JP3692656B2 - Non-aqueous secondary battery - Google Patents

Description

【００６３】
【発明の効果】
表１の結果からあきらかな様に、正極に活物質非含有層を設けた本発明の電池は、巻回時の正極割れが改良され放電電流依存性も最上層に活物質非含有層を設けた場合より優れている。
【図面の簡単な説明】
【図１】一般的な円筒型電池の縦断面図である。
【符号の説明】
１．正極シート
２．負極シート
３．セパレータ
４．電池缶
５．電池蓋
６．ガスケット
７．安全弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-aqueous secondary battery in which the flexibility of a positive electrode sheet is improved to prevent the mixture from falling off during winding.
[0002]
[Prior art]
In recent years, the demand for high-capacity secondary batteries as power sources for electronic devices such as mobile phones, video cameras and laptop computers, especially non-aqueous secondary batteries using lithium ion insertion / release reaction, has increased. It is desired to increase the capacity of the secondary battery along with the improvement of the function of the electronic device. Therefore, the present inventors have achieved a high capacity by using a specific metal oxide having a high lithium ion storage capacity as the negative electrode active material. However, since the capacity of the positive electrode active material remains the same as before, the proportion of the positive electrode active material must be increased as compared with the conventional amount as the amount to be filled in the battery, and for this purpose, the mixture layer thickness of the positive electrode sheet must be increased. become.
As a form of the non-aqueous secondary battery, it is common to place a winding group in which a stack of sheet-like positive electrode, negative electrode and separator is wound in a spiral shape into a cylindrical battery. The positive and negative electrode sheets must be flexible so that the sheet can be wound in a correct circular shape without cracking, but in order to obtain a high capacity, it is necessary to increase the active material content in the mixture as much as possible. As a result, the flexibility becomes insufficient. If the flexibility is insufficient, the thicker the mixture layer, the easier the sheet breaks, and the active material tends to fall off. Therefore, in the system using the metal oxide negative electrode active material of the present invention, it is necessary to improve the flexibility of the positive electrode sheet.
In order to prevent the active material from falling off the sheet, Japanese Patent Laid-Open No. 63-121265 discloses that a metal current collector is coated with a conductive coating film. In this patent, the conductive coating film is composed of a conductive filler such as carbon black or metal powder and a binder, but such a configuration is insufficient to satisfy the above flexibility.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a non-aqueous secondary battery that improves the flexibility of the positive electrode sheet , prevents the mixture from falling off during winding, and has high discharge current dependency .
[0004]
[Means for Solving the Problems]
The subject of the present invention is
A positive electrode sheet formed by applying a mixture containing a positive electrode active material which is a lithium-containing transition metal oxide; a negative electrode sheet formed by applying a mixture containing a negative electrode material capable of occluding and releasing lithium; and lithium metal In an electrolyte comprising a non-aqueous electrolyte containing a salt, the positive electrode sheet comprises an electron conductive particle, a non-electron conductive particle, and a positive electrode active material-free layer containing a binder as a lithium-containing transition metal oxide. Between the electron-containing particles and the non-electron-conductive particles contained in the mixture containing a certain positive electrode active material or in the lowermost layer of the mixture, and contained in the positive electrode active material non-containing layer This was achieved by a non-aqueous secondary battery characterized in that a ratio of 1:99 to 50: 50% by weight was used.
[0005]
Although the preferable aspect of this invention is as follows, these are examples and it is not necessary to limit to these.
(1) A positive electrode sheet formed by applying a mixture containing a positive electrode active material that is a lithium-containing transition metal oxide; and a negative electrode sheet formed by applying a mixture containing a negative electrode material capable of occluding and releasing lithium. In the electrolyte comprising a non-aqueous electrolyte containing a lithium metal salt, the positive electrode sheet comprises the positive electrode active material-free layer containing electron conductive particles, non-electron conductive particles, and a binder. Electron conductive particles and non-electron conduction which are present in the mixture containing the positive electrode active material which is an oxide or in the lowermost layer of the mixture and contained in the positive electrode active material non-containing layer What is used is a non-aqueous secondary battery in which the ratio of the conductive particles is 1:99 to 50: 50% by weight .
(2) The ratio of the coating amount of the mixture layer above the positive electrode active material non-containing layer and the mixture layer below is 10: 0 to 1: 9, Non-aqueous secondary battery.
(3) The nonaqueous secondary battery according to item 1, wherein the electron conductive particles are at least one compound selected from carbon blacks, graphites and metal powders.
(4) Item 1 wherein the non-conductive particles are at least one compound selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, silicon dioxide, zirconium silicate, mica, kaolinite, smectite, and pyrophyllite. Non-aqueous secondary battery.
(5) The nonaqueous secondary battery according to item 1 , wherein the binder is at least one polymer selected from the group consisting of a polysaccharide having a decomposition temperature of 300 ° C. or higher, a thermoplastic resin, and a polymer having rubber elasticity .
(6) The nonaqueous secondary battery according to any one of items 1 to 5, wherein the positive electrode active material contains at least one lithium-containing transition metal composite oxide .
(7) In any one of Items 1 to 6, wherein the electrolytic solution constituting the electrolyte comprising the non-aqueous electrolyte containing the lithium metal salt is a solvent containing a cyclic carbonate and / or a non-cyclic carbonate. The non-aqueous secondary battery as described.
(8) The nonaqueous secondary battery according to any one of items 1 to 7, wherein the lithium metal salt constituting the electrolyte comprising the nonaqueous electrolyte containing the lithium metal salt includes LiPF ₆ .
(9) The nonaqueous secondary battery according to any one of items 1 to 8, wherein the negative electrode material is a metal or a metalloid oxide .
(10) to claim the layer mainly composed of a metal or metalloid oxide of the negative electrode material, a metal from the Periodic Table 13 Group 15, characterized in that the oxide of the metalloid elements is at least one comprising a layer 9. The nonaqueous secondary battery according to 9 .
(11) A nonaqueous secondary battery, wherein the negative electrode material according to item 10 is a composite oxide of the following general formula (1).
SnM ¹ aOt general formula (1)
In the formula, M ¹ represents two or more elements selected from Al, B, P, Si, Ge, Group 1 element, Group 2 element, Group 3 element, and halogen element in the periodic table, and a is 0 .2 represents a number of 2 or less, and t represents a number of 1 or more and 6 or less.
(12) The non-aqueous secondary battery according to item 11, wherein the composite oxide containing tin is a composite oxide of the following general formula (4).
SnM ³ cM ⁴ dOt general formula (4)
In the formula, M ³ represents at least one of Al, B, P, and Ge, M ⁴ represents at least one of Group 1 element, Group 2 element, Group 3 element, and halogen element in the periodic table, c Is a number of 0.2 or more and 2 or less, d is a number of 0.01 or more and 1 or less, 0.2 <c + d <2, and t is a number of 1 or more and 6 or less.
[0006]
In the present invention, the positive electrode sheet includes a positive electrode active material-free layer containing electron conductive particles, non-electron conductive particles, and a binder, and a mixture containing a positive electrode active material that is a lithium-containing transition metal oxide. Or it exists in the lowest layer of this mixture.
The ratio of the coating amount of the mixture layer in the upper layer and the mixture layer in the lower layer is preferably 10: 0 to 1: 9, and more preferably 10: 0 to 2: 8. The thickness of the active material non-containing layer is preferably 0.8% to 50%, more preferably 1.5% to 40% of the mixture layer. The material constituting the active material non-containing layer contains electron conductive particles, non-electron conductive particles, and a binder. The electron conductive particles are preferably carbon blacks such as acetylene black, ketjen black and furnace black, graphites such as natural graphite and artificial graphite, or metal powder. As the non-electron conductive particles, aluminum oxide, titanium oxide, zirconium oxide, silicon dioxide, zirconium silicate, mica, kaolinite, smectite, pyrophyllite and the like are preferable. The binder may be anything as long as it can be used in the mixture layer, and may be the same as or different from the binder contained in the mixture layer. Specific binder will be described later. The use ratio of the electron conductive particles and the non-electron conductive particles constituting the active material-free layer is preferably 1:99 to 50:50 wt%, and more preferably 5:95 to 50:50 wt%.
[0007]
The positive and negative electrodes used in the non-aqueous secondary battery of the present invention can be prepared by coating a positive electrode mixture or a negative electrode mixture on a current collector. The positive and negative electrodes may have a protective layer or the like introduced for the purpose of mechanical protection or chemical protection of the mixture layer in addition to the mixture layer containing the positive electrode active material or the negative electrode material.
In addition to the positive electrode active material or the negative electrode material, the positive electrode or the negative electrode mixture can contain a conductive agent, a binder, a dispersant, a filler, an ionic conductive agent, a pressure enhancer, and various additives, respectively.
[0008]
The positive electrode active material used in the present invention may be any compound that can occlude / release light metal ions, and is particularly selected from transition metal oxides and transition metal chalcogenides. A transition metal oxide is particularly preferable, and a transition metal oxide containing lithium is particularly preferable.
[0009]
Preferred transition metals used in the present invention include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, and W. Among these transition metal compounds, manganese dioxide, five Vanadium oxide, iron oxide, molybdenum oxide, molybdenum sulfide, cobalt oxide, iron sulfide, titanium sulfide, and the like are preferable. These compounds can be used alone or in combination of two or more. Moreover, it can also be used as a transition metal oxide containing lithium.
[0010]
In addition to lithium compounds and transition metal compounds, generally, compounds that increase ionic conductivity, such as Ca ²⁺ , or amorphous network formers such as P, B, and Si (for example, P ₂ O ₅ , Li ₃ PO ₄ , H ₃ BO ₃ , B ₂ O ₃ , SiO _2, etc.) may be mixed and fired. Alternatively, alkali metal ions such as Na, K, and Mg and / or a compound containing Si, Sn, Al, Ga, Ge, Ce, In, Bi, or the like may be mixed and fired. The transition metal oxide containing lithium can be synthesized, for example, by firing a mixture of a lithium compound and a transition metal compound.
[0011]
Specific examples of preferable positive electrode active materials used in the present invention include JP-A No. 61-5262, US Pat. No. 4,302,518, JP-A No. 63-299056, JP-A No. 1-294364, JP-B-4-30146, US Pat. Nos. 5,240,794, 5,153,081, JP-A-4-328,258, JP-A-5-54,889 and the like. Representative compounds are shown below, but the present invention is not limited thereto.
[0012]
_{Li x CoO 2, Li x NiO} 2, Li x Co a Ni 1-a O 2, Li x Co b V 1-b O z, Li x Co b Fe 1-b O z, Li x Mn 2 O 4, _{Li x MnO 2, Li x Mn} 2 O 3, Li x Mn b Co 2-b O z, Li x Mn b Ni 2-b O z, Li x Mn b V 2-b O z, Li x Mn b Fe _1-b O _z , Li _x Co _c B _1-c O ₂ (where x = 0.05 to 1.2, a = 0.1 to 0.9, b = 0.8 to 0.98, c = 0.85-0.99, z = 1.5-5).
[0013]
The positive electrode active material used in the present invention can be synthesized by a method in which a lithium compound and a transition metal compound are mixed and fired, or by a solution reaction, and the firing method is particularly preferable.
Details for firing are described in paragraphs [0035] of JP-A-6-60,867, JP-A-7-14,579, and the like, and these methods can be used. The positive electrode active material obtained by firing may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.
Furthermore, as a method of chemically inserting lithium ions into the transition metal oxide, a method of synthesis by reacting lithium metal, a lithium alloy or butyl lithium with a transition metal oxide may be used.
[0014]
The average particle size of the positive electrode active material used in the present invention is not particularly limited, but is preferably 0.1 to 50 μm. The volume of particles of 0.5 to 30 μm is preferably 95% or more. More preferably, the volume occupied by a particle group having a particle size of 3 μm or less is 18% or less of the total volume, and the volume occupied by a particle group of 15 μm or more and 25 μm or less is 18% or less of the total volume. No particular limitation is imposed on the specific surface area is preferably 0.01 to 50 m ² / g by the BET method, particularly preferably 0.2m ² / g~1m ² / g. The pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.
[0015]
When the positive electrode active material of the present invention is obtained by firing, the firing temperature is preferably 500 to 1500 ° C, more preferably 700 to 1200 ° C, and particularly preferably 750 to 1000 ° C. The firing time is preferably 4 to 30 hours, more preferably 6 to 20 hours, and particularly preferably 6 to 15 hours.
[0016]
The negative electrode material used in the present invention may be any compound that can occlude / release light metal ions. In particular, light metals, light metal alloys, carbonaceous compounds, inorganic oxides, inorganic chalcogenides, metal complexes, and organic polymer compounds are preferable. These may be used alone or in combination. Examples include light metals and carbonaceous compounds, light metals and inorganic oxides, and combinations of light metals, carbonaceous compounds, and inorganic oxides. These negative electrode materials are preferable because they provide high capacity, high discharge potential, high safety, and high cycle effect.
[0017]
Lithium is preferred as the light metal. Examples of the light metal alloy include a metal that forms an alloy with lithium or an alloy containing lithium. Al, Al—Mn, Al—Mg, Al—Sn, Al—In, and Al—Cd are particularly preferable.
The carbonaceous compound is preferably selected from natural graphite, artificial graphite, vapor-grown carbon, baked carbon of an organic substance, and the like, and includes a graphite structure. In addition to carbon, the carbonaceous compound may contain 0 to 10% by weight of a heterogeneous compound, for example, B, P, N, S, SiC, B ₄ C.
[0018]
As an element forming oxide or chalcogenide, a transition metal, a metal of group 13 to 15 of the periodic table, or a metalloid element is preferable.
[0019]
As the transition metal compound, V, Ti, Fe, Mn, Co, Ni, Zn, W, Mo alone or a composite oxide or chalcogenide is particularly preferable. More preferred compounds, Li _p of JP-A 6-44,972 No. claimed _{Co q V 1-q O r} ( wherein p = 0.1~2.5, q = 0~1, z = 1.3~ 4.5).
[0020]
As a compound of a metal other than a transition metal or a semimetal, a group 13-15 element of the periodic table, Al, Ga, Si, Sn, Ge, Pb, Sb, Bi alone or a combination of two or more thereof An oxide consisting of chalcogenide is selected.
For example, Al ₂ O ₃ , Ga ₂ O ₃ , SiO, SiO ₂ , GeO, GeO ₂ , SnO, SnO ₂ , SnSiO ₃ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , Bi ₂ O ₅ , SnSiO ₃ , GeS, GeS ₂ , SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , SnSiS _{3 and the} like are preferable. These may be composite oxides with lithium oxide, such as Li ₂ GeO ₃ and Li ₂ SnO ₂ .
[0021]
The complex chalcogen compound and complex oxide are preferably mainly amorphous when assembled into a battery. The term “amorphous” as used herein refers to an X-ray diffraction method using CuKα rays, which has a broad scattering band having a peak at 20 ° to 40 ° with a 2θ value, and has a crystalline diffraction line. Also good. Preferably, the strongest intensity of the crystalline diffraction lines seen at 2θ values of 40 ° or more and 70 ° or less is 500 of diffraction line intensities at the apexes of broad scattering bands seen at 2θ values of 20 ° or more and 40 ° or less. It is preferably not more than twice, more preferably not more than 100 times, particularly preferably not more than 5 times, and most preferably not having a crystalline diffraction line.
[0022]
The above-mentioned composite chalcogen compound and composite oxide are composite compounds composed of transition metals and Group 15 elements from Periodic Table 13, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, P, As. , Sb, Bi are more preferably a complex chalcogen compound or complex oxide mainly composed of two or more elements. More preferred are complex oxides.
Particularly preferred are composite oxides mainly composed of two or more elements of B, Al, Si, Ge, Sn, and P.
These composite chalcogen compounds and composite oxides may contain elements from Group 1 to Group 3 of the periodic table or halogen elements mainly to modify the amorphous structure. Transition metals may also be included.
[0023]
Among the above negative electrode materials, an amorphous composite oxide mainly composed of tin is preferable, and is represented by the following general formula (1) or (2).
SnM ¹ _a O _t general formula (1)
In the formula, M ¹ represents two or more elements selected from Al, B, P, Si, Ge, Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements in the periodic table, and a is 0. .2 represents a number of 2 or less, and t represents a number of 1 or more and 6 or less.
[0024]
Sn _x T _1-x M ¹ _a O _t General formula (2)
In the formula, T represents a transition metal metal and represents V, Ti, Fe, Mn, Co, Ni, Zn, W, or Mo. x represents a number of 0.1 or more and 0.9 or less. M ¹ , a, and t are the same as those in the general formula (1).
[0025]
Among the compounds of the general formula (1), the following compounds of the general formula (3) are more preferable.
SnM ² _b O _t general formula (3)
In the formula, M ² represents two or more elements selected from Al, B, P, Ge, Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements in the periodic table, and b is 0.2. The number is 2 or less, and t is 1 or more and 6 or less.
[0026]
Among the compounds of the general formula (3), the following compounds of the general formula (4) are more preferable.
SnM ³ _c M ⁴ _d O _t General formula (4)
In the formula, M ³ represents at least one of Al, B, P and Ge, M ⁴ represents at least one of Group 1 element, Group 2 element, Group 3 element and halogen element in the periodic table, c Is a number of 0.2 or more and 2 or less, d is a number of 0.01 or more and 1 or less, 0.2 <c + d <2, and t is a number of 1 or more and 6 or less.
[0027]
The amorphous composite oxide of the present invention can employ either a firing method or a solution method, but the firing method is more preferable. In the firing method, it is preferable to obtain an amorphous composite oxide by thoroughly mixing oxides or compounds of the elements described in the general formula (1) and then firing.
[0028]
As firing conditions, the temperature rise rate is preferably 5 ° C. or more and 200 ° C. or less per minute, the firing temperature is preferably 500 ° C. or more and 1500 ° C. or less, and the firing time is 1 hour. It is preferable that it is 100 hours or less. Further, the rate of temperature decrease is preferably 2 ° C. or more and 10 ⁷ ° C. or less per minute.
The rate of temperature increase in the present invention is the average rate of temperature rise from “50% of the firing temperature (indicated in ° C.)” to “80% of the firing temperature (indicated in ° C.)”. It is the average rate of temperature drop from reaching “80% of the firing temperature (indicated by ° C.)” to “50% of the firing temperature (expressed in ° C)”
The temperature lowering may be cooled in a firing furnace, or taken out of the firing furnace and cooled, for example, in water. In addition, a super rapid cooling method such as the gun method, the Hammer-Anvil method, the slap method, the gas atomizing method, the plasma spray method, the centrifugal quenching method, and the melt drag method described on page 217 of ceramics processing (Gihodo Publishing 1987) can also be used. Moreover, you may cool using the single roller method of a new glass handbook (Maruzen 1991) 172 page, and the double roller method. In the case of a material that melts during firing, the fired product may be continuously taken out while supplying raw materials during firing. In the case of a material that melts during firing, it is preferable to stir the melt.
[0029]
The firing gas atmosphere is preferably an atmosphere having an oxygen content of 5% by volume or less, and more preferably an inert gas atmosphere. Examples of the inert gas include nitrogen, argon, helium, krypton, and xenon. The most preferred inert gas is pure argon.
[0030]
As for the average particle size of the compound shown by this invention, 0.1-60 micrometers is preferable. More specifically, it is preferable that the average particle diameter is 0.7 to 25 μm, and 60% or more of the total volume is 0.5 to 30 μm. The volume occupied by the particle group having a particle size of 1 μm or less of the negative electrode active material of the present invention is 30% or less of the total volume, and the volume occupied by the particle group having a particle size of 20 μm or more is 25% or less of the total volume. Is preferred. Needless to say, the particle size of the material used does not exceed the thickness of the mixture on one side of the negative electrode.
To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill, a sieve, or the like is used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle size, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet.
The average particle diameter is a median diameter of primary particles, and is measured by a laser diffraction type particle size distribution measuring apparatus.
[0031]
Although the example of the negative electrode material of this invention is shown below, this invention is not limited to these.
SnAl _0.4 B _0.5 P _0.5 K _0.1 O _3.65 , SnAl _0.4 B _0.5 P _0.5 Na _0.2 O _3.7 ,
_{SnAl 0.4 B 0.3 P 0.5 Rb 0.2} O 3.4, SnAl 0.4 B 0.5 P 0.5 Cs 0.1 O 3.65,
SnAl _0.4 B _0.5 P _0.5 K _0.1 Ge _0.05 O _3.85 , SnAl _0.4 B _0.5 P _0.5 K _0.1 Mg _0.1 Ge _0.02 O _3.83, SnAl _0.4 B _0.4 P _0.4 O _3.2 , SnAl _0.3 B _0.5 P _0.2 O _2.7 ,
SnAl _0.3 B _0.5 P _0.2 O _2.7 , SnAl _0.4 B _0.5 P _0.3 Ba _0.08 Mg _0.08 O _3.26 , SnAl _0.4 B _0.4 P _0.4 Ba _0.08 O _3.28 , SnAl _0.4 B _0.5 P _0.5 O _3.6 , SnAl _0.4 B _0.5 P _0.5 Mg _0.1 O _3.7
[0032]
SnAl _0.5 B _0.4 P _0.5 Mg _0.1 F _0.2 O _3.65 , SnB _0.5 P _0.5 Li _0.1 Mg _0.1 F _0.2 O _3.05 , SnB _0.5 P _0.5 K _0.1 Mg _0.1 F _0.2 O _3.05 , SnB _0.5 P _0.5 K _0.05 Mg _0.05 F _0.1 O _3.03 , SnB _0.5 P _0.5 K _0.05 Mg _0.1 F _0.2 O _3.03 , SnAl _0.4 B _0.5 P _0.5 Cs _0.1 Mg _0.1 F _0.2 O _3.65 , SnB _0.5 P _0.5 Cs _0.05 Mg _0.05 F _0.1 O _3.03 , SnB _0.5 P _0.5 Mg _0.1 F _0.1 O _3.05 , SnB _0.5 P _0.5 Mg _0.1 F _0.2 O ₃ , SnB _0.5 P _0.5 Mg _0.1 F _0.06 O _3.07 , SnB _0.5 P _0.5 Mg _0.1 F _0.14 O _3.03 , SnPBa _0.08 O _3.58 , SnPK _0.1 O _3.55 , SnPK _0.05 Mg _{0.05 O 3.58, SnPCs 0.1 O 3.55} , SnPBa 0.08 F 0.08 O 3.54, SnPK 0.1 Mg 0.1 F 0.2 O 3.55, SnPK 0.05 Mg 0.05 F 0.1 O 3.53, SnPCs 0.1 Mg 0.1 F 0.2 O 3.55, Sn _{Cs 0.05 Mg 0.05 F 0.1 O 3.53} ,
[0033]
Sn _1.1 Al _0.4 B _0.2 P _0.6 Ba _0.08 F _0.08 O _3.54 , Sn _1.1 Al _0.4 B _0.2 P _0.6 Li _0.1 K _0.1 Ba _0.1 F _0.1 O _3.65 , Sn _1.1 Al _0.4 B _0.4 P _0.4 Ba _0.08 O _3.34
Sn _1.1 Al _0.4 PCs _0.05 O _4.23 , Sn _1.1 Al _0.4 PK _0.05 O _4.23 , Sn _1.2 Al _0.5 B _0.3 P _0.4 Cs _0.2 O _3.5 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 O _3.68 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Ba _0.08 F _0.08 O _3.64 , Sn _1.2 Al _0.4 B _0.2 P _0.6 Mg _0.04 Ba _0.04 O _3.68 , Sn _1.2 Al _0.4 B _0.3 P _0.5 Ba _0.08 O _3.58 , Sn _1.3 Al _0.3 B _0.3 P _0.4 Na _0.2 O _3.3 , Sn _1.3 Al _0.2 B _0.4 P _0.4 Ca _0.2 O _3.4 , Sn _1.3 Al _0.4 B _0.4 P _0.4 Ba _0.2 O _3.6 , Sn _1.4 Al _0.4 PK _0.2 O _4.6 , Sn _1.4 Al _0.2 Ba _0.1 PK _0.2 O _4.45 , Sn _1.4 Al _0.2 Ba _0.2 PK _0.2 O _4.6 , Sn _1.4 Al _0.4 Ba _0.2 PK _0.2 Ba _0.1 F _0.2 O _4.9 , Sn _1.4 Al _0.4 PK _0.3 O _4.65 , Sn _1.5 Al _0.2 PK _0.2 O _4.4 , Sn _1.5 Al _0.4 PK _0.1 O _4.65 , Sn _1.5 Al _0.4 PCs _{0 .05} O _4.63 , Sn _1.5 Al _0.4 PCs _0.05 Mg _0.1 F _0.2 O _4.63
[0034]
SnSi _0.5 Al _0.1 B _0.2 P _0.1 Ca _0.4 O _3.1 , SnSi _0.4 Al _0.2 B _0.4 O _2.7 ,
SnSi _0.5 Al _0.2 B _0.1 P _0.1 Mg _0.1 O _2.8 , SnSi _0.6 Al _0.2 B _0.2 O _2.8 ,
SnSi _0.5 Al _0.3 B _0.4 P _0.2 O _3.55 , SnSi _0.5 Al _0.3 B _0.4 P _0.5 O _4.30 ,
_{SnSi 0.6 Al 0.1 B 0.1 P 0.3} O 3.25, SnSi 0.6 Al 0.1 B 0.1 P 0.1 Ba 0.2 O 2.95. SnSi _0.6 Al _0.1 B _0.1 P _0.1 Ca _0.2 O _2.95 , SnSi _0.6 Al _0.4 B _0.2 Mg _0.1 O _3.2 , SnSi _0.6 Al _0.1 B _0.3 P _0.1 O _3.05 , SnSi _0.6 Al _0.2 Mg _0.2 O _2.7 , SnSi _0.6 Al _0.2 Ca _0.2 O _2.7 , SnSi _0.6 Al _0.2 P _0.2 O ₃ ,
SnSi _0.6 B _0.2 P _0.2 O ₃ , SnSi _0.8 Al _0.2 O _2.9 , SnSi _0.8 Al _0.3 B _0.2 P _0.2 O _3.85 , SnSi _0.8 B _0.2 O _2.9 , SnSi _0.8 Ba _0.2 O _2.8 , SnSi _0.8 Mg _0.2 O _2.8 , SnSi _0.8 Ca _0.2 O _2.8 , SnSi _0.8 P _0.2 O _3.1
[0035]
Sn _0.9 Mn _0.3 B _0.4 P _0.4 Ca _0.1 Rb _0.1 O _2.95 , Sn _0.9 Fe _0.3 B _0.4 P _0.4 Ca _0.1 Rb _0.1 O _2.95 , Sn _0.8 Pb _0.2 Ca _0.1 P _0.9 O _3.35 , Sn _0.3 Ge _0.7 Ba _0.1 P _0.9 O _{3.35, Sn 0.9 Mn 0.1 Mg 0.1} P 0.9 O 3.35, Sn 0.2 Mn 0.8 Mg 0.1 P 0.9 O 3.35, Sn 0.7 Pb 0.3 Ca 0.1 P 0.9 O 3.35, Sn 0.2 Ge 0.8 Ba 0.1 P 0.9 O 3.35.
[0036]
The chemical formula of the compound obtained by firing can be calculated from the weight difference between the powders before and after firing as an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method.
[0037]
The amount of light metal inserted into the negative electrode material of the present invention may be close to the precipitation potential of the light metal, but for example, it is preferably 50 to 700 mol%, particularly preferably 100 to 600 mol% per negative electrode material. It is preferable that the release amount be larger than the insertion amount. The light metal insertion method is preferably an electrochemical, chemical or thermal method. The electrochemical method is preferably a method in which a light metal contained in the positive electrode active material is inserted electrochemically or a method in which the light metal or an alloy thereof is directly inserted electrochemically. Chemical methods include mixing with light metals, contact, or reacting with an organic metal such as butyllithium. Electrochemical methods and chemical methods are preferred. The light metal is particularly preferably lithium or lithium ion.
[0038]
Various elements can be included in the negative electrode material of the present invention. For example, it may contain a dopant of a lanthanoid metal (Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg) or various compounds that increase electron conductivity (for example, Sb, In, Nb compounds). . The amount of the compound to be added is preferably 0 to 5 mol%.
[0039]
The surface of the positive electrode active material or negative electrode material of the oxide used in the present invention can be coated with an oxide having a chemical formula different from that of the positive electrode active material or negative electrode material used. The surface oxide is preferably an oxide containing a compound that dissolves both acidic and alkaline. Furthermore, a metal oxide having high electron conductivity is preferable. For example, PbO ₂ , Fe ₂ O ₃ , SnO ₂ , In ₂ O ₃ , ZnO, or the like or a dopant (for example, a metal having a different valence in the oxide, a halogen element, or the like) is preferably included in these oxides. . Particularly preferred are SiO ₂ , SnO ₂ , Fe ₂ O ₃ , ZnO, and PbO ₂ .
[0040]
The amount of the surface-treated metal oxide is preferably 0.1 to 10% by weight per the positive electrode active material or the negative electrode material. Moreover, 0.2 to 5 weight% is especially preferable, and 0.3 to 3 weight% is the most preferable.
[0041]
In addition, the surface of the positive electrode active material or the negative electrode material can be modified. For example, the surface of the metal oxide may be treated with an esterifying agent, treated with a chelating agent, treated with a conductive polymer, polyethylene oxide, or the like.
In addition, the surface of the negative electrode material can be modified. For example, the treatment may be performed by providing an ion conductive polymer or a polyacetylene layer. Further, the positive electrode active material and the negative electrode material may be subjected to a purification step such as washing with water.
[0042]
As the electrode mixture, a conductive agent, a binder, a filler, a dispersant, an ionic conductive agent, a pressure enhancer, and other various additives can be used.
The conductive agent may be anything as long as it is an electron conductive material that does not cause a chemical change in the constructed battery. Usually, graphite such as natural graphite (scale-like graphite, scale-like graphite, earth-like graphite), artificial graphite, carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, Conductive fibers such as carbon fibers and metal fibers, metal powders such as copper, nickel, aluminum and silver, conductive whiskers such as zinc oxide and potassium titanate, conductive metal oxides such as titanium oxide or polyphenylene derivatives An organic conductive material such as can be included alone or as a mixture thereof. Among these conductive agents, acetylene black and a combination of graphite and acetylene black are particularly preferable. When preparing an aqueous dispersion, it is preferable to use a conductive agent previously dispersed in water.
Although the addition amount of a electrically conductive agent is not specifically limited, 1 to 50 weight% is preferable and especially 1 to 30 weight% is preferable. In the case of carbon or graphite, 2 to 15% by weight is particularly preferable.
[0043]
As the binder used for the mixture layer and the active material-free layer, a polysaccharide, a thermoplastic resin, and a polymer having rubber elasticity, or a mixture thereof can be used. Preferred examples include starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, and ethylene-propylene-diene terpolymer. Mention may be made of (EPDM), sulfonated EPDM, styrene butadiene rubber, polybutadiene, fluororubber and polyethylene oxide. Moreover, when using the compound containing a functional group which reacts with lithium like a polysaccharide, it is preferable to add the compound like an isocyanate group and to deactivate the functional group, for example. The amount of the binder added is not particularly limited, but is preferably 1 to 50% by weight, and particularly preferably 2 to 30% by weight. The distribution of the binder in the mixture may be uniform or non-uniform. A preferable binder in the present invention is a polymer having a decomposition temperature of 300 ° C. or higher. For example, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) , Vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer (ETFE resin), polychlorotrifluoroethylene (PCTFE), vinylidene fluoride- Pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene Tetrafluoroethylene copolymer, vinylidene fluoride - perfluoromethylvinylether - can be exemplified tetrafluoroethylene copolymer.
[0044]
Any filler can be used as long as it is a fibrous material that does not cause a chemical change in the constructed battery. Usually, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. Although the addition amount of a filler is not specifically limited, 0 to 30 weight% is preferable.
[0045]
As the ionic conductive agent, those known as inorganic and organic solid electrolytes can be used, and details are described in the section of the electrolytic solution. A pressure enhancer is a compound that increases the internal pressure described later, and carbonate is a typical example.
[0046]
The electrolyte is generally composed of a solvent and a lithium salt (anion and lithium cation) dissolved in the solvent. Examples of the solvent include propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, methyl formate, methyl acetate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, ethyl monoglyme, phosphoric acid triester, trimethoxymethane, dioxolane derivative, sulfolane, 3-methyl-2-oxazolidinone, propylene carbonate derivative, tetrahydrofuran derivative, And aprotic organic solvents such as ethyl ether and 1,3-propane sultone. Used in admixture et of one or two or more kinds. Examples of lithium salt cations dissolved in these solvents include ClO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ CO ₂ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , and (CF ₃ SO ₂ ) ₂ N ⁻ , B ₁₀ Cl ₁₀ ²⁻ , (1,2-dimethoxyethane) ₂ ClO ₄ ⁻ , lower aliphatic carboxylate ion, AlCl ₄ ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , chloroborane compound Anions and tetraphenylborate ions can be mentioned, and one or more of these can be used. Among these, it is preferable to include a cyclic carbonate and / or an acyclic carbonate. For example, it is preferable to include diethyl carbonate, dimethyl carbonate, or methyl ethyl carbonate. Moreover, it is preferable to include ethylene carbonate and propylene carbonate. In addition to ethylene carbonate, an electrolytic solution in which propylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate or diethyl carbonate is appropriately mixed contains LiCF ₃ SO ₃ , LiClO ₄ , LiBF ₄ and / or LiPF ₆ . An electrolyte is preferred. In those supporting salts, it is particularly preferable to include LiPF ₆ .
[0047]
The amount of these electrolytes added to the battery is not particularly limited, but a necessary amount can be used depending on the amount of the positive electrode active material and the negative electrode material and the size of the battery.
The concentration of the supporting electrolyte is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution.
[0048]
In addition to the electrolytic solution, the following solid electrolyte can be used in combination. The solid electrolyte is classified into an inorganic solid electrolyte and an organic solid electrolyte. Well-known inorganic solid electrolytes include Li nitrides, halides, oxyacid salts, and the like. Among _{them, Li 3 N, LiI, Li} 5 NI 2, Li 3 N-LiI-LiOH, Li 4 SiO 4, Li 4 SiO 4 -LiI-LiOH, x Li 3 PO 4 - (1-x) Li 4 SiO ₄ , Li ₂ SiS ₃ , phosphorus sulfide compounds and the like are effective.
[0049]
In the organic solid electrolyte, a polyethylene oxide derivative or a polymer containing the derivative, a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ion dissociation group, a mixture of a polymer containing an ion dissociation group and the above aprotic electrolyte, phosphoric acid A polymer matrix material containing an ester polymer and an aprotic polar solvent is effective. Furthermore, there is a method of adding polyacrylonitrile to the electrolytic solution. A method of using an inorganic and organic solid electrolyte in combination is also known.
[0050]
Further, other compounds may be added to the electrolyte for the purpose of improving discharge and charge / discharge characteristics. For example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylenediamine, n-glyme, hexaphosphoric acid triamide, nitrobenzene derivative, sulfur, quinoneimine dye, N-substituted oxazolidinone and N, N'-substituted imidazolidinone, ethylene glycol dialkyl ether , Quaternary ammonium salt, polyethylene glycol, pyrrole, 2-methoxyethanol, AlCl ₃ , monomer of conductive polymer electrode active material, triethylenephosphoramide, trialkylphosphine, morpholine, aryl compound having carbonyl group, Crown ethers such as 12-crown-4, hexamethylphosphoric triamide and 4-alkylmorpholine, bicyclic tertiary amine, oil, quaternary phosphonium salt, tertiary sulfoni Or the like can be mentioned a salt-free.
[0051]
In order to make the electrolyte nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolyte. In addition, carbon dioxide gas can be included in the electrolyte in order to make it suitable for high-temperature storage.
[0052]
Further, the mixture of the positive electrode and the negative electrode can contain an electrolytic solution or an electrolyte. For example, a method in which the ion conductive polymer, nitromethane, or an electrolytic solution is included is known.
[0053]
As the separator, an insulating microporous thin film having a large ion permeability and a predetermined mechanical strength is used. Moreover, it is preferable to have a function of closing the hole at 80 ° C. or higher and increasing the resistance. Sheets and nonwoven fabrics made from olefin polymers such as polypropylene and / or polyethylene or glass fibers are used because of their organic solvent resistance and hydrophobicity. As the pore diameter of the separator, a range generally used as a battery separator is used. For example, 0.01 to 10 μm is used. The thickness of the separator is generally used within the range of battery separators. For example, 5 to 300 μm is used. In the production of the separator, after the synthesis of the polymer, the pores may be formed by a dry method, a stretching method, a solution, a solvent removing method, or a combination thereof.
[0054]
The current collector of the electrode active material may be anything as long as it is an electronic conductor that does not cause a chemical change in the constructed battery. For example, in addition to stainless steel, nickel, aluminum, titanium, carbon, and the like as materials for the positive electrode, a material obtained by treating the surface of aluminum or stainless steel with carbon, nickel, titanium, or silver is used. In particular, aluminum or an aluminum alloy is preferable. For the negative electrode, in addition to stainless steel, nickel, copper, titanium, aluminum, carbon, etc., the surface of copper or stainless steel treated with carbon, nickel, titanium, or silver, Al-Cd alloy, etc. are used. It is done. In particular, copper or a copper alloy is preferable. Oxidizing the surface of these materials is also used. Further, it is desirable to make the current collector surface uneven by surface treatment. As the shape, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like are used in addition to the foil. The thickness is not particularly limited, but a thickness of 1 to 500 μm is used.
[0055]
The shape of the battery can be applied to any of sheets, cylinders, flats and corners.
The positive electrode active material and the negative electrode material mixture are mainly used after being applied (coated), dried and compressed on the current collector. As a coating method, a general method can be used. Examples thereof include a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion method, a curtain method, a gravure method, a bar method, a dip method, and a squeeze method. Of these, blade method, knife method and extrusion method are preferred. The application is preferably performed at a speed of 0.1 to 100 m / min. Under the present circumstances, the surface state of a favorable coating layer can be obtained by selecting the said application | coating method according to the solution physical property and dryness of a mixture. The application may be performed one side at a time or simultaneously on both sides. The application may be continuous, intermittent, or striped. Although the thickness, length, and width of the coating layer are determined by the size of the battery, the thickness of the coating layer on one side is particularly preferably 1 to 2000 μm in a compressed state after drying.
[0056]
As a method for drying or dehydrating the sheet, a generally adopted method can be used. In particular, it is preferable to use hot air, vacuum, infrared rays, far infrared rays, electron beams and low-humidity air alone or in combination. The temperature is preferably in the range of 80 to 350 ° C, particularly preferably in the range of 100 to 250 ° C. The water content is preferably 2000 ppm or less for the entire battery, and preferably 500 ppm or less for each of the positive electrode mixture, the negative electrode mixture and the electrolyte in terms of cycleability.
As a sheet pressing method, a generally adopted method can be used, and a mold pressing method and a calendar pressing method are particularly preferable. Although a press pressure is not specifically limited, 0.2-3 t / cm < ² > is preferable. The press speed of the calendar press method is preferably 0.1 to 50 m / min. The pressing temperature is preferably room temperature to 200 ° C. The ratio of the width of the positive electrode sheet to the negative electrode sheet is preferably 0.9 to 1.1. In particular, 0.95-1.0 is preferable. The content ratio of the positive electrode active material and the negative electrode material varies depending on the compound type and the mixture formulation, and thus cannot be limited.
[0057]
After the mixture sheet and the separator are overlapped with each other, the sheets are rolled, folded, inserted into the can, the can and the sheet are electrically connected, the electrolyte is injected, and the sealing plate is attached. To form a battery can. At this time, the safety valve can be used as a sealing plate. In addition to the safety valve, various conventionally known safety elements may be provided. For example, a fuse, bimetal, PTC element, or the like is used as the overcurrent prevention element. In addition to the safety valve, as a countermeasure against the increase in internal pressure of the battery can, a method of cutting the battery can, a method of cracking the gasket, a method of cracking the sealing plate, or a method of cutting the lead plate can be used. Further, the charger may be provided with a protection circuit incorporating a countermeasure against overcharge or overdischarge, or may be connected independently. In addition, as a measure against overcharging, a method of cutting off current by increasing the battery internal pressure can be provided. At this time, a compound for increasing the internal pressure can be contained in the mixture or the electrolyte. Examples of the compound raising the internal pressure, and carbonates such as _{Li 2 CO 3, LiHCO 3,} Na 2 CO 3, NaHCO 3, CaCO 3, MgCO 3 and the like.
For the can and lead plate, a metal or alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum, or alloys thereof are used. As a method for welding the cap, the can, the sheet, and the lead plate, a known method (eg, direct current or alternating current electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.
[0058]
The use of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when mounted on an electronic device, a color notebook computer, a monochrome notebook computer, a sub-notebook computer pen input computer, a pocket (palmtop) computer, a notebook Type word processor, pocket word processor, electronic book player, mobile phone, cordless phone, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini-disc, Electric shaver, electronic translator, car phone, transceiver, power tool, electronic notebook, calculator, memory card, tape recorder, radio, backup power supply, memory card, etc. Others for consumer use include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, irons, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with another secondary battery, a solar cell, or a primary battery.
[0059]
The preferred combination of the present invention is preferably a combination of the above-mentioned chemical materials and preferred battery components, and in particular, as a positive electrode active material, Li _x CoO ₂ , Li _x NiO ₂ , Li _x MnO ₂ , Li _x Mn _It contains at least one compound selected from ₂ O ₄ (where x = 0.05 to 1.2) and also contains acetylene black as a conductive agent. The positive electrode current collector is made of stainless steel or aluminum and has a net, sheet, foil, or lath shape. As a negative electrode material, lithium metal, lithium alloy (Li—Al), carbonaceous compound, oxide (LiCoVO ₄ , SnO ₂ , SnO, SiO, GeO ₂ , GeO, SnSiO ₃ , SnSi _0.3 Al _0.1 B _0.2 P _0.3 O _3.2 ), Sulfide (TiS ₂ , SnS ₂ , SnS, GeS ₂ , GeS) and the like are preferably used. The negative electrode current collector is made of stainless steel or copper and has the shape of a net, sheet, foil, lath or the like. In the mixture used together with the positive electrode active material or the negative electrode material, a carbon material such as acetylene black or graphite may be mixed as an electron conductive agent. As the binder, fluorine-containing thermoplastic compounds such as polyvinylidene fluoride and polyfluoroethylene, polymers containing acrylic acid, elastomers such as styrene butadiene rubber and ethylene propylene terpolymer can be used alone or in combination. The electrolyte includes ethylene carbonate, a combination of cyclic and non-cyclic carbonates such as diethyl carbonate and dimethyl carbonate, and ester compounds such as ethyl acetate. The supporting electrolyte includes LiPF ₆ , and further includes LIBF ₄ and LiCF _3. It is preferable to use a mixture of lithium salts such as SO ₃ . Further, as the separator, polypropylene or polyethylene alone or a combination thereof is preferable. The form of the battery may be any of a cylinder, a flat shape, and a square shape. It is preferable that the battery is provided with means (eg, an internal pressure relief type safety valve, a current cutoff type safety valve, a separator that increases resistance at high temperatures) that can ensure safety against malfunction.
[0060]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples unless it exceeds the gist of the invention.
Example-1
86 parts by weight of SnB _0.2 P _0.5 K _0.1 Mg _0.1 Ge _0.1 O _2.8 as a negative electrode active material, 3 parts by weight of acetylene black and 6 parts by weight of graphite are mixed as a conductive agent, and polyvinylidene fluoride is further added as a binder. 4 parts by weight and 1 part by weight of carboxymethylcellulose were added and kneaded using water as a medium to obtain a negative electrode mixture slurry. The slurry was coated on both sides of a copper foil having a thickness of 10 μm using an extrusion type coating machine, dried and then compression-molded by a calendar press machine, and a strip-like negative electrode sheet (82 μm thick, 55 mm wide, 490 mm long) (2 )created.
87 parts by weight of LiCoO ₂ as a positive electrode active material, 3 parts by weight of acetylene black and 6 parts by weight of graphite as a conductive agent are mixed, and 3 parts by weight of Nipol 820B (manufactured by Zeon Corporation) and 1 part by weight of carboxymethyl cellulose as a binder. And kneaded with water as a medium to obtain a positive electrode mixture slurry. Further, 94 parts by weight of a powder mixture obtained by mixing electron conductive particles and non-electron conductive particles at a ratio shown in Table 1, 4 parts by weight of polyvinylidene fluoride, and 2 parts by weight of carboxymethyl cellulose were kneaded using water as a medium. A slurry of a substance-free layer was obtained. The slurry was coated on both sides of an aluminum foil having a thickness of 20 μm in the layer configuration shown in Table 1 using an extrusion coater, dried, and then compression-molded by a calendar press to have a thickness of 260 μm, a width of 53 mm, and a length. A 445 mm strip-shaped positive electrode sheet (1) was prepared.
[0061]
Each of the negative electrode sheet (2) and the positive electrode sheet (1) was welded to a lead plate made of nickel and aluminum at each end, and then heat-treated at 230 ° C. for 1 hour in dry air having a dew point of −40 ° C. or less. The heat treatment was performed using a far infrared heater. Further, a heat-treated positive electrode sheet (1), a microporous polyethylene / polypropylene film separator (3), a heat-treated negative electrode sheet (2) and a separator (3) are laminated in this order, and this is wound in a spiral shape. did. The state of cracking of the positive electrode sheet and dropping of the mixture was observed during winding.
This wound body was stored in a nickel-plated iron-bottomed cylindrical battery can (4) that also served as a negative electrode terminal. Further, 1 mol / liter LiPF ₆ (2: 8 weight ratio mixture of ethylene carbonate and diethyl carbonate) was injected into the battery can as an electrolyte. A battery lid (5) having a positive electrode terminal was caulked through a gasket (6) to produce a cylindrical battery having a height of 65 mm and an outer diameter of 18 mm. In addition, the positive electrode terminal (5) positive electrode sheet (1) and the battery can (4) were previously connected to the negative electrode sheet by a lead terminal. (7) is a safety valve. The battery was charged to 4.2 V at 1 mA / cm ² and then discharged to 2.8 V. Discharge current was calculated discharge current dependency taking the ratio of the two is performed for two types of ^{1mA / cm 2, 5mA / cm} 2. Table 1 shows the results of the cracking of the positive electrode sheet and the discharge current dependency.
[0062]
[Table 1]

[0063]
【The invention's effect】
As is clear from the results in Table 1, the battery of the present invention in which the active material non-containing layer is provided on the positive electrode is improved in the cracking of the positive electrode at the time of winding and the active material non-containing layer is provided in the uppermost layer in terms of discharge current dependency. Better than that.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a general cylindrical battery.
[Explanation of symbols]
1. 1. Positive electrode sheet 2. negative electrode sheet Separator 4. Battery can 5. Battery lid 6. Gasket 7. safety valve

Claims (12)

A positive electrode sheet formed by applying a mixture containing a positive electrode active material which is a lithium-containing transition metal oxide; a negative electrode sheet formed by applying a mixture containing a negative electrode material capable of occluding and releasing lithium; and lithium metal In an electrolyte comprising a non-aqueous electrolyte containing a salt, the positive electrode sheet comprises an electron conductive particle, a non-electron conductive particle, and a positive electrode active material-free layer containing a binder as a lithium-containing transition metal oxide. Between the electron-containing particles and the non-electron-conductive particles contained in the mixture containing a certain positive electrode active material or in the lowermost layer of the mixture, and contained in the positive electrode active material non-containing layer A nonaqueous secondary battery using a battery having a ratio of 1:99 to 50: 50% by weight . The ratio of the coating amount of the mixture layer above the positive electrode active material non-containing layer and the mixture layer below is 10: 0 to 1: 9. Water secondary battery. The nonaqueous secondary battery according to claim 1 , wherein the electron conductive particles are at least one compound selected from carbon blacks, graphites, and metal powders . 2. The non-conductive particle according to claim 1, wherein the non-conductive particles are at least one compound selected from the group consisting of aluminum oxide, titanium oxide, zirconium oxide, silicon dioxide, zirconium silicate, mica, kaolinite, smectite, and pyrophyllite. Water secondary battery. 2. The non-aqueous secondary battery according to claim 1 , wherein the binder is at least one polymer selected from the group consisting of a polysaccharide having a decomposition temperature of 300 ° C. or higher, a thermoplastic resin, and a polymer having rubber elasticity . 6. The non-aqueous secondary battery according to claim 1, comprising at least one lithium-containing transition metal composite oxide as the positive electrode active material . The electrolyte solution which comprises the electrolyte which consists of this non-aqueous electrolyte containing this lithium metal salt is a solvent containing a cyclic carbonate and / or a non-cyclic carbonate, The any one of Claim 1 to 6 characterized by the above-mentioned. Non-aqueous secondary battery. Nonaqueous consisting electrolyte lithium metal salt constituting the electrolyte is non-aqueous secondary battery according to any one of claims 1 to 7, characterized in that it comprises a LiPF ₆ containing the lithium metal salt. The nonaqueous secondary battery according to any one of claims 1 to 8, wherein the negative electrode material is a metal or a metalloid oxide . A layer mainly composed of a metal or metalloid oxide of the negative electrode material, a metal from the Periodic Table 13 Group 15 of, in claim 9, characterized in that a layer comprising at least one oxide of a metalloid element The non-aqueous secondary battery as described. The non-aqueous secondary battery, wherein the negative electrode material according to claim 10 is a composite oxide of the following general formula (1).
SnM ¹ aOt General formula (1)
Where M ¹ Represents two or more elements selected from Al, B, P, Si, Ge, Group 1 elements, Group 2 elements, Group 3 elements, and halogen elements in the periodic table, and a is 0.2 or more, 2 In the following numbers, t represents a number of 1 or more and 6 or less. The composite oxide containing tin is a composite oxide represented by the following general formula (4): The non-aqueous secondary battery according to 1.
SnM ³ cM ⁴ dOt General formula (4)
Where M ³ Is at least one of Al, B, P, Ge, M ⁴ Represents at least one of group 1 element, group 2 element, group 3 element and halogen element in the periodic table, c is a number of 0.2 or more and 2 or less, and d is 0.01 or more and 1 or less. In terms of numbers, 0.2 <c + d <2, t is a number from 1 to 6, inclusive.

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