JP2010277806A - Nonaqueous secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery having: a configuration prepared in one with a larger expansion and contraction degree upon charging and discharging out of a positive electrode plate and a negative electrode plate, for performing function which suppresses the expansion and construction of the one with the larger expansion and contraction degree; with high safety by alleviating stress caused by expansion and contraction of the electrode plates upon charging and discharging the nonaqueous secondary battery, and by preventing breakage or buckling of the electrode plates upon charging and discharging. <P>SOLUTION: An electrode group 10 configured with a cathode plate 4 with a positive electrode mixture coating material coated on a positive electrode collector 1 and with positive electrode mixture layers 2a, 2b formed, a negative electrode plate 8 with a negative electrode mixture coating material coated on a negative electrode collector 5 and with negative electrode mixture layers 6a, 6b formed on the negative electrode collector 5, with a separator 9 intervened between them and spirally wound, further has a configuration with the expansion and contraction suppressing function for suppressing expansion and contraction in either of the positive electrode plate 4 or the negative electrode plate 8 with the larger expansion and contraction degree upon charging and discharging. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a non-aqueous secondary battery represented by a lithium ion secondary battery, and more particularly to a non-aqueous secondary battery excellent in safety.

In recent years, lithium ion secondary batteries, which are widely used as power sources for portable electronic devices, use a carbonaceous material capable of occluding and releasing lithium for the negative electrode, and a composite of a transition metal such as LiCoO ₂ and lithium for the positive electrode. An oxide is used as an active material, thereby realizing a lithium ion secondary battery having a high potential and a high discharge capacity. However, with the recent increase in functionality of electronic devices and communication devices, it is desired to further increase the capacity of lithium ion secondary batteries.

  Here, as an electrode plate that is a power generation element for realizing a high-capacity lithium ion secondary battery, an electrode mixture paint obtained by coating each constituent material on both the positive electrode plate and the negative electrode plate is placed on the current collector. After applying and drying, a method of compressing to the specified thickness by pressing or the like is used. By filling and pressing more active material, the active material density becomes higher and further increase in capacity is possible. It becomes. Further, an electrode group in which the above-described positive electrode plate and negative electrode plate are sequentially laminated via a separator or spirally wound via a separator is made of a metal such as stainless steel, nickel-plated iron, or aluminum. In a battery case, a non-aqueous electrolyte is poured into the battery case, and then a sealing plate is hermetically fixed to the opening of the battery case to form a lithium ion secondary battery.

  By the way, while increasing capacity of non-aqueous secondary batteries typified by lithium ion batteries, safety measures should be emphasized. In particular, the positive and negative plates are rapidly connected to the non-aqueous secondary battery due to an internal short circuit. There is a strong demand for improvement in the safety of non-aqueous secondary batteries, because there is a risk of excessive temperature rise and thermal runaway. In particular, a large-sized, high-power non-aqueous secondary battery has a high probability of thermal runaway, and thus a device for improving safety, such as reducing the probability of occurrence, is necessary.

  As described above, the cause of the internal short circuit of the non-aqueous secondary battery is that, as shown in FIG. 13A, in addition to foreign matters entering the non-aqueous secondary battery, The positive electrode plate 23 on which the positive electrode mixture layers 22a and 22b are formed and the negative electrode plate 26 on which the negative electrode mixture layers 25a and 25b are formed on the negative electrode current collector 24 are sandwiched through a separator 27 made of a porous insulator. It is conceivable that the electrode plate is broken or buckled by the stress applied to the electrode plate when the electrode group 28 is configured by turning, and further when the non-aqueous secondary battery is charged and discharged. More specifically, when the electrode group 28 is formed by winding in a spiral shape, tensile stress is applied to the positive electrode plate 23, the negative electrode plate 26, and the separator 27, which are constituent elements, and the elongation rate of each constituent element at this time is increased. The difference causes the fracture from the smallest elongation. In addition, when a non-aqueous secondary battery is charged / discharged, stress due to expansion / contraction of the electrode plate is applied to the electrode plate, and the positive electrode plate 23, the negative electrode plate 26 or the separator 27 has the lowest elongation rate due to repeated stress due to repeated charge / discharge. Things break preferentially.

For example, as shown in FIG. 13B, when the positive electrode plate 23 cannot follow the elongation of the negative electrode plate 26 during charging, the positive electrode plate 23 is broken (F in the figure). Even if no breakage occurs, as shown in FIG. 13C, the separator 27 is stretched due to the buckling of the negative electrode plate 26, thereby generating a portion (G in the figure) where the thickness of the separator 27 is reduced. Further, when the positive electrode plate 23 or the negative electrode plate 26 is broken before the separator 27, the broken portion of one of the electrode plates breaks through the separator 27 and the positive electrode plate 23 and the negative electrode plate 26 are short-circuited. Due to this short circuit, a large current flows, and as a result, the temperature of the non-aqueous secondary battery rises rapidly, and the non-aqueous secondary battery may run out of heat as described above.

  Therefore, in order to suppress the breakage of the positive electrode plate, as shown in FIG. 14, the positive electrode plate 33 with the positive electrode mixture layer formed on both surfaces and the negative electrode plate 34 with the negative electrode mixture layer applied on both surfaces are separated by the separator 35. In the non-aqueous secondary battery 31 in which the power generation element 32 wound in a flat shape and the non-aqueous electrolyte solution are accommodated in the battery case 36, the positive electrode combination of the first surface on the inner peripheral side of both surfaces of the positive electrode plate 33 is A method has been proposed in which the agent layer has higher flexibility (higher tensile elongation at break) than the positive electrode mixture layer on the second surface on the back side (see, for example, Patent Document 1).

  In order to improve the elongation rate of the electrode plate, a separator 43 is interposed between the positive electrode plate 41 connected to the positive electrode lead 44 and the negative electrode plate 42 connected to the negative electrode lead 45 as shown in FIG. In a non-aqueous secondary battery in which a positive electrode lead 44 is connected to the positive electrode external terminal 46, a negative electrode lead 45 is connected to the battery case 47, and a non-aqueous electrolyte is injected, Before laminating or winding up the negative electrode plate 42 and the separator 43 to be interposed between the two electrodes, the positive electrode plate is heated at a temperature higher than the recrystallization temperature of the binder and lower than its decomposition temperature. There has been proposed a method of heat-treating one or both of the electrode plate 41 and the negative electrode plate 42 (for example, see Patent Document 2).

JP 2007-103263 A Japanese Patent No. 3066161

  However, in the above-described prior art such as making the positive electrode mixture layer on the inner peripheral side of the positive electrode plate more flexible than the outer peripheral side or heat-treating the electrode plate, it is due to bending stress applied to the positive electrode plate when forming the electrode group. Although the effect of suppressing the breakage of the positive electrode plate is exhibited, it is difficult to reduce the expansion and contraction of the electrode plate when charging and discharging the non-aqueous secondary battery and to suppress the breakage or buckling of the electrode plate during charge and discharge. Had the problem of being. In addition, in the prior art of Patent Document 1 described above, two types of positive electrode mixture paints are prepared to be applied to the front and back surfaces of the positive electrode plate, and these two types of positive electrode mixture paints are applied on the positive electrode current collector. Therefore, the process for producing the positive electrode plate becomes complicated. In the prior art of Patent Document 2, an electrode group is formed by pressing the electrode plate to a specified thickness and then performing heat treatment and winding to form an electrode group. The electrode plate compressed to the specified thickness by this heat treatment causes buckling. The variation in the thickness of the electrode plate before winding becomes large. Furthermore, it may cause a problem such as a large variation in diameter of the wound electrode group.

  The present invention has been made in view of the above-described conventional problems, and has a configuration in which an expansion / contraction suppression function for suppressing expansion / contraction is provided on the one with a large expansion / contraction degree at the time of charge / discharge of the positive electrode plate and the negative electrode plate in the nonaqueous secondary battery, An object of the present invention is to provide a highly safe non-aqueous secondary battery by relaxing expansion / contraction of the electrode plate when charging / discharging the non-aqueous secondary battery and suppressing breakage or buckling of the electrode plate during charge / discharge. It is said.

In order to achieve the above object, the non-aqueous secondary battery of the present invention is a positive electrode current collector comprising a positive electrode mixture paint obtained by kneading and dispersing an active material comprising at least a lithium-containing composite oxide, a conductive material, and a binder in a dispersion medium. The negative electrode current collector is prepared by mixing a positive electrode plate having a positive electrode mixture layer deposited thereon and an active material and a binder made of a material capable of holding lithium at least in a dispersion medium. A non-aqueous electrolyte solution and a non-aqueous electrolyte encapsulated in a battery case include an electrode group formed by winding or laminating a porous insulator between a negative electrode plate formed on a negative electrode mixture layer The water-based secondary battery is characterized in that an expansion / contraction suppression function for suppressing expansion / contraction is provided on the one where the degree of expansion / contraction during charging / discharging of the positive electrode plate and the negative electrode plate is large.

  According to the non-aqueous secondary battery of the present invention, the positive and negative electrode plates at the time of charging and discharging are provided with the expansion and contraction suppressing function for suppressing the expansion and contraction on the larger degree of expansion and contraction at the time of charging and discharging. The stress applied to the positive electrode plate or negative electrode plate due to the difference in degree of expansion and contraction due to the expansion and contraction of the negative electrode plate can be relaxed, and it is possible to suppress breakage or buckling of the electrode plate, and internal short circuit caused by these It is possible to provide a highly safe non-aqueous secondary battery.

The fragmentary sectional view which shows the principal part of the electrode group for non-aqueous secondary batteries which shows the principal part of the electrode group after winding in the non-aqueous secondary battery which concerns on one embodiment of this invention The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on one embodiment of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on one Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on another Example of this invention. The perspective view which shows the principal part of the electrode group before winding in the non-aqueous secondary battery which concerns on the comparative example of this invention. 1 is a partially cutaway perspective view of a cylindrical secondary battery according to an embodiment of the present invention. (A) The fragmentary sectional view which shows the principal part of the electrode group for non-aqueous secondary batteries in a prior art example, (b) The principal part of an electrode group when the fracture | rupture of an electrode plate generate | occur | produces in the non-aqueous secondary battery in a prior art example (C) The fragmentary sectional view which shows the principal part of an electrode group in case the buckling of an electrode group generate | occur | produces in the non-aqueous secondary battery in a prior art example Cross-sectional view of a non-aqueous secondary battery in a conventional example Cross-sectional view of a non-aqueous secondary battery in a conventional example

In the first invention of the present invention, a positive electrode mixture paint obtained by kneading and dispersing at least an active material composed of a lithium-containing composite oxide, a conductive material, and a binder with a dispersion medium is applied onto a positive electrode current collector. A negative electrode mixture layer obtained by applying a negative electrode mixture coating material obtained by kneading and dispersing an active material and a binder made of a material capable of holding lithium at least in a dispersion medium on a negative electrode current collector. A non-aqueous secondary battery in which an electrode group formed by winding or laminating a porous insulator with a non-aqueous electrolyte solution is enclosed in a battery case between a positive electrode plate and a negative electrode By having a configuration with an expansion / contraction suppression function that suppresses expansion / contraction on the larger expansion / contraction degree during charging / discharging of the plate,
Reducing stress applied to the positive electrode plate or negative electrode plate due to the difference in expansion / contraction between the positive electrode plate and the negative electrode plate during charge / discharge, and suppressing internal short circuit caused by electrode plate breakage and electrode plate buckling Therefore, a highly safe non-aqueous secondary battery can be provided.

  In the second invention of the present invention, by providing the positive electrode current collector or the negative electrode current collector with the expansion / contraction suppression function, the expansion / contraction degree of one current collector between the positive electrode plate and the negative electrode plate having different expansion / contraction degrees is reduced. By reducing the difference in the degree of expansion / contraction between the two electrode plates by the current collector, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be made closer.

  In the third invention of the present invention, the positive electrode current collector or the negative electrode current collector is constituted by using an alloy having a low degree of expansion and contraction as the expansion and contraction suppressing function, so that the positive electrode is not subjected to pretreatment of the current collector. By reducing the stretchability of the current collector or the negative electrode current collector to make the positive electrode plate or the negative electrode plate difficult to stretch, it becomes possible to bring the positive and negative electrode plates closer together.

  In the fourth invention of the present invention, the positive electrode current collector or the negative electrode current collector is cured by a tempering treatment as an expansion / contraction suppression function, so that the positive electrode material is not significantly changed without significantly changing the material of the current collector. By increasing the hardness of the current collector or the negative electrode current collector to make the positive electrode plate or the negative electrode plate difficult to stretch, it becomes possible to bring the degree of expansion and contraction between the positive electrode plate and the negative electrode plate closer.

  In the fifth invention of the present invention, the thickness of the positive electrode current collector or the negative electrode current collector is increased as the expansion / contraction suppression function, so that the material change of the current collector and the pretreatment of the current collector are performed. Without increasing the thickness of the positive electrode current collector or the negative electrode current collector, the positive electrode current collector or the negative electrode current collector is made difficult to extend, and the difference in the degree of expansion and contraction between the two electrode plates is reduced. It becomes possible to make the expansion / contraction degree of a board close.

  In the sixth invention of the present invention, the positive electrode current collector or the negative electrode current collector is provided with a thick portion perpendicular to the longitudinal direction as an expansion / contraction suppression function, thereby changing the material of the current collector and Without accompanying pre-treatment of the current collector, the positive electrode current collector or the negative electrode current collector is made difficult to extend by the thick part, and the difference in the degree of expansion / contraction between the two electrode plates is reduced. It becomes possible to make the degree of elasticity close.

  In the seventh invention of the present invention, as the expansion and contraction suppressing function, the width of the positive electrode current collector or the negative electrode current collector is widened, so that the change of the material of the current collector and the pretreatment of the current collector are performed. Without increasing the width of the positive electrode current collector or the negative electrode current collector, it is possible to make the positive electrode plate and the negative electrode plate closer to each other by reducing the difference between the expansion and contraction of the two electrode plates. Become.

  In the eighth invention of the present invention, the positive electrode current collector or the negative electrode current collector is composed of an alloy having a small degree of expansion or contraction, or is cured by a tempering treatment, or thickened, or longitudinally. The thickness of the positive electrode plate and the negative electrode plate can be expanded and contracted by the current collector due to the synergistic effect of the combination of the above configurations by providing a thick portion orthogonal to the width or widening the width. By exhibiting the effect for reducing the difference in degree more effectively, it becomes possible to bring the degree of expansion and contraction between the positive electrode plate and the negative electrode plate closer.

  In the ninth aspect of the present invention, by providing the expansion / contraction suppression function in the positive electrode mixture layer or the negative electrode mixture layer, the expansion ratio of the electrode mixture layer in the positive electrode plate and the negative electrode plate having different expansion degrees is reduced, By reducing the difference in the degree of expansion / contraction between the two electrode plates by the electrode mixture layer, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be made closer.

In the tenth aspect of the present invention, the constituent material of the electrode mixture layer is greatly increased by increasing the thickness of the positive electrode mixture layer or the negative electrode mixture layer of the electrode plate having a large degree of expansion and contraction as a function of suppressing expansion and contraction. For example, by optimizing the application conditions of the electrode mixture paint, the positive electrode mixture layer or the negative electrode mixture layer is made difficult to expand by increasing the thickness of the positive electrode mixture layer or the negative electrode mixture layer. By reducing the difference in the degree of expansion / contraction between the two electrode plates by the layer, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be made closer.

  In the eleventh aspect of the present invention, the constituent material of the electrode mixture layer is constituted by reducing the active material density of the positive electrode mixture layer or increasing the active material density of the negative electrode mixture layer as an expansion and contraction suppressing function. Without significantly changing the active material density of the positive electrode mixture layer or the negative electrode mixture layer by, for example, optimizing the application conditions of the electrode mixture paint or the press conditions of the electrode mixture layer. By making the agent layer or the negative electrode mixture layer difficult to stretch and reducing the difference in the degree of expansion / contraction between the two electrode plates by the electrode mixture layer, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be made closer.

  In the twelfth aspect of the present invention, the constituent material of the electrode mixture layer is formed by increasing the porosity of the positive electrode mixture layer or the negative electrode mixture layer of the electrode plate having a large degree of expansion and contraction as a function of suppressing expansion and contraction. Without significantly changing the positive electrode mixture layer by increasing the porosity of the positive electrode mixture layer or the negative electrode mixture layer, for example, by optimizing the application conditions of the electrode mixture paint or by optimizing the press conditions of the electrode mixture layer Alternatively, the positive electrode plate and the negative electrode plate can be formed by making the negative electrode mixture layer difficult to stretch, reducing the expansion / contraction degree of the positive electrode mixture layer or the negative electrode mixture layer, and reducing the difference in expansion / contraction degree of both electrode plates by the electrode mixture layer. It becomes possible to make the degree of expansion / contraction close.

  In the thirteenth aspect of the present invention, the constituent material of the electrode mixture layer is greatly increased by increasing the hardness of the binder forming the positive electrode mixture layer or the negative electrode mixture layer as an expansion / contraction suppression function. By changing the binder of the electrode mixture layer without changing, it is difficult to extend the positive electrode mixture layer or the negative electrode mixture layer by increasing the hardness of the binder in the positive electrode mixture layer or the negative electrode mixture layer, By reducing the difference in the degree of expansion / contraction between the two electrode plates by the electrode mixture layer, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be made closer.

  In the fourteenth aspect of the present invention, as the expansion / contraction suppression function, the thickness of the positive electrode mixture layer or the negative electrode mixture layer is increased, or the active material density of the positive electrode mixture layer is decreased or the active material density of the negative electrode mixture layer is increased. The positive electrode plate and the negative electrode by the electrode mixture layer by a synergistic effect by the combination of the above constitutions by combining any two or more of increasing the porosity, increasing the porosity, or increasing the hardness of the binder By exhibiting the effect for reducing the difference in the degree of expansion / contraction between the plates more effectively, the degree of expansion / contraction between the positive electrode plate and the negative electrode plate can be brought closer to each other more effectively.

  In the fifteenth aspect of the present invention, the expansion / contraction suppression function is provided in the positive electrode current collector or the negative electrode current collector and is provided in the positive electrode mixture layer or the negative electrode mixture layer. It is possible to reduce the degree of expansion / contraction of the electrode mixture layer and to provide a stress relaxation effect more effectively by the electrode plate, thereby making it possible to bring the degree of expansion / contraction between the positive electrode plate and the negative electrode plate closer to each other.

  In the sixteenth invention of the present invention, the expansion / contraction suppression function is provided in the positive electrode current collector or the negative electrode current collector, and the positive electrode current collector layer or the negative electrode current mixture layer is provided on at least one surface of the positive electrode material mixture layer or the negative electrode material mixture layer. By forming an exposed part perpendicular to the longitudinal direction and providing an expansion / contraction relaxation function, the elasticity of the current collector is reduced and the current collector has a following effect, and the elasticity of the electrode mixture layer By making the electrode mixture layer have a follow-up effect, it becomes possible to make the expansion and contraction of the positive electrode plate and the negative electrode plate closer to each other more effectively.

In the seventeenth aspect of the present invention, the expansion / contraction suppression function is provided in the positive electrode mixture layer or the negative electrode mixture layer, and the positive electrode current collector or the negative electrode current collector is provided on at least one surface of the positive electrode mixture layer or the negative electrode mixture layer. By forming an exposed part perpendicular to the longitudinal direction and imparting an expansion / contraction relaxation function, the degree of expansion / contraction of the electrode mixture layer is reduced, and this electrode mixture layer has a follow-up effect, and stress is more effectively applied. By exhibiting the relaxation effect, it becomes possible to make the degree of expansion and contraction of the positive electrode plate and the negative electrode plate closer.

  In the eighteenth aspect of the present invention, an expansion / contraction suppression function is provided, and an expansion / contraction promotion function for accelerating expansion / contraction is provided in the direction where the expansion / contraction at the time of charging / discharging of the positive electrode plate and the negative electrode plate is small. By reducing the expansion / contraction degree of one electrode plate in the positive electrode plate and the negative electrode plate and increasing the expansion / contraction degree of the other electrode plate, it becomes possible to make the expansion degree of the positive electrode plate and the negative electrode plate closer to each other more effectively. .

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of an electrode group 10 after winding in a nonaqueous secondary battery according to an embodiment of the present invention. In the figure, an electrode group 10 for a non-aqueous secondary battery according to the present invention includes a positive electrode plate 4 and a negative electrode composite, in which a positive electrode mixture paint is applied on the positive electrode current collector 1 to form positive electrode mixture layers 2a and 2b. The negative electrode plate 8 having the negative electrode mixture layers 6a and 6b formed on the negative electrode current collector 5 by applying an agent paint on the negative electrode collector layer 6 is provided with an expansion / contraction suppressing function for suppressing expansion / contraction on the larger expansion / contraction degree. A separator 9 as a porous insulator is interposed between the positive electrode plate 4 and the negative electrode plate 8 and is wound in a spiral shape.

  Here, in the non-aqueous secondary battery represented by the lithium ion secondary battery of the present invention described above, the negative electrode mixture layer is obtained by intercalating lithium with the negative electrode plate 8 during charging as shown in FIG. 6a, 6b expands the negative electrode plate 8 due to expansion, the positive electrode plate 4 expands at this time C, and lithium is deintercalated from the negative electrode plate 8 during discharge, so that the negative electrode mixture layer 6a, In order to make the contraction degree B of the negative electrode plate 8 due to the contraction of 6b and the contraction degree D of the positive electrode plate 4 at this time close to each other, the expansion and contraction is suppressed to the larger one during the charge / discharge of the positive electrode plate 4 and the negative electrode plate 8 The expansion / contraction suppression function is provided.

  In order to form the positive electrode mixture layers 2a and 2b on the front surface or the back surface of the positive electrode current collector 1 as described above, a positive electrode active material, a conductive material, and a binder are placed in an appropriate dispersion medium, and a planetary mixer, etc. And then kneading while adjusting the viscosity to be optimal for application to the positive electrode current collector 1 such as an aluminum foil to prepare a positive electrode mixture paint. Here, as the positive electrode active material, for example, lithium cobaltate and modified products thereof (such as lithium cobaltate in which aluminum or magnesium is dissolved), lithium nickelate and modified products thereof (partially nickel is substituted with cobalt) Composite oxides such as lithium manganate and modified products thereof.

  As the conductive material at this time, for example, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black, and various graphites may be used alone or in combination. As the binder at this time, for example, polyvinylidene fluoride (PVdF), a modified polyvinylidene fluoride, polytetrafluoroethylene (PTFE), a rubber particle binder having an acrylate unit, and the like can be used. It is also possible to mix an acrylate monomer or an acrylate oligomer having a reactive functional group introduced into the binder. The positive electrode mixture paint prepared as described above is applied on the positive electrode current collector 1 made of, for example, an aluminum foil using a die coater, dried and pressed to a predetermined thickness. By slitting into a width and a length, a long belt-like positive electrode plate 4 is obtained.

On the other hand, in order to form the negative electrode mixture layers 6a and 6b on the front or back surface of the negative electrode current collector 5, the negative electrode active material and the binder are placed in an appropriate dispersion medium and mixed by a disperser such as a planetary mixer. Disperse and knead while adjusting the viscosity to be optimal for application to the negative electrode current collector 5 such as a copper foil to prepare a negative electrode mixture paint. Here, as the negative electrode active material, for example, various natural graphites and artificial graphites, silicon-based composite materials such as silicide, and various alloy composition materials can be used. As the binder at this time, polyvinylidene fluoride and a modified product thereof can be used. However, from the viewpoint of improving the acceptability of lithium ions, a combination of a styrene-butadiene copolymer rubber particle (SBR) or a modified product thereof and a cellulose-based resin such as carboxymethyl cellulose (CMC), It is preferable to use a styrene-butadiene copolymer rubber particle or a modified product obtained by adding a small amount of the above cellulose resin.

  After applying the negative electrode mixture paint prepared as described above onto a negative electrode current collector 5 made of, for example, copper foil using a die coater, drying and pressing to compress to a predetermined thickness, Slitting process into the width and length gives the long strip-like negative electrode plate 8. Hereinafter, the nonaqueous secondary battery of the present invention using the positive electrode plate 4 and the negative electrode plate 8 described above will be described. FIG. 12 is a perspective view of a cylindrical lithium ion secondary battery 17 as an example of a non-aqueous secondary battery cut vertically. In the cylindrical lithium ion secondary battery 17 of FIG. 12, a positive electrode plate 4 using a composite lithium oxide as an active material and a negative electrode plate 8 using a material capable of holding lithium as an active material are spirally formed via a separator 9. As a result, the electrode group 10 is produced.

  The electrode group 10 is housed inside the bottomed cylindrical battery case 11 while being insulated from the battery case 11 by the insulating plate 12, while the negative electrode lead 13 led out from the lower part of the electrode group 10 is the battery case 11. The positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15. Further, the battery case 11 is filled with a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof after the non-aqueous electrolyte solution (not shown) made of a predetermined amount of a non-aqueous solvent is injected. The opening of the case 11 is crimped inward by bending inward. Here, the separator 9 may have any composition that can withstand the usage range of the lithium ion secondary battery, but it is particularly preferable to use a single or composite of microporous films of olefin resins such as polyethylene and polypropylene. . The thickness of the separator 9 is preferably 10 to 25 μm.

The non-aqueous electrolyte at this time can use various lithium compounds such as LiPF ₆ and LiBF ₄ as electrolyte salts. Further, ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (MEC) can be used alone or in combination as a solvent. Further, in order to form a good film on the positive electrode plate 4 or the negative electrode plate 8 and to ensure the stability at the time of overcharge, vinylene carbonate (VC) and cyclohexylbenzene (CHB), and modified products thereof are used. It is preferable to use it.

  As a first configuration of the expansion and contraction suppressing function that is a feature of the present invention, the electrode plate for a non-aqueous secondary battery according to the present invention is either one of the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. Can be realized by using an alloy having a small stretch. As an example of a specific configuration, the negative electrode current collector 5 shown in FIG. 2 is made of a copper alloy to make the negative electrode plate 8 difficult to stretch, and the degree of expansion A and B of the negative electrode plate 8 shown in FIG. The expansion and contraction degrees C and D of the plate 4 can be approached. Further, as a second configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention is tempered with either the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. This can be realized by curing.

  As an example of a specific configuration, the negative electrode current collector 5 shown in FIG. 2 is hardened by work hardening by heat treatment or the like to make the negative electrode plate 8 difficult to stretch, and the degree of expansion and contraction A, B of the negative electrode plate 8 shown in FIG. Can be brought close to the degree of expansion C and D of the positive electrode plate 4. As a third configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery according to the present invention has a thicker one of the positive electrode current collector 1 and the negative electrode current collector 5 as shown in FIG. This can be realized by configuring as above.

  As an example of a specific configuration, the negative electrode current collector 5 shown in FIG. 3 is made thicker by increasing the thickness T1 of the negative electrode current collector 5, so that the negative electrode plate 8 hardly stretches. 4 expansion / contraction degrees C and D can be approached. Further, as a fourth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention is orthogonal to the longitudinal direction of the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. This can be realized by providing the thick portion 5a.

  As an example of a specific configuration, the negative electrode current collector 5 shown in FIG. 4 is provided with a thick portion 5a orthogonal to the longitudinal direction, thereby making the negative electrode plate 8 difficult to extend. The expansion degrees A and B can be made close to the expansion degrees C and D of the positive electrode plate 4. Further, as a fifth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention is configured by widening the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. This can be achieved.

  As an example of a specific configuration, by making the width W1 of the negative electrode current collector 5 shown in FIG. 5 wide, it is difficult for the negative electrode plate 8 to stretch. C, D can be approached. Further, as a sixth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery according to the present invention includes the positive electrode current collector 1 or the negative electrode current collector 5 made of an alloy having a small expansion / contraction degree as shown in FIG. 2 or cured by a tempering treatment as shown in FIG. 2, or thickened as shown in FIG. 3, or provided with a thick portion 5a orthogonal to the longitudinal direction as shown in FIG. As shown in FIG. 5, it is possible to make the degree of expansion / contraction of the positive electrode plate 4 and the degree of expansion / contraction of the negative electrode plate 8 close to each other by combining any two or more of the widths. Further, as a seventh configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention has a thick positive electrode mixture layer 2a, 2b or negative electrode mixture layer 6a, 6b as shown in FIG. This can be achieved.

  As an example of a specific configuration, by increasing the thickness T2 of the negative electrode mixture layers 6a and 6b shown in FIG. The degree of expansion and contraction can be close to C and D. Further, as an eighth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery according to the present invention reduces the active material density of the positive electrode mixture layers 2a and 2b as shown in FIG. This can be realized by increasing the active material density of 6a and 6b.

  As an example of a specific configuration, by reducing the active material density of the positive electrode mixture layers 2a and 2b shown in FIG. 2, the negative electrode plate 8 expands when lithium is occluded and the negative electrode plate releases lithium. 8 can be relaxed, and the degree of expansion C and D of the positive electrode plate 4 can be made closer to the degree of expansion A and B of the negative electrode plate 8. As a ninth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery according to the present invention has the porosity of the positive electrode mixture layers 2a and 2b or the negative electrode mixture layers 6a and 6b as shown in FIG. This can be achieved by increasing the size.

  As an example of a specific configuration, by increasing the porosity of the negative electrode mixture layers 6 a and 6 b shown in FIG. 2, the negative electrode plate 8 is hardly stretched, and the expansion and contraction degrees A and B of the negative electrode plate 8 are set to the positive electrode plate 4. The degree of expansion and contraction C, D can be approached. Further, as a tenth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention is formed by forming the positive electrode mixture layers 2a and 2b or the negative electrode mixture layers 6a and 6b as shown in FIG. This can be achieved by increasing the hardness of the dressing.

As an example of a specific configuration, by increasing the hardness of the binder forming the negative electrode mixture layers 6a and 6b shown in FIG. B can be brought close to the degree of expansion C and D of the positive electrode plate 4. Further, as an eleventh configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery of the present invention has a thick positive electrode mixture layer 2a, 2b or negative electrode mixture layer 6a, 6b as shown in FIG. Either to reduce the active material density as shown in FIG. 2, increase the porosity as shown in FIG. 2, or increase the hardness of the binder as shown in FIG. By combining the above, it is also possible to make the expansion and contraction degrees C and D of the positive electrode plate 4 and the expansion and contraction degrees A and B of the negative electrode plate 8 close to each other. As a twelfth configuration of the expansion / contraction suppression function, the electrode plate for a non-aqueous secondary battery according to the present invention is provided with the expansion / contraction suppression function in the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. This can be realized by providing the positive electrode mixture layers 2a and 2b or the negative electrode mixture layers 6a and 6b.

  As an example of a specific configuration, as shown in FIG. 7, the negative electrode current collector 5 is provided with a thick portion 5a orthogonal to the longitudinal direction, and the negative electrode mixture layers 6a and 6b are made thicker T2. Yes. Moreover, as a structure which added the expansion / contraction relaxation function to the expansion / contraction suppression function, the electrode plate for non-aqueous secondary batteries of the present invention has an expansion / contraction suppression function in the positive electrode current collector 1 or the negative electrode current collector 5 as shown in FIG. And providing exposed portions 3a and 3b orthogonal to the longitudinal direction of the positive electrode current collector 1 or the negative electrode current collector 5 in the positive electrode mixture layers 2a and 2b or the negative electrode mixture layers 6a and 6b. Can be realized.

  As an example of a specific configuration, the thickness T1 of the negative electrode current collector 5 is increased as shown in FIG. 8, and the exposed portions 3a and 3b orthogonal to the longitudinal direction of the positive electrode mixture layers 2a and 2b are the same. It forms so that it may become a phase. As another configuration in which expansion / contraction relaxation function is added to expansion / contraction suppression function, the nonaqueous secondary battery electrode plate of the present invention has positive electrode mixture layers 2a and 2b or negative electrode mixture layers 6a and 6b as shown in FIG. This can be realized by providing an expansion / contraction suppressing function and providing an exposed portion in the positive electrode mixture layers 2a and 2b or the negative electrode mixture layers 6a and 6b.

  As an example of a specific configuration, as shown in FIG. 9, the negative electrode mixture layers 6a and 6b are made thicker and the exposed portions 3a and 3b are orthogonal to the longitudinal direction of the positive electrode mixture layers 2a and 2b. Are formed in the same phase. Moreover, as a structure combining the expansion / contraction suppression function and the expansion / contraction promotion function, the electrode plate for a non-aqueous secondary battery according to the present invention is provided with an expansion / contraction suppression function in the positive electrode plate 4 or the negative electrode plate 8 as shown in FIG. This can be realized by providing an expansion / contraction promotion function for promoting expansion / contraction in the direction in which the expansion / contraction during charging / discharging of the plate 4 and the negative electrode plate 8 is small.

  As an example of a specific configuration, as shown in FIG. 10, the negative electrode current collector 5 is provided with a thick portion 5a orthogonal to the longitudinal direction, and the positive electrode current collector 1 is thinned perpendicular to the longitudinal direction. Part 1a is provided. Hereinafter, specific examples will be described in more detail.

  As an example of the present invention, Example 1 in which a negative electrode current collector is made of an alloy that is difficult to stretch will be described with reference to the drawings. First, 100 parts by weight of lithium cobaltate as an active material, 2 parts by weight of acetylene black as a conductive material with respect to 100 parts by weight of the active material, and 2 parts by weight of polyvinylidene fluoride as a binder with respect to 100 parts by weight of the active material Was mixed with an appropriate amount of N-methyl-2-pyrrolidone in a double-arm kneader to prepare a positive electrode mixture paint. Next, as shown in FIG. 2, this positive electrode mixture paint was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried and then pressed. The thickness of the positive electrode mixture layers 2a and 2b was 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery.

  On the other hand, 100 parts by weight of artificial graphite as the active material of the negative electrode, and 2.5 parts by weight of styrene-butadiene copolymer rubber particle dispersion (solid content 40% by weight) as the binder with respect to 100 parts by weight of the active material ( 1 part by weight in terms of solid content of the binder), 1 part by weight of carboxymethyl cellulose as a thickener with respect to 100 parts by weight of the active material, and an appropriate amount of water, and agitation in a double-arm kneader. An agent paint was prepared. Next, as shown in FIG. 2, this negative electrode mixture paint is applied to a negative electrode current collector 5 made of Cu alloy foil to which Pb, Fe, Zn, Ni, and Mn having a thickness of 10 μm are added, dried, and pressed. The thickness of the negative electrode mixture layers 6a and 6b on one side was set to 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 1.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode current collector 5 is made of a Cu alloy to which Pb, Fe, Zn, Ni, and Mn are added, so that the negative electrode plate 8 is hardly stretched, and the degree of expansion and contraction A and B of the negative electrode plate 8 is adjusted. Thus, it is considered that good battery performance was maintained.

  As an example of the present invention, a second example in which a negative electrode current collector is cured by a tempering process will be described with reference to the drawings. First, as shown in FIG. 2, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 2, a negative electrode current collector made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm, which was previously cured by work hardening by heat treatment of the same negative electrode mixture paint as in Example 1 It was applied to the body 5 and dried, and then pressed to make the thickness of the negative electrode mixture layers 6a and 6b on one side of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 2.

Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode current collector 5 is hardened by work hardening, so that the negative electrode plate 8 is difficult to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be brought close to the expansion and contraction degrees C and D of the positive electrode plate 4. It is considered that good battery performance could be maintained.

  As an example of the present invention, Example 3 configured by increasing the thickness of the negative electrode current collector will be described with reference to the drawings. First, as shown in FIG. 3, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 3, a negative electrode current collector made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 12 μm made of the same negative electrode mixture paint as that of Example 1, which is thicker than the standard thickness of 10 μm. It was applied to the body 5 and dried, and then pressed to make the thickness of the negative electrode mixture layers 6a and 6b on one side of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 3.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the thickness of the negative electrode current collector 5 is increased so that the negative electrode plate 8 is difficult to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be brought close to the expansion and contraction degrees C and D of the positive electrode plate 4, respectively. It is thought that the battery performance was maintained.

  As an example of the present invention, Example 4 configured by providing a negative electrode current collector with a thick portion orthogonal to the longitudinal direction will be described with reference to the drawings. First, as shown in FIG. 4, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 4, a tough pitch copper foil having a thickness of 10 μm, in which a negative electrode mixture paint similar to that of Example 1 is provided with thick portions 5a having a height of 2 μm at equal intervals in the direction perpendicular to the longitudinal direction ( The negative electrode current collector 5 made of Cu (purity: 99.9%) was applied and dried, and then pressed to make the thickness of the negative electrode mixture layers 6a and 6b on one side of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 4.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode current collector 5 is provided with the thick portion 5a to make the negative electrode plate 8 difficult to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be brought close to the expansion and contraction degrees C and D of the positive electrode plate 4, respectively. Thus, it is considered that good battery performance could be maintained. In Example 4, as the thick part 5a orthogonal to the longitudinal direction of the negative electrode current collector 5, the semicircular thick part 5a was provided as shown in FIG. 4, but the present invention is not limited to this. Needless to say, the thick portion 5a may have a certain width.

  As an embodiment of the present invention, a fifth embodiment in which the width of the negative electrode current collector is widened will be described with reference to the drawings. First, as shown in FIG. 5, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a standard width of 56 mm. On the other hand, as shown in FIG. 5, the same negative electrode mixture paint as in Example 1 was applied to a negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm and dried. The thickness of the negative electrode mixture layers 6a and 6b on one side was set to 85 μm. Then, the negative electrode plate 8 was produced by slitting so that the width W1 wider than the reference width of 58 mm was 59 mm.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 5.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the width of the negative electrode current collector 5 is widened so that the negative electrode plate 8 is difficult to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be brought close to the expansion and contraction degrees C and D of the positive electrode plate 4. It is thought that the battery performance was maintained.

  As one example of the combination of Examples 1 to 5 in the present invention, the negative electrode current collector is composed of an alloy having a small expansion and contraction, and the negative electrode current collector is provided with a thick portion perpendicular to the longitudinal direction. Example 6 will be described with reference to the drawings. First, as shown in FIG. 4, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 4, a negative electrode mixture paint similar to that in Example 1 is provided with Pb, Fe, and 10 μm thick Pb, Fe, The negative electrode current collector 5 made of Cu alloy foil added with Zn, Ni, Mn was applied to the negative electrode current collector 5 and dried, followed by pressing to make the thickness of the negative electrode mixture layers 6a and 6b on one side to 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was designated as Example 6.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because, in addition to the effect that the negative electrode current collector 5 is made of an alloy having a small degree of expansion and contraction, the negative electrode plate 8 is further hardly stretched due to the synergistic effect of the thick portion 5a provided on the negative electrode current collector 5, It is considered that the degree of expansion and contraction A and B of 8 can be brought close to the degree of expansion and contraction C and D of the positive electrode plate 4, and good battery performance can be maintained.

  As an example of the present invention, Example 7 in which the thickness of the negative electrode mixture layer is increased will be described with reference to the drawings. First, as shown in FIG. 6, the same positive electrode mixture paint as in Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm and dried. The active material density was 3.6 g / cc and the thickness of the positive electrode mixture layers 2a and 2b on one side was 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 6, the same negative electrode mixture paint as in Example 1 was applied to a negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm and dried. Later, the thickness T2 of the negative electrode mixture layers 6a and 6b on one side was set to 90 μm, which was thicker than the standard thickness of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 7.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because by increasing the thickness of the negative electrode mixture layers 6a and 6b, it is difficult for the negative electrode plate 8 to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be made closer to the expansion and contraction degrees C and D of the positive electrode plate 4, respectively. It is considered that good battery performance could be maintained.

  As an example of the present invention, Example 8 in which the active material density of the positive electrode mixture layer is reduced will be described with reference to the drawings. First, as shown in FIG. 2, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm and dried. The active material density was 3.4 g / cc, which was pressed to be smaller than the standard active material density of 3.6 g / cc, and the thickness of the positive electrode mixture layers 2a, 2b on one side was 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. Next, as shown in FIG. 2, the same negative electrode mixture paint as in Example 1 was applied to the negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm and dried. Later, the active material density was set to 1.6 g / cc, and the thickness of the negative electrode mixture layers 6a and 6b on one side was set to 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was designated as Example 8. Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed.

This is because by reducing the active material density of the positive electrode mixture layers 2a and 2b, the amount of intercalated lithium is relatively reduced, and the expansion and contraction of the negative electrode mixture layers 6a and 6b is alleviated. It is considered that the plate 8 is made difficult to stretch, and the expansion and contraction degrees C and D of the positive electrode plate 4 can be brought close to the expansion and contraction levels A and B of the negative electrode plate 8, respectively. In Example 8, the active material density of the positive electrode mixture layers 2a and 2b was reduced. However, the present invention is not limited to this. By increasing the active material density of the negative electrode mixture layers 6a and 6b, By relatively increasing the amount of lithium that can be categorized and suppressing the expansion and contraction of the negative electrode mixture layers 6 a and 6 b, the negative electrode plate 8 is hardly stretched. It is also possible to approach the degree of elasticity C and D in the same way.

  As an example of the present invention, Example 9 in which the porosity of the negative electrode mixture layer is increased will be described with reference to the drawings. First, as shown in FIG. 2, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm and dried. The thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. Next, as shown in FIG. 2, the same negative electrode mixture paint as in Example 1 was applied to the negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm and dried. Later, the active material density was 1.6 g / cc, and the thickness of the negative electrode mixture layers 6a and 6b on one side was 89 μm, and the porosity was 28%, which was larger than the reference porosity of 25%. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 9. Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode mixture layers 6 a and 6 b have increased porosity, which makes the negative electrode plate 8 difficult to stretch, and the expansion and contraction degrees A and B of the negative electrode plate 8 can be made closer to the expansion and contraction degrees C and D of the positive electrode plate 4. It is considered that good battery performance could be maintained.

  As an example of the present invention, Example 10 configured by increasing the hardness of the binder forming the negative electrode mixture layer will be described with reference to the drawings. First, as shown in FIG. 2, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm, dried, and then pressed. Thus, the thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, 100 parts by weight of artificial graphite as an active material for the negative electrode, 2.5 parts by weight of polyvinylidene fluoride as a binder for 100 parts by weight of the active material, and a suitable amount of N-methyl-2-pyrrolidone The mixture was stirred with a kneader to prepare a negative electrode mixture paint. Next, this negative electrode mixture coating material was applied to a negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm, dried and then pressed to form a negative electrode mixture layer on one side. The thickness of 6a, 6b was 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery.

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Subsequently, the positive electrode lead 14 led out from the upper part of the electrode group 10 was connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC were dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 10.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the hardness of the negative electrode plate 8 is increased by changing the binder used for the negative electrode plate 8 from the styrene-butadiene copolymer rubber particle dispersion to the polyvinylidene fluoride, thereby extending the negative electrode plate 8. It is considered that the degree of expansion and contraction A and B of the negative electrode plate 8 can be made closer to the degree of expansion and contraction C and D of the positive electrode plate 4 and good battery performance can be maintained.

  As an example of the combination of Examples 10 to 13 in the present invention, while referring to the drawing, Example 11 was configured with the negative electrode mixture layer thickened and the active material density of the positive electrode mixture layer reduced. explain. First, as shown in FIG. 2, a positive electrode mixture paint similar to that of Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm and dried. The active material density was 3.4 g / cc, which was pressed to be smaller than the standard active material density of 3.6 g / cc, and the thickness of the positive electrode mixture layers 2a, 2b on one side was 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. Next, as shown in FIG. 2, the same negative electrode mixture paint as in Example 1 was applied to a negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm and dried. After that, the thickness T2 of the negative electrode mixture layers 6a and 6b on one side was set to 90 μm, which was thicker than the standard thickness of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 was connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC were dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 11.

Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the thickness of the negative electrode mixture layers 6a and 6b is increased.
The negative electrode plate 8 is made difficult to extend and the active material density of the positive electrode mixture layers 2a and 2b is lowered, so that the amount of lithium intercalated is relatively reduced, and the negative electrode mixture layers 6a and 6b expand and contract. It is considered that the negative electrode plate 8 is made difficult to extend by relaxing the above, and the expansion and contraction degrees C and D of the positive electrode plate 4 can be brought close to the expansion and contraction degrees A and B of the negative electrode plate 8, respectively. .
In Example 11, the active material density of the positive electrode mixture layers 2a and 2b is reduced. However, the present invention is not limited to this, and the active material density of the negative electrode mixture layers 6a and 6b is increased. It is also possible to make the negative electrode plate 8 difficult to stretch by relatively increasing the amount of lithium that can be intercalated in the same manner, and to make the degree of expansion A and B of the negative electrode plate 8 close to the degree of expansion C and D of the positive electrode plate 4. is there.

  As an example of the present invention, Example 12 in which a negative electrode current collector is provided with a thick portion perpendicular to the longitudinal direction and the thickness of the negative electrode mixture layer is increased will be described with reference to the drawings. First, as shown in FIG. 7, the same positive electrode mixture paint as in Example 1 was applied to a positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm and dried. The active material density was 3.6 g / cc and the thickness of the positive electrode mixture layers 2a and 2b on one side was 75 μm. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery. On the other hand, as shown in FIG. 7, a tough pitch copper foil having a thickness of 10 μm, in which a negative electrode mixture paint similar to that of Example 1 is provided with thick portions 5 a having a height of 2 μm at equal intervals in the direction perpendicular to the longitudinal direction. It was applied to the negative electrode current collector 5 made of (Cu purity: 99.9%), dried and pressed to make the thickness T2 of the negative electrode mixture layers 6a and 6b on one side thicker than the standard thickness of 85 μm. The thickness was 90 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced.

More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 12.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because, in addition to the effect of the thick portion 5a provided in the negative electrode current collector 5, the negative electrode plate 8 is made more difficult to extend due to the synergistic effect of increasing the thickness of the negative electrode mixture layers 6a and 6b. It is considered that the degrees A and B can be made close to the degree of expansion and contraction C and D of the positive electrode plate 4, and good battery performance can be maintained.

As one example of the present invention, the negative electrode current collector was thickened, and exposed portions perpendicular to the longitudinal direction of the positive electrode current collector were provided in the same phase on the front and back surfaces of the positive electrode mixture layer. Example 13 will be described with reference to the drawings. First, as shown in FIG. 8, the same positive electrode mixture paint as that of Example 1 was applied to the longitudinal direction of the positive electrode current collector 1 made of an aluminum foil having a thickness of 15 μm (Al purity: 99.85%). An exposed portion 3a having a width of 5 mm is formed on the surface in the vertical direction at an equal pitch, and an exposed portion 3b having the same phase as the surface is formed on the back surface in the direction perpendicular to the longitudinal direction of the positive electrode current collector 1 at an equal pitch. A positive electrode plate 4 was produced in which the thickness of the positive electrode mixture layers 2a, 2b on one side was 100 μm after being provided uniformly in the longitudinal direction, intermittently applied, and dried. Next, this positive electrode plate 4 is pressed so that the total thickness becomes 165 μm, so that the thickness of the positive electrode mixture layers 2 a and 2 b on one side is 75 μm, and the exposed portion 3 a having a width of 5 mm is formed on the surface. An exposed portion 3b having the same phase as the front surface and a width of 5 mm was formed uniformly on the back surface in the longitudinal direction. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery.

  On the other hand, as shown in FIG. 8, a negative electrode assembly made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 12 μm, which is a thicker than the standard thickness of 10 μm of the same negative electrode mixture paint as in Example 1. It applied to the electric body 5, dried, and pressed, and the thickness of the negative electrode mixture layers 6a and 6b on one side was set to 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11.

Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 13.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode current collector 5 is made thick so that the negative electrode plate 8 is hardly stretched and the exposed portions 3a and 3b are provided uniformly in the longitudinal direction of the positive electrode current collector 1. The exposed portions 3a and 3b exhibit the effect of relaxing the stress associated with expansion and contraction to relieve the stress applied to the positive electrode plate 4, and bring the expansion and contraction degrees C and D of the positive electrode plate 4 closer to the expansion and contraction levels A and B of the negative electrode plate 8, respectively. It is considered that good battery performance was maintained.

  As an embodiment of the present invention, the thickness of the negative electrode mixture layer was increased, and the exposed portion perpendicular to the longitudinal direction of the positive electrode current collector was provided in the same phase on the front and back surfaces of the positive electrode mixture layer. Example 14 will be described with reference to the drawings. First, as shown in FIG. 9, the same positive electrode mixture paint as in Example 1 was applied to the longitudinal direction of the positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm. An exposed portion 3a having a width of 5 mm is formed on the surface in the vertical direction at an equal pitch, and an exposed portion 3b having the same phase as the surface is formed on the back surface in the direction perpendicular to the longitudinal direction of the positive electrode current collector 1 at an equal pitch. A positive electrode plate 4 was produced in which the thickness of the positive electrode mixture layers 2a, 2b on one side was 100 μm after being provided uniformly in the longitudinal direction, intermittently applied, and dried. Next, this positive electrode plate 4 is pressed so that the total thickness becomes 165 μm, so that the thickness of the positive electrode mixture layers 2 a and 2 b on one side is 75 μm, and the exposed portion 3 a having a width of 5 mm is formed on the surface. An exposed portion 3b having the same phase as the front surface and a width of 5 mm was formed uniformly on the back surface in the longitudinal direction. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery.

  On the other hand, as shown in FIG. 9, the same negative electrode mixture paint as in Example 1 was applied to a negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 12 μm and dried. Later, the thickness T2 of the negative electrode mixture layers 6a and 6b on one side was set to 90 μm, which was thicker than the standard thickness of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11.

Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 14.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This is because the negative electrode mixture layers 6a and 6b are made thick so that the negative electrode plate 8 is difficult to extend and the exposed portions 3a and 3b are provided uniformly in the longitudinal direction of the positive electrode current collector 1. Thus, the exposed portions 3a and 3b exhibit the effect of relaxing the stress associated with expansion and contraction to relieve the stress applied to the positive electrode plate 4, and the expansion and contraction degrees C and D of the positive electrode plate 4 are set to the expansion and contraction levels A and D of the negative electrode plate 8, respectively. It is considered that good battery performance could be maintained because it was able to approach B.

  As an example of the present invention, about Example 15 in which the positive electrode current collector is provided with a thin part perpendicular to the longitudinal direction and the negative electrode current collector is provided with a thick part perpendicular to the longitudinal direction This will be described with reference to the drawings. First, as shown in FIG. 10, a positive electrode mixture paint similar to that of Example 1 was provided with thin portions 1a having a depth of 2 μm at equal intervals in the direction perpendicular to the longitudinal direction, and an aluminum foil having a thickness of 15 μm (Al The thickness of the positive electrode mixture layers 2a and 2b on one side was set to 75 μm after being applied to a positive electrode current collector 1 having a purity of 99.85% and dried. Then, the positive electrode plate 4 was produced by slitting to a specified width of the cylindrical battery.

  On the other hand, as shown in FIG. 10, a tough pitch copper foil having a thickness of 10 μm, in which a negative electrode mixture paint similar to that of Example 1 is provided with thick portions 5a having a height of 2 μm at equal intervals in the direction perpendicular to the longitudinal direction ( The negative electrode current collector 5 made of Cu (purity: 99.9%) was applied and dried, and then pressed to make the thickness of the negative electrode mixture layers 6a and 6b on one side of 85 μm. Then, the negative electrode plate 8 was produced by slitting to a specified width of the cylindrical battery. Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 of a polyethylene microporous film having a thickness of 20 μm were produced. The electrode group 10 was housed in the bottomed cylindrical battery case 11 together with the insulating plate 12, and the negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11.

Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was taken as Example 15.

  Charging / discharging of 100 lithium ion secondary batteries 17 produced as described above was repeated 500 cycles, but cycle deterioration did not occur. Moreover, when 20 pieces were extracted from 100 pieces of 100 lithium ion secondary batteries 17 after repeating 500 cycles of charge and discharge, and the electrode group 10 was disassembled, lithium deposition, electrode plate breakage, electrode plate buckling, electrode No defects such as dropping of the mixture layer were observed. This made the positive electrode plate 4 easy to extend by providing the thin part 1 a on the positive electrode current collector 1, and made the negative electrode plate 8 difficult to extend by providing the thick part 5 a on the negative electrode current collector 5. Thus, it is considered that the degree of expansion and contraction C and D of the positive electrode plate 4 and the degree of expansion and contraction A and B of the negative electrode plate 8 can be brought close to each other, and good battery performance can be maintained.

(Comparative Example 1)
First, as shown in FIG. 11, the same positive electrode mixture paint as that of Example 1 was applied to the positive electrode current collector 1 made of an aluminum foil (Al purity: 99.85%) having a thickness of 15 μm (reference thickness). After drying and pressing, the active material density is 3.6 g / cc (standard active material density), the thickness of the positive electrode mixture layers 2a and 2b on one side is 75 μm (standard thickness), and the porosity is 15%. (Standard porosity). Then, the positive electrode plate 4 was produced by slitting to a width of 56 mm (reference width). On the other hand, as shown in FIG. 11, the same negative electrode mixture paint as in Example 1 was applied to the negative electrode current collector 5 made of a tough pitch copper foil (Cu purity: 99.9%) having a thickness of 10 μm (reference thickness). After coating, drying and pressing, the active material density is 1.6 g / cc (reference active material density), the thickness of the negative electrode mixture layers 6a and 6b on one side is 85 μm (reference thickness), and the porosity is 25. % (Standard porosity). Then, the negative electrode plate 8 was produced by slitting to a width of 58 mm (reference width).

Using the positive electrode plate 4 and the negative electrode plate 8 produced as described above, a cylindrical lithium ion secondary battery 17 as shown in FIG. 12 was produced. More specifically, 100 electrode groups 10 in which the positive electrode plate 4 and the negative electrode plate 8 were spirally wound through a separator 9 made of a polyethylene microporous film having a thickness of 20 μm were produced. Ten electrodes were extracted from the electrode group 10 and accommodated in the bottomed cylindrical battery case 11 together with the insulating plate 12. A negative electrode lead 13 led out from the lower part of the electrode group 10 was connected to the bottom of the battery case 11. Next, the positive electrode lead 14 led out from the upper part of the electrode group 10 is connected to the sealing plate 15, and 1 part of LiPF ₆ and 3 parts by weight of VC are dissolved in a predetermined amount of EC, DMC, and MEC mixed solvent in the battery case 11. A non-aqueous electrolyte solution (not shown) was injected. Thereafter, a sealing plate 15 having a sealing gasket 16 attached to the periphery thereof is inserted into the opening of the battery case 11, the opening of the battery case 11 is bent inward, and caulked and sealed. The secondary battery 17 was set as Comparative Example 1.

  As a result of repeating the charge / discharge of 100 lithium ion secondary batteries 17 produced as described above for 500 cycles, cycle deterioration was observed in 4 out of 100 batteries. Thus, when the four lithium ion secondary batteries 17 were disassembled, one was broken by the positive electrode plate 4 and three were bent by the negative electrode plate 8. In the lithium ion secondary battery 17 of Comparative Example 1 described above, the degree of expansion C of the positive electrode plate 4 with respect to the degree of expansion A and B of the negative electrode plate 8 due to expansion and contraction of the negative electrode mixture layers 6a and 6b during charging and discharging. Since D could not follow, it is considered that the positive electrode plate 4 was broken and the negative electrode plate 8 was buckled.

The non-aqueous secondary battery according to the present invention includes a positive and negative electrode plate at the time of charge and discharge, by providing a stretch suppressing function that suppresses expansion and contraction on the larger degree of expansion and contraction at the time of charge and discharge of the positive electrode plate and the negative electrode plate. The stress applied to the positive electrode plate or negative electrode plate due to the difference in degree of expansion and contraction due to the expansion and contraction of the negative electrode plate can be relaxed, and it is possible to suppress breakage or buckling of the electrode plate, and internal short circuit caused by these Therefore, it is possible to provide a highly safe non-aqueous secondary battery, so that it is useful as a portable power source or the like for which higher capacity is desired along with the multifunctionalization of electronic devices and communication devices.

DESCRIPTION OF SYMBOLS 1 Positive electrode collector 1a Thin part 2a, 2b Positive electrode mixture layer 3a, 3b Exposed part 4 Positive electrode plate 5 Negative electrode collector 5a Thick part 6a, 6b Negative electrode mixture layer 8 Negative electrode plate 9 Separator 10 Electrode group 11 Battery case 12 Insulating plate 13 Negative electrode lead 14 Positive electrode lead 15 Sealing plate 16 Sealing gasket 17 Lithium ion secondary battery A, B Elasticity of negative electrode plate C, D Elasticity of positive electrode plate T1 Negative electrode current collector thickness T2 Negative electrode mixture layer Thickness W1 Width of negative electrode current collector

Claims (18)

  A positive electrode plate having a positive electrode mixture layer formed by applying a positive electrode mixture paint obtained by kneading and dispersing an active material comprising at least a lithium-containing composite oxide, a conductive material, and a binder in a dispersion medium on a positive electrode current collector; A negative electrode mixture coating material in which an active material made of a material capable of holding lithium and a binder are kneaded and dispersed in a dispersion medium is applied on the negative electrode current collector to form a porous material between the negative electrode plate and the negative electrode plate. A non-aqueous secondary battery in which an electrode group formed by winding or stacking in a spiral shape with a porous insulator interposed therein is enclosed in a battery case together with a non-aqueous electrolyte solution, during charging and discharging of the positive electrode plate and the negative electrode plate A non-aqueous secondary battery having a configuration in which an expansion / contraction suppression function for suppressing expansion / contraction is provided on the side having a larger expansion / contraction degree.   The non-aqueous secondary battery according to claim 1, wherein the expansion / contraction suppression function is provided in a positive electrode current collector or a negative electrode current collector.   The non-aqueous secondary battery according to claim 2, wherein a positive electrode current collector or a negative electrode current collector is configured by using an alloy having a low expansion / contraction degree as the expansion / contraction suppression function.   The non-aqueous secondary battery according to claim 2, wherein the non-aqueous secondary battery is configured by curing a positive electrode current collector or a negative electrode current collector by a tempering treatment as the expansion / contraction suppression function.   The non-aqueous secondary battery according to claim 2, wherein a thickness of the positive electrode current collector or the negative electrode current collector is increased as the expansion / contraction suppression function.   The non-aqueous secondary battery according to claim 2, wherein as the expansion / contraction suppression function, the positive electrode current collector or the negative electrode current collector is provided with a thick portion orthogonal to the longitudinal direction.   The non-aqueous secondary battery according to claim 2, wherein a width of the positive electrode current collector or the negative electrode current collector is widened as the expansion / contraction suppression function.   As the expansion / contraction suppression function, a positive electrode current collector or a negative electrode current collector is composed of an alloy having a low expansion / contraction degree, or is hardened by a tempering treatment, or thickened, or a thick portion perpendicular to the longitudinal direction. The nonaqueous secondary battery according to claim 2, wherein the nonaqueous secondary battery is configured by combining any two or more of providing or widening the width.   The non-aqueous secondary battery according to claim 1, wherein the expansion / contraction suppression function is provided in a positive electrode mixture layer or a negative electrode mixture layer.   The non-aqueous secondary battery according to claim 9, wherein, as the expansion / contraction suppression function, the positive electrode mixture layer or the negative electrode mixture layer of the electrode plate having a large expansion / contraction degree is thickened.   The non-aqueous secondary battery according to claim 9, wherein, as the expansion / contraction suppression function, the active material density of the positive electrode mixture layer is reduced or the active material density of the negative electrode mixture layer is increased.   The non-aqueous secondary battery according to claim 9, wherein, as the expansion / contraction suppression function, the positive electrode mixture layer or the negative electrode mixture layer of the electrode plate having a large expansion / contraction degree is configured to have a large porosity.   10. The non-aqueous secondary battery according to claim 9, wherein the non-aqueous secondary battery is configured by increasing a hardness of a binder forming the positive electrode mixture layer or the negative electrode mixture layer as the expansion / contraction suppression function. As the expansion / contraction suppression function, the thickness of the positive electrode mixture layer or the negative electrode mixture layer is increased, or the active material density of the positive electrode mixture layer is decreased or the active material density of the negative electrode mixture layer is increased, or the porosity is increased. The non-aqueous secondary battery according to claim 9, which is a combination of any two or more of increasing the hardness of the binder or increasing the hardness of the binder.   2. The non-aqueous secondary battery according to claim 1, wherein the expansion / contraction suppression function is provided in a positive electrode current collector or a negative electrode current collector and is provided in the positive electrode mixture layer or the negative electrode mixture layer.   The expansion / contraction suppressing function is provided in the positive electrode current collector or the negative electrode current collector, and at least one surface of the positive electrode mixture layer or the negative electrode mixture layer is exposed to be orthogonal to the longitudinal direction of the positive electrode current collector or the negative electrode current collector The non-aqueous secondary battery according to claim 1, wherein the non-aqueous secondary battery is provided with an expansion / contraction relaxation function.   The expansion / contraction suppressing function is provided in the positive electrode mixture layer or the negative electrode mixture layer, and at least one surface of the positive electrode mixture layer or the negative electrode mixture layer is exposed to be orthogonal to the longitudinal direction of the positive electrode current collector or the negative electrode current collector The non-aqueous secondary battery according to claim 1, wherein the non-aqueous secondary battery is provided with an expansion / contraction relaxation function.   A positive electrode plate having a positive electrode mixture layer formed by applying a positive electrode mixture paint obtained by kneading and dispersing an active material comprising at least a lithium-containing composite oxide, a conductive material, and a binder in a dispersion medium on a positive electrode current collector; A negative electrode mixture coating material in which an active material made of a material capable of holding lithium and a binder are kneaded and dispersed in a dispersion medium is applied on the negative electrode current collector to form a porous material between the negative electrode plate and the negative electrode plate. A non-aqueous secondary battery in which an electrode group formed by winding or stacking in a spiral shape with a porous insulator interposed therein is enclosed in a battery case together with a non-aqueous electrolyte solution, during charging and discharging of the positive electrode plate and the negative electrode plate The expansion / contraction suppressing function for suppressing expansion / contraction is provided on the larger one of the expansion / contraction degree, and the expansion / contraction promotion function for promoting expansion / contraction is provided on the one having the smaller expansion / contraction degree during charging / discharging of the positive electrode plate and the negative electrode plate. Non-aqueous secondary battery.

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