金化する合金系活物質、例えばアルミニウム、シリコン、錫などを負極活物質として用いるリチウムイオン二次電池でも同様に見られる。 This phenomenon also applies to lithium-ion secondary batteries that use an alloy-based active material that is electrochemically alloyed with lithium during charging, such as aluminum, silicon, or tin, as the negative electrode active material for the purpose of increasing capacity. It can be seen.

　アルミニウム、シリコン、錫などを負極活物質として用いるリチウムイオン二次電池の充放電効率の低下は、カーボン系活物質を使う場合よりも少ないサイクル、例えば５０～１００サイクル程度で顕著に現れる。
　この場合も電解銅箔の「ドラム面」と「電解析出面」の比較を行うと、充放電効率の点では「ドラム面」の方が「電解析出面」より充放電効率の劣化が大きい傾向が見られる。 The decrease in charge / discharge efficiency of a lithium ion secondary battery using aluminum, silicon, tin, or the like as a negative electrode active material appears remarkably in fewer cycles, for example, about 50 to 100 cycles than when a carbon-based active material is used.
In this case as well, when comparing the “drum surface” and the “electrolytic deposition surface” of the electrolytic copper foil, in terms of charge / discharge efficiency, the “drum surface” tends to have a greater deterioration in charge / discharge efficiency than the “electrolytic deposition surface”. Is seen.

　さらに本発明者等はこの現象について詳細に解析したところ、「ドラム面」と「電解析出面」の表面形状の違いが大きな要因であるということを突き止めた。
　すなわち、「ドラム面」の筋状の凹凸は、充放電効率の点で劣化を引き起こしやすいことが判明した。この原因については明らかではないが、負極活物質と電解銅箔の接触が「電解析出面」の方が「ドラム面」より接触面積が大きいためと推定される。 Furthermore, the present inventors analyzed this phenomenon in detail, and ascertained that the difference in surface shape between the “drum surface” and the “electrolytic deposition surface” was a major factor.
That is, it has been found that streaky irregularities on the “drum surface” are likely to cause deterioration in terms of charge / discharge efficiency. Although the cause of this is not clear, it is presumed that the contact area between the negative electrode active material and the electrolytic copper foil is larger on the “electrolytic deposition surface” than on the “drum surface”.

　本発明者等は、「ドラム面」と「電解析出面」との表面形状を一致させるために、製造後の銅箔の「ドラム面」に電解銅箔製造時と同じ電解液を用いて「ドラム面」の筋状凹凸を消す厚さの銅めっきを行い「ドラム面」も「電解析出面」と同様の形状とし、リチウムイオン二次電池用陰極集電体とすることを検討した。
　また、もうひとつの実施態様として、「ドラム面」の筋状凹凸を消すためには、「電解析出面」と同様の形状が得られれば、電解銅箔製造と異なる組成の電解液を用いることも効果的であると考え鋭意検討した。 In order to make the surface shapes of the “drum surface” and the “electrolytic deposition surface” coincide with each other, the present inventors use the same electrolytic solution as that used when producing the electrolytic copper foil on the “drum surface” of the copper foil after production. Copper plating was made to remove the streaks on the “drum surface”, and the “drum surface” was made to have the same shape as the “electrolytic deposition surface” to make a cathode current collector for a lithium ion secondary battery.
As another embodiment, in order to eliminate the streaky irregularities on the “drum surface”, an electrolytic solution having a composition different from that of the electrolytic copper foil production may be used as long as the same shape as the “electrolytic deposition surface” is obtained. Was also considered effective.

　リチウムイオン二次電池負極集電体用電解銅箔の表面は平滑で光沢がある面が適している。これは特許例１～３に示す通りである。こうしたリチウムイオン二次電池用集電体として適する平滑で光沢がある表面とするためには、銅の結晶組織を粒状晶とすることが効果的である。 A smooth and glossy surface is suitable for the surface of the electrolytic copper foil for the negative electrode current collector of the lithium ion secondary battery. This is as shown in Patent Examples 1 to 3. In order to obtain a smooth and glossy surface suitable as such a current collector for a lithium ion secondary battery, it is effective to make the crystal structure of copper granular.

　本発明の充放電効率劣化を防止する改良されたリチウムイオン二次電池負極集電体用電解銅箔は、先の製箔工程で形成される「電解析出面（第一表面）」は粒状晶組織をもつ光沢面であり、「ドラム面（第二表面）」側は次の工程で、先の工程で形成された筋状の凹凸を消す厚さの粒状晶銅の電析を行い、両面とも「電解析出面」と同様な粒状晶からなる表面形状として、平滑で光沢をもった銅箔に仕上げられる。 The improved electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery for preventing deterioration of charge / discharge efficiency of the present invention is an “electrolytic precipitation surface (first surface)” formed in the previous foil-making process. It is a glossy surface with a texture, and the “drum surface (second surface)” side is the next step, and electrodeposits of granular crystal copper with a thickness that eliminates the streaks formed in the previous step. Both have a smooth and glossy copper foil as a surface shape composed of granular crystals similar to the “electrolytically deposited surface”.

　上記電解銅箔の具体的な製造方法の一例を図１に示す。
　第一ドラム１１で粒状晶の結晶組織の銅箔１を製造したのちそれを引き剥がし、第二ドラム１２で銅箔１のドラム面１０１側に粒状晶の結晶組織の銅電析を行い、チタンドラム１１の研磨筋を埋めて、ドラム面１０１を電解析出面１０３とし、電解析出面１０２と共に両表面の表面形状を同様にする。 An example of a specific method for producing the electrolytic copper foil is shown in FIG.
After producing the copper foil 1 having a crystal structure of granular crystals with the first drum 11, the copper foil 1 is peeled off, and copper electrodeposition of the crystal structure of granular crystals is performed on the drum surface 101 side of the copper foil 1 with the second drum 12. The surface of both surfaces is made the same as that of the electrolytic deposition surface 102 by filling the polishing surface of the drum 11 with the drum surface 101 as the electrolytic deposition surface 103.

　この場合、第一電解槽１６と第二電解槽１７の電解液１３、１８は同じ電解液にした方が製造上は都合がよいが、第一電解槽１６と第二電解槽１７とで液組成が異なる電解液を使用しても両面の表面形状を同様にすることは可能である。
　第一ドラム１１で粒状晶の結晶組織の銅電析を行い、第一電解槽１６とは組成の異なる銅電解液を用いても、第二ドラム１２で粒状晶の銅電析を行うことにより、両面の形状を同様にすることは可能である。 In this case, it is more convenient in manufacturing that the

electrolytic solutions

13 and 18 in the first electrolytic tank 16 and the second electrolytic tank 17 are the same electrolytic solution, but the first electrolytic tank 16 and the second electrolytic tank 17 are liquid solutions. Even when electrolytic solutions having different compositions are used, the surface shapes on both sides can be made the same.
By performing copper electrodeposition of the crystalline structure of the granular crystals on the first drum 11 and using a copper electrolyte having a composition different from that of the first electrolytic cell 16, It is possible to make the shape of both sides the same.

　なお、両面同形状の箔を得るためには、第一ドラムで形成した銅箔の厚さと第二ドラムで形成する銅被覆の厚さを同じにするやり方が製造上は容易である。しかし、第一ドラムで形成した銅箔の厚さの方を厚くし、第二ドラムで形成する銅被覆の厚さを薄くしても可能である。
　前者の方法は３５μｍ程度の厚い箔を製造する場合に適しているが、後者は６μｍ位の薄い箔を製造するのに適している。
　例えば、第一ドラムで３μｍの銅箔を製造し、第二ドラムで３μｍの銅被覆を行うのは事実上かなり難しい。第一ドラムで３μｍの銅箔を製造し、それを第二ドラムで銅被覆を３μｍ行うことは、第一ドラムで箔が薄く切れやすいため製造が難しい。
　これに対して後者の方法で、例えば第一ドラムで５．０μｍの銅箔を製造し、第二ドラムで１．０μｍの銅被覆を行うことは、第一ドラムで製造する銅箔の引張強さが充分高ければ可能である。
　なお、上記の製造の方法から、箔厚さとしては６～３５μｍが好適と考えられる。 In order to obtain a foil having the same shape on both sides, it is easy in manufacturing to make the thickness of the copper foil formed on the first drum the same as the thickness of the copper coating formed on the second drum. However, it is also possible to increase the thickness of the copper foil formed on the first drum and reduce the thickness of the copper coating formed on the second drum.
The former method is suitable for producing a foil having a thickness of about 35 μm, while the latter method is suitable for producing a thin foil having a thickness of about 6 μm.
For example, it is practically quite difficult to produce a 3 μm copper foil on the first drum and a 3 μm copper coating on the second drum. It is difficult to manufacture a copper foil having a thickness of 3 μm using the first drum and to cover the copper foil with 3 μm using the second drum because the foil is easily cut thinly on the first drum.
In contrast, the latter method, for example, producing 5.0 μm copper foil on the first drum and coating 1.0 μm copper on the second drum means that the tensile strength of the copper foil produced on the first drum is This is possible if the height is high enough.
From the above manufacturing method, it is considered that the foil thickness is preferably 6 to 35 μm.

　このように両面同形状の箔を得ることで、活物質スラリーを塗布した場合、同様な濡れ性が得られ、活物質塗布工程の条件設定が容易となり、両面の塗膜構造は同一になり、同程度の充放電特性が得られ、電池として極めて安定した性能を発揮するものと考えられる。 Thus, by obtaining a foil having the same shape on both sides, when applying the active material slurry, the same wettability is obtained, the condition setting of the active material application process becomes easy, and the coating film structure on both sides becomes the same, The same charge / discharge characteristics are obtained, and it is considered that the battery exhibits extremely stable performance.

　上述したように、本発明は集電体の表面に電極構成活物質層が形成されてなる正極及び負極を備えるリチウムイオン二次電池において、負極集電体は粒状晶組織をもつ銅を電解析出することによりドラム面及び電解析出面をもつ電解銅箔を最初に形成する。
　続いて、先の工程でドラム面に形成された筋状の凹凸を消す厚さに粒状晶の結晶組織の銅電析が行われ、上記電解銅箔の上に電解析出面となる銅層を設ける。このようにして製造した電解銅箔を負極集電体とし、該負極集電体に活物質を堆積して負極電極とし、該負極電極を組み込んでリチウムイオン二次電池とする。 As described above, the present invention is a lithium ion secondary battery including a positive electrode and a negative electrode in which an electrode constituent active material layer is formed on the surface of the current collector. First, an electrolytic copper foil having a drum surface and an electrolytic deposition surface is formed.
Subsequently, copper electrodeposition of the crystalline structure of the granular crystals is performed to a thickness that eliminates the streaky irregularities formed on the drum surface in the previous step, and a copper layer serving as an electrolytic deposition surface is formed on the electrolytic copper foil. Provide. The electrolytic copper foil thus produced is used as a negative electrode current collector, an active material is deposited on the negative electrode current collector to form a negative electrode, and the negative electrode is incorporated into a lithium ion secondary battery.

　さらには、本発明は平面状集電体の表面に電極構成活物質層が形成されてなる正極及び負極を備えるリチウムイオン二次電池において、負極集電体は粒状晶組織をもつ銅を電解析出することにより「ドラム面」及び「電解析出面」をもつ電解銅箔を最初に形成する。
　続いて、上記電解銅箔の「ドラム面」上に上述するように粒状晶の結晶組織の銅電析を行った銅箔を作成する。このようにして製造した電解銅箔の少なくとも一方の面に電極構成活物質層と密着性を高める表面処理を施して負極集電体とし、該負極集電体に活物質を堆積して負極電極とし、該負極電極を組み込んでリチウムイオン二次電池とする。 Furthermore, the present invention relates to a lithium ion secondary battery including a positive electrode and a negative electrode in which an electrode-constituting active material layer is formed on the surface of a planar current collector. First, an electrolytic copper foil having a “drum surface” and an “electrolytic deposition surface” is formed.
Then, the copper foil which performed the copper electrodeposition of the crystal structure of a granular crystal as mentioned above on the "drum surface" of the said electrolytic copper foil is created. At least one surface of the electrolytic copper foil thus manufactured is subjected to a surface treatment for improving adhesion with the electrode-constituting active material layer to form a negative electrode current collector, and the active material is deposited on the negative electrode current collector to form the negative electrode And incorporating the negative electrode into a lithium ion secondary battery.

　上記の箔は製箔後全く何の表面処理も行っていないため「未処理箔」に分類されるものである。「未処理箔」は何の表面処理も施さない中間製品である。これを電池用箔として使用するには、なんらかの表面処理を施す。
　通常、表面処理は防錆機能とともに電極構成活物質層と密着性を高めることを目的にして行う。 The above-mentioned foils are classified as “untreated foils” since no surface treatment is performed after the foil production. "Untreated foil" is an intermediate product that does not undergo any surface treatment. In order to use this as a battery foil, some surface treatment is applied.
Usually, the surface treatment is performed for the purpose of enhancing the adhesion to the electrode constituent active material layer together with the antirust function.

　防錆処理は、無機系の防錆処理或いは有機系の防錆処理が行われる。無機系防錆処理としてはクロメート処理等が行われる。有機系防錆処理としてはベンゾトリアゾール処理、シランカップリング剤処理などがあり、これらを単一に又は組み合わせて行うこともできる。 As the rust prevention treatment, an inorganic rust prevention treatment or an organic rust prevention treatment is performed. Chromate treatment or the like is performed as the inorganic rust prevention treatment. Examples of the organic rust preventive treatment include benzotriazole treatment and silane coupling agent treatment, and these can be performed singly or in combination.

　クロメート処理には重クロム酸イオンを含む水溶液を使用し、酸性でもアルカリ性でも良く、浸漬処理又は陰極電解処理を行う。なお、このクロメート処理では銅箔への付着形態は６価クロムから還元された３価クロムの酸化物又は水酸化物となっている。
　通常の薬品としては三酸化クロム、重クロム酸カリウム、重クロム酸ナトリウム等を使用する。 The chromate treatment uses an aqueous solution containing dichromate ions, which may be acidic or alkaline, and is subjected to immersion treatment or cathodic electrolysis treatment. In this chromate treatment, the form of adhesion to the copper foil is an oxide or hydroxide of trivalent chromium reduced from hexavalent chromium.
Usual chemicals include chromium trioxide, potassium dichromate, sodium dichromate and the like.

　有機系防錆処理としてのベンゾトリアゾール類にはベンゾトリアゾール、メチルベンゾトリアゾール、アミノベンゾトリアゾール、カルボキシベンゾトリアゾール等があり、水溶液として浸漬処理又はスプレー処理などにより施す。
　シランカップリング剤にはエポキシ基、アミノ基、メルカプト基、ビニル基を持つもの等多種あるが、電極構成活物質層との密着性に優れたものを使用すれば良く、水溶液又は溶媒を使用して浸漬処理又はスプレー処理などにより施す。
　以上の処理によりリチウムイオン二次電池負極集電体用銅箔が完成する。 Benzotriazoles as organic rust preventive treatments include benzotriazole, methylbenzotriazole, aminobenzotriazole, carboxybenzotriazole and the like, and are applied as an aqueous solution by immersion treatment or spray treatment.
There are various types of silane coupling agents such as those having an epoxy group, amino group, mercapto group, and vinyl group, but those having excellent adhesion to the electrode active material layer may be used, and an aqueous solution or solvent may be used. Apply by dipping or spraying.
The copper foil for lithium ion secondary battery negative electrode collectors is completed by the above process.

　以下実施例により本発明を更に詳細に説明するが、これらは本発明を限定するものではない。 Hereinafter, the present invention will be described in more detail by way of examples, but these examples do not limit the present invention.

＜実施例１＞
　図１に示す装置により電解銅箔を製箔した。即ち、回転するチタンドラム１１を陰極として、その下側にＤＳＡ１４を配置した第一電解槽１６により、チタンドラム１１とＤＳＡ１４の間に下記組成の硫酸銅－硫酸の電解液１３を流し、チタンドラム－ＤＳＡ間に電流を流して６μｍ厚さの電解銅箔１を製造した。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ヒドロキシエチルセルロース＝１～３０ｐｐｍ
　　低分子量ゼラチン（分子量３，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　この銅箔１の電解析出面１０２の粗さはＲｚ＝１．３μｍ、Ｒａ＝０．３μｍ、ドラム面１０１の粗さはＲｚ＝１．６μｍ、Ｒａ＝０．４μｍであった。 <Example 1>
An electrolytic copper foil was made using the apparatus shown in FIG. That is, a copper sulfate-sulfuric acid electrolyte solution 13 having the following composition is caused to flow between the titanium drum 11 and the DSA 14 by the first electrolytic cell 16 in which the rotating titanium drum 11 is used as a cathode and the DSA 14 is disposed on the lower side. An electrolytic copper foil 1 having a thickness of 6 μm was produced by passing an electric current between −DSA.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Hydroxyethyl cellulose = 1-30ppm
Low molecular weight gelatin (molecular weight 3,000) = 1-30ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
The roughness of the electrolytic deposition surface 102 of this copper foil 1 was Rz = 1.3 μm and Ra = 0.3 μm, and the roughness of the drum surface 101 was Rz = 1.6 μm and Ra = 0.4 μm.

　この銅箔１を第二ドラム１２に導き、ドラム面側を第一電解液と同じ電解液１８を用いて６μｍの銅電析を行い、１２μｍ箔２を得た。前記ドラム１０１面上に銅電析を行った面の粗さはＲｚ＝１．３μｍ、Ｒａ＝０．３μｍとなり、両面とも「電解析出面」の形状をした銅箔２を得ることができた。この銅箔の引張強さ＝３１０ＭＰａ、伸び＝８．０％であった。 The copper foil 1 was guided to the second drum 12, and 6 μm of copper electrodeposition was performed on the drum surface side using the same electrolytic solution 18 as the first electrolytic solution to obtain a 12 μm foil 2. The roughness of the surface where copper electrodeposition was performed on the surface of the drum 101 was Rz = 1.3 μm and Ra = 0.3 μm, and it was possible to obtain a copper foil 2 having the shape of an “electrolytically deposited surface” on both sides. . The copper foil had a tensile strength of 310 MPa and an elongation of 8.0%.

　なお、ＲｚはＪＩＳ　Ｂ　０６０１－１９９４に記載する十点平均粗さであり、ＲａはＪＩＳ　Ｂ　０６０１－１９９４に記載する算術平均粗さである。 Rz is the ten-point average roughness described in JIS B 0601-1994, and Ra is the arithmetic average roughness described in JIS B 0601-1994.

　次にこの銅箔を、三酸化クロム５ｇ／Ｌ溶液中で両面とも０．３Ａ／ｄｍ² 、１０秒間陰極電解し、水洗して乾燥させ、電池用電解銅箔とした。
　また、この電解銅箔の電子顕微鏡写真を撮り、図３（Ａ１）に第一ドラムによる電解析出面を、図３（Ａ２）に第一ドラムのドラム面上に第二ドラムによって銅を電解析出させた面を示した。
　銅箔の両面側ともに「電解析出面」の形状をしていることがわかる。 Next, this copper foil was subjected to cathodic electrolysis in a chromium trioxide 5 g / L solution on both sides at 0.3 A / dm ² for 10 seconds, washed with water and dried to obtain an electrolytic copper foil for a battery.
Also, an electron micrograph of this electrolytic copper foil is taken, and the electrolytic deposition surface by the first drum is shown in FIG. 3 (A1), and the copper is electroanalyzed by the second drum on the drum surface of the first drum in FIG. 3 (A2). Shown the raised surface.
It can be seen that both sides of the copper foil have an “electrolytic deposition surface” shape.

　一方、活物質については、平均粒子径１００ｎｍのケイ素系粒子を使用した。 On the other hand, for the active material, silicon-based particles having an average particle diameter of 100 nm were used.

　活物質７４％に、アセチレンブラック粉（ＡＢ）１６％、スチレンブタジエンコポリマー（ＳＢＲ）５％、カルボキシメチルセルロースナトリウム（ＣＭＣＮａ）５％に水を溶媒として、混合してスラリーを調製した。次いで、上記電解銅箔に上記スラリーを塗布し、塗工膜をほぼ均一なシートとし、乾燥し、プレス機で圧縮して集電体上に活物質層を密着接合させ、更に減圧乾燥させて試験電極（負極）を作製した。この後２０φに打ち抜き負極とした。 A slurry was prepared by mixing 74% active material, 16% acetylene black powder (AB), 5% styrene butadiene copolymer (SBR), 5% sodium carboxymethylcellulose (CMCNa) with water as a solvent. Next, the slurry is applied to the electrolytic copper foil, the coating film is made into a substantially uniform sheet, dried, compressed by a press machine to closely bond the active material layer on the current collector, and further dried under reduced pressure. A test electrode (negative electrode) was prepared. Thereafter, a negative electrode was punched out to 20φ.

　上記の電極を負極とし、金属リチウム箔を対極、及び参照極として、１．３モルのＬｉＰＦ₆／エチレンカーボネート（ＥＣ）＋エチルメチルカーボネート（ＥＭＣ）＋ジメチルカーボネート（ＤＭＣ）（ＥＣ：ＥＭＣ：ＤＭＣ＝２：５：３（体積比））溶液を電解液として、三極セルを作製した。
　この試験セルにおける負極の評価を次の方法により温度２５℃で行った。 1.3 mol of LiPF ₆ / ethylene carbonate (EC) + ethyl methyl carbonate (EMC) + dimethyl carbonate (DMC) (EC: EMC: DMC) using the above electrode as a negative electrode, a metal lithium foil as a counter electrode, and a reference electrode = 2: 5: 3 (volume ratio)) A triode cell was produced using the solution as an electrolyte.
The negative electrode in this test cell was evaluated at a temperature of 25 ° C. by the following method.

充放電試験方法；
Ｃレート算出
　試験極中の活物質量によりＣレートを以下の通りに算出した。
　　　Ｓｉ：１Ｃ＝４，０００ｍＡｈ／ｇ
初回条件
　充電：０．１Ｃ相当電流で定電流充電し、０．０２Ｖ（対Ｌｉ／Ｌｉ＋）到達後、定電位充電し、充電電流が０．０５Ｃ相当に低下した時点で終了した。
　放電：０．１Ｃ相当電流で定電流放電し、１．５Ｖになった時点で終了した。
充放電サイクル条件
　初回充放電試験を実施した後、同じ０．１Ｃ相当電流で１００サイクルまで充放電を繰り返した。 Charge / discharge test method;
C rate calculation The C rate was calculated as follows according to the amount of active material in the test electrode.
Si: 1C = 4,000 mAh / g
Initial condition charging: constant current charging at a current equivalent to 0.1 C, constant potential charging after reaching 0.02 V (vs. Li / Li +), and termination when charging current decreased to 0.05 C equivalent.
Discharge: A constant current was discharged at a current equivalent to 0.1 C, and the discharge was terminated when the voltage reached 1.5V.
Charging / discharging cycle conditions After conducting the initial charging / discharging test, charging / discharging was repeated up to 100 cycles at the same current equivalent to 0.1 C.

　この電解銅箔を負極集電体材料として用いた電極について、充放電１０サイクル、５０サイクル、１００サイクル後放電容量保持率を表１に示す。 Table 1 shows the discharge capacity retention after 10 cycles of charge / discharge, 50 cycles, and 100 cycles for an electrode using this electrolytic copper foil as a negative electrode current collector material.

　なお、サイクル後放電容量保持率は次式で示す。
（各サイクル後放電容量保持率％)＝[（各サイクル後の放電容量）／（最大放電容量）]×１００ The post-cycle discharge capacity retention rate is given by the following equation.
(Discharge capacity retention after each cycle%) = [(Discharge capacity after each cycle) / (Maximum discharge capacity)] × 100

＜実施例２＞
　実施例１と同じ条件で第一ドラムにより、１１μｍ厚さの電解銅箔を製造した。この銅箔を第二ドラムに導き、ドラム面側を第一ドラムと同じ電解液を用いて１μｍの銅電析を行い、１２μｍ箔を得た。
　この銅箔の電解析出面粗さはＲｚ＝１．２μｍ、Ｒａ＝０．３μｍ、ドラム面上に銅電析を行った面の粗さはＲｚ＝１．５μｍ、Ｒａ＝０．３μｍであった。この銅箔の引張強さ＝３１０ＭＰａ、伸び＝９．０％である。
　また、この電解銅箔の電子顕微鏡写真を撮り、図４（Ａ１）に第一ドラムによる電解析出面を、図４（Ａ２）に第一ドラムのドラム面上に第二ドラムによって銅を電解析出させた面を示した。 <Example 2>
An electrolytic copper foil having a thickness of 11 μm was produced using the first drum under the same conditions as in Example 1. This copper foil was guided to the second drum, and 1 μm of copper electrodeposition was performed on the drum surface side using the same electrolytic solution as that of the first drum to obtain a 12 μm foil.
The electrolytically deposited surface roughness of this copper foil was Rz = 1.2 μm, Ra = 0.3 μm, and the surface of the copper electrodeposited surface on the drum surface was Rz = 1.5 μm, Ra = 0.3 μm. It was. The copper foil has a tensile strength of 310 MPa and an elongation of 9.0%.
Also, an electron micrograph of this electrolytic copper foil is taken, and the electrolytic deposition surface by the first drum is shown in FIG. 4 (A1), and the copper is electroanalyzed by the second drum on the drum surface of the first drum in FIG. 4 (A2). Shown the raised surface.

　次にこの銅箔を水洗後、実施例１と同様にして三酸化クロム溶液中で両面とも陰極電解を行い、水洗後乾燥させ、電池集電体用電解銅箔とした。 Next, this copper foil was washed with water and then subjected to cathodic electrolysis on both sides in a chromium trioxide solution in the same manner as in Example 1, washed with water and dried to obtain an electrolytic copper foil for a battery current collector.

　この電解銅箔に実施例１と同じ活物質を塗布し、同じ方法で試験セルの作製と評価を行った。その結果を表１に併記する。 The same active material as in Example 1 was applied to this electrolytic copper foil, and a test cell was prepared and evaluated by the same method. The results are also shown in Table 1.

＜実施例３＞
　回転するチタンドラムを陰極として、その下側にＤＳＡを配置した第一ドラムにより、チタンドラムとＤＳＡの間に下記組成の硫酸銅－硫酸の電解液を流し、チタンドラム－ＤＳＡ間に電流を流して１１μｍ厚さの電解銅箔を製造した。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ヒドロキシエチルセルロース＝１～３０ｐｐｍ
　　低分子量ゼラチン（平均分子量３，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　この銅箔の電解析出面粗さはＲｚ＝１．２μｍ、Ｒａ＝０．３μｍ、ドラム面粗さはＲｚ＝１．４μｍ、Ｒａ＝０．４μｍであった。
　この銅箔を第二ドラムに導き、ドラム面側に第一ドラムとは異なる下記電解液を用いて１μｍの銅電析を行い、１２μｍ箔を得た。ドラム面上に銅電析を行った面の粗さはＲｚ＝１．１μｍ、Ｒａ＝０．２の粗さの両面とも「電解析出面」の形状をした銅箔を得ることができた。この銅箔の引張強さ＝３１０ＭＰａ、伸び＝８．０％である。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ポリエチレングリコール（平均分子量１，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　また、この電解銅箔の電子顕微鏡写真を撮り、図５（Ａ１）に第一ドラムによる電解析出面を、図５（Ａ２）に第一ドラムのドラム面上に第二ドラムによって銅を電解析出させた面を示した。 <Example 3>
A copper drum-sulfuric acid electrolyte having the following composition is passed between the titanium drum and the DSA, and a current is passed between the titanium drum and the DSA, with the rotating titanium drum serving as the cathode and a DSA disposed below the DSA. An electrolytic copper foil having a thickness of 11 μm was manufactured.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Hydroxyethyl cellulose = 1-30ppm
Low molecular weight gelatin (average molecular weight 3,000) = 1-30 ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
The electrolytic deposition surface roughness of this copper foil was Rz = 1.2 μm, Ra = 0.3 μm, and the drum surface roughness was Rz = 1.4 μm, Ra = 0.4 μm.
This copper foil was guided to the second drum, and 1 μm of copper electrodeposition was performed on the drum surface side using the following electrolytic solution different from the first drum to obtain a 12 μm foil. A copper foil in which the surface of the electrodeposited copper on the drum surface had the shape of an “electrolytically deposited surface” on both surfaces having a roughness of Rz = 1.1 μm and Ra = 0.2 could be obtained. The copper foil has a tensile strength of 310 MPa and an elongation of 8.0%.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Polyethylene glycol (average molecular weight 1,000) = 1-30ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
Also, an electron micrograph of this electrolytic copper foil is taken, and the electrolytic deposition surface by the first drum is shown in FIG. 5 (A1), and the copper is electroanalyzed by the second drum on the drum surface of the first drum in FIG. 5 (A2). Shown the raised surface.

　次にこの銅箔を水洗後、実施例１と同様にして三酸化クロム溶液中で両面とも陰極電解を行い、水洗後乾燥させ、電池用電解銅箔とした。 Next, after washing this copper foil with water, both sides were subjected to cathodic electrolysis in a chromium trioxide solution in the same manner as in Example 1, washed with water and dried to obtain an electrolytic copper foil for batteries.

＜実施例４＞
　回転するチタンドラムを陰極として、その下側にＤＳＡを配置した第一ドラムにより、チタンドラムとＤＳＡの間に下記組成の硫酸銅－硫酸の電解液を流し、チタンドラム－ＤＳＡ間に電流を流して１１μｍ厚さの電解銅箔を製造した。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ポリエチレングリコール（平均分子量１，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　この銅箔の電解析出面粗さはＲｚ＝１．２μｍ、Ｒａ＝０．３μｍ、ドラム面粗さはＲｚ＝１．８μｍ、Ｒａ＝０．４μｍであった。
　この銅箔を第二ドラムに導き、ドラム面側に第一ドラムとは異なる下記電解液を用いて１μｍの銅電析を行い、１２μｍ箔を得た。ドラム面上に銅電析を行った面の粗さはＲｚ＝１．５μｍ、Ｒａ＝０．２の粗さの両面とも「電解析出面」の形状をした銅箔を得ることができた。この銅箔の引張強さ＝３１０ＭＰａ、伸び＝８．０％である。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ヒドロキシエチルセルロース＝１～３０ｐｐｍ
　　低分子量ゼラチン（平均分子量３，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　また、この電解銅箔の電子顕微鏡写真を撮り、図６（Ａ１）に第一ドラムによる電解析出面を、図６（Ａ２）に第一ドラムのドラム面上に第二ドラムによって銅を電解析出させた面を示した。 <Example 4>
A copper drum-sulfuric acid electrolyte having the following composition is passed between the titanium drum and the DSA, and a current is passed between the titanium drum and the DSA, with the rotating titanium drum serving as the cathode and a DSA disposed below the DSA. An electrolytic copper foil having a thickness of 11 μm was manufactured.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Polyethylene glycol (average molecular weight 1,000) = 1-30ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
The electrolytic deposition surface roughness of this copper foil was Rz = 1.2 μm, Ra = 0.3 μm, and the drum surface roughness was Rz = 1.8 μm, Ra = 0.4 μm.
This copper foil was guided to the second drum, and 1 μm of copper electrodeposition was performed on the drum surface side using the following electrolytic solution different from the first drum to obtain a 12 μm foil. The surface of the drum electrode on which the copper electrodeposition was performed was able to obtain a copper foil having the shape of an “electrolytically deposited surface” on both surfaces with Rz = 1.5 μm and Ra = 0.2. The copper foil has a tensile strength of 310 MPa and an elongation of 8.0%.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Hydroxyethyl cellulose = 1-30ppm
Low molecular weight gelatin (average molecular weight 3,000) = 1-30 ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
Also, an electron micrograph of this electrolytic copper foil is taken, and the electrolytic deposition surface by the first drum is shown in FIG. 6 (A1), and the copper is electroanalyzed by the second drum on the drum surface of the first drum in FIG. 6 (A2). Shown the raised surface.

＜比較例1＞
　回転するチタンドラムを陰極として、その下側にＤＳＡを配置したドラムにより、チタンドラムとＤＳＡの間に下記組成の硫酸銅－硫酸の電解液を流し、チタンドラム－ＤＳＡ間に電流を流して１２μｍ厚さの電解銅箔を製造した。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ヒドロキシエチルセルロース＝１～３０ｐｐｍ
　　低分子量ゼラチン（分子量３，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　この銅箔の電解析出面粗さはＲｚ＝１．３μｍ、Ｒａ＝０．３μｍ、ドラム面粗さはＲｚ＝１．６μｍ、Ｒａ＝０．４μｍであった。
　この電解銅箔の電子顕微鏡写真を撮り、図７（Ｘ１）にドラム面を示した。 <Comparative Example 1>
Using a rotating titanium drum as a cathode and a drum with DSA disposed below it, a copper sulfate-sulfuric acid electrolyte solution having the following composition is passed between the titanium drum and the DSA, and a current is passed between the titanium drum and the DSA to 12 μm. Thick electrolytic copper foil was produced.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Hydroxyethyl cellulose = 1-30ppm
Low molecular weight gelatin (molecular weight 3,000) = 1-30ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
The electrolytic deposition surface roughness of this copper foil was Rz = 1.3 μm, Ra = 0.3 μm, and the drum surface roughness was Rz = 1.6 μm, Ra = 0.4 μm.
An electron micrograph of this electrolytic copper foil was taken, and the drum surface was shown in FIG. 7 (X1).

　この電解銅箔に実施例１と同じ活物質を塗布し、同じ方法で試験セルの作製と評価を行った。その結果を表１に併記した。 The same active material as in Example 1 was applied to this electrolytic copper foil, and a test cell was prepared and evaluated by the same method. The results are also shown in Table 1.

＜比較例２＞
　回転するチタンドラムを陰極として、その下側にＤＳＡを配置したドラムにより、チタンドラムとＤＳＡの間に下記組成の硫酸銅－硫酸の電解液を流し、チタンドラム－ＤＳＡ間に電流を流して１２μｍ厚さの電解銅箔を製造した。
電解液組成と電解条件；
　　Ｃｕ＝５０～１５０ｇ／Ｌ
　　Ｈ₂ＳＯ₄＝２０～２００ｇ／Ｌ
　　塩化物イオン＝１～６０ｐｐｍ
　　３－メルカプト－１－プロパンスルホン酸ナトリウム＝０．５～１０ｐｐｍ
　　ポリエチレングリコール（平均分子量１，０００）＝１～３０ｐｐｍ
　　温度＝３０～７０℃
　　電流密度：３０～１００Ａ／ｄｍ²
　この銅箔の電解析出面粗さはＲｚ＝１．３μｍ、Ｒａ＝０．３μｍ、ドラム面粗さはＲｚ＝１．８μｍ、Ｒａ＝０．４μｍであった。
　この電解銅箔の電子顕微鏡写真を撮り、図７（Ｙ１）にドラム面を示した。 <Comparative example 2>
Using a rotating titanium drum as a cathode and a drum with DSA disposed below it, a copper sulfate-sulfuric acid electrolyte having the following composition is passed between the titanium drum and DSA, and an electric current is passed between the titanium drum and DSA to 12 μm. Thick electrolytic copper foil was produced.
Electrolyte composition and electrolysis conditions;
Cu = 50 to 150 g / L
H ₂ SO ₄ = 20 to 200 g / L
Chloride ion = 1-60ppm
Sodium 3-mercapto-1-propanesulfonate = 0.5-10ppm
Polyethylene glycol (average molecular weight 1,000) = 1-30ppm
Temperature = 30-70 ° C
Current density: 30 to 100 A / dm ²
The electrolytic deposition surface roughness of this copper foil was Rz = 1.3 μm, Ra = 0.3 μm, and the drum surface roughness was Rz = 1.8 μm, Ra = 0.4 μm.
An electron micrograph of this electrolytic copper foil was taken, and the drum surface was shown in FIG. 7 (Y1).

　表１、図３～６に示すように本発明の実施例では銅箔の両表面ともに同様の表面形状を示し、該電解銅箔を集電体とし、負極電極を製造し、ＨＥＶ、ＥＶ、ＰＨＥＶといった自動車用のリチウムイオン二次電池としての電池性能を満足する優れたものであった。
　一方、比較例１、２はドラム面がそのまま活物質と接触しているため充放電効率が好ましくなく、ＨＥＶ、ＥＶ、ＰＨＥＶといった自動車用のリチウムイオン二次電池としては満足できない結果となっている。 As shown in Table 1 and FIGS. 3 to 6, in the examples of the present invention, both surfaces of the copper foil showed the same surface shape, the electrolytic copper foil was used as a current collector, a negative electrode was manufactured, HEV, EV, It was excellent in satisfying battery performance as a lithium ion secondary battery for automobiles such as PHEV.
On the other hand, in Comparative Examples 1 and 2, since the drum surface is in direct contact with the active material, the charge / discharge efficiency is not preferable, and the results are not satisfactory as lithium ion secondary batteries for automobiles such as HEV, EV, and PHEV. .

本件銅箔は二次電池用銅箔、特にリチウムイオン二次電池負極集電体用として有用である。 The present copper foil is useful as a secondary battery copper foil, particularly as a negative electrode current collector for a lithium ion secondary battery.

　　１１、１２　チタンドラム
　　１４　ＤＳＡ
　　１６　第一電解槽
　　１７　第二電解槽 11, 12 Titanium drum 14 DSA
16 First electrolytic cell 17 Second electrolytic cell

Claims

　正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池において、負極を構成する前記集電体は電解銅箔からなり、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織であるリチウムイオン二次電池。 In a lithium ion secondary battery comprising a positive electrode, a negative electrode in which an electrode constituent active material layer is formed on the surface of the current collector, and a non-aqueous electrolyte, the current collector constituting the negative electrode is made of an electrolytic copper foil. Both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposition surface is a lithium ion secondary battery having a granular crystal structure.
　正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池の前記負極を構成する集電体であって、該集電体は電解銅箔からなり、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織であるリチウムイオン二次電池用集電体。 A current collector constituting the negative electrode of a lithium ion secondary battery comprising a positive electrode, a negative electrode having an electrode-constituting active material layer formed on the surface of the current collector, and a non-aqueous electrolyte, The body is made of electrolytic copper foil, and both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposition surface is a current collector for a lithium ion secondary battery having a crystalline structure of granular crystals.
　正極と負極と非水電解液とを備えるリチウムイオン二次電池の前記負極集電体を構成する電解銅箔であって、該電解銅箔の両面は電解析出で形成され、該電解析出面は粒状晶の結晶組織であるリチウムイオン二次電池負極集電体用電解銅箔。 An electrolytic copper foil constituting the negative electrode current collector of a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, wherein both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposition surface Is an electrolytic copper foil for a negative electrode current collector of a lithium ion secondary battery, which has a granular crystal structure.
　正極及び集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池において、負極を構成する前記集電体は銅を電解析出して形成する電解銅箔であって、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面であるリチウムイオン二次電池。 In a lithium ion secondary battery comprising a negative electrode in which an electrode-constituting active material layer is formed on the surfaces of a positive electrode and a current collector and a non-aqueous electrolyte, the current collector constituting the negative electrode is formed by electrolytically depositing copper. An electrolytic copper foil to be formed, wherein the first surface of the electrolytic copper foil is a surface formed by copper electrodeposition of a granular crystal structure on the drum surface, and the second surface opposite to the first surface is The lithium ion secondary battery which is the surface formed by the copper electrodeposition of the crystal structure of a granular crystal on the back side of the 1st surface after film-forming of the 1st surface.
　正極と、集電体の表面に電極構成活物質層が形成されてなる負極と、非水電解液とを備えるリチウムイオン二次電池の前記二次電池を構成する負極集電体であって、該負極集電体は銅を電解析出して形成する電解銅箔であって、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面であるリチウムイオン二次電池用負極集電体。 A negative electrode current collector constituting the secondary battery of a lithium ion secondary battery comprising a positive electrode, a negative electrode in which an electrode-constituting active material layer is formed on the surface of the current collector, and a non-aqueous electrolyte, The negative electrode current collector is an electrolytic copper foil formed by electrolytic deposition of copper, and the first surface of the electrolytic copper foil is a surface formed by copper electrodeposition of a granular crystal structure on the drum surface; The second surface opposite to the first surface is a surface formed by copper electrodeposition of a granular crystal structure on the back side of the first surface after the first surface film formation. body.
　正極と負極と非水電解液とを備えるリチウムイオン二次電池の前記二次電池を構成する負極集電体用電解銅箔であって、該電解銅箔は銅を電解析出して形成する電解銅箔であって、該電解銅箔の第一表面はドラム面上に粒状晶の結晶組織の銅電析で形成した面であり、該第一表面と反対側の第二表面は、第一表面製膜後に、第一表面の裏側に粒状晶の結晶組織の銅電析で形成した面であるリチウムイオン二次電池負極集電体用電解銅箔。 An electrolytic copper foil for a negative electrode current collector constituting the secondary battery of a lithium ion secondary battery comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte, the electrolytic copper foil being formed by electrolytic deposition of copper A first surface of the electrolytic copper foil is a surface formed by copper electrodeposition of a granular crystal structure on a drum surface, and a second surface opposite to the first surface is a first surface An electrolytic copper foil for a negative electrode current collector for a lithium ion secondary battery, which is a surface formed by copper electrodeposition of a granular crystal structure on the back side of the first surface after surface film formation.