JP2015023009A - Laminated nonaqueous-electrolyte battery - Google Patents
Laminated nonaqueous-electrolyte battery Download PDFInfo
- Publication number
- JP2015023009A JP2015023009A JP2013153153A JP2013153153A JP2015023009A JP 2015023009 A JP2015023009 A JP 2015023009A JP 2013153153 A JP2013153153 A JP 2013153153A JP 2013153153 A JP2013153153 A JP 2013153153A JP 2015023009 A JP2015023009 A JP 2015023009A
- Authority
- JP
- Japan
- Prior art keywords
- electrode plate
- negative electrode
- positive electrode
- thickness
- current collector
- 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
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Cell Electrode Carriers And Collectors (AREA)
- Secondary Cells (AREA)
Abstract
Description
本発明は、非水電解液電池に係り、特に、正極活物質を含む正極活物質合剤層を有する正極と、負極活物質を含む負極活物質合剤層を有する負極とが非水電解液に浸潤された積層式非水電解液電池に関する。 The present invention relates to a nonaqueous electrolyte battery, and in particular, a positive electrode having a positive electrode active material mixture layer containing a positive electrode active material and a negative electrode having a negative electrode active material mixture layer containing a negative electrode active material. The present invention relates to a laminated non-aqueous electrolyte battery infiltrated into a battery.
リチウムイオン電池に代表される非水電解液電池は、高電圧・高エネルギー密度であり、かつ、貯蔵性能や低温作動性能に優れるため、電源の小型化や軽量化が可能となる。このため、広く民生用の携帯型電気製品に使用されている。また、携帯用の小型電源に止まらず、電気自動車用の電源や家庭用の夜間電力貯蔵装置、さらには、太陽光や風力などの自然エネルギーの有効活用、電力使用の平準化、無停電電源装置および建設機械に用いる産業用の電源についても開発が展開されている。特に、無停電電源装置用のリチウムイオン電池として、設置時の体積効率が高い積層式の大容量角形電池が開発されている。更に、無停電電源装置で短時間バックアップする用途では、大電流で放電する必要がある。そのような中、大容量化のために、電極の面積を大きく、積層枚数を多くしたり、高エネルギー密度化のため、電極に用いる集電箔を薄くしたり、高出力化のため電極の厚みを薄くし電極面積を大きくするといった電池の開発が進められている。 A non-aqueous electrolyte battery typified by a lithium ion battery has a high voltage and a high energy density, and is excellent in storage performance and low-temperature operation performance. Therefore, the power supply can be reduced in size and weight. For this reason, it is widely used in portable electric products for consumer use. In addition, not only small portable power sources, but also electric vehicle power sources and household nighttime power storage devices, as well as effective use of natural energy such as sunlight and wind power, leveling of power usage, uninterruptible power supply devices Development of industrial power sources used in construction machinery is also being developed. In particular, as a lithium ion battery for an uninterruptible power supply, a stacked large-capacity square battery with high volumetric efficiency at the time of installation has been developed. Furthermore, in applications where backup is performed for a short time with an uninterruptible power supply, it is necessary to discharge with a large current. Under such circumstances, to increase the capacity, the area of the electrode is increased, the number of stacked layers is increased, the current collecting foil used for the electrode is made thinner to increase the energy density, or the electrode is increased for higher output. Batteries are being developed to reduce the thickness and increase the electrode area.
ところが、積層式の大容量角形電池は、電極の大面積化、薄膜化で、正極板と負極板が対向し維持されるための強度が低下している。そのため、充放電に伴う電極の膨張収縮により、最外部の電極が変形し、正極と負極の対向面での圧力が不均一になることで、高出力時の容量劣化が大きくなるというおそれがある。特に、電極の面積を大きく、集電箔や電極の厚みを薄くした場合、その影響が大きくなると考えられる。 However, the strength of the stacked large-capacity prismatic battery is reduced because the positive electrode plate and the negative electrode plate are maintained facing each other as the electrode area is increased and the film thickness is reduced. For this reason, the outermost electrode is deformed by the expansion and contraction of the electrode due to charge and discharge, and the pressure on the opposing surfaces of the positive electrode and the negative electrode becomes non-uniform, which may increase the capacity deterioration at the time of high output. . In particular, when the area of the electrode is increased and the thickness of the current collector foil or the electrode is decreased, it is considered that the influence becomes larger.
このような事態を回避し電池の劣化を小さくするために、最外部の変形を抑制する方法として、金属プレートや樹脂プレートで固定するなど、種々の技術が提案されている。また、ゲル電解質を用いた電池においては、正極、負極とセパレータが接着されるため、前記課題を回避できる。しかしながら、ゲル電解質を用いた電池は、電解液を用いた電池に比べ、出力特性が低下してしまう。
前記課題を解決することと目的を異としているが、積層式電池において、電池内部に発生した熱を電池外部に放出し、寿命特性を向上するために、電極群の積層方向の内部に配置された極板を集電体の厚みが、電極群の積層方向の最外部に位置する最外部の極板を構成する集電体の厚みよりも小さくする技術が開示されている(特許文献1参照)。
In order to avoid such a situation and reduce deterioration of the battery, various techniques such as fixing with a metal plate or a resin plate have been proposed as a method for suppressing the outermost deformation. Moreover, in the battery using a gel electrolyte, since the positive electrode, the negative electrode, and the separator are bonded, the above problem can be avoided. However, the battery using the gel electrolyte has lower output characteristics than the battery using the electrolytic solution.
Although the purpose is different from solving the above problems, in a stacked battery, in order to release the heat generated inside the battery to the outside of the battery and improve the life characteristics, it is arranged inside the stacking direction of the electrode group. A technique is disclosed in which the thickness of the current collector is made smaller than the thickness of the current collector constituting the outermost electrode plate located at the outermost position in the stacking direction of the electrode group (see Patent Document 1). ).
しかしながら、特許文献1の技術は、熱の放出に関する技術で、電池の用途により電池内部に発生した熱による影響は異なってくる。本発明は電極群の歪みに対する強度向上の技術であるため、電極群の積層方向の内部に配置された極板を集電体の厚みが、電極群の積層方向の最外部に位置する最外部の極板を構成する集電体の厚みよりも大きくするものである。 However, the technique of Patent Document 1 is a technique related to heat release, and the influence of heat generated inside the battery differs depending on the use of the battery. Since the present invention is a technique for improving the strength against the distortion of the electrode group, the outermost electrode plate in which the thickness of the current collector is positioned at the outermost part of the electrode group in the stacking direction is arranged. The thickness of the current collector constituting the electrode plate is made larger.
大電流放電時の容量劣化が小さくなることは、電池の使用用途によっても要求度が異なっている。例えば、非常用電源の中でも、携帯電話の無線基地局での用途では要求度が小さいものの、無停電電源装置(UPS)の用途では重要な性能の1つとなる。従って、高率放電時の容量劣化を抑制することができれば、非水電解液電池の用途拡大ないし普及に期待することができる。 Reduction in capacity deterioration during large current discharge is different depending on the intended use of the battery. For example, among emergency power supplies, although the degree of demand is small for use in a radio base station of a mobile phone, it is one of important performances for use in an uninterruptible power supply (UPS). Therefore, if capacity degradation at the time of high rate discharge can be suppressed, it can be expected that the non-aqueous electrolyte battery will be used or expanded.
本発明は上記事案に鑑み、高エネルギー密度を確保しつつ高率放電におけるサイクル特性を向上させることができる積層式非水電解液電池を提供することを課題とする。 An object of the present invention is to provide a multilayer nonaqueous electrolyte battery capable of improving cycle characteristics in high rate discharge while ensuring a high energy density.
本発明の積層式非水電解液電池は、正極板及び負極板とセパレータとを備え、前記正極板及び前記負極板ともに、集電体の両面に活物質合剤からなる活物質合剤層を形成してなり、前記正極板と前記負極板とが交互にセパレータを介して複数積層してなる電極群と、前記正極板及び前記負極板の前記集電体の端部と接続された端子と、前記電極群に含浸された電解液とを有する積層式非水電解液電池において、前記電極群の正極板及び負極板の積層方向の最外部に配置された正極板及び負極板のうち少なくとも一つの正極板又は負極板の集電体の厚みが、前記電極群の正極板及び負極板の積層方向の内部に配置された正極板及び負極板の集電体の厚みよりも大きいことを特徴とする。 The multilayer nonaqueous electrolyte battery of the present invention includes a positive electrode plate, a negative electrode plate, and a separator, and both the positive electrode plate and the negative electrode plate have active material mixture layers made of an active material mixture on both sides of a current collector. An electrode group formed by alternately laminating the positive electrode plate and the negative electrode plate via separators, and a terminal connected to an end of the current collector of the positive electrode plate and the negative electrode plate, And a non-aqueous electrolyte battery having an electrolyte impregnated in the electrode group, wherein at least one of the positive electrode plate and the negative electrode plate arranged on the outermost part in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group. The thickness of the current collector of one positive electrode plate or the negative electrode plate is larger than the thickness of the current collector of the positive electrode plate and the negative electrode plate arranged in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group, To do.
最外部の正極板及び負極板の集電体の厚みを、内部の極板の集電体の厚みよりも大きくする。このため、最外部の正極板及び負極板の変形に対する強度が大きくなり、充放電による電極の変形が抑制され、寿命特性を向上することができる。 The thickness of the current collector of the outermost positive electrode plate and the negative electrode plate is made larger than the thickness of the current collector of the inner electrode plate. For this reason, the intensity | strength with respect to a deformation | transformation of an outermost positive electrode plate and a negative electrode plate becomes large, the deformation | transformation of the electrode by charging / discharging is suppressed, and a lifetime characteristic can be improved.
また、本発明の積層式非水電解液電池は、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板又は負極板の集電体の厚みの比が、1超3以下であることが好ましい。内部の正極板及び負極板の集電体の厚みに対する最外部の正極板又は負極板の集電体の厚みの比が3を超える場合には、電池のエネルギー密度が低下するおそれがあるからである。内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚みの比率の下限は好ましくは1超で、より好ましくは1.5以上、更には2以上がよい。 Further, in the laminated nonaqueous electrolyte battery of the present invention, the ratio of the thickness of the current collector of the outermost positive electrode plate or negative electrode plate to the thickness of the current collector of the positive electrode plate and the negative electrode plate is more than 1 and 3 or less. It is preferable that If the ratio of the thickness of the current collector of the outermost positive electrode plate or negative electrode plate to the thickness of the current collector of the inner positive electrode plate and the negative electrode plate exceeds 3, the energy density of the battery may decrease. is there. The lower limit of the ratio of the thickness of the current collector of the outermost positive electrode plate and the negative electrode plate to the thickness of the current collector of the inner positive electrode plate and the negative electrode plate is preferably more than 1, more preferably 1.5 or more, and further 2 The above is good.
また、本発明の積層式非水電解液電池は、電極群の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板又は負極板の集電体の数の比率が30%以下であることが好ましく、更には10〜20%であることが望ましい。内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率が30%を超える場合には、集電体の厚み変化による劣化抑制効果の向上は期待できず、エネルギー密度が低下してしまうおそれがある。 The multilayer nonaqueous electrolyte battery of the present invention has a thickness that is greater than the thickness of the current collectors of the positive electrode plate and the negative electrode plate when the total number of current collectors in the electrode group is 100%. The ratio of the number of current collectors on the outermost positive electrode plate or negative electrode plate to be increased is preferably 30% or less, and more preferably 10 to 20%. When the ratio of the number of current collectors on the outermost positive electrode plate and negative electrode plate that is larger than the thickness of the current collector on the inner positive electrode plate and the negative electrode plate exceeds 30%, the thickness change of the current collector The improvement of the deterioration suppression effect by cannot be expected, and the energy density may decrease.
本発明の積層式非水電解液電池によれば、電極群の積層方向の最外部の正極板及び負極板を構成する集電体の厚みが、電極群の積層方向の最内部の正極板及び負極板を構成する集電体の厚みよりも大きいため、最外部の正極板及び負極板の変形に対する強度が大きくなり、充放電による電極の変形が抑制され、寿命特性を向上することができる、という効果を奏することができる。また、高エネルギー密度を確保しつつ高率放電におけるサイクル特性を向上させることができる。 According to the multilayer nonaqueous electrolyte battery of the present invention, the outermost positive electrode plate in the stacking direction of the electrode group and the thickness of the current collector constituting the negative electrode plate are the innermost positive electrode plate in the stacking direction of the electrode group and Since it is larger than the thickness of the current collector constituting the negative electrode plate, the strength against deformation of the outermost positive electrode plate and negative electrode plate is increased, the deformation of the electrode due to charge and discharge is suppressed, and the life characteristics can be improved. The effect that can be produced. In addition, cycle characteristics in high rate discharge can be improved while ensuring a high energy density.
以下、図面を参照して本発明の実施の形態を詳細に説明する。図1は、本発明の実施の形態の一例のリチウムイオン二次電池1の概略縦断面図である。本実施の形態のリチウムイオン二次電池1は、電極群3と、電極群3を内部に収容するアルミニウムまたはアルミニウム合金により構成された角型電池容器5とを備えている。電極群3は、複数枚の負極板2と図示しない複数枚の正極板とがそれぞれ複数枚のセパレータ4を介して交互に積層されて構成されている。負極板2は、負極タブ2aを有しており、正極板は正極タブ6aを有している。
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a lithium ion secondary battery 1 as an example of an embodiment of the present invention. The lithium ion secondary battery 1 of the present embodiment includes an
アルミニウムまたはアルミニウム合金により構成された電池容器5は、一方の端部が開口する電池缶9と、電池蓋7とを備えており、電極群3を電池缶9に挿入した後、電池缶9の開口周縁部と、電池蓋7の周縁部とを溶接することで密閉されている。
電池蓋7には、アルミニウム製の正極端子11及び銅製の負極端子13が固定されている。正極端子11及び負極端子13は、電池蓋7に設けられた二つの貫通孔9a及び9bを貫通して電池容器5の外部に突出する端子部(出力端子)11a及び13aと、電池容器5内に配置される端子本体部11b及び13bとをそれぞれ有している。正極端子11及び負極端子13の端子部11a及び13aと電池蓋7の貫通孔9a及び9bとの間には、ガラス材料、ガラス−セラミック材料によって形成されたハーメチックシール部15a及び15bが設けられている。
A
A
電池蓋7には、図示していないが、ガス排出弁及び注液口が配設されている。ガス排出弁は、電池内圧上昇時にステンレス箔が開裂して内部のガスを放出する機能を有している。注液口からは、エチレンカーボネートのような環状カーボネートとジメチルカーボネートのような鎖状カーボネートとの混合溶媒に4フッ化ホウ酸リチウム(LiBF4)のリチウム塩を溶解した非水電解液17が注入されている。
Although not shown, the battery lid 7 is provided with a gas discharge valve and a liquid injection port. The gas discharge valve has a function of cleaving the stainless steel foil and releasing the internal gas when the battery internal pressure rises. From the injection port, a nonaqueous
正極端子11の端子本体部11bには、電極群3中の複数の正極板の正極タブ6aが超音波溶接またはレーザー溶接により取り付けられている。また、負極端子13の端子本体部13bには、複数の負極板2の負極タブ2aが超音波溶接またはレーザー溶接により取り付けられている。セパレータ4は、例えばリチウムイオンが通過可能なポリエチレン製の多孔質材によりほぼ長方形形状のシート状に形成されて、正極板と負極板2とが接触して短絡することを防止している。
A plurality of positive electrode tabs 6 a in the
正極タブ6aを有する正極板は、ほぼ長方形形状の板状に形成されたアルミニウム箔からなる正極板用の集電体と、正極板用の集電体の両面に設けられた正極活物質とを有している。正極活物質は、例えばリチウムマンガン複酸化物粉末と、導電材として鱗片状黒鉛と、結着剤としてポリフッ化ビニリデン(PVDF)とを質量比85:10:5の割合で混合し、これに分散溶媒のN−メチルピロリドン(NMP)を添加、混練したスラリを、正極板用の集電体に塗布した後、乾燥、プレスすることにより形成することができる。 The positive electrode plate having the positive electrode tab 6a includes a current collector for a positive electrode plate made of an aluminum foil formed in a substantially rectangular plate shape, and a positive electrode active material provided on both surfaces of the current collector for the positive electrode plate. Have. As the positive electrode active material, for example, lithium manganese complex oxide powder, scaly graphite as a conductive material, and polyvinylidene fluoride (PVDF) as a binder are mixed in a mass ratio of 85: 10: 5 and dispersed therein. A slurry obtained by adding and kneading N-methylpyrrolidone (NMP) as a solvent is applied to a current collector for a positive electrode plate, and then dried and pressed.
負極タブ2aを有する負極板2は、ほぼ長方形形状の板状に形成された電解銅箔からなる負極板用の集電体と、負極板用の集電体の両面に設けられた負極活物質とを有している。負極活物質は、例えば、非晶質炭素粉末90質量部に対し、結着剤としてポリフッ化ビニリデンを10質量部添加し、これに分散溶媒のNMPを添加、混練したスラリを、電解銅箔の両面に塗布した後乾燥、プレスすることにより形成することができる。電極群3の全体厚みは、積層数によるが、約30mmである。この試験では、容量が約50Ahになるように構成された電極群を用いた。
The
本実施形態の積層式非水電解液電池は、電極群の正極板及び負極板の積層方向の最外部に配置された正極板及び負極板のうち少なくとも一つの正極板又は負極板の集電体の厚みが、電極群の正極板及び負極板の積層方向の内部に配置された正極板及び負極板の集電体の厚みよりも大きい。
ここで、「電極群の正極板及び負極板の積層方向の最外部に配置された正極板及び負極板のうち少なくとも一つの正極板又は負極板」とは、電極群での正極板及び負極板の積層方向の両側の最も外部に位置する極板(正極板又は負極板を表す)のうち、積層方向の両側のそれぞれにおいて最外部の各1つの極板をいう。
「電極群の正極板及び負極板の積層方向の内部に配置された正極板及び負極板」とは、電極群の積層方向の最外部の極板よりも内側に配置された極板をいう。
The laminated nonaqueous electrolyte battery of the present embodiment is a current collector of at least one positive electrode plate or negative electrode plate among the positive electrode plate and the negative electrode plate arranged on the outermost side in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group. Is larger than the thickness of the current collector of the positive electrode plate and the negative electrode plate arranged in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group.
Here, “at least one positive electrode plate or negative electrode plate among the positive electrode plate and the negative electrode plate arranged on the outermost side in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group” means the positive electrode plate and the negative electrode plate in the electrode group Among the outermost electrode plates (representing a positive electrode plate or a negative electrode plate) on both sides in the stacking direction, the outermost one electrode plate on each of both sides in the stacking direction.
“The positive electrode plate and the negative electrode plate arranged in the stacking direction of the positive electrode plate and the negative electrode plate of the electrode group” refers to an electrode plate arranged inside the outermost electrode plate in the stacking direction of the electrode group.
内部の極板が複数存在する場合には、内部の極板の集電体の厚みは全て同一でもよく、異なっていてもよい。なお、異なっている場合は、内部の極板の集電体の厚みは、多段階的に変化させてもよい。
例えば、電極群の極板の積層数が3層である場合には、内部の極板は1層、集電体の厚みを厚くする最外部の極板は1層又は2層となる。また、極板の積層数が7層である場合には、内部の極板は5層、集電体の厚みを厚くする最外部の極板は1層又は2層となる。
例えば、内部の極板の集電体の厚みが30〜60μmである場合は、最外部の極板の2層のうちいずれか一つの極板の集電体の厚みが60μm超であればよい。
When there are a plurality of internal electrode plates, the current collectors of the internal electrode plates may all have the same thickness or different thicknesses. If they are different, the thickness of the current collector of the inner electrode plate may be changed in multiple steps.
For example, when the number of stacked electrode plates in the electrode group is 3, the inner electrode plate is one layer, and the outermost electrode plate that increases the thickness of the current collector is one or two layers. When the number of electrode plates is seven, the inner electrode plate is five layers, and the outermost electrode plate that increases the thickness of the current collector is one layer or two layers.
For example, when the thickness of the current collector of the inner electrode plate is 30 to 60 μm, the thickness of the current collector of any one of the two outermost electrode plates may be more than 60 μm. .
本実施形態の積層式非水電解液電池は、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板又は負極板の集電体の厚みの比は、1超3以下であることが好ましい。よって、例えば、内部の極板の集電体の厚みが30〜60μmである場合は、最外部の極板の2層のうちいずれか一つ極板の集電体の厚みは60μm超90μm以下が好ましい。例えば、内部の極板の集電体の厚みが30μmである場合は、最外部の極板の2層のうちいずれか一つの極板の集電体の厚みは30μm超90μm以下が好ましい。 In the laminated nonaqueous electrolyte battery of this embodiment, the ratio of the thickness of the current collector of the outermost positive electrode plate or negative electrode plate to the thickness of the current collector of the inner positive electrode plate and the negative electrode plate is more than 1 and 3 or less. Preferably there is. Therefore, for example, when the thickness of the current collector of the inner electrode plate is 30 to 60 μm, the current collector of any one of the two layers of the outermost electrode plate has a thickness of more than 60 μm and 90 μm or less. Is preferred. For example, when the thickness of the current collector of the inner electrode plate is 30 μm, the thickness of the current collector of any one of the two outermost electrode plates is preferably more than 30 μm and 90 μm or less.
本実施形態の積層式非水電解液電池は、電極群の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板又は負極板の集電体の数の比率が、30%以下であることがより好ましい。よって、例えば、極板の積層数が6層である場合には、内部の極板は4層であり、集電体の厚みを厚くする最外部の極板は1層が好ましい(17%)。また、例えば、極板の積層数が7層である場合には、内部の極板は5層であり、集電体の厚みを厚くする最外部の極板は2層でもよい(29%)。 The multilayer nonaqueous electrolyte battery of the present embodiment has a thickness larger than the thickness of the current collectors of the internal positive electrode plate and the negative electrode plate when the total number of current collectors in the electrode group is 100%. More preferably, the ratio of the number of current collectors on the outermost positive electrode plate or negative electrode plate is 30% or less. Thus, for example, when the number of electrode plates is six, the inner electrode plate is four layers, and the outermost electrode plate that increases the thickness of the current collector is preferably one layer (17%). . For example, when the number of stacked electrode plates is 7, the inner electrode plate may be five layers, and the outermost electrode plate that increases the thickness of the current collector may be two layers (29%). .
(実施例1)
すべての最外部の正極板及び負極板の集電体の厚みを60μmとし、すべての内部の正極板及び負極板の集電体の厚みを30μmとし、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率は2となるようにした。
なお、正極板の集電体は、アルミニウム箔であり、負極板の集電体は、電解銅箔である。
Example 1
The thicknesses of the current collectors of all the outermost positive and negative electrode plates are 60 μm, the current collectors of all the positive and negative electrode plates are 30 μm, and the current collectors of the inner positive and negative electrode plates The thickness ratio of the current collector of the outermost positive electrode plate and negative electrode plate to the thickness of the electrode was set to 2.
The current collector of the positive electrode plate is an aluminum foil, and the current collector of the negative electrode plate is an electrolytic copper foil.
なお、すべての正極板を構成している活物質合剤層の厚みは同じであり、また、すべての負極板を構成している活物質合剤層の厚みも同じである。例えば正極板の活物質合剤層の厚みは60μmであり、負極板の活物質合剤層の厚みは30μmである。
また、前記正極板の活物質合剤層を形成した活物質合剤は、リチウムマンガン複酸化物粉末と、導電材として鱗片状黒鉛と、結着剤としてポリフッ化ビニリデン(PVDF)とを質量比85:10:5の割合で混合し、これに分散溶媒のN−メチルピロリドン(NMP)を添加、混練したスラリである。
また、前記負極板の活物質合剤層を形成した活物質合剤は、非晶質炭素粉末90質量部に対し、結着剤としてポリフッ化ビニリデンを10質量部添加し、これに分散溶媒のNMPを添加、混練したスラリである。
In addition, the thickness of the active material mixture layer which comprises all the positive electrode plates is the same, and the thickness of the active material mixture layer which comprises all the negative electrode plates is also the same. For example, the thickness of the active material mixture layer of the positive electrode plate is 60 μm, and the thickness of the active material mixture layer of the negative electrode plate is 30 μm.
The active material mixture forming the active material mixture layer of the positive electrode plate is a mass ratio of lithium manganese complex oxide powder, scaly graphite as a conductive material, and polyvinylidene fluoride (PVDF) as a binder. It is a slurry obtained by mixing at a ratio of 85: 10: 5 and adding and kneading the dispersion solvent N-methylpyrrolidone (NMP) thereto.
The active material mixture in which the active material mixture layer of the negative electrode plate is added is 10 parts by mass of polyvinylidene fluoride as a binder with respect to 90 parts by mass of the amorphous carbon powder, and the dispersion solvent A slurry in which NMP is added and kneaded.
電極群3の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率を20%とし、電池を作製した。
すなわち、電極群において、集電体の厚みが30μmの内部の正極板及び負極板は8層であり、集電体の厚みが60μmの最外部の正極板及び負極板は2層である。
Current collector of the outermost positive electrode plate and negative electrode plate having a thickness larger than the thickness of the current collectors of the positive electrode plate and negative electrode plate inside when the number of all current collectors in
That is, in the electrode group, the inner positive electrode plate and the negative electrode plate having a current collector thickness of 30 μm are eight layers, and the outermost positive electrode plate and negative electrode plate having a current collector thickness of 60 μm are two layers.
(比較例1)
すべての正極板及び負極板の集電体の厚みを30μmとした以外は、実施例1と同様に電池を作製した。
(Comparative Example 1)
A battery was produced in the same manner as in Example 1 except that the thickness of the current collectors of all the positive and negative electrode plates was 30 μm.
(比較例2)
実施例1の最外部で正極板及び負極板の集電体厚みが大きくなった合計厚みに対して、半分の厚みのステンレススチールプレートを比較例1の電極群の両面に固定し、充放電による最外部の電極の変形が抑制できるようにした以外は、比較例1と同様に電池を作製した。本試験においては、0.35mmの厚みで負極板と同じ寸法のステンレススチールプレートを用いた。
(Comparative Example 2)
A stainless steel plate having a half thickness is fixed to both surfaces of the electrode group of Comparative Example 1 with respect to the total thickness in which the current collector thickness of the positive electrode plate and the negative electrode plate is increased at the outermost part of Example 1, and charging and discharging are performed. A battery was fabricated in the same manner as in Comparative Example 1, except that the deformation of the outermost electrode could be suppressed. In this test, a stainless steel plate having a thickness of 0.35 mm and the same dimensions as the negative electrode plate was used.
(比較例3)
比較例2でステンレススチールプレートの代わりにポリプロピレン製のプレートを用いた以外は、比較例2と同様に電池を作製した。
(Comparative Example 3)
A battery was prepared in the same manner as in Comparative Example 2 except that a polypropylene plate was used instead of the stainless steel plate in Comparative Example 2.
実施例1及び比較例1から3の電池において、充放電サイクル試験を行った結果を図2に示す。放電電流は、5CA(250A)で、充放電ともに25℃の温度環境下で行った。比較例1に比べて、最外部の変形を抑制した比較例2及び3では、サイクル特性の5CA放電容量維持率の改善は見られるが、最外部だけの固定となるため、充放電による最外部の変形を十分に抑制できない。一方、実施例1においては、最外部の20%の電極で固定されていることになるため、容量劣化を抑制する効果が発現したものと考えられる。 FIG. 2 shows the results of a charge / discharge cycle test performed on the batteries of Example 1 and Comparative Examples 1 to 3. The discharge current was 5 CA (250 A), and both charging and discharging were performed in a temperature environment of 25 ° C. In Comparative Examples 2 and 3 in which the outermost deformation is suppressed as compared with Comparative Example 1, the improvement in the 5CA discharge capacity retention rate of the cycle characteristics is seen, but since the outermost is fixed only, the outermost due to charge / discharge Cannot be sufficiently suppressed. On the other hand, in Example 1, since it is fixed by the outermost 20% electrode, it is considered that the effect of suppressing the capacity deterioration was expressed.
(実施例2)
実施例1の最外部の正極板及び負極板の集電体の厚みを60μmから45μmとし、内部の正極板及び負極板の集電体の厚みを30μmとし、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率を2から1.5にした。
電極群3の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率を20%とし、電池を作製した。
すなわち、電極群において、集電体の厚みが30μmの内部の正極板及び負極板は8層であり、集電体の厚みが45μmの最外部の正極板及び負極板は2層である。
(Example 2)
The thickness of the current collectors of the outermost positive electrode plate and negative electrode plate in Example 1 was set to 60 μm to 45 μm, the thickness of the current collectors of the internal positive electrode plate and negative electrode plate was set to 30 μm, and The thickness ratio of the current collector of the outermost positive electrode plate and negative electrode plate to the thickness of the electric current body was set to 2 to 1.5.
Current collector of the outermost positive electrode plate and negative electrode plate having a thickness larger than the thickness of the current collectors of the positive electrode plate and negative electrode plate inside when the number of all current collectors in
That is, in the electrode group, the inner positive electrode plate and the negative electrode plate having a current collector thickness of 30 μm are eight layers, and the outermost positive electrode plate and negative electrode plate having a current collector thickness of 45 μm are two layers.
(実施例3)
実施例1の最外部の正極板及び負極板の集電体の厚みを60μmから90μmとし、内部の正極板及び負極板の集電体の厚みを30μmとし、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率を2から3にした。
電極群3の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率を20%とし、電池を作製した。
すなわち、電極群において、集電体の厚みが30μmの内部の正極板及び負極板は8層であり、集電体の厚みが90μmの最外部の正極板及び負極板は2層である。
Example 3
The thickness of the current collectors of the outermost positive electrode plate and the negative electrode plate of Example 1 is set to 60 μm to 90 μm, the thickness of the current collector of the inner positive electrode plate and the negative electrode plate is set to 30 μm, and the current collector of the inner positive electrode plate and the negative electrode plate is collected. The thickness ratio of the current collectors of the outermost positive electrode plate and negative electrode plate with respect to the thickness of the electric body was changed from 2 to 3.
Current collector of the outermost positive electrode plate and negative electrode plate having a thickness larger than the thickness of the current collectors of the positive electrode plate and negative electrode plate inside when the number of all current collectors in
That is, in the electrode group, the inner positive electrode plate and negative electrode plate with a current collector thickness of 30 μm are eight layers, and the outermost positive electrode plate and negative electrode plate with a current collector thickness of 90 μm are two layers.
比較例1及び実施例1から3の電池において、充放電サイクル試験を行った結果を図3に示す。放電電流は、5CA(250A)で、充放電ともに25℃の温度環境下で行った。比較例1に比べて、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率を大きくすることで、サイクル特性は向上した。しかしながら、前記集電体の厚み比率を2以上にしても、改善の効果は見られない。逆に、集電箔の体積が大きくなるため、電池容量として寄与しない部分が大きくなり、エネルギー密度の低下につながる。また、集電箔の重量も大きくなるため、集電体の厚み比率を3以上では、電池特性として不利な条件となる。 FIG. 3 shows the results of a charge / discharge cycle test performed on the batteries of Comparative Example 1 and Examples 1 to 3. The discharge current was 5 CA (250 A), and both charging and discharging were performed in a temperature environment of 25 ° C. Compared with Comparative Example 1, the cycle characteristics were improved by increasing the thickness ratio of the current collector of the outermost positive electrode plate and the negative electrode plate to the thickness of the current collector of the inner positive electrode plate and the negative electrode plate. However, even if the thickness ratio of the current collector is 2 or more, no improvement effect is observed. Conversely, since the volume of the current collector foil increases, the portion that does not contribute to the battery capacity increases, leading to a decrease in energy density. In addition, since the weight of the current collector foil is increased, when the thickness ratio of the current collector is 3 or more, the battery characteristics are disadvantageous.
(実施例4)
すべての最外部の正極板及び負極板の集電体の厚みを60μmとし、すべての内部の正極板及び負極板の集電体の厚みを30μmとし、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率を2にした。
電極群3の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率を20%から10%とした以外は、実施例1と同様に電池を作製した。
すなわち、電極群において、集電体の厚みが30μmの内部の正極板及び負極板は18層であり、集電体の厚みが60μmの最外部の正極板及び負極板は2層である。
Example 4
The thicknesses of the current collectors of all the outermost positive and negative electrode plates are 60 μm, the current collectors of all the positive and negative electrode plates are 30 μm, and the current collectors of the inner positive and negative electrode plates The thickness ratio of the current collector of the outermost positive electrode plate and negative electrode plate to the thickness of 2 was set to 2.
Current collector of the outermost positive electrode plate and negative electrode plate having a thickness larger than the thickness of the current collectors of the positive electrode plate and negative electrode plate inside when the number of all current collectors in
That is, in the electrode group, the inner positive electrode plate and negative electrode plate with a current collector thickness of 30 μm are 18 layers, and the outermost positive electrode plate and negative electrode plate with a current collector thickness of 60 μm are two layers.
(実施例5)
すべての最外部の正極板及び負極板の集電体の厚みを60μmとし、すべての内部の正極板及び負極板の集電体の厚みを30μmとし、内部の正極板及び負極板の集電体の厚みに対する最外部の正極板及び負極板の集電体の厚み比率を2にした。
電極群3の中の集電体全体の数を100%としたときに、内部の正極板及び負極板の集電体の厚みよりも厚みを大きくする最外部の正極板及び負極板の集電体の数の比率を20%から29%とした以外は、実施例1と同様に電池を作製した。
すなわち、電極群において、集電体の厚みが30μmの内部の正極板及び負極板は5層であり、集電体の厚みが60μmの最外部の正極板及び負極板は2層である。
(Example 5)
The thicknesses of the current collectors of all the outermost positive and negative electrode plates are 60 μm, the current collectors of all the positive and negative electrode plates are 30 μm, and the current collectors of the inner positive and negative electrode plates The thickness ratio of the current collector of the outermost positive electrode plate and negative electrode plate to the thickness of 2 was set to 2.
Current collector of the outermost positive electrode plate and negative electrode plate having a thickness larger than the thickness of the current collectors of the positive electrode plate and negative electrode plate inside when the number of all current collectors in
That is, in the electrode group, the inner positive electrode plate and negative electrode plate having a current collector thickness of 30 μm are five layers, and the outermost positive electrode plate and negative electrode plate having a current collector thickness of 60 μm are two layers.
比較例1及び実施例1、4、5の電池において、充放電サイクル試験を行った結果を図4に示す。放電電流は、5CA(250A)で、充放電ともに25℃の温度環境下で行った。比較例1に比べて、最外部の正極板及び負極板の集電体の数と内部の正極板及び負極板の集電体の数の比率を大きくすることで、サイクル特性は向上した。しかしながら、最外部の正極板及び負極板の集電体の数と内部の正極板及び負極板の集電体の数の比率を20%以上にしても、改善の効果は小さい。逆に、集電箔の体積が大きくなるため、電池容量として寄与しない部分が大きくなり、エネルギー密度の低下につながる。また、集電箔の重量も大きくなるため、最外部の正極板及び負極板の集電体の数と内部の正極板及び負極板の集電体の数の比率を30%以上にした場合、電池特性として不利な条件となる。 FIG. 4 shows the results of a charge / discharge cycle test performed on the batteries of Comparative Example 1 and Examples 1, 4, and 5. The discharge current was 5 CA (250 A), and both charging and discharging were performed in a temperature environment of 25 ° C. Compared to Comparative Example 1, the cycle characteristics were improved by increasing the ratio of the number of current collectors on the outermost positive and negative electrode plates to the number of current collectors on the inner positive and negative electrode plates. However, even if the ratio of the number of current collectors on the outermost positive electrode plate and negative electrode plate to the number of current collectors on the inner positive electrode plate and negative electrode plate is 20% or more, the improvement effect is small. Conversely, since the volume of the current collector foil increases, the portion that does not contribute to the battery capacity increases, leading to a decrease in energy density. Also, since the weight of the current collector foil also increases, when the ratio of the number of current collectors of the outermost positive electrode plate and negative electrode plate and the number of current collectors of the inner positive electrode plate and negative electrode plate is 30% or more, This is a disadvantageous condition for battery characteristics.
本発明は、高エネルギー密度を確保しつつ高率放電時の寿命特性を向上させることができる非水電解液電池を提供するものであるため、非水電解液電池の製造、販売に寄与するので、産業上の利用可能性を有する。 Since the present invention provides a nonaqueous electrolyte battery that can improve the life characteristics during high rate discharge while ensuring a high energy density, it contributes to the manufacture and sale of nonaqueous electrolyte batteries. Have industrial applicability.
1 リチウムイオン二次電池
2 負極板
2a 負極タブ
3 電極群
4 セパレータ
5 角型電池容器
6a 正極タブ
7 電池蓋
9 電池缶
9a及び9b 貫通孔
11 正極端子
13 負極端子
11a及び13a 端子部
11b及び13b 端子本体部
15a及び15a ハーメチックシール部
17 非水電解液
DESCRIPTION OF SYMBOLS 1 Lithium ion
Claims (3)
前記電極群の正極板及び負極板の積層方向の最外部に配置された正極板及び負極板のうち少なくとも一つの正極板又は負極板の集電体の厚みが、前記電極群の正極板及び負極板の積層方向の内部に配置された正極板及び負極板の集電体の厚みよりも大きいことを特徴とする積層式非水電解液電池。 A positive electrode plate, a negative electrode plate, and a separator, wherein both the positive electrode plate and the negative electrode plate are formed with active material mixture layers made of an active material mixture on both sides of a current collector; A plurality of electrode groups alternately stacked via separators, terminals connected to the ends of the current collectors of the positive electrode plate and the negative electrode plate, and an electrolyte impregnated in the electrode group In a laminated nonaqueous electrolyte battery having
The thickness of the current collector of at least one positive electrode plate or negative electrode plate among the positive electrode plate and negative electrode plate arranged on the outermost side in the stacking direction of the positive electrode plate and negative electrode plate of the electrode group is the positive electrode plate and negative electrode of the electrode group A laminated non-aqueous electrolyte battery characterized in that the thickness is larger than the thickness of a current collector of a positive electrode plate and a negative electrode plate arranged in the lamination direction of the plates.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013153153A JP2015023009A (en) | 2013-07-24 | 2013-07-24 | Laminated nonaqueous-electrolyte battery |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013153153A JP2015023009A (en) | 2013-07-24 | 2013-07-24 | Laminated nonaqueous-electrolyte battery |
Publications (1)
Publication Number | Publication Date |
---|---|
JP2015023009A true JP2015023009A (en) | 2015-02-02 |
Family
ID=52487265
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2013153153A Pending JP2015023009A (en) | 2013-07-24 | 2013-07-24 | Laminated nonaqueous-electrolyte battery |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2015023009A (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002110170A (en) * | 2000-09-29 | 2002-04-12 | Mitsubishi Chemicals Corp | Battery |
JP2004139775A (en) * | 2002-10-16 | 2004-05-13 | Nissan Motor Co Ltd | Laminated battery, battery pack and vehicle |
JP2005005163A (en) * | 2003-06-12 | 2005-01-06 | Nissan Motor Co Ltd | Bipolar battery |
JP2007149349A (en) * | 2005-11-24 | 2007-06-14 | Nec Tokin Corp | Laminated battery |
JP2013191389A (en) * | 2012-03-13 | 2013-09-26 | Nissan Motor Co Ltd | Lamination structure cell |
-
2013
- 2013-07-24 JP JP2013153153A patent/JP2015023009A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002110170A (en) * | 2000-09-29 | 2002-04-12 | Mitsubishi Chemicals Corp | Battery |
JP2004139775A (en) * | 2002-10-16 | 2004-05-13 | Nissan Motor Co Ltd | Laminated battery, battery pack and vehicle |
JP2005005163A (en) * | 2003-06-12 | 2005-01-06 | Nissan Motor Co Ltd | Bipolar battery |
JP2007149349A (en) * | 2005-11-24 | 2007-06-14 | Nec Tokin Corp | Laminated battery |
JP2013191389A (en) * | 2012-03-13 | 2013-09-26 | Nissan Motor Co Ltd | Lamination structure cell |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10056577B2 (en) | Battery cell of novel structure | |
KR101379957B1 (en) | A Stepwise Electrode Assembly, and a Battery Cell, Battery Pack and Device Comprising the Same | |
JP5281629B2 (en) | Electrode assembly and secondary battery | |
KR101664244B1 (en) | Method forming electrode surface pattern and the electrode manufactured by the method and secondary battery including the same | |
KR20130118762A (en) | Electrode assembly, battery cell and device comprising the same | |
JP2010113966A (en) | Lithium secondary cell and its utilization | |
EP2302717A1 (en) | Electrode assembly for a rechargeable battery | |
JP2012089415A (en) | Secondary battery and battery pack | |
JP5552398B2 (en) | Lithium ion battery | |
CN208298952U (en) | Battery and electronic equipment | |
KR20180058370A (en) | Electrode Assembly Comprising Separator Having Insulation-enhancing Part Formed on Edge Portion of Electrode | |
KR101515672B1 (en) | Electrode assembly including anode and cathod electrode more than 2 and electrochemical device using the same | |
JP5838073B2 (en) | Cylindrical wound battery | |
KR102108113B1 (en) | Electrode Assembly Comprising Separator Having Folded Edge | |
JP2010015852A (en) | Secondary battery | |
KR101135492B1 (en) | Electrode assembly, and rechargeable battery using thereof | |
JP7365566B2 (en) | Non-aqueous electrolyte secondary battery | |
US9437898B2 (en) | Secondary battery including plurality of electrode assemblies | |
JP2006134697A (en) | Lithium-ion rechargeable battery | |
CN109478692B (en) | Electrode assembly including electrode leads coupled to long sides thereof | |
KR101491060B1 (en) | Secondary battery and battery pack including the same | |
JP2015023009A (en) | Laminated nonaqueous-electrolyte battery | |
JP2011216685A (en) | Composite electricity storage device | |
JP2015115203A (en) | Battery pack using laminate type battery | |
JP4334388B2 (en) | Non-aqueous electrolyte battery |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
RD02 | Notification of acceptance of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7422 Effective date: 20150421 |
|
A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20160206 |
|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20160629 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20170608 |
|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20171207 |