JP2020017398A - Power storage element - Google Patents
Power storage element Download PDFInfo
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- JP2020017398A JP2020017398A JP2018139226A JP2018139226A JP2020017398A JP 2020017398 A JP2020017398 A JP 2020017398A JP 2018139226 A JP2018139226 A JP 2018139226A JP 2018139226 A JP2018139226 A JP 2018139226A JP 2020017398 A JP2020017398 A JP 2020017398A
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- Prior art keywords
- positive electrode
- negative electrode
- power storage
- active material
- adhesive layer
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- 229920006255 plastic film Polymers 0.000 claims abstract description 18
- 239000007773 negative electrode material Substances 0.000 claims description 32
- 239000007774 positive electrode material Substances 0.000 claims description 32
- 239000011230 binding agent Substances 0.000 claims description 20
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- 229920005569 poly(vinylidene fluoride-co-hexafluoropropylene) Polymers 0.000 claims description 9
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- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
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- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 5
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- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- NDPGDHBNXZOBJS-UHFFFAOYSA-N aluminum lithium cobalt(2+) nickel(2+) oxygen(2-) Chemical compound [Li+].[O--].[O--].[O--].[O--].[Al+3].[Co++].[Ni++] NDPGDHBNXZOBJS-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
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- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 229910021450 lithium metal oxide Inorganic materials 0.000 description 2
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- 229910052719 titanium Inorganic materials 0.000 description 2
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- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
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- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- RQQRTMXCTVKCEK-UHFFFAOYSA-N [Ta].[Mg] Chemical compound [Ta].[Mg] RQQRTMXCTVKCEK-UHFFFAOYSA-N 0.000 description 1
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- UORVGPXVDQYIDP-UHFFFAOYSA-N borane Chemical class B UORVGPXVDQYIDP-UHFFFAOYSA-N 0.000 description 1
- QHIWVLPBUQWDMQ-UHFFFAOYSA-N butyl prop-2-enoate;methyl 2-methylprop-2-enoate;prop-2-enoic acid Chemical compound OC(=O)C=C.COC(=O)C(C)=C.CCCCOC(=O)C=C QHIWVLPBUQWDMQ-UHFFFAOYSA-N 0.000 description 1
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- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
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- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 238000007731 hot pressing Methods 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
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- 229920000092 linear low density polyethylene Polymers 0.000 description 1
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- DEUISMFZZMAAOJ-UHFFFAOYSA-N lithium dihydrogen borate oxalic acid Chemical compound B([O-])(O)O.C(C(=O)O)(=O)O.C(C(=O)O)(=O)O.[Li+] DEUISMFZZMAAOJ-UHFFFAOYSA-N 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- NEKSMZUJCUEYAR-UHFFFAOYSA-M lithium;2-methyl-2-(prop-2-enoylamino)propane-1-sulfonate Chemical compound [Li+].[O-]S(=O)(=O)CC(C)(C)NC(=O)C=C NEKSMZUJCUEYAR-UHFFFAOYSA-M 0.000 description 1
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- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- RHDUVDHGVHBHCL-UHFFFAOYSA-N niobium tantalum Chemical compound [Nb].[Ta] RHDUVDHGVHBHCL-UHFFFAOYSA-N 0.000 description 1
- URLJKFSTXLNXLG-UHFFFAOYSA-N niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Nb+5].[Nb+5] URLJKFSTXLNXLG-UHFFFAOYSA-N 0.000 description 1
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- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000011242 organic-inorganic particle Substances 0.000 description 1
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 1
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- 235000012239 silicon dioxide Nutrition 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
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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
- Secondary Cells (AREA)
- Electric Double-Layer Capacitors Or The Like (AREA)
- Sealing Battery Cases Or Jackets (AREA)
Abstract
Description
本発明は、ラミネート外装体を備える蓄電素子に関する。 The present invention relates to a power storage device including a laminate exterior body.
リチウムイオン二次電池等の蓄電素子は、電力貯蔵用の大型定置用電源、電気自動車用等の電源として利用されており、近年では電池の小型化及び薄型化の研究が進展している。蓄電素子は、金属箔の表面に電極活物質層を形成した両電極（正極及び負極）と、両電極の間に配置されるセパレータを備える電極体を用いることが一般的である。セパレータは、両電極間の短絡防止や電解液を保持する役割を果たす。 Power storage elements such as lithium ion secondary batteries are used as large stationary power supplies for power storage, power supplies for electric vehicles, and the like. In recent years, research into miniaturization and thinning of batteries has been advanced. An energy storage element generally uses an electrode body including both electrodes (a positive electrode and a negative electrode) each having an electrode active material layer formed on a surface of a metal foil and a separator disposed between the two electrodes. The separator plays a role in preventing a short circuit between the two electrodes and holding the electrolytic solution.
このような蓄電素子として、小型化及び軽量化の観点、並びに外気の侵入防止及び長期間にわたり高い電池性能を維持する観点から、ラミネートフィルム外装体の中に電極体を封入したものが提案されている（特許文献１）。ラミネート外装体は、一般的には、アルミニウムなどの金属層の両面にプラスチックフィルム層が積層及びラミネートされた積層フィルムで形成されている。 As such a power storage device, a device in which an electrode body is sealed in a laminate film exterior body has been proposed from the viewpoint of miniaturization and weight reduction, and from the viewpoint of preventing intrusion of outside air and maintaining high battery performance for a long period of time. (Patent Document 1). The laminate exterior body is generally formed of a laminated film in which a plastic film layer is laminated and laminated on both sides of a metal layer such as aluminum.
蓄電素子は、例えば、ラミネートフィルム外装体の周縁をヒートシールなどにより溶着することにより、電極体がその内部に封入されている。フィルムの周縁を溶着する際には、フィルム同士が熱により溶着された溶着部が生じ、該溶着部の幅が短すぎると、外部応力が生じた際に、溶着部が剥がれやすくなり、外装体としての機能を果たせなくなる。
一方で、溶着部の幅を長くすると、溶着部は剥がれ難くなるものの、ラミネート外装体の内部に封入する電極体のサイズを小さくする必要が生じ、そのため電極体の容量が低くなり、さらに電極体の形状選択の自由度が低下するという問題が生じる。
そこで、本発明は、ラミネート外装体の溶着部の幅を短くしつつ、外部応力が生じた場合に、溶着部が剥がれにくい蓄電素子を提供することを課題とする。
In the electric storage element, for example, an electrode body is sealed inside by welding the periphery of a laminate film exterior body by heat sealing or the like. When welding the periphery of the film, a welded portion where the films are welded by heat is generated. If the width of the welded portion is too short, the welded portion is easily peeled off when external stress occurs, and Function cannot be performed.
On the other hand, if the width of the welded portion is increased, the welded portion is less likely to be peeled off, but it is necessary to reduce the size of the electrode body sealed in the inside of the laminate exterior body. However, there is a problem that the degree of freedom in selecting the shape of the image is reduced.
Therefore, an object of the present invention is to provide a power storage element in which the welded portion is less likely to be peeled off when external stress is generated, while reducing the width of the welded portion of the laminate exterior body.
本発明者らは、鋭意検討の結果、電極体として、正極と、負極と、該正極と負極との間に配置される接着層とを備える電極体を用い、かつ該電極体を封入するラミネート外装体の周縁の溶着部の幅を一定範囲とすることで、上記課題を解決できることを見出し、以下の本発明を完成させた。本発明の要旨は、以下の［１］〜［９］である。
［１］内面層としてプラスチックフィルムを備えるラミネート外装体に、電極体が収容されている蓄電素子であって、前記電極体が、正極と、負極と、前記正極と負極との間に配置される接着層とを備えており、前記ラミネート外装体の周縁には、プラスチックフィルム同士が溶着された溶着部が設けられており、前記溶着部の幅が、ラミネート外装体の長手方向の長さの０．００８〜０．０６倍である、蓄電素子。
［２］前記接着層はバインダーを含有し、バインダーの含有量が前記接着層の全体積に対して３０〜８０体積％である、上記［１］に記載の蓄電素子。
［３］前記電極体が、正極活物質層を有する正極と、負極活物質層を有する負極と、正極と負極との間に配置される接着層及びセパレータを備え、前記接着層が、正極活物質層及び負極活物質層の少なくともいずれかの表面上に形成されている、上記［１］又は［２］に記載の蓄電素子。
［４］前記接着層が、正極活物質層及び負極活物質層の両方の表面上に形成されている、上記［３］に記載の蓄電素子。
［５］前記接着層が、熱可塑性樹脂及び絶縁性微粒子を含有する、上記［１］〜［４］のいずれかに記載の蓄電素子。
［６］前記接着層が、ポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体を含有する、上記［１］〜［５］のいずれかに記載の蓄電素子。
［７］前記プラスチックフィルムがポリオレフィンフィルムである、上記［１］〜［６］のいずれかに記載の蓄電素子。
［８］前記ラミネート外装体が矩形である、上記［１］〜［７］のいずれかに記載の蓄電素子。
［９］前記電極体が、正極と負極とがセパレータを介して交互に積層された積層電極体である、上記［１］〜［８］のいずれかに記載の蓄電素子。
The present inventors have conducted intensive studies and as a result, used an electrode body including a positive electrode, a negative electrode, and an adhesive layer disposed between the positive electrode and the negative electrode as an electrode body, and laminated the electrode body. The inventors have found that the above problem can be solved by setting the width of the welded portion at the periphery of the outer package to a certain range, and have completed the present invention described below. The gist of the present invention is the following [1] to [9].
[1] A power storage element in which an electrode body is accommodated in a laminate exterior body including a plastic film as an inner surface layer, wherein the electrode body is disposed between a positive electrode, a negative electrode, and the positive electrode and the negative electrode. An adhesive layer is provided, and a welded portion where plastic films are welded to each other is provided on the periphery of the laminate exterior body, and the width of the welded portion is 0% of the length in the longitudinal direction of the laminate exterior body. A power storage element having a ratio of 0.008 to 0.06.
[2] The power storage device according to [1], wherein the adhesive layer contains a binder, and the content of the binder is 30 to 80% by volume based on the total volume of the adhesive layer.
[3] The electrode body includes a positive electrode having a positive electrode active material layer, a negative electrode having a negative electrode active material layer, an adhesive layer and a separator disposed between the positive electrode and the negative electrode, wherein the adhesive layer has a positive electrode active material layer. The electricity storage device according to the above [1] or [2], which is formed on at least one of the surfaces of the material layer and the negative electrode active material layer.
[4] The power storage device according to [3], wherein the adhesive layer is formed on both surfaces of the positive electrode active material layer and the negative electrode active material layer.
[5] The power storage device according to any one of [1] to [4], wherein the adhesive layer contains a thermoplastic resin and insulating fine particles.
[6] The electricity storage device according to any one of [1] to [5], wherein the adhesive layer contains a polyvinylidene fluoride-hexafluoropropylene copolymer.
[7] The power storage device according to any one of [1] to [6], wherein the plastic film is a polyolefin film.
[8] The power storage device according to any one of [1] to [7], wherein the laminate exterior body is rectangular.
[9] The power storage device according to any one of [1] to [8], wherein the electrode body is a stacked electrode body in which a positive electrode and a negative electrode are alternately stacked with a separator interposed therebetween.
本発明によれば、ラミネート外装体の溶着部の幅を短くしつつ、外部応力が生じた場合に、溶着部が剥がれにくい蓄電素子を提供することができる。 Advantageous Effects of Invention According to the present invention, it is possible to provide a power storage element in which the welded portion is less likely to be peeled off when external stress occurs, while reducing the width of the welded portion of the laminate exterior body.
＜蓄電素子＞
本発明は、内面層としてプラスチックフィルムを備えるラミネート外装体に、電極体が収容されている蓄電素子である。該電極体は、正極と、負極と、前記正極と負極との間に配置される接着層とを備えている。また、ラミネート外装体の周縁には、プラスチックフィルム同士が溶着された溶着部が設けられており、溶着部の幅は、ラミネート外装体の長手方向の長さの０．００８〜０．０６倍である。
蓄電素子は、典型的には、リチウムイオン二次電池であるが、これに限らず、リチウムイオン二次電池以外の二次電池や、電気化学現象を伴うキャパシタ等であってもよい。
以下、本発明の蓄電素子について図１〜４を用いて詳細に説明するが、本発明はこれら図面に限定されるものではない。
<Storage element>
The present invention is a power storage element in which an electrode body is accommodated in a laminate exterior body having a plastic film as an inner surface layer. The electrode body includes a positive electrode, a negative electrode, and an adhesive layer disposed between the positive electrode and the negative electrode. Further, a welded portion where the plastic films are welded to each other is provided on the periphery of the laminate exterior body, and the width of the welded portion is 0.008 to 0.06 times the length in the longitudinal direction of the laminate exterior body. is there.
The power storage element is typically a lithium ion secondary battery, but is not limited thereto, and may be a secondary battery other than a lithium ion secondary battery, a capacitor involving an electrochemical phenomenon, or the like.
Hereinafter, the power storage device of the present invention will be described in detail with reference to FIGS. 1 to 4, but the present invention is not limited to these drawings.
（ラミネート外装体）
図１は、本発明の蓄電素子の概略構成を示す斜視図である。蓄電素子１０は、充放電反応が進行する電極体２０を、これを覆うラミネート外装体１１によって封止した構成を有する。電力を取り出すための正極集電板１２及び負極集電板１３が、ラミネート外装体１１の両側部から引き出されている。
ラミネート外装体１１は、扁平な袋状の構造を有しており、電極体２０を封止するために、周縁が溶着されている。ラミネート外装体の形状は、特に限定されず、楕円、円形、方形、矩形などいかなる形状でもよいが、一方向の長さがその垂直方向の長さに対して長い形状であることが好ましく、矩形であることがより好ましい。
ラミネート外装体１１は積層フィルム１４により構成されており、積層フィルム１４を重ねて、ヒートシール等で周縁を加熱し溶着することにより形成されている。具体的には、２枚の積層フィルム１４を重ね合わせ、すべての周縁を溶着させてラミネート外装体としてもよいし、１枚の積層フィルムを折り曲げて、折り曲げた部分以外の周縁を溶着させてラミネート外装体としてもよい。
(Laminated exterior body)
FIG. 1 is a perspective view illustrating a schematic configuration of a power storage device of the present invention. The energy storage device 10 has a configuration in which an electrode body 20 in which a charge / discharge reaction proceeds is sealed by a laminate exterior body 11 that covers the electrode body 20. A positive electrode current collector 12 and a negative electrode current collector 13 for extracting electric power are drawn out from both sides of the laminate exterior body 11.
The laminate exterior body 11 has a flat bag-like structure, and the periphery is welded to seal the electrode body 20. The shape of the laminate exterior body is not particularly limited, and may be any shape such as an ellipse, a circle, a square, and a rectangle, but it is preferable that the length in one direction is longer than the length in the vertical direction. Is more preferable.
The laminate exterior body 11 is formed of a laminated film 14, and is formed by stacking the laminated films 14 and heating and welding the periphery by heat sealing or the like. Specifically, two laminated films 14 may be overlapped, and all the edges may be welded to form a laminate exterior body. Alternatively, one laminated film may be folded, and the edges other than the folded portion may be welded and laminated. It may be an exterior body.
本発明では、溶着によって、実際にフィルム同士が溶着した溶着部の幅を、ラミネート外装体１１の長手方向の長さの０．００８〜０．０６倍としている。溶着部の幅がラミネート外装体１１の長手方向の長さの０．００８倍未満であると、蓄電素子１０に外部応力が加わった場合に溶着部分が剥離しやすくなる。一方、溶着部の幅がラミネート外装体１１の長手方向の長さの０．０６倍を超えると、ラミネート外装体１１の内部の空間が狭くなり、電極体２０のサイズを一定以下にする必要が生じ、電極体２０の形状選択の自由度が低下する。
本発明では、上記のようにラミネート外装体１１の溶着部の幅を比較的短くしても、溶着部が剥がれ難いため、ラミネート外装体の内部の空間を広くでき、電極体のサイズを大きくして容量を高めることが可能となる。
ラミネート外装体１１の溶着部の幅Ｄは、ラミネート外装体１１の長手方向の長さの０．０１倍〜０．０５倍であることが好ましく、０．０１５〜０．０４倍であることがより好ましく、０．０２〜０．０３倍であることが更に好ましい。
ここで、本発明における溶着部の幅Ｄとは、ラミネート外装体１１の実際に溶着されたすべての周縁上の溶着部について等間隔で４０点の溶着幅を測定し、その平均値とする。
ラミネート外装体の形状が矩形である場合の溶着部の幅Ｄは、ラミネート外装体の長手方向と短手方向とで同一であっても異なっていてもよいが、溶着部の幅を短くしつつ、外部応力による溶着部分の剥離を防止する観点から、ラミネート外装体の長手方向の溶着部の幅Ｄ１が、短手方向の溶着部の幅Ｄ２よりも長いことが好ましい。ラミネート外装体の長手方向の溶着部の幅に対する短手方向の溶着部の幅（Ｄ２／Ｄ１）は、０．２〜０．９倍がより好ましく、０．２５〜０．４５倍であることがより好ましい。
なお、ラミネート外装体の短手方向とは、ラミネート外装体の長手方向に直交する方向を意味する。
長手方向の溶着部の幅Ｄ１は、ラミネート外装体の長手方向の端部から、長手方向に向かって、実際に溶着されている部分の長さを、等間隔で２０点測定し、その平均値とする。
同様に、短手方向の溶着部の幅Ｄ２は、ラミネート外装体の短手方向の端部から、短手方向に向かって、実際に溶着されている部分の長さを、等間隔で２０点測定し、その平均値とする。
In the present invention, the width of the welded portion where the films are actually welded to each other by welding is set to be 0.008 to 0.06 times the length of the laminate exterior body 11 in the longitudinal direction. When the width of the welded portion is less than 0.008 times the length of the laminate exterior body 11 in the longitudinal direction, the welded portion is easily peeled off when an external stress is applied to the power storage element 10. On the other hand, if the width of the welded portion exceeds 0.06 times the length in the longitudinal direction of the laminate exterior body 11, the space inside the laminate exterior body 11 becomes narrow, and it is necessary to keep the size of the electrode body 20 below a certain value. As a result, the degree of freedom in selecting the shape of the electrode body 20 decreases.
In the present invention, even if the width of the welded portion of the laminate exterior body 11 is relatively short as described above, the welded portion is difficult to peel off, so that the internal space of the laminate exterior body can be widened and the size of the electrode body can be increased. Capacity can be increased.
The width D of the welded portion of the laminate exterior body 11 is preferably 0.01 to 0.05 times the longitudinal length of the laminate exterior body 11, and is preferably 0.015 to 0.04 times. More preferably, it is still more preferably 0.02 to 0.03 times.
Here, the width D of the welded portion in the present invention is defined as an average value of 40 welded widths measured at equal intervals with respect to the welded portions on all the peripheral edges of the laminate exterior body 11 actually welded.
The width D of the welded portion when the shape of the laminate exterior body is rectangular may be the same or different in the longitudinal direction and the shorter direction of the laminate exterior body, while reducing the width of the welded portion. From the viewpoint of preventing peeling of the welded portion due to external stress, it is preferable that the width D1 of the welded portion in the longitudinal direction of the laminate exterior body is longer than the width D2 of the welded portion in the lateral direction. The width (D2 / D1) of the welded portion in the short direction with respect to the width of the welded portion in the longitudinal direction of the laminate exterior body is more preferably 0.2 to 0.9 times, and preferably 0.25 to 0.45 times. Is more preferred.
In addition, the short direction of the laminate exterior body means a direction orthogonal to the longitudinal direction of the laminate exterior body.
The width D1 of the welded portion in the longitudinal direction is obtained by measuring the length of the portion actually welded from the longitudinal end of the laminate exterior body in the longitudinal direction at equal intervals at 20 points, and the average value thereof And
Similarly, the width D2 of the welded portion in the transverse direction is obtained by dividing the length of the portion actually welded from the end in the transverse direction of the laminate exterior body in the transverse direction by 20 points at equal intervals. Measure and take the average value.
上記したラミネート外装体１１を形成するための積層フィルム１４は、内面層としてプラスチックフィルムを備えるものであり、２層構造であっても３層以上の構造であてもよい。積層フィルム１４は、例えば図２に示すように、プラスチックフィルム１５、金属層１６、及びプラスチックフィルム１７がこの順で積層された積層フィルムであることが好ましい。
プラスチックフィルム１５は外面層を構成する熱可塑性樹脂層であり、外力による傷防止の観点から、ポリエチレンテレフタレート、ナイロン等のフィルムが好ましい。プラスチックフィルム１７は、内面層を構成する層であり、熱を加えて溶着させるための熱可塑性樹脂層であるため、高密度ポリエチレン、低密度ポリエチレン、直鎖状低密度ポリエチレン、ポリプロピレンなどのポリオレフィンフィルムが好ましく、中でもポリプロピレンフィルムがより好ましい。
金属層１６は、例えば、アルミニウム、ステンレス、銅、ニッケルなどを挙げることができ、中でもアルミニウムが好ましい。
積層フィルムは、その内面層同士を溶着させることによりラミネート外装体を形成することができる。
The laminated film 14 for forming the above-mentioned laminated exterior body 11 includes a plastic film as an inner surface layer, and may have a two-layer structure or a structure of three or more layers. As shown in FIG. 2, for example, the laminated film 14 is preferably a laminated film in which a plastic film 15, a metal layer 16, and a plastic film 17 are laminated in this order.
The plastic film 15 is a thermoplastic resin layer constituting an outer surface layer, and is preferably a film of polyethylene terephthalate, nylon, or the like from the viewpoint of preventing damage due to external force. The plastic film 17 is a layer constituting the inner surface layer, and is a thermoplastic resin layer for welding by applying heat. Therefore, a polyolefin film such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, or polypropylene is used. Are preferable, and a polypropylene film is more preferable.
The metal layer 16 includes, for example, aluminum, stainless steel, copper, nickel and the like, and among them, aluminum is preferable.
The laminated film can form a laminate exterior body by welding the inner surface layers thereof.
（電極体）
本発明の蓄電素子は、ラミネート外装体に電極体が収容されている。電極体は、正極と、負極と、該正極と負極との間に配置される接着層とを備えている。
電極体が接着層を備えることで、電極体が強固になり、外部応力に起因した面方向及び厚み方向の変形が防止される。外部応力に対する電極体の変形が防止されると、ラミネート外装体の撓み及び歪みも抑制される。その結果、ラミネート外装体の溶着幅を短くしても、溶着部が剥離し難くなり、具体的には上記したように、溶着部の幅を、比較的短くすることが可能となる。
図３は、第１の実施形態の蓄電素子の断面図（図１のＡ−Ａ線）を示している。第１の実施形態の蓄電素子は、図３に示すとおり、ラミネート外装体１１に、電極体２０が封入されている。電極体２０は、正極活物質層２１を有する正極２３と、負極活物質層２６を有する負極２８と、正極２３と負極２８との間に配置される接着層２４及びセパレータ２５を備えている。
本発明において電極体は、セパレータを備えることは必須ではないものの、セパレータを備えていることが好ましい。セパレータを備えることにより、正極及び負極の間の短絡が効果的に防止される。電極体がセパレータを備えない場合は、正極と負極との間に配置される接着層が、セパレータとしての機能も兼ね備えるようにすればよい。
正極２３は、詳細には、正極集電体２２と、正極集電体２２の表面に積層された正極活物質層２１とを備えている。負極２８も同様に、負極集電体２７と、負極集電体２７の表面に積層された負極活物質層２６とを備えている。正極集電体２２は、正極集電板１２と電気的に接続されており、負極集電体２７は、負極集電板１３と電気的に接続されている。
２つの接着層２４は、それぞれ正極２３の正極活物質層２１及び負極２８の負極活物質層２６の表面上に形成されている。これにより、セパレータ２５と正極２３、セパレータ２５と負極２８とがそれぞれ接着層２４により固定され、電極体２０全体が強固になり、ラミネート外装体１１の溶着部の幅を短くても、外部応力による変形が防止され、溶着部の剥がれが抑制される。
図３では、接着層２４を、セパレータ２５に対向している正極活物質層２１及び負極活物質層２６の両方の表面に形成させているが、いずれか一方の表面にのみ形成させてもよい。ただし、接着層２４が正極活物質層２１及び負極活物質層２６の両方の表面に形成されていることで、電極体２０がより強固になり、ラミネート外装体１１の溶着幅をより短くすることが可能となる。
(Electrode body)
In the power storage device of the present invention, an electrode body is accommodated in a laminate outer package. The electrode body includes a positive electrode, a negative electrode, and an adhesive layer disposed between the positive electrode and the negative electrode.
By providing the electrode body with the adhesive layer, the electrode body is strengthened, and deformation in the plane direction and the thickness direction due to external stress is prevented. When deformation of the electrode body due to external stress is prevented, bending and distortion of the laminate exterior body are also suppressed. As a result, even if the welding width of the laminate exterior body is reduced, the welded portion is less likely to be peeled off. Specifically, as described above, the width of the welded portion can be relatively reduced.
FIG. 3 is a cross-sectional view (AA line in FIG. 1) of the power storage device according to the first embodiment. In the power storage device of the first embodiment, as shown in FIG. 3, an electrode body 20 is sealed in a laminate exterior body 11. The electrode body 20 includes a positive electrode 23 having a positive electrode active material layer 21, a negative electrode 28 having a negative electrode active material layer 26, an adhesive layer 24 disposed between the positive electrode 23 and the negative electrode 28, and a separator 25.
In the present invention, the electrode body is not necessarily provided with the separator, but is preferably provided with the separator. By providing the separator, a short circuit between the positive electrode and the negative electrode is effectively prevented. When the electrode body does not include a separator, the adhesive layer disposed between the positive electrode and the negative electrode may have a function as a separator.
Specifically, the positive electrode 23 includes a positive electrode current collector 22 and a positive electrode active material layer 21 stacked on the surface of the positive electrode current collector 22. Similarly, the negative electrode 28 includes a negative electrode current collector 27 and a negative electrode active material layer 26 laminated on the surface of the negative electrode current collector 27. The positive electrode current collector 22 is electrically connected to the positive electrode current collector 12, and the negative electrode current collector 27 is electrically connected to the negative electrode current collector 13.
The two adhesive layers 24 are formed on the surfaces of the positive electrode active material layer 21 of the positive electrode 23 and the negative electrode active material layer 26 of the negative electrode 28, respectively. As a result, the separator 25 and the positive electrode 23, and the separator 25 and the negative electrode 28 are fixed by the adhesive layer 24, and the entire electrode body 20 becomes strong. Deformation is prevented, and peeling of the welded portion is suppressed.
In FIG. 3, the adhesive layer 24 is formed on both surfaces of the positive electrode active material layer 21 and the negative electrode active material layer 26 facing the separator 25, but may be formed on only one of the surfaces. . However, since the adhesive layer 24 is formed on both surfaces of the positive electrode active material layer 21 and the negative electrode active material layer 26, the electrode body 20 becomes stronger, and the welding width of the laminate exterior body 11 is made shorter. Becomes possible.
図４は、第２の実施形態の蓄電素子の断面図（図１のＡ−Ａ線）を示している。第２の実施形態の蓄電素子は、図４に示すとおり、ラミネート外装体１１に、電極体２０’が封入されている。電極体２０’は、正極２３、負極２８、接着層２４、及びセパレータ２５とで構成されている。電極体２０’は、正極２３と負極２８とが、接着層２４及びセパレータ２５を介して交互に積層された積層電極体である。
電極体２０’は、正極２３と負極２８との間に接着層２４を有しており、正極２３とセパレータ２５、負極２８とセパレータ２５それぞれが、接着層２４により固定されている。
接着層２４は、第１の実施形態と同様に、正極２３の正極活物質層２１及び負極２８の負極活物質層２６の表面上に形成されている。これにより、セパレータ２５と正極２３、セパレータ２５と負極２８とがそれぞれ接着層２４により固定され、電極体２０’全体が強固になり、ラミネート外装体１１の溶着部の幅を短くても、外部応力による変形が防止され、溶着部の剥がれが抑制される。
図４では、接着層２４を、セパレータ２５に対向している正極活物質層２１及び負極活物質層２６の両方の表面に形成させているが、いずれか一方の表面にのみ形成させてもよい。ただし、接着層２４が正極活物質層２１及び負極活物質層２６の両方の表面に形成されていることで、電極体２０’全体がより強固になり、ラミネート外装体１１の溶着幅をより短くすることが可能となる。
本発明において、電極体が、積層電極体である場合において、複数ある正極活物質層とセパレータとの間、及び複数ある負極活物質層とセパレータとの間のすべてに接着層が存在することが特に好ましい。
セパレータ２５は、図４のように一枚の長いシートを複数個所で折り曲げられて形成されている。すなわち、セパレータ２５は、各正極２３及び各負極２８との間に存在する複数の平面部２５Ａと、該複数の平面部２５Ａを連結する屈曲部２５Ｂとから構成されている。
このような第２の実施形態である蓄電素子も、ラミネート外装体の溶着部の幅を短くしつつ、外部応力により溶着部の剥がれを抑制することができる。
FIG. 4 is a cross-sectional view (a line AA in FIG. 1) of the power storage element according to the second embodiment. As shown in FIG. 4, the power storage element of the second embodiment has an electrode body 20 ′ sealed in a laminate exterior body 11. The electrode body 20 ′ includes a positive electrode 23, a negative electrode 28, an adhesive layer 24, and a separator 25. The electrode body 20 'is a laminated electrode body in which a positive electrode 23 and a negative electrode 28 are alternately laminated via an adhesive layer 24 and a separator 25.
The electrode body 20 'has an adhesive layer 24 between the positive electrode 23 and the negative electrode 28, and the positive electrode 23 and the separator 25, and the negative electrode 28 and the separator 25 are fixed by the adhesive layer 24, respectively.
The adhesive layer 24 is formed on the surfaces of the positive electrode active material layer 21 of the positive electrode 23 and the negative electrode active material layer 26 of the negative electrode 28, as in the first embodiment. As a result, the separator 25 and the positive electrode 23 and the separator 25 and the negative electrode 28 are fixed by the adhesive layer 24, and the entire electrode body 20 'becomes strong. Deformation is prevented, and peeling of the welded portion is suppressed.
In FIG. 4, the adhesive layer 24 is formed on both surfaces of the positive electrode active material layer 21 and the negative electrode active material layer 26 facing the separator 25, but may be formed on only one of the surfaces. . However, since the adhesive layer 24 is formed on both surfaces of the positive electrode active material layer 21 and the negative electrode active material layer 26, the entire electrode body 20 'becomes stronger, and the welding width of the laminate exterior body 11 is reduced. It is possible to do.
In the present invention, when the electrode body is a stacked electrode body, the adhesive layer may be present between the plurality of positive electrode active material layers and the separator, and between the plurality of negative electrode active material layers and the separator. Particularly preferred.
The separator 25 is formed by bending a single long sheet at a plurality of positions as shown in FIG. That is, the separator 25 includes a plurality of flat portions 25A existing between the respective positive electrodes 23 and the respective negative electrodes 28, and a bent portion 25B connecting the plurality of flat portions 25A.
The power storage element according to the second embodiment can also suppress peeling of the welded portion due to external stress while shortening the width of the welded portion of the laminate exterior body.
（接着層の組成）
本発明の電極体における接着層は、上記例示した各実施形態のように、正極と負極との間に配置され、電極体を構成する正極、負極、及び必要に応じて使用するセパレータなどの各部材同士を固定できるものであれば特に制限されないが、バインダーを含むことが好ましい。バインダーを含むことで、電極体が強固になり、外部応力に対する変形を防止しやすくなる。また、バインダーを含有させることにより、必要に応じて接着層に含有される絶縁性微粒子を結着することができる。バインダーとしては、特に制限されないが、熱可塑性樹脂が好ましい。
バインダーの具体例としては、例えば、ポリフッ化ビニリデン（ＰＶＤＦ）、ポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（ＰＶＤＦ−ＨＦＰ）、ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素含有樹脂、ポリメチルアクリレート（ＰＭＡ）、ポリメチルメタクリレート（ＰＭＭＡ）などのアクリル樹脂、ポリ酢酸ビニル、ポリイミド（ＰＩ）、ポリアミド（ＰＡ）、ポリ塩化ビニル（ＰＶＣ）、ポリエーテルニトリル（ＰＥＮ）、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、ポリアクリロニトリル（ＰＡＮ）、アクリロニトリル・ブタジエンゴム、スチレンブタジエンゴム、ポリ（メタ）アクリル酸、カルボキシメチルセルロース、ヒドロキシエチルセルロース、及びポリビニルアルコール等が挙げられる。これらバインダーは、１種単独で使用されてもよいし、２種以上が併用されてもよい。また、カルボキシメチルセルロースなどは、ナトリウム塩などの塩の態様にて使用されていてもよい。これらの中でも、電極体の外部応力に対する変形を防止しやすくする観点からフッ素含有樹脂であることが好ましく、フッ素含有樹脂の中でもポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（ＰＶＤＦ−ＨＦＰ）を使用することが好ましい。
接着層中のバインダーの含有量は、接着層全体積に対して、５〜８０体積％であることが好ましく、１０〜５０体積％であることがより好ましい。このような範囲であると、電極体が強固になり、外部応力に対する変形を防止しやすくなる。
(Composition of adhesive layer)
The adhesive layer in the electrode body of the present invention is disposed between the positive electrode and the negative electrode as in each of the above-described embodiments, and includes a positive electrode, a negative electrode, and a separator used as necessary, which constitute the electrode body. There is no particular limitation as long as the members can be fixed, but it is preferable to include a binder. By including the binder, the electrode body becomes strong, and it becomes easy to prevent deformation due to external stress. In addition, by containing a binder, insulating fine particles contained in the adhesive layer can be bound as necessary. The binder is not particularly limited, but is preferably a thermoplastic resin.
Specific examples of the binder include, for example, fluorine-containing resins such as polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polytetrafluoroethylene (PTFE), and polymethyl acrylate (PMA). ), Acrylic resin such as polymethyl methacrylate (PMMA), polyvinyl acetate, polyimide (PI), polyamide (PA), polyvinyl chloride (PVC), polyether nitrile (PEN), polyethylene (PE), polypropylene (PP) , Polyacrylonitrile (PAN), acrylonitrile-butadiene rubber, styrene-butadiene rubber, poly (meth) acrylic acid, carboxymethylcellulose, hydroxyethylcellulose, and polyvinyl alcohol. These binders may be used alone or in combination of two or more. Further, carboxymethyl cellulose and the like may be used in the form of a salt such as a sodium salt. Among these, a fluorine-containing resin is preferable from the viewpoint of easily preventing the electrode body from being deformed by external stress, and among the fluorine-containing resins, polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP) is used. Is preferred.
The content of the binder in the adhesive layer is preferably from 5 to 80% by volume, more preferably from 10 to 50% by volume, based on the total volume of the adhesive layer. In such a range, the electrode body becomes strong, and it becomes easy to prevent deformation due to external stress.
接着層は、上記バインダーと共に絶縁性微粒子を含有することが好ましい。接着層が絶縁性微粒子を含有することで、正極及び負極の間の短絡が効果的に防止される。
絶縁性微粒子は、絶縁性であれば特に限定されず、有機粒子、無機粒子の何れであってもよい。具体的な有機粒子としては、例えば、架橋ポリメタクリル酸メチル、架橋スチレン−アクリル酸共重合体、架橋アクリロニトリル樹脂、ポリアミド樹脂、ポリイミド樹脂、ポリ（２−アクリルアミド−２−メチルプロパンスルホン酸リチウム）、ポリアセタール樹脂、エポキシ樹脂、ポリエステル樹脂、フェノール樹脂、メラミン樹脂等の有機化合物から構成される粒子が挙げられる。無機粒子としては二酸化ケイ素、窒化ケイ素、アルミナ、ベーマイト、チタニア、ジルコニア、窒化ホウ素、酸化亜鉛、二酸化スズ、酸化ニオブ（Ｎｂ２Ｏ５）、酸化タンタル（Ｔａ２Ｏ５）、フッ化カリウム、フッ化リチウム、クレイ、ゼオライト、炭酸カルシウム等の無機化合物から構成される粒子が挙げられる。また、無機粒子は、ニオブ−タンタル複合酸化物、マグネシウム−タンタル複合酸化物等の公知の複合酸化物から構成される粒子であってもよい。絶縁性微粒子は１種を単独で用いてもよいし、複数種を併用してもよい。
絶縁性微粒子の平均粒子径は、接着層の厚さよりも小さければ特に限定されず、例えば０．００１〜１μｍ、好ましくは０．０５〜０．８μｍ、より好ましくは０．１〜０．６μｍである。
なお、平均粒子径は、レーザー回折・散乱法によって求めた絶縁性微粒子の粒度分布において、体積積算が５０％での粒径（Ｄ５０）を意味する。
また、絶縁性微粒子は、平均粒子径が上記範囲内の１種が単独で使用されてもよいし、平均粒子径の異なる２種の絶縁性微粒子が混合されて使用されてもよい。
接着層に含有される絶縁性微粒子の含有量は、接着層の全体積に対して、好ましくは２０〜９５体積％、より好ましくは５０〜９０体積％である。絶縁性微粒子の含有量が上記範囲内であると、適切な絶縁性が付与される。
The adhesive layer preferably contains insulating fine particles together with the binder. When the adhesive layer contains the insulating fine particles, a short circuit between the positive electrode and the negative electrode is effectively prevented.
The insulating fine particles are not particularly limited as long as they are insulating, and may be organic particles or inorganic particles. Specific organic particles include, for example, cross-linked polymethyl methacrylate, cross-linked styrene-acrylic acid copolymer, cross-linked acrylonitrile resin, polyamide resin, polyimide resin, poly (lithium 2-acrylamido-2-methylpropanesulfonate), Examples include particles composed of an organic compound such as a polyacetal resin, an epoxy resin, a polyester resin, a phenol resin, and a melamine resin. Examples of the inorganic particles include silicon dioxide, silicon nitride, alumina, boehmite, titania, zirconia, boron nitride, zinc oxide, tin dioxide, niobium oxide (Nb 2 O 5 ), tantalum oxide (Ta 2 O 5 ), potassium fluoride, and fluoride. Examples include particles composed of inorganic compounds such as lithium chloride, clay, zeolite, and calcium carbonate. The inorganic particles may be particles composed of a known composite oxide such as a niobium-tantalum composite oxide or a magnesium-tantalum composite oxide. One kind of the insulating fine particles may be used alone, or a plurality of kinds may be used in combination.
The average particle diameter of the insulating fine particles is not particularly limited as long as it is smaller than the thickness of the adhesive layer, and is, for example, 0.001 to 1 μm, preferably 0.05 to 0.8 μm, more preferably 0.1 to 0.6 μm. is there.
The average particle size means the particle size (D50) at a volume integration of 50% in the particle size distribution of the insulating fine particles obtained by the laser diffraction / scattering method.
As the insulating fine particles, one kind having an average particle diameter within the above range may be used alone, or two kinds of insulating fine particles having different average particle diameters may be used as a mixture.
The content of the insulating fine particles contained in the adhesive layer is preferably from 20 to 95% by volume, more preferably from 50 to 90% by volume, based on the total volume of the adhesive layer. When the content of the insulating fine particles is within the above range, appropriate insulating properties are provided.
接着層の厚さは、特に限定されないが、１〜２５μｍが好ましい。接着層の厚さを２５μｍ以下とすることで、充電性等の蓄電素子としての性能が良好となる。また、１μｍ以上とすることで、電極体の外部応力に対する変形が防止され易くなり、ラミネート外装体の溶着部の幅をより短くすることができる。接着層の厚さは、３〜２０μｍがより好ましく、４〜１５μｍがさらに好ましい。 The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 25 μm. By setting the thickness of the adhesive layer to 25 μm or less, the performance as a power storage element such as chargeability is improved. When the thickness is 1 μm or more, deformation of the electrode body due to external stress is easily prevented, and the width of the welded portion of the laminate exterior body can be further reduced. The thickness of the adhesive layer is more preferably 3 to 20 μm, and further preferably 4 to 15 μm.
接着層は、バインダー、絶縁性微粒子、溶剤などを含有する接着層用組成物を、正極活物質層、負極活物質層、セパレータなどの部材上に塗布し、乾燥させることで形成させることができる。そして、ある特定の部材上に形成させた接着層上に別の部材を積層して、熱プレス等を行うことにより、部材同士を接合することができる。 The adhesive layer can be formed by applying a composition for an adhesive layer containing a binder, insulating fine particles, a solvent, and the like onto a member such as a positive electrode active material layer, a negative electrode active material layer, and a separator and drying the resultant. . Then, by laminating another member on the adhesive layer formed on a specific member and performing hot pressing or the like, the members can be joined to each other.
（正極）
本発明の電極体における正極は、好ましくは、正極集電体と、正極集電体の片面又は両面に積層された正極活物質層とを有する。正極活物質層は、典型的には、正極活物質と、正極用バインダーとを含む。
正極活物質としては、金属酸リチウム化合物が挙げられる。金属酸リチウム化合物としては、コバルト酸リチウム（ＬｉＣｏＯ２）、ニッケル酸リチウム（ＬｉＮｉＯ２）、マンガン酸リチウム（ＬｉＭｎ２Ｏ４）等が例示できる。また、オリビン型リン酸鉄リチウム（ＬｉＦｅＰＯ４）などであってもよい。さらに、リチウム以外の金属を複数使用したものでもよく、リチウムニッケルコバルトアルミニウム系酸化物（ＮＣＡ）などを使用してもよい。
正極活物質の含有量は、正極活物質層の全体積に対して、８０〜９９．９体積％が好ましく、９０〜９９体積％がより好ましい。
(Positive electrode)
The positive electrode in the electrode body of the present invention preferably has a positive electrode current collector and a positive electrode active material layer laminated on one or both surfaces of the positive electrode current collector. The positive electrode active material layer typically includes a positive electrode active material and a positive electrode binder.
Examples of the positive electrode active material include a lithium metal oxide compound. Examples of the lithium metal oxide compound include lithium cobaltate (LiCoO 2 ), lithium nickelate (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), and the like. Further, olivine-type lithium iron phosphate (LiFePO 4 ) may be used. Further, a plurality of metals other than lithium may be used, and a lithium nickel cobalt aluminum oxide (NCA) or the like may be used.
The content of the positive electrode active material is preferably from 80 to 99.9% by volume, more preferably from 90 to 99% by volume, based on the total volume of the positive electrode active material layer.
正極用バインダーとしては、特に制限されないが、具体例としては、ポリフッ化ビニリデン（ＰＶＤＦ）、ポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（ＰＶＤＦ−ＨＦＰ）、ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素含有樹脂、ポリメチルアクリレート（ＰＭＡ）、ポリメチルメタクリレート（ＰＭＭＡ）などのアクリル樹脂、ポリ酢酸ビニル、ポリイミド（ＰＩ）、ポリアミド（ＰＡ）、ポリ塩化ビニル（ＰＶＣ）、ポリエーテルニトリル（ＰＥＮ）、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、ポリアクリロニトリル（ＰＡＮ）、アクリロニトリル・ブタジエンゴム、スチレンブタジエンゴム、ポリ（メタ）アクリル酸、カルボキシメチルセルロース、ヒドロキシエチルセルロース、及びポリビニルアルコール等が挙げられる。これらバインダーは、１種単独で使用されてもよいし、２種以上が併用されてもよい。また、カルボキシメチルセルロースなどは、ナトリウム塩などの塩の態様にて使用されていてもよい。 The binder for the positive electrode is not particularly limited, but specific examples thereof include fluorine-containing materials such as polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), and polytetrafluoroethylene (PTFE). Resins, acrylic resins such as polymethyl acrylate (PMA) and polymethyl methacrylate (PMMA), polyvinyl acetate, polyimide (PI), polyamide (PA), polyvinyl chloride (PVC), polyether nitrile (PEN), polyethylene ( PE), polypropylene (PP), polyacrylonitrile (PAN), acrylonitrile-butadiene rubber, styrene-butadiene rubber, poly (meth) acrylic acid, carboxymethyl cellulose, hydroxyethyl cellulose, and polyvinyl alcohol Call, and the like. These binders may be used alone or in combination of two or more. Further, carboxymethyl cellulose and the like may be used in the form of a salt such as a sodium salt.
正極活物質層における正極用バインダーの含有量は、正極活物質層の全体積に対して、０．１〜２０体積％であることが好ましく、１〜１０体積％がより好ましい。
正極活物質層の厚みは、特に限定されないが、１０〜２００μｍであることが好ましく、５０〜１５０μｍであることがより好ましい。
また、正極集電体となる材料は、例えば、アルミニウム、銅、チタン、ニッケル、ステンレス鋼等の導電性を有する金属が挙げられ、好ましくはアルミニウム又は銅、より好ましくはアルミニウムが使用される。正極集電体は、一般的に金属箔からなり、その厚さは、特に限定されないが、１〜５０μｍが好ましい。
The content of the positive electrode binder in the positive electrode active material layer is preferably 0.1 to 20% by volume, more preferably 1 to 10% by volume, based on the total volume of the positive electrode active material layer.
The thickness of the positive electrode active material layer is not particularly limited, but is preferably from 10 to 200 μm, and more preferably from 50 to 150 μm.
Examples of the material for the positive electrode current collector include metals having conductivity, such as aluminum, copper, titanium, nickel, and stainless steel. Preferably, aluminum or copper, and more preferably, aluminum is used. The positive electrode current collector is generally made of a metal foil, and its thickness is not particularly limited, but is preferably 1 to 50 μm.
（負極）
本発明の電極体における負極は、好ましくは、負極集電体と、負極集電体の片面又は両面に積層された負極活物質層とを有する。負極活物質層は、典型的には、負極活物質と、負極用バインダーとを含む。
負極活物質層に使用される負極活物質としては、グラファイト、ハードカーボンなどの炭素材料、スズ化合物とシリコンと炭素の複合体、リチウムなどが挙げられるが、これら中では炭素材料が好ましく、グラファイトがより好ましい。
負極活物質は、特に限定されないが、その平均粒子径が０．５〜５０μｍであることが好ましく、１〜３０μｍであることがより好ましい。
負極活物質層における負極活物質の含有量は、負極活物質層全体に対して、８０〜９９．９体積％であることが好ましく、９０〜９９体積％がより好ましい。
(Negative electrode)
The negative electrode in the electrode body of the present invention preferably has a negative electrode current collector and a negative electrode active material layer laminated on one or both surfaces of the negative electrode current collector. The negative electrode active material layer typically includes a negative electrode active material and a negative electrode binder.
Examples of the negative electrode active material used for the negative electrode active material layer include carbon materials such as graphite and hard carbon, a composite of a tin compound and silicon and carbon, and lithium. Among these, carbon materials are preferable, and graphite is preferable. More preferred.
The negative electrode active material is not particularly limited, but preferably has an average particle size of 0.5 to 50 µm, more preferably 1 to 30 µm.
The content of the negative electrode active material in the negative electrode active material layer is preferably 80 to 99.9% by volume, more preferably 90 to 99% by volume, based on the whole negative electrode active material layer.
負極活物質層に含有される負極用バインダーとしては、上記した正極材料にて使用されるバインダーと同種のものが使用できる。
負極活物質層における負極用バインダーの含有量は、負極活物質層の全体積に対して、０．１〜２０体積％であることが好ましく、１〜１０体積％がより好ましい。
負極活物質層は、導電助剤を含有してもよい。導電助剤は、上記負極活物質よりも導電性が高い材料が使用され、具体的には、ケッチェンブラック、アセチレンブラック、カーボンナノチューブ、棒状カーボンなどの炭素材料などが挙げられる。
負極活物質層の厚みは、特に限定されないが、１０〜２００μｍであることが好ましく、５０〜１５０μｍであることがより好ましい。
As the negative electrode binder contained in the negative electrode active material layer, the same kind of binder as used in the above-described positive electrode material can be used.
The content of the negative electrode binder in the negative electrode active material layer is preferably 0.1 to 20% by volume, more preferably 1 to 10% by volume, based on the total volume of the negative electrode active material layer.
The negative electrode active material layer may contain a conductive auxiliary. As the conductive additive, a material having higher conductivity than the above-described negative electrode active material is used, and specific examples thereof include carbon materials such as Ketjen black, acetylene black, carbon nanotube, and rod-like carbon.
The thickness of the negative electrode active material layer is not particularly limited, but is preferably from 10 to 200 μm, and more preferably from 50 to 150 μm.
負極集電体を構成する材料としては、例えば、銅、アルミニウム、チタン、ニッケル、ステンレス鋼等の導電性を有する金属が挙げられ、これらの中ではアルミニウム又は銅が好ましく、銅がより好ましい。負極集電体は、一般的に金属箔からなり、その厚さは、特に限定されないが、１〜５０μｍが好ましい。 Examples of the material constituting the negative electrode current collector include conductive metals such as copper, aluminum, titanium, nickel, and stainless steel. Among these, aluminum or copper is preferable, and copper is more preferable. The negative electrode current collector is generally made of a metal foil, and its thickness is not particularly limited, but is preferably 1 to 50 μm.
（セパレータ）
セパレータとしては、多孔性の高分子膜、不織布、ガラスファイバー等が挙げられ、これらの中では多孔性の高分子膜が好ましい。多孔性の高分子膜としては、エチレン系多孔質フィルムなどのオレフィン系多孔質フィルムが例示される。セパレータの厚さは、特に限定されないが、５〜２５μｍが好ましい。
また、セパレータは、後述する電解質を保持してもよい。
(Separator)
Examples of the separator include a porous polymer film, a nonwoven fabric, and a glass fiber. Among these, a porous polymer film is preferable. Examples of the porous polymer film include an olefin-based porous film such as an ethylene-based porous film. The thickness of the separator is not particularly limited, but is preferably 5 to 25 μm.
Further, the separator may hold an electrolyte described later.
（電解質）
本発明の蓄電素子は、電解質を備える。電解質は特に限定されず、蓄電素子で使用される公知の電解質を使用すればよい。電解質としては例えば電解液を使用する。
電解液としては、有機溶媒と、電解質塩を含む電解液が例示できる。有機溶媒としては、例えば、エチレンカーボネート、プロピレンカーボネート、ジメチルカーボネート、γ−ブチロラクトン、スルホラン、ジメチルスルホキシド、アセトニトリル、ジメチルホルムアミド、ジメチルアセトアミド、１，２−ジメトキシエタン、１，２−ジエトキシエタン、テトロヒドラフラン、２−メチルテトラヒドロフラン、ジオキソラン、メチルアセテートなどの極性溶媒、又はこれら溶媒の２種類以上の混合物が挙げられる。電解質塩としては、ＬｉＣｌＯ４、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＡｓＦ６、ＬｉＣＦ６、ＬｉＣＦ３ＣＯ２、ＬｉＰＦ６ＳＯ３、ＬｉＮ（ＳＯ３ＣＦ３）２、Ｌｉ（ＳＯ２ＣＦ２ＣＦ３）２、ＬｉＮ（ＣＯＣＦ３）２及びＬｉＮ（ＣＯＣＦ２ＣＦ３）２、リチウムビスオキサレートボラート（ＬｉＢ（Ｃ２Ｏ４）２等のリチウムを含む塩が挙げられる。また、有機酸リチウム塩−三フッ化ホウ素錯体、ＬｉＢＨ４等の錯体水素化物等の錯体が挙げられる。これらの塩又は錯体は、１種単独で使用してもよいが、２種以上の混合物であってもよい。
また、電解質は、上記電解液に更に高分子化合物を含むゲル状電解質であってもよい。高分子化合物としては、例えば、ポリフッ化ビニリデン等のフッ素系ポリマー、ポリ（メタ）アクリル酸メチル等のポリアクリル系ポリマーが挙げられる。なお、ゲル状電解質は、セパレータとして使用されてもよい。
電解質は、負極及び正極間に配置されればよく、例えば、電解液は、上記した負極、正極、及びセパレータが内部に収納されたラミネート外装体に充填される。また、電解質は、例えば、負極又は正極上に塗布されて負極及び正極間に配置されてもよい。
(Electrolytes)
The storage element of the present invention includes an electrolyte. The electrolyte is not particularly limited, and a known electrolyte used for a power storage element may be used. For example, an electrolyte is used as the electrolyte.
Examples of the electrolyte include an electrolyte containing an organic solvent and an electrolyte salt. Examples of the organic solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, γ-butyrolactone, sulfolane, dimethyl sulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, 1,2-dimethoxyethane, 1,2-diethoxyethane, and tetrohydra. Examples thereof include polar solvents such as furan, 2-methyltetrahydrofuran, dioxolan, and methyl acetate, and a mixture of two or more of these solvents. Examples of electrolyte salts include LiClO 4 , LiPF 6 , LiBF 4 , LiAsF 6 , LiCF 6 , LiCF 3 CO 2 , LiPF 6 SO 3 , LiN (SO 3 CF 3 ) 2 , Li (SO 2 CF 2 CF 3 ) 2 , LiN (COCF 3 ) 2 , a salt containing lithium such as LiN (COCF 2 CF 3 ) 2 , lithium bisoxalate borate (LiB (C 2 O 4 ) 2, and the like; Examples include complexes such as boron hydride complexes and complex hydrides such as LiBH 4. These salts or complexes may be used alone or in a mixture of two or more.
Further, the electrolyte may be a gel electrolyte further containing a polymer compound in the above-mentioned electrolytic solution. Examples of the polymer compound include a fluorine-based polymer such as polyvinylidene fluoride and a polyacryl-based polymer such as poly (methyl meth) acrylate. Note that the gel electrolyte may be used as a separator.
The electrolyte may be disposed between the negative electrode and the positive electrode. For example, the electrolytic solution is filled in a laminate exterior body in which the above-described negative electrode, positive electrode, and separator are housed. Further, the electrolyte may be, for example, applied on the negative electrode or the positive electrode and disposed between the negative electrode and the positive electrode.
（蓄電素子の製造方法）
本発明の蓄電素子は、例えば、電極体を、ラミネート外装体を形成する積層フィルムにより挟み込んで、フィルム周縁を溶着させることで製造できる。この際、積層フィルムを２枚用いて、上下から電極体を挟み込んで周縁を溶着させてもよいし、１枚の積層フィルムを折り曲げて、間に電極体を挟みこんで周縁を溶着させてもよい。
溶着する方法は特に制限されず、インパルス方式、熱板方式、高周波誘導加熱方式、超音波誘導加熱方式等を用いることができる。
(Method of manufacturing power storage element)
The electric storage element of the present invention can be manufactured, for example, by sandwiching an electrode body between laminated films forming a laminate exterior body and welding the film periphery. At this time, the periphery may be welded by sandwiching the electrode body from above and below using two laminated films, or the periphery may be welded by bending one laminated film and sandwiching the electrode body therebetween. Good.
The welding method is not particularly limited, and an impulse method, a hot plate method, a high-frequency induction heating method, an ultrasonic induction heating method, or the like can be used.
以下に実施例を用いて本発明をさらに詳しく説明するが、本発明はこれら実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
（実施例１）
正極集電体としての厚さ１５μｍのアルミニウム箔の両面に、リチウムニッケルコバルトアルミニウム系酸化物（ＮＣＡ）、導電助剤（カーボンナノチューブ）、バインダー（ポリフッ化ビニリデン）、溶媒（Ｎ−メチルピロリドン）とを混合した組成物を塗布し、１２０℃で真空乾燥した。これにより、ＮＣＡ９２質量％、導電助剤４質量％、バインダー４質量％の正極活物質層が正極集電体上の両面に形成された正極を得た。なお、正極活物質層の厚さは、それぞれ４５μｍであった。
絶縁性微粒子（アルミナ粒子）、バインダー（ポリフッ化ビニリデンヘキサフルオロプロピレン共重合体）、溶媒（Ｎ−メチルピロリドン）を混合し、攪拌機で３０分間穏やかに攪拌し、目開き８０μｍのフィルターでろ過し、接着層用組成物を得た。
得られた接着層用組成物を、バーコーターで、上記正極活物質層の表面全体に塗布した。組成物を塗布して形成した塗膜を６０℃で乾燥することによって、正極活物質層の表面に接着層を形成し、接着層を有する正極を得た。接着層の全体積に対するバインダーの含有量は、１５体積％であり、絶縁性微粒子の含有量は、８５体積％であった。接着層の厚みを測定したところ、それぞれ４μｍであった。
該接着層を有する正極を切り出し、縦９８ｍｍ、横９８ｍｍの同サイズの正極を２０枚得て、これらを積層した後、１００℃でヒートプレスして、評価用電極体を得た。
該評価用電極体を、２枚の積層フィルム［外面層（ポリエチレンテレフタレート）３０μｍ、中層（アルミニウム箔）４０μｍ、内面層（ポリプロピレン）８０μｍ）］で内面層同士を対向させて挟み込み、周縁を圧力０．５ＭＰａ、温度１８０℃、時間２ｓｅｃの条件でヒートシールした後に、積層フィルムの重なり合った部分の周縁を切断して成形した。これにより、評価用電極体をラミネート外装体に収容した評価用試料を得た。ラミネート外装体の溶着部の幅は１ｍｍであり、溶着部の幅は、ラミネート外装体の長手方向の長さの０．０１倍であった。
なお、本実施例１及びその他の実施例、比較例では、実験の簡略化のために、評価用電極体は、負極を用いず正極のみを積層して形成しているが、接着層の有無、溶着部の幅以外は同条件であるため、接着層の有無、溶着部の幅の影響を適切に評価できている。
(Example 1)
A lithium nickel cobalt aluminum oxide (NCA), a conductive additive (carbon nanotube), a binder (polyvinylidene fluoride), and a solvent (N-methylpyrrolidone) Was applied and vacuum dried at 120 ° C. As a result, a positive electrode having 92% by mass of NCA, 4% by mass of a conductive additive, and 4% by mass of a binder, having a positive electrode active material layer formed on both surfaces of a positive electrode current collector, was obtained. The thickness of each of the positive electrode active material layers was 45 μm.
Insulating fine particles (alumina particles), a binder (polyvinylidene fluoride hexafluoropropylene copolymer), and a solvent (N-methylpyrrolidone) were mixed, gently stirred with a stirrer for 30 minutes, and filtered with a filter having an aperture of 80 μm. An adhesive layer composition was obtained.
The obtained composition for an adhesive layer was applied to the entire surface of the positive electrode active material layer using a bar coater. By drying the coating film formed by applying the composition at 60 ° C., an adhesive layer was formed on the surface of the positive electrode active material layer, and a positive electrode having an adhesive layer was obtained. The content of the binder relative to the total volume of the adhesive layer was 15% by volume, and the content of the insulating fine particles was 85% by volume. When the thickness of the adhesive layer was measured, it was 4 μm each.
The positive electrode having the adhesive layer was cut out to obtain 20 positive electrodes of the same size having a length of 98 mm and a width of 98 mm, which were laminated and then heat-pressed at 100 ° C. to obtain an electrode body for evaluation.
The electrode body for evaluation is sandwiched between two laminated films [the outer layer (polyethylene terephthalate) 30 μm, the middle layer (aluminum foil) 40 μm, the inner layer (polypropylene) 80 μm)] with the inner layers facing each other, and the periphery is pressurized to 0. After heat-sealing under the conditions of 0.5 MPa, a temperature of 180 ° C., and a time of 2 sec, the peripheral edge of the overlapping portion of the laminated film was cut and molded. As a result, a sample for evaluation in which the electrode body for evaluation was accommodated in the laminate outer package was obtained. The width of the welded portion of the laminate exterior body was 1 mm, and the width of the welded portion was 0.01 times the length in the longitudinal direction of the laminate exterior body.
In Example 1, the other Examples, and Comparative Examples, the electrode body for evaluation was formed by laminating only the positive electrode without using the negative electrode for simplification of the experiment. Since the conditions are the same except for the width of the welded portion, the effects of the presence or absence of the adhesive layer and the width of the welded portion can be appropriately evaluated.
（実施例２）
実施例１において、ラミネート外装体の溶着部の幅を５ｍｍとし、溶着部の幅を、ラミネート外装体の長手方向の長さの０．０５倍とした以外は、実施例１と同様にして、評価用試料を得た。
(Example 2)
In Example 1, in the same manner as in Example 1, except that the width of the welded portion of the laminate exterior body was set to 5 mm and the width of the welded portion was set to 0.05 times the length in the longitudinal direction of the laminate exterior body, An evaluation sample was obtained.
（比較例１）
実施例１において、正極活物質層の表面に接着層を形成させない以外は、実施例１と同様にして、評価用試料を得た。ラミネート外装体の溶着部の幅は１ｍｍであり、溶着部の幅は、ラミネート外装体の長手方向の長さの０．０１倍であった。
(Comparative Example 1)
A sample for evaluation was obtained in the same manner as in Example 1 except that the adhesive layer was not formed on the surface of the positive electrode active material layer. The width of the welded portion of the laminate exterior body was 1 mm, and the width of the welded portion was 0.01 times the length in the longitudinal direction of the laminate exterior body.
（比較例２）
比較例１において、ラミネート外装体の溶着部の幅を５ｍｍとし、溶着部の幅を、ラミネート外装体の長手方向の長さの０．０５倍とした以外は、比較例１と同様にして、評価用試料を得た。
(Comparative Example 2)
In Comparative Example 1, in the same manner as in Comparative Example 1, except that the width of the welded portion of the laminate exterior body was 5 mm and the width of the welded portion was 0.05 times the length of the laminate exterior body in the longitudinal direction, An evaluation sample was obtained.
（比較例３）
実施例１において、ラミネート外装体の溶着部の幅を０．５ｍｍとし、溶着部の幅を、ラミネート外装体の長手方向の長さの０．００５倍とした以外は、実施例１と同様にして、評価用試料を得た。
(Comparative Example 3)
In the same manner as in Example 1, except that the width of the welded portion of the laminate exterior body was set to 0.5 mm and the width of the welded portion was set to 0.005 times the length of the laminate exterior body in the longitudinal direction. Thus, an evaluation sample was obtained.
（評価）
以下の方法により、各評価用試料のラミネート外装体の溶着部の強度を評価した。
ラミネート外装体を、中空上の円柱形状を有する載置台（直径：８０ｍｍ、高さ：１００ｍｍ、材質：樹脂）に置いた。この際、ラミネート外装体の中央部と、載置台の中央部とが一致するようにして、ラミネート外装体を載置台の上に置いた。その後、ラミネート外装体の扁平面の中央部に、ステンレス製の棒（直径：２５ｍｍ）を０．０２ＭＰａの条件で押圧し、ラミネート外装体を破壊した。この際、ラミネート外装体の中央部を押圧することによって中央部が歪み、その歪みが中央部から溶着部にまで伝播することにより、溶着部において折れ曲がる箇所（破壊箇所）が発生した。本評価においては、ラミネート外装体の溶着部に発生した折れ曲がり箇所（破壊箇所）の個数の大小により、溶着部の強度を検証した。
(Evaluation)
The strength of the welded portion of the laminate outer package of each evaluation sample was evaluated by the following method.
The laminated exterior body was placed on a mounting table (diameter: 80 mm, height: 100 mm, material: resin) having a hollow cylindrical shape. At this time, the laminate exterior body was placed on the placement table such that the center of the laminate exterior body coincided with the center of the mounting table. Thereafter, a stainless steel rod (diameter: 25 mm) was pressed against the center of the flat surface of the laminate exterior under a condition of 0.02 MPa to break the laminate exterior. At this time, the central portion of the laminate exterior body was pressed to deform the central portion, and the distortion propagated from the central portion to the welded portion, so that a bent portion (a broken portion) occurred at the welded portion. In this evaluation, the strength of the welded portion was verified based on the number of bent portions (broken portions) generated in the welded portion of the laminate exterior body.
各実施例の結果より、溶着部の幅が一定範囲内にある本発明の蓄電素子は、破壊箇所の個数が少なく、溶着部の強度が高かった。
一方、溶着部の幅が一定範囲内にない各比較例の蓄電素子は、破壊箇所の個数が多く、溶着部の強度が低かった。
According to the results of the examples, in the power storage device of the present invention in which the width of the welded portion was within a certain range, the number of broken portions was small and the strength of the welded portion was high.
On the other hand, in the power storage device of each comparative example in which the width of the welded portion was not within the fixed range, the number of broken portions was large, and the strength of the welded portion was low.
１０ 蓄電素子
１１ ラミネート外装体
１２ 正極集電板
１３ 負極集電板
１４ 積層フィルム
１５ プラスチックフィルム
１６ 金属層
１７ プラスチックフィルム
２０ 電極体
２０’ 電極体
２１ 正極活物質層
２２ 正極集電体
２３ 正極
２４ 接着層
２５ セパレータ
２５Ａ 平面部
２５Ｂ 屈曲部
２６ 負極活物質層
２７ 負極集電体
２８ 負極
２９ 溶着部
DESCRIPTION OF SYMBOLS 10 Power storage element 11 Laminate exterior body 12 Positive electrode current collector 13 Negative electrode current collector 14 Laminated film 15 Plastic film 16 Metal layer 17 Plastic film 20 Electrode body 20 'Electrode body 21 Positive active material layer 22 Positive electrode collector 23 Positive electrode 24 Adhesion Layer 25 Separator 25A Flat part 25B Bent part 26 Negative electrode active material layer 27 Negative current collector 28 Negative electrode 29 Welded part
Claims (9)
前記電極体が、正極と、負極と、前記正極と負極との間に配置される接着層とを備えており、
前記ラミネート外装体の周縁には、プラスチックフィルム同士が溶着された溶着部が設けられており、
前記溶着部の幅が、ラミネート外装体の長手方向の長さの０．００８〜０．０６倍である、蓄電素子。 A laminate exterior body including a plastic film as an inner layer, a power storage element containing an electrode body,
The electrode body includes a positive electrode, a negative electrode, and an adhesive layer disposed between the positive electrode and the negative electrode,
At the periphery of the laminate exterior body, a welded portion where plastic films are welded to each other is provided,
The power storage element, wherein a width of the welded portion is 0.008 to 0.06 times a length in a longitudinal direction of the laminate exterior body.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998048466A1 (en) * | 1997-04-23 | 1998-10-29 | Japan Storage Battery Co., Ltd. | Electrode and battery |
| JP3426253B2 (en) * | 1998-01-19 | 2003-07-14 | 三菱電機株式会社 | Battery |
| JP2006066311A (en) * | 2004-08-30 | 2006-03-09 | Shin Kobe Electric Mach Co Ltd | Lithium secondary battery |
| JP2011204604A (en) * | 2010-03-26 | 2011-10-13 | Sony Corp | Battery pack and method of manufacturing the same |
| WO2011126047A1 (en) * | 2010-04-06 | 2011-10-13 | 住友電気工業株式会社 | Method for producing separator, method for manufacturing molten salt battery, separator, and molten salt battery |
| WO2012144007A1 (en) * | 2011-04-18 | 2012-10-26 | エリーパワー株式会社 | Device for producing and method for producing secondary battery |
| JP2016189300A (en) * | 2015-03-30 | 2016-11-04 | パナソニックＩｐマネジメント株式会社 | Thin battery |
| JP2016192404A (en) * | 2015-03-30 | 2016-11-10 | 大日本印刷株式会社 | Cell packaging material, method for producing the same, and cell |
-
2018
- 2018-07-25 JP JP2018139226A patent/JP2020017398A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998048466A1 (en) * | 1997-04-23 | 1998-10-29 | Japan Storage Battery Co., Ltd. | Electrode and battery |
| JP3426253B2 (en) * | 1998-01-19 | 2003-07-14 | 三菱電機株式会社 | Battery |
| JP2006066311A (en) * | 2004-08-30 | 2006-03-09 | Shin Kobe Electric Mach Co Ltd | Lithium secondary battery |
| JP2011204604A (en) * | 2010-03-26 | 2011-10-13 | Sony Corp | Battery pack and method of manufacturing the same |
| WO2011126047A1 (en) * | 2010-04-06 | 2011-10-13 | 住友電気工業株式会社 | Method for producing separator, method for manufacturing molten salt battery, separator, and molten salt battery |
| WO2012144007A1 (en) * | 2011-04-18 | 2012-10-26 | エリーパワー株式会社 | Device for producing and method for producing secondary battery |
| JP2016189300A (en) * | 2015-03-30 | 2016-11-04 | パナソニックＩｐマネジメント株式会社 | Thin battery |
| JP2016192404A (en) * | 2015-03-30 | 2016-11-10 | 大日本印刷株式会社 | Cell packaging material, method for producing the same, and cell |
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| CN115149077A (en) * | 2021-03-30 | 2022-10-04 | 本田技研工业株式会社 | Battery cell and method for manufacturing same |
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