TWI330902B - - Google Patents

Description

1330902 (1) Field of the Invention [Technical Field] The present invention relates to a non-aqueous electrolyte battery, particularly an electrode adhesive for use in a lithium battery, an electrode depolarizing mixture, an electrode thereof, and a use thereof Non-aqueous electrolyte battery. [Prior Art] In recent years, the development of electronic technology has been amazing, and various machines can be compact and lightweight. In combination with the small size and light weight of this electronic device, the battery for power supply is very small and lightweight. A battery that can obtain more energy as a small volume and weight. It is a non-aqueous secondary battery using lithium. It can be used as a power source for small-sized electronic devices for mobile phones, personal computers, video recorders, etc. The structural system is used in the state in which the active material and the conductive agent hold the current collector with the binder, the positive electrode active material is a lithium composite oxide, the negative electrode active material is a carbon element material, and the adhesive φφ mixture which is combined with the active materials is mainly used. A vinylidene fluoride polymer. Japanese Laid-Open Patent Publication No. Hei 11-329443 is exemplified by a mixture of a vinylidene-based polymer having no functional group and a cellulose-based polymer, and its bonding property is insufficient. The safety is not fully considered. However, 'the market demand for small and light weight of the machine and the growth of the battery life' requires a higher capacity of the lithium battery. Compared with the conventional product, the battery is internally overloaded with a large amount of current due to the increased capacity of the internal electrode. The flow to the local 'causes the temperature rise of the battery, causing the dangerous state of the battery-5-(2) 1330902 rupture, fuming, igniting, etc., and increasing the risk [invention] [disclosure of the invention] The problem is to provide an electrode binder composition for a non-electrolyte battery that maintains the high capacity required for a non-hydrolyzate battery and improves the safety of the performance and internal short-circuit, and uses the electrode thereof.

And non-aqueous electrolyte batteries. In order to solve the above-mentioned problems, the present invention provides a non-aqueous electrolysis using a positive electrode and/or a negative electrode binder as a nonaqueous electrolyte battery having a positive electrode and a negative electrode capable of absorbing and releasing a clock. A binder composition for a liquid battery electrode. Further, another aspect of the present invention is to provide an electrode depolarization mixture containing the binder composition and the electrode active material, an electrode having the electrode depolarization mixture layer on the current collector, and at least one of a positive electrode and a negative electrode. A non-aqueous electrolyte battery containing the electrode. The reason for improving the above-mentioned binder composition, maintaining the high capacity necessary for the non-aqueous electrolyte battery, and the safety of the performance and the safety of the internal short-circuit is not clear, and may be considered as a polymer containing a functional group of vinylidene fluoride. The carboxyl group or the epoxy group and the hydroxyl group and the carbonyl group of the polar polymer, the binder formed on the surface of the collector or the surface of the electrode active material and the hydrogen element are combined to improve the bonding property, and the surface of the electrode active material forms a non-aqueous electrolysis. The penetration of the liquid and the selection of the lithium ion permeable membrane suppress the formation of the lithium compound by the reaction of the electrolyte with the lithium ion during the charge and discharge of the surface of the electrode active material, and it is preferable to charge the -6-(4) 1330902 polymer. These functional group-containing vinylidene fluoride-based polymers can be obtained by a known suspension polymerization, emulsion polymerization, solution polymerization or the like. Further, the method of introducing a functional group may be carried out by heating a defluorinated acid with a base of a vinylidene fluoride-based polymer, followed by treatment with an organic acid or an oxidizing agent to obtain a functional group polymer.

The molecular weight of the functionally-containing vinylidene fluoride-based polymer is disclosed in Japanese Laid-Open Patent Publication No. Hei 9-2 8 902 3, the standard of which is a logarithmic viscosity (resin 4 g of L, Ν-trimethylformamide) The dissolved solution has a logarithmic concentration at 30 ° C of 0.8 to 20 dl / g, preferably 1.0 to 20 dl / g, more preferably 1.0 to 15 dl / g, and more preferably 1.2 to 15 dl / g. range. When the logarithmic reduced viscosity of the vinylidene fluoride-based polymer is less than the above range, the viscosity of the electrode depolarizing mixture is too low to coat, and when it exceeds the above range, it is difficult to dissolve the organic solvent. The polar polymer used in the present invention contains a polymer having a hydroxyl group and a polymer having a carbonyl group. The polymer having a hydroxyl group includes, for example, an ethylene vinyl alcohol copolymer, a cellulose polymer, or a vinyl phenol polymer. Further, the polymer having a carbonyl group is a polyacrylic polymer, and specifically contains, for example, polyacrylic acid, a polyacrylic acid crosslinked polymer, and the like. Polyvinylpyrrolidone is also suitable for polar polymers. If necessary, a functional polymer based vinylidene fluoride-based polymer, a polar polymer having a hydroxyl group or a carbonyl group, may be added as a separate polymer of vinylidene fluoride's vinylidene fluoride and vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene And a copolymer of a monomer copolymerizable with vinylidene fluoride such as tetrafluoroethylene or hexafluoropropylene. The mixing ratio of the functional group-containing vinylidene fluoride copolymer to the polar polymer of the present invention, the functional group-containing vinylidene fluoride copolymer is 1 〇 to 99% by weight -8-(6) 1330902 to be used in an amount of 0.1 to 30 parts by weight. It is particularly preferable to use a ratio of 0.5 to 20 parts by weight. Χ When the binder composition is dissolved in an organic solvent in advance, the solvent is used alone or in combination of two or more kinds, and the binder composition is 0 to] to 30 parts by weight, particularly 1 to 20 parts by weight, per 100 parts by weight of the solvent. The ratio is ideal.

For the mixing device of the depolarizing mixture composed of the binder composition, the powder electrode material, and the organic solvent, a homomixer or a multi-axis satellite type dispersion mixing kneader or emulsifier can be used. These are not particularly limited. The depolarized mixture slurry prepared by the above method uniformly disperses and mixes the mixed powder electrode material and the binder composition, has good coating properties, and coats the collector. The method of coating is well known, and it is also desirable to use a knife method. The depolarization mixture on the current collector is a 50~1 70 art drying solvent. The electrode structure for the nonaqueous secondary battery is formed by a hot pressing step as necessary. The binder composition and the electrode depolarization mixture of the present invention. It can be used at least for the formation of the positive electrode and the negative electrode, and is used for one of the negative electrodes as the ideal φφ. This is a binder which constitutes a powder electrode material of a negative electrode which requires a high bonding property, and the binder composition of the present invention is particularly suitable for use. [Embodiment] Hereinafter, the present invention will be more specifically described by way of Examples and Comparative Examples. (Production of functional group-containing vinylidene fluoride copolymer Α) The pressure device with a volume of 2L was charged with 1075 g of ion-exchanged water, methyl cellulose 〇.4 g, vinylidene fluoride monomer (VDF) 398 g, maleic acid monomethyl Base ester-10-(7)(7)1330902 (MMM) 2 g, isopropyl peroxydicarbonate 2.5 g, ethyl acetate 5 g, suspension polymerization at 28 ° C for 27 hours. After the end of the polymerization, the polymer slurry is dehydrated, washed with water, dehydrated, and dried at 80 ° C for 20 hours to obtain a functional group of the present invention having a yield of 89% and a logarithmic viscosity of 1.1 dl/g. Vinylidene-based polymer A. (Production of functional group-containing vinylidene fluoride-based polymer B) The pressurizer containing 2 L of internal volume was charged with ion-exchanged water of 10.7g, methylcellulose 〇.4g, vinylidene fluoride monomer (VDF) of 400g, two 3 g of methyl glycidyl methacrylate (2M-GMA), 2.5 g of isopropyl peroxydicarbonate and 5 g of ethyl acetate were subjected to suspension polymerization for 24 hours at 28 t. After the end of the polymerization, the polymer slurry was dehydrated, washed with water, dried, and dried at 80 ° C for 20 hours to obtain a functional vinylidene fluoride-containing polymer of the present invention having a yield of 90% and a logarithmic viscosity of 2.4 dl/g. B. (Production of vinylidene fluoride-based polymer C) ·_ Pressurizer with an internal volume of 2L was charged with ion-exchanged water 1 0 7 5 g, methylcellulose 〇.4g, vinylidene fluoride monomer (VDF) 400g, isopropyl After the base of the oxidized dicarbonate (2.5 g, ethyl acetate 5 g), the suspension polymerization was carried out at 26 ° C for 20 hours, the polymer slurry was dehydrated, washed with water, dehydrated, and dried at 80 ° C for 20 hours to obtain a yield. 9 1 %, a vinylidene fluoride-based polymer C (polyvinylidene fluoride) of the present invention having a logarithmic viscosity of 1.1 dl/g. -11 - (8) (8) 1330902 <Examples> (Production of positive electrode) 94 parts by weight of lithium succinate ("SELSEED C-5", manufactured by Nippon Chemical Industry Co., Ltd.), part by weight of vinylidene fluoride polymer C3, To 3 parts by weight of carbon black, 43 parts by weight of N-methyl-2-pyrrolidone (NMP) was added, and a polar depolarization mixture for a positive electrode was mixed and prepared. The obtained electrode was depolarized on an aluminum foil of 10 V m, uniformly coated to obtain a film thickness of about 100/zm after drying, and dried at 130 ° C for 25 minutes to obtain a positive electrode structure (active material mass: 29 1 g/m2). (Production of Negative Electrode) Ethylene vinyl alcohol copolymer (EVOH, "K卩-G 1 5 6 B", manufactured by KURARE Co., Ltd., with an ethylene molar content of 4 parts by weight based on the functional group-containing vinylidene fluoride-based polymer A 7 %) 1 part by weight, a spherical natural graphite powder (manufactured by Continental) of 88 parts by weight ' and 67 parts by weight of NMP were mixed to prepare a negative electrode electrode depolarizing mixture composition A of the present invention. The obtained electrode depolarization mixture was applied to 8 // m aluminum copper, uniformly coated to obtain a film thickness of about 100 μm after drying, and dried at 130 t for 25 minutes to obtain a negative electrode structure A (active material mass: 163 g/m 2 ) ). (Method for Measuring Peel Strength of Electrode Structure Electrode Depolarization Mixture Layer) The negative electrode structure coated with the current collector is used as a sample, and the electrode depolarization mixture layer is peeled from the collector, according to ns K 6854 The 1 80 peel test was measured. -12 - (9) (9) 1330902 (Measurement of peel strength) The peel strength of the negative electrode structure A was measured and found to be 3 8 gf / (manufactured by a battery). The positive electrode structure of the 48 mm x 48 mm mounted charge and discharge reed was cut and cut. 50mmx50mm mounting charge and discharge reed negative electrode structure A' electrode surface relative to the intervention 52mmx52mm thickness 2〇ym poly-bine aluminum laminated packaging material 'will reed exposed external combination, ethylene carbonate / methyl ethyl carbonate After adding 1 g of an electrolyte containing 1 Torr of Li PF 6 to an ester/dimethyl carbonate (9/]3/] 3 volume ratio), the aluminum laminated packaging material made of polyethylene was sealed to obtain the present. Battery A of the invention. (Charge and Discharge) The above battery A was charged to 4.2 V at a constant current of 0.2 mA, discharged to 3.0 V at a constant current of 0 2 mA, and charged to 4.37 V at a constant current of 1 mA. The charging capacity (charging current 値 integral 値) of the battery charging 2 times is 1 3 3 m A. (Nail test) The above-mentioned charged battery A was placed in a room at room temperature of 23 C, and the negative electrode was placed on a wooden board for a month, and then pierced through a 1 mm nail. The infrared temperature recorder (AVIONIX, Japan) "TVS-100") Measure -13 (10) 1330902 The rise of the surface temperature of the battery. The maximum temperature rise after battery A nailing is 3 t. &lt;Example 2&gt; The negative electrode was produced in the same manner as in Example 1 except that polyacrylic acid (PAA) ("AQUPEC HV-501" manufactured by Sumitomo Seiko Co., Ltd.) was used instead of EVOH to obtain a negative electrode structure B and a battery B. The peel strength of the negative electrode structure B was 1.0 g f / m m , the charge capacity of the battery b was 135 m Ah, and the maximum temperature rise of the nail test was 3.5. (Example: &lt;Example 3 &gt; Preparation of a negative electrode, using a functional group-containing vinylidene fluoride polymer B&amp; functional group vinylidene fluoride polymer A, the negative electrode structure C was carried out in the same manner as in Example 1, and the battery was used. C. The peeling strength of the negative electrode structure C was 4.3 gf/mm, the battery capacity was 1 30 mAh, and the maximum temperature rise of the nail penetration test was 3 t. Substituting, obtaining ···&lt;Example 4 &gt; Production of negative electrode In the same manner as in Example 1, except that hydroxyethyl cellulose (HEq (MARUKALINKER EP-85 5 j Japan DAICEL Chemical Industry Co., Ltd.) was used instead of EV Η 负极, a negative electrode structure was obtained || D battery D. Negative electrode structure D The peeling strength was 〇_9gf/mm, the battery capacity was 133 mAh, and the maximum temperature rise of the nail test was 3 deaths. -14 - (11) 1330902 &lt;Example 5 &gt; Preparation of the negative electrode, using poly P A vinyl phenol (PPVP) ("MARUKALINKER S-2P" manufactured by Nippon DA1CEL Chemical Co., Ltd.) was used in the same manner as in Example 1 except that EVOH was used, and a negative electrode structure Η and a battery Η were obtained.

The peel strength of the negative electrode structure was 5.4 gf/m m, the charge capacity of the battery crucible was 134 m Ah, and the maximum temperature rise of the nail penetration test was 4 °C. &lt;Comparative Example 1&gt; The preparation of the negative electrode was carried out in the same manner as in Example 1 except that the functional group-containing vinylidene fluoride polymer A was increased from 11 g to 12 g, and EVOH was used, to obtain a negative electrode structure E and a battery E. The peel strength of the negative electrode structure E was 0.9 gf/mm, the charge capacity of the battery E was I 3 3 m A h , and the maximum temperature rise of the nail penetration test was 12 2X. <Comparative Example 2> The negative electrode was produced by using the functional group-containing vinylidene fluoride polymer B from [lg] to 2 g, and the negative electrode structure F was obtained in the same manner as in Example 3 except that EVOH was not used. F. The peel strength of the negative electrode structure F was 3.1 gf/mm, the charge capacity of the battery E was 124 mAh, and the maximum temperature rise of the nail penetration test was 6.5 °C. &lt;Comparative Example 3 &gt; -15- (12) 1330902 The preparation of the negative electrode was carried out in the same manner as in Example 7 except that the functional group-containing vinylidene fluoride polymer C was used as the functional vinylidene fluoride polymer A. Negative electrode structure G, battery G. The peel strength of the negative electrode structure G was 0.7 gf/mm, the charge capacity of the battery g 4 to β was 134 mAh, and the maximum temperature rise of the nail penetration test was 6 t. &lt;Comparative Example 4 &gt;

The negative electrode was produced in the same manner as in Comparative Example 1, except that the functional group-containing vinylidene fluoride polymer C was used instead of the functional group-containing vinylidene fluoride polymer A, to obtain a negative electrode structure Η and a battery crucible. The peel strength of the negative electrode structure G was 0.7 gf/mm, the charge capacity of the battery G was 1 3 2 m A h, and the maximum temperature rise of the nail penetration test was 9 °C. The summary of the adhesive compositions used in the above examples and comparative examples and the evaluation results are summarized in Table 1 below. .·· -16- (13)1330902

Table I Adhesive Composition Evaluation Results Item Partial Fluoride Derivative Polymer Polar Polymer Peel Strength (gf/mm) Charging Capacity (mAh) Maximum Temperature Rise After Sting C) Example 1 A VDF/MMM = 99.5/ 0.5 EVOH 3.8 133 3 Example 2 A PAA 1.0 135 3.5 Example 3 B VDF/2M-GMA 100/0.75 EVOH 3.4 130 3 Example 4 A HEC 0.9 133 3.5 Example 5 A PPVP 5.4 134 4 Comparative Example 1 A te / » 3.4 130 12 Comparative Example 2 BM / * 3.1 124 6.5 Comparative Example 3 C VDF = 100 EVOH 0.7 134 6 Comparative Example 4 CM *»\&gt; 0.7 132 9

··In the field of industrial use, it can be seen from the above Table I that the non-aqueous electrolyte battery having the positive electrode and the negative electrode capable of absorbing and releasing lithium has a functional group-based vinylidene fluoride-based binder. Non-aqueous electrolyte of polymer and polar polymer -17- (14) 1330902 The composition of the binder for the pool electrode, it is known that the electrode with excellent bonding property and the battery with excellent safety can be obtained. ·· ·· -18-

Claims (1)

1330902 Pickup, Patent Application No. 92 1 3 2 6 1 1 Patent Application Revision of Chinese Patent Application Revision of the Republic of China on June 18, 1999 1 · A solution forming adhesive for non-aqueous electrolyte battery electrodes A binder composition comprising a positive electrode and/or a negative electrode binder for a nonaqueous electrolyte battery capable of absorbing and releasing lithium and a negative electrode, characterized by at least (a) a functional group-containing vinylidene fluoride polymer And (b) a polar polymer selected from the group consisting of ethylene vinyl alcohol copolymer, cellulose polymer, ethylene phenol polymer, polyacrylic acid, polyacrylic acid crosslinked polymer and polyethylpyrrolidone The above-mentioned (A) functional group-containing vinylidene fluoride-based polymer, and ( ) polar polymer are simultaneously dissolved in N-methyl-2-pyrrolidone, hydrazine, hydrazine-methylformamide, hydrazine , at least one polar organic solvent selected from the group consisting of Ν-dimethylacetamide, hydrazine, hydrazine-dimethyl sulfoxide, hexylphosphine amide, triethyl phosphate and acetone, and forming a solution . 2. The non-aqueous electrolyte battery electrode solution-forming adhesive composition according to the first aspect of the invention, wherein the negative electrode is made of a carbon material. 3. The non-aqueous electrolyte battery electrode solution-forming adhesive composition according to claim 1, wherein the functional group-containing vinylidene fluoride polymer is fluorinated vinylidene fluoride, and has a carboxyl group or an epoxy group. The positive group of propyl is formed from a copolymer of alkene 1330902. 4. An electrode depolarizing mixture for a non-aqueous electrolyte battery electrode, characterized by comprising a binder according to any one of claims 1 to 3, a composition and an electrode active material. 5. An electrode for a non-aqueous electrolyte battery electrode, characterized in that the current collector has an electrode depolarization layer formed by the electrode depolarization mixture of claim 4 of the patent application. 6 · A non-aqueous electrolyte battery characterized in that at least one of the positive electrode and the negative electrode is an electrode containing the fifth item as claimed in the patent application. -2-