CA2118401C

CA2118401C - Battery and its manufacturing method

Info

Publication number: CA2118401C
Application number: CA002118401A
Authority: CA
Inventors: Kazunari Takeda; Syuichi Izuchi
Original assignee: Yuasa Corp
Current assignee: GS Yuasa International Ltd
Priority date: 1993-02-23
Filing date: 1994-02-18
Publication date: 2004-08-17
Anticipated expiration: 2014-02-18
Also published as: DE69421238T2; EP0643434A1; US5658687A; JP3136610B2; WO1994019840A1; DE69421238D1; CA2118401A1; EP0643434A4; EP0643434B1

Abstract

A battery, in which the content of material remaining in the battery interior caused by an ion-conductive high-molecular compound to bring about lowering of battery performance such as expansion and short-circuiting etc. of battery, is controlled to 0.1 wt% or smaller. Sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid, etc. for example, may be mentioned as this material.

Description

BATTERY AND ITS MANUFACTURING METHOD
This invention relates to a battery operating reversibly under an environmental temperature, the cathode, electrolyte and anode of which are improved, and to a method for manufacturing the battery.
With the recent tendency to design various electrical equipment in micro-electronic form, a battery has been housed in the equipment and integrated with the electronic elements and the circuit, the battery serving as a source for memory back-up of the various elements of the equipment. For this reason, there is an increased demand for minimizing the size, weight and thickness of the battery, and for a battery having a large energy density. In the field of primary batteries, a small-sized and light-weight battery such as a lithium battery has already been put to practical use. However, its field of application is limited to a small region. Under these circumstances, in the field of secondary batteries, a battery using a nonaqueous electrolyte, which can be made small in size and weight, has attracted attention as an alternative to the conventional lead or nickel-cadmium battery. However, in a battery utilizing the non-aqueous electrolyte, an electrode active material that can satisfy the practical physical properties, such as the cycle characteristics and the self-discharge characteristics, has not yet been found.
In order to obtain a small-sized and light-weight battery having a large energy density and a high reliability, it is necessary to examine the following problems (1) and (2).

-2-(1) Problem of the electrode active material and the electrode; and (2) Problem of the electrolyte.
As for problem (1), the inventor examined a film type battery, that is a battery having unit cells with thicknesses of 100 to 500 hum, also called a "sheet-shaped" battery. In this kind of battery, however, problems arise in that the manufacture of metallic lithium foil having the desired performance is somewhat difficult from a technical point of view, and the manufacturing process became complicated.
Further, in a secondary battery, there was formation of lithium dendrite, and passivation of the interface took place so that the use of metallic lithium was restricted.
Therefore, investigations on the use of alloys, including lithium metals as represented by lithium-aluminum, lithium-lead and lithium-tin, are being carried on actively. However, the electrode was cracked or broken into fine pieces due to repeated charging and discharging, so that the cycle characteristic was not improved even when these alloys were used, because these alloys have small strengths as represented by the lithium-aluminum alloy. As an alternative method for restricting the formation of lithium dendrite, investigations on the selection of an electrolyte salt and improvement in the separator are being tried. As for the separator, it is now being attempted to restrict the formation of lithium dendrite by laminating non-woven fabrics made of polypropylene and non-woven fabrics made of glass fiber, which have so far been used. However, a substantial solution has not yet been found.

-3-Accordingly, electrode active materials utilizing the intercalation or doping phenomenon of the layer compound are especially being studied now in many research organizations.
These materials are noted for their excellent charge/discharge cycle characteristics, because a theoretically complicated chemical reaction does not occur at the time of the electrochemical reaction in the charging and discharging process. Use of carbon material as the electrode active material is a suggested method, as a solution for the problems of the cycle characteristics and the self-discharge characteristics of the electrode active material. Features of this carbon material are a high doping capacity, a low self-discharge rate and excellent cycle characteristics. A feature to be mentioned is that it has a base-potential extremely near to that of metallic lithium.
On the other hand, problem (2) is as described below. A
liquid electrolyte, especially one prepared by dissolving an ionic compound in an organic electrolyte, has so far been used for the electrolyte in a battery utilizing an electrochemical reaction, and in electrochemical devices other than a battery, such as an electric double-layer capacitor or an electrochromic element etc. However, since there have been troubles, such as leakage of electrolyte to the battery exterior, and easiness of elusion and evaporation of the electrode material etc. when a liquid electrolyte has been used, the problems of long-term reliability and dispersal of the electrolyte during the sealing process have remained unsolved. As a means to solve these problems, that is, a

-4-means to improve the solution-leakage resistance and the long-term reliability, an ion-conductive high-molecular compound having a large ionic conductivity has been reported and studied.
The ion-conductive high-molecular compounds being studied now are a straight-chain polymer, a network cross link polymer or a comb-shaped polymer of a homopolymer or copolymer having ethylene oxide as its basic unit. It is proposed and practised that crystallization is avoided by making the compound into the form of a network cross link polymer or a comb-shaped polymer for the purpose of increasing the ionic conductivity at a low temperature. Especially, an ion-conductive high-molecular compound using a network cross link polymer has a large mechanical strength and is excellent in ionic conductivity at a low temperature; so it is useful.
Electrochemical cells using an ion-conductive high-molecular compound are widely described in many patent documents. There are, for example, U.S. Patent No. 4,303,748 (1981) by Armand etc., U.S. Patent No. 4,589,197 (1986) by North, and U.S. Patent No. 4,547,440 (1985) by Hooper etc. A
feature that can be mentioned for these cells is the use of an ion-conductive high-molecular compound prepared by dissolving an ionic compound into a high-molecular compound having a polyether structure.
In order to use the ion-conductive high-molecular compound as the electrolyte for batteries utilizing an electrochemical reaction and for electrochemical devices other than a battery, it is required for the high-molecular compound

-5-to have both a high ionic conductivity and a good mechanical property (mechanical strength and flexibility etc.). However, these properties contradict each other. In many of the patent documents described above, for example, the compound is operated principally at a high temperature because the ionic conductivity at a temperature lower than room temperature decreases below a practical range. Therefore, as a simple method for improving the ionic conductivity, for example, a method has been proposed, in Published Patent Application (KOKAI) No. 59-149601, Published Patent Application (KOKAI) No. 58-75779, U.S. Patent No. 4,792,504 etc., that an organic solvent (specially preferably, an organic solvent with high permittivity) is added to the ion-conductive high-molecular compound to maintain the solid state. In this method, while the ionic conductivity is improved, the mechanical strength is worsened. In electrode active material utilizing the intercalation or doping phenomenon of the layer compound, expansion and contraction of the electrode active material are produced by charging and discharging. To cope with this problem, it is required to improve the mechanical strengths of the electrode and the electrolyte.
When an ion-conductive high-molecular compound is used as the electrolyte for electrochemical devices, it becomes necessary to make the electrolyte of film shape in order to reduce the internal resistance. This is especially important for a film type battery. In the case of an ion-conductive high-molecular compound, it is possible to work its uniform film easily into a voluntary shape, and various methods for

-6-this purpose are known. There are several methods, for example, such as a method in which a solution of the ion-conductive high-molecular compound is cast and its solvent is evaporated and removed; a method in which a polymeric monomer or macromer is applied onto a substrate to be heated and polymerized; or a method in which curing is carried out by irradiation. It is possible to obtain a uniform film when these methods are used. However, fine short-circuiting has sometimes occurred due to breakage of the electrolyte layer caused by its compression deformation when laminating the ion-conductive high-molecular compounds between the electrodes to assemble the battery or other electrochromic element.
Accordingly, in order to make the ion-conductive high-molecular compound into a uniform film, an improvement of the mechanical strength is important in addition to the ionic conductivity.
It has been found that the following problems arose when an ion-conductive high-molecular compound was used for a battery. In a secondary battery, gas was produced to cause an expansion in the battery when lithium metal was used for the electrode active material of the anode, and a passive film was formed on the anode when carbon material was used for the anode. These problems resulted in a worsening of the battery performance due to an increase in the battery internal impedance or a lowering of its long-term reliability or safety. Even in a primary battery, similar problems arose, because the water content was extracted from the electrode composite during long-term preservation.

These problems were attributable to the fact that the phenomena set out in the following (1) to (4) took place, because the materials used when manufacturing the ion-conductive high-molecular compound remained in the ion-s conductive high-molecular compound. A material, which is so prepared that a high-molecular compound having a reactive double-bond and a polyether structure is polymerized so as to have a cross link network structure, may be mentioned as the ion-conductive high-molecular compound. The high-molecular compound is generally prepared in such a way that an esterification reaction is carried out by using polyethylene glycol, acrylic acid or methacrylic acid, sulphuric acid or para-toluenesulfonic acid, and an organic solvent; and the prepared material is neutralized by using an alkali metal hydroxide and then washing using an alkali metal chloride aqueous solution. NaOH and KOH etc., for example, are used for the alkali-metal hydroxide; and NaCl, KCl, and LiCl etc., for example, are used for the alkali-metal chloride.
Multivalent ions, such as Caz+, Fez+, Cuz+, Ni3+, Fe3+, Co3+ and Cr3+ etc. are liable to mingle in water. For this reason, a sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid, methacrylic acid, Na+, K+, Ca2+, Fez*, CuZ+, Ni3+, Fe3+, Co3+ and Cr3+ etc . remain in the prepared ion-conductive high-molecular compound, and it was difficult to remove these ions.
(1) The water content is extracted from the electrode composite by repeated charge/discharge cycles. Together with the sulphate ion, para-toluenesulfonate ion, chlorine ion, and _8_ ethylene glycol etc. remaining in the ion-conductive high-molecular compound; this water content reaches the lithium metal forming the anode through the electrolyte comprising the ion-conductive high-molecular compound. These materials react with the lithium metal to produce hydrogen gas and the battery is expanded thereby.
(2) In the same way as in the foregoing (1); the sulphate ion, para-toluenesulfonate ion and polyethylene glycol etc.
reach the carbon material forming the anode, so that a passive film is formed on the surface of the carbon material.
(3) When acrylic acid or methacrylic acid remains in the high-molecular compound forming the material of the ion-conductive high-molecular compound and its residual quantity is large, the qualitative stability of the high-molecular compound is lowered and this compound is polymerized freely before manufacturing the ion-conductive high-molecular compound, so that the yield, the qualitative stability and the uniformity of the ion-conductive high-molecular compound are lowered. When films comprising such an ion-conductive high-molecular compound are used and laminated between the electrodes, the films can be broken due to compression deformation to cause a fine short-circuit, when assembling the batteries or electrochromic elements.
(4) When the ion-conductive high-molecular compound includes ions other than those performing the ionic conduction, the ionic conductivity is lowered.
This invention is made in consideration of the above-mentioned problems, and an object of this invention is to _g_ provide a battery having one of the properties shown in the following (1) to (4), and to provide a method for manufacturing such a battery.
(1) In the case when lithium metal is used for the electrode active material of the anode, the expansion of the battery is prevented so that the battery performance, long-term reliability and safety are improved.
(2) In the case when carbon material is used for the anode, the formation of a passive film on the anode is prevented, so that the battery performance, long-term reliability and safety are improved.
(3) The qualitative stability of the ion-conductive high-molecular compound forming the composition material is improved, breakage of the film comprising the ion-conductive high-molecular compound due to its compression deformation can be prevented, and fine short-circuiting can be prevented.
(4) The ionic conductivity of the ion-conductive high-molecular compound is improved and the battery performance is made better.
A first aspect of the invention provides a battery including a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material, or an anode comprising an electrode active material; characterized in that the battery content of at least one kind of sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid, which are able to remain in the battery, is kept to 0.1 wt% or smaller.
In this first aspect of the invention, the production of hydrogen gas and the formation of a passive film in the anode are restricted, because the battery content of at least one kind of sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid, is controlled to 0.1 wt% or smaller. Consequently, the performance, long-term reliability and safety of the battery are improved.
A second aspect of the invention provides a battery having a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material, or an anode comprising an electrode active material, and allowing a lithium ion to perform the ionic conduction; characterized by a battery content of at least one kind of alkali metal ion, other than the lithium ion, and multivalent ion, which are able to remain in the battery, is kept to 0.1 wt% or smaller.
The ionic conductivity of the ion-conductive high-molecular compound is improved and the battery performance is made better because the percentage of the ion performing the ionic conduction, i.e. the ion other than the lithium ion, is 0.1 wt% or smaller.
A third aspect of the invention provides a battery including a cathode composite having an ion-conductive high molecular compound as its composition material, and electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material or an anode comprising an electrode active material; characterized in that a radical scavenger is included in the battery and its percentage is controlled to 0.1 wt% or smaller.
If the percentage of the radical scavenger in the battery is larger than 0.1 wt%, a hydroxyl group included in the radical scavenger has a bad influence on the battery characteristics, especially on the characteristics after long-term storage, so that the long-term reliability is worsened.
However, this worsening of the battery characteristics is restricted when the percentage of the radical scavenger is 0.1 wt% or smaller.
The ion-conductive high-molecular compound in the above is one that is prepared by polymerizing at least one kind of high-molecular compound shown in formula (I) and formula (II) while including at least one kind of ionic compound. The above-mentioned high-molecular compound is one that is prepared in such a way that an esterification reaction is carried out by using polyethylene glycol, acrylic acid or methacrylic acid, sulphuric acid or para-toluenesulfonic acid, and an organic solvent; and the prepared material is neutralized by using an alkali metal hydroxide and then washed by using an alkali metal chloride aqueous solution.

R O R

Rl-~C HZ C HZ O~C H2 C H 0~ C-C=C H2 ...(I) (R1, Rz and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m ? 1, n >_ 0 and n/m = 0 to 5.) ~ II I 5 II I s C HZ=C-C-fC H2 C HZ O~C H2 C H O~C-C=C H2 ...(II) (R4, RS and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s ? 3, t >_ 0 and t/s = 0 to 5.) A high-molecular compound shown by formula (VII) may be used.
0-EC HZ C H2 0~-~-D1 I
--TN=P
I
O-f C H2 C H2 O~D2 ...(VII) (h and g represent an integer of h >_ 1 and g >- 1, and D1 and DZ
represent any one of the groups shown by formula (VIII), formula (IX) and formula (X).) I .(VIII) -C=C H2 ..
(R~ represents a hydrogen group or a lower alkyl group having a carbon number of 1 or larger.) -C-C=CH2 ...(Ix) I I

(R$ represents a hydrogen group or a lower alkyl group having,a carbon number of 1 or larger.) -S i-0-S i-C=C HZ
I .(x) R9 R9 ..
(R9 and Rlo represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger.) Since such an ion-conductive high-molecular compound is a cross-linked polymer formed by an ether bond, it does not include an intermolecular hydrogen bond and becomes a structure with a low glass transition temperature. For this reason, migration of the dissolved ionic compound becomes extremely easy in such an ion-conductive high-molecular compound. The formula (I) represents a monoacrylate or a monomethacrylate of polyethylene glycol, and the formula (II) represents a diacrylate or dimethacrylate of polyethylene glycol.
In the above at least the cathode composite or anode composite may include a binder. Thereby, the mechanical strengths of the cathode composite and the anode composite can be significantly improved.
Na+ and K+ etc. may be mentioned as the alkali metal ion, and Caz+, Fez+, Cuz+, Ni3+, Fe3+, Co3+ and Cr'+ etc . may be mentioned as the multivalent ion.
At least one kind of a compound shown by formula (III), formula (IV), formula (V) and formula (VI) may be used for the radical scavenger.
H 0 O R11 .. . (III) (Rll represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) HO ~ ...(IV) (R1z represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) HO O ...(v) (R13 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) OH

...~~I) (Rla~ Rls and R16 represent a lower alkyl group or a lower alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) A fourth aspect of the invention provides a manufacturing method for a battery including a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material or an anode comprising an electrode active material;
characterized in that at least one kind of a high-molecular compound shown by formula (I) and formula (II) is used, the high-molecular compound is polymerized to manufacture an ion-conductive high-molecular compound including at least one kind of ionic compound, and a radical scavenger has already been included in the foregoing high-molecular compound.

R 1~C H~ C H2 0 m-f C H2 C H 0~ C-C=C HZ
...(I) (R1, Rz and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m >_ 1, n >- 0 and n/m = 0 to 5.) i II I II
C HZ=C-C--EC HZ C HZ 0~-s--EC HZ C H O~C-C=C H2 ...(II) (R4, RS and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s >_ 3, t >- 0 and t/s = 0 to 5.) The radical scavenger functions as a stabilizer for the high-molecular compound. If the radical scavenger is not included, the high-molecular compound polymerizes freely before preparing the ion-conductive high-molecular compound by polymerization. This degree of polymerization is smaller than the degree of polymerization of a ion-conductive high-molecular compound prepared by polymerization. Therefore, the quality of the prepared ion-conductive high-molecular compound becomes unstable, so that the desired quality is not obtainable. Since the radical scavenger has been previously included in the high-molecular compound, the free polymerization of the high-molecular compound can be restricted and the quality of the prepared ion-conductive high-molecular compound, i.e. the quality of the battery can be made stable.

It is preferable to control the content of the radical scavenger in the battery down to 0.1 wt% or smaller. The reason is that the hydroxyl group included in the radical scavenger would have a bad influence on the battery characteristics, especially on the characteristics after long-term storage, and a battery with low long-term reliability would be produced, if the amount of the radical scavenger were larger than 0.1 wt%. Compounds shown in the above formula (III) to formula (VI) may be mentioned as the radical scavenger.
As the ionic compound, inorganic ionic salts including one kind of Li, Na or K, such as LiCl04, LiBF4, LiAsFs, LiPFs, LiI, Liar, LiZBloCllo, LiCF3S03, LiCF3C02, LiSCN, NaI, NaSCN, NaBr, NaC104, KC104, and KSCN etc.; quaternary ammonium salts such as ( CH3 ) 4NBF4, ( CH3 ) 4NBr, ( CZHS ) 4NC104, ( CzHS ) 4NI , ( C3Ii~ ) 4NBr, ( n-C4H9 ) 4NC104, ( n-C4H9 ) 4NI , ( CZHS ) 4N-maleate, ( CZHS ) aN-benzoate and (CZHS)4N-phthalate etc.; and organic ionic salts, such as lithium stearyl sulphonate, sodium octyl sulphonate and lithium dodecylbenzene sulphonate etc.; for example, may be mentioned. Two or more kinds of these ionic compounds may be combined.
Concerning the mixing ratio of these ionic compounds, the ratio of the ionic compound to the foregoing high-molecular compound is 0.0001 to 5.0 mol/.2, especially a ratio of 0.005 to 2.0 mol/.2 is preferable. If the quantity of the ionic compound is excessive, the excess ionic compound, i.e. the inorganic ionic salt for example, does not dissociate, but is only present as a mixture, resulting in a decrease of the -lg_ ionic conductivity. Further, the proper mixing ratio of the ionic compound differs depending on the electrode active material. For example, a ratio around a value offering the maximum ion conductivity of the electrolyte is preferable for a battery utilizing the intercalation of a layer compound, and the ratio must be set so as to correspond to the change of ion concentration in the electrolyte caused by charging and discharging for a battery using an electro-conductive polymer utilizing the doping phenomenon as the electrode active material.
There is no special limitation on the method of inclusion of the ionic compound. A method may be mentioned, for example, in which the ionic compound is dissolved in an organic solvent, such as methylethylketone or tetrahydrofuran etc. and mixed uniformly with the foregoing high-molecular compound, the organic solvent then being removed under vacuum reduced pressure.
An organic compound that can dissolve the ionic compound may be included in the foregoing ion-conductive high-molecular compound. By doing so, the ionic conductivity can be markedly improved without changing the basic skeleton of the ion-conductive high-molecular compound.
As the organic compoumd that can dissolve the ionic compound; a cyclic carbonic ester, such as propylene carbonate and ethylene carbonate etc.; cyclic esters, such as Y-butyro-lactone etc.; ethers, such as tetrahydrofuran or its derivative, 1,3-dioxane, 1,2-dimethoxyethane and methyldigraim etc.; nitriles such as acetonitrile and benzonitrile etc.;

_19- 21 18401 dioxorane or its derivative; and sulfolane or its derivative etc.; for example, may be mentioned. These compounds may be used independently or combined. The kind of material is not limited to them. The mixing ratio and the mixing method are at will.
A binder may be included as a composition material in at least one of the cathode composite and the anode composite.
By doing so, the mechanical strengths of the cathode composite and anode composite are markedly improved.
As the binder, a polymer of high molecular weight ethylene oxide and a random copolymer of high molecular weight ethylene oxide-propylene oxide, etc. may be mentioned. It is preferable that the composition ratio (the mole ratio) of ethylene oxide unit (EO) and propylene oxide unit (PO) in the random copolymer of high molecular weight, ethylene oxide-propylene oxide is in the range of 0 < (PO)/(EO) <_ 5.
However, the ratio is not limited to this range.
The binder is prepared by dissolving or dispersing an organic compound, which will be described later, in a solvent, such as dimethylformamide or xylene etc., for example. As the organic compound, a polymer or copolymer of the following compounds may be mentioned. As the compounds; acrylonitrile, methacrylonitrile, vinylidene fluoride, vinyl fluoride, chloroprene, vinyl piridine or its derivative, vinylidene chloride, ethylene, propylene, cyclic diene etc., may be mentioned. As the cyclic diene; cyclopentadiene, 1,3-cyclohexadiene etc., for example, may be mentioned.

As methods for including the binder into the cathode composite and anode composite; a method in which the foregoing organic compound is dissolved in a solvent, the electrode active material and the ion-conductive high-molecular compound etc. are dispersed in it, and the prepared solution is used as an application liquid; and a method in which the electrode active material and the ion-conductive high-molecular compound etc. are dispersed in a dispersant liquid comprising the foregoing organic compound and a dispersant for dispersing the organic compound, the prepared solution being used as an application liquid etc., are generally used.
Carbon material may be used as the negative active material for the anode composite. Carbon material has a high doping capacity, a low self-discharge rate, excellent cycle characteristics, and a base-potential extremely near to that of metallic lithium. Theoretically, it does not produce a complicated chemical reaction during charging and discharging.
Consequently, excellent charge/discharge cycle characteristics can be obtained when carbon material is used as the negative active material for the anode composite. In addition, the anode composite becomes very stable from the physical and electrochemical points of view.
As the negative active material, alloys including lithium metals, such as lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium and Wood's alloys etc., lithium metals and carbon materials etc., may be mentioned.
These materials may be used in combination.

As the carbon material; it is preferable to use materials having results analyzed by X-ray diffraction as listed in Table 1, carbon powder prepared by burning anisotropic pitch at a temperature of 2,000°C or more (average grain size: 15 Nm or smaller), and carbon fiber etc., for example.
[Table 1]
Lattice spacing (d002) 3.35 ~' 3.40 Size of crystalline in a-axis direction La: 200 ~ or more Size of crystalline in c-axis direction Lc: 200 ~ or more True density 2.00 ~' 2.25 g/cm3 As the positive active material for use in the cathode composite, the following materials may be mentioned. There are I-group metallic compounds, such as CuO, CuZO, AgzO, CuS
and CuS04 etc.; IV-group metallic compounds, such as TiS2, SiOz and Sn0 etc.; V-group metallic compounds, such as Vz05, V6O12, VOx, Nbz05, BiZ03 and Sbz03 etc . ; VI-group metallic compounds, such as Cr03, Crz03, MoS2, W03 and SeZOZ, etc . ; VI I-group metallic compounds, such as Mn02 and Mn203 etc.; VIII-group metallic compounds, such as Fez03, FeO, Fe304, Ni203, NiO, CoSz and Co0 etc.; metallic compounds such as a lithium-cobalt composite oxide and a lithium-manganese composite oxide etc., for example, expressed by the general formulas of LixMX2 and LiXMNyX2 (M and N being I- through VIII-group metals and X
being chalcogens compound, such as oxygen and sulfur etc.);

-22- 2 ~ ~ 8 4 0 electro-conductive high-molecular compounds, such as polypyrrole, polyaniline, polyparaphenylene, polyacetylene and polyacene group materials; and pseudo-graphite structural carbon material etc. However, the kind of positive active material is not limited to these compounds.
Concerning the installation method of the ion-conductive high-molecular compound on the surfaces of the cathode composite and the anode composite; it is preferable to apply the compound with a uniform thickness by means of, for example, a coating roller, a doctor blade, a spin coating or a bar coder etc. However, the kind of installation method is not limited to these examples. By using such means, it becomes possible to apply the foregoing ion-conductive high-molecular compound on the surfaces of the cathode composite and the anode composite in a voluntary thickness and with a voluntary shape.
Concerning the installation method of the cathode composite and the anode composite on the positive current collector plate and the negative current collector plate respectively, it is preferable to apply the composite with a uniform thickness by means of, for example, an applicator roll, a doctor blade, a spin coating or a bar coder etc.
However, the kind of installation method is not limited to these. By using such means, it becomes possible to increase the practical surface areas of the electrode active material in contact with the electrolytes and current collector plates in the cathode composite and the anode composite, and it becomes possible to apply the cathode composite and the anode composite on the positive current collector plate and the negative current collector plate in a voluntary thickness and with a voluntary shape. In these cases, carbon such as graphite, carbon black and acetylene black etc. (this carbon has properties quite different from the carbon used for the negative active material), and electro-conductive material, such as metallic powder, and electro-conductive metal oxide etc. are mixed in the cathode composite and the anode composite as occasion demands, so that the electron conductivity can be improved. Further, in order to obtain an uniformly mixed and dispersed system when manufacturing the cathode composite and the anode composite, several kinds of dispersants and dispersion mediums may be added. In addition, a thickener, an extender and a tackifier may be added.
It is preferable to use aluminum, stainless steel, titanium or copper etc. for the positive current collector plate and to use stainless steel, iron, nickel or copper etc.
for the negative current collector plate. However, the kind of material is not limited to these examples.
In accordance with one aspect of the present invention there is provided a battery containing: (A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material; (B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode comprising a composite having an ion-conductive high-molecular compound and a negative active material;
characterized in that the concentration, contained in the battery, of sulphate ion, para-toluenesulfonate ion, chlorine -23a-ion, polyethylene glycol, acrylic acid and methacrylic acid is limited to 0.1 wt~ or less.
In accordance with another aspect of the present invention there is provided a battery containing: (A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material; (B) an electrolyte being composed of the in-conductive high-molecular compound;
and (C) an anode composed of a negative active material;
characterized in that the concentration, contained in the battery, of sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid is limited to 0.1 wte or less.
In accordance with yet another aspect of the present invention there is provided a battery containing: (A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material; (B) an electrolyte being composed of the in-conductive high-molecular compound;
and (C) an anode comprising a composite having an ion-conductive high-molecular compound and a negative active material; characterized in that the concentration, contained in the battery, of a multivalent ion and an alkali metal ion, other than lithium ion, is limited to 0.1 wt~ or less.
In accordance with still yet another aspect of the present invention there is provided a battery containing: (A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material; (B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode composed of a negative active -23b-material and allowing ionic conduction performed by lithium ion; characterized in that the concentration, contained in the battery, of a multivalent ion and an alkali metal ion, other than lithium ion, is limited to 0.1 wt% or less.
In accordance with still yet another aspect of the present invention there is provided a battery having in its interior a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material; characterized in that a radical scavenger is included in the battery and its content is controlled to 0.1 wt~ or smaller.
In accordance with still yet another aspect of the present invention there is provided a battery having in its interior a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode comprising an electrode active material; characterized in that a radical scavenger is included in the battery and its content is controlled to 0.1 wt% or smaller.
In accordance with still yet another aspect of the present invention there is provided a manufacturing method for a battery containing a cathode composite comprising an ion-conductive high-molecular compound and a positive active material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition -23c-material; characterized in that at least one kind of high-molecular compound shown by formula (I) and formula (II) is used, the high-molecular compound is polymerized to manufacture an ion-conductive high-molecular compound while including at least one kind of ionic compounds, and a radical scavenger is included in said high-molecular compound, R O R.

Rl--EC H2 C H2 O~C H2. C H 0~ C-C=C H2 .. _ (I) to (R1, R2 and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m Z 1, n >- 0 and n/m = 0 to 5.) C HZ=C-C-EC HZ C H2 0~-~--~C H2 C H O~C-C=C H

. . . (II) (R9, R5 and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s Z 3, t >- 0 and t/s = 0 to 5).
In accordance with still yet another aspect of the present invention there is provided a manufacturing method for a battery containing a cathode composite having an ion-conductive high-molecular compound and a positive active material, an electrolyte comprising the ion-conductive high--23d-molecular compound, and an anode comprising an electrode active material; characterized in that at least one kind of high-molecular compound shown by formula (I) and formula (II) is used, the high-molecular compound is polymerized to manufacture an ion-conductive high-molecular compound while including at least one kind of ionic compounds, and a radical scavenger is included in said high-molecular compound, R 0 R.

R1~C HZ C HZ O~C H2 C H O n C-C=C HZ ... (I) (Rl, R2 and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m ~ 1, n >- 0 and n/m = 0 to 5.) R O R O R

I li 1 CHZ+=C-C-EC H2 CH2 O~-~--ECH2.CHO~C-C=CHZ
. . . (II) (R4, R5 and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s Z 3, t >- 0 and t/s = 0 to 5).

-23e-In the Drawings:
Fig. 1 is a vertical sectional view showing a film type primary battery which is an example of a battery of this invention;
Fig. 2 is a diagram showing the discharge characteristics at the initial stage and the discharge characteristics after long-term storage for the respective batteries of embodiments 1 and 2 and comparison example 1;

Fig. 3 is a diagram showing the relation in a primary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C, and the content of sulphate ion and chlorine ion;
Fig. 4 is a diagram showing the charge/discharge cycle characteristics at the initial stage and charge/discharge cycle characteristics after long-term storage for the respective batteries of embodiments 3 and 4 and comparison example 2;
Fig. 5 is a diagram showing the discharge characteristics at the initial stage and the discharge characteristics after long-term storage for the respective batteries of embodiment 5 and comparison example 3;
Fig. 6 is a diagram showing the relation in a primary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C and the content of polyethylene glycol;
Fig. 7 is a diagram showing the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage for the respective batteries of embodiment 6 and comparison example 4;
Fig. 8 is a diagram showing the relation in a secondary battery between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of polyethylene glycol;
Fig. 9 is a diagram showing the discharge characteristics at the initial stage and the discharge characteristics after long-term storage for the respective batteries of embodiment 7 and comparison example 5;
Fig. 10 is a diagram showing the relation in a primary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C and the content of acrylic acid;
Fig. 11 is a diagram showing the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage for the respective batteries of embodiment 8 and comparison example 6;
Fig. 12 is a diagram showing the relation in a secondary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C and the content of acrylic acid;
Fig. 13 is a diagram showing the discharge characteristics at the initial stage and the discharge characteristics after long-term storage for the respective batteries of embodiment 9 and comparison example 7;
Fig. 14 is a diagram showing the relation in a primary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C and the content of alkali metal ion or multivalent ion;
Fig. 15 is a diagram showing the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage for the respective batteries of embodiment 10 and comparison example 8:

'~ 21 18401 Fig. 16 is a diagram showing the relation in a secondary battery between the rising rate of internal impedance of the battery after storage for 100 days at 60°C and the content of alkali metal ion or multivalent ion;
Fig. 17 is a diagram showing the discharge characteristics at the initial stage and the discharge characteristics after long-term storage for the respective batteries of embodiment 11 and comparison example 9; and Fig. 18 is a diagram showing the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage for the respective batteries of embodiment 12 and comparison example 10.
(Embodiment 1) Fig. 1 is a vertical sectional view showing a film type primary battery, which is an example of this invention. In this figure, 1 is a positive current collector plate, 2 is a cathode composite, 3 is an electrolyte layer, 4 is an anode, 5 is a negative current collector plate and 6 is a sealing material comprising denatured polypropylene. The current collector plates 1 and 5 also serve as outer package members.
In this battery the cathode composite 2 is composed of a positive active material, a conductive material, an ion-conductive high-molecular compound and a binder. The anode 4 is composed of a negative active material. The electrolyte layer 3 is composed of an ion-conductive high-molecular compound.

A battery of this embodiment was made by the following processes (a) to (d).
(a) The cathode composite 2 was formed in the following manner. Mn02 forming the positive active material was mixed with acetylene black forming the conductive material, with a weight ratio of 85 to 15 (mixture A1), the mixture A1 was mixed with a xylene solution (2 wt% solution) of a copolymer of ethylene-propylene-1,3-cyclohexadiene forming the binder with a weight ratio of 2.2 to 2 under an atmosphere of dried inert gas (mixture B1).
10 weight parts of a high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 4 to 6, were mixed with 1 weight part of LiC104 and 20 weight parts of propylene carbonate (mixture C1). The mixture B1 was mixed with the mixture C1 with a weight ratio of 10 to 3 under an atmosphere of dried inert gas (mixture D1). This mixture D1 was cast by means of screen coating on the positive current collector plate 1 comprising stainless steel, on the surface of which a conductive carbon film was formed, and was irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured.
The film thickness of the cathode composite 2 formed on the positive current collector plate 1 was 60 Nm.

C H3--f C H~ C HZ O~C-C=C H2 ...(XI) I II I
C H2= C-C-f-C H2 C~H2 O~C-C=C H2 Ck= 1 0 0~~1 1 0) ...(XII) (b) The electrolyte layer 3 was formed on the cathode composite 2 in the following manner. 30 Weight parts of a high-molecular mixture the same as in process (a) were mixed with 6 weight parts of LiClOd and 64 weight parts of propylene carbonate (mixture E1). This mixture E1 was cast by means of screen coating on the cathode composite 2, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The thickness of the electrolyte layer 3 formed on the cathode composite 2 was 25 um.
In processes (a) and (b), the high-molecular compounds of formulas (XI) and (XII) were prepared in such a way that an esterification reaction was carried out by using polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst, and an organic solvent; and the prepared material was neutralized by using an alkali metal hydroxide and then washed by using NaCl aqueous solution.
(c) The anode 4 was composed of lithium metal forming the negative active material, and was formed by being press bonded to the negative current collector plate 5 of stainless steel.
(d) A laminate of the electrolyte layer 3, the cathode composite 2 and the positive current collector plate 1 prepared by the process (b), and a laminate of the anode 4 and the negative current collector plate 5 prepared by the process (c), were brought into contact with each other at the electrolyte layer 3 and the anode 4. Thereby, the battery shown in Fig. 1 was prepared.
In the battery of this embodiment, the respective contents of the sulphate ion and the chlorine ion in the battery were as follows;
sulphate ion... 0.0280 wt%
chlorine ion... 0.0250 wt%
In order to set the contents as above when the high-molecular compounds of formulas (XI) and (XII) were prepared, neutralization was conducted strictly, and washing was proceeded with as small a quantity as possible of the NaCl aqueous solution.
The contents of the sulphate ion and the chlorine ion were measured in the following manner. The battery was subjected to a centrifugation process and an extraction process at the same time as manufacture of the battery.
Thereafter, each of the mixture D1 and the mixture El were measured quantitatively by means of ion chromatography and an ICP-AES emission spectrochemical analysis method. The measured values thus obtained were converted to that of the battery interior. The battery interior of this embodiment is composed of the cathode composite 2, the electrolyte layer 3 and the anode 4.
(Embodiment 2) This embodiment is different from embodiment 1 only on the following point. In this embodiment, para-toluenesulfonic acid was used as an acid catalyst when the high-molecular compounds of formulas (XI) and (XII) were prepared.
In the battery of this embodiment, the respective contents of the para-toluenesulfonate ion and the chlorine ion in the battery were as follows;
- para-toluenesulfonate ion... 0.0210 wt%
chlorine ion... 0.0240 wt%
The manner of setting the contents as above and measuring the contents are the same as in embodiment 1.
(Comparison example 1) A battery of this comparison example is different from that of embodiment 1 only on the following point. In the battery of this comparison example, the respective contents of the sulphate ion and the chlorine ion in the battery were as follows;
sulphate ion... 0.2250 wt%
chlorine ion... 0.1820 wt%
(Test 1) Discharge tests were done on the batteries of embodiments 1 and 2 and comparison example 1 to examine the respective discharge characteristics at the initial stage (just after manufacture of the battery) and the respective discharge characteristics after long-term storage. The electrode surface area could be changed variously depending on the manufacturing process. However, it was set to 100 cmz in these tests.
The conditions of the discharge tests were a temperature of 25°C, and a load of 3 kS~.

The period of long-term storage was 100 days at 60°C.
Fig. 2 shows the discharge characteristics at the initial stage and after long-term storage. In the figure, X1(i) and X2(i) indicate the respective discharge characteristics at the initial stage of the batteries of embodiments 1 and 2, X1(p) and X2(p) indicate the respective discharge characteristics after long-term storage of the batteries of embodiments 1 and 2, Y1(i) indicates the discharge characteristics at the initial stage of the battery of comparison example 1 and Y1(p) indicates the discharge characteristics after long-term storage of the battery of comparison example 1. Further, the abscissa represents the discharge time (hour) and the ordinate represents the discharge voltage (V).
As is obvious from Fig. 2, the batteries of embodiments 1 and 2 are excellent both in their discharge characteristics at the initial stage and after long-term storage as compared with the battery of comparison example 1.
40 cells of the batteries of embodiments 1 and 2 and comparison example 1 were examined to check the number of expanded cells after long-term storage. The number was zero for the batteries of embodiments 1 and 2, but it was three for the battery of comparison example 1. In other words, no expansion was observed in the batteries of embodiments 1 and 2.
Further, the relation between the rising rate of internal impedance of the battery after storage for 100 days at 60°C, and both the contents of the sulphate ion and the chlorine ion were examined. Fig. 3 shows the results. In Fig. 3, Ia indicates the internal impedance of the battery before storage, and Ib indicates the internal impedance of the battery after storage. The rising rate is calculated by (Ib - Ia)~Ia x 100(%). As shown in Fig. 3, the rising rate of the internal impedance changes largely at a border point where both the contents of the sulphate ion and the chlorine ion are about 0.1 wt%. The rising rate is extremely small at 0.1 wt%
or less. That is, when the contents of both these ions are 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of the internal impedance is restrained.
(Embodiment 3) This embodiment relates to a film type secondary battery that is an example of this invention. The fundamental structure of the battery is the same within the battery of Fig. l, except that 4 is an anode composite.
In this battery the cathode composite 2 is composed of a positive active material, a conductive material, an ion-conductive high-molecular compound and a binder. The anode composite 4 is composed of a negative active material, an ion-conductive high-molecular compound and a binder. The electrolyte layer 3 is composed of an ion-conductive high-molecular compound.
The battery of this embodiment was made by the following processes (a) to (e).
(a) The cathode composite 2 was formed in the following manner. LiCoOz forming the positive active material was mixed with acetylene black forming the conductive material with a weight ratio of 85 to 15 (mixture A3), the mixture A3 was mixed '~ 21 18401 with dimethylformamide solution (2 wt% solution) of polyacrylonitrile forming the binder with a weight ratio of 2.4 to 2 under an atmosphere of dried inert gas (mixture B3).
weight parts of high-molecular mixture prepared by 5 mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.5 to 6.5, were mixed with 0.02 weight part of principal-chain straight-chain type polyethylene oxide, 1 weight part of LiBF4, 10 weight parts of 1,2-dimethoxyethane and 10 weight 10 parts of ~-butyrolactone (mixture C3). The mixture B3 was mixed with the mixture C3 with a weight ratio of 10 to 3 under an atmosphere of dried inert gas (mixture D3). This mixture D3 was cast by means of screen coating on the positive current collector plate 1 comprising aluminum, on a surface of which a conductive carbon film was formed, and irradiated with an electron beam having an intensity of 12 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the cathode composite 2 formed on the positive current collector plate 1 was 60 Nm.
(b) The electrolyte layer 3 was formed on the cathode composite 2 in the following manner. 30 weight parts of the same high-molecular mixture as in process (a) were mixed with 0.06 weight part of a principal-chain straight-chain type polyethylene oxide, 6 weight parts of LiBF4, 32 weight parts of 1,2-dimethoxyethane and 32 weight parts of y-butyrolactone (mixture E3). This mixture E3 was cast by means of screen coating on the cathode composite 2 under an atmosphere of dried inert gas, and irradiated with an electron beam having '''~ 21 18 4 01 an intensity of 8 Mrad under an atmosphere of a dried inert gas, so as to be cured. The film thickness of the electrolyte layer 3 formed on the cathode composite 2 was 25 Nm.
(c) The anode composite 4 was formed in the following manner.
Carbon powder forming the negative active material was mixed with a xylene solution (2 wt% solution) of a copolymer of ethylene-propylene-cyclopentadiene forming the binder with a weight ratio of 2 to 5 under an atmosphere of dried inert gas (mixture F3). 10 weight parts of high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.2 to 6.8, were mixed with 1 weight part of LiBFd, 10 weight parts of 1,2-dimethoxyethane and 10 weight parts of y-butyrolactone (mixture G3). This mixture F3 was mixed with the mixture G3 with a weight ratio of 8 to 2 under an atmosphere of dried inert gas (mixture H3). This mixture H3 was cast by means of screen coating on the negative current collector plate 5 comprising stainless steel, and irradiated with an electron beam having an intensity of 12 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the anode composite 4 formed on the negative current collector plate 5 was 30 Nm.
(d) The electrolyte layer 3 was formed on the anode composite 4 in the following manner. The mixture E3, the same as in process (b), was prepared. This mixture E3 was cast by means of screen coating on the anode composite 4 under an atmosphere of dried inert gas, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the electrolyte layer 3 formed on the anode composite 4 was 25 Nm.
In processes (a) to (d), the manufacturing method for the high-molecular compounds of formulas (XI) and (XII) and the apparatus for the manufacture were the same as in embodiment 1. That is, the high-molecular compounds of formulas (XI) and {XII) were prepared in such a way that an esterification reaction was carried out by using polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst, and an organic solvent; and the prepared material was neutralized by using an alkali metal hydroxide and then washed by using a NaCl aqueous solution. And, in this embodiment, when the high-molecular compounds of formulas (XI) and (XII) were prepared, neutralization was carried out strictly, and washing was proceeded with as small a quantity as possible of NaCl aqueous solution.
(e) A laminate of the electrolyte layer 3, the cathode composite 2 and the positive current collector plate 1 prepared by process (b) and a laminate of the electrolyte layer 3, the anode composite 4 and the negative current collector plate 5 prepared by process (d) were placed in contact with each other at the respective electrolyte layers 3.
In the battery of this embodiment, the respective contents of the sulphate ion and the chlorine ion in the battery were as follows;
sulphate ion... 0.0300 wt%
chlorine ion... 0.0220 wt%

The contents of the sulphate ion and the chlorine ion were measured in the same manner as in embodiment 1. That is, the battery was subjected to a centrifugation process and an extraction process after manufacture. Thereafter, each of the mixture D3, the mixture E3 and the mixture H3 was measured quantitatively by means of ion chromatography and ICP-AES
emission spectrochemfcal analysis method. The measured values thus obtained were converted to that of the battery interior.
The battery interior of this embodiment is composed of the cathode composite 2, the electrolyte layer 3, and the anode composite 4.
(Embodiment 4) This embodiment is different from embodiment 3 only in the following point. In this embodiment, para-toluenesulfonic acid was used as an acid catalyst when the high-molecular compounds of formulas (XI) and (XII) were prepared.
In the battery of this embodiment, the respective contents of the para-toluenesulfonate ion and the chlorine ion in the battery were as follows;
~ para-toluenesulfonate ion... 0.0260 wt%
chlorine ion... 0.0240 wt%
The manner of setting the contents as above and measuring the contents are the same as in embodiment 3.
(Comparison example 2) A battery of this comparison example is different from that of embodiment 3 only in the following point.

--In the battery of this comparison example, the respective contents of the sulphate ion and the chlorine ion in the battery were as follows;
sulphate ion... 0.2330 wt$
~ chlorine ion... 0.1890 wt%
(Test 2) Charge/discharge cycle tests were done on the batteries of embodiments 3 and 4 and comparison example 2 to examine the respective charge/discharge cycle characteristics at the initial stage (just after manufacture of the battery) and the respective charge/discharge cycle characteristics after long-term storage. The electrode surface area could be changed variously depending on the manufacturing process. However, it was set to 100 cm2 in these tests.
~ The conditions of the charge/discharge cycle test were a temperature of 25°C, a constant-current constant-voltage charge of 50 NA/cm2, a constant-current discharge of 50 uA/cm2, a charge end voltage of 4.1 V and a discharge end voltage of 2.7 V.
~ The period of long-term storage was 100 days at 60°C.
Fig. 4 shows the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage. In the figure, X3(i) and X4(i) indicate respective charge/discharge cycle characteristics at the initial stage of the batteries of embodiments 3 and 4, X3(p) and X4(p) indicate the respective charge/discharge cycle characteristics after long-term storage of the batteries of embodiments 3 and 4, Y2(i) indicates a charge/discharge cycle characteristic at the initial stage of the battery of comparison example 2, and Y2(p) indicates a charge/discharge cycle characteristic after long-term storage of the battery of comparison example 2. Further, the abscissa represents the number of times of the charge/discharge cycle and the ordinate represents the battery capacity (mAh).
As is obvious from Fig. 4, the batteries of embodiments 3 and 4 are excellent both in their charge/discharge cycle characteristics at the initial stage and their charge/discharge cycle characteristics after long-term storage as compared with the battery of comparison example 2.
30 Cells of the batteries of embodiments 3 and 4 and comparison example 2 were examined to check the number of expanded cells after long-term storage. The number was zero for the batteries of embodiments 3 and 4, but it was five for the battery of comparison example 2. In other words, no expansion was observed in the case of the batteries of embodiments 3 and 4.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and both the contents of the sulphate ion and the chlorine ion were examined. When both the contents of the sulphate ion and the chlorine ion were 0.1 wt% or less, the rising rate was extremely small.
(Embodiment 5) This embodiment is different from embodiment 1 only in the following point.

°

'1 21 18401 In the battery of this embodiment, the content of the polyethylene glycol in the battery was 0.0290 wt%. In this embodiment, in order to set the content as above, when the high-molecular compounds of formulas (XI) and (XII) were prepared, a somewhat excessive quantity of acrylic acid was used so that the polyethylene glycol would fully react. The content of polyethylene glycol was measured in the following manner.
The battery was subjected to a centrifugation process and the extraction process at the time of manufacture.
Thereafter, each of the mixtures before casting was measured quantitatively by means of liquid chromatography and titration analysis of hydrolysis reaction. The titration analysis was carried out by titrating excessive acetic acid with KOH after acetylation with acetylation reagent (acetic anhydride-pyridine).
(Comparison example 3) A battery of this comparison example is different from that of the embodiment 5 only in the following point. In the battery of this comparison example, the content of polyethylene glycol was 0.1720 wt%.
(Test 3) Discharge tests were performed on the batteries of embodiment 5 and comparison example 3 in the same manner as test 1 to examine the respective discharge characteristics at the initial stage and the respective discharge characteristics after long-term storage.

Fig. 5 shows the discharge characteristics at the initial stage and after long-term storage. In the figure, X5(i) indicates the discharge characteristics at the initial stage of the battery of the embodiment 5, X5(p) indicates the discharge characteristics after long-term storage of the battery of embodiment 5, Y3(i) indicates the discharge characteristics at the initial stage of the battery of comparison example 3, and Y3(p) indicates the discharge characteristics after long-term storage of the battery of comparison example 3. Further, the abscissa represents the discharge time (hour) and the ordinate represents the discharge voltage (V).
As is obvious from Fig. 5, the battery of embodiment 5 is excellent both in its discharge characteristics at initial stage and the discharge characteristics after long-term storage as compared with the battery of comparison example 3.
Further, 40 cells of the batteries of embodiment 5 and comparison example 3 were examined to check the fraction defective after manufacture. The number of defectives was zero for the battery of embodiment 5, but it was six for the battery of comparison example 3. In other words, no defect was recognized in the case of the battery of embodiment 5.
This may be attributable to a fact that, in the battery of comparison example 3, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular compounds of formulas (XI) and (XII) were naturally polymerized to be formed into a thin film that was weak in mechanical strength, so that fine short-circuiting occurred easily.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of polyethylene glycol was examined.
Fig. 6 shows the result. In Fig. 6, Ia, Ib and the rising rate indicate the same as in Fig. 3. As shown in Fig. 6, the rising rate of the internal impedance of the battery changes largely at a border point where the content of polyethylene glycol is about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less. That is, when the content of polyethylene glycol was 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of its internal impedance was restrained.
(Embodiment 6) This embodiment is different from embodiment 3 only in the following point. In the battery of this embodiment, the content of polyethylene glycol in the battery was 0.0280 wt%.
The apparatus for setting the content as above and the manner of measuring the content of polyethylene glycol are the same as in embodiment 5.
(Comparison example 4) The battery of this comparison example was different from that of embodiment 6 only in the following point. In the battery of this comparison example, the content of polyethylene glycol in the battery was 0.1620 wt%.
(Test 4) Charge/discharge cycle tests were carried out on the batteries of embodiment 6 and comparison example 4 in the same manner as in test 2 to examine the respective charge/discharge cycle characteristics at the initial stage and after long-term storage.
Fig. 7 shows the charge/discharge cycle characteristics at the initial stage and the charge/discharge cycle characteristics after long-term storage. In the figure, X6(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of embodiment 6, X6(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of embodiment 6, Y4(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of comparison example 4, and Y4(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of comparison example 4. Further, the abscissa represents the number of charge/discharge cycles (time), and the ordinate represents the battery capacity (mAh).
As is obvious from Fig. 7, the battery of embodiment 6 is excellent both in its charge/discharge cycle characteristics at the initial stage and after long-term storage as compared with the battery of comparison example 4.
Further, 30 cells of the batteries of embodiment 6 and comparison example 4 were examined to check the fraction defective after manufacture. The number of defects was zero for the battery of embodiment 6, but it was four for the battery of comparison example 4. In other words, no defect was observed in the case of the battery of embodiment 6. This may '" 21 18401 be attributable to the fact that, in the battery of comparison example 4, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular compounds of formulas (XI) and (XII) were naturally polymerized to be formed into a thin film that is weak in mechanical strength, so that fine short-circuiting occurred easily.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of polyethylene glycol was examined.
Fig. 8 shows the result. In Fig. 8, Ia, Ib and the rising rate are the same as in Fig. 3. As shown in Fig. 8, the rising rate of the internal impedance changes largely at a border point where the content of polyethylene glycol is about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less.
That is, when the content of the polyethylene glycol was 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of internal impedance was restrained.
(Embodiment 7) This embodiment is different from embodiment 1 only in the following point.
In the battery of this embodiment, the content of acrylic acid in the battery was 0.0190 wt%. In this embodiment, in order to set the content as above, when the high-molecular compounds of formulas (XI) and (XII) were prepared, the quantity of polyethylene glycol was slightly exceeded so that the acrylic acid would react fully. The content of acrylic acid was measured in the following manner. The battery was subjected to a centrifugation process and an extraction process at the time of manufacture. Thereafter, each of the mixtures before casting was measured quantitatively by means of liquid chromatography and titration analysis. The titration analysis was carried out by titrating with a KOH-ethanol solution, for example, using Bromothymol Blue as an indicator.
(Comparison example 5) A battery of this comparison example is different from that of embodiment 7 only in the following point. In the battery of this comparison example, the content of acrylic acid in the battery was 0.1220 wt%.
(Test 5) Discharge tests were performed on the batteries of embodiment 7 and the comparison example 5 in the same manner as in test 1 to examine the respective discharge characteristics at the initial stage and after long-term storage.
Fig. 9 shows the discharge characteristics at the initial stage and after long-term storage. In the figure, X7(i) indicates the discharge characteristics at the initial stage of a battery of embodiment 7, X7(p) indicates the discharge characteristics after long-term storage of the same battery, Y5(i) indicates the discharge characteristics at the initial stage of the battery of the comparison example 5, and Y5(p) indicates the discharge characteristics after long-term storage of the battery of comparison example 5. Further, the 2> > a4o~

abscissa represents the discharge time (hour) and the ordinate represents the discharge voltage (V).
As is obvious from Fig. 9, the battery of embodiment 7 is excellent in its discharge characteristics at the initial stage and after long-term storage as compared with the battery of comparison example 5.
Further, 40 cells of the batteries of embodiment 7 and comparison example 5 were examined to check the fraction defective after manufacture. The number of defects was zero for the battery of embodiment 7, but it was five for the battery of comparison example 5. In other words, no defect was observed in the case of the battery of embodiment 7. This may be attributable to the fact that, in the battery of comparison example 5, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular compounds of formulas (XI) and (XII) were naturally polymerized to be formed into a thin film that is weak in mechanical strength, so that fine short-circuiting occurred easily.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of acrylic acid was examined. Fig. 10 shows the result. In Fig. 10, Ia, Ib and the rising rate are the same as in Fig. 3. As shown in Fig. 10, the rising rate of the internal impedance changes largely at a border point where the content of the acrylic acid is about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less. That is, when the content of acrylic acid was 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of internal impedance was restrained.
In embodiment 7 and the comparison example 5, when methacrylic acid was used in place of acrylic acid, the same result was obtained.
(Embodiment 8) This embodiment is different from embodiment 3 only in the following point. In the battery of this embodiment, the content of acrylic acid in the battery was 0.0180 wt%. The apparatus for setting the content as above and the manner of measuring the content of acrylic acid were the same as in embodiment 7.
(Comparison example 6) The battery of this comparison example is different from embodiment 8 only in the following point. In the battery of this comparison example, the content of acrylic acid in the battery was 0.1410 wt%.
(Test 6) Charge/discharge cycle tests were performed on the batteries of embodiment 8 and comparison example 6 in the same manner as in test 2 to examine the respective charge/discharge cycle characteristics at the initial stage and after long-term storage.
Fig. 11 shows the charge/discharge cycle characteristics at the initial stage and after long-term storage. In the figure, X8(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of embodiment 8, X8(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of embodiment 8, Y6(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of comparison example 6, and Y6(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of comparison example 6. The abscissa represents the number of charge/discharge cycles and the ordinate represents the battery capacity (mAh).
As is obvious from Fig. 11, the battery of embodiment 8 is excellent both in its charge/discharge cycle characteristics at the initial stage and its charge/discharge cycle characteristics after long-term storage, as compared with the battery of comparison example 6.
30 Cells of the batteries of embodiment 8 and comparison example 6 were examined to check the fraction defective after manufacture of the battery. The number of defects was zero for the battery of embodiment 8, but it was six for the battery of comparison example 6. In other words, no defect was observed in the case of the battery of embodiment 8. This may be attributable to the fact that, in the battery of comparison example 6, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular compounds of formulas (XI) and (XII) were naturally polymerized to be formed into a thin film that was weak in mechanical strength, so that fine short-circuiting occurred easily.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of acrylic acid was examined. Fig. 12 shows the result. In Fig. 12, Ia, Ib and the rising rate indicate the same as in Fig. 3. As shown in Fig. 12, the rising rate of the internal impedance changes largely at a border point where the content of acrylic acid is about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less.
That is, when the content of acrylic acid was 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of internal impedance was restrained.
In embodiment 8 and the comparison example 6, when methacrylic acid was used in place of acrylic acid, the same result was obtained.
(Embodiment 9) This embodiment relates to a film type primary battery which is an example of this invention. The fundamental structure of the battery is the same as that shown in Fig. 1.
The battery of this embodiment was made by the following processes (a) to (d).
(a) The cathode composite 2 was formed in the following manner. MnOz forming the positive active material was mixed with acetylene black forming the conductive material with a weight ratio of 85 to 15 under an atmosphere of dried inert gas (mixture A9). The mixture A9 was mixed with a xylene solution (2 wt% solution) of a copolymer of ethylene-propylene-1, 3-cyclohexadiene forming the binder with a weight ratio of 2.2 to 2 under an atmosphere of dried inert gas ( mixture B9 ) .

-. 21 18401 Weight parts of high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 4 to 6, were mixed with 1 weight part of LiC104 and 20 5 weight parts of propylene carbonate (mixture C9). The mixture B9 was mixed with the mixture C9 with a weight ratio of 20 to 3 under an atmosphere of dried inert gas (mixture D9). This mixture D9 was cast by means of screen coating onto the positive current collector plate 1 comprising stainless steel, 10 on the surface of which a conductive carbon film was formed, and was irradiated with an electron beam having an intensity of 8 Mrad, so as to be cured, after the xylene had been completely removed under the atmosphere of dried inert gas.
The film thickness of the cathode composite 2 formed on the positive current collector plate 1 was 60 um.
(b) The anode 4 was composed of lithium metal forming the negative active material, and formed by being press bonded to the negative current collector plate 5 comprising stainless steel.
(c) The electrolyte layer 3 was formed on the anode 4 in the following manner. 30 Weight parts of a high-molecular mixture, the same as that of process (a), were mixed with 6 weight parts of LiC104 and 64 weight parts of propylene carbonate (mixture E9). This mixture E9 was cast by means of screen coating on the anode 4, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The thickness of the electrolyte layer 3 formed on the anode 4 was 25 pm.

In processes (a) and (c), the high-molecular compounds of formulas (XI) and (XII) were prepared by an esterification reaction with polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst and an organic solvent, thereafter neutralization with NaOH, and then washing with a NaCl aqueous solution.
(d) A laminate of the electrolyte layer 3, the anode 4 and the negative current collector plate 5 prepared by process (c) and a laminate of the cathode composite 2 and the positive current collector plate 1 prepared by process (a) were brought into contact with each other at the cathode composite 2 and the electrolyte layer 3. Thereby, the battery shown in Fig. 1 was prepared.
In the battery of this embodiment, the respective contents of the alkali metal ion and the multivalent ion in the battery are shown in Table 2.
[Table 2]
Na+ K+ Ca2+ Fea+is+

0.005 wt% 0.002 wt% 0.001 wt% 0.001 wt%

Ni3+ C.O3+ Crs+

0.001 wt% 0.001 wt% 0.001 wt%

In order to set the contents as above, in this embodiment, when the high-molecular compounds of formulas (XI) and (XII) were prepared, neutralization with NaOH proceeded strictly, and washing was proceeded with as small a quantity as possible of NaCl aqueous solution and with a large quantity of distilled water.
The contents of each of the above ions were measured in the following manner. That is, the battery was subjected to a centrifugation process and extraction process at the same time as during the manufacture of the battery. Thereafter, each of the mixture D9 and the mixture E9 were measured quantitatively by means of an atomic absorption analysis method, ICP-AES
emission spectrochemical analysis method, etc. The measured values thus obtained were converted to that of the battery interior. The battery interior of this embodiment is composed of the cathode composite 2, the electrolyte layer 3, and the anode 4.
(Comparison example 7) The battery of this comparison example is different from that of embodiment 9 only in the following point. In the battery of this comparison example, the respective contents of the alkali metal ion and the multivalent ion in the battery are shown in Table 3.
[Table 3]
Na+ K+ Ca~+ Fe2+ia+

0.110 wt% 0.122 wt% 0.130 wt% 0.150 wt%

Ni3+ CO3+ ',r3+

0.120 wt% 0.110 wt% 0.115 wt%

(Test 7) Discharge tests were carried out on the batteries of embodiment 9 and comparison example 7, in the same manner as in test 1 to examine the respective discharge characteristics at the initial stage and after long-term storage.
Fig. 13 shows the discharge characteristics at the initial stage and after long-term storage. In the figure, X9(1) indicates the discharge characteristics at the initial stage of the battery of embodiment 9, X9(p) indicates the discharge characteristics after long-term storage of the battery of embodiment 9, Y7(i) indicates the discharge characteristics at the initial stage of the battery of comparison example 7, and Y7(p) indicates the discharge characteristics after long-term storage of the battery of comparison example 7. Further, the abscissa represents the discharge time (hour) and the ordinate represents a discharge voltage (V).
As is obvious from Fig. 13, the battery of embodiment 9 is excellent both in its discharge characteristics at the initial stage and the discharge characteristics after long-term storage, as compared with the battery of comparison example 7.
40 Cells of the batteries of embodiment 9 and comparison example 7 were examined to check the rate of occurrence of a short circuit or a fine short circuit after long-term storage.
The number of short circuit cells was zero for the battery of embodiment 9, but it was three for the battery of comparison example 7.
Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60 °C and the contents of Fez*~3;, Ni3+, Na' and K+ in the above respective ions were examined. Fig. 14 shows the result. In Fig. 14, Ia, Ib and the rising rate indicate the same as those of Fig. 3. As shown in Fig. 14, the rising rate of internal impedance of the battery changes largely at a border point where the contents of the above respective ions are about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less. That is, when the content of the above respective ions were 0.1 wt% or less, worsening of the battery efficiency caused by the rise of internal impedance of the battery was restrained.
(Embodiment 10) This embodiment relates to a film type secondary battery which is an example of this invention. The fundamental structure of the battery is the same as the battery shown in Fig. 1; however, 4 is an anode composite.
The battery of this embodiment was made by the following processes (a) to (d).
(a) The cathode composite 2 was formed in the following manner. LiCoOz forming the positive active material was mixed with acetylene black forming the conductive material under an atmosphere of dried inert gas with a weight ratio of 85 to 15 (mixture Alo). The mixture Alo was mixed with dimethylformamide solution (2 wt% solution) of polyacrylonitrile forming the binder with a weight ratio of 2.4 to 2 under an atmosphere of dried inert gas (mixture Blo).
10 Weight parts of high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.5 to 6.5, were mixed with 1 weight part of LiBF4, 10 weight parts of 1,2-dimethoxyethane and 10 weight parts of y-butyrolactone (mixture Cloy. The mixture Blo was mixed with the mixture Clo with a weight ratio of 17 to 3 under an atmosphere of dried inert gas (mixture Dlo). This mixture Dlo was cast by means of screen coating on the positive current collector plate 1 comprising aluminum, on the surface of which a conductive carbon film was formed, and irradiated with an electron beam having an intensity of 12 Mrad, so as to be cured, after the dimethylformamide was completely removed under the atmosphere of dried inert gas. The film thickness of the cathode composite 2 formed on the positive current collector plate 1 was 60 Nm.
(b) The anode composite 4 was formed in the following manner.
Carbon powder forming the negative active material was mixed with a xylene solution (2 wt% solution) of a copolymer of ethylene-propylene-cyclopentadiene forming the binder with a weight ratio of 2 to 5 under an atmosphere of dried inert gas (mixture Flo). 10 Weight parts of high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.2 to 6.8, were mixed with 1 weight part of LiBF4, 10 weight parts of 1,2-dimethoxyethane and 10 weight parts of ~-butyrolactone (mixture Glo). The mixture Flo was mixed with the mixture Glo with a weight ratio of 18 to 2 under an atmosphere of dried inert gas (mixture Hlo). This mixture Hlo was cast by means of screen coating onto the negative current collector plate 5 comprising copper, and irradiated with an electron beam having an intensity of 12 Mrad, so as to be cured, after the xylene was completely removed under the atmosphere of dried inert gas. The film thickness of the anode composite 4 formed on the negative current collector plate 5 was 30 Nm.
(c) The electrolyte layer 3 was formed on the cathode composite 2 in the following manner. 30 Weight parts of a high-molecular mixture, the same as that of process (a) were mixed with 6 weight parts of LiBFa, 32 weight parts of 1,2-dimethoxyethane and 32 weight parts of y-butyrolactone (mixture Ela). This mixture Elo was cast by means of screen coating on the cathode composite 2, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the electrolyte layer 3 formed on the cathode composite 2 was 45 Nm.
In processes (a) to (c), the manufacturing method for the high-molecular compounds of formulas (XI) and (XII) and the apparatus for the manufacture were the same as in embodiment 9. That is, the high-molecular compounds of formulas (XI) and (XII) were prepared by an esterification reaction with polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst and organic solvent, thereafter neutralization with NaOH and then washing with NaCl aqueous solution. And, in this embodiment, when the high-molecular compounds of formulas (XI) and (XII) were prepared, neutralization with NaOH proceeded strictly, and washing was proceeded with as small a quantity as possible of a NaCl aqueous solution and with a large quantity of distilled water.
(dj A laminate of the anode composite 4 and the negative current collector plate 5 prepared by process (bj and a laminate of the electrolyte layer 3, the cathode composite 2 and the positive current collector plate 1 prepared by process (c) were brought into contact with each other at the anode composite 4 and the electrolyte layer 3.
In the battery of this embodiment, the respective contents of the alkaline metal ion and the multivalent ion in the battery are shown in Table 4.
[Table 4]
Na+ K+ Caz+ Fez+i3+

0.005 wt% 0.002 wt% 0.001 wt% 0.001 wt%

Ni3+ Co3+ Cr3+

O.OO1 Wt$ O.OO1 Wt% O.OO1 Wt$

The contents of the above respective ions were measured in the same manner as in embodiment 9. That is, the battery was subjected to a centrifugation process and an extraction process during manufacture of the battery. Thereafter, each of the mixture Dlo, the mixture Elo and the mixture Hlo were measured quantitatively by means of an atomic absorption analysis method, an ICP-AES emission spectrochemical analysis method, etc. The measured values thus obtained were converted to that of the battery interior. The battery interior of this w 2118401 embodiment is composed of the cathode composite 2, the electrolyte layer 3, and the anode composite 4.
(Comparison example 8) The battery of this comparison example is different from that of embodiment 10 only in the following point. In the battery of this comparison example, the respective contents of the alkali metal ion and the multivalent ion in the battery are shown in Table 5.
[Table 5]
._- -~-Na+ K+ Ca2+ Fe2+/3a 0.110 wt% 0.122 wt% 0.130 wt% 0.150 wt%

Ni3+ Co3+ Crs+

0.120 wt% 0.110 wt% 0.115 wt%

(Test 8) Charge/discharge cycle tests were carried out on the batteries of embodiment 10 and comparison example 8 to examine the respective charge/discharge cycle characteristics at the initial stage and after long-term storage. The electrode surface area could be changed variously depending on the manufacturing process; however, it was set at 100 cmz in these tests.
Conditions of the charge/discharge cycle test were a temperature of 25°C, a constant-current constant-voltage charge at 100 NA/cmZ, constant-current discharge at 100 pA/cm2, a charge end voltage of 4.2 V and discharge end voltage of 2.7 V.
The period of long-term storage was 100 days at 60°C.

Fig. 15 shows the charge/discharge cycle characteristics at the initial stage and after long-term storage. In the figure, X10(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of embodiment 10, X10(p) indicates the charge/discharge cycle characteristics after storage of the battery of embodiment 10, Y8(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of comparison example 8, and Y8(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of comparison example 8. Further, the abscissa represents the charge/discharge cycle number (time) and the ordinate represents the battery capacity (mAh).
As is obvious from Fig. 15, the battery of embodiment 10 is excellent both in the charge/discharge cycle character-istics at the initial stage and after long-term storage as compared with the battery of comparison example 8.
15 Cells of the batteries of embodiment 10 and the com-parison example 8 were examined to check the rate of occurrence of a short circuit or a fine short circuit during the charge/discharge cycle. The number of short circuit cells was zero for the battery of embodiment 10, but it was two for the battery of comparison example 8.
Further, the relation between the rising rate of internal impedance of the battery after storage for 100 days at 60°C
and the contents of Fe~'~3+, Ni'~, Na+ and K+ in the above respective ions were examined. Fig. 16 shows the result. In Fig. 16, Ia, Ib and the rising rate indicate the same as in Fig. 3. As shown in Fig. 16, the rising rate of the internal impedance of the battery changes largely at a border point where the contents of the above respective ions are about 0.1 wt%. The rising rate was extremely small at 0.1 wt% or less. That is, when the contents of the above respective ions were 0.1 wt% or less, the worsening of the battery efficiency caused by the rise of internal impedance of the battery was restrained.
(Embodiment 11) This embodiment relates to a film type primary battery which is an example of this invention. The fundamental structure of the battery is the same as that of the battery shown in Fig. 1.
The battery of this embodiment was made by the following processes (a) to (d).
(a) The cathode composite 2 was formed in the following manner. MnOZ forming the positive active material was mixed with acetylene black forming the conductive material with a weight ratio of 85 to 15 (mixture All). The mixture All was mixed with a xylene solution (2 wt% solution) of a copolymer of ethylene-propylene-1, 3-cyclohexadiene forming the binder with a weight ratio of 2.2 to 2 under an atmosphere of dried inert gas ( mixture B11 ) .
10 Weight parts of a high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 4 to 6, were mixed with 1 weight part of LiC104 and 20 weight parts of propylene carbonate (mixture C11). The mixture H11 was mixed with the mixture C11 with a weight ratio of 10 to 3 under an atmosphere of dried inert gas (mixture Dli). This mixture D11 was cast by means of screen coating onto the positive current collector plate 1 comprising stainless steel, on the surface of which a conductive carbon film was formed, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the cathode composite 2 formed on the positive current collector plate 1 was 60 Nm.
(b) The electrolyte layer 3 was formed on the cathode composite 2 in the following manner. 30 Weight parts of high-molecular mixture, the same as that of process (a) were mixed with 6 weight parts of LiC104 and 64 weight parts of propylene carbonate (mixture E11). This mixture E~1 was cast by means of screen coating onto the cathode composite 2, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The thickness of the electrolyte layer 3 formed on the cathode composite 2 was 25 Nm.
In processes (a) and (b), the high-molecular compounds of formulas (XI) and (XII) were prepared in such a way that an esterification reaction was carried out by using polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst, the compounds of formulas (XIII) and (XIV) forming the radical scavenger and organic solvent; and the prepared material was neutralized by using alkali metal hydroxide and then washed by using NaCl aqueous solution.

OH--(O OCH~
...(xIII) CH CH
OH I
H C-C C-C H

C H3 O C H3 ...(xIV) (c) The anode 4 was composed of lithium metal forming the negative active material, and formed by being press bonded to the negative current collector plate 5 comprising stainless steel.
(d) A laminate of the electrolyte layer 3, the cathode composite 2 and the positive current collector plate 1 prepared by the process (b) and a laminate of the anode 4 and the negative current collector plate 5 prepared by the process (c) were brought into contact with each other at the electrolyte layer 3 and the anode 4. Thereby, a battery that had the same structure as that of the battery shown in Fig. 1 was prepared.
In the battery of this embodiment, the contents of the compounds of formulas (XIII) and (XIV) in the battery were both 0.010 wt%. In order to set the contents as above, in this embodiment, the quantity of the high-molecular compounds --~ 21 18401 of formulas (XIII) and (XIV) to be added were fixed in advance.
The contents of the compounds of formulas (XIII) and (XIV), that is the radical scavenger, were measured in the following manner. The battery was subjected to a centrifugation process and extraction process at the same time as manufacture of the battery. Thereafter, each of the mixture D11 and the mixture E11 Were measured quantitatively by means of a colorimetric determination method, redox titration method, etc. In the colorimetric determination method, for example, a nitroso compound was measured quantitatively by adding sodium sulphite. The measured values thus obtained were converted to that of the battery interior. The battery interior of this embodiment is composed of the cathode composite 2, the electrolyte layer 3, and the anode 4.
(Comparison example 9) The battery of this comparison example is different from that of the embodiment 11 only in the following point. In the battery of this comparison example, the radical scavenger was not used at the time of manufacture of the battery.
Therefore, the battery of this comparison example contains no radical scavenger.
(Test 9) Discharge tests were done on the battery of embodiment 11 and comparison example 9 in the same manner as test 1 to examine the respective discharge characteristics at the initial stage and after long-term storage.

--~ 21 18401 Fig. 17 shows the discharge characteristics at the initial stage and after long-term storage. In the figure, X11(i) indicates the discharge characteristics at the initial stage of the battery of embodiment 11, X11(p) indicates the discharge characteristics after long-term storage of the battery of embodiment 11, Y9(i) indicates the discharge characteristics at the initial stage of the battery of comparison example 9, and Y9(p) indicates the discharge characteristics after long-term storage of the battery of comparison example 9. Further, the abscissa represents the discharge time (hour) and the ordinate represents the discharge voltage (V).
As is obvious from Fig. 17, the battery of embodiment 11 is excellent both in its discharge characteristics at the initial stage and after long-term storage as compared with the battery of comparison example 9.
40 Cells of the batteries of embodiment 11 and comparison example 9 were examined to check the fraction of defects at the time of manufacture of the battery. The number of defects was zero for the battery of embodiment 11, but it was eight for the battery of comparison example 9. This may be attributable to the fact that, in the battery of comparison example 9, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular compounds of formulas (XI) and (XII) were naturally polymerized to form a thin film that is weak in mechanical strength, so that a fine short-circuit could occur easily.

Further, the relation between the rising rate of the internal impedance of the battery after storage for 100 days at 60°C and the content of the radical scavenger were examined. When the content of the radical scavenger was 0.1 wt% or less, the rising rate was extremely small.
(Embodiment 12) This embodiment relates to a film type secondary battery which is an example of this invention. The fundamental structure of the battery is the same as that of the battery shown in Fig. 1; however, 4 is an anode composite.
The battery of this embodiment was made by the following processes (a) to (e).
(a) The cathode composite 2 was formed in the following manner. LiCoOz forming the positive active material was mixed with acetylene black forming the conductive material with a weight ratio of 85 to 15 (mixture Alz). The mixture Alz was mixed with dimethylformamide solution (2 wt% solution) of a polyacrylonitrile forming the binder with a weight ratio of 2.4 to 2 under an atmosphere of dried inert gas (mixture Blz).
10 Weight parts of high-molecular mixture prepared by mixing the high-molecular compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.5 to 6.5, were mixed with 0.02 weight part of a principal-chain straight-chain polyethylene oxide, 1 weight part of LiBF4, 10 weight parts of 1,2-dimethoxyethane and 10 weight parts of ~-butyrolactone (mixture Clz). The mixture Blz was mixed with the mixture Clz with a weight ratio of 10 to 3 under an atmosphere of dried inert gas (mixture Dlz). This mixture D1z was cast by means of screen coating onto the positive current collector plate 1 comprising aluminum, on the surface of which a conductive carbon film was formed, and irradiated with an electron beam having an intensity of 12 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the cathode composite 2 formed on the positive current collector plate l was 60 um.
(b) The electrolyte layer 3 was formed on the cathode composite 2 in the following manner. 30 Weight parts of high-molecular mixture, the same as that of process (a) were mixed with 0.06 weight part of a principal-chain straight-chain polyethylene oxide, 6 weight parts of LiBF4, 32 weight parts of 1,2-dimethoxyethane and 32 weight parts of y-butyrolactone (mixture E12). This mixture E12 was cast by means of screen coating on the cathode composite 2 under an atmosphere of dried inert gas, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the electrolyte layer 3 formed on the cathode composite 2 was 25 Nm.
(c) The anode composite 4 was formed in the following manner.
Carbon powder forming the negative active material was mixed with a toluene solution (2 wt% solution) of a copolymer of ethylene-propylene-cyclopentadiene forming the binder with a weight ratio of 2 to 5 under an atmosphere of dried inert gas (mixture F12). 10 Weight parts of a high-molecular mixture prepared by mixing the high-molecular-compound of formula (XI) with the high-molecular compound of formula (XII) with a weight ratio of 3.2 to 6.8, were mixed with 1 weight part of LiBF4, 10 weight parts of 1,2-dimethoxyethane and 10 weight parts of ~-butyrolactone (mixture G1z). The mixture F1z was mixed with the mixture G1z with a weight ratio of 8 to 2 under an atmosphere of dried inert gas (mixture H1z). This mixture Hlz was cast by means of screen coating onto the negative current collector plate 5 comprising stainless steel, and irradiated with an electron beam having an intensity of 12 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the anode composite 4 formed on the negative current collector plate 5 was 30 pm.
(d) The electrolyte layer 3 was formed on the anode composite 4 in the following manner. 30 Weight parts of the same high-molecular mixture as in process (a) were mixed with 6 weight parts of LiBF4, 32 weight parts of 1,2-dimethoxyethane and 32 weight parts of y-butyrolactone (mixture I12). This mixture Ila was cast by means of screen coating on the anode composite 4 under an atmosphere of dried inert gas, and irradiated with an electron beam having an intensity of 8 Mrad under an atmosphere of dried inert gas, so as to be cured. The film thickness of the electrolyte layer 3 formed on the anode composite 4 was 25 Nm.
In processes (a) to (d), the manufacturing method for the high-molecular compounds of formulas (XI) and (XII) and the apparatus for the manufacture were the same as were used for embodiment 11. The high-molecular compounds of formulas (XI) and (XII) were prepared in such a way that an esterification reaction was carried out by using polyethylene glycol, acrylic acid, sulphuric acid forming an acid catalyst, the compounds of formulas (XIII) and (XIV) forming the radical scavenger, and an organic solvent; and the prepared material was neutralized by using alkali metal hydroxide and then washed by using an NaCl aqueous solution. And, in this embodiment, the quantity of the high-molecular compound of formulas (XIII) and (XIV) to be added were fixed in advance.
(e) A laminate of the electrolyte layer 3, the cathode composite 2 and the positive current collector plate 1 prepared by process (b) and a laminate of the electrolyte layer 3, the anode composite 4 and the negative current collector plate 5 prepared by process (d) were brought into contact with each other at the respective electrolyte layers 3.
In the battery of this embodiment, the contents of the compounds of formulas (XIII) and (XIV) in the battery were both 0.010 wt%. In order to set these contents, the quantity of high-molecular compounds of formulas (XIII) and (XIV) to be added was fixed in advance.
The contents of the compounds of formulas (XIII) and (XIV), that is the radical scavenger, were measured in the same manner as in embodiment 11. The battery was subjected to a centrifugation process and an extraction process during manufacture of the battery. Thereafter, each of the mixture Dlz, the mixture EIZ, the mixture H12 and the mixture IlZ were measured quantitatively by means of a colorimetric determination method, redox titration method, etc. The measured values thus obtained were converted to that of the battery interior. The battery interior of this embodiment is composed of the cathode composite 2, the electrolyte layer 3, and the anode composite 4.
(Comparison example 10) The battery of this comparison example is different from that of embodiment 12 only in the following point. In the battery of this comparison example, the radical scavenger was not used at the time of manufacture of the battery.
Therefore, the battery of this comparison example contains no radical scavenger.
(Test 10) Charge/discharge cycle tests were performed on the batteries of embodiment 12 and comparison example 10 in the same manner as test 2 to examine respective charge/discharge cycle characteristics at the initial stage and after long-term storage.
Fig. 18 shows the charge/discharge cycle characteristics at the initial stage and after long-term storage. In the figure, X12(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of embodiment 12, X12(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of embodiment 12, Y10(i) indicates the charge/discharge cycle characteristics at the initial stage of the battery of comparison example 10, and Y10(p) indicates the charge/discharge cycle characteristics after long-term storage of the battery of comparison example 10. Further, the abscissa represents the charge/discharge cycle number (time) and the ordinate represents the battery capacity (mAh).

.-- 21 18401 As is obvious from Fig. 18, the battery of embodiment 12 is excellent both in its charge/discharge cycle characteristics at the initial stage and after long-term storage as compared with the battery of comparison example 10.
40'Cells of the batteries of embodiment 12 and comparison example 10 were examined to check the fraction of defects after manufacture of the battery. The number of defects was zero for the battery of embodiment 12, but it was eight for the battery of comparison example 10. In other words, no defect was observed in the case of the battery of embodiment 12. This may be attributable to the fact that, in the battery of comparison example 10, before the thin film comprising the ion-conductive high-molecular compound was formed, the high-molecular.compounds of formulas (XI) and (XII) were naturally polymerized to form a thin film that is weak in mechanical strength, so that a fine short-circuit could occur easily.
Further, the relation between the rising rate of internal impedance of the battery after storage for 100 days at 60°C
and the content of the radical scavenger was examined. When the content of the radical scavenger was about 0.1 wt% or less, the rising rate was extremely small.

Claims

Claims:

1. A battery containing:
(A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material;
(B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode comprising a composite having an ion-conductive high-molecular compound and a negative active material;
characterized in that the concentration, contained in the battery, of sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid is limited to 0.1 wt% or less.

2. A battery containing:
(A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material;
(B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode composed of a negative active material;
characterized in that the concentration, contained in the battery, of sulphate ion, para-toluenesulfonate ion, chlorine ion, polyethylene glycol, acrylic acid and methacrylic acid is limited to 0.1 wt% or less.

3. A battery containing:
(A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material;
(B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode comprising a composite having an ion-conductive high-molecular compound and a negative active material;
characterized in that the concentration, contained in the battery, of a multivalent ion and an alkali metal ion, other than lithium ion, is limited to 0.1 wt% or less.

4. A battery containing:
(A) a cathode composite comprising an ion-conductive high-molecular compound and a positive active material;
(B) an electrolyte being composed of the in-conductive high-molecular compound; and (C) an anode composed of a negative active material and allowing ionic conduction performed by lithium ion;
characterized in that the concentration, contained in the battery, of a multivalent ion and an alkali metal ion, other than lithium ion, is limited to 0.1 wt% or less.

5. A battery having in its interior a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material;
characterized in that a radical scavenger is included in the battery and its content is controlled to 0.1 wt% or smaller.

6. A battery having in its interior a cathode composite having an ion-conductive high-molecular compound as its composition material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode comprising an electrode active material;
characterized in that a radical scavenger is included in the battery and its content is controlled to 0.1 wt% or smaller.

7. A battery as set forth in any one of claims 1 through 6, in which the ion-conductive high-molecular compound is one prepared by polymerizing at least one kind of high-molecular compounds shown in formula (I) and formula (II) while including at least one kind of ionic compound, and said high-molecular compound is one that is prepared in such a way that an esterification reaction is carried out by using polyethylene glycol, acrylic acid or methacrylic acid, sulphuric acid or para-toluenesulfonic acid, and an organic solvent; and the thus prepared high-molecular compound is neutralized by using alkali metal hydroxide and then washed by using an alkali metal chloride aqueous solution, (R1, R2 and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m >= 1, n >= 0 and n/m = 0 to 5.) (R4, R5 and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s >= 3, t >= 0 and t/s = 0 to 5).

8. A battery as set forth in any one of claims 1 through 6, in which at least the cathode composite or anode composite includes a binder.

9. A battery as set forth in any one of claims 3 and 4, in which the alkali metal ion is Na+ or K+, and the multivalent ion is Ca2+, Fe2+, Cu2+, Ni3+, Fe3+, Co3+ or Cr3+.

10. A battery as set forth in any one of claims 5 and 6, in which the radical scavenger is at least one kind of compound shown by formula (III), formula (IV), formula (V) and formula (VI) (R11 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R12 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R13 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R14, R15, R16 represent a lower alkyl group or a lower alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group).

11. A manufacturing method for a battery containing a cathode composite comprising an ion-conductive high-molecular compound and a positive active material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode composite having the ion-conductive high-molecular compound as its composition material;
characterized in that at least one kind of high-molecular compound shown by formula (I) and formula (II) is used, the high-molecular compound is polymerized to manufacture an ion-conductive high-molecular compound while including at least one kind of ionic compounds, and a radical scavenger is included in said high-molecular compound, (R1, R2 and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m >= 1, n >= 0 and n/m = 0 to 5.) (R9, R5 and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s >= 3, t >= 0 and t/s = 0 to 5).

12. A manufacturing method for a battery containing a cathode composite having an ion-conductive high-molecular compound and a positive active material, an electrolyte comprising the ion-conductive high-molecular compound, and an anode comprising an electrode active material;
characterized in that at least one kind of high-molecular compound shown by formula (I) and formula (II) is used, the high-molecular compound is polymerized to manufacture an ion-conductive high-molecular compound while including at least one kind of ionic compounds, and a radical scavenger is included in said high-molecular compound, (R1, R2 and R3 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and m and n represent an integer in the range of m >= 1, n >= 0 and n/m = 0 to 5.) (R4, R5 and R6 represent a hydrogen group or a lower alkyl group having a carbon number of 1 or larger, and s and t represent an integer in the range of s >= 3, t >= 0 and t/s = 0 to 5).

13. A manufacturing method for a battery as set forth in any one of claims 11 and 12, in which the content of the radical scavenger is controlled to 0.1 wt% or smaller.

14. A manufacturing method for a battery as set forth in any one of claims 11 and 12, in which the radical scavenger is at least one kind of compound shown by formula (III), formula (IV), formula (V) and formula (VI) (R11 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R12 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R13 represents an alkyl group or an alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group.) (R14, R15, R16 represent a lower alkyl group or a lower alkoxyl group, which has a carbon number of 1 or larger, or a hydroxyl group).