JP2019121471A - Positive electrode mixture paste for lithium ion battery, and manufacturing method thereof - Google Patents
Positive electrode mixture paste for lithium ion battery, and manufacturing method thereof Download PDFInfo
- Publication number
- JP2019121471A JP2019121471A JP2017254068A JP2017254068A JP2019121471A JP 2019121471 A JP2019121471 A JP 2019121471A JP 2017254068 A JP2017254068 A JP 2017254068A JP 2017254068 A JP2017254068 A JP 2017254068A JP 2019121471 A JP2019121471 A JP 2019121471A
- Authority
- JP
- Japan
- Prior art keywords
- positive electrode
- organic polymer
- mass
- electrode mixture
- mixture paste
- 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.)
- Granted
Links
- 239000000203 mixture Substances 0.000 title claims abstract description 156
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 53
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims description 21
- 229920000620 organic polymer Polymers 0.000 claims abstract description 103
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims abstract description 72
- 239000007787 solid Substances 0.000 claims abstract description 37
- 239000011230 binding agent Substances 0.000 claims abstract description 35
- 239000004020 conductor Substances 0.000 claims abstract description 33
- 238000000034 method Methods 0.000 claims abstract description 30
- 238000003860 storage Methods 0.000 claims abstract description 24
- 239000007788 liquid Substances 0.000 claims abstract description 17
- 239000007774 positive electrode material Substances 0.000 claims description 63
- 238000002156 mixing Methods 0.000 claims description 15
- 239000000654 additive Substances 0.000 claims description 14
- 230000000996 additive effect Effects 0.000 claims description 13
- 230000001747 exhibiting effect Effects 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims description 4
- 239000002131 composite material Substances 0.000 claims description 4
- RSNHXDVSISOZOB-UHFFFAOYSA-N lithium nickel Chemical compound [Li].[Ni] RSNHXDVSISOZOB-UHFFFAOYSA-N 0.000 claims description 3
- 238000001879 gelation Methods 0.000 abstract description 10
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 abstract 1
- 239000005977 Ethylene Substances 0.000 abstract 1
- 239000013543 active substance Substances 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 38
- 239000002002 slurry Substances 0.000 description 20
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 230000008719 thickening Effects 0.000 description 7
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 239000008151 electrolyte solution Substances 0.000 description 6
- 230000001965 increasing effect Effects 0.000 description 6
- -1 lithium-nickel transition metal Chemical class 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 5
- 239000002033 PVDF binder Substances 0.000 description 5
- 229910052744 lithium Inorganic materials 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- 238000005227 gel permeation chromatography Methods 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 3
- 229920002125 Sokalan® Polymers 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229920006037 cross link polymer Polymers 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 239000004584 polyacrylic acid Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 239000006230 acetylene black Substances 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 239000002041 carbon nanotube Substances 0.000 description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003480 eluent Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- AMXOYNBUYSYVKV-UHFFFAOYSA-M lithium bromide Chemical compound [Li+].[Br-] AMXOYNBUYSYVKV-UHFFFAOYSA-M 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000002905 metal composite material Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000008363 phosphate buffer Substances 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 239000012779 reinforcing material Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 1
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 1
- 229920006369 KF polymer Polymers 0.000 description 1
- 229910013063 LiBF 4 Inorganic materials 0.000 description 1
- 229910013684 LiClO 4 Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 150000004696 coordination complex Chemical class 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 150000005676 cyclic carbonates Chemical class 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 150000008040 ionic compounds Chemical class 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 210000003097 mucus Anatomy 0.000 description 1
- 235000013557 nattō Nutrition 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- HNJBEVLQSNELDL-UHFFFAOYSA-N pyrrolidin-2-one Chemical compound O=C1CCCN1 HNJBEVLQSNELDL-UHFFFAOYSA-N 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000013112 stability test Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
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
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
本発明は、リチウムイオン電池用正極合剤ペースト及びその製造方法、当該リチウムイオン電池用正極合剤ペーストを用いて製造された正極合剤層を含む、リチウムイオン電池用電極及びリチウムイオン電池、並びにリチウムイオン電池用正極合剤ペーストの保存安定性向上方法に関する。 The present invention relates to a positive electrode mixture paste for lithium ion battery and a method for producing the same, a lithium ion battery electrode and a lithium ion battery including a positive electrode mixture layer manufactured using the positive electrode mixture paste for lithium ion battery, and The present invention relates to a method for improving the storage stability of a positive electrode material mixture paste for lithium ion batteries.
リチウムイオン電池は、鉛蓄電池やニッケル水素電池等に比べ、重量や体積当たりのエネルギー密度が高いため、搭載電子機器の小型化、軽量化に寄与している。近年、自動車のゼロエミッションにむけた取り組みとして、ハイブリッド自動車や電機自動車が普及してきており、その燃費向上や走行距離の延長にリチウムイオン電池の性能アップが重要なカギとなっている。 Lithium ion batteries have higher energy density per unit weight and volume than lead storage batteries and nickel hydrogen batteries, and so contribute to the downsizing and weight reduction of mounted electronic devices. In recent years, hybrid cars and electric cars have been widely used as an approach for zero emission of cars, and the performance improvement of lithium ion batteries is important for improving the fuel efficiency and extending the driving distance.
リチウムイオン電池は、一般的に、正極、セパレータ、負極の３層構造に非水系電解液が満たされた構造を有している。正極及び負極は、例えば、活物質と導電材とバインダーを混合した合剤ペーストを集電体に塗工して製造される。現在、負極の製造方法としては、集電体となる銅箔に水系スラリー（合剤ペースト）を塗工乾燥する水系プロセスが主流であり、正極の製造方法としては、溶媒としてＮ−メチルピロリドン等の有機溶媒を用いて正極合剤ペーストを作製し、集電体となるアルミニウム箔に塗工する非水系プロセスが主流である。 A lithium ion battery generally has a structure in which a non-aqueous electrolytic solution is filled in a three-layer structure of a positive electrode, a separator, and a negative electrode. The positive electrode and the negative electrode are manufactured, for example, by coating a current collector with a mixture paste in which an active material, a conductive material, and a binder are mixed. At present, an aqueous process in which an aqueous slurry (mixture paste) is coated and dried on a copper foil serving as a current collector is mainly used as a method of manufacturing a negative electrode, and as a method of manufacturing a positive electrode, N-methylpyrrolidone etc. is used as a solvent The non-aqueous process of producing the positive mix paste using the organic solvent of, and applying to the aluminum foil used as a collector is the mainstream.
近年、高容量のリチウムイオン二次電池を得ることを目的として、ニッケルやマンガンを多く含むアルカリ性の高い正極活物質が使用されるようになってきているが、そのような正極活物質を使用した場合、正極合剤ペーストが、徐々に流動性を失い、増粘し、ゲル化するという問題が生じる。正極合剤ペーストが流動性を失うと、均質な塗工厚さを得ることが困難となるだけでなく、場合によっては、塗布が行えなくなり材料の無駄が生じてしまうことにもつながる。特に、リチウムニッケル遷移金属複合酸化物はこの問題が顕著に表れる。 In recent years, a highly alkaline positive electrode active material containing a large amount of nickel and manganese has come to be used for the purpose of obtaining a high capacity lithium ion secondary battery, but such a positive electrode active material was used. In this case, there is a problem that the positive electrode mixture paste gradually loses fluidity, thickens, and gels. When the positive electrode mixture paste loses its fluidity, it not only becomes difficult to obtain a uniform coating thickness, but in some cases, it can not be applied and leads to waste of material. In particular, lithium-nickel transition metal complex oxides exhibit this problem remarkably.
この問題を解決するため、例えば、特許文献１には、水に分散しても強いアルカリ性を示さないように正極合剤ペーストの調製を行うことで、正極合剤ペーストのゲル化を抑制する技術等が開示されている。 In order to solve this problem, for example, Patent Document 1 discloses a technology for suppressing the gelation of the positive electrode mixture paste by preparing the positive electrode mixture paste so as not to show strong alkalinity even when dispersed in water. Etc. are disclosed.
しかし、特許文献１に記載の方法で、強いアルカリ性を示さないように正極合剤ペーストを調製することは、厳格なｐＨ管理が必要となるだけでなく、正極活物質を一度水に分散し、分散液から濾過して正極活物質を取り出し乾燥をするという処理が必要であり、作業の煩雑さや歩留まりの低下を招いてしまう。また、前記のような処理を行うことで、正極活物質自体の性能低下も引き起こしてしまう可能性もある。 However, preparing the positive electrode material mixture paste so as not to show strong alkalinity by the method described in Patent Document 1 requires not only strict pH control but also dispersing the positive electrode active material in water once, A process of filtering out the dispersion liquid and taking out the positive electrode active material and drying it is necessary, which causes the complexity of the operation and the reduction of the yield. Moreover, there is also a possibility that performance degradation of the positive electrode active material itself may be caused by performing the above-mentioned treatment.
本発明は、簡便な方法により、増粘及びゲル化を抑制して、保存安定性が向上し且つ固形分の高濃度化が可能な、リチウムイオン電池用正極合剤ペーストを提供する。 The present invention provides a positive electrode mixture paste for a lithium ion battery, which is improved in storage stability and can increase the concentration of solid content by suppressing thickening and gelation by a simple method.
本発明は、一態様において、正極活物質、導電材、バインダー、有機ポリマー、及びNメチルピロリドンを含有し、前記有機ポリマーが、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストに関する。 The present invention, in one aspect, contains a positive electrode active material, a conductive material, a binder, an organic polymer, and N methyl pyrrolidone, and the organic polymer has a concentration of 0.001% by mass to 3% by mass and a liquid temperature The present invention relates to a positive electrode mixture paste for a lithium ion battery, which is an organic polymer exhibiting spinnability in an N-methylpyrrolidone solution at 25 ° C.
本発明は、別の態様において、有機ポリマーとNメチルピロリドンを含み、前記有機ポリマーがNメチルピロリドンに溶解しており、前記有機ポリマーが、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、添加剤組成物に関する。 In another aspect, the present invention comprises an organic polymer and N methyl pyrrolidone, wherein the organic polymer is dissolved in N methyl pyrrolidone, and the organic polymer has a concentration of 0.001% by mass to 3% by mass. The present invention relates to an additive composition which is an organic polymer exhibiting spinnability in a solution of N-methylpyrrolidone at a liquid temperature of 25 ° C.
本発明は、別の態様において、リチウムイオン電池用正極合剤ペーストの製造方法であり、正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを混合する工程を含み、前記有機ポリマーは、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの製造方法に関する。 The present invention, in another aspect, is a method for producing a positive electrode mixture paste for lithium ion batteries, comprising the step of mixing a positive electrode active material, a conductive material, a binder, an organic polymer, and N-methylpyrrolidone. The above-mentioned organic polymer is an organic polymer which exhibits spinnability in N methyl pyrrolidone solution whose concentration is 0.001 mass% or more and 3 mass% or less and the liquid temperature is 25 ° C., positive electrode mixture for lithium ion battery It relates to a method of producing a paste.
本発明は、更に別の態様において、正極活物質と導電材とバインダーとNメチルピロリドンとを含むリチウムイオン電池用正極合剤ペーストの保存安定性の向上方法であり、前記リチウムイオン電池用正極合剤ペーストの製造過程で、正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを混合する工程を含み、前記有機ポリマーは、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの保存安定性の向上方法に関する。 The present invention, in still another aspect, is a method for improving the storage stability of a positive electrode material mixture paste for lithium ion batteries containing a positive electrode active material, a conductive material, a binder, and N methyl pyrrolidone, Process of mixing the positive electrode active material, the conductive material, the binder, the organic polymer, and N methyl pyrrolidone in the production process of the agent paste, wherein the concentration of the organic polymer is 0.001 mass% or more and 3 mass The present invention relates to a method for improving the storage stability of a positive electrode material mixture paste for a lithium ion battery, which is an organic polymer exhibiting spinnability in an N-methylpyrrolidone solution having a solution temperature of 25 ° C. or less.
本発明は、更に別の態様において、本発明のリチウムイオン電池用正極合剤ペーストを用いて形成された正極合剤層を含む、リチウムイオン電池用電極に関する。 The present invention relates, in yet another aspect, to a lithium ion battery electrode including a positive electrode mixture layer formed using the positive electrode mixture paste for a lithium ion battery of the present invention.
本発明は、更に別の態様において、本発明のリチウムイオン電池用正極合剤ペーストを用いて形成された正極合剤層を含む、リチウムイオン電池に関する。 In still another aspect, the present invention relates to a lithium ion battery including a positive electrode mixture layer formed using the positive electrode mixture paste for a lithium ion battery of the present invention.
本発明によれば、簡便な方法により、増粘及びゲル化を抑制して、保存安定性が向上し且つ固形分の高濃度化が可能な、リチウムイオン電池用正極合剤ペーストを提供できる。また、正極合剤ペーストの増粘及びゲル化が抑制されるので、正極合剤ペースト中における、正極活物質及び導電材等の固形分の分散性が良好となり、均質な正極合剤層を形成することが可能となるので、リチウムイオン電池用電極及びリチウムイオン電池の品質向上が期待できる。 According to the present invention, it is possible to provide a positive electrode mixture paste for a lithium ion battery, which can suppress thickening and gelation by a simple method, improve storage stability, and increase the solid concentration. In addition, since thickening and gelation of the positive electrode mixture paste are suppressed, the dispersibility of solid components such as the positive electrode active material and the conductive material in the positive electrode mixture paste becomes good, and a homogeneous positive electrode mixture layer is formed. It is possible to improve the quality of the lithium ion battery electrode and the lithium ion battery.
本発明は、リチウムイオン電池用正極合剤ペーストが、下記の曳糸性を示す有機ポリマーを含むことで、リチウムイオン電池用正極合剤ペーストの、増粘及びゲル化等の経時劣化が抑制される結果、保存安定性が向上し且つ固形分の高濃度化も可能となる、という知見に基づく。 In the present invention, when the positive electrode mixture paste for lithium ion batteries contains the following organic polymer exhibiting spinnability, deterioration of the positive electrode mixture paste for lithium ion batteries with time such as thickening and gelation is suppressed. As a result, the storage stability is improved and it is possible to increase the solid content.
すなわち、本発明は、一実施形態において、正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを含むリチウムイオン電池用正極合剤ペーストであって、有機ポリマーが、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマー（以下「曳糸性有機ポリマー」と略称する場合もある。）である、リチウムイオン電池用正極合剤ペースト（以下、「正極合剤ペースト」と略称する場合もある。）に関する。「有機ポリマーが、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマー」であるとは、前記有機ポリマーの濃度が０．００１質量％以上３質量％以下のいずれかの濃度であり且つ液温が２５℃のNメチルピロリドン溶液が曳糸性を示すことを意味する。 That is, in one embodiment, the present invention is a positive electrode mixture paste for lithium ion batteries, comprising a positive electrode active material, a conductive material, a binder, an organic polymer, and N-methylpyrrolidone, wherein the organic polymer is In the N-methylpyrrolidone solution having a concentration of 0.001% by mass or more and 3% by mass or less and a liquid temperature of 25 ° C., an organic polymer exhibiting spinnability (hereinafter referred to as “spinning organic polymer”) may be abbreviated. And a positive electrode material mixture paste for lithium ion battery (hereinafter sometimes may be abbreviated as “positive electrode mixture paste”). “The organic polymer is an organic polymer exhibiting spinnability in an N-methylpyrrolidone solution having a concentration of 0.001% to 3% by mass and a liquid temperature of 25 ° C.” This means that the N-methylpyrrolidone solution having a concentration of 0.001% to 3% by mass and a liquid temperature of 25 ° C. exhibits spinnability.
本発明の効果発現のメカニズムの詳細は明らかではないが、以下のことが推定される。本発明では、正極合剤ペーストに曳糸性有機ポリマーが含まれていることにより、曳糸性有機ポリマーが、その溶媒であるNメチルピロリドン中に含まれる微量の水との相互作用（例えば水素結合）により高分子ネットワークを形成して、水を拘束し、正極活物質であるリチウム金属複合酸化物に含まれるＬｉＯ2等のアルカリ成分と水との反応を抑制することによって、増粘及びゲル化の抑制が可能となり、保存安定性を向上したものと考えられる。このように、正極合剤ペーストの増粘及びゲル化が抑制されるので、正極合剤ペースト中における、正極活物質及び導電材等の固形分の分散性が良好となるので、均質な正極合剤層を形成することが可能となる。また、正極合剤ペーストにおける固形分の濃度を向上することも可能となる。このように、本発明によれば、正極合剤ペーストの製造過程で、曳糸性有機ポリマーを添加し混合するという簡単な方法により、正極合剤ペーストの保存安定性を向上できるし、正極合剤ペーストにおける固形分の高濃度化も可能となる。したがって、本発明の正極合剤ペーストをリチウムイオン電池用電極（正極）の作製に用いた場合、リチウムイオン電池の製造におけるコスト低減を図ることができると考えられる。正極合剤ペーストにおける固形分の濃度を上げられるため、Nメチルピロリドンの使用量を低減でき、更にそれを除去するための乾燥に必要なエネルギーを低減でき、コスト低減を図ることができる。但し、これらは推定であって、本発明はこれらメカニズムに限定して解釈されない。 Although the details of the mechanism of the effect expression of the present invention are not clear, the following can be presumed. In the present invention, since the positive electrode mixture paste contains the spinnable organic polymer, the spinnable organic polymer interacts with a small amount of water contained in the solvent N-methylpyrrolidone (for example, hydrogen ) To form a polymer network, thereby constraining water and suppressing the reaction of water with an alkaline component such as LiO 2 contained in the lithium metal composite oxide that is a positive electrode active material, thereby thickening and forming a gel. Can be suppressed, and it is considered that storage stability is improved. As described above, since thickening and gelation of the positive electrode mixture paste are suppressed, the dispersibility of solid components such as the positive electrode active material and the conductive material in the positive electrode mixture paste is improved, so that uniform positive electrode synthesis is achieved. It becomes possible to form an agent layer. In addition, it is also possible to improve the concentration of solid content in the positive electrode mixture paste. As described above, according to the present invention, the storage stability of the positive electrode mixture paste can be improved by a simple method of adding and mixing the spinnable organic polymer in the process of manufacturing the positive electrode mixture paste. It is also possible to increase the solid content of the agent paste. Therefore, when the positive electrode material mixture paste of the present invention is used for producing a lithium ion battery electrode (positive electrode), it is considered that cost reduction in manufacturing of a lithium ion battery can be achieved. Since the concentration of solid content in the positive electrode mixture paste can be increased, the amount of N methyl pyrrolidone used can be reduced, the energy required for drying to remove it can be reduced, and the cost can be reduced. However, these are only estimates, and the present invention is not interpreted as being limited to these mechanisms.
本発明の正極合剤ペーストは、正極活物質と、導電材と、バインダーと、曳糸性有機ポリマーと、Nメチルピロリドンと、必要に応じて添加されるその他の成分とを含有する。本発明の正極合剤ペーストに含まれる正極活物質、導電材、及びバインダー（結着材）の質量比は、従来公知の電池の場合と同じでよく、電池の使用適性に応じて任意に調整できる。前記その他の成分としては、例えば増粘剤、補強材、酸化防止剤、電解液の分解を抑制する機能を有する添加剤などが例示され、これらの他の成分は、公知のものを使用することができる。 The positive electrode material mixture paste of the present invention contains a positive electrode active material, a conductive material, a binder, a spinnable organic polymer, N-methyl pyrrolidone, and other components added as needed. The mass ratio of the positive electrode active material, the conductive material, and the binder (binder) contained in the positive electrode material mixture paste of the present invention may be the same as in the case of the conventionally known battery, and may be arbitrarily adjusted according to the use aptitude of the battery it can. Examples of the other components include thickeners, reinforcing materials, antioxidants, additives having a function of suppressing the decomposition of the electrolyte, and the like, and these other components may be known ones. Can.
［正極活物質］
正極活物質としては、リチウムを吸蔵、放出可能であって、充放電反応が可能である活物質であればよく、例えば、ＬｉＣｏＯ2、ＬｉＮｉＯ2、Ｌｉ2ＭｎＯ4、Ｌｉリッチ形（Ｌｉ（ＬｉxＭｅ1-x）Ｏ2（Ｍｅ＝Ｃｏ,Ｎｉ,Ｍｎ）等のリチウム金属複合酸化物が挙げられる。これら化合物は部分的に元素置換したものであってもよい。特に、ＬｉＯ2等のアルカリ成分を多く含む、ＬｉＮｉＯ2を主成分とするリチウムニッケル含有複合酸化物（ＬｉＮｉＯ2系）やＬｉリッチ形を主成分とするリチウム金属複合酸化物を正極活物質として用いる場合に、本発明は有効に利用されうる。正極活物質は粒状物として用いられる。その平均粒径としては、例えば、２μｍ以上４０μｍ以下とすることができる。
[Positive electrode active material]
The positive electrode active material may be any active material capable of inserting and extracting lithium and capable of charge and discharge reaction, for example, LiCoO 2 , LiNiO 2 , Li 2 MnO 4 , Li rich type (Li (Li (Li (Li (Li Examples thereof include lithium metal complex oxides such as x Me 1-x ) O 2 (Me = Co, Ni, Mn), etc. These compounds may be partially element-substituted, in particular, LiO 2 etc. when using includes many alkaline components, lithium-nickel-containing composite oxide composed mainly of LiNiO 2 (LiNiO 2 based) or Li lithium metal composite oxide composed mainly of rich shape as the positive electrode active material, the present invention is The positive electrode active material is used as particles, and the average particle diameter thereof can be, for example, 2 μm or more and 40 μm or less.
本発明の正極合剤ペーストにおける正極活物質の含有量は、正極合剤ペーストの全固形分量に対し、高容量化の観点から、好ましくは８０質量％以上、より好ましくは９０質量％以上であり、そして、正極合剤層の集電体への結着力向上の観点から、好ましくは９９質量％以下、より好ましくは９８質量％以下である。 The content of the positive electrode active material in the positive electrode mixture paste of the present invention is preferably 80% by mass or more, more preferably 90% by mass or more, from the viewpoint of increasing the capacity with respect to the total solid content of the positive electrode mixture paste. And, from the viewpoint of improving the binding strength of the positive electrode mixture layer to the current collector, it is preferably 99% by mass or less, more preferably 98% by mass or less.
［導電材］
導電材は、充放電反応を効率的に行い、電気伝導性を高めるためのものであり、例えば、アセチレンブラック、ケッチェンブラック、黒鉛、ＣＮＴ（カーボンナノチューブ）等の炭素材料が挙げられ、これらは単独又は２種以上混合して用いることができる。
[Conductive material]
The conductive material is for efficiently performing charge / discharge reaction and enhancing the electrical conductivity, and examples thereof include carbon materials such as acetylene black, ketjen black, graphite, CNT (carbon nanotube), etc. It can be used alone or in combination of two or more.
本発明の正極合剤ペーストにおける導電材の含有量は、正極合剤ペーストの全固形分量に対し、導電性向上の観点から、好ましくは０．５質量％以上、より好ましくは１質量％以上であり、そして、電池容量向上の観点から、好ましくは１０質量％以下、より好ましくは５質量％以下である。 The content of the conductive material in the positive electrode mixture paste of the present invention is preferably 0.5% by mass or more, more preferably 1% by mass or more, from the viewpoint of improving the conductivity relative to the total solid content of the positive electrode mixture paste. And from the viewpoint of improving the battery capacity, it is preferably 10% by mass or less, more preferably 5% by mass or less.
［バインダー］
バインダーは、正極合剤層と集電体との間の接着機能を持たせるものであり、例えば、ポリフッ化ビニリデン（ＰＶＤＦ）が一般的に用いられる。ＰＶＤＦは、アルカリ成分によってゲル化がおこりやすい。また、Nメチルピロリドンには微量の水が含まれるため、当該水と正極活物質由来のアルカリ成分によってバインダーのゲル化を引き起こしやすい。したがって、バインダーとしてＰＶＤＦを用いる系において、本発明は顕著に有効である。
[binder]
The binder has an adhesive function between the positive electrode mixture layer and the current collector, and, for example, polyvinylidene fluoride (PVDF) is generally used. PVDF is prone to gelation due to the alkali component. In addition, since N-methylpyrrolidone contains a trace amount of water, the binder and the alkali component derived from the water and the positive electrode active material easily cause gelation of the binder. Therefore, the present invention is remarkably effective in a system using PVDF as a binder.
本発明の正極合剤ペーストにおけるバインダーの含有量は、正極合剤ペーストの全固形分量に対し、正極合剤層と集電体との結着力向上の観点から、好ましくは０．５質量％以上、より好ましくは１質量％以上であり、そして、電池容量向上の観点から、好ましくは１０質量％以下、より好ましくは５質量％以下である。 The content of the binder in the positive electrode mixture paste of the present invention is preferably 0.5% by mass or more from the viewpoint of improving the binding strength between the positive electrode mixture layer and the current collector with respect to the total solid content of the positive electrode mixture paste. More preferably, it is 1% by mass or more, and from the viewpoint of improving the battery capacity, it is preferably 10% by mass or less, more preferably 5% by mass or less.
［Nメチルピロリドン］
本発明の正極合剤ペーストは、正極活物質や導電材を分散可能とする分散媒として、そして、バインダーや曳糸性有機ポリマーを溶解可能とする溶媒として、Nメチルピロリドンを含む。本発明の正極合剤ペーストにおけるNメチルピロリドンの含有量は、正極合剤ペーストの塗工性の向上の観点から、好ましくは１０重量％以上、より好ましくは２０重量％以上であり、そして、同様の観点から、好ましくは５０重量％以下、より好ましくは４０重量％以下である。
[N methyl pyrrolidone]
The positive electrode mixture paste of the present invention contains N-methylpyrrolidone as a dispersion medium capable of dispersing the positive electrode active material and the conductive material, and as a solvent capable of dissolving the binder and the spinnable organic polymer. The content of N methyl pyrrolidone in the positive electrode mixture paste of the present invention is preferably 10% by weight or more, more preferably 20% by weight or more, from the viewpoint of improving the coatability of the positive electrode mixture paste. Preferably, it is 50% by weight or less, more preferably 40% by weight or less.
［曳糸性有機ポリマー］
本発明の正極合剤ペーストは、保存安定性向上及び正極合剤ペーストにおける固形分の高濃度化の観点から、曳糸性有機ポリマーを含有する。
[Spring thread organic polymer]
The positive electrode mixture paste of the present invention contains a spinnable organic polymer from the viewpoint of improving storage stability and increasing the solid content of the positive electrode mixture paste.
〔曳糸性の定義〕
ここで、曳糸性とは、物体の伸張特性が現れる、所謂、「糸を曳く」性質であり、例えば「納豆の糸曳き」等がその顕著な例として挙げられる。曳糸性は液状組成物を低速度で滴下又はその一端を保持して伸張した際に、破断して液滴を形成することなく連続した糸状構造体を呈する性質であり、例えば「動植物の粘液の糸曳き」等が例として挙げられる。ちなみに曳糸性は液状組成物の弾性的緩和現象のひとつであり、表面張力や粘度とは全く独立の物性であることが知られている。ここで、通常のポリマー溶液であっても、例えば濃度が１００ｇ／Ｌ以上の高濃度であれば、上記の曳糸性挙動を呈することはしばしばあるが、懸かる系は極めて粘度が高く、ポリマー溶液は著しく流動性に欠ける。本発明でいう曳糸性とは、特殊な有機ポリマーの非水系液状組成物が、極めて稀薄な濃度下で高い流動性を保ちながら発現し得る曳糸性を指す。
[Definition of spinnability]
Here, the spinnability is a so-called "threading" property in which the stretching property of the object appears, and for example, "natto threading" etc. can be mentioned as a prominent example. The spinnability is the property of exhibiting a continuous thread-like structure without breaking up and forming droplets when the liquid composition is dropped at a low speed or stretched while holding one end thereof, for example, “mucus of animals and plants "Yarning" etc. are mentioned as an example. Incidentally, spinnability is one of the elastic relaxation phenomena of liquid compositions, and it is known that surface tension and viscosity are physical properties completely independent of each other. Here, even if it is a normal polymer solution, for example, if the concentration is a high concentration of 100 g / L or more, the above-mentioned spinnable behavior is often exhibited, but the system in question is extremely high in viscosity and the polymer solution Are significantly less fluid. The spinnability referred to in the present invention refers to spinnability in which a non-aqueous liquid composition of a special organic polymer can be developed while maintaining high fluidity under extremely dilute concentration.
〔曳糸性有機ポリマーの定義〕
本発明でいう曳糸性有機ポリマーは、そのNメチルピロリドン溶液が前記の曳糸性を呈する有機ポリマーのことである。この曳糸性有機ポリマーは、一般に、高分子量の有機高分子が発現する所謂「増粘性有機ポリマー」とは異なる。本発明において曳糸性有機ポリマーは、その濃度が３質量％以下のNメチルピロリドン溶液が曳糸性を呈する有機ポリマーであり、好ましくはその濃度が１質量％以下のNメチルピロリドン溶液が曳糸性を呈する有機ポリマーであり、より好ましくはその濃度が０．５質量％以下のNメチルピロリドン溶液が曳糸性を呈する有機ポリマーである。そして、その濃度が０．００１質量％以上のNメチルピロリドン溶液中で曳糸性を呈する有機ポリマーであり、好ましくはその濃度が０．０１質量％以上のNメチルピロリドン溶液中で曳糸性を呈する有機ポリマーである。
[Definition of a spinnable organic polymer]
The spinnable organic polymer referred to in the present invention is an organic polymer whose N methyl pyrrolidone solution exhibits the above spinnability. The spinnable organic polymer is generally different from a so-called "thickening organic polymer" in which a high molecular weight organic polymer is expressed. In the present invention, the spinnable organic polymer is an organic polymer in which the N methyl pyrrolidone solution having a concentration of 3% by mass or less exhibits spinnability, and preferably, the N methyl pyrrolidone solution having a concentration of 1% by mass or less It is an organic polymer exhibiting a property, more preferably an N-methylpyrrolidone solution having a concentration of 0.5% by mass or less is an organic polymer exhibiting a spinnability. And it is an organic polymer which exhibits spinnability in N methyl pyrrolidone solution whose concentration is 0.001 mass% or more, preferably spinnability in N methyl pyrrolidone solution whose concentration is 0.01 mass% or more. It is an organic polymer to exhibit.
本発明において、有機ポリマーの曳糸性の有無は、以下の方法で判定する。有機ポリマー１重量部をNメチルピロリドン９９重量部に溶解させて得た有機ポリマーのNメチルピロリドン溶液を用いて、下記〔曳糸性判定法〕に準じた方法で判定し、曳糸性を有する場合、曳糸性有機ポリマーとする。 In the present invention, the spinnability of the organic polymer is determined by the following method. Using an N-methylpyrrolidone solution of an organic polymer obtained by dissolving 1 part by weight of an organic polymer in 99 parts by weight of N-methylpyrrolidone, it is determined by a method according to the following [Spinability evaluation method] and has spinnability In the case of spiny organic polymer.
〔曳糸性判定法〕
先端内径１ｍｍのパスツールピペット（ガラス、例えばＡＳＡＨＩＴＥＣＨＮＯ ＧＬＡＳＳ、ＩＫ−ＰＡＳ−５Ｐ）より静かに滴下操作をした際に、糸を曳いたNメチルピロリドン溶液を、本発明において曳糸性を示すNメチルピロリドン溶液とする。長く糸を曳く溶液を強い（又は高い）曳糸性を持つNメチルピロリドン溶液とする。Nメチルピロリドン溶液は２５℃で、よく攪拌して判定に用い、少なくともパスツールピペットの先端を落下地点から５ｍｍ離して滴下操作を行うこととする。曳糸性の強いNメチルピロリドン溶液に関しては、より高い位置から滴下操作を行うと、より確認しやすい。滴下操作は複数回行って確認しても構わない。通常、滴下操作の際に確認される「糸」は、１ｍｍより幅が細いものである。
[Method for determining spinnability]
The N methyl pyrrolidone solution in which the thread is twisted when it is dropped gently from a Pasteur pipette (glass such as ASAHITECHNO GLASS, IK-PAS-5P) with an inner diameter of 1 mm of the tip is N methyl showing the spinnability in the present invention. Make it a pyrrolidone solution. The long threading solution is made into a strong (or high) spinnable N methyl pyrrolidone solution. The N methyl pyrrolidone solution is well stirred at 25 ° C. and used for determination, and at least the tip of the Pasteur pipette is placed 5 mm away from the dropping point to perform the dropping operation. It is easier to confirm the dripping operation from a higher position for the strong N-methylpyrrolidone solution with high spinnability. The dropping operation may be performed a plurality of times to confirm. Usually, the "yarn" confirmed during the dropping operation is thinner than 1 mm.
曳糸性の付与効果が高いものほど、すなわち高曳糸性の有機ポリマーほど、より低濃度で目的とする、保存安定性の向上及び正極合剤ペーストにおける固形分の高濃度化を実現できる。 The higher the spinnability imparting effect, that is, the higher the spinnability of the organic polymer, the lower the concentration, and the desired improvement in storage stability and an increase in the solid concentration in the positive electrode mixture paste can be realized.
曳糸性有機ポリマーとしては、架橋型のポリマーと非架橋型ポリマーが挙げられ、中でも、非架橋型ポリマーほど高曳糸性であり、本発明において好ましい。 The spinnable organic polymer includes cross-linked polymers and non-cross-linked polymers. Among them, non-cross-linked polymers have higher spinnability and are preferred in the present invention.
曳糸性有機ポリマーは、保存安定性の向上及び正極合剤ペーストにおける固形分の高濃度化の観点から、好ましくはエチレンオキサイド（ＥＯ）に由来の構成単位を含むポリマーであり、より好ましくは、高い曳糸性を示すポリエチレンオキサイド（ＰＥＯ）である。 The spinnable organic polymer is preferably a polymer containing a structural unit derived from ethylene oxide (EO), from the viewpoint of improving storage stability and increasing the solid concentration in the positive electrode mixture paste, and more preferably, It is polyethylene oxide (PEO) that exhibits high spinnability.
曳糸性有機ポリマーの重量平均分子量は、正極合剤ペーストの電池の初期容量低下の抑制と保存安定性向上の観点から、好ましくは２２０万以上、より好ましくは２５０万以上、更に好ましくは３００万以上であり、そして、同様の観点から、好ましくは３０００万以下、より好ましくは２０００万以下、更に好ましくは１０００万以下である。なお、曳糸性有機ポリマーの重量平均分子量は、後述の実施例に記載の方法により測定できる。 The weight average molecular weight of the spinnable organic polymer is preferably 2.2 million or more, more preferably 2.5 million or more, still more preferably 3 million from the viewpoint of suppressing the decrease in initial capacity of the battery of the positive electrode mixture paste and improving storage stability. From the above and from the same viewpoint, it is preferably 30 million or less, more preferably 20 million or less, and still more preferably 10 million or less. In addition, the weight average molecular weight of a spinnable organic polymer can be measured by the method as described in the below-mentioned Example.
本発明の正極合剤ペーストにおける曳糸性有機ポリマーの含有量は、正極合剤ペーストの全固形分量に対して、正極合剤ペーストの保存安定性向上の観点から、好ましくは０．００１質量％以上、より好ましくは０．００５質量％以上であり、そして、電池の初期容量低下抑制の観点から好ましくは０．１質量％以下、より好ましくは０．０３質量％以下である。 The content of the spinnable organic polymer in the positive electrode mixture paste of the present invention is preferably 0.001% by mass from the viewpoint of improving the storage stability of the positive electrode mixture paste, with respect to the total solid content of the positive electrode mixture paste. The content is more preferably 0.005% by mass or more, and preferably 0.1% by mass or less, more preferably 0.03% by mass or less from the viewpoint of suppressing the decrease in initial capacity of the battery.
本発明の正極合剤ペーストにおける全固形分の濃度は、リチウムイオン電池の製造におけるコスト低減の観点から、好ましくは５０質量％以上、より好ましくは６０質量％以上、更に好ましくは６５質量％以上、更により好ましくは７０質量％以上であり、ペーストの良好な塗工性の確保の観点から、好ましくは９０質量％以下、より好ましくは８０質量％以下である。 The concentration of total solids in the positive electrode material mixture paste of the present invention is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, from the viewpoint of cost reduction in manufacturing lithium ion batteries. The content is more preferably 70% by mass or more, and preferably 90% by mass or less, and more preferably 80% by mass or less from the viewpoint of securing a good coating property of the paste.
［正極合剤ペーストの製造方法］
本発明は、一実施形態において、本発明の正極合剤ペーストの製造方法（以下、「本発明の製造方法」と略称する場合もある。）に関する。
[Method of producing positive electrode mixture paste]
The present invention relates, in one embodiment, to a method for producing a positive electrode mixture paste of the present invention (hereinafter sometimes referred to as “the method for producing the present invention”).
本発明の製造方法は、正極活物質と導電材とバインダーと曳糸性有機ポリマーとNメチルピロリドンとを混合する工程を含み、高濃度化の観点から、好ましくは、曳糸性有機ポリマー以外の固形分とNメチルピロリドンとを含む混合物、例えば、正極活物質と導電材とバインダーとNメチルピロリドンとを含む混合物に、曳糸性有機ポリマーのNメチルピロリドン溶液（添加剤組成物）を添加する工程を含む。本発明の正極合剤ペーストは、例えば、導電材とバインダーのNメチルピロリドン溶液を混合し、これらが均質になるまで攪拌してスラリー［１］を作製し、当該スラリー［１］に正極活物質と必要に応じてNメチルピロリドンを加えて均質になるまで攪拌してスラリー［２］とし、当該スラリー［２］に曳糸性有機ポリマーのNメチルピロリドン溶液を加え、均質になるまで攪拌することにより得ることができる。各成分の混合、スラリー［１］及びスラリー［２］の攪拌の手段には拘らない。例えば、自公転式攪拌機を用いることができる。 The production method of the present invention includes the step of mixing the positive electrode active material, the conductive material, the binder, the spinnable organic polymer, and N methyl pyrrolidone, and from the viewpoint of increasing the concentration, preferably other than spinnable organic polymer Add N methyl pyrrolidone solution (additive composition) of spinnable organic polymer to a mixture containing solid content and N methyl pyrrolidone, for example, a mixture containing a positive electrode active material, a conductive material, a binder, and N methyl pyrrolidone Including the steps. In the positive electrode material mixture paste of the present invention, for example, a conductive material and an N-methylpyrrolidone solution of a binder are mixed, and the mixture is stirred until it becomes homogeneous to prepare a slurry [1]. Add N methyl pyrrolidone as needed and stir until it becomes homogeneous to make a slurry [2], add N methyl pyrrolidone solution of spiny organic polymer to the slurry [2], and stir until homogeneous It can be obtained by It is not limited to the mixing of the respective components, the means of stirring the slurry [1] and the slurry [2]. For example, a self-revolving stirrer can be used.
［添加剤組成物］
本発明は、一実施態様において、正極合剤ペーストの調製に使用される添加剤組成物である。当該添加剤組成物は、有機ポリマーとNメチルピロリドンを含み、前記有機ポリマーがNメチルピロリドンに溶解した態様のものである。当該添加剤組成物における曳糸性有機ポリマーの含有量は、例えば、前記スラリー［２］との混合により、本発明の正極合剤ペーストを調製できるように設定されるが、添加剤組成物について高い曳糸性を示す観点から、好ましくは０．１質量％以上、より好ましくは０．５質量％以上であり、そして、有機ポリマーの溶解性の確保の観点から、好ましくは５質量％以下、より好ましくは３質量％以下である。本発明の添加剤組成物には、任意成分として、例えば増粘剤、補強材、酸化防止剤、電解液の分解を抑制する機能を有する添加剤等が含まれていてもよく、これらの成分は、公知のものを使用することができる。本添加剤組成物中の任意成分の量は、正極合剤ペーストの保存安定性の観点から、１０質量％以下が好ましく、より好ましくは、５質量％以下、更に好ましくは２質量％以下が好ましい。
[Additive composition]
The present invention, in one embodiment, is an additive composition used for preparation of a positive electrode mixture paste. The additive composition comprises an organic polymer and N methyl pyrrolidone, wherein the organic polymer is dissolved in N methyl pyrrolidone. The content of the spinnable organic polymer in the additive composition is set so that, for example, the positive electrode material mixture paste of the present invention can be prepared by mixing with the above-mentioned slurry [2]. From the viewpoint of exhibiting high spinnability, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and from the viewpoint of securing the solubility of the organic polymer, preferably 5% by mass or less More preferably, it is 3% by mass or less. The additive composition of the present invention may contain, as optional components, for example, a thickener, a reinforcing material, an antioxidant, an additive having a function of suppressing the decomposition of the electrolytic solution, etc., and these components. Any known one can be used. The amount of optional components in the additive composition is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less, from the viewpoint of storage stability of the positive electrode mixture paste .
［リチウムイオン電池用電極］
本発明は、一実施形態において、本発明の正極合剤ペーストを用いて形成された正極合剤層を含む、リチウムイオン電池用電極（以下、「本発明の電極」ともいう）に関する。本発明の電極は、本発明の正極合剤ペーストを用いること以外は公知の電極の製造方法により製造でき、例えば、本発明の正極合剤ペーストを集電体に塗布、乾燥した後、必要に応じてプレスして所定の寸法に加工することにより得られる。前記集電体には、従来から公知の集電体を用いることができる。
[Electrode for lithium ion battery]
The present invention relates, in one embodiment, to a lithium ion battery electrode (hereinafter also referred to as “the electrode of the present invention”) including a positive electrode mixture layer formed using the positive electrode mixture paste of the present invention. The electrode of the present invention can be produced by a known method for producing an electrode except that the positive electrode mixture paste of the present invention is used. For example, after the positive electrode mixture paste of the present invention is applied to a current collector and dried, It is obtained by processing according to a predetermined size by pressing accordingly. For the current collector, a conventionally known current collector can be used.
［リチウムイオン電池］
本発明は、一実施形態において、本発明の電極を含む、リチウムイオン電池（以下、「本発明の電池」ともいう）に関する。
[Lithium ion battery]
The present invention relates, in one embodiment, to a lithium ion battery (hereinafter also referred to as "the battery of the present invention") including the electrode of the present invention.
本発明の電池の形状としては、コイン型、円筒型、角型、及び積層型等のいずれの形状であってもよい。 The shape of the battery of the present invention may be any shape such as coin shape, cylindrical shape, square shape, and laminated shape.
本発明の電池は、本発明の電極を用いること以外は公知のリチウムイオン電池の製造方法により製造できる。リチウムイオン電池の製造方法の一実施形態としては、例えば、本発明の電極（正極）と負極を、セパレータを介して重ね合わせ、電池形状に捲回あるいは積層させて、電池容器あるいはラミネート容器に挿入し、該容器に電解液を注入して封口する方法が挙げられる。 The battery of the present invention can be manufactured by a known method for manufacturing a lithium ion battery except that the electrode of the present invention is used. As one embodiment of a method of manufacturing a lithium ion battery, for example, the electrode (positive electrode) of the present invention and a negative electrode are stacked via a separator, wound or stacked in a battery shape, and inserted into a battery container or a laminate container. And a method in which the container is filled with an electrolytic solution and sealed.
セパレータは、一実施形態において、正極と負極間の絶縁、さらには電解液を保持するなどの機能を持つ部材である。セパレータとしては、例えば、ポリエチレン、ポリプロピレン、あるいはそれら積層品等の薄い微多孔膜を用いることができる。 In one embodiment, the separator is a member having a function such as insulation between the positive electrode and the negative electrode, and further holding an electrolytic solution. As a separator, thin microporous membranes, such as polyethylene, a polypropylene, or those laminated products, can be used, for example.
電解液としては、通常、有機溶媒に電解質を溶解した溶液が用いられる。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等の環状カーボネート；ジエチルカーボネート、ジメチルカーボネート、メチルエチルカーボネート等の鎖状カーボネート；等が挙げられ、これらは単独又は２種以上を併用してもよい。電解質とは、有機溶媒に溶解して電気を伝導する働きを有するイオン性化合物を示す。電解質としては、例えば、ＬｉＣｌＯ4、ＬｉＰＦ6、ＬｉＢＦ4、ＬｉＣＦ3ＳＯ3、ＬｉＮ（ＣＦ3ＳＯ2）2、ＬｉＣＦ3ＣＯ2、ＬｉＣｌ、ＬｉＢｒ、ＬｉＳＣＮ等のリチウム塩を単独又は２種以上を併用してもよい。 As the electrolytic solution, a solution in which an electrolyte is dissolved in an organic solvent is usually used. Examples of the organic solvent include cyclic carbonates such as ethylene carbonate and propylene carbonate; linear carbonates such as diethyl carbonate, dimethyl carbonate and methyl ethyl carbonate; and the like, and these may be used alone or in combination of two or more . The electrolyte refers to an ionic compound having a function of dissolving in an organic solvent to conduct electricity. As the electrolyte, for example, lithium salts such as LiClO 4 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (CF 3 SO 2 ) 2 , LiCF 3 CO 2 , LiCl, LiBr, LiSCN, etc. alone or in combination of two or more You may use together.
本願は、さらに下記発明を開示する。
［１］ 正極活物質、導電材、バインダー、有機ポリマー、及びNメチルピロリドンを含有し、
前記有機ポリマーは、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペースト。
［２］ 前記正極合剤ペーストの全固形分量に対する、前記有機ポリマーの含有量が、好ましくは０．００１質量％以上、より好ましくは０．００５質量％以上であり、そして、好ましくは０．１質量％以下、より好ましくは０．０３質量％以下である、前記［１］に記載の正極合剤ペースト。
［３］ 前記有機ポリマーの重量平均分子量が、好ましくは２２０万以上、より好ましくは２５０万以上、更に好ましくは３００万以上であり、そして、好ましくは３０００万以下、より好ましくは２０００万以下、更に好ましくは１０００万以下である、前記［１］又は［２］に記載の正極合剤ペースト。
［４］ 前記曳糸性有機ポリマーが、好ましくはエチレンオキサイドに由来の構成単位を含むポリマーであり、より好ましくはポリエチレンオキサイドである、前記［１］から［３］のいずれかに記載の正極合剤ペースト。
［５］ 前記正極合剤ペーストにおける全固形分の濃度は、好ましくは５０質量％以上、より好ましくは６０質量％以上、更に好ましくは６５質量％以上、更により好ましくは７０質量％以上であり、そして、好ましくは９０質量％以下、より好ましくは８０質量％以下である、前記［１］から［４］のいずれかに記載の正極合剤ペースト。
［６］ 正極活物質が、リチウムニッケル含有複合酸化物である前記［１］から［５］のいずれかに記載の正極合剤ペースト。
［７］ 有機ポリマーとNメチルピロリドンとを含み、前記有機ポリマーがNメチルピロリドンに溶解しており、前記有機ポリマーは、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、添加剤組成物。
［８］ 前記［１］から［６］のいずれかに記載の正極合剤ペーストを用いて形成された正極合剤層を含む、リチウムイオン電池用電極。
［９］ 前記［１］から［６］のいずれかに記載の正極合剤ペーストを用いて形成された正極合剤層を含む、リチウムイオン電池。
［10］ 正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを混合する工程を含み、
前記曳糸性有機ポリマーは、その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの製造方法。
［11］ 正極活物質と、導電材と、バインダーと、Nメチルピロリドンとを混合する工程１と、
前記工程１で得られたスラリーと、前記［７］に記載の添加剤組成物とを混合する工程とを含む、リチウムイオン電池用正極合剤ペーストの製造方法。
［12］ 前記［７］に記載の添加剤組成物のリチウムイオン電池用正極合剤ペーストの調製への使用。
［13］ 前記［１］から［６］のいずれかに記載のリチウムイオン電池用正極合剤ペーストの、リチウムイオン電池用電極の形成のための使用。
［14］ 正極活物質と導電材とバインダーと水とを含むリチウムイオン電池用正極合剤ペーストの保存安定性の向上方法であって、
前記正極合剤ペーストの製造過程で、正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを混合物する工程を含み、
前記有機ポリマーは、その含有量が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの保存安定性向上方法。
The present application further discloses the following invention.
[1] containing a positive electrode active material, a conductive material, a binder, an organic polymer, and N methyl pyrrolidone,
The above-mentioned organic polymer is an organic polymer which exhibits spinnability in N methyl pyrrolidone solution whose concentration is 0.001 mass% or more and 3 mass% or less and the liquid temperature is 25 ° C., positive electrode mixture for lithium ion battery paste.
[2] The content of the organic polymer is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, based on the total solid content of the positive electrode mixture paste, and preferably 0.1 The positive electrode mixture paste according to the above [1], which is not more than mass%, more preferably not more than 0.03 mass%.
[3] The weight average molecular weight of the organic polymer is preferably 2.2 million or more, more preferably 2.5 million or more, still more preferably 3 million or more, and preferably 30 million or less, more preferably 20 million or less, furthermore The positive electrode mixture paste according to the above [1] or [2], which is preferably 10,000,000 or less.
[4] The positive electrode composite according to any one of the above [1] to [3], wherein the spinnable organic polymer is preferably a polymer containing a structural unit derived from ethylene oxide, more preferably polyethylene oxide Agent paste.
[5] The concentration of total solids in the positive electrode mixture paste is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and still more preferably 70% by mass or more. The positive electrode mixture paste according to any one of the above [1] to [4], which is preferably 90% by mass or less, more preferably 80% by mass or less.
[6] The positive electrode mixture paste according to any one of the above [1] to [5], wherein the positive electrode active material is a lithium nickel-containing composite oxide.
[7] The organic polymer is dissolved in N-methyl pyrrolidone, and the organic polymer has a concentration of 0.001% to 3% by mass and a liquid temperature of 25%. An additive composition which is an organic polymer exhibiting spinnability in an N-methylpyrrolidone solution at 0 ° C.
[8] An electrode for a lithium ion battery, comprising a positive electrode mixture layer formed using the positive electrode mixture paste according to any one of the above [1] to [6].
[9] A lithium ion battery including a positive electrode mixture layer formed using the positive electrode mixture paste according to any one of the above [1] to [6].
[10] including the step of mixing the positive electrode active material, the conductive material, the binder, the organic polymer, and N-methylpyrrolidone,
The above spinnable organic polymer is an organic polymer showing spinnability in an N-methylpyrrolidone solution having a concentration of 0.001% by mass to 3% by mass and a liquid temperature of 25 ° C. The manufacturing method of positive mix paste.
[11] Step 1 of mixing the positive electrode active material, the conductive material, the binder, and N-methylpyrrolidone
The manufacturing method of the positive mix paste for lithium ion batteries including the process of mixing the slurry obtained at the said process 1, and the additive composition as described in said [7].
[12] Use of the additive composition according to [7] for the preparation of a positive electrode material mixture paste for lithium ion batteries.
[13] Use of the positive electrode material mixture paste for a lithium ion battery according to any one of the above [1] to [6] for the formation of an electrode for a lithium ion battery.
[14] A method for improving the storage stability of a positive electrode material mixture paste for lithium ion batteries, comprising a positive electrode active material, a conductive material, a binder, and water,
Including the step of mixing the positive electrode active material, the conductive material, the binder, the organic polymer, and N-methylpyrrolidone in the production process of the positive electrode mixture paste,
The above-mentioned organic polymer is an organic polymer which exhibits spinnability in an N-methylpyrrolidone solution having a content of 0.001% by mass to 3% by mass and a liquid temperature of 25 ° C. Method for improving storage stability of
以下、実施例により本開示を説明するが、本開示はこれに限定されるものではない。 Hereinafter, the present disclosure will be described by way of examples, but the present disclosure is not limited thereto.
〔重量平均分子量の定義〕
有機ポリマーの重量平均分子量は、下記測定条件のゲル・パーミエーション・クロマトグラフ（ＧＰＣ）測定により決定できる。標準サンプルにはポリエチレンオキサイド（ＰＥＯ）を使用し、ＰＥＯ換算の重量平均分子量を用いる。
〔ＧＰＣ法測定条件〕
カラムとしてＰＷ／ＧＭＰＷＸＬ／ＧＭＰＷＸＬ（東ソー（株）製）、溶離液として０．２Ｍリン酸バッファー（ＫＨ2ＰＯ4、Ｎａ2ＨＰＯ4、ｐＨ＝７）／ＣＨ3ＣＮ＝９／１（重量比）を用い、カラム温度は４０℃、流速は１．０ｍＬ／ｍｉｎ、サンプル濃度は１〜１００μｇ／ｍＬとした。検出器は、ＲＡＬＬＳ（９０°光散乱解析計）を用いた。尚、ＲＩＤ（示差屈折計）を用いても重量平均分子量の概算値を見積もることができる。ＲＩＤを用いたＧＰＣ分析は、例えば、カラム：ＧＭＰＷＸＬ＋ＧＭＰＷＸＬ、溶離液：０．２Ｍリン酸バッファー／ＣＨ3ＣＮ＝９／１（重量比）、カラム温度：４０℃、流速：０．５ｍＬ／ｍｉｎ、濃度：０．０５ｍｇ／ｍＬとして測定する。
[Definition of weight average molecular weight]
The weight average molecular weight of the organic polymer can be determined by gel permeation chromatography (GPC) measurement under the following measurement conditions. Polyethylene oxide (PEO) is used as a standard sample, and the weight average molecular weight in terms of PEO is used.
[GPC method measurement conditions]
As a column, PW / GMPWXL / GMPWXL (manufactured by Tosoh Corp.), as an eluent, 0.2 M phosphate buffer (KH 2 PO 4 , Na 2 HPO 4 , pH = 7) / CH 3 CN = 9/1 (weight ratio) The column temperature was 40 ° C., the flow rate was 1.0 mL / min, and the sample concentration was 1 to 100 μg / mL. The detector used was RALLS (90 ° light scattering analyzer). The approximate value of the weight average molecular weight can also be estimated using RID (differential refractometer). GPC analysis using RID is, for example, column: GMPWXL + GMPWXL, eluent: 0.2 M phosphate buffer / CH 3 CN = 9/1 (weight ratio), column temperature: 40 ° C., flow rate: 0.5 mL / min, Concentration: Measure as 0.05 mg / mL.
［正極合剤ペースト及び各成分の固形分濃度］
正極合剤ペーストの全固形分濃度、及び各成分の固形分濃度は、１５０℃で２４時間乾燥し重量減量を測定することにより算出した。
[Solid content concentration of positive electrode mixture paste and each component]
The total solid content concentration of the positive electrode mixture paste and the solid content concentration of each component were calculated by drying at 150 ° C. for 24 hours and measuring the weight loss.
［正極合剤ペーストの作製］
（１）実施例１の正極合剤ペースト
導電材（アセチレンブラック、デンカ社製、「ＨＳ-１００」）０．６５ｇ、バインダー（ポリフッ化ビニリデンのＮメチルピロリドン溶液（固形分１２質量％）、クレハ社製、「KFポリマーL＃1120」）５．４２ｇを混合して、スラリー［１］を調製し、次いで、当該スラリー［１］に正極活物質（ＮＣＡ、日本化学産業社製 「NC-02」）を１５ｇ、及び溶剤（Ｎメチルピロリドン、和光純薬製）４．３１ｇを入れて混合して、スラリー［２］を調製した。スラリー［２］における固形分は、正極活物質、導電材、及びバインダーであり、非水系正極合剤ペースト中の全固形分濃度は６４．２質量％であり、正極活物質、導電材、バインダーの質量比率は９２：４：４（固形分換算）である。
次に、スラリー［２］へ、ポリエチレンオキサイド（重量平均分子量：４００万、和光純薬社製）の１重量％Nメチルピロリドン溶液を、０．２６ｇ添加し混合することで、実施例１の正極合剤ペーストを調製した。正極合剤ペーストの全固形分濃度は、６３．６質量％であり、正極活物質、導電材、バインダー、ポリエチレンオキサイドの質量比率は、９２：４：４：０．０１６（固形分換算）である。
[Preparation of positive electrode mixture paste]
(1) The positive electrode mixture paste of Example 1 0.65 g of a conductive material (acetylene black, manufactured by Denka, "HS-100"), a binder (N methyl pyrrolidone solution of polyvinylidene fluoride (solid content 12 mass%), Kureha Co., Ltd., “KF polymer L # 1120” 5.42 g is mixed to prepare a slurry [1], and then, the slurry [1] is prepared by mixing positive electrode active material (NCA, manufactured by Nippon Chemical Industrial Co., Ltd. “NC-02 15 g) and 4.31 g of a solvent (N methyl pyrrolidone, manufactured by Wako Pure Chemical Industries, Ltd.) were added and mixed to prepare a slurry [2]. The solid content in the slurry [2] is a positive electrode active material, a conductive material, and a binder, and the total solid concentration in the non-aqueous positive electrode mixture paste is 64.2% by mass, and the positive electrode active material, the conductive material, and the binder The mass ratio of (F) is 92: 4: 4 (solid content conversion).
Next, the positive electrode of Example 1 was added by adding 0.26 g of a 1 wt% N methylpyrrolidone solution of polyethylene oxide (weight average molecular weight: 4,000,000, manufactured by Wako Pure Chemical Industries, Ltd.) to slurry [2]. A mixture paste was prepared. The total solid concentration of the positive electrode mixture paste is 63.6% by mass, and the mass ratio of the positive electrode active material, the conductive material, the binder, and the polyethylene oxide is 92: 4: 4: 0.016 (in terms of solid content). is there.
（２）実施例２の正極合剤ペースト（実施例１の高濃度品）
実施例１と同様の手法でスラリー［１］を調製し、次いで、当該スラリー［１］に正極活物質（ＮＣＡ、日本化学産業社製 「NC-02」）を１５ｇ、及びポリエチレンオキサイド（重量平均分子量：４００万、和光純薬社製）の１重量％Nメチルピロリドン溶液を、０．２１ｇ添加し混合することで、実施例２の正極合剤ペーストを調製した。正極合剤ペーストの全固形分濃度は、７６．６質量％であり、正極活物質、導電材、バインダー、ポリエチレンオキサイドの質量比率は、９２：４：４：０．０１３（固形分換算）である。
(2) Cathode mix paste of Example 2 (high concentration product of Example 1)
A slurry [1] is prepared in the same manner as in Example 1, and then 15 g of a positive electrode active material (NCA, “NC-02” manufactured by Nippon Chemical Industrial Co., Ltd.) and the polyethylene oxide (weight average) are prepared in the slurry [1]. A positive electrode mixture paste of Example 2 was prepared by adding and mixing 0.21 g of a 1 wt% N methyl pyrrolidone solution of molecular weight: 4,000,000, manufactured by Wako Pure Chemical Industries, Ltd.). The total solid concentration of the positive electrode mixture paste is 76.6% by mass, and the mass ratio of the positive electrode active material, the conductive material, the binder, and the polyethylene oxide is 92: 4: 4: 0.013 (in terms of solid content). is there.
（３）比較例１の正極合剤ペースト
実施例１で調整したスラリー［２］を、比較例１の正極合剤ペーストとした。
(3) Positive Electrode Mixture Paste of Comparative Example 1 The slurry [2] prepared in Example 1 was used as the positive electrode mixture paste of Comparative Example 1.
（４）比較例２の正極合剤ペースト
実施例１と同様の方法でスラリー［２］を調製し、次にスラリー［２］へ、ポリアクリル酸（重量平均分子量：４００万、アルドリッチ社製）の１重量％Nメチルピロリドン溶液を、０．２６ｇ添加し混合することで、比較例２の正極合剤ペーストを調製した。正極合剤ペーストの全固形分濃度は、６３．６質量％であり、正極活物質、導電材、バインダー、ポリアクリル酸の質量比率は、９２：４：４：０．０１６（固形分換算）である。
(4) Cathode mix paste of Comparative Example 2 A slurry [2] is prepared by the same method as in Example 1, and then, to slurry [2], polyacrylic acid (weight average molecular weight: 4,000,000, manufactured by Aldrich) The positive electrode material mixture paste of Comparative Example 2 was prepared by adding and mixing 0.26 g of a 1% by weight N methyl pyrrolidone solution. The total solid concentration of the positive electrode mixture paste is 63.6% by mass, and the mass ratio of the positive electrode active material, the conductive material, the binder, and the polyacrylic acid is 92: 4: 4: 0.016 (in terms of solid content) It is.
（５）比較例３の正極合剤ペースト
実施例１と同様の手法でスラリー［１］を調製し、次いで、当該スラリー［１］に正極活物質（ＮＣＡ、日本化学産業社製 「NC-02」）を１５ｇ、及びポリアクリル酸（重量平均分子量：４００万、アルドリッチ社製）の１重量％Nメチルピロリドン溶液を、０．２１ｇ添加し混合したが、湿った粉体状のままで、ペーストにならなかった。
(5) Positive electrode mixture paste of Comparative Example 3 A slurry [1] is prepared by the same method as in Example 1, and then, the slurry [1] is prepared by using a positive electrode active material (NCA, manufactured by Nippon Chemical Industrial Co., Ltd. "NC-02 And 0.21 g of 1% by weight N methyl pyrrolidone solution of polyacrylic acid (weight average molecular weight: 4,000,000, manufactured by Aldrich) were added and mixed, but the paste was still wet powdery. It did not become.
［曳糸性判定］
実施例１〜３、比較例２〜３の正極合剤ペーストの調製に用いた有機ポリマーを、各々、Nメチルピロリドンに溶解させ、それぞれ１質量％の有機ポリマーのNメチルピロリドン溶液を調製した。これらの有機ポリマーのNメチルピロリドン溶液について本文記載の曳糸性判定法に基づき、曳糸性の有無の判定を行った結果を表１に示す。
[Tip thread determination]
The organic polymers used to prepare the positive electrode material mixture pastes of Examples 1 to 3 and Comparative Examples 2 to 3 were dissolved in N methyl pyrrolidone, respectively, to prepare 1 mass% N methyl pyrrolidone solutions of organic polymers. Table 1 shows the results of determination of the presence or absence of spinnability based on the spinnability determination method described in the text for N methyl pyrrolidone solutions of these organic polymers.
１．正極合剤ペーストの保存安定性試験
実施例１〜２、比較例１〜３の正極合剤ペーストを、各々サンプル瓶に入れて密封し、室温で３日間静置した。３日後の状態を観察し、その結果を下記基準により評価して、その結果を表２に示している。
Ａ：ゲル化せずに良好なペーストの状態を保っている。
Ｂ：増粘して塗工が困難である。
Ｃ：ゲル化又は固化して塗工が非常に困難である。
1. Storage stability test of positive electrode mixture paste The positive electrode mixture pastes of Examples 1 and 2 and Comparative Examples 1 to 3 were each put in a sample bottle, sealed, and allowed to stand at room temperature for 3 days. The condition after 3 days was observed, the results were evaluated according to the following criteria, and the results are shown in Table 2.
A: A good paste state is maintained without gelation.
B: Thickened and coating is difficult.
C: It is gelled or solidified and coating is very difficult.
２．電極（正極）及び電池の作製
厚さ２０μｍのアルミ箔上に、正極容量密度が１．０〜１．２ｍＡｈ/ｃｍ2となるように、正極合剤ペーストを塗工し、真空乾燥器を用いて１００℃で１２時間乾燥し、集電体上に正極合剤層が形成された電極材料を作製した。この正極材料を直径１３ｍｍに打ち抜きプレスして電極（正極）を得た。当該正極上に、直径１９ｍｍのセパレータ、直径１５ｍｍ厚さ０．５のコイン状金属リチウムを配置して、２０３２型コインセルを作製した。電解液には、１Ｍ ＬｉＰＦ6 ＥＣ/ＤＥＣ（体積比）＝３/７を用いた。正極合剤層の形成には、実施例１〜３、比較例１〜３の正極合剤ペーストとして、各々、調製直後の正極合剤ペースト、及び２５℃の雰囲気下ポリエチレン製容器内で１週間保存後の正極合剤ペーストを用いた。
2. Preparation of Electrode (Positive Electrode) and Battery A positive electrode material mixture paste is coated on a 20 μm thick aluminum foil so that the positive electrode capacity density is 1.0 to 1.2 mAh / cm 2, and a vacuum drier is used. It dried at 100 degreeC for 12 hours, and produced the electrode material in which the positive mix layer was formed on the collector. The positive electrode material was punched and pressed to a diameter of 13 mm to obtain an electrode (positive electrode). On the positive electrode, a separator of 19 mm in diameter and coin-like metal lithium of 15 mm in diameter and 0.5 in thickness were disposed to prepare a 2032 type coin cell. As an electrolytic solution, 1 M LiPF 6 EC / DEC (volume ratio) = 3/7 was used. For formation of the positive electrode mixture layer, as the positive electrode mixture paste of Examples 1 to 3 and Comparative Examples 1 to 3, the positive electrode mixture paste immediately after preparation and one week in a polyethylene container under an atmosphere of 25 ° C. The positive electrode mixture paste after storage was used.
３．充放電試験
コインセルを用いて、次に記載する条件で３サイクル充放電試験を行い、３サイクル目の放電容量を表２に示した。正極合剤層の形成に、調製直後の正極合剤ペーストを用いたコインセルの放電容量は、表２中の「初期放電容量」に示した。
［充放電条件］
３０℃、０．１ＣＡ、充電４．３Ｖ ＣＣ/ＣＶ １/１０Ｃカットオフ
放電ＣＣ２．０Ｖカットオフ
3. Charge / Discharge Test A 3-cycle charge / discharge test was conducted under the conditions described below using a coin cell, and the discharge capacity in the third cycle is shown in Table 2. The discharge capacity of the coin cell using the positive electrode mixture paste immediately after preparation for forming the positive electrode mixture layer is shown in “Initial discharge capacity” in Table 2.
[Charge and discharge conditions]
30 ° C, 0.1 CA, charging 4.3 V CC / CV 1/10 C cutoff discharge CC 2.0 V cutoff
表２に示されるように、曳糸性有機ポリマーを含む実施例１〜２の正極合剤ペーストの保存安定性は、曳糸性の無い有機ポリマーを含む比較例１〜３の正極合剤ペーストと比較して、良好であった。一方、曳糸性の無い有機ポリマーを含む比較例３の正極合剤は、固形分濃度が７６．６％と高濃度であるためペースト状にならず集電体への塗工自体が困難であった。しかしながら、実施例２の曳糸性有機ポリマーを含む正極合剤は、ペースト状になり、集電体への塗工が可能であった。このことから、曳糸性有機ポリマーを用いると、固形分の濃度が高い正極合剤ペーストを調製可能であることがわかる。 As shown in Table 2, the storage stability of the positive electrode mixture paste of Examples 1 and 2 containing the spinnable organic polymer was higher than that of the positive electrode mixture paste of Comparative Examples 1 to 3 containing the organic polymer having no spinnability. It was good compared with. On the other hand, the positive electrode mixture of Comparative Example 3 containing an organic polymer without spinnability has a high solid content concentration of 76.6% and does not become paste-like and coating on the current collector itself is difficult. there were. However, the positive electrode mixture containing the spinnable organic polymer of Example 2 was in the form of a paste and could be applied to the current collector. From this, it is understood that when using a spinnable organic polymer, it is possible to prepare a positive electrode mixture paste having a high concentration of solid content.
本発明は、簡単な方法により、ペーストにおける固形分濃度を上げることができ、且つ、保存安定性が良好であるので、リチウムイオン電池の製造におけるコストダウンに寄与し得る。 The present invention can contribute to cost reduction in the manufacture of a lithium ion battery because the solid concentration in the paste can be increased by a simple method and the storage stability is good.
Claims (10)
前記有機ポリマーは、
その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペースト。 Containing a positive electrode active material, a conductive material, a binder, an organic polymer, and N-methylpyrrolidone,
The organic polymer is
The positive mix paste for lithium ion batteries which is an organic polymer which shows spinnability in the N methyl pyrrolidone solution whose density | concentration is 0.001 mass% or more and 3 mass% or less, and whose liquid temperature is 25 degreeC.
前記有機ポリマーは、
その濃度が０．００１質量％以上３質量％以下であり液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、添加剤組成物。 An organic polymer and N methyl pyrrolidone, wherein the organic polymer is dissolved in N methyl pyrrolidone,
The organic polymer is
The additive composition which is an organic polymer which shows spinnability in the N methyl pyrrolidone solution whose density | concentration is 0.001 mass% or more and 3 mass% or less, and whose liquid temperature is 25 degreeC.
前記有機ポリマーは、
その濃度が０．００１質量％以上３質量％以下であり、液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの製造方法。 Mixing the positive electrode active material, the conductive material, the binder, the organic polymer, and N-methylpyrrolidone,
The organic polymer is
A method for producing a positive electrode mixture paste for lithium ion battery, which is an organic polymer exhibiting spinnability in an N-methylpyrrolidone solution having a concentration of 0.001% by mass to 3% by mass and a solution temperature of 25 ° C. .
前記正極合剤ペーストの製造過程で、正極活物質と、導電材と、バインダーと、有機ポリマーと、Nメチルピロリドンとを混合する工程を含み、
前記有機ポリマーは、
その濃度が０．００１質量％以上３質量％以下であり、液温が２５℃のNメチルピロリドン溶液中で、曳糸性を示す有機ポリマーである、リチウムイオン電池用正極合剤ペーストの保存安定性向上方法。 A method for improving the storage stability of a positive electrode material mixture paste for a lithium ion battery, comprising a positive electrode active material, a conductive material, a binder and water,
Including the step of mixing a positive electrode active material, a conductive material, a binder, an organic polymer, and N-methylpyrrolidone in the production process of the positive electrode mixture paste,
The organic polymer is
Storage stability of positive electrode material mixture paste for lithium ion battery, which is an organic polymer exhibiting spinnability in N methyl pyrrolidone solution having a concentration of 0.001% by mass to 3% by mass and a solution temperature of 25 ° C. How to improve.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017254068A JP7057666B2 (en) | 2017-12-28 | 2017-12-28 | Positive electrode mixture paste for lithium-ion batteries and its manufacturing method |
| PCT/JP2018/048589 WO2019132036A1 (en) | 2017-12-28 | 2018-12-28 | Positive electrode mixture paste for lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017254068A JP7057666B2 (en) | 2017-12-28 | 2017-12-28 | Positive electrode mixture paste for lithium-ion batteries and its manufacturing method |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2019121471A true JP2019121471A (en) | 2019-07-22 |
| JP2019121471A5 JP2019121471A5 (en) | 2020-11-26 |
| JP7057666B2 JP7057666B2 (en) | 2022-04-20 |
Family
ID=67306463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2017254068A Active JP7057666B2 (en) | 2017-12-28 | 2017-12-28 | Positive electrode mixture paste for lithium-ion batteries and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7057666B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114335539A (en) * | 2021-12-27 | 2022-04-12 | 苏州宇量电池有限公司 | Method for preventing gel formation of lithium ion battery anode slurry |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005268206A (en) * | 2004-02-16 | 2005-09-29 | Sony Corp | Positive electrode mixture, nonaqueous electrolyte secondary battery and its manufacturing method |
| JP2005346946A (en) * | 2004-05-31 | 2005-12-15 | Sanyo Electric Co Ltd | Manufacturing method of hydrogen storage alloy electrode |
| WO2011062232A1 (en) * | 2009-11-18 | 2011-05-26 | 三井化学株式会社 | Aqueous paste for electrochemical cell, electrode plate for electrochemical cell obtained by application of the aqueous paste, and battery comprising the electrode plate |
| WO2014192238A1 (en) * | 2013-05-29 | 2014-12-04 | 日本ゼオン株式会社 | Slurry composition for lithium-ion secondary battery positive electrode, production method for lithium-ion secondary battery positive electrode, lithium-ion secondary battery positive electrode, and lithium-ion secondary battery |
| JP2015513206A (en) * | 2012-04-13 | 2015-04-30 | アーケマ・インコーポレイテッド | Batteries made from organic sulfur species |
| JP2016076493A (en) * | 2013-06-20 | 2016-05-12 | Jsr株式会社 | Composition for power storage device, slurry for power storage device, power storage device electrode and manufacturing method thereof, protection film and manufacturing method thereof, and power storage device |
-
2017
- 2017-12-28 JP JP2017254068A patent/JP7057666B2/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005268206A (en) * | 2004-02-16 | 2005-09-29 | Sony Corp | Positive electrode mixture, nonaqueous electrolyte secondary battery and its manufacturing method |
| JP2005346946A (en) * | 2004-05-31 | 2005-12-15 | Sanyo Electric Co Ltd | Manufacturing method of hydrogen storage alloy electrode |
| WO2011062232A1 (en) * | 2009-11-18 | 2011-05-26 | 三井化学株式会社 | Aqueous paste for electrochemical cell, electrode plate for electrochemical cell obtained by application of the aqueous paste, and battery comprising the electrode plate |
| JP2015513206A (en) * | 2012-04-13 | 2015-04-30 | アーケマ・インコーポレイテッド | Batteries made from organic sulfur species |
| WO2014192238A1 (en) * | 2013-05-29 | 2014-12-04 | 日本ゼオン株式会社 | Slurry composition for lithium-ion secondary battery positive electrode, production method for lithium-ion secondary battery positive electrode, lithium-ion secondary battery positive electrode, and lithium-ion secondary battery |
| JP2016076493A (en) * | 2013-06-20 | 2016-05-12 | Jsr株式会社 | Composition for power storage device, slurry for power storage device, power storage device electrode and manufacturing method thereof, protection film and manufacturing method thereof, and power storage device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114335539A (en) * | 2021-12-27 | 2022-04-12 | 苏州宇量电池有限公司 | Method for preventing gel formation of lithium ion battery anode slurry |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7057666B2 (en) | 2022-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20140087250A1 (en) | Binder for a secondary battery cell | |
| US10752733B2 (en) | Binder for electrochemical element | |
| CN110383557A (en) | Nonaqueous electrolytic solution and nonaqueous electrolytic solution secondary battery | |
| CN111213268B (en) | Binder, and electrode and lithium secondary battery comprising same | |
| JPWO2014141552A1 (en) | Method for producing paste for negative electrode production, method for producing negative electrode for lithium ion secondary battery, negative electrode for lithium ion secondary battery and lithium ion secondary battery | |
| CN109997262A (en) | binder for electrochemical element | |
| KR102049679B1 (en) | The lithium ion secondary battery provided with the positive electrode for lithium ion secondary batteries obtained using the slurry for positive electrodes of a lithium ion secondary battery, the slurry for positive electrodes of a lithium ion secondary battery, and its manufacturing method, and the positive electrode for lithium ion secondary batteries, and its manufacturing method | |
| JP7053337B2 (en) | Electrodes for non-aqueous electrolyte secondary batteries | |
| US9287586B1 (en) | Electrolyte solutions for high energy cathode materials and methods for use | |
| JP7118138B2 (en) | Lithium-sulfur battery separator and lithium-sulfur battery including the same | |
| CN110679010B (en) | Lithium-sulfur battery | |
| JP7057666B2 (en) | Positive electrode mixture paste for lithium-ion batteries and its manufacturing method | |
| JP2016134218A (en) | Lithium ion secondary battery | |
| JP5271751B2 (en) | Lithium ion secondary battery | |
| US11251419B2 (en) | Lithium ion battery having improved thermal stability | |
| JP2008283161A (en) | Electrochemical capacitor and electrolyte therefor | |
| JP6931491B2 (en) | How to manufacture electrodes for electrochemical power storage devices | |
| KR102255530B1 (en) | Preparing method for electrode for lithium secondary battery, electrode for lithium secondary battery, and lithium secondary battery comprising the same | |
| JP2019215961A (en) | Non-aqueous electrolyte for secondary battery including specific additive and secondary battery using the same | |
| WO2020204058A1 (en) | Binder for electrochemical elements | |
| JP2018125219A (en) | Electrolyte solution for lithium ion secondary battery | |
| JP7057665B2 (en) | Positive electrode mixture paste for lithium-ion batteries and its manufacturing method | |
| JP2022002188A (en) | Separator for lithium ion battery | |
| WO2019065883A1 (en) | Binder for electrochemical elements | |
| WO2019132036A1 (en) | Positive electrode mixture paste for lithium ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20200910 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20201019 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20210805 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20211001 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20211221 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20220113 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20220405 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20220408 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 7057666 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |