MXPA99011638A - Solid electrolytic secondary battery - Google Patents

Abstract

A solid electrolytic secondary battery comprising a positive electrode, a negative electrode and a solid electrolyte interposed between the electrodes, wherein the solid electrolyte contains, as matrix polymer, fluorine polymer having a weight-average molecular weight (Mw) of 550,000 or larger, which polymer delivering an excellent adhesiveness to the active material layers of the positive and negative electrodes, thereby enabling a polymer sold electrolyte or a gel electrolyte to be bonded to electrode active material layers with a sufficient adhesive strength. In view of a paint viscosity, fluorine polymer having a weight-average molecular weight (Mw) of not smaller than 300, 000 and less than 550,000 may be jointly used.

Description

SOLID ELECTROLYTE SECONDARY BATTERY Technical Field The present invention relates to a secondary solid electrolyte battery having a solid electrolyte (also gel type electrolyte) placed between a positive electrode and a negative electrode, and more particularly, a secondary battery of Novelty solid electrolyte capable of a greater number of charge and discharge cycles, which is one of the operating characteristics for secondary batteries in practical use, and which can be manufactured with higher productivity Background of the Technique In recent years, many Portable devices such as an integrated VTR / video camera unit, portable telephone, laptop, etc. have been proposed, and have a tendency to be more compact for improved portability.Many developments and investigations have been made to provide a more battery thin and foldable, more specifically, a sec battery or a lithium-ion battery, among others, for use as a portable power source in such more compact portable electronic devices. In order to obtain said thinner and more bendable battery structure, active investigations have been made in relation to a solidified electrolyte for use in batteries. Especially, a gel electrolyte containing a plasticizer and a solid polymer electrolyte made of a highly molecular material having lithium salts dissolved therein is what is attracting much attention from many fields of industry. Highly molecularly useful materials have been reported to produce a highly molecular solid electrolyte: a silicone gel, acrylonitrile, modified polyphosphaze polymer, polyethylene oxide, polypropylene oxide, its composite polymers, crosslinking polymers, modified polymers, etc. In the conventional secondary battery that makes use of a solid electrolyte made of one of these highly molecular materials, however since the electrolyte film does not have sufficient strength and adhesion to the battery electrodes, there is a lack of uniformity between the currents of loading and unloading, and a lithium dendrite easily occurs. For this reason, the conventional secondary battery has a short life of charge and discharge cycles (number of charge and discharge cycles), mainly, it is critically disadvantageous that it can not satisfy the requirements of "stable utility for a long time" being this one of the important basic requirements for the production of a commercial article. In addition, for a larger film strength of a solid electrolyte, it has been proposed to crosslink a tri-functional polyethylene glycol with a diisocyanate derivative by reaction therebetween (as disclosed in Japanese Patent Laid-Open Publication No. 62-48716) or the cross-linking of polyethylene glycol diacrylate by polymerization (as disclosed in Japanese Patent Laid-Open Publication No. 62-285954). Due to an unreacted substance or a solvent used for the remnants of the reaction, the electrolyte does not have sufficient adhesion on the battery electrodes. In addition, the indispensable drying process causes productivity to be low. These methods are required for further improvement. As mentioned above, the highly molecular solid or the gel electrolyte has excellent characteristics-not found in solid electrolytes. This is because the solid electrolyte or gel does not flow like the liquid electrolyte. The contact of the highly molecular solid or electrolyte gel with the electrodes has a great influence on the operation of the battery. Mainly, if the contact between them is poor, the resistance of the contact between the highly molecular solid or electrolyte gel and the electrodes of the battery is such that the internal resistance of the battery is very large. Also, there can be no ideal ion movement between the highly molecular solid or electrolyte gel and the electrodes, so that the capacity of the battery is also low. If such a battery is used for a long period, "a non-uniformity occurs between the discharge and charge currents and a lithium dendrite may occur, therefore, in a battery that uses a highly molecular solid or gel electrolyte, It is extremely important to adhere the highly molecular solid or gel electrolyte to layers of active material of battery electrodes with sufficient adhesive force To implement the above, it has been proposed as in Japanese Patent Unquoted Publication No. 2-40867 use a positive electrode compound in which a highly molecular electrolyte is added to a positive active material layer of the positive electrode In a battery disclosed in the Japanese Patent Unreported Publication, a portion of the highly molecular solid electrolyte is mixed with " The layer of positive active material to improve the electrical contact between the highly molecular solid electrolyte and the layer of active material of the positive electrode. However, in case the method disclosed in Japanese Patent Laid-Open Publication No. 2-40867 is adopted, the positive electrode compound to which the highly molecular solid electrolyte is added must be used to produce a positive plate and the High molecular solid electrolyte must be laminated on the positive plate. You can not get an ideal contact between the positive plate and the solid electrolyte. More specifically, if a solid electrolyte having an irregular surface is laminated to an electrode layer, good adhesion can not be ensured and the internal strength is increased, with the result that the charging characteristic becomes worse. Also, a positive or negative electrode compound in which a highly molecular solid or electrolyte gel is added can not be easily compressed sufficiently due to the elasticity of the highly molecular solid or electrolyte gel, and the separation between the grains within the compound is large, with the result that internal resistance increases. Also in this case, the charging characteristic becomes worse. Additionally, to prevent an electrolyte salt contained in the highly molecular solid or electrolyte gel from being dissolved, the positive or negative electrode must be produced at low humidity, its quality is not easily controllable and the manufacturing costs are high. Presentation of the Invention Accordingly, the present invention has the objective of overcoming the disadvantages indicated above by the prior art by providing a solid electrolyte with excellent adhesion on the layers of active material of the electrodes, and thereby providing a secondary battery of solid electrolyte using in it the solid electrolyte to ensure a good electrical contact between the solid electrolyte and the active material layer of a positive electrode or negative electrode of the battery. Also, the present invention has the objective of providing a secondary battery of solid electrolyte adapted to have an ideal grain separation in the active material layers of the positive and negative electrodes, an improved charge and discharge life cycle and high productivity.

To obtain the objective indicated above, the Inventors have carried out several investigations over a long period. As a result of the investigations, it has been found that the molecular weight of a fluorocarbon polymer used as a matrix polymer in the solid electrolyte has a great influence on the characteristics of the electrolyte, the use of a high molecular weight fluorocarbon polymer makes it possible Adhere a highly molecular solid or electrolyte gel to the active material of the electrodes with sufficient strength and provide a good electrical contact between the solid or gel electrolyte and the active material of the positive or negative electrodes, and that the use of said fluorocarbon polymer allows provide a secondary solid electrolyte battery with longer charge and discharge life cycle and excellent productivity. The secondary solid electrolyte battery according to the present invention is completely based on the above findings of the Inventors and comprises a positive electrode and a negative electrode and a solid electrolyte provided between the electrodes, the solid electrolyte containing as a matrix polymer a Fluorocarbon polymer of average molecular weight of 550,000 or more.

/ Note that the term "solid electrolyte" used herein refers to a solid electrolyte as well as an electrolyte gel in which a matrix polymer is plasticized by a plasticizer, for example. Therefore, the secondary solid electrolyte battery of the present invention also includes a secondary battery of electrolyte gel. In accordance with the present invention, a fluorocarbon polymer of average molecular weight of 550,000 or more (Mw) is used as the matrix polymer. The fluorocarbon polymer of average molecular weight of 550,000 or more ensures excellent adhesion of the electrolyte to the active material of the positive and negative electrodes. Therefore, it is possible to adhere the highly molecular solid or electrolyte gel to the active material of the electrodes with sufficient strength and thereby reduce the internal resistance of the electrodes, thereby enabling obtaining an improved charge and discharge cycle of the battery. These objects and other objects, features and advantages of the present invention will be more apparent in the following detailed description of the preferred embodiments of the present invention when taken in conjunction with the accompanying drawings. Brief Description of the Drawings FIGURE 1 presents a characteristic curve of the correlation between the average molecular weight (Mw), average number of molecular weight (Mn) and the logarithmic number of viscosity (dl / g) / FIGURE 2 is a view of cutting an experimental battery of the present invention; and FIGURE 3 is also a sectional view of the detachment test equipment. Preferred Modality of the Invention The secondary solid electrolyte battery according to the present invention uses a fluorocarbon polymer as the matrix polymer. Fluorocarbon polymers useful as a matrix polymer in the solid electrolyte of the present invention include, for example: polyvinylidene fluoride, vinylidene fluoride and hexafluoropropylene copolymer, vinylidene fluoride and tetrafluoroethylene copolymer, vinylidene fluoride copolymer and trifluoroethylene, etc. However, the fluorocarbon polymer is not limited to these examples only. The fluorocarbon polymer used as the matrix polymer should have an average molecular weight of 550,000 or more. If the fluorocarbon polymer has an average molecular weight of less than 550,000, it does not have sufficient adhesive strength. Note that as the fluorocarbon polymer has an increased average molecular weight of 300,000, it has a gradually increasing adhesive force. However, the adhesive strength ensured by an average molecular weight of less than 550,000 is not always sufficient. To ensure sufficient adhesive strength, the average molecular weight (Mw) must be greater than 550,000. The fluorocarbon polymer should desirably have an average molecular weight of more than 550,000; however, for an average molecular weight greater than 3,000,000, the polymer range has to be decreased to an impractical dilution range. The solid electrolyte or gel is produced using, either alone or as a component of the plasticizer, esters, ethers or carbonates usable in a battery to prepare a solution of the highly molecular compound, salt electrolyte and solvent (and an additional plasticizer for an electrolyte gel), impregnate the solution in the active material of the positive or negative electrodes, and remove the solvent to solidify the electrolyte. Therefore, the esters, ethers or carbonates usable in the battery are limited by themselves. Esters, ethers or carbonates included in the limited range that have an average molecular weight of more than 1,000,000 do not have sufficient solubility to prepare an adequate solution. Therefore, the average molecular weight (Mw) of the fluorocarbon polymer should preferably be in the range between 550,000 and 3,000,000, and more preferably between 550,000 and 1,000,000. In case of using a fluorocarbon polymer of 550,000 or more of average molecular weight (Mw), another fluorocarbon of more than 300,000 or less than 550,000 Mw can be used in combination to lower the viscosity to facilitate the formation of an electrolyte film . In this case, however, the ratio of the fluorocarbon polymer of Mw of 550,000 or more should preferably be 30% or more by weight. If the ratio of the fluorocarbon polymer of 550,000 Mw or more is less, it will be difficult to ensure sufficient adhesion strength of the solid electrolyte. The Mw fluorocarbon polymer of 550,000 is prepared using a peroxide or by polymerizing a monomer at a temperature between room temperature up to 200 ° C and under atmospheric pressure of 300 or less. It is produced industrially by polymerization processes by suspension or emulsion polymerization. In the suspension polymerization process, water is used as the medium, a dispersant is added to the monomer to disperse the latter as liquid droplets within the medium, the organic peroxide dissolved in the monomer is polymerized as a polymerization initiator. Also, during the polymerization by suspension of the monomer in the medium in the presence of an oil-soluble polymerization initiator (referred to as "initiator" hereinafter), a monomer selected from hexafluoropropylene, ethylene tetrafluoride, etc. it can be used as a copolymer component between 1 and 7% by weight of all monomers to provide a copolymer. The hexafluoropropylene or ethylene tetrafluoride can be fully added into a polymerization vessel during initial charging. Otherwise, it may be added partially or totally in a divided or continuous manner to the polymerization vessel after the initial charge. A chain transfer agent at this time includes acetone, isopropyl acetate, ethyl acetate, diethyl carbonate, dimethyl carbonate, calcined ethyl carbonate, propionic acid, trifluoroacetic acid, trifluoroethyl alcohol, formaldehyde dimethyl acetal, epoxide 1, 3-butadiene, 1,4-dioxane, β-butyl lactone, ethylene carbonate, vinylene carbonate or the like. Among them, however, acetone or ethylene acetate should preferably be used for ease of availability and handling. The initiator may be one of dinormal propyl peroxydicarbonate (NPP), diisopropyl peroxydicarbonate or the like. For each initiator or chain transfer agent, a class and amount can be selected and one or more of two types used to obtain a desired molecular weight. The dispersant used in the electrolyte preparation process can be one of partially suspended polyvinyl acetate used in ordinary suspension polymerization, a water soluble cellulose ether such as methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose or the like, a water soluble polymer such as gelatin, for example. The water, monomer, dispersant, initiator, chain transfer agent and other auxiliaries may be charged in any manner suitably used in ordinary suspension polymerization. For example: the water, dispersant, initiator, chain transfer agent and other auxiliaries are charged, and placed under a reduced pressure to remove the air, the monomer is charged and agitation of the mixture is initiated. After the mixture reaches a predetermined temperature, it is maintained at that temperature to continue with the polymerization. When the conversion reaches, for example: 10 to 50% the chain transfer agent is loaded under pressure. The polymerization is allowed to continue. When the conversion reaches 80% or more, for example, unreacted monomer is recovered. The polymer is then dehydrated, washed and dried to provide a polymer. By controlling the temperature, pressure and reaction time appropriately at this time, it is possible to provide a high molecular weight fluorocarbon polymer of 550,000 or more of average molecular weight. The fluorocarbon polymer thus produced forms, together with the electrolyte salt and solvent (in addition to a plasticizer for an electrolyte gel), a solid or gel electrolyte. The electrolyte is provided between a positive electrode and a negative electrode. At this time, the fluorocarbon polymer must be impregnated in the state of solution within the active material of the positive or negative electrodes, and remove the solvent for solidification of the electrolyte. Thereby a part of the electrolyte is impregnated into the active material of the positive or negative electrodes to provide a greater adhesive force which can ensure an improved adhesion of the electrolyte to the electrodes. In solid electrolyte or gel, the matrix polymer is used between 2 and 30% by weight and an ester, ether or carbonate is used as a component of the solvent or plasticizer. The solid electrolyte or gel contains lithium salt which can be used in ordinary battery electrolytes. More particularly, the lithium salt may be one selected from lithium chloride, lithium bromide, lithium iodide, lithium chlorate, lithium perchlorate, lithium bromate, lithium iodate, lithium nitrate, tetrafluorolithium borate, phosphate hexafluorolithium, lithium acetate, lithium bis (trifluoromethanesulfonyl) imide, LiAsF6, LiCF3S04, LiC (S02CF3) 3, LiAlCl4, LiSiF6 / etc. These lithium salts can be used alone or in combination mixed together, but among them, LiPF6 and LiBF desirably should be used for oxidation stability. The concentration of the solution of the lithium salt should preferably be between 0.1 and 3.0 mols / liter in the plasticizer for gel electrode, and more preferably between 0.5 and 2.0 mols / liter. The secondary solid electrolyte battery according to the present invention can be constructed similarly to the conventional lithium ion secondary battery provided using the solid electrolyte or gel mentioned above. That is, the negative electrode of a lithium-ion battery can be made of a material from which the lithium ion can be introduced or extracted. The material for the negative electrode can be, for example, a carbon material such as a carbon material difficult to be graphitized or a graphite material. More particularly, the material may be one selected from carbon materials such as pyrocarbons, cokes (peat coke, needle coke, petroleum coke), graphites, vitreous carbons, highly molecular organic sedimented compounds (phenol resin, furan resin or the like sintered at appropriate temperature for carbonization), carbon fiber, activated carbon and the like. further, it can be a material from which the lithium ion can be inserted or extracted, including highly molecular compounds such as polyacetylene, polypropyl, etc., oxides such as SnO;, etc. To form a negative electrode of said materials, a known binder or the like can be added to the material. The positive electrode can be formed from a metal oxide, metal sulfide or a special highly molecular compound used as positive electrode active material depending on the type of battery intended. For a lithium ion battery, for example: the active material of the positive electrode may be a metal sulfide or oxide without lithium such as TiS2, MoS2, NbSe2, V2? 5 or similar, or a lithium oxide compound or the like containing LiM02 as a base (M is one or more transition metal, and x differs depending on the degree of charge or discharge of the battery, usually about 0.05 and below 1.10). The transition metal M that forms the lithium oxide compound should preferably be Co, Ni, Mn or the like. More particularly, the lithium oxide compound includes LiCo02, LiNi02, LiNiyCOi-y02 (0 << and l), LiMn204. These lithium oxide compounds can be an active material of the positive electrode that allows to generate high energy and an excellent energy density. The positive electrode can be formed from more than one of these active materials.

To form a positive electrode of any of these active materials, a well-known conductive material, a binder or the like can be added to the active material. The battery according to the present invention is not limited to a particular shape, but can be designed to have a cylindrical, square, rectangular, coin, button or any other shape. Also, the battery according to the present invention can be freely dimensioned, whether large, thin or otherwise. The present invention will be further described below in terms of the experimental modalities of the battery based on experimental results. Example of polymerization conditions for fluorocarbon polymer. The following monomers and auxiliaries were loaded in a pressure-resistant autoclave made of stainless steel of a volume of 14 liters, and the polymerization was started at a temperature of 25 ° C: Vinylidene fluoride 93 parts by weight (3,000 grs.) Hexafluoropropylene 7 parts by weight Purified water 300 parts by weight Methylcellulose 0.1 parts by weight Sodium pyrophosphate 0.2 parts by weight 1 (9 NPP O.ßl parts by weight Between 3 and 24 hours after starting the polymerization (when the conversion between 30 and 80%), 3.0 parts by weight of vinyl acetate were added to the mixture and the polymerization was allowed to proceed, when the internal pressure of the polymerization vessel decreased to 50% of the equilibrium pressure after the polymerization The unreacted monomer was recovered, the polymer mixture thus produced was dehydrated, washed and dried.Determination of molecular weight a. molecular (Mw / Mn) A gel permeation chromatograph (series 8010 of Toso, with two TSK-GEL GMHXL columns of 7.8 mm diameter, 300 mm long, connected in series) was used to measure average weight of weight Molecular (Mw) of a dimethyl acetoamide solution in which the polymer powder obtained as above was dissolved at a concentration of 0.2% by weight at a temperature of 40 ° C and flow rate of 0.8 ml / minute. b. Analysis of polymer composition. The compound was measured using 19 F NMR. c. Logarithmic number of viscosity. An Ubbelohde viscometer was used to measure an emanation time at 30 ° C of a solution in which the polymer powder was dissolved in dimethylformamide at a concentration of 4 grams / liter. The following equation was used to calculate a logarithmic number of viscosity of a measured time of emanation: logarithmic number of viscosity [D] = ln (Drel) / C (dl / g) where Drel: emanation time of the solution shows / solvent emanation time C: Concentration of the sample solution (0.4 g / dl) FIGURE 1 shows the correlation between the weight average molecular weight (Mw), the average molecular weight number (Mn) and the logarithmic viscosity number . Experimental mode 1 First, the negative electrode was prepared as follows: Ninety parts by weight of ground graphite powder and 10 parts by weight of vinylidene fluoride / hexafluoropropylene copolymer as binder were mixed together to prepare a negative electrode mixture. The mixture was dispersed in N-methyl-2-pyrilidone to produce a paste mixture. The pasty mixture was uniformly applied on one side of a strip of copper sheet 10 Dm thick, used as an anode collector. After drying the pasty mixture, the copper foil strip was compressed by means of a roll press to prepare the negative electrode. On the other hand, the positive electrode was prepared as follows: To produce an active material of the positive electrode (LiCo02), lithium carbonate and cobalt carbonate were mixed at a ratio of 0.5 mol to 1 mol and sedimented in the atmosphere at 900 ° C for 5 hours.

Ninety-one parts by weight of LiCo02 thus produced, 6 parts by weight of graphite as conductive material and 10 parts by weight of vinylidene fluoride / hexafluoropropylene copolymer were mixed together to prepare the positive electrode mixture. The mixture was further dispersed in N-methyl-2-pyrilidone to produce a pasty mixture. The pasty mixture was uniformly applied on one side of a 20 Dm thick sheet of aluminum sheet used as the cathode collector. After drying the pasty mixture, the aluminum foil strip was compressed and formed by the roll press to produce the positive electrode. Additionally, a solid electrolyte (or gel electrolyte) was prepared as follows: The positive and negative electrodes were applied uniformly with a solution in which 300 parts by weight of a plasticizer composed of 42.5 parts by weight of ethylene carbonate (EC), 42.5 parts by weight of propylene carbonate (PC) and 15 parts by weight of LIPF6, 10 parts by weight of polyvinyl fluoride as matrix polymer of 600,000 average molecular weight (logarithmic viscosity number of 1.93) and 60 parts by weight of diethyl carbonate were mixed and dissolved. With this, the solution was impregnated on the electrodes. The electrodes remained at normal temperature for 8 hours. Then, the dimethyl carbonate was vaporized for removal to provide an electrolyte gel. The positive and negative electrodes applied with the electrolyte gel were superposed one on top of the other so that the electrolytes on them were opposite one another, and a pressure was applied to the electrodes, thereby preparing a flat battery of 2.5 cm gel electrode by 4.0 cm of area and a thickness of 0.3 mm. FIGURE 2 schematically illustrates the prepared battery. As shown, a negative electrode having an anode collector 1 in which a layer of active material anode 2 was formed, a positive electrode with a cathode collector 3 in which a layer of cathode active material 4 is formed, and an electrolyte gel 5 applied to the layers of anode and cathode active material, respectively. Experimental mode 2 A flat gel electrolyte battery was prepared in a manner similar to experimental mode 1 as described above except that 7 parts by weight of a polyvinylidene fluoride of 700.00 average molecular weight (Mw) and 3 Parts by weight of a polyvinylidene fluoride of 300,000 average molecular weight (Mw) were used as a matrix polymer. Experimental mode 3 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) weight of 600,000 (the hexafluoropropylene content was of 7.0% by weight measured by NMR) was used as a matrix polymer. Experimental mode 4 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) weight of 700,000 (the hexafluoropropylene content was of 7.0% by weight measured by NMR) and a vinylidene fluoride / hexafluoropropylene copolymer having an average molecular weight (Mw) weight of 300,000 (the hexafluoropropylene content was 7.0% by weight as measured by NMR) were used as matrix polymers at a weight ratio of 7: 3. Experimental mode 5 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) of 800,000 (the hexafluoropropylene content was of 7.0% by weight measured by NMR), a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) of 600, 000 (the hexafluoropropylene content was 7.0% by weight as measured by NMR) and a vinylidene fluoride / hexafluoropropylene copolymer with an average molecular weight (Mw) weight of 300,000 (the hexafluoropropylene content was 7.0% by weight as measured by NMR) were used as matrix polymers at a weight ratio of 3: 3: 4. Experimental mode 6 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a vinylidene fluoride / hexafluoropropylene copolymer with an average molecular weight (Mw) weight of 2,000,000 (the hexafluoropropylene content was 7.0% by weight measured by NMR) was used as matrix polymer. Comparative Example 1 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) weight of 300,000 (the hexafluoropropylene content was of 7.0% by weight measured by NMR) was used as a matrix polymer. Comparative Example 2 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a vinylidene fluoride / hexafluoropropylene copolymer with an average molecular weight (Mw) weight of 500,000 was used as the matrix polymer. . Comparative Example 3 A flat gel electrolyte battery was prepared in a manner similar to the experimental mode 1 described above except that a copolymer of vinylidene fluoride / hexafluoropropylene with an average molecular weight (Mw) of 380,000 (the hexafluoropropylene content was of 7.0% by weight measured by NMR) was used as a matrix polymer. Evaluation The experimental modalities 1 to 6 and the comparative examples 1 to 3 were tested for resistance to detachment, and additionally in loading and unloading cycles. The peel strength was measured as follows. An electrode layer of active material 12 was formed in an electric collector 11, and an electrolyte gel 13 was applied on the active material 13, as shown in FIGURE 3. The test piece thus prepared was pulled in the direction of the arrow ( 180 °) with a weight of 500 grams at a speed of approximately 10 cm / second. The results are presented in Table 1 with a mark (o) for the fracture of the electrolyte gel 13 at the end of the electrode active material layer 12 and a mark (x) for the separation of the electrolyte gel 13 and the material layer Active electrode 12 of the union between them. On the other hand, the load cycle discharge test was done during 500 cycles by downloading the theoretical capacity (0.5C) during 2 hours (hourly speed). Each of the batteries was evaluated as follows.

/ Each battery was charged at constant current and voltage at a temperature of 23 ° C up to the upper limit of 4.2 V, and then discharged at constant current (0.5C) to a final voltage of 3.2 V. The discharge capacity was thus determined and evaluated with a discharge output maintenance factor after 500 cycles of loading and unloading. The results of the test are presented in Table 1. Table 1 Resistance- Maintenance factor of Cia Discharge to discharge (0.5C) arrest after 500 cycles Modality 1 0 85% Modality 2 0 90% Modality 3 0 92% Modality 4 0 95% Modality 5 0 95% Modality 6 0 93% Example 1 X 48% Example 2 X 55% Example 3 X 50% As it is apparent from Table 1, each of the experimental modalities using the fluorocarbon of 550,000 or more than average molecular weight (Mw) weight as electrolyte gel showed excellent peel strength and also an excellent output maintenance factor after the test cycle. Experimental mode 6 using a fluorocarbon polymer with 2,000,000 average molecular weight (Mw) is excellent in peel strength and output holding factor as shown, but showed a not so good productivity due to its high viscosity. As described above, the present invention can provide a solid electrolyte with excellent adhesion to the active material layers of the electrode, and therefore the present invention can also provide a secondary battery of solid electrolyte with a solid electrolyte with a good electrical contact with the layers of positive and negative active material and with a significantly improved life cycle of loading and unloading.

Claims (1)

1. CLAIMS A secondary battery of solid electrolyte, comprising: a positive electrode; a negative electrode, and a solid electrolyte provided between the electrodes; the solid electrolyte contains as the matrix polymer a fluorocarbon polymer of 550,000 or more of average molecular weight. The secondary solid electrolyte battery as set forth in Claim 1, wherein the solid electrolyte contains as a matrix polymer: a fluorocarbon polymer of more than 300,000 and less than 550,000 average molecular weight; and a fluorocarbon polymer of 550,000 average molecular weight. to a secondary solid electrolyte battery as set forth in Claim 2, wherein the matrix polymer contains 30% or more by weight of the fluorocarbon polymer of 550,000 or more of average molecular weight. to a secondary solid electrolyte battery as set forth in Claim 1, wherein the fluorocarbon polymer is at least polyvinylidene fluoride or vinylidene fluoride / hexafluoropropylene copolymer. The secondary solid electrolyte battery as set forth in Claim 1, wherein a binder containing positive and / or negative electrode is made of a high polymer material. which is the same or similar in molecular structure to the matrix polymer of the solid electrolyte. The secondary solid electrolyte battery as set forth in Claim 1, wherein the negative electrode contains a material within which a lithium ion can be inserted or extracted. to a solid electrolyte secondary battery as set forth in Claim 1, wherein the material from which the lithium ion can be inserted or extracted is a carbon material. to a solid electrolyte secondary battery as set forth in Claim 1, wherein the positive electrode contains a lithium compound oxide and a transition metal. to a solid electrolyte secondary battery as set forth in Claim 1, wherein the solid electrolyte layer is formed on at least one of the opposite faces of the positive or negative electrodes, respectively, by impregnating on the face a solution in which the Solid electrolyte is dissolved and removing the solution from the face.