JP2007018861A - Separator for battery and battery using this - Google Patents

Separator for battery and battery using this Download PDF

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Publication number
JP2007018861A
JP2007018861A JP2005198856A JP2005198856A JP2007018861A JP 2007018861 A JP2007018861 A JP 2007018861A JP 2005198856 A JP2005198856 A JP 2005198856A JP 2005198856 A JP2005198856 A JP 2005198856A JP 2007018861 A JP2007018861 A JP 2007018861A
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separator
layer
battery
porosity
active material
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JP2005198856A
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Shin Nagayama
Koichi Nemoto
好一 根本
森 長山
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Nissan Motor Co Ltd
日産自動車株式会社
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/60Other road transportation technologies with climate change mitigation effect
    • Y02T10/70Energy storage for electromobility
    • Y02T10/7005Batteries
    • Y02T10/7011Lithium ion battery

Abstract

There is provided a means capable of effectively preventing a short circuit between positive and negative active material layers while enabling a further thinning of a separator.
In the battery separator 1, the porosity of the separator is changed with respect to the thickness direction of the separator, but the porosity of at least one surface with respect to the thickness direction of the separator is the central portion. It is preferably larger than the porosity. When a plurality of separators having different porosity are stacked, the first separator layer 2 having a lower porosity is in the central portion, and the second separator layer 3 having a higher porosity is on at least one surface. Laminated.
[Selection] Figure 5

Description

  The present invention relates to a battery separator. In particular, the present invention relates to an improvement for improving the reliability and output characteristics of a battery separator.

  In recent years, in order to cope with air pollution and global warming, reduction of the amount of carbon dioxide has been strongly desired. In the automobile industry, there is a great expectation for reducing carbon dioxide emissions by introducing electric vehicles (EV) and hybrid electric vehicles (HEV), and the development of secondary batteries for motor drive that holds the key to commercialization of these is thriving. Has been done.

  As a secondary battery for driving a motor, a lithium ion secondary battery having the highest theoretical energy among all the batteries is attracting attention, and is currently being developed rapidly. The lithium ion secondary battery includes, for example, a positive electrode in which a positive electrode active material or the like is applied to both surfaces of a positive electrode current collector using a binder, and a negative electrode in which a negative electrode active material or the like is applied to both surfaces of a negative electrode current collector using a binder. However, it has the structure connected through the electrolyte layer containing electrolyte, and accommodated in a battery case (for example, refer patent document 1). In this case, a separator is generally disposed in the electrolyte layer for the purpose of preventing a short circuit between the positive and negative active material layers. As such a separator, conventionally, a microporous film or a nonwoven fabric made of polyolefin such as polyethylene (PE) or polypropylene (PP) has been used.

For example, a separator is disclosed which is a porous film made of a mixture of PE and PP, and the PE content in the thickness direction of the film is changed (see Patent Document 2). According to the document 2, such a separator is considered to be a porous film suitable for a battery separator because of its high safety, low electrical resistance, high mechanical strength.
JP 2003-7345 A JP 7-216118 A

  By the way, in recent years, there has been a demand for the development of a battery capable of exhibiting a higher output in consideration of the use in automobiles and the like. Under such circumstances, the improvement of the separator is also becoming more important. Specifically, the current situation is that further thinning of the separator is required. The reduction in the thickness of the separator can contribute to the improvement of the output characteristics of the battery through effects such as a reduction in battery volume and a reduction in ion diffusion resistance in the separator.

  In view of such a current situation, when the separator is made thin, if the separator is made of the polyolefin-based material as described above, the PE content in the thickness direction of the separator as described in Reference 2 above. Even if the rate is changed, the ion diffusion resistance is not sufficiently reduced, and the thickness of the separator needs to be extremely thin in order to obtain a sufficient thinning effect.

  However, the original purpose of the separator is, as the name suggests, to separate the positive electrode active material layer and the negative electrode active material layer that face each other via the separator and prevent a short circuit caused by contact between these active material layers. It is in. Therefore, if the separator is too thin, there is a possibility that a short circuit will not be effectively prevented, and the significance of arranging the separator will be lost.

  As described above, for the battery separator, there is a trade-off relationship between the contribution to high output by thinning and the prevention of short circuit by maintaining a constant thickness. Note that the problems described above are significant in bipolar batteries that are being developed to achieve even higher output.

  Therefore, the present invention provides means for satisfying both of the above requirements in a trade-off relationship, that is, means capable of effectively preventing a short circuit between the positive and negative active material layers while enabling further reduction in the thickness of the separator. The purpose is to provide.

  In order to solve the above-mentioned problems, the present inventors diligently searched for the cause that the effect of improving ion diffusion resistance due to thinning cannot be sufficiently obtained in a polyolefin-based material generally used as a constituent material of a separator. did. As a result, it has been found that the polyolefin-based material generally has a low porosity causing the above-mentioned problems. And based on such knowledge, the present inventors tried to control the porosity which a separator has. As a result, it has been found that the above problem can be solved by changing the porosity of the separator with respect to the thickness direction of the separator, and the present invention has been completed.

  That is, this invention is a separator for batteries, Comprising: The porosity which the separator has is changing with respect to the thickness direction of a separator, It is a separator characterized by the above-mentioned.

  In the battery separator of the present invention, the porosity of the separator changes in the thickness direction. As a result, it is possible to achieve both prevention of short circuit by ensuring insulation and improvement of output characteristics by ensuring lithium ion conductivity.

  Embodiments of the present invention will be described below.

  A first aspect of the present invention is a separator for a battery, wherein the porosity of the separator changes with respect to the thickness direction of the separator.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following embodiments. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

(First embodiment)
FIG. 1 is a cross-sectional view showing a battery separator (hereinafter also simply referred to as “separator”) according to a first embodiment.

  The separator 1 of this embodiment shown in FIG. 1 has a configuration in which three separator layers are laminated. Specifically, it is composed of a first separator layer 2 laminated at the center and two second separator layers 3 laminated on both sides of the first separator layer 2. Each of these separator layers (2, 3) has pores 100, but the porosity of the first separator layer 2 is smaller than the porosity of the second separator layer 3. It should be noted that the words “first” and “second” on the separator layers (2, 3) mean that each separator layer (2, 3) has a different porosity. It is merely used for convenience, and there is no particular meaning to the first or second order itself.

  “Porosity” is the percentage of the volume of the pores in the total volume of each separator layer (2, 3).

  As described above, the first separator layer 2 has a lower porosity than the second separator layer 3, but there is no particular limitation on the specific value of the porosity. For example, the porosity of the first separator layer 2 is preferably 20 to 90%, more preferably 30 to 85%, and still more preferably 40 to 80%. If the porosity of the first separator layer is too small, lithium ion diffusion resistance may increase. On the other hand, if the porosity of the first separator layer is too large, there is a possibility that problems such as piercing and a decrease in breaking strength may occur. Moreover, the porosity which the 2nd separator layer 3 has should just be larger than said 1st separator layer 2, and although it does not restrict | limit, Preferably it is 40 to 99%, More preferably, it is 50 to 95%. More preferably, it is 60 to 95%. If the porosity of the second separator layer is too small, the lithium ion diffusion resistance may increase. On the other hand, if the porosity of the second separator layer is too large, the structural strength is small, and there is a possibility that the second separator layer may be crushed during lamination.

  For the measurement of the porosity of each separator layer (2, 3), a method of measuring the basis weight and thickness of the material, a direct observation method using an electron microscope, or a press-fitting method using a mercury porosimeter can be used. When the obtained value can vary, the value obtained by the measurement method of the basis weight and the thickness with respect to the density of the material is adopted as the “porosity” of the present application.

  The thickness of each separator layer (2, 3) is not particularly limited, and conventionally known knowledge can be appropriately referred to in the field of batteries. However, from the viewpoint of increasing the output of the battery, the smaller the thickness of the separator layer, the more preferable as described above. On the other hand, even if the separator layer is too thin, it is preferable from the viewpoint of preventing a short circuit between the positive and negative electrodes. As described above, there is no such thing. From such a viewpoint, the thickness of the first separator layer 2 having a relatively small porosity is about 1 to 25 μm, preferably 3 to 10 μm. On the other hand, the thickness of the second separator layer 3 having a relatively large porosity is about 1 to 25 μm, preferably 3 to 10 μm. The thickness of the entire separator is preferably about 3 to 50 μm, more preferably 5 to 20 μm.

  The material constituting each separator layer (2, 3) is not particularly limited as long as it is an insulating material, and conventionally known knowledge can be appropriately referred to in the field of batteries. For example, the separator layers (2, 3) are made of, for example, polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyimide (PI), polyamide (PA ), Polyamide-imide (PAI), resin-based materials such as cellulose, or insulating ceramics such as silica and alumina. Regarding the shape, in addition to a sheet shape, a material obtained by bonding materials such as a fiber shape, a flake shape, and a particle shape may be used. In addition, the constituent material of the 1st separator layer 2 and the constituent material of the 2nd separator layer 3 may be the same, and may differ.

  The separator 1 of this embodiment can be manufactured without using a special technique. Hereinafter, although an example of the manufacturing method of the separator 1 of this embodiment is demonstrated, it is not restricted only to the following form, Of course, it may be manufactured with another method.

  First, one first separator layer 2 and two second separator layers 3 are prepared.

  About the 1st separator layer 2 and the 2nd separator layer 3, when goods are marketed, what purchased the goods concerned may be used, and what was manufactured by themselves may be used.

  When manufacturing each separator layer (2, 3) by itself, as a method for controlling the porosity of the separator layer, for example, a solvent in the solution and a constituent material of the separator (for example, resin) in casting in the casting method And a method of changing the composition and a method of generating physically fine holes in the separator once completed. However, other methods may be used depending on circumstances.

  Next, both surfaces of the first separator layer 2 prepared as described above are sandwiched by the two second separator layers 3 prepared as described above. Thereby, the separator 1 of this embodiment is completed. In addition, you may perform another process as needed. For example, the thickness and porosity of the separator 1 as a whole may be controlled to a desired value by pressing a laminate of the first separator layer 2 and the two second separator layers 3. When pressing, heating may be performed (so-called hot pressing). Further, when sandwiching, adjacent layers may be bonded using an adhesive or the like as long as the effects of the present invention are not impaired.

  In the separator 1 of this embodiment shown in FIG. 1, the second separator layer 3 having a higher porosity is disposed on both sides of the first separator layer 2 having a lower porosity. The technical scope of the invention is not limited to such a form. For example, one of the two second separator layers 3 as shown in FIG. A separator 1 in which the first separator layer 2 and the second separator layer 3 are stacked one by one can also be included in the scope of the present invention.

  In the above description, the separator of the present invention has been described as being formed by laminating a plurality of separator layers having different porosities. However, in some cases, as shown in FIG. The separator of this invention may be comprised by the separator layer of 1 sheet from which the porosity has changed. A technique similar to that described above can also be adopted as a technique for controlling the porosity in such a separator.

(Second Embodiment)
In 2nd Embodiment, a battery is comprised using the separator 1 of this invention.

  Specifically, the separator 1 of the present invention is used for an electrolyte layer of a battery and exhibits a function of preventing a short circuit between the positive and negative electrodes while holding the electrolyte. There is no restriction | limiting in particular about the specific structure of said battery, It uses in order to comprise the electrolyte layer of arbitrary batteries. In some cases, it may be used to construct the electrolyte layer of a newly developed battery.

  Hereinafter, with reference to the drawings, the present embodiment will be described by taking as an example a case where it is employed in a bipolar lithium ion secondary battery (hereinafter also referred to as “bipolar battery”), which is a kind of nonaqueous electrolyte secondary battery. A mode in which this separator is employed in a battery will be described. However, as described above, the technical scope of the present invention is not limited only to the form adopted for the bipolar battery.

  FIG. 4 is a cross-sectional view showing an outline of a bipolar battery.

  The bipolar battery 10 in the form shown in FIG. 4 has a structure in which a substantially rectangular battery element 21 in which a charge / discharge reaction actually proceeds is sealed inside a laminate sheet 29 that is an exterior.

  The battery element 21 of the bipolar battery 10 having the form shown in FIG. 4 includes a plurality of bipolar electrodes in which the positive electrode active material layer 13 is formed on one surface of the current collector 11 and the negative electrode active material layer 15 is formed on the other surface. Have. Each bipolar electrode is laminated via an electrolyte layer 17 to form a battery element 21. At this time, each bipolar electrode and electrolyte layer are arranged such that the positive electrode active material layer 13 of one bipolar electrode and the negative electrode active material layer 15 of another bipolar electrode adjacent to the one bipolar electrode face each other through the electrolyte layer 17. 17 are stacked. In addition, the electrolyte layer 17 of the bipolar battery 10 of the form shown in FIG. 4 includes the separator 1 of the form (first embodiment) shown in FIG. Moreover, in the bipolar battery 10 of the form shown in FIG. 4, the electrolyte which comprises the electrolyte layer 17 is a liquid electrolyte. That is, the electrolyte layer 17 has a configuration in which a gel electrolyte is injected into the separator 1 of the first embodiment.

  The adjacent positive electrode active material layer 13, electrolyte layer 17, and negative electrode active material layer 15 constitute one unit cell layer 19. FIG. 5 is an enlarged schematic cross-sectional view of a laminate including one single battery layer 19 and two current collectors 11 sandwiching the single battery layer 19 included in the bipolar battery 10 having the configuration shown in FIG. FIG. 5 shows a form in which the current collector 11, the positive electrode active material layer 13, the electrolyte layer 17, the negative electrode active material layer 15, and the current collector 11 are laminated in this order. Therefore, it can be said that the bipolar battery 10 has a configuration in which the single battery layers 19 are stacked. In addition, an insulating layer 31 for insulating adjacent current collectors 11 is provided on the outer periphery of the unit cell layer 19. The current collector (outermost layer current collector) (11a, 11b) located in the outermost layer of the battery element 21 has a positive electrode active material layer 13 (positive electrode side outermost layer current collector 11a) or a negative electrode only on one side. One of the active material layers 15 (negative electrode side outermost layer current collector 11b) is formed.

  Furthermore, in the bipolar battery 10 shown in FIG. 4, the positive electrode side outermost layer current collector 11a is extended to form a positive electrode tab 25, which is led out from a laminate sheet 29 which is an exterior. On the other hand, the negative electrode side outermost layer current collector 11 b is extended to form a negative electrode tab 27, which is similarly derived from the laminate sheet 29.

  Hereinafter, although the member which comprises the bipolar battery 10 of the form shown in FIG. 4 is demonstrated easily, it will not restrict | limit only to the following form and a conventionally well-known form may be employ | adopted similarly.

[Current collector (including outermost layer current collector)]
The current collector 11 and the outermost layer current collector (11a, 11b) are made of a conductive material such as an aluminum foil, a copper foil, or a stainless steel (SUS) foil. The general thickness of the current collector is 1 to 30 μm. However, a current collector having a thickness outside this range may be used.

  The size of the current collector 11 is determined according to the use application of the bipolar battery 10. If a large electrode used for a large battery is manufactured, a current collector having a large area is used. If a small electrode is produced, a current collector with a small area is used.

[Active material layer]
The active material layer contains an active material, and further contains other additives as necessary.

The positive electrode active material layer 13 includes a positive electrode active material. As the positive electrode active material, a lithium-transition metal composite oxide is preferable, and examples thereof include a Li—Mn composite oxide such as LiMn 2 O 4 and a Li—Ni composite oxide such as LiNiO 2 . In some cases, two or more positive electrode active materials may be used in combination.

  The negative electrode active material layer 15 includes a negative electrode active material. As the negative electrode active material, the above lithium transition metal-composite oxide or carbon is preferable. Examples of carbon include graphite-based carbon materials such as natural graphite and artificial graphite, carbon black, activated carbon, carbon fiber, coke, soft carbon, and hard carbon. In some cases, two or more negative electrode active materials may be used in combination.

  Examples of the additive that can be included in the positive electrode active material layer 13 and the negative electrode active material layer 15 include a binder, a conductive additive, a lithium salt (supporting electrolyte), and an ion conductive polymer. When an ion conductive polymer is included, a polymerization initiator for polymerizing the polymer may be included.

  Examples of the binder include polyvinylidene fluoride (PVdF) and a synthetic rubber binder.

  The conductive assistant refers to an additive that is blended in order to improve the conductivity of the positive electrode active material layer 13 or the negative electrode active material layer 15. Examples of the conductive assistant include graphite and vapor grown carbon fiber.

Examples of the lithium salt (supporting salt) include LIBETI (Li (C 2 F 5 SO 2 ) 2 N), LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiCF 3 SO 3 and the like.

  Examples of the ion conductive polymer include polyethylene oxide (PEO) -based and polypropylene oxide (PPO) -based polymers. Here, the ion conductive polymer may be the same as or different from the ion conductive polymer used as the matrix polymer in the electrolyte layer 17 of the bipolar battery 10, but is preferably the same.

  The polymerization initiator is added to act on the crosslinkable group of the ion conductive polymer to advance the crosslinking reaction. The polymerization initiator is classified into a photopolymerization initiator, a thermal polymerization initiator, and the like according to an external factor for causing the polymerization initiator to act. Examples of the polymerization initiator include azobisisobutyronitrile (AIBN), which is a thermal polymerization initiator, and benzyl dimethyl ketal (BDK), which is a photopolymerization initiator.

  The compounding ratio of the components contained in the positive electrode active material layer 13 and the negative electrode active material layer 15 is not particularly limited. The blending ratio can be adjusted by appropriately referring to known knowledge about lithium ion secondary batteries.

[Electrolyte layer]
The electrolyte layer 17 has the separator 1 of the present invention, and the separator 1 includes an electrolyte.

  The electrolyte contained in the electrolyte layer 17 is, for example, a liquid electrolyte. The liquid electrolyte is an electrolytic solution that does not contain a matrix polymer and is obtained by dissolving a lithium salt in a plasticizer. As specific forms of the plasticizer and the lithium salt constituting the liquid electrolyte, the forms exemplified above can be similarly employed.

  In some cases, a solid electrolyte may be used. Solid electrolytes include gel electrolytes and intrinsic polymer electrolytes.

  The gel electrolyte refers to an ion conductive polymer that is a matrix polymer that holds an electrolytic solution. Examples of the ion conductive polymer include polyalkylene oxide polymers exemplified in the column of the active material layer. Lithium salts can be well dissolved in such polymers. In addition, these polymers can exhibit excellent mechanical strength by forming a crosslinked structure. In the present application, the gel electrolyte also includes a polymer skeleton that does not have lithium ion conductivity and a similar electrolyte solution held therein. The kind of electrolyte solution (lithium salt and plasticizer) used is not particularly limited. Examples of the lithium salt include the compounds exemplified in the column of the active material layer. Examples of the plasticizer include carbonates such as propylene carbonate and ethylene carbonate.

  On the other hand, the intrinsic polymer electrolyte is an electrolyte that does not contain a liquid component and is obtained by dissolving a lithium salt in an ion conductive polymer (matrix polymer). As specific forms of the polymer and lithium salt constituting the intrinsic polymer electrolyte, the forms exemplified above can be similarly adopted.

[Insulation layer]
In the bipolar battery 10, an insulating layer 31 is usually provided around each unit cell layer 19. The insulating layer 31 prevents the adjacent current collectors 11 in the battery from coming into contact with each other or a short circuit caused by a slight irregularity at the end of the unit cell layer 19 in the battery element 21. Is provided. The installation of such an insulating layer 31 ensures long-term reliability and safety, and can provide a high-quality bipolar battery 10.

  The insulating layer 31 may be made of a material having insulating properties, sealing properties against falling off of the solid electrolyte, sealing properties against moisture permeation from the outside (sealing properties), heat resistance at the battery operating temperature, and the like. For example, urethane resin, epoxy resin, polyethylene resin, polypropylene resin, polyimide resin, rubber or the like can be used. Among these, urethane resin and epoxy resin are preferably used as the constituent material of the insulating layer 31 from the viewpoints of corrosion resistance, chemical resistance, ease of production (film forming property), economy, and the like.

[tab]
In the bipolar battery 10, the tab (positive electrode tab 25 and negative electrode tab 27) electrically connected to the outermost layer current collector (11a, 11b) is used for taking out the current outside the battery. Take out to the outside. Specifically, a positive electrode tab 25 electrically connected to the positive electrode outermost layer current collector 11a and a negative electrode tab 27 electrically connected to the negative electrode outermost layer current collector 11b are provided outside the exterior. It is taken out.

  The material constituting the tabs (the positive electrode tab 25 and the negative electrode tab 27) is not particularly limited, and a known material conventionally used as a tab for a bipolar battery can be used. Examples of the constituent material of the tab include aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof. Note that the same material may be used for the positive electrode tab 25 and the negative electrode tab 27, or different materials may be used. Further, as shown in FIG. 4, the outermost layer current collector (11a, 11b) may be extended to form tabs (25, 27), or a separately prepared tab may be connected to the outermost layer current collector. Good.

[Exterior]
In the bipolar battery 10, the battery element 21 is preferably housed in an exterior such as a laminate sheet 29 in order to prevent external impact and environmental degradation during use. The exterior is not particularly limited, and a conventionally known exterior can be used. A polymer-metal composite laminate sheet or the like excellent in thermal conductivity can be preferably used in that heat can be efficiently transferred from a heat source of an automobile and the inside of the battery can be rapidly heated to the battery operating temperature.

  As described above, the application example of the separator 1 of the present embodiment has been described by taking the form adopted for the bipolar battery as an example, but the adoption of the separator 1 of the present embodiment prevents the short circuit by securing the insulation in the battery, It is possible to achieve both improvement of output characteristics by ensuring lithium ion conductivity.

  Moreover, the separator 1 of this embodiment can exhibit the outstanding effect, especially when employ | adopted as a bipolar battery. That is, bipolar batteries are being developed on the premise of taking out high output (large current), but when discharging under high output conditions, cations located near the positive electrode active material layer side of the electrolyte layer (for example, Lithium ions) are taken into the positive electrode active material, and the cation concentration at the site decreases rapidly. Along with this, the lithium ion diffusion resistance in the part increases rapidly, causing an increase in the internal resistance of the entire battery. On the other hand, the separator 1 of the present embodiment also functions as a supply source of the cation (lithium ion) because the porosity of the portion adjacent to the positive electrode active material layer (second separator layer 3) is relatively large. In addition, the occurrence of the problems as described above can be effectively suppressed. Further, since a portion having a relatively low porosity (first separator layer 2) is disposed in the central portion, the mechanical strength of the electrolyte layer is also maintained sufficiently large. Note that the above-described problem of ion depletion can also occur in the negative electrode during charging by the same mechanism, but according to the separator 1 of the present embodiment, the occurrence of this problem can be similarly suppressed.

  As described above, the electrolyte layer 17 of the bipolar battery 10 in the form shown in FIG. 4 includes the separator 1 in the form shown in FIG. 1, but in some cases, the separator 1 in the form shown in FIG. The separator 1 having the form shown in each drawing described later can also be employed as a constituent material of the electrolyte layer 17 of a battery such as a bipolar battery. Here, the separator 1 in the form shown in FIG. 2 has a configuration in which two separator layers (2, 3) having different porosities are laminated. When used in a bipolar battery, any separator is used. The layers (2, 3) may be disposed so as to face the positive electrode active material layer or the negative electrode active material layer.

  However, in consideration of the mechanism that exerts the above-described effects, the first separator layer having a low porosity so that the porosity on the negative electrode active material layer 15 side is increased when the charging performance is important. 2 is preferably arranged so as to face the positive electrode active material layer, and the second separator layer 3 having a large porosity faces the negative electrode active material layer. Similarly, when emphasizing the discharge performance, the first separator layer 2 having a low porosity faces the negative electrode active material layer so that the porosity on the positive electrode active material layer 13 side is increased, and the porosity is increased. It is preferable that the second separator layer 3 having a large diameter is disposed so as to face the positive electrode active material layer.

(Production method)
In addition, the manufacturing method of the bipolar battery of the form shown in FIG. 4 is not particularly limited, and conventionally known knowledge can be appropriately referred to in the battery manufacturing field. Hereinafter, one method for manufacturing a bipolar battery will be described by taking the case where the electrolyte layer 17 includes a liquid electrolyte as an example. However, the present invention is not limited to the following embodiments, and other methods may be adopted. Good.

  When manufacturing the bipolar battery 10, first, a positive electrode active material slurry is applied to one surface of the current collector 11 to form a coating film containing the positive electrode active material. On the other hand, the negative electrode active material slurry is applied to the other surface of the current collector 11 to form a coating film containing the negative electrode active material. For the outermost layer current collector, only the positive electrode active material slurry is applied to one surface of the positive electrode side outermost layer current collector 11a, and only the negative electrode active material slurry is applied to one surface of the negative electrode side outermost layer current collector 11b. To do. Then, a coating film is dried by performing a drying process as needed. Specific means for applying the slurry and drying the coating film are not particularly limited, and conventionally known knowledge can be appropriately referred to in the field of battery production.

  For the active material slurry, for example, a desired active material and other components (for example, a binder, a conductive additive, a lithium salt, an ion conductive polymer, a polymerization initiator, etc.) are mixed in a solvent as required. Can be prepared. Since the specific form of each component blended in the active material slurry is as described in the above-mentioned configuration column, detailed description is omitted here. Further, the content of each component contained in the active material slurry is not particularly limited, and can be appropriately adjusted with reference to the description in the above-mentioned configuration column and the conventionally known knowledge about the electrolyte layer of the battery.

  The kind of solvent and the mixing means are not particularly limited, and conventionally known knowledge about electrode production can be appropriately referred to. As an example of the solvent, N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethylacetamide, methylformamide and the like can be used. When adopting polyvinylidene fluoride (PVdF) as a binder, NMP is preferably used as a solvent.

  The specific form of the current collector 11 used in this step is the same as that described in the column of the configuration of the electrode of the present invention, and a detailed description thereof will be omitted here.

  The active material slurry is applied according to a desired arrangement form of the current collector and the active material layer in the manufactured electrode. For example, when the electrode to be manufactured is a bipolar electrode, a coating film containing a positive electrode active material may be formed on one surface of the current collector 11 and a coating film containing a negative electrode active material may be formed on the other surface. . On the other hand, when an electrode that is not a bipolar type is manufactured, a coating film containing either the positive electrode active material or the negative electrode active material is formed on both surfaces of one current collector.

  When a coating film contains a polymerization initiator, the ion conductive polymer in a coating film is bridge | crosslinked by a crosslinkable group by performing a superposition | polymerization process further. The polymerization treatment in the polymerization step is not particularly limited, and conventionally known knowledge may be referred to as appropriate. For example, when the coating film contains a thermal polymerization initiator (AIBN or the like), the coating film is subjected to heat treatment. Moreover, when a coating film contains a photoinitiator (BDK etc.), light, such as an ultraviolet light, is irradiated. In addition, the heat processing for thermal polymerization may be performed simultaneously with said drying process, and may be performed before or after the said drying process. Furthermore, you may perform the polymerization process of the coating film of an active material layer also as a polymerization process for polymerizing the electrolyte layer mentioned later.

  The surface of the coating film formed by applying and drying the active material slurry as described above generally has irregularities. Such irregularities can cause a short circuit between the positive and negative active materials. Therefore, following the above-described operation, the laminated body in which the coating film is formed on the surface of the current collector 11 is subjected to a pressing process using, for example, a press machine, and the surface of the active material layer of the bipolar electrode is flattened. Thereby, a bipolar electrode is completed.

  Specific means and press conditions for the press treatment are not particularly limited, and can be appropriately adjusted in consideration of a desired value of the surface roughness of the surface of the active material layer after the press treatment. Specific examples of the press process include a hot press machine and a calendar roll press machine.

Thereafter, the separator 1 according to the present invention is prepared, and the separator 1 and the plurality of separators 1 and the plurality of the bipolar active material layers 15 are adjacent to each other via the separator 1. Laminate bipolar electrodes. When bipolar electrodes are stacked,
When laminating the bipolar electrode, the outermost layer current collector in which only the active material layer of the positive electrode or the negative electrode is formed on the uppermost surface and the lowermost surface of the laminate so that the surface on which the active material is not formed is exposed. The bodies (11a, 11b) are stacked.

  Further, during the lamination of the bipolar electrodes, an insulating layer 31 is provided between the adjacent current collectors 11 so as to surround the unit cell layer 19 composed of the positive electrode active material layer 13, the electrolyte layer 17 and the negative electrode active material layer 15. Sandwich. After lamination, the edge of the laminated body is hot-pressed to thermally bond the insulating layer 31 to the current collector 11, thereby completing the battery element 21 of the laminated bipolar battery.

  Thereafter, the positive electrode tab 25 and the negative electrode tab 27 are joined to the outermost layer current collector (11a, 11b). The method for joining the outermost layer current collector and the tab is not particularly limited, and a conventionally known welding method or the like can be used. Examples of the welding method include ultrasonic welding and spot welding. Of these, ultrasonic welding is preferably used because joining at low temperatures is possible. In some cases, as described above, the outermost layer current collectors (11a, 11b) may be extended to form tabs (25, 27).

  On the other hand, separately from the production of the battery element 21, an electrolyte solution composition to be included in the separator 1 in the electrolyte layer 17 is prepared. Specifically, a lithium salt is added to a plasticizer and dissolved to obtain an electrolytic solution composition. In addition, when it is desired to employ a gel electrolyte as the electrolyte, an ion conductive polymer is added to the electrolytic solution composition and mixed. At this time, a polymerization initiator (thermal polymerization initiator or photopolymerization initiator) may be added as necessary. The specific form of each component contained in the composition is as described in the section of the above configuration, and thus detailed description thereof is omitted here. Further, the content of each component in the composition is not particularly limited, and can be appropriately adjusted with reference to the description in the column of the above configuration and conventionally known knowledge about the electrolyte layer of the battery.

  Subsequently, the battery element 21 is sealed in the laminate sheet 29 so that the positive electrode tab 25 and the negative electrode tab 27 are led out. Since the preferred form of the laminate sheet 29 is as described above, detailed description thereof is omitted here.

  After the battery element 21 is sealed in the laminate sheet 29, the electrolytic solution composition prepared above is injected into the laminate sheet 29. Thereby, the said electrolyte solution composition osmose | permeates the battery element 21 (specifically, the separator 1 and the active material layer (13, 15)). In some cases, the electrolytic solution composition may be injected before the battery element 21 is sealed in the laminate sheet 29.

  Here, when a polymerization initiator is contained in the electrolyte composition, at any timing after the composition is injected, a polymerization treatment is performed according to the type of the initiator, and the ion conduction contained in the composition is performed. Polymer is polymerized. The timing for performing the polymerization treatment is not particularly limited, and may be immediately after injection of the composition or after sealing of a laminate sheet 29 described later. When the polymerization process is a heat treatment, the process is simple if the process is performed after sealing the laminate sheet 29. Further, when the polymerization process is a light (for example, UV) irradiation process, it is generally necessary to perform the process before the battery element 21 is sealed in the laminate sheet 29.

  Finally, the laminate sheet 29 is sealed. Thereby, the bipolar battery 10 is completed. The laminate sheet 29 can be sealed by, for example, heat sealing, impulse sealing, ultrasonic fusion, high frequency fusion, or the like.

(First modification)
FIG. 6 is a cross-sectional view showing a first modification of the separator of the present invention.

  The separator 1 of this modification shown in FIG. 6 is the same as the separator 1 of the first embodiment in that it has a configuration in which three separator layers are laminated. Specifically, it is composed of a third separator layer 4 laminated at the center and two fourth separator layers 4 laminated on both sides of the third separator layer 4. And the said 3rd separator layer 4 is comprised from the sheet-like material similar to the separator layer (2, 3) of said 1st Embodiment. On the other hand, the fourth separator layer 5 is made of a particulate material. Therefore, the porosity of the third separator layer 4 is smaller than the porosity of the fourth separator layer 5. The term “third” and “fourth” on the separator layers (4, 5) means that the separator layers (4, 5) are made of different materials. It is only used for convenience, and the order itself such as the third and fourth has no special meaning, as in the first embodiment.

  In the present modification, the fourth separator layer 5 is composed of a particulate material, but the material constituting the particulate material is not particularly limited, and the first separator is the same as the third separator layer 4. Constituent materials similar to those of the separator layers (2, 3) of the embodiment can be adopted. The average particle size of the particulate material is not particularly limited, but is usually about 1 to 30 μm, preferably 3 to 20 μm. However, it goes without saying that a particulate material having a particle size outside these ranges may be used. In the present application, the average particle diameter of the particulate material can be measured, for example, by observation using a scanning electron microscope (SEM) or a transmission electron microscope (TEM). Furthermore, as for the particulate material, when a product is commercially available, a product purchased from the product may be used, or a product prepared by itself may be used. Examples of a method for preparing the particulate material by itself include a method such as pulverization of a large particle size product and a method such as firing of a powdery precursor.

  In the separator 1 of this modification shown in FIG. 6, the fourth separator layer 5 having a higher porosity is disposed on both sides of the third separator layer 4 having a lower porosity. The technical scope of the invention is not limited to such a form. For example, one of the two fourth separator layers 5 is omitted, that is, one third separator. The separator 1 formed by laminating the layer 4 and the fourth separator layer 5 can also be included in the scope of the present invention.

  Also according to the first modification described above, the same effects as those of the first embodiment can be obtained. That is, according to this modified example, it is possible to achieve both prevention of short circuit by ensuring insulation in the battery and improvement of output characteristics by ensuring lithium ion conductivity.

(Second modification)
FIG. 7 is a cross-sectional view showing a second modification of the separator of the present invention.

  The separator 1 of this modified example shown in FIG. 7 has a configuration in which the particulate material 7 is filled into the separator body 6 so as to protrude from both sides of the separator body 6. And the separator main body 6 is comprised from the sheet-like material similar to the separator layer (2, 3) of said 1st Embodiment. On the other hand, the particulate material 7 is made of the same material as that constituting the fourth separator layer 5 of Modification 1 described above. In this modified example, since the particulate material 7 protrudes on both sides of the separator body 6, a separator layer having a higher porosity than the separator body 6 is located on both sides of the separator body 6. It can be said that they are doing.

  In this modified example, the average particle diameter of the particulate material 7 is not particularly limited, but is usually about 1 to 30 μm, preferably 5 to 20 μm. However, it goes without saying that a particulate material having a particle size outside these ranges may be used.

  In addition, in the separator 1 of this modification shown in FIG. 6, the particulate material 7 protrudes from both sides of the separator body 6, but the technical scope of the present invention is not limited only to such a form, for example, A form in which the particulate material 7 protrudes from only one side of the separator body 6 can also be included in the scope of the present invention.

  Also according to the second modified example described above, the same effects as those of the first embodiment can be obtained. That is, according to this modified example, it is possible to achieve both prevention of short circuit by ensuring insulation in the battery and improvement of output characteristics by ensuring lithium ion conductivity.

(Third modification)
FIG. 8 is a cross-sectional view showing a third modification of the separator of the present invention.

  The separator 1 of this modification shown in FIG. 8 first has a separator body 6. This separator main body 6 is comprised from the sheet-like material similar to the separator layer (2, 3) of said 1st Embodiment. And the separator 1 of this modification has the structure by which the convex part 8 which consists of the material similar to the separator main body 6 is formed in the surface of the both sides of the said separator main body 6. FIG. In this modified example, since the protrusions 8 are formed on both sides of the separator body 6, a separator layer having a higher porosity than the separator body 6 is located on both sides of the separator body 6. It can be said that they are doing. Note that the constituent material of the separator body 6 and the constituent material of the convex portion 8 may be the same or different, but are preferably the same.

  In the present modified example, the specific form such as the shape and size of the convex portion 8 is not particularly limited, and can be appropriately determined in consideration of the desired battery performance and the possibility of a short circuit. The shape of the convex part seen from the thickness direction of the separator 1 is not particularly limited, such as a circle, an ellipse, a square, a rectangle, a triangle, a hexagon, and an indefinite shape. Further, the convex portions 8 do not need to be scattered, and in some cases, the convex portions 8 protruding linearly may be provided on the surface of the separator body 6.

  Moreover, the width of the convex portion 8 viewed from the thickness direction of the separator 1 is not particularly limited, but is about 1 to 20 μm, and the thickness (height) of the convex portion 8 is about 1 to 20 μm.

  The method for forming the convex portion 8 on the surface of the separator body 6 is not particularly limited. For example, the separator main body 6 can be formed by spraying the constituent material of the convex portion 8 on the surface of the separator main body 6 or by various methods. A method of patterning the convex portion 8 on the surface of the substrate can be used.

  In addition, in the separator 1 of this modified example shown in FIG. 8, the convex portions 8 are formed on the surfaces on both sides of the separator body 6, but the technical scope of the present invention is not limited only to such a form, For example, the form in which the convex part 8 is formed on the surface of only one side of the separator body 6 can also be included in the scope of the present invention.

  Also according to the third modified example described above, the same effects as those of the first embodiment can be obtained. That is, according to this modified example, it is possible to achieve both prevention of short circuit by ensuring insulation in the battery and improvement of output characteristics by ensuring lithium ion conductivity.

(Third embodiment)
In the third embodiment, a plurality of the bipolar batteries of the second embodiment are connected in parallel and / or in series to constitute an assembled battery.

  FIG. 9 is a perspective view showing the assembled battery of the present embodiment.

  As shown in FIG. 9, the assembled battery 40 is configured by connecting a plurality of bipolar batteries described in the second embodiment. Each bipolar battery 10 is connected by connecting the positive electrode tab 25 and the negative electrode tab 27 of each bipolar battery 10 using a bus bar. On one side surface of the assembled battery 40, electrode terminals (42, 43) are provided as electrodes of the entire assembled battery 40.

  The connection method when connecting the plurality of bipolar batteries 10 constituting the assembled battery 40 is not particularly limited, and a conventionally known method can be appropriately employed. For example, a technique using welding such as ultrasonic welding or spot welding, or a technique of fixing using rivets, caulking, or the like can be employed. According to such a connection method, the long-term reliability of the assembled battery 40 can be improved.

  According to the assembled battery 40 of the present embodiment, an assembled battery having excellent reliability and output characteristics can be provided by using the bipolar battery 10 of the second embodiment as an assembled battery.

  The connection of the bipolar batteries 10 constituting the assembled battery 40 may be all connected in parallel, all may be connected in series, or a combination of series connection and parallel connection may be used. Also good.

(Fourth embodiment)
In the fourth embodiment, the bipolar battery 10 of the second embodiment or the assembled battery 40 of the third embodiment is mounted as a motor driving power source to constitute a transportation system. As a transportation system using the bipolar battery 10 or the assembled battery 40 as a motor power source, for example, a complete electric vehicle that does not use gasoline, a hybrid vehicle such as a series hybrid vehicle or a parallel hybrid vehicle, and a fuel cell vehicle, a wheel motor is used. In addition to cars driven by, trains, motorcycles, ships, aircraft and the like.

  For reference, FIG. 10 shows a schematic diagram of an automobile 50 on which the assembled battery 40 is mounted. The assembled battery 40 mounted on the automobile 50 has the characteristics as described above. For this reason, the automobile 50 equipped with the assembled battery 40 is excellent in reliability and output characteristics, and can provide sufficient output even after being used for a long period of time.

  As described above, some preferred embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and various modifications, omissions, and additions can be made by those skilled in the art. . For example, in the above description, a bipolar lithium ion secondary battery (bipolar battery) has been described as an example. However, the technical scope of the battery of the present invention is not limited to a bipolar battery. A non-type lithium ion secondary battery may be used. For reference, FIG. 11 is a cross-sectional view showing an outline of a lithium ion secondary battery 60 that is not bipolar. In the lithium ion secondary battery 60 shown in FIG. 11, the negative electrode active material layer 15 is slightly smaller than the positive electrode active material layer 13, but is not limited to such a form. A negative electrode active material layer 15 that is the same as or slightly larger than the positive electrode active material layer 13 may also be used.

  The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples.

<Example 1>
<Preparation of separator>
A separator having the form shown in FIG. 1 was produced by the following method.

  First, one first polypropylene microporous film (porosity: 35%, thickness: 10 μm) was prepared as a first separator layer. On the other hand, as the second separator layer, two second polypropylene microporous membranes (porosity: 55%, thickness: 5 μm) were prepared.

  Subsequently, the first polypropylene microporous membrane was sandwiched between two second polypropylene microporous membranes to complete the separator of this example.

  The obtained separator was punched into about 75 mm square using a punch, and used as a test separator.

<Preparation of positive electrode>
Lithium manganate (LiMn 2 O 4 ) (average particle size: 1 μm) (85 parts by mass) as a positive electrode active material, acetylene black (10 parts by mass) as a conductive additive, and polyvinylidene fluoride (PVdF) as a binder (5 parts by mass) was mixed, and then an appropriate amount of N-methyl-2-pyrrolidone (NMP) as a slurry viscosity adjusting solvent was added to prepare a positive electrode active material slurry.

  On the other hand, an aluminum foil (thickness: 20 μm) was prepared as a positive electrode current collector. The positive electrode active material slurry prepared above was applied to one surface of the prepared current collector by a doctor blade method to form a coating film. Subsequently, this coating film was dried at 130 ° C. for 10 minutes. Then, the positive electrode which has a 20-micrometer-thick positive electrode active material layer was completed by pressing a 30-micrometer-thick coating film.

  The obtained positive electrode was punched into about 68 mm square using a punch, and a current collecting tab (aluminum lead) connected to a current collecting tab was used as a test positive electrode.

<Production of negative electrode>
Graphite (average particle size: 1 μm) (90 parts by mass) as a negative electrode active material and polyvinylidene fluoride (PVdF) (10 parts by mass) as a binder are mixed, and then N-methyl-2 as a slurry viscosity adjusting solvent. -An appropriate amount of pyrrolidone (NMP) was added to prepare a negative electrode active material slurry.

  On the other hand, a copper foil (thickness: 20 μm) was prepared as a current collector for the negative electrode. The negative electrode active material slurry prepared above was applied to one surface of the prepared current collector by the doctor blade method to form a coating film. Subsequently, this coating film was dried at 130 ° C. for 10 minutes. Then, the negative electrode which has a 20-micrometer-thick negative electrode active material layer was completed by pressing a 30-micrometer-thick coating film.

  The obtained negative electrode was punched out to about 70 mm square using a punch, and a current collecting terminal (nickel lead) connected to a current collecting tab was used as a test negative electrode.

<Production of test cell>
As an electrolytic solution, a solution obtained by dissolving LiPF 6 as a lithium salt in an equal volume mixed solution of ethylene carbonate (EC) and diethyl carbonate (DEC) to a concentration of 1M was prepared. Moreover, the separator produced above was prepared.

  The test positive electrode, the test separator, and the test negative electrode prepared above were laminated in this order so that the active material layers of each electrode faced to obtain a battery element. Thereafter, the battery element is placed in a laminate film so that the current extraction terminals connected to the positive electrode and the negative electrode are exposed to the outside, and then the electrolyte prepared above is injected and further sealed in a vacuum. A test cell was completed.

<Example 2>
A separator having the form shown in FIG. 2 was produced by the following method.

  First, one first polypropylene microporous film (porosity: 35%, thickness: 10 μm) was prepared as a first separator layer. On the other hand, one second polypropylene microporous film (porosity: 55%, thickness: 10 μm) was prepared as the second separator layer.

  Subsequently, these polypropylene microporous membranes were laminated to complete the separator of this example.

  Except that the separator prepared above was laminated so that the first separator layer faced the positive electrode active material layer and the second separator layer faced the negative electrode active material layer, the same procedure as in Example 1 was used. A test cell was prepared.

<Example 3>
A test cell was produced in the same manner as in Example 2 above, except that the first separator layer faced the negative electrode active material layer and the second separator layer faced the positive electrode active material layer. .

<Example 4>
A separator having the form shown in FIG. 6 was produced by the following method.

  First, a polypropylene microporous film (porosity: 35%, thickness: 10 μm) was prepared as a separator body.

  On the other hand, spherical alumina particles (average particle diameter: 5 μm) as a particulate material are added to NMP as a solvent so as to become 10% by mass, and PVdF as a binder is added so as to become 0.5% by mass. Thus, a particulate material slurry was prepared.

  The particulate material slurry similarly prepared above was applied to both surfaces of the separator body prepared above and dried to form a separator layer (fourth separator layer) composed of the particulate material. When the porosity of the fourth separator layer was observed with an electron microscope, it was about 60%, which was larger than the porosity of the separator body.

  A test cell was produced in the same manner as in Example 1 except that the separator produced above was used.

<Comparative Example 1>
A test cell was produced in the same manner as in Example 1 except that a polypropylene microporous membrane (porosity: 35%, thickness: 20 μm) was used alone as a separator.

<Comparative example 2>
A test cell was produced in the same manner as in Example 1 except that a polypropylene microporous membrane (porosity: 45%, thickness: 20 μm) was used alone as a separator.

<Comparative Example 3>
A test cell was produced in the same manner as in Example 1 except that a polypropylene microporous membrane (porosity: 55%, thickness: 20 μm) was used alone as a separator.

<Comparative example 4>
A test cell was produced in the same manner as in Example 1 except that a polypropylene microporous membrane (porosity: 35%, thickness: 10 μm) was used alone as a separator.

<Charge / discharge test>
For each of the above examples and comparative examples, 10 identical test coin cells were produced. Next, a charge / discharge test was performed 10 times at a constant current of 30 mA for each test cell, and cells that did not cause a short circuit were selected. Moreover, about the selected cell, the discharge capacity when charging / discharging with a constant current of 30 mA was measured. Furthermore, the capacity was measured when the battery was charged to 4.2 V with a constant current of 300 mA after being held at a constant potential of 2.5 V, and when discharged at a constant current of 300 mA after being held at a constant potential of 4.2 V. . These results are shown in Table 1 below. It also shows the yield when selecting cells that did not cause a short circuit.

  From the comparison between each example and each comparative example, by employing the separator of the present invention, a battery excellent in both battery performance during charging and discharging can be provided while effectively preventing a short circuit.

It is sectional drawing which shows the separator of 1st Embodiment. It is sectional drawing which shows the modification of the form shown in FIG. It is sectional drawing which shows the other modification of the form shown in FIG. It is sectional drawing which shows the outline | summary of the battery of 2nd Embodiment which is a bipolar battery. It is an expanded section schematic diagram of a layered product which consists of one current cell layer which a bipolar battery of a 2nd embodiment has, and two current collectors which pinch the single cell layer. It is sectional drawing which shows the 1st modification of the separator of this invention. It is sectional drawing which shows the 2nd modification of the separator of this invention. It is sectional drawing which shows the 3rd modification of the separator of this invention. It is a perspective view which shows the assembled battery of 3rd Embodiment. It is the schematic of the motor vehicle of 4th Embodiment carrying the assembled battery of 3rd Embodiment. It is sectional drawing which shows the outline | summary of the lithium ion secondary battery which is not a bipolar type.

Explanation of symbols

1 separator 2 first separator layer,
3 second separator layer,
4 third separator layer,
5 Fourth separator layer,
6 Separator body,
7 particulate material,
8 Convex,
10 Bipolar battery,
11 Current collector,
13 positive electrode active material layer,
15 negative electrode active material layer,
17 electrolyte layer,
19 cell layer,
21 battery elements,
25 positive electrode tab,
27 negative electrode tab,
29 Laminate sheet,
31 insulating layer,
33 positive electrode current collector,
35 negative electrode current collector,
40 battery packs,
50 cars,
60 Lithium ion secondary battery that is not bipolar,
100 holes.

Claims (11)

  1. A battery separator,
    The separator which the porosity which a separator has has changed with respect to the thickness direction of a separator.
  2.   The separator according to claim 1, wherein a porosity of at least one surface side of the separator is larger than a porosity of a central portion of the separator with respect to a thickness direction of the separator.
  3.   A plurality of separator layers having different porosities are stacked. At this time, a first separator layer having a lower porosity is stacked in the center of the separator, and a second separator layer having a higher porosity is formed. The separator according to claim 2, wherein the separator is laminated on at least one surface of the separator.
  4.   A plurality of separator layers having different porosities are laminated. At this time, the separator is composed of a sheet-like material, and a sheet-like separator layer having a larger porosity is laminated at the center of the separator to constitute a particulate material. The separator according to claim 2, wherein a particulate separator layer having a higher porosity is laminated on at least one surface of the separator.
  5.   The separator according to claim 2, wherein the separator body made of a sheet-like material is filled with a particulate material so as to protrude from at least one surface of the separator body.
  6.   The separator according to claim 2, wherein a convex portion is formed on at least one surface of a separator body made of a sheet-like material.
  7. A battery having at least one unit cell layer in which a positive electrode active material layer including a positive electrode active material, an electrolyte layer including a separator including an electrolyte, and a negative electrode active material layer including a negative electrode active material are laminated in this order. And
    The battery whose separator which comprises the said electrolyte layer is a separator of any one of Claims 1-6.
  8.   The battery according to claim 7, which is a nonaqueous electrolyte battery.
  9.   The battery according to claim 7 or 8, which is a bipolar lithium ion secondary battery.
  10.   The assembled battery using the battery of any one of Claims 7-9.
  11.   A transportation vehicle equipped with the battery according to any one of claims 7 to 9, or the assembled battery according to claim 10.
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007280781A (en) * 2006-04-07 2007-10-25 Sony Corp Nonaqueous electrolyte secondary battery
CN102082249A (en) * 2009-11-30 2011-06-01 索尼公司 Membrane and method for manufacturing the same, battery, microporous membrane and method for manufacturing the same
JP2011233354A (en) * 2010-04-27 2011-11-17 Nissan Motor Co Ltd Separator
JP2013054972A (en) * 2011-09-05 2013-03-21 Sony Corp Separator, nonaqueous electrolyte battery, battery pack, electronic apparatus, electric vehicle, electricity storage device, and electric power system
JP2013069582A (en) * 2011-09-22 2013-04-18 Teijin Ltd Separator for nonaqueous secondary battery, and nonaqueous secondary battery
JP2013118057A (en) * 2011-12-01 2013-06-13 Gs Yuasa Corp Separator and nonaqueous electrolyte secondary battery using the same
WO2013128652A1 (en) * 2012-02-28 2013-09-06 エス・イー・アイ株式会社 Liquid holding body for lithium secondary batteries, and lithium secondary battery
JP2013211194A (en) * 2012-03-30 2013-10-10 Tdk Corp Separator for lithium ion secondary battery and lithium ion secondary battery using the same
JP2014127374A (en) * 2012-12-26 2014-07-07 Nippon Soken Inc Secondary battery and battery pack
WO2014147958A1 (en) * 2013-03-19 2014-09-25 ソニー株式会社 Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and power system
WO2015086759A1 (en) * 2013-12-13 2015-06-18 Basf Se Alkali-ion conducting composite membranes for electronic applications
WO2015110333A1 (en) * 2014-01-23 2015-07-30 Basf Se Electrochemical cells comprising alkali-ion conducting composite membranes
US20160118651A1 (en) * 2014-10-23 2016-04-28 Sion Power Corporation Ion-conductive composite for electrochemical cells
US20160276643A1 (en) * 2015-03-18 2016-09-22 Toyota Jidosha Kabushiki Kaisha Non-aqueous electrolyte secondary battery
US9825328B2 (en) 2015-11-24 2017-11-21 Sion Power Corporation Ionically conductive compounds and related uses

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05151951A (en) * 1991-11-26 1993-06-18 Sanyo Electric Co Ltd Battery with nonaqueous electrolytic solution
JPH1074502A (en) * 1996-08-30 1998-03-17 Sony Corp Nonaqueous electrolyte secondary battery
JP2000208122A (en) * 1999-01-12 2000-07-28 Nitto Denko Corp Separator for battery
JP2001351682A (en) * 2000-06-07 2001-12-21 Matsushita Electric Ind Co Ltd Macromolecular solid electrolyte secondary cell and manufacturing method of the same
JP2004220829A (en) * 2003-01-10 2004-08-05 Nissan Motor Co Ltd Bipolar battery
JP2005108454A (en) * 2003-09-26 2005-04-21 Toshiba Corp Nonaqueous electrolyte secondary battery

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05151951A (en) * 1991-11-26 1993-06-18 Sanyo Electric Co Ltd Battery with nonaqueous electrolytic solution
JPH1074502A (en) * 1996-08-30 1998-03-17 Sony Corp Nonaqueous electrolyte secondary battery
JP2000208122A (en) * 1999-01-12 2000-07-28 Nitto Denko Corp Separator for battery
JP2001351682A (en) * 2000-06-07 2001-12-21 Matsushita Electric Ind Co Ltd Macromolecular solid electrolyte secondary cell and manufacturing method of the same
JP2004220829A (en) * 2003-01-10 2004-08-05 Nissan Motor Co Ltd Bipolar battery
JP2005108454A (en) * 2003-09-26 2005-04-21 Toshiba Corp Nonaqueous electrolyte secondary battery

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007280781A (en) * 2006-04-07 2007-10-25 Sony Corp Nonaqueous electrolyte secondary battery
CN102082249B (en) * 2009-11-30 2014-01-29 索尼公司 Membrane and method for manufacturing the same, battery, microporous membrane and method for manufacturing the same
CN102082249A (en) * 2009-11-30 2011-06-01 索尼公司 Membrane and method for manufacturing the same, battery, microporous membrane and method for manufacturing the same
KR101207640B1 (en) 2010-04-27 2012-12-03 닛산 지도우샤 가부시키가이샤 Separator
JP2011233354A (en) * 2010-04-27 2011-11-17 Nissan Motor Co Ltd Separator
JP2013054972A (en) * 2011-09-05 2013-03-21 Sony Corp Separator, nonaqueous electrolyte battery, battery pack, electronic apparatus, electric vehicle, electricity storage device, and electric power system
JP2013069582A (en) * 2011-09-22 2013-04-18 Teijin Ltd Separator for nonaqueous secondary battery, and nonaqueous secondary battery
JP2013118057A (en) * 2011-12-01 2013-06-13 Gs Yuasa Corp Separator and nonaqueous electrolyte secondary battery using the same
US9490462B2 (en) 2011-12-01 2016-11-08 Gs Yuasa International Ltd. Separator and nonaqueous electrolytic secondary battery including the same
EP2822086A4 (en) * 2012-02-28 2015-10-21 Sei Corp Liquid holding body for lithium secondary batteries, and lithium secondary battery
US10230089B2 (en) 2012-02-28 2019-03-12 Sei Corporation Electrolyte holder for lithium secondary battery and lithium secondary battery
JP2013178934A (en) * 2012-02-28 2013-09-09 Sei Kk Liquid holding body for lithium secondary battery and lithium secondary battery
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RU2593596C2 (en) * 2012-02-28 2016-08-10 Сеи Корпорэйшн Retinaculum electrolyte for lithium battery and lithium rechargeable battery
CN104137321A (en) * 2012-02-28 2014-11-05 Sei株式会社 Liquid holding body for lithium secondary batteries, and lithium secondary battery
KR101930984B1 (en) * 2012-02-28 2018-12-19 에스 이 아이 가부시키가이샤 Liquid holding body for lithium secondary batteries, and lithium secondary battery
JP2013211194A (en) * 2012-03-30 2013-10-10 Tdk Corp Separator for lithium ion secondary battery and lithium ion secondary battery using the same
JP2014127374A (en) * 2012-12-26 2014-07-07 Nippon Soken Inc Secondary battery and battery pack
WO2014147958A1 (en) * 2013-03-19 2014-09-25 ソニー株式会社 Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and power system
CN105190941A (en) * 2013-03-19 2015-12-23 索尼公司 Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and power system
CN107749452A (en) * 2013-03-19 2018-03-02 株式会社村田制作所 Battery, separator, battery pack, electronic equipment, electric vehicle and power system
JP2014182962A (en) * 2013-03-19 2014-09-29 Sony Corp Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device and power system
US20160285064A1 (en) * 2013-03-19 2016-09-29 Sony Corporation Separator, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and electric power system
WO2015086759A1 (en) * 2013-12-13 2015-06-18 Basf Se Alkali-ion conducting composite membranes for electronic applications
WO2015110333A1 (en) * 2014-01-23 2015-07-30 Basf Se Electrochemical cells comprising alkali-ion conducting composite membranes
WO2016064949A1 (en) * 2014-10-23 2016-04-28 Sion Power Corporation Ion-conductive composite for electrochemical cells
US20160118651A1 (en) * 2014-10-23 2016-04-28 Sion Power Corporation Ion-conductive composite for electrochemical cells
US20160276643A1 (en) * 2015-03-18 2016-09-22 Toyota Jidosha Kabushiki Kaisha Non-aqueous electrolyte secondary battery
US10581048B2 (en) 2015-03-18 2020-03-03 Toyota Jidosha Kabushiki Kaisha Non-aqueous electrolyte battery having first separator layer with total pore volume larger than second separator layer
US9825328B2 (en) 2015-11-24 2017-11-21 Sion Power Corporation Ionically conductive compounds and related uses
US9947963B2 (en) 2015-11-24 2018-04-17 Sion Power Corporation Ionically conductive compounds and related uses
US10122043B2 (en) 2015-11-24 2018-11-06 Sion Power Corporation Ionically conductive compounds and related uses
US10388987B2 (en) 2015-11-24 2019-08-20 Sion Power Corporation Ionically conductive compounds and related uses

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