JP2011023129A - Method of manufacturing positive electrode plate for nonaqueous secondary battery, and manufacturing device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem, wherein breaking or buckling of a positive electrode plate that causes internal short circuiting of a battery is generated due to the difference in the degree of expansion and contraction, between the positive electrode plate and a negative electrode plate, by repeated charge and discharge, due to the stress caused by expansion and contraction of the electrode plate applied to the electrode plate, when a nonaqueous secondary battery is repeatedly charged-discharged. <P>SOLUTION: A positive electrode plate 4 for a nonaqueous secondary battery having high reliability is manufactured by increasing the degree of expansion and contraction of the positive electrode plate 4 through a first step, in which positive mix coating is applied to a positive current collector, dried, and then they are pressed into a prescribed thickness; and then a second step in which the pressed current collector is heated to a temperature or higher, at which crystal grains of the positive current collector grow with heating rolls 1, 2, 3, releasing stress applied to the positive electrode plate 4 in which the degree of expansion and contraction is low, caused by the difference of the degree of expansion and contraction between the positive electrode plate 4 and the negative electrode plate in the expansion and contraction of the electrode plate in charging/discharging, and suppressing the generation of breaking or buckling of the positive electrode plate 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a positive electrode plate for a non-aqueous secondary battery represented by a lithium ion secondary battery and a manufacturing apparatus therefor.

  In recent years, lithium secondary batteries as non-aqueous secondary batteries, which are widely used as power sources for portable electronic devices, use a carbonaceous material capable of occluding and releasing lithium ions for the negative electrode, and LiCoO 2 for the positive electrode. By using a composite oxide of transition metal and lithium as an active material, a non-aqueous secondary battery having a high potential and a high discharge capacity has been realized, but expectations for further higher discharge capacity are increasing. In order to increase the discharge capacity, it is necessary to enclose more positive electrode active material, negative electrode carbon material, and non-aqueous electrolyte in the battery case. To that end, a space volume in the non-aqueous secondary battery is secured. There is a need. Examples of means for securing the volume include thinning the metal case, improving the active material density, and reducing the thickness of the current collector.

  Among them, regarding the thinning of the positive electrode current collector in the positive electrode plate for a non-aqueous secondary battery (hereinafter abbreviated as the positive electrode plate), contrary to the fact that the space volume can be easily secured, There are problems such as wrinkles, tears, charge / discharge characteristics of non-aqueous secondary batteries, especially the positive electrode current collector cannot withstand expansion and contraction during the charge / discharge cycle, the strength decreases, and the positive electrode mixture layer falls off is doing. From this, the positive electrode current collector of the positive electrode plate needs to be a positive electrode current collector corresponding to the productivity of the thin film, and can be a positive electrode current collector that can withstand expansion and contraction during the charge / discharge cycle. It becomes an important factor. In general, as a method for producing an electrode plate for a non-aqueous secondary battery, an electrode mixture paint obtained by kneading and dispersing a positive electrode active material or a negative electrode active material, a binder, and a conductive material in a dispersion medium is used on one side of the current collector. Or the method of forming a positive electrode plate or a negative electrode plate by apply | coating, drying, and pressing on both surfaces is used.

  Here, by using a copper foil having crystal grains grown by heat treatment as a current collector for the negative electrode plate, cracks on the copper foil are prevented and the negative electrode mixture paint is removed without deteriorating charge / discharge cycle characteristics. There has been proposed a method that does not generate (see, for example, Patent Document 1).

  In addition, in order to obtain a non-aqueous secondary battery excellent in charge / discharge cycle characteristics and storage characteristics, a current collector that is heat-treated at 250 ° C. or higher on the positive electrode plate and the negative electrode plate to increase flexibility and increase tensile elongation at break is used. A method has been proposed (see, for example, Patent Document 2).

  Further, the positive electrode plate after pressing is heat-treated at a temperature range of Tm-30 or higher (Tm is the melting point of polyvinylidene fluoride in the positive electrode mixture layer after pressing) Tm + 20 or lower, and the active portion of the positive electrode active material is polyvinylidene fluoride. There has been proposed a method for improving the discharge characteristics by suppressing the reaction in the highly active portion by covering the surface (for example, see Patent Document 3).

JP 2007-164996 A JP 09-129241 A JP 2007-273259 A

However, in the above-described prior art, when the non-aqueous secondary battery is charged / discharged, stress due to the expansion / contraction of the electrode plate is applied to the electrode plate, and the expansion / contraction degree of the positive electrode plate, the negative electrode plate or the separator due to repeated stress due to repeated charge / discharge. If the positive electrode plate or negative electrode plate breaks prior to the separator, the fracture portion of one of the electrode plates breaks through the separator and the positive electrode plate and the negative electrode plate are short-circuited. It will be. Due to this short circuit, a large current flows, and as a result, the temperature of the non-aqueous secondary battery suddenly rises and the non-aqueous secondary battery may have a problem of thermal runaway.

  In the prior art of Patent Document 1 described above, the content is limited to the copper foil of the negative electrode plate, and the positive electrode plate may not be able to improve the charge / discharge cycle without using a current collector with a similarly high degree of expansion / contraction. The expansion and contraction of the positive electrode plate is smaller than that of the negative electrode plate, and there is a problem that the positive electrode plate is broken or buckled. Further, in the prior art of Patent Document 2, even when a highly flexible current collector is used, the current collector undergoes work hardening during pressing, the degree of expansion and contraction is reduced, and charge / discharge cycle characteristics are deteriorated. Since the degree of expansion and contraction of the positive electrode plate is smaller than that of the negative electrode plate, there is a problem that the positive electrode plate is broken or bent. Furthermore, in the prior art of Patent Document 3, the positive electrode plate is heat-treated after pressing, but the processing temperature is defined by the melting point of polyvinylidene fluoride, and the crystal grains of the current collector are grown. In other words, the degree of expansion and contraction of the positive electrode plate is smaller than that of the negative electrode plate, and the positive electrode plate is broken or buckled.

  The present invention has been made in view of the above-described conventional problems, and heat treatment is performed at a temperature higher than the temperature at which the crystal grains of the positive electrode current collector grow, thereby improving the degree of expansion and contraction of the positive electrode plate and expanding the electrode plate during charge and discharge. For non-aqueous secondary batteries with high reliability by relaxing the stress applied to the positive electrode plate with a small degree of expansion and contraction caused by the difference in expansion between the positive electrode plate and the negative electrode plate during shrinkage, and suppressing the breakage or buckling of the positive electrode plate The object is to provide a positive electrode plate.

  In order to solve the above-described conventional problems, the method for producing a positive electrode plate for a non-aqueous secondary battery according to the present invention comprises kneading and dispersing at least an active material composed of a lithium-containing composite oxide, a conductive material, and a binder. A method for producing a positive electrode plate for a non-aqueous secondary battery in which a positive electrode mixture paint is applied on a positive electrode current collector to form a positive electrode mixture layer, wherein the positive electrode mixture paint is applied on the positive electrode current collector. Formed through a first step of pressing to a predetermined thickness after drying and a second step of heat-treating at or above the temperature at which the crystal grains of the positive electrode current collector grow by heating means after pressing It is.

  The method for producing a positive electrode plate for a non-aqueous secondary battery according to the present invention includes a first step of applying a positive electrode mixture paint onto a positive electrode current collector and drying it, followed by pressing to a predetermined thickness, and then heating after pressing. The degree of expansion and contraction of the positive electrode current collector is improved by following the second step of heat treatment at a temperature higher than the temperature at which the crystal grains of the positive electrode current collector grow by means, and the elongation of the negative electrode plate during charging and discharging is followed. It has the effect of suppressing breakage or buckling due to the difference in expansion and contraction, and it is possible to avoid a situation in which the non-aqueous secondary battery is short-circuited internally and causes thermal runaway due to heat generation.

Schematic of the manufacturing apparatus of the positive electrode plate for non-aqueous secondary batteries which concerns on one Example of this invention. Schematic of the manufacturing apparatus of the positive electrode plate for non-aqueous secondary batteries which concerns on another Example of this invention. Schematic of the manufacturing apparatus of the positive electrode plate for non-aqueous secondary batteries which concerns on another Example of this invention. Schematic of the manufacturing apparatus of the positive electrode plate for non-aqueous secondary batteries which concerns on another Example of this invention. Schematic of the manufacturing apparatus of the positive electrode plate for non-aqueous secondary batteries which concerns on another Example of this invention.

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 method for producing a positive electrode plate for a non-aqueous secondary battery that forms a mixture layer, the first step of applying a positive electrode mixture paint onto a positive electrode current collector and drying it, followed by pressing to a predetermined thickness; By forming through a second step of heat treatment at a temperature higher than the temperature at which the crystal grains of the positive electrode current collector are grown by the heating means after pressing, the degree of expansion and contraction of the positive electrode current collector is improved, and the negative electrode plate during charging and discharging Therefore, it is possible to prevent breakage or buckling due to the difference in the degree of expansion and contraction, and to avoid a situation in which the non-aqueous secondary battery is internally short-circuited and causes thermal runaway due to heat generation.

  In the second invention of the present invention, the heat treatment is performed by sequentially raising the temperature by using a plurality of heat sources to gradually increase the temperature, thereby suppressing wrinkles due to heat generated by rapidly heating the positive electrode plate. This makes it possible to prevent an increase in the group diameter after winding due to an increase in the thickness of the positive electrode plate due to wrinkles generated by heat.

  In the third invention of the present invention, the heat treatment is caused by rapidly heating the positive electrode plate by gradually raising the temperature using a plurality of heat sources and lowering the temperature in multiple stages using a cooling mechanism. By suppressing wrinkles due to heat, it is possible to prevent an increase in the diameter of the electrode group during winding due to an increase in the thickness of the positive electrode plate due to wrinkles generated by heat. Moreover, by cooling the temperature sequentially, it is not necessary to air-cool the positive electrode plate, and high-speed production is possible.

  According to a fourth aspect of the present invention, there is provided an apparatus for producing a positive electrode plate for a non-aqueous secondary battery in which a positive electrode mixture paint is applied on a positive electrode current collector to form a positive electrode mixture layer and pressed to a predetermined thickness. By gradually heating the positive electrode plate after the press and having a heating mechanism for heat treatment at a temperature higher than the temperature at which the crystal grains of the positive electrode current collector grow, by heating the positive electrode plate stepwise, Wrinkles due to heat generated by rapid heating of the positive electrode plate can be suppressed.

  In the fifth aspect of the present invention, the heating mechanism is configured by a plurality of heating rolls that sequentially raise the temperature, so that the heating to the positive electrode plate is performed in a multistage manner by the plurality of heating rolls. By performing this heating stepwise, it becomes possible to suppress wrinkles due to heat generated by rapid heating of the positive electrode plate.

  In the sixth aspect of the present invention, the cooling mechanism using a plurality of cooling rolls is added to the subsequent stage of the heating mechanism, so that the positive electrode plate is heated rapidly by performing heating to the positive electrode stepwise. It becomes possible to suppress wrinkles due to the heat generated by. In addition, by performing the temperature decrease step by step with a plurality of cooling rolls that gradually decrease the temperature, it becomes possible to suppress wrinkles due to heat generated by a sudden temperature change, and it is not necessary to air-cool the positive electrode plate. It becomes possible.

  In the seventh invention of the present invention, the heating mechanism is provided with a heating furnace for preheating the positive electrode plate in front of the heating roll, thereby preventing the rapid heating of the positive electrode plate by preheating the positive electrode plate. It is possible to suppress wrinkles due to heat generated in the positive electrode plate due to a sudden temperature change.

  According to an eighth aspect of the present invention, the cooling mechanism is provided after the cooling roll for lowering the temperature of the cooling mechanism, so that the temperature of the positive electrode plate is lowered stepwise to cause a sudden temperature change. It is possible to suppress wrinkles due to the generated heat and eliminate the need for air cooling of the positive electrode plate, thereby enabling high-speed production.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an apparatus for manufacturing a positive electrode plate for a non-aqueous secondary battery according to an embodiment of the present invention. The manufacturing apparatus shown in FIG. 1 sends out a positive electrode plate 4 for non-aqueous secondary batteries (hereinafter abbreviated as positive electrode plate 4), a low temperature heating roll 1 for applying heat treatment stepwise to the unwinding unit 10 and the positive electrode plate 4, The intermediate temperature heating roll 2, the high temperature heating roll 3, and the winding unit 11 for winding the positive electrode plate 4 are configured. Here, the positive electrode plate 4 is formed by applying a positive electrode mixture paint, which is a pasty active material, to a metal foil serving as a current collector, and drying and rolling. The positive electrode plate 4 is fed out from the unwinding unit 10 and passed through the low temperature heating roll 1 to be heated to a low temperature region. Next, the medium temperature heating roll 2 is passed to heat to the middle temperature range, and the high temperature heating roll 3 is further passed to heat to the high temperature range. Thus, after the heat treatment is applied to the positive electrode plate 4 stepwise, the heat treatment can be performed stepwise to a temperature at which the crystal grains of the positive electrode current collector wound up by the winding unit 11 grow. Furthermore, it is possible to suppress wrinkles due to heat of the positive electrode plate 4 generated by sudden heating, and to improve the degree of expansion and contraction of the positive electrode current collector.

  Moreover, as another manufacturing method of the present invention, a manufacturing apparatus having the configuration shown in FIG. 2 can be used. Specifically, the unwinding unit 10 for feeding out the positive electrode plate 4 for a non-aqueous secondary battery, and the positive electrode plate 4, a low temperature heating roll 1 for applying heat treatment in stages, a medium temperature heating roll 2, a high temperature heating roll 3, then cooling rolls 5, 6, 7 for cooling the positive electrode plate 4 in stages, and a positive electrode plate 4 It is comprised from the winding-up part 11 for winding up. Here, the positive electrode plate 4 is sent out from the unwinding unit 10 and heated to a low temperature range by passing through the low temperature heating roll 1, and then heated to a middle temperature range by passing through the intermediate temperature heating roll 2. Furthermore, it heats to a high temperature range by letting the high temperature heating roll 3 pass. In this way, heat treatment is applied to the positive electrode plate 4 stepwise to perform heat treatment step by step to a temperature at which the crystal grains of the positive electrode current collector grow, and then the cooling roll 5 to the cooling roll 6 are gradually lowered in temperature. The temperature of the positive electrode plate 4 is lowered stepwise by passing the cooling roll 7 and wound up by the winding unit 11 to suppress wrinkles caused by the heat of the positive electrode plate caused by a sudden temperature change. It is possible to improve the elasticity of the body. Further, since air cooling is not required, high speed production is possible.

  Further, as another manufacturing method of the present invention, a manufacturing apparatus having the configuration shown in FIG. 3 can be used. Specifically, the unwinding unit 10 for feeding out the positive electrode plate 4 for a non-aqueous secondary battery, the heating furnace 8 for preheating the positive electrode plate 4, the high-temperature heating roll 3 for applying heat treatment, and the positive electrode plate 4 are wound up. It is comprised from the winding-up part 11 for. Here, the positive electrode plate 4 is sent out from the unwinding unit 10, passed through the heating furnace 8, preheated, and then passed through the high-temperature heating roll 3. Thus, after heating to a high temperature range, it can wind in the winding part 11, and can heat-process in steps to the temperature which the crystal grain of a positive electrode electrical power collector grows. Furthermore, by applying preheating to the positive electrode plate 4, it is possible to suppress wrinkles due to the heat generated in the positive electrode plate 4 by rapid heating and to improve the degree of expansion and contraction of the positive electrode current collector.

  Further, as another manufacturing method of the present invention, a manufacturing apparatus having the configuration shown in FIG. 4 can be used. Specifically, the unwinding unit 10 for feeding out the positive electrode plate 4 for a non-aqueous secondary battery, and the positive electrode plate A heating furnace 8 for preheating 4, a high-temperature heating roll 3 for applying heat treatment, then cooling rolls 5, 6, 7 for cooling the positive electrode plate 4 in stages, and further for winding up the positive electrode plate 4. The winding part 11 is comprised. Here, the positive electrode plate 4 is sent out from the unwinding unit 10, passed through the heating furnace 8, preheated, then passed through the high-temperature heating roll 3, and the positive electrode plate 4 is heated to a high temperature region, so that the crystal of the positive electrode current collector Heat treatment is performed step by step up to the temperature at which the grains grow. Next, the temperature of the positive electrode plate 4 is lowered stepwise by passing the cooling roll 6 and the cooling roll 7 from the cooling roll 5 whose temperature has been lowered stepwise and winding the winding roll 11 at a steep temperature. It is possible to suppress wrinkles due to the heat of the positive electrode plate generated by the change and improve the degree of expansion and contraction of the positive electrode current collector. Further, since air cooling is not required, high speed production is possible.

Furthermore, another manufacturing method of the present invention can use the manufacturing apparatus having the configuration shown in FIG. 5. Specifically, the unwinding unit 10 that feeds out the positive electrode plate 4 and the heat treatment stepwise on the positive electrode plate 4. Low temperature heating roll 1 for adding, medium temperature heating roll 2, high temperature heating roll 3, then cooling furnace 9 and cooling roll 7 for cooling positive electrode plate 4 stepwise, and winding for winding positive electrode plate 4 The unit 11 is configured. Here, the positive electrode plate 4 is sent out from the unwinding unit 10 and heated to a low temperature range by passing through the low temperature heating roll 1, and then heated to a middle temperature range by passing through the intermediate temperature heating roll 2. Further, by passing through the high temperature heating roll 3 and heating to a high temperature region, the positive electrode plate 4 is subjected to heat treatment step by step, and the heat treatment is performed step by step to a temperature at which the crystal grains of the positive electrode current collector grow. Next, after passing through the cooling furnace 9, the cooling roll 7 is passed through and taken up by the take-up unit 11, whereby the temperature of the positive electrode plate 4 is increased stepwise, and wrinkles due to the heat of the positive electrode plate generated by sudden heating are caused. It is possible to suppress wrinkles due to heat of the positive electrode plate 4 caused by a sudden temperature change by cooling the positive electrode plate 4 in stages, and to improve the degree of expansion and contraction of the positive electrode current collector. Further, since air cooling is not required, high speed production is possible.

  Hereinafter, specific Example 1 will be described in more detail. An electrode mixture paint using composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then subjected to heat treatment by the manufacturing apparatus shown in FIG. Thus, a positive electrode plate for a non-aqueous secondary battery was produced. As a heat treatment method, the pressed positive electrode plate 4 is sent out from the unwinding unit 10, the temperature of the low temperature heating roll 1 is set to 80 ° C., the temperature of the medium temperature heating roll 2 is set to 140 ° C., and the temperature of the high temperature heating roll 3 is set to 200 ° C. In this state, the positive electrode plate 4 was passed and wound up by the winding unit 11. The positive electrode plate 4 prepared by applying heat treatment to the positive electrode plate 4 in a multistage manner in this manner was used as Example 1.

  An electrode mixture paint containing composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then subjected to heat treatment by the manufacturing apparatus shown in FIG. Thus, the positive electrode plate 4 was produced. As a heat treatment method, the pressed positive electrode plate 4 is sent out from the unwinding unit 10, the temperature of the low temperature heating roll 1 is set to 80 ° C., the temperature of the medium temperature heating roll 2 is set to 140 ° C., and the temperature of the high temperature heating roll 3 is set to 200 ° C. In this state, the positive electrode plate 4 is allowed to pass through and heat treatment is applied to the positive electrode plate 4 in a multistage manner, and then the temperature of the cooling roll 5 is 140 ° C., the temperature of the cooling roll 6 is 80 ° C., and the temperature of the cooling roll 7 is 30 ° C. The positive electrode plate 4 was allowed to pass through in the state set to, and was wound up by the winding unit 11. The positive electrode plate 4 prepared by applying heat treatment to the positive electrode plate 4 in multiple stages and then lowering the temperature in multiple stages was taken as Example 2.

  An electrode mixture paint containing composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then subjected to heat treatment by the manufacturing apparatus shown in FIG. Thus, the positive electrode plate 4 was produced. As a heat treatment method, the positive electrode plate 4 after pressing is sent out from the unwinding unit 10 and passed through the positive electrode plate 4 with the temperature of the heating furnace 8 set to 120 ° C. and the temperature of the high-temperature heating roll 3 set to 200 ° C. The take-up part 11 was wound up. The positive electrode plate 4 thus prepared by applying heat treatment to the positive electrode plate 4 in a multistage manner was taken as Example 3.

  An electrode mixture paint using composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then subjected to heat treatment by the manufacturing apparatus shown in FIG. Thus, the positive electrode plate 4 was produced. As a heat treatment method, the positive electrode plate 4 after pressing is sent out from the unwinding unit 10, and the positive electrode plate 4 is passed through the positive electrode plate 4 with the temperature of the heating furnace 8 set to 120 ° C. and the temperature of the high-temperature heating roll 3 set to 200 ° C. After heat-treating the plate 4 in a multi-step manner, the positive electrode plate 4 is passed with the temperature of the cooling roll 5 set to 140 ° C., the temperature of the cooling roll 6 set to 80 ° C., and the temperature of the cooling roll 7 set to 30 ° C. And wound up by the winding unit 11. The positive electrode plate 4 prepared by applying the heat treatment to the positive electrode plate 4 in multiple stages and then decreasing the temperature in multiple stages was taken as Example 4.

  An electrode mixture paint containing composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then subjected to heat treatment by the manufacturing apparatus shown in FIG. Thus, the positive electrode plate 4 was produced. As a heat treatment method, the pressed positive electrode plate 4 is sent out from the unwinding unit 10, the temperature of the low temperature heating roll 1 is set to 80 ° C., the temperature of the medium temperature heating roll 2 is set to 140 ° C., and the temperature of the high temperature heating roll 3 is set to 200 ° C. After passing through the positive electrode plate 4 in such a state and applying heat treatment to the positive electrode plate 4 in a multi-step manner, the positive electrode plate 4 is set with the temperature of the cooling furnace 9 set to 120 ° C. and the temperature of the low-temperature cooling roll 7 set to 40 ° C. Was taken up by the take-up unit 11. The positive electrode plate 4 prepared by applying heat treatment to the positive electrode plate 4 in multiple steps and then lowering the temperature in multiple steps was taken as Example 5.

(Comparative Example 1)
An electrode mixture paint having composite lithium oxide as a positive electrode active material is applied to an aluminum foil as a positive electrode current collector, dried and pressed to a thickness of 165 μm, and then heat treated by a heating roll set at 200 ° C. The positive electrode plate prepared by adding was used as Comparative Example 1.

(Comparative Example 2)
Comparative Example 2 is a positive electrode plate prepared by applying an electrode mixture paint using composite lithium oxide as a positive electrode active material to an aluminum foil as a positive electrode current collector and drying it to make a thickness of 165 μm. It was.

  As an evaluation of the thermal wrinkle of the positive electrode plate prepared under the above conditions, the thickness variation of the positive electrode plate in Examples 1 to 5 and Comparative Examples 1 and 2 was measured. Furthermore, the positive electrode plate was wound together with the negative electrode plate and the separator, and the results of evaluation of the defect rate such as breakage in the electrode plate are shown in (Table 1).

  As is apparent from the results of (Table 1), in Examples 1 and 2 in which heat treatment is performed in multiple steps, wrinkles due to heat generated by the heat treatment are suppressed, and the degree of expansion and contraction of the positive electrode plate is improved. While the occurrence of defects due to electrode plate breakage is prevented, in Comparative Example 1, since rapid heating is performed by a single heating roll, the wrinkles due to heat increase, and no comparative heat treatment is applied. In No. 2, defects such as electrode plate breakage have occurred. Based on the above results, it is possible to suppress wrinkles due to the heat of the positive electrode plate that is generated by rapid heating by applying heat treatment to the positive electrode plate in multiple stages, and to improve the degree of expansion and contraction of the positive electrode current collector. It is possible to suppress defects due to bending or the like.

The method for manufacturing a positive electrode plate for a non-aqueous secondary battery according to the present invention improves the elasticity of the positive electrode plate for a non-aqueous secondary battery, and allows the elasticity of the electrode plate to expand and contract by following the elasticity of the negative electrode plate. It is possible to relieve the stress generated due to the difference between them and to suppress wrinkles due to heat generated by heat treatment, which is useful as a method for producing a positive plate for a non-aqueous secondary battery.

DESCRIPTION OF SYMBOLS 1 Low temperature heating roll 2 Medium temperature heating roll 3 High temperature heating roll 4 Positive electrode plate for non-aqueous secondary batteries 5, 6, 7 Cooling roll 8 Heating furnace 9 Cooling furnace 10 Unwinding part 11 Winding part

Claims (8)

  A non-aqueous secondary that forms a positive electrode mixture layer 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 onto a positive electrode current collector A method for producing a positive electrode plate for a battery, comprising: a first step of applying the positive electrode mixture paint onto a positive electrode current collector and drying the pressed plate to a predetermined thickness; and pressing the positive electrode collector by a heating means after pressing. A method for producing a positive electrode plate for a non-aqueous secondary battery, characterized in that the positive electrode plate is formed through a second step in which heat treatment is performed at a temperature higher than a temperature at which crystal grains of an electric conductor grow.   The method for producing a positive electrode plate for a non-aqueous secondary battery according to claim 1, wherein the heat treatment is performed by gradually increasing the temperature using a plurality of heat sources.   2. The method of manufacturing a positive electrode plate for a non-aqueous secondary battery according to claim 1, wherein the heat treatment is performed by gradually raising the temperature using a plurality of heat sources and lowering the temperature in multiple stages using a cooling mechanism. .   An apparatus for manufacturing a positive electrode plate for a non-aqueous secondary battery, in which a positive electrode mixture paint is applied on a positive electrode current collector to form a positive electrode mixture layer and pressed to a predetermined thickness, wherein the non-aqueous secondary battery after the pressing An apparatus for producing a positive electrode plate for a non-aqueous secondary battery, comprising a heating mechanism that heat-treats the positive electrode plate for a battery gradually at a temperature higher than a temperature at which crystal grains of the positive electrode current collector grow.   The apparatus for manufacturing a positive electrode plate for a non-aqueous secondary battery according to claim 4, wherein the heating mechanism is configured by a plurality of heating rolls that are sequentially heated.   The apparatus for producing a positive electrode plate for a non-aqueous secondary battery according to claim 4, wherein a cooling mechanism using a plurality of cooling rolls is added to the subsequent stage of the heating mechanism.   The apparatus for producing a positive electrode plate for a non-aqueous secondary battery according to claim 4, wherein a heating furnace for preheating the heating mechanism is provided in front of the heating roll.   The apparatus for producing a positive electrode plate for a non-aqueous secondary battery according to claim 6, wherein a cooling furnace is provided in a preceding stage of a cooling roll for lowering the temperature of the cooling mechanism.

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