JPH07130394A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

PURPOSE:To minimize any short-circuit in a battery arising in manufacturing the electrode without marring the energy density of the battery, restrain self- discharge, improve the cycle property and greatly increase the yield and reliability of a product. CONSTITUTION:Taking for example, resin coating is applied to both ends 11d, 11e in the cross direction of a negative electrode 11 at a preset width from the end faces (a), (b) to form a resin layer 21. A positive electrode is also coated with a similar resin layer 21 to form a resin layer 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte secondary battery, and more particularly to the structure of a wound electrode body which is a constituent element thereof.

[0002]

2. Description of the Related Art Recent remarkable advances in electronic technology have made electronic devices smaller and lighter one after another. Along with this, batteries, which are used as mobile power sources, are required to be smaller and lighter and have high energy density.

Conventionally, an aqueous solution type secondary battery such as a lead battery or a nickel-cadmium battery has been mainly used as a secondary battery for general use. However, although these aqueous secondary batteries have excellent cycle characteristics, they cannot be said to be sufficiently satisfactory in terms of battery weight and energy density.

Therefore, recently, a material capable of doping and dedoping lithium ions such as lithium, a lithium alloy and a carbon material is used as a negative electrode, and a lithium composite oxide such as a lithium cobalt composite oxide is used as a positive electrode. Research and development of a non-aqueous electrolyte secondary battery using a battery have been actively conducted. This battery has a high battery voltage, a high energy density, and excellent cycle characteristics.

Taking a cylindrical non-aqueous electrolyte secondary battery as an example, a conventional non-aqueous electrolyte secondary battery is formed by applying a positive electrode active material on both sides of a strip-shaped positive electrode current collector 101a as shown in FIG. Positive electrode 101 comprising positive electrode mixture layers 101b and 101c
And a negative electrode 102 composed of a negative electrode mixture layer 102b and 102c formed by applying a negative electrode active material on both surfaces of a strip-shaped negative electrode current collector 102a, and wound around a separator 103 made of a polypropylene film. Electrode body 104
In addition, the wound electrode body 104 is housed in a battery container with insulators placed above and below the wound electrode body 104.

[0006]

However, in the conventional non-aqueous electrolyte secondary battery, in the electrode portion such as the wound electrode body 104, which is a component thereof, as the separator, more electrodes are filled inside the battery. Then, a microporous film is used to increase the battery capacity. However, it cannot be said that the mechanical strength of this film is sufficient, and when the positive and non-electrodes are superposed and, for example, a spiral wound electrode body is produced, the electrode active material (positive / negative electrode composite) separated from the electrode is In many cases, the above-mentioned separator is damaged and broken by the agent). When the separator breaks like this,
Contact between the positive electrode and the negative electrode, so-called internal short circuit of the battery occurs. As described above, a battery having an internal battery short circuit has a large self-discharge, and in the case of an assembled battery, there are problems such as a large deterioration of cycle characteristics during charging and discharging.

In order to reduce the internal short-circuit rate, peeling of the electrode active material (positive / negative electrode mixture) is prevented, and the mechanical strength of the separator is increased so that the peeled substance is present between the separator and the electrode. It is necessary to make the separator difficult to tear even if it is pinched. In order to increase the mechanical strength of the separator, it is conceivable to increase the thickness of the separator and use a film having high mechanical strength as the separator. Increasing the thickness of the separator causes a decrease in the energy density of the battery, which is difficult to employ. Therefore, it is essential to develop a film having a small film thickness and high mechanical strength, but at present, the development of such a film is very difficult.

The present invention has been made in view of the above-mentioned various problems, and an object of the present invention is to minimize a battery internal short circuit that occurs during the production of an electrode portion without impairing the energy density of the battery. The present invention provides a non-aqueous electrolyte secondary battery, which can suppress the self-discharge, improve the cycle characteristics, and significantly improve the product yield and reliability. Especially.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a non-aqueous electrolyte solution having an electrode portion formed by stacking a positive electrode and a negative electrode, which are coated with an electrode mixture on both front and back surfaces of a strip-shaped metal foil, with a separator interposed therebetween. In the secondary battery, at least one end of the positive electrode or the negative electrode in the width direction is covered with a resin to form a resin layer.

In this case, the electrode part may be formed as a spirally wound electrode body.

Further, in this case, the width of the end covered with the resin layer of the positive electrode or the negative electrode is set to 0 to 5 mm, and is formed to be 12% or less of the entire width of the positive electrode or the negative electrode.

[0012]

In the non-aqueous electrolyte secondary battery according to the present invention,
By coating the resin layer 21 with a required width at the widthwise end portions of the positive and negative electrodes where the electrode active material (positive / negative electrode mixture) is easily peeled off at the time of production, The peeling of the electrode active material is prevented, and the separator is less likely to be broken. Therefore, the occurrence rate of the battery internal short circuit caused by the contact between the positive electrode and the negative electrode of the electrode portion inside the battery is surely reduced.

[0013]

EXAMPLES Examples of the non-aqueous electrolyte secondary battery according to the present invention will be described below with reference to the drawings.

The non-aqueous electrolyte secondary battery according to this embodiment is
As shown in FIG. 1, a spirally wound electrode body 1,
It is composed of an upper lid portion 2 and a battery container portion 3 that houses the spirally wound electrode body 1.

In the wound electrode body 1, a negative electrode current collector 11a made of copper is coated with a negative electrode mixture 11b and 11c made of a carbon material (for example, KH carbon) capable of doping and dedoping lithium, or metallic lithium. A negative electrode 11 formed by bonding together a positive electrode current collector 12a made of Al and a positive electrode 12 formed by applying a positive electrode mixture 12b and 12c made of LiCoO ₂ which is a composite oxide of lithium and a transition metal to polyethylene. Alternatively, a plurality of sets are wound and arranged via a separator 13 made of polypropylene as a material.

Here, regarding the negative electrode 11 and the positive electrode 12, taking the negative electrode 11 as an example, as shown in FIG.
End faces a are formed on both ends 11d and 11e in the width direction of the negative electrode 11.
And a resin layer 2 coated with a resin having a predetermined width d from b
1 is formed. The positive electrode 12 is also coated with a resin in the same manner as the negative electrode 11 to form a resin layer 21.

The material for the resin layer 21 is preferably insoluble in a non-aqueous electrolyte solution. Some examples include polyolefin resins such as polyethylene, polypropylene and polybutylene, polystyrene, and styrene-acrylonitrile copolymer. Polyolefin resin such as, polyacrylic resin such as polyethylmethacrylate, polymethylmethacrylate, etc., pyrivinyl resin such as polyvinyl acetate, polyvinyl butyrate, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoropropylene / hexafluoro resin Examples include single and plural resins selected from fluororesins such as propylene copolymers.

By the way, in FIG. 2, when the coating portion of the resin layer 21 is only the both end faces a and b in the width direction of the negative electrode 11 (the same applies to the positive electrode 12), that is, when d = 0, the positive / negative electrode mixture is formed. The peeling prevention function of is not fully exerted. Further, the coating portion of the resin layer 21 is 5 m from the end surface a or b.
If it exceeds m, that is, if d> 5 mm, the area of the electrodes involved in the charge / discharge reaction of the battery decreases, which is not preferable from the viewpoint of increasing the energy density of the battery.

Therefore, the appropriate value of the width d is 0 to
It is considered to be within 5 mm, preferably within 0.5 to 2 mm. Further, this width d is 12 times the total width of the negative electrode 11.
% Or less is desirable.

The negative electrode 11 of the above-mentioned wound electrode body 1 contains Ni.
Is connected to the negative electrode lead 14, and the negative electrode lead 14 is connected to the battery container 3 to be in conduction. Also,
A positive electrode lead 15 made of pure Al is connected to the positive electrode 12, and the positive electrode lead 15 is connected to the upper lid portion 2 and is electrically connected.

The upper lid portion 2 is a disk-shaped member made of iron having a bulged central portion, and is connected to the positive electrode lead 15 for electrical conduction. That is, the upper lid portion 2 has a function as a positive electrode terminal.

The battery container 3 is a synthetic resin plate or iron plate of polyethylene or polypropylene having a high specific strength, plated with Ni having a high thermal conductivity, has a cylindrical shape, and has an opening 3a at its upper part. Have. This opening 3a
Therefore, the spirally wound electrode body 1 is arranged via a polyethylene sheet, and insulating plates 17 are provided on both upper and lower surfaces of the spirally wound electrode body 1.
Is installed. Then, using lithium salt as an electrolyte,
A non-aqueous electrolyte solution obtained by dissolving this in a non-aqueous solvent is provided in the opening 3a
From above, the wound electrode body 1 is dipped, and the upper lid portion 2 is caulked and fixed to the opening portion 3a through the insulating gasket 18 to be closed to form the non-aqueous electrolyte secondary battery according to the above-described embodiment. .

In order to manufacture the non-aqueous electrolyte secondary battery according to the above example, first, 0.5 mol of lithium carbonate as a positive electrode active material and 1 mol of cobalt carbonate were mixed, and the mixture was kept in air at 900 ° C. for 5 hours. It is calcined to obtain LiCoO ₂ . 91 parts by weight of LiCoO ₂ thus obtained, 6 parts by weight of graphite as a conductive agent, and PVDF3 as a binder
Part by weight is mixed to obtain a positive electrode mixture. Then, this positive electrode mixture is dispersed in N-methylpyrrolidone as a solvent to form a slurry. A strip-shaped aluminum foil having a thickness of 30 μm is used as a positive electrode current collector, and the positive electrode mixture (slurries) 12b and 12c are uniformly applied to both surfaces of the positive electrode current collector 12a, dried and then compressed using a roll press machine. It shape | molds and the strip | belt-shaped positive electrode 12 is produced.

Next, using petroleum pitch as a starting material,
This is introduced with 10% to 20% of a functional group containing oxygen (so-called oxygen cross-linking) and then heat-treated at 1000 ° C. in an inert gas stream to obtain a non-graphite carbon material powder having properties similar to glassy carbon.

The carbon material powder thus obtained was used as a negative electrode active substance, and 90 parts by weight of this was mixed with 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder to prepare a negative electrode mixture. Then, this negative electrode mixture is dispersed in N-methylpyrrolidone as a solvent to form a slurry. A strip-shaped copper foil having a thickness of 20 μm was used as the negative electrode current collector, and the negative electrode mixture (slurries) 11b and 11 were formed on both surfaces of the negative electrode current collector 11a.
c is uniformly applied and dried, and then compression-molded using a roll press machine to produce a strip-shaped negative electrode 11.

Then, as shown in FIG. 2, a resin solution is applied to both ends 11d and 11e in the width direction of the negative electrode 11 (the same applies to the positive electrode 12) using a nozzle type spray coater.
That is, first, the resin solution is applied over the entire end faces a and b, and then the end faces a and b are provided on the surfaces of the negative electrode mixtures 11b and 11c with a predetermined width d over the entire length of the negative electrode 11. Over the resin layer 2 by applying the resin solution so as to form a continuous layer with the resin solution applied on the end faces a and b.
1 is formed.

The composition of the resin solution is 26% of KF polymer / PVDF (trade name, manufactured by Kureha Chemical Co., Ltd.) and 11 of poly (ethyl methacrylate) in a wet weight ratio.
%, And acetone is 63%. As a method for forming the resin layer 21, a method of applying the resin solution by various coating methods such as brush coating and a method using a roll coater, or a dry powder of the resin is evenly applied to the electrode end portion. Then, a method of fusion bonding may be used.

A battery core 16 made of aluminum is used, and the negative electrode 11 and the positive electrode 12 are placed inside the battery core 16 with a separator 13 made of a microporous polypropylene film interposed therebetween. A spirally wound electrode body 1 is obtained by spirally winding a large number of times.

The spirally wound electrode part 1 thus manufactured is housed in a battery container 3 made of iron plated with nickel. Then, the insulating plates 17 are installed on both upper and lower surfaces of the wound electrode unit 1,
In order to collect the current of the negative electrode 11 and the positive electrode 12, a negative electrode lead 14 made of nickel is led out from the negative electrode current collector and welded to the battery container 3, and a positive electrode lead 15 made of aluminum is led out of the positive electrode current collector and an upper lid. Weld to part 2.

When nickel plating is applied to the battery container 3 to form a nickel plating layer, if the nickel plating is applied to the joint portion of the battery container 3, there is a problem that welding is difficult at the time of joining. In addition, it is preferable that the joint portion is masked and the battery case 3 is nickel-plated.

Then, 1 mL of LiPF ₆ was added to a mixed solvent of equal volume of propylene carbonate and diethyl carbonate.
The nonaqueous electrolytic solution dissolved at a ratio of mol / l is injected from the opening 3a of the battery container 3 to impregnate the wound electrode body 1.

Then, the upper lid portion 2 is caulked and fixed to the battery container 3 via the insulating gasket 18 coated with afphalt, whereby the non-aqueous electrolyte secondary battery according to the above-mentioned embodiment is completed.

In the non-aqueous electrolyte secondary battery according to this example, the positive and negative electrodes 12 where the electrode active materials (the positive electrode mixture 12b and 12c, the negative electrode mixture 11b and 11c) are easily peeled off during the production. By covering both ends a and b in the width direction of 11 and 11 with the resin layer 21 with a required width d, peeling of the electrode active material at the time of manufacturing the electrode portion is prevented, and the separator 13 is less likely to be broken. Become. Therefore, the occurrence rate of the battery internal short circuit caused by the contact between the positive electrode 12 and the negative electrode 11 of the electrode portion 1 inside the battery can be surely reduced.

Therefore, it is possible to greatly improve the battery performance such as energy density and cycle characteristics, and further, it is possible to save the labor at the time of inspecting the product and significantly improve the yield and reliability of the product. Become.

In this embodiment, a spirally wound spirally wound electrode is used as the electrode portion, but the spirally wound electrode is not limited to the spirally wound electrode in the present invention. An electrode portion formed by folding the negative electrode through the separator, an electrode portion formed by stacking a large number of rectangular positive and negative electrodes through the separator, and the like,
Any electrode part can be used.

Here, one experimental example will be shown. This experimental example is different from the five types of samples in which the width d of the resin layer 21 covering the positive and negative electrodes 12 and 11 (in some cases, the resin layer is not formed) is different in the non-aqueous electrolyte secondary battery according to the above example. The non-aqueous electrolyte secondary battery as a comparative example in which the above-mentioned resin layers are not formed on the positive and negative electrodes 12 and 11 was used.

As the above five kinds of samples, sample 1
Is d = 0.5 mm for both positive and negative electrodes 12 and 11, and sample 2 is d = 2.0 m for both positive and negative electrodes 12 and 11.
m, sample 3 has d = for both positive and negative electrodes 12 and 11.
5.0 mm, sample 4 has d = 2 mm only on the negative electrode 11, and the resin layer 21 is not formed on the positive electrode 12, and sample 5 has d = only on the positive electrode 12 contrary to the sample 4. The thickness was set to 2 mm, and the negative electrode 11 on which the resin layer 21 was not formed was used.

In the above experimental example, the above seven types of batteries were used
The battery voltage was measured after charging for 8 hours at a current of 0 mA and an upper limit voltage of 4.15 V and storing it in an atmosphere of 23 ° C. for 1 month. At the time of this measurement, it was determined that a battery having a voltage of 4.00 V or less had an internal battery short circuit. Randomly extract 10 batteries of 4.00V or more,
A constant current discharge capacity test was performed at a final voltage of 2.75 V at 200 mA. The results are shown in Table 1 below.

[0039]

[Table 1]

As shown in Table 1, in the comparative example, internal short-circuit occurred in all 10 batteries, while in Samples 4 and 5, two internal short-circuits occurred, and one internal short-circuit occurred. No occurrence occurred in Samples 1 to 3. Regarding the discharge capacity, Samples 1 to 5 each showed a value 7 to 72 mAh lower than 950 mAh of the comparative example. Therefore, it can be seen that in the non-aqueous electrolyte secondary batteries according to the above-mentioned examples, the rate of occurrence of battery internal short circuit is significantly low, and self-discharge is unlikely to occur.

[0041]

EFFECTS OF THE INVENTION According to the non-aqueous electrolyte secondary battery of the present invention, an electrode portion formed by stacking a positive electrode and a negative electrode, which are coated with an electrode mixture on both front and back surfaces of a strip-shaped metal foil, with a separator interposed therebetween. In the non-aqueous electrolyte secondary battery having, since at least one end of the positive electrode or the negative electrode in the width direction is coated with a resin to form a resin layer, a battery internal short circuit that occurs during the production of the electrode part, The energy density of the battery can be minimized without deteriorating, self-discharge can be suppressed, cycle characteristics can be improved, and product yield and reliability can be greatly improved. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing the structure of a non-aqueous electrolyte secondary battery according to an example of the present invention.

FIG. 2 is a perspective view schematically showing a state before winding of a negative electrode current collector which is a constituent element of a wound electrode body of the non-aqueous electrolyte secondary battery according to the present embodiment.

FIG. 3 is a cross-sectional view schematically showing a wound electrode body of a conventional non-aqueous electrolyte secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Winding electrode body 2 ... Upper lid part 3 ... Battery container part 11 ... Negative electrode 12 ... Positive electrode 13 ... Separator 21 ... Resin layer

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[Procedure amendment]

[Submission date] December 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Taking a cylindrical non-aqueous electrolyte secondary battery as an example, a conventional non-aqueous electrolyte secondary battery is formed by applying a positive electrode active material on both sides of a strip-shaped positive electrode current collector 101a as shown in FIG. And a positive electrode 101 composed of positive electrode mixture layers 101b and 101e,
A wound electrode body in which a negative electrode 102 composed of a negative electrode mixture layer 102b and 102c formed by coating a negative electrode active material on both surfaces of a strip-shaped negative electrode current collector 102a is wound with a separator 103 made of a polypropylene film interposed therebetween. 104,
The wound electrode body 104 is housed in a battery container with insulators placed on the top and bottom.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

However, in the conventional non-aqueous electrolyte secondary battery, in the electrode portion such as the wound electrode body 104, which is a component thereof, as the separator, more electrodes are filled inside the battery. Then, a microporous film is used to increase the battery capacity. However, it cannot be said that the mechanical strength of this film is sufficient, and when the positive and negative electrodes are superposed and, for example, a spiral wound electrode body is produced, the electrode active material (positive / negative electrode composite) separated from the electrode is removed. In many cases, the above-mentioned separator is damaged and broken by the agent). When the separator breaks like this,
Contact between the positive electrode and the negative electrode, so-called internal short circuit of the battery occurs. As described above, a battery having an internal battery short circuit has a large self-discharge, and in the case of an assembled battery, there are problems such as a large deterioration of cycle characteristics during charging and discharging.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

In the wound electrode body 1, a negative electrode current collector 11a made of copper is coated with a negative electrode mixture 11b and 11c made of a carbon material (for example, KH carbon) capable of doping and dedoping lithium, or metallic lithium. A negative electrode 11 formed by bonding together a positive electrode current collector 12a made of Al and a positive electrode 12 formed by applying a positive electrode mixture 12b and 12c made of LiCoO ₂ which is a composite oxide of lithium and a transition metal to polyethylene. Alternatively, a plurality of windings are arranged via a separator 13 made of polypropylene as a material.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

The material of the resin layer 21 is preferably insoluble in the non-aqueous electrolyte, and some examples include polyolefin resins such as polyethylene, polypropylene and polybutylene, polystyrene and styrene-acrylonitrile copolymer. Polyolefin resin such as, polyacrylic resin such as polyethylmethacrylate, polymethylmethacrylate, etc., pyrivinyl resin such as polyvinyl acetate, polyvinyl butyrate, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoropropylene / hexafluoro resin Examples include single and plural resins selected from fluororesins such as propylene copolymers.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

The battery container portion 3 is made of an iron plate plated with Ni, has a cylindrical shape, and has an opening 3 at the top thereof.
a. The wound electrode body 1 is arranged from the opening 3a via a polyethylene sheet, and insulating plates 17 are provided on both upper and lower surfaces of the wound electrode body 1. Then, a lithium salt is used as an electrolyte, and a non-aqueous electrolytic solution obtained by dissolving this in a non-aqueous solvent is injected through the opening 3a to immerse the spirally wound electrode body 1, and the upper lid portion 2 is covered with the insulating gasket 18 in the opening 3a. The non-aqueous electrolyte secondary battery according to the above-mentioned embodiment is constituted by caulking, fixing and closing.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

In order to manufacture the non-aqueous electrolyte secondary battery according to the above-mentioned embodiment, first, as a positive electrode active material, lithium carbonate 0.
5 mol and 1 mol of cobalt carbonate are mixed and baked in air at 900 ° C. for 5 hours to obtain LiCoO ₂ . 91 parts by weight of LiCoO ₂ thus obtained, 6 parts by weight of graphite as a conductive agent, and 3 parts by weight of PVDF as a binder are mixed to form a positive electrode mixture. Then, this positive electrode mixture is dispersed in N-methylpyrrolidone as a solvent to form a slurry. A strip-shaped aluminum foil having a thickness of 30 μm is used as the positive electrode current collector, and the positive electrode mixture (slurries) 12b and 12e are uniformly applied to both surfaces of the positive electrode current collector 12a, dried and then compressed using a roll press machine. It shape | molds and the strip | belt-shaped positive electrode 12 is produced.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

The carbon material powder thus obtained was used as a negative electrode active material, and 90 parts by weight of this was mixed with 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder to prepare a negative electrode mixture. Then, this negative electrode mixture is dispersed in N-methylpyrrolidone as a solvent to form a slurry. A band-shaped copper foil having a thickness of 20 μm was used as the negative electrode current collector, and the negative electrode mixture (slurries) 11b and 11c were formed on both surfaces of the negative electrode current collector 11a.
Is uniformly applied and dried, and then compression-molded using a roll press machine to produce a strip-shaped negative electrode 11.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Here, one experimental example will be shown. This experimental example is different from the five types of samples in which the width d of the resin layer 21 covering the positive and negative electrodes 12 and 11 (in some cases, the resin layer is not formed) is different in the non-aqueous electrolyte secondary battery according to the above example. The non-aqueous electrolyte secondary battery as a comparative example in which the above-mentioned resin layers are not formed on the positive and negative electrodes 12 and 11 was used. For each of the above 6 types of batteries, 500 batteries were produced.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

In the above experimental example, the six types of batteries described above were used
The battery voltage was measured after the battery was charged for 8 hours under a charging condition of an upper limit voltage of 4.15 V with a current of 0 mA and stored in an atmosphere of 23 ° C. for one month. At the time of this measurement, it was determined that a battery having a voltage of 4.00 V or less had an internal battery short circuit. Randomly extract 10 batteries of 4.00V or more,
A constant current discharge capacity test was performed at a final voltage of 2.75 V at 200 mA. The results are shown in Table 1 below.

Claims (3)

[Claims] 1. A non-aqueous electrolyte secondary battery having an electrode portion formed by stacking a positive electrode and a negative electrode, which are coated with an electrode mixture on both front and back surfaces of a strip-shaped metal foil, with a separator interposed therebetween, at least a positive electrode or a negative electrode. One end in the width direction of the non-aqueous electrolyte secondary battery is characterized by being coated with a resin to form a resin layer. 2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the electrode portion is a spirally wound electrode body that is spirally wound. 3. The width of the end portion coated with the resin layer of the positive electrode or the negative electrode is 0 to 5 mm, and is 12% or less of the total width of the positive electrode or the negative electrode. The non-aqueous electrolyte secondary battery described.