JP2012204335A - Nonaqueous electrolyte secondary battery and method for manufacturing nonaqueous electrolyte secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a nonaqueous electrolyte secondary battery capable of preventing heat generation even when a part of a positive electrode does not face a negative electrode; and a method for manufacturing the nonaqueous electrolyte secondary battery.SOLUTION: A nonaqueous electrolyte secondary battery comprises: a negative electrode; a positive electrode arranged to face the negative electrode at at least a part the positive electrode; and a porous separator interposed between the positive electrode and the negative electrode and having a pore. The positive electrode has a facing region that faces the negative electrode and a non-facing region that does not face the negative electrode, and a pore blocking part where the pore is blocked is formed in the entire region corresponding to the non-facing region in the separator.

Description

  The present invention relates to a non-aqueous electrolyte secondary battery and a method for manufacturing the same.

  A non-aqueous electrolyte secondary battery is known as a rechargeable secondary battery. In particular, lithium ion secondary batteries are attracting attention because of their high energy density and high battery capacity. The nonaqueous electrolyte secondary battery includes a positive electrode in which a positive electrode active material layer is provided on at least a part of a positive electrode current collector, and a negative electrode in which a negative electrode active material layer is provided on at least a part of the negative electrode current collector Are opposed to each other with a separator interposed therebetween.

  In a nonaqueous electrolyte secondary battery, metal ions in the electrolyte may be deposited on the negative electrode during charging. For example, in a lithium ion secondary battery, it may be deposited as dendritic lithium. When a metal (for example, dendritic lithium) deposited on the negative electrode comes into contact with the opposing positive electrode, the battery generates heat due to an internal short circuit or a chemical reaction. Due to this heat generation, the temperature of the battery rises, and in the worst case, the battery may burst or ignite.

  A technique for suppressing lithium electrodeposition is described in Patent Document 1 (Japanese Patent Laid-Open No. 6-76860). Patent Document 1 describes a secondary battery in which a hole in a separator portion facing a peripheral portion of a positive electrode plate is crushed. This describes that the membrane resistance of the separator is increased, the charge / discharge reaction at the periphery of the electrode plate is suppressed, and the electrodeposition of lithium on the negative electrode is suppressed.

  Further, Patent Document 2 (Japanese Patent Laid-Open No. 2007-250319) has an object to provide a stacked secondary battery having excellent reliability in which a separator covering an electrode is not broken and an internal short circuit does not occur. The technology is described. In the stacked secondary battery of Patent Document 2, at least one of the positive electrode or the negative electrode is covered with a separator, and a hole blocking portion is provided at a portion facing the peripheral edge of the positive electrode or the negative electrode of the separator. It is characterized by having. It is described that the hole closing portion is formed by intermittently welding and joining two separators, thereby preventing wrinkles from forming and forming a bag-like separator.

Japanese Patent Laid-Open No. 6-76860 JP 2007-250319 A

  Usually, in a non-aqueous electrolyte secondary battery, the positive electrode and the negative electrode are formed in a substantially matching shape, and are generally opposed to each other with their electrode ends aligned. However, the positive electrode may protrude from the negative electrode and may have a region where the positive electrode does not face the negative electrode, rather than being completely aligned and facing each other. When such a non-aqueous electrolyte secondary battery is charged, metal ions supplied from the positive electrode may partially become excessive with respect to the capacitance allowed by the negative electrode, and metal may be deposited on the negative electrode.

  1A, FIG. 1B, FIG. 1C, FIG. 2A, FIG. 2B, and FIG. 2C show a case where a metal is formed on the negative electrode when the nonaqueous electrolyte secondary battery has a region where the positive electrode and the negative electrode are not opposed to each other. It is explanatory drawing for demonstrating a mode that deposits. As shown in FIGS. 1A to 1C, in the nonaqueous electrolyte secondary battery, a positive electrode 101 and a negative electrode 102 are arranged to face each other with a separator 103 interposed therebetween. The space between the positive electrode 101 and the negative electrode 102 is filled with a nonaqueous electrolyte. As the separator 103, a porous material is used so that metal ions in the nonaqueous electrolyte can pass therethrough. The positive electrode 101 protrudes at least partially from the negative electrode 102, and has a facing region facing the negative electrode 102 and a non-facing region not facing the negative electrode 102.

  When such a non-aqueous electrolyte secondary battery is charged, metal ions are supplied from the positive electrode into the electrolyte, and the metal ions in the non-aqueous electrolyte move to the negative electrode 102 side. At this time, metal ions may be excessive with respect to the negative electrode capacity in at least a part of the negative electrode, and the metal 104 may be deposited at the end of the negative electrode 102. Therefore, the metal 104 is easily generated or grown at the end of the negative electrode 102. As a result, as shown in FIGS. 2A, 2B, and 2C, the metal 104 may penetrate the separator 103 and come into contact with the positive electrode 101. When the metal 104 deposited on the negative electrode 102 comes into contact with the positive electrode 101, heat is generated as described above.

  Therefore, the object of the present invention is to prevent the growth of the metal deposited from the negative electrode or the contact between the metal deposited from the negative electrode and the positive electrode even when the positive electrode and the negative electrode are not opposed to each other. An object of the present invention is to provide a non-aqueous electrolyte secondary battery that can be manufactured and a method for manufacturing the same.

  Hereinafter, means for solving the problem will be described using the parenthesized symbols used in [DETAILED DESCRIPTION]. These symbols are added to clarify the correspondence between the description of [Claims] and the description of [Mode for Carrying Out the Invention], and are described in [Claims]. It should not be used to interpret the technical scope of the claimed invention.

A non-aqueous electrolyte secondary battery according to the present invention comprises a negative electrode (2) and a positive electrode (1) opposed to the negative electrode (2) at least partially via a porous separator (3) having pores. ). The positive electrode (1) has a facing region (1-3) facing the negative electrode (2) and a non-facing region (1-4) not facing the negative electrode (2). A hole blocking portion (32) in which holes are blocked is formed in the entire region corresponding to the non-opposing region in the separator (3).
According to the present invention, even if a non-opposing region (1-4) is generated due to a shift in the stacking position of the positive electrode (1) and the negative electrode (2), a part of the non-opposing region (1-4) is removed. It is possible to prevent excessive metal ions from being supplied with respect to the electric capacity allowed by the negative electrode.
Furthermore, even if the metal (4) is deposited on the negative electrode (2) due to the non-opposing region, the deposited metal (4) may reach the positive electrode (1) side due to the hole closing portion (32). Is prevented. Therefore, the growth of the metal deposited from the negative electrode or the contact between the metal deposited from the negative electrode and the positive electrode can be prevented.

The positive electrode (1) is a portion where the positive electrode active material layer (1-2) is formed on at least a part of the positive electrode current collector (1-1). The positive electrode current collector (1-1) has a positive electrode tab (11) extending from the facing region (1-3) toward the outside of the facing region (1-1). At this time, the non-facing region (1-4) is formed at the boundary portion with the facing region (1-3) in the positive electrode tab (11), and the positive electrode active material layer (1) is surely formed in the facing region (1-3). -2) is a surplus area (1-5) provided as a margin.
If the positive electrode tab (11) is provided with a portion where the positive electrode active material layer (1-2) is formed as a margin, the positive electrode active material layer (1-2) is surely attached to the opposing region (1-3) during manufacturing. It becomes easy to form. Even if this surplus region (1-5) is not opposed to the negative electrode (2), there is no problem because the growth of the metal (4) is blocked by the hole closing portion (32). That is, the heat generation of the battery can be prevented.

  The facing region (1-3) is preferably rectangular.

  The positive electrode (1) and the negative electrode (2) are preferably sheet-shaped.

The hole closing portion (32) is preferably provided at a position corresponding to the entire circumference of the outer peripheral portion of the positive electrode (1).
According to the present invention, the metal (4) deposited on the negative electrode (2) even when the non-opposing region (1-4) is generated by shifting the stacking position of the positive electrode (1) and the negative electrode (2). ) Can be blocked.

  The separator (3) preferably has a bag shape covering both surfaces of the positive electrode (1) or the negative electrode (2). The separator (3) covers the first sheet (33) covering the main surface side of the positive electrode (1) or the negative electrode (2) and the back surface side of the positive electrode (1) or the negative electrode (2). The first sheet (33) and the second sheet (34) are welded to each other so as to form a bag shape, and the hole blocking part (32) is The first sheet (33) and the second sheet (34) are preferably provided at the welded portion.

The method for producing a nonaqueous electrolyte secondary battery according to the present invention includes a step of forming a positive electrode active material layer (1-2) on a positive electrode current collector (1-1), and a positive electrode active material after the step. A step of producing a positive electrode (1) by cutting into a shape including a layer (1-2), a positive electrode current collector (1-1), and a positive electrode tab (11), and producing a negative electrode (2) A step of forming a hole blocking portion (32) in which holes are blocked in a part of the porous separator (3), and a positive electrode (1) and a negative electrode ( 2) and laminating so as to face each other. The step of creating and manufacturing the positive electrode (5) is a second step in which the first side (41) is located inside the end of the positive electrode planned portion (12) and is the end of the positive electrode planned portion (12). A step of cutting so that the side (42) crosses the positive electrode tab (11). The stacking step is performed so that the excess region (1-5) formed between the first side (41) and the second side (42) in the positive electrode tab (11) faces the hole blocking portion (32). , Including a step of making the positive electrode (2) face the separator (3).
According to this invention, since the positive electrode (1) can be cut and manufactured, it can be produced efficiently. In addition, by cutting the positive electrode current collector (1-1) so that the second side (42) crosses the positive electrode tab planned region (13), even if the cutting position is shifted, it is ensured that A positive electrode active material layer (1-2) can be formed. Here, since the positive electrode active material layer (1-2) is surely formed in the region to be opposed, while the surplus region (1-5) is not opposed to the negative electrode (2), the metal (4) is deposited. It becomes easy to do. However, since the surplus region (1-5) faces the hole blocking portion (32), the metal deposited on the negative electrode (2) can be blocked by the hole blocking portion (32), and the positive electrode An internal short circuit between the electrode (1) and the negative electrode (2) is prevented.

  In the method for manufacturing a non-aqueous electrolyte secondary battery, the facing region (1-3) is preferably rectangular.

  The step of forming the hole blocking portion (32) preferably includes the step of forming the hole blocking portion (32) at a position that is to be opposed to the entire circumference of the outer peripheral portion of the positive electrode (1).

  In addition, the step of forming the hole blocking portion (32) includes the step of disposing the separator (3) on both surfaces of the positive electrode (1) or the negative electrode (2), and the separator (3 And the step of laminating the outer periphery of the positive electrode (1) or the negative electrode (2) having separators (3) disposed on both sides. It is preferable to include a step of laminating with the negative electrode (2) or the positive electrode (1).

  According to the present invention, even if a non-opposing region occurs due to a shift in the stacking position of the positive electrode and the negative electrode, the growth of the metal deposited from the negative electrode or the contact between the metal deposited from the negative electrode and the positive electrode is prevented. A non-aqueous electrolyte secondary battery and a method for manufacturing the same are provided.

It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is explanatory drawing for demonstrating metal precipitation in a non-facing area | region. It is a perspective view which shows an electrode laminated body. It is a perspective view which shows an electrode laminated body. It is a perspective view which shows an electrode laminated body. It is a perspective view which shows an electrode laminated body. It is a top view which shows the positional relationship of a positive electrode and a negative electrode. It is a top view which shows the positional relationship of a positive electrode and a negative electrode. It is a top view which shows the positional relationship of a positive electrode and a negative electrode. It is a top view which shows the positional relationship of a positive electrode and a negative electrode. It is a top view which shows the positional relationship of a positive electrode and a negative electrode. It is explanatory drawing for demonstrating the manufacturing method of a positive electrode. It is explanatory drawing for demonstrating the manufacturing method of a positive electrode. It is explanatory drawing for demonstrating the manufacturing method of a positive electrode. It is a top view which shows the positional relationship of a separator and a positive electrode. It is a top view which shows the positional relationship of a separator and a positive electrode. It is a top view which shows the positional relationship of a separator and a positive electrode. FIG. 6B is a cross-sectional view along AA ′ of FIG. 6A. It is explanatory drawing for demonstrating the bonding part of a separator. It is explanatory drawing for demonstrating the bonding part of a separator. It is explanatory drawing for demonstrating the bonding part of a separator. It is explanatory drawing for demonstrating the bonding part of a separator. It is explanatory drawing for demonstrating the bonding part of a separator. It is explanatory drawing for demonstrating a mode that a metal is interrupted | blocked. It is a graph which shows the relationship between charging time and temperature when charging the nonaqueous electrolyte secondary battery concerning embodiment of this invention. It is a graph which shows the relationship between the charging time and temperature when charging the nonaqueous electrolyte secondary battery for a comparison.

  Embodiments of the present invention will be described below with reference to the drawings. The nonaqueous electrolyte secondary battery according to the present embodiment includes an electrode laminate that is in contact with a nonaqueous electrolyte (not shown). 3A to 3D are perspective views schematically showing an example of the structure of the electrode laminate. The electrode laminate is a structure in which a plurality of positive electrodes 1 and a plurality of negative electrodes 2 are alternately laminated. The negative electrode 2 and the positive electrode 1 are opposed to each other with the separator 3 interposed therebetween. Each of the plurality of positive electrodes 1 is provided with a positive electrode tab 11. Each of the plurality of negative electrodes 2 is provided with a negative electrode tab 21. The positive electrode tab 11 and the negative electrode tab 21 are provided in order to take out the electric power of an electrode laminated body outside. This electrode laminate is obtained by alternately laminating positive electrodes 1 and negative electrodes 2 with separators 3 interposed therebetween.

  4A to 4E are plan views for illustrating the positional relationship between the positive electrode 1 and the negative electrode 2. For convenience of explanation, illustration of the separator 3 in FIGS. 4A to 4E is omitted.

The positive electrode 1 includes a positive electrode current collector 1-1 and a positive electrode active material layer 1-2 formed on at least a part of the positive electrode current collector. Hereinafter, a positive electrode active material layer 1-2 provided in at least a part of the positive electrode current collector 1-1 is defined as a positive electrode 1 hereinafter. As the positive electrode current collector 1-1, for example, an alloy containing these such as aluminum, chromium, molybdenum, nickel, iron, titanium, or stainless steel is used. Examples of the positive electrode active material layer 1-2 include LiCo _x Ni _1-x O ₂ (0 ≦ x ≦ 1), LiNiO ₂ , LiMn _x Ni _y Co _1-xy O _z , and LiCo _x Ni _{y. al 1-x-y O z} , LiFePO 4, LiVPO 4 F, Li x Mn y PO 4, Li x Co y PO 4, Li x Ti y PO 4, LiAlO 2, LiMnO 2, LiMn 2 O 4, MnO 2 , LiCoO ₂ , V ₂ O ₅ , V ₆ O ₁₃ , Li ₃ V ₂ O ₅ , Cr ₂ O ₅ , Cr ₃ O ₈ , LiFeO ₂ , FeF ₃ , FeVO ₄ and other metal oxides, TiS ₂ , MoS ₂ Such metal sulfides, organic sulfur compounds, polyaniline, polypyrrole or substances containing these are used.
The negative electrode 2 includes a negative electrode current collector 2-1 and a negative electrode active material layer 2-2 formed on at least a part of the negative electrode current collector. Hereinafter, the negative electrode active material layer 2-2 provided in at least a part of the negative electrode current collector 2-1 is defined as a negative electrode 2. As the negative electrode current collector 2-1, for example, copper or an alloy containing copper is used. Examples of the negative electrode active material 2-2 include graphite materials, graphitizable carbon, non-graphitizable carbon, carbonaceous materials such as CNT, Nb 2 O 5, Li _x Ti _y O _x , tin composite oxide, SiO _x An oxide such as TiSi, Sn, Si, Li, Cu, Ni, La, Ce, Pr, Nb, Co or an alloy containing these is used.

  The positive electrode 1 has a region facing the negative electrode 2. Hereinafter, a region facing the negative electrode 2 on the positive electrode 1 is referred to as a facing region 1-3.

  The positive electrode current collector 1-1 forms a positive electrode tab 11 extending from one side (first side 41) of the positive electrode 1 toward the outside of the facing region 1-3. The positive electrode tab 11 has a portion where the positive electrode active material layer 1-2 is not formed. However, a positive electrode active material layer 1-2 is formed on the positive electrode tab 11 for convenience of manufacturing. The portion where the positive electrode active material layer 1-2 is formed in the positive electrode tab 11 is hereinafter referred to as an excess region 1-5.

  Similar to the positive electrode 1, also in the negative electrode 2, the negative electrode tab 21 extends from the negative electrode current collector 2-1 toward the outside of the facing region 1-2. However, the negative electrode tab 21 is arranged so that the positive electrode tab 11 and the negative electrode tab 21 do not overlap. Therefore, the positive electrode tab 11 has a region not facing the negative electrode 2. As a result, the surplus region 1-5 has a region that is not opposed to the negative electrode 2 so that the growth of the metal 4 deposited from the negative electrode 2 or the metal deposited from the negative electrode 2 during charging as described above. There is a concern about the contact between 4 and the positive electrode 1.

Here, in order to explain the reason why the surplus region 1-5 is formed, the manufacturing process of the positive electrode 1 will be described with reference to FIGS. 5A to 5C.
In producing the positive electrode 1, first, a positive electrode current collector 1-1 is prepared. And the positive electrode active material layer 1-2 is formed in both surfaces of this positive electrode electrical power collector 1-1. In FIG. 5A to FIG. 5C, the portion where the positive electrode active material layer 1-2 is provided is described as the positive electrode planned portion 12. In addition, a portion where the positive electrode active material layer 1-2 is not provided on the positive electrode current collector 1-1 is described as a scheduled tab portion 13. Further, the boundary between the positive electrode planned portion 12 and the tab planned portion 13 is described as a second side 42.
After forming the positive electrode planned portion 12, the region including the positive tab planned portion 13 and the positive electrode planned portion 12 is cut to obtain the positive electrode 1. Here, the positive electrode active material layer 1-2 does not need to be formed on the positive electrode tab 11. On the contrary, the positive electrode active material layer 1-2 needs to be surely provided in the facing region 1-3. Therefore, when cutting, it is ideal to cut so that the first side 41 of the positive electrode 1 overlaps the second side 42. However, it is difficult to form the positive electrode active material layer 1-2 at exactly the same position on both surfaces of the positive electrode current collector 1-1, and it is also difficult to control the cutting position with high accuracy. Therefore, in consideration of these positional deviation amounts, the first side 41 is slightly (example: 0 to 5 mm) slightly on the side where the positive electrode active material layer 1-2 is provided rather than the end of the positive electrode planned portion 12. Cut so that it is located at. That is, the second side 42 is cut so as to cross the positive electrode tab 11. Thereby, in the formed positive electrode 1, the positive electrode active material layer 1-2 is provided up to a part of the positive electrode tab 11. A region where the positive electrode active material layer 1-2 is formed in the positive electrode tab 11 becomes a surplus region 1-5. That is, the surplus region 1-5 is a region formed as a margin for reliably providing the positive electrode active material layer in the facing region 1-3.

  Similarly to the positive electrode 1, the negative electrode 2 is also produced by forming a negative electrode active material layer 2-2 on the negative electrode current collector 2-1, and then cutting a predetermined region.

  Next, the separator 3 that covers the positive electrode 1 or the negative electrode 2 will be described.

  The separator 3 has a structure that covers the positive electrode 1 or the negative electrode 2 and is provided to prevent contact between the positive electrode 1 and the negative electrode 2. However, metal ions in the non-aqueous electrolyte must be able to pass through the separator 3. Accordingly, a porous separator having fine pores is used as the separator 3. Further, as the separator 3, a material having heat melting property is used. As the material of the separator 3, for example, an organic resin such as polypropylene or polyethylene or a mixture thereof, or a mixture of an inorganic compound such as ceramics in the mixture of the organic resin or the organic tree is used. it can.

  6A to 6C are plan views for explaining the structure of the separator 3, and FIG. 7 is a cross-sectional view taken along AA 'in FIG. 6A. The separator 3 includes a first sheet 33 that covers one side of the positive electrode 1 or the negative electrode 2 and a second sheet 34 that covers the back side of the positive electrode 1 or the negative electrode 2. The entire circumference of the first sheet 33 and the second sheet 34 protrudes from the negative electrode 2. In the portion protruding from the negative electrode 2, the first sheet 33 and the second sheet 34 are welded except for the region overlapping the negative electrode tab 21. The welded portion between the first sheet 33 and the second sheet 34 is a hole blocking portion 32 in which the holes are crushed over the entire area. On the other hand, the part facing the negative electrode 2 is a hole part in which the hole remains as it is.

The hole closing portion 32 is formed when the two sheets (33, 34) are bonded together. Specifically, first, the porous first sheet 33 and the second sheet 34 are disposed on the main surface and the back surface side of the positive electrode 1 or the negative electrode 2. Then, heat is applied to the outer peripheral portions of the first sheet 33 and the second sheet 34. As a result, the first sheet 33 and the second sheet 34 are thermally melted, the holes are closed, and the hole closing portion 32 is formed.
Here, when two sheets are bonded by heat melting, heat is usually applied so that the bonded portions of the two sheets are located intermittently for the purpose of preventing wrinkles. For example, as shown in FIG. 8A to FIG. 8B, the two sheets are pasted together so that the joining portion has a mesh shape. Thereby, a non-adhesion part is partially formed and wrinkle generation by adhesion can be prevented.
On the other hand, in this embodiment, as shown in FIG. 9A, the two sheets are thermally welded so that the bonding portion is the entire area of the outer peripheral portion of the separator. That is, there is no non-bonded part. This is to prevent the metal deposited on the negative electrode 2 from penetrating the separator 3 by adhering the whole area of the outer peripheral portion and closing the holes. In addition, the hole obstruction | occlusion part 32 may be provided in the part facing at least the surplus area | region 1-5, as FIG. 9B-FIG. 9C show.

  Returning to FIGS. 6A and 7, the positional relationship between the separator 3 and the positive electrode 1 will be described. The separator 3 faces the positive electrode 1 at a predetermined position. Here, the positive electrode 1 and the separator 3 face each other so that the surplus region 1-5 overlaps the hole blocking portion 32.

  Subsequently, the operation of the present embodiment will be described with reference to FIG. When charging the nonaqueous electrolyte secondary battery having the above-described configuration, excess metal ions are supplied from the surplus region 1-5 not facing the negative electrode 2, and lithium is deposited on the end of the negative electrode 2. To do. However, since the hole closing portion 32 is provided at a position corresponding to the surplus region 1-5, the deposited metal 4 does not penetrate the separator 3. The metal block 4 can be blocked by the hole closing portion 32, and the growth of the metal deposited from the negative electrode or the contact between the metal deposited from the negative electrode and the positive electrode can be prevented.

  In the present embodiment, the case where the hole closing portion 32 is formed on the entire outer periphery of the separator 3 has been described, but it is not always necessary to be provided on the entire periphery of the outer peripheral portion. It is only necessary to be provided at a position facing one surplus region 1-5. However, if the hole closing portion 32 is provided on the entire outer periphery of the separator 3 as in the present embodiment, the surplus region 1-5 may be caused due to misalignment when the positive electrode 15 and the negative electrode 2 are stacked. Even if the positive electrode 1 protrudes from the negative electrode 2 at other portions, it is possible to prevent the metal 4 from penetrating the separator 3.

  In the present embodiment, the case where the positive electrode 1 and the negative electrode 2 are substantially rectangular has been described. However, the shapes of the positive electrode 1 and the negative electrode 2 are not limited to a rectangular shape, and may be other shapes.

  Further, in the present embodiment, a stacked nonaqueous electrolyte secondary battery in which a plurality of sheet-like positive electrodes and a plurality of sheet-like negative electrodes are alternately stacked has been described. However, the present invention can be applied to a wound non-aqueous electrolyte secondary battery in which a sheet-like positive electrode and a negative electrode are wound together, or a folded non-aqueous battery in which a sheet-like positive electrode and a negative electrode are stacked and further folded. Even when applied to an electrolyte secondary battery, the above-described effects can be obtained.

  Subsequently, in order to more specifically describe the operation of the present embodiment, the experimental results performed by the present inventors will be described. FIG. 11 shows the relationship between the charging time and the battery temperature for the lithium ion battery described in this embodiment. On the other hand, FIG. 12 shows the relationship between charging time and battery temperature for a non-aqueous electrolyte secondary battery prepared for comparison. As the non-aqueous electrolyte secondary battery for comparison, a battery in which the outer peripheral portion of the separator 3 was intermittently heat-welded as shown in FIGS. 8A to 8B was used. About other points, it is the same as that of the nonaqueous electrolyte secondary battery of this embodiment.

As shown in FIG. 12, in the nonaqueous electrolyte secondary battery for comparison, the battery temperature suddenly rises when charging is started. This is presumably because the generation of the metal 4 deposited from the negative electrode 2, the growth of the metal 4 deposited from the negative electrode 2, and the contact between the metal 4 deposited from the negative electrode 2 and the positive electrode 1 occurred. Actually, after the experiment was completed, the comparative nonaqueous electrolyte secondary battery was disassembled and the state of the separator 3 and the negative electrode 2 was observed. As a result, the metal 4 was separated at the position corresponding to the surplus region 1-5 of the positive electrode 1. 3 was confirmed to penetrate.
On the other hand, in the experiment using the nonaqueous electrolyte secondary battery of the present embodiment shown in FIG. 11, the battery temperature did not increase rapidly even when charging was started, and the comparative nonaqueous electrolyte was not used. The temperature rise was suppressed compared to the secondary battery. Further, as in the case of the comparative nonaqueous electrolyte secondary battery, the battery was disassembled after the experiment was completed and the state of the separator 3 and the negative electrode 2 was observed. The metal 4 was separated at the position corresponding to the surplus region 1-5. The effect by having provided the hole obstruction | occlusion part 32 was not confirmed.

DESCRIPTION OF SYMBOLS 1 Positive electrode 1-1 Positive electrode collector 1-2 Positive electrode active material layer 1-3 Opposite area | region 1-4 Non-opposite area | region 1-5 Excess area | region 2 Negative electrode 2-1 Negative electrode collector 2-2 Negative electrode active material layer DESCRIPTION OF SYMBOLS 3 Separator 4 Metal 11 Positive electrode tab 12 Positive electrode electrode scheduled part 13 Tab scheduled part 21 Negative electrode tab 31 Hole part 32 Hole block | closed part 33 1st sheet 34 2nd sheet 41 1st edge 42 2nd edge 51 Positive electrode end and outer periphery Perimeter of part 101 positive electrode 102 negative electrode 103 separator 104 metal

Claims (13)

Nonaqueous in which a positive electrode having a positive electrode active material layer provided on at least a part of a positive electrode current collector and a negative electrode having a negative electrode active material layer provided on at least a part of the negative electrode current collector are alternately laminated In electrolyte secondary batteries,
The positive electrode is at least partially opposed to the negative electrode through a porous separator having pores,
The positive electrode active material layer on the positive electrode current collector includes a facing region facing the negative electrode active material layer on the negative electrode current collector through the separator, and a non-facing region not facing the negative electrode active material layer. Have
A non-aqueous electrolyte secondary battery in which a whole area of a region corresponding to the non-opposing area in the separator is formed with a hole closing portion in which the holes are blocked. The non-aqueous electrolyte secondary battery according to claim 1,
The positive electrode current collector has a positive electrode tab extending toward the outside of the facing region;
At least a part of the positive electrode tab is the facing region;
Non-aqueous electrolyte secondary battery. A non-aqueous electrolyte secondary battery according to claim 1 or claim 2,
The negative electrode is rectangular, and the opposing region is rectangular.
Non-aqueous electrolyte secondary battery. A non-aqueous electrolyte secondary battery according to claim 1 or claim 2 or claim 3,
The positive electrode current collector and the negative electrode current collector are non-aqueous electrolyte secondary batteries having a sheet shape. A non-aqueous electrolyte secondary battery according to claim 1 or claim 2 or claim 3 or claim 4,
The non-aqueous electrolyte secondary battery in which the hole blocking portion is provided at a position corresponding to the entire periphery of the separator facing the outer peripheral portion of the positive electrode. A non-aqueous electrolyte secondary battery according to claim 1 or claim 2 or claim 3 or claim 4 or claim 5,
The separator is a non-aqueous electrolyte secondary battery having a bag shape covering both surfaces of the positive electrode or the negative electrode. A non-aqueous electrolyte secondary battery according to claim 6,
The separator includes a first sheet that covers a main surface side of the positive electrode, and a second sheet that covers a back surface side of the positive electrode,
The first sheet and the second sheet are welded to each other so as to form a bag,
The hole blocking portion is a non-aqueous electrolyte secondary battery provided at a welded portion between the first sheet and the second sheet. A non-aqueous electrolyte secondary battery according to claim 6,
The separator includes a first sheet that covers a main surface side of the negative electrode, and a second sheet that covers a back surface side of the negative electrode,
The first sheet and the second sheet are welded to each other so as to form a bag,
The hole blocking portion is a non-aqueous electrolyte secondary battery provided at a welded portion between the first sheet and the second sheet. Forming a positive electrode active material layer on the positive electrode current collector;
After the step, a step of producing a positive electrode by cutting into a shape including the positive electrode active material layer, the positive electrode current collector, and a positive electrode tab;
Forming a negative electrode active material layer on the negative electrode current collector;
After the step, a step of cutting a shape including the negative electrode active material layer, the negative electrode current collector, and a negative electrode tab to produce a negative electrode;
A step of forming a hole blocking portion in which a hole is blocked in a part of a porous separator;
And alternately stacking the positive electrode and the negative electrode so as to face each other with a separator interposed therebetween,
The step of laminating includes the step of causing the positive electrode to face the separator so that a peripheral portion including an end of the positive electrode active material layer faces the hole blocking portion. Method. A method for manufacturing a nonaqueous electrolyte secondary battery according to claim 9, comprising:
The method for manufacturing a non-aqueous electrolyte secondary battery, wherein the negative electrode is rectangular and the opposing region is rectangular. A method for manufacturing a non-aqueous electrolyte secondary battery according to claim 9 or 10,
The step of forming the hole blocking portion includes a step of forming the hole blocking portion at a position that is scheduled to face the entire outer periphery of the positive electrode. A method for manufacturing a non-aqueous electrolyte secondary battery according to claim 11, comprising:
The step of forming the hole blocking portion includes:
Arranging the separator on both sides of the positive electrode so that the outer peripheral portion protrudes;
Welding the outer periphery of the separator so that the pores are closed over the entire outer periphery,
The step of laminating includes a step of laminating the positive electrode having the separator disposed on both sides with the negative electrode. A method for manufacturing a non-aqueous electrolyte secondary battery according to claim 11, comprising:
The step of forming the hole blocking portion includes:
Arranging the separator on both sides of the negative electrode so that the outer periphery protrudes;
Welding the outer periphery of the separator so that the pores are closed over the entire outer periphery,
The step of laminating includes a step of laminating the negative electrode having the separator disposed on both sides with the positive electrode.

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