JP2021174701A - Battery separator and electrochemical cell - Google Patents

Abstract

To provide a battery separator that can reduce the possibility of breakage and an electrochemical cell that can improve reliability.SOLUTION: A battery separator 1 includes a plate-shaped base material 10 and a resin member 20. The base material 10 has a first surface 10a, and the first surface 10a has a first groove 11 having a bottom portion 11a. The resin member 20 is positioned so as to cover the bottom portion 11a of the first groove 11.SELECTED DRAWING: Figure 1B

Description

The present disclosure relates to battery separators and electrochemical cells.

As a main member constituting a battery such as a lithium ion battery, there is a separator that separates a positive electrode and a negative electrode and allows a substance such as lithium ion to permeate.

The lithium ion battery described in Patent Document 1 includes a solid electrolyte layer having an average porosity of 9% or less as a separator. In Patent Document 1, the thickness of the solid electrolyte layer is, for example, 1 μm or more and 1000 μm or less, and preferably 10 μm or more and 500 μm or less from the viewpoint of reliability and crack suppression.

International Publication No. 2018/12347

The required performance for the battery is high energy density, and it is possible to realize miniaturization and thinning. In a separator made of a solid electrolyte as described in Patent Document 1, by reducing the thickness, ionic conductivity can be increased, and miniaturization and thinning can be realized, but cracks are likely to occur, and not only during the manufacturing process. , May be damaged during transportation or use.

The battery separator of the present disclosure has a first surface, and has a plate-shaped base material containing lithium ion conductive ceramics and a plate-shaped base material.
With a resin member,
The base material has a first groove having a bottom on the first surface.
The resin member covers the bottom portion.

The electrochemical cell of the present disclosure includes the above-mentioned battery separator and
The negative electrode located on the first surface side and
A positive electrode located on the side opposite to the first surface when viewed from the base material,
The battery separator, the positive electrode, and the package containing the negative electrode are provided.

According to the battery separator of the present disclosure, the possibility of breakage can be reduced. The electrochemical cell provided with the battery separator of the present disclosure can improve reliability.

It is a top view of the battery separator of 1st Embodiment. It is sectional drawing in the cut plane line IB-IB of FIG. 1A. It is a top view of the battery separator of the 2nd Embodiment. It is sectional drawing in the cut plane line IIB-IIB of FIG. 2A. It is a top view of the battery separator of the 3rd Embodiment. It is sectional drawing in the cut plane line IIIB-IIIB of FIG. 3A. It is a bottom view of the battery separator of the 4th embodiment. It is sectional drawing in the cut plane line IVB-IVB of FIG. 4A. It is an enlarged cross-sectional view around the 1st groove of a base material. It is an enlarged cross-sectional view around the 1st groove of a base material. It is an external view of an electrochemical cell. It is sectional drawing in the cut plane line VIII-VIII of FIG. It is an enlarged sectional view of a power generation element.

Hereinafter, the battery separator according to the embodiment of the present disclosure will be described in detail. The battery separator of the present disclosure is used, for example, in a lithium ion battery which is a secondary battery, but is not limited to this, and may be used in a primary battery. It can be used in either a liquid form to be used, a semi-solid form to be used in a gel form or a slurry form using a polymer or the like.

The battery separator 1 of the first embodiment will be described. FIG. 1A is a plan view of the battery separator of the first embodiment. FIG. 1B is a cross-sectional view taken along the cutting plane line IB-IB of FIG. 1A. The battery separator 1 of the present embodiment includes a plate-shaped base material 10 and a resin member 20. The base material 10 has a first surface 10a, and the first surface 10a has a first groove 11 having a bottom portion 11a. The resin member 20 is positioned so as to cover the bottom portion 11a of the first groove 11.

The base material 10 is a plate-shaped member containing lithium ion conductive ceramics. The lithium ion conductive ceramics constituting the base material 10 may be, for example, a dense material. The dense material has, for example, a density of 90% or more. The density can be measured based on the open porosity determined by the vacuum method according to JIS R1634: 1998. For example, the value obtained by subtracting the open porosity from 100% may be used as the density. The base material 10 of this embodiment has a rectangular plate shape. The base material 10 is not limited to a rectangular plate shape, but may be a polygonal shape such as a triangular shape or a pentagonal shape, a disk shape, or an indeterminate shape depending on the battery used. The dimensions of the base material 10 are appropriately set according to the battery used. When the base material 10 is used, for example, as a separator for a lithium ion battery, the dimensions of the base material 10 are, for example, 10 cm in length × 10 cm in width and 20 μm in thickness.

A first groove 11 is provided on the first surface 10a of the base material 10. The first groove 11 may be provided one or more. The plurality of first grooves 11 may be provided in parallel with each other. The cross-sectional shape of the first groove 11 that is perpendicular to the direction in which the groove extends may be a polygonal shape such as a rectangular shape, a trapezoidal shape, or a triangular shape, and may be a semicircular shape or a semi-elliptical shape. The cross-sectional shape of the first groove 11 of the present embodiment is, for example, as shown in FIG. 1B, a trapezoidal shape in which the opening width (upper bottom) is larger than the width (lower bottom) of the bottom portion 11a. The dimensions of the first groove 11 are appropriately set according to the dimensions of the base material 10. When the base material 10 is used, for example, as a separator for a lithium ion battery as described above, the dimensions of the first groove 11 are, for example, a depth of 5 μm, a bottom width of 15 μm, an opening width of 20 μm, and a groove pitch. As an example, it is 5 mm.

The lithium ion conductive ceramics constituting the base material 10 can be used as long as they are ceramic materials used for various batteries such as known lithium ion batteries. As the ceramic material, at least one selected from the group of garnet-based ceramic material, nitride-based ceramic material, perovskite-based ceramic material, phosphoric acid-based ceramic material, and zeolite-based material can be used. Examples of the garnet-based ceramic material include a Li-La-Zr-O material (specifically, Li ₇ La ₃ Zr ₂ O _{12 and the} like) and a Li-La-Nb-O material (specifically, Li ₅ La _3). Nb ₂ O _{12 and the} like), Li-La-Zr-Ga-O materials (specifically, Li _6.25 La ₃ Zr ₂ Ga _0.25 O _{12 and the} like). As the nitride-based ceramic _material, Li 3 _N, (specifically, LixPOyNz (2 ≦ x ≦ 4,3 ≦ y ≦ 5,0.1 ≦ z ≦ 0.9)) LiPON , and the like. Examples of the perovskite-based ceramic material include a Li-La-Ti-O material (specifically, LiLa _1-x Ti _x O ₃ (0.04 ≦ x ≦ 0.14)). Examples of the phosphoric acid-based ceramic material include Li-Al-Ti-P-O material (specifically, Li (Al, Ti) ₂ (PO ₄ ) ₃ ) and Li-Al-Ge-PO material (specifically). Specifically, Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) _3, etc.), and Li-Al-Ti-Si-PO material (specifically, Li _{1 + x + y} Al). _{Examples thereof include x} Ti _2-x Si _y P _3-y O ₁₂ (0 ≦ x ≦ 0.4, 0 <y ≦ 0.6) and the like). _Other, it is also possible to use a composite material such as _{Li 4 SiO 4 -Li 3 PO 4} , Li 4 SiO 4 -Li 3 VO 4. Of these materials, a garnet-based ceramic material or a garnet-type similar ceramic material containing Li, La, Zr, and O is preferable because it has excellent sinterability, is easily densified, and has high ionic conductivity. ..

The resin member 20 is positioned so as to cover the bottom portion 11a of the first groove 11. Since the resin member 20 covers the bottom portion 11a of the first groove 11, it extends in a band shape or a rod shape along the first groove 11. The resin member 20 may cover the entire bottom portion 11a of the first groove 11 in the width direction, or may cover a part of the bottom portion 11a. When the resin member 20 covers a part of the bottom portion 11a, it may cover only the central portion in the width direction or only both ends in the width direction. The thickness of the resin member 20 may be constant or different in the width direction as long as it is positioned so as to cover the bottom portion 11a of the first groove 11. For example, the central portion in the width direction of the resin member 20 may be thin and both ends in the width direction may be thick. The thickness of the resin member 20 (or the average thickness when the thickness is not constant) is 20 μm as an example when the bottom portion 11a is used as a reference.

The resin member 20 is made of a known resin material used in a battery separator. Examples of the resin material include polyolefin or a modified product thereof, PVDF (polyvinylidene fluoride resin), silicon rubber, fluororubber, heat-resistant rubber, aromatic polyamide resin, liquid crystal polyester resin, and heat-resistant resin containing polyoxyalkylene. Examples thereof include nylon, PTFE (polytetrafluoroethylene), polyphenylene ether resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, heat-resistant acrylic resin, and crosslinkable polymer. Among these materials, polyolefin, a modified product thereof, and PVDF (polyvinylidene fluoride resin) are preferable because of their high stability.

By making the base material 10 thinner, the battery separator 1 can be made smaller and thinner, and by increasing the ionic conductivity, a battery having a high energy density can be realized. On the other hand, the thin base material 10 has a problem that it is easily broken. In the battery separator 1 of the present disclosure, by providing the first groove 11 in the base material 10, when a force is applied to the base material 10, stress is concentrated on the bottom portion 11a of the first groove 11, and the base material 10 It reduces the occurrence and extension of cracks in uncertain regions other than the first groove 11. By covering the bottom portion 11a where stress is concentrated with the resin member 20, it is possible to suppress the occurrence of cracks starting from the bottom portion 11a of the first groove 11. Even when a crack occurs starting from the bottom portion 11a of the first groove 11, the resin member 20 suppresses the extension of the crack and also suppresses the movement of substances through the crack. As a result, the possibility of damage to the battery separator 1 can be reduced. In addition, the electrochemical cell provided with the battery separator of the present disclosure can improve reliability.

Further, the base material 10 may have a third groove 13 intersecting the first groove 11 on the first surface 10a. The third groove 13 may be provided one or more. The plurality of third grooves 13 may be provided in parallel with each other. The angle at which the first groove 11 and the third groove 13 intersect is appropriately set according to the dimensions of the base material 10 and the like. The angle at which the first groove 11 and the third groove 13 intersect may be, for example, 15 °, 30 °, 45 °, 60 °, 90 °, or the like. In the present embodiment, the angle at which the first groove 11 and the third groove 13 intersect is 90 °. The cross-sectional shape and dimensions of the third groove 13 may be the same as or different from that of the first groove 11 as long as they are within the same range as the first groove 11. The resin member 20 is also provided in the third groove 13, and has the same effect as that of the first groove 11. When a force is applied to the base material 10 from a plurality of directions, stress is concentrated on the first groove 11 and the third groove 13 intersecting the first groove 11, except for the first groove 11 and the third groove 13 of the base material 10. Reduces cracking and extension in uncertain areas.

In the present embodiment, the first surface 10a of the base material 10 has a rectangular shape, and at least one of the first groove 11 and the third groove 13 is parallel to any one of the sides of the first surface 10a. Extends to. In the present embodiment, the first groove 11 extends parallel to the long side of the first surface 10a, and the third groove 13 extends parallel to the short side of the first surface 10a.

The battery separator 1A of the second embodiment will be described. FIG. 2A is a plan view of the battery separator of the second embodiment. FIG. 2B is a cross-sectional view taken along the cutting plane line IIB-IIB of FIG. 2A. The battery separator 1A of the present embodiment includes a base material 10 and a resin member 20A. In the present embodiment, the resin member 20A is different from the resin member 20 of the first embodiment, and the other configurations are the same. Therefore, the same reference numerals as those of the first embodiment are added and the description thereof will be omitted. The resin member 20A of the present embodiment is positioned so as to cover the inner side surface 11b in addition to the bottom portion 11a of the first groove 11.

The resin member 20A may be provided, for example, along the bottom portion 11a and the inner side surface 11b of the first groove 11. In this case, the resin member 20A has a recess in the opening of the first groove 11. Further, as shown in FIG. 2B, the resin member 20A may be filled in the entire first groove 11, for example. In this case, the surface of the resin member 20A is flush with the first surface 10a of the base material 10. By covering the inner side surface 11b of the first groove 11 with the resin member 20A, it is possible to suppress the occurrence of cracks starting from the inner side surface 11b. Even when a crack occurs starting from the inner side surface 11b of the first groove 11, the resin member 20A suppresses the extension of the crack and also suppresses the movement of substances through the crack. As a result, the possibility of damage to the battery separator 1 can be reduced. In addition, the electrochemical cell provided with the battery separator of the present disclosure can improve reliability. The resin member 20A is also provided in the third groove 13, and has the same effect as that of the first groove 11.

The battery separator 1B of the third embodiment will be described. FIG. 3A is a plan view of the battery separator of the third embodiment. FIG. 3B is a cross-sectional view taken along the cutting plane line IIIB-IIIB of FIG. 3A. The battery separator 1B of the present embodiment includes a base material 10 and a resin member 20B. In the present embodiment, the resin member 20B is different from the resin member 20 of the first embodiment, and the other configurations are the same. Therefore, the same reference numerals as those of the first embodiment are added and the description thereof will be omitted. The resin member 20B of the present embodiment has a first portion 21 filled in the first groove 11 and a second portion 22 connected to the first portion 21 and covering the edge portion 11c of the first groove 11. The edge portion 11c of the first groove 11 is a portion where the inner side surface 11b and the first surface 10a intersect. The edge portion 11c of the first groove 11 is a portion where stress is likely to be concentrated together with the bottom portion 11a. Similar to the resin member 20A of the second embodiment, the first portion 21 of the resin member 20B covers the bottom portion 11a and the inner side surface 11b of the first groove 11, so that the cracks originating from the bottom portion 11a and the inner side surface 11b can be formed. Occurrence can be suppressed. Since the second portion 22 of the resin member 20B covers the edge portion 11c of the first groove 11, the occurrence of cracks starting from the edge portion 11c can be suppressed. The resin member 20B is also provided in the third groove 13, and has the same effect as that of the first groove 11.

The width of the second portion 22 of the resin member 20B covering the edge portion 11c of the first groove 11 is not limited as long as the width at which the decrease in ionic conductivity due to the covering does not pose a practical problem. It is 30 μm in the width direction from the ridgeline where the side surface 11b and the first surface 10a intersect.

The battery separator 1C of the fourth embodiment will be described. FIG. 4A is a bottom view of the battery separator of the fourth embodiment. FIG. 4B is a cross-sectional view taken along the line IVB-IVB of FIG. 4A. The battery separator 1C of the present embodiment includes a base material 10A and a resin member 20. In this embodiment, the base material 10A is different from the base material 10 of the first embodiment, and the other configurations are the same. Therefore, the same reference numerals as those of the first embodiment are added and the description thereof will be omitted. The base material 10A has a second groove 12 on the second surface 10b opposite to the first surface 10a. The second groove 12 may be provided one or more. The plurality of second grooves 12 may be provided in parallel with each other. The cross-sectional shape and dimensions of the second groove 12 may be the same as or different from that of the first groove 11 as long as they are within the same range as the first groove 11. The resin member 20 is also provided in the second groove 12, and has the same effect as that of the first groove 11. Further, by having grooves on both the first surface 10a and the second surface 10b, the battery separator 1C can be easily bent, and the possibility of damage to the battery separator 1 due to an external force can be reduced. For example, in the case of only the first groove 11, cracks are likely to occur in a portion other than the first groove 11 when a bending stress that compresses the first surface 10a side is applied, but the second groove 12 is also provided. Therefore, the occurrence of cracks can be suppressed.

The positional relationship between the first groove 11 and the second groove 12 when viewed in the direction perpendicular to the first surface 10a may be deviated or may overlap. In the present embodiment, as shown in FIG. 4B, the first groove 11 and the second groove 12 overlap when viewed in a direction perpendicular to the first surface 10a. Since the first groove 11 and the second groove 12 overlap each other, the portion of the base material 10A between the two grooves becomes thin, and even if the depths of the first groove 11 and the second groove 12 are shallow, both of them. It is possible to suppress the occurrence of cracks in parts other than the groove. As a result, the same effect can be obtained even if the depths of the first groove 11 and the second groove 12 with respect to the thickness of the base material 10A are made shallower than in the case of only the first groove 11, so that the base material 10A is even thinner. Can be used.

Further, the base material 10A may have a fourth groove 14 intersecting the second groove 12 on the second surface 10b. The fourth groove 14 may be provided one or more. The plurality of fourth grooves 14 may be provided in parallel with each other. The angle at which the second groove 12 and the fourth groove 14 intersect is appropriately set according to the dimensions of the base material 10A and the like. The angle at which the second groove 12 and the fourth groove 14 intersect may be, for example, 15 °, 30 °, 45 °, 60 °, 90 °, or the like. In the present embodiment, the angle at which the second groove 12 and the fourth groove 14 intersect is 90 °. The cross-sectional shape and dimensions of the fourth groove 14 may be the same as or different from that of the first groove 11 as long as they are within the same range as the first groove 11. The resin member 20 is also provided in the fourth groove 14, and has the same effect as that of the second groove 12. When a force is applied to the base material 10A from a plurality of directions, stress is concentrated on the second groove 12 and the fourth groove 14 intersecting the second groove 12, except for the second groove 12 and the fourth groove 14 of the base material 10A. Reduces cracking and extension in uncertain areas.

In the present embodiment, the second surface 10b of the base material 10A has the same rectangular shape as the first surface 10a, and at least one of the second groove 12 and the fourth groove 14 is one of the sides of the second surface 10b. It extends parallel to any one side. In the present embodiment, the second groove 12 extends parallel to the long side of the second surface 10b, and the fourth groove 14 extends parallel to the short side of the second surface 10b.

FIG. 5 is an enlarged cross-sectional view of the periphery of the first groove of the base material. The base material 10 includes a crack 15 extending in a direction perpendicular to the first surface 10a from the bottom portion 11a of the first groove 11. The crack 15 may reach, for example, the second surface 10b of the base material 10. Since the base material 10 contains the crack 15, the battery separator 1 is deformed by the elastic force of the resin member 20 when an external force is applied, so that the flexibility of the battery separator 1 as a whole becomes high, and electrochemical. In the cell, the adhesion to the facing surface of the negative electrode or the positive electrode is improved. The crack 15 may be intentionally generated by applying an external force to the base material 10 at the time of manufacturing, or may be unintentionally generated at the time of manufacturing, transportation, or use of an electrochemical cell.

FIG. 6 is an enlarged cross-sectional view of the periphery of the first groove of the base material. The base material 10 may be filled with a part 23 of the resin member 20 in the crack 15. The contact area between the resin member 20 and the base material 10 increases, and the resin member 20 and the base material 10 are less likely to peel off. As a result, the possibility of damage to the battery separator 1 can be reduced. A part 23 of the resin member 20 may be filled in the crack 15 intentionally generated in the base material 10, and the resin member 20 is melted by the heat generated when the electrochemical cell is used, and the resin member 20 is unintentionally generated. A part 23 that has flowed into the crack 15 may be cured and filled.

The crack 15 can be generated by, for example, a known ceramic substrate dividing step. By using each groove such as the first groove 11 of the base material 10 as a dividing groove (splitting groove) and using a known substrate dividing device, a crack 15 can be generated in the base material 10. In the first to third embodiments, the crack 15 may be generated only in the first groove 11, may be generated only in the third groove 13, and may be generated in both the first groove 11 and the third groove 13. You may let me. In the fourth embodiment, the crack 15 may be generated only between the first groove 11 and the second groove 12, or may be generated only between the third groove 13 and the fourth groove 14. It may be generated between the first groove 11 and the second groove 12 and between the third groove 13 and the fourth groove 14.

The electrochemical cell provided with the above battery separator will be described. FIG. 7 is an external view of the electrochemical cell. FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. Hereinafter, an example in which the electrochemical cell 100 includes the battery separator 1C of the fourth embodiment will be described. As the battery separator included in the electrochemical cell 100, the battery separators 1, 1A and 1B of the first to third embodiments may be used instead of the battery separator 1 of the fourth embodiment. The electrochemical cell 100 is, for example, a semi-solid lithium-ion battery. The electrochemical cell 100 includes a power generation element 102, a package 103, and a terminal 104. The electrochemical cell 100 has, for example, a plate shape. The electrochemical cell 100 functions as a power source for the external device by being electrically connected to the external device.

The power generation element 102 is a member for storing and releasing electricity by utilizing an electrochemical reaction. The power generation element 102 includes, for example, a positive electrode 102a, a negative electrode 102b, and a battery separator 1C between the positive electrode 102a and the negative electrode 102b. The power generation element 102 can transmit cations or anions between the positive electrode 102a and the negative electrode 102b through the battery separator 1C.

The power generation element 102 is, for example, a stack of a positive electrode 102a, a battery separator 1C, and a negative electrode 102b. The power generation element 102 has, for example, a plate shape. In the power generation element 102, for example, a positive electrode 102a, a battery separator 1C, and a negative electrode 102b are laminated in the plate-like thickness direction.

The positive electrode 102a and the negative electrode 102b are, for example, electrochemically active substances. The positive electrode 102a and the negative electrode 102b may have, for example, an active material and an electrolyte. As the electrolyte, for example, a solvent or a solvent mixture to which a salt is added can be used.

The positive electrode 102a is, for example, as a positive electrode active material, nickel cobalt aluminum-based lithium composite oxide (NCA), spinel-based lithium manganate (LMO), lithium iron phosphate (LFP), lithium cobalt oxide (LCO), nickel cobalt manganese. It may contain a lithium composite oxide (NCM) or the like. The positive electrode 102a may contain a solid compound known to those skilled in the art, which is used in, for example, a nickel hydrogen battery, a nickel cadmium battery, and the like. The positive electrode 102a may contain, for example, Mg-doped LiCoO ₂ , LiNiO _{2, and the} like.

The negative electrode 102b may contain, for example, a carbon-based material such as graphite, hard carbon, soft carbon, carbon nanotubes, and graphene as the negative electrode active material. The negative electrode 102b may contain, for example, a titanium-based oxide such as lithium titanate or titanium dioxide. The negative electrode 102b may contain, for example, a transition metal compound containing iron, cobalt, copper, manganese, nickel and the like.

Examples of the positive electrode 102a and the negative electrode 102b include the US provisional patent application Nos. 61 / 787, 382 entitled "Semi-Solid Electrolyte Having High Late Capability" and "Asymmetry Battery Having energy Anode". The active substances and electrolytes described in US Provisional Patent Application No. 61 / 787,372, entitled. The positive electrode 102a and the negative electrode 102b may have additives, for example.

The battery separator 1C allows cations or anions to pass between the positive electrode 102a and the negative electrode 102b. Further, since the power generation element 102 has the battery separator 1C, the positive electrode 102a and the negative electrode 102b can be electrically insulated from each other.

In the case of a plate shape, the power generation element 102 can be set to, for example, 50 to 500 mm in length, 50 to 300 mm in width, and 0.1 to 2.0 mm in thickness.

The packaging body 103 is a member having a space for wrapping the power generation element 102 inside the packaging body. The package 103 is provided to protect the power generation element 102 from the external environment. More specifically, the package 103 is provided to electrically insulate the power generation element 102 from the external environment. The package 103 is provided so as to cover the entire power generation element 102.

Further, the package 103 has, for example, a flat bag shape. The package 103 is formed, for example, by forming a laminated film into a flat bag shape. Further, the package 103 may be formed by welding two laminated films, for example. The package 103 may have a rectangular shape when viewed from the stacking direction of, for example, the positive electrode 102a, the battery separator 1, and the negative electrode 102b.

The package 103 has, for example, an insulating material. As a result, the package 103 can protect the power generation element 102 from the external environment without short-circuiting the external environment and the power generation element 102 via the package 103. The package 103 has, for example, a resin material. More specifically, as the resin material, for example, polyethylene terephthalate, polyethylene, or the like can be used.

Further, the package 103 may have, for example, a multi-layer structure. Specifically, the package 103 has, for example, a heat-adhesive resin material and a heat-resistant resin material. Specifically, the heat-adhesive resin material is a resin material whose melting temperature is lower than 150 ° C. Further, the heat-resistant resin material is specifically a resin material having a melting temperature of 150 ° C. or higher and 300 ° C. or lower. As the heat-resistant resin material, for example, polyethylene terephthalate, polyethylene naphthalate, or the like can be used. As the heat-adhesive resin material, for example, polyethylene, polypropylene, or the like can be used.

The terminal 104 is provided to electrically connect the power generation element 102 and the external device. The terminal 104 is, for example, plate-shaped or strip-shaped. Specifically, the terminal 104 has a rectangular shape when viewed from the stacking direction of the power generation elements 102, for example. The terminal 104 may have a rectangular shape, for example.

When viewed from the stacking direction of the power generation element 102, the terminal 104 is in contact with the power generation element 102. When viewed from the stacking direction of the power generation element 102, the terminal 104 is located on any side of the outer circumference of the power generation element 102. Further, the terminal 104 extends outward from the package 103 because it is electrically connected to the external device. Further, the terminal 104 is electrically connected to the external connection terminal outside the package 103.

The terminal 104 is, for example, a conductive member. The terminal 104 may have, for example, a metal material. More specifically, as the metal material, for example, aluminum, copper, or the like can be used. When the terminal 104 has a plate shape, it can be set to, for example, 30 to 100 mm in length, 10 to 100 mm in width, and 0.1 to 0.5 mm in thickness.

As described above, the battery separator of each embodiment has a reduced possibility of breakage, and the electrochemical cell including the separator can improve the reliability. Further, the electrochemical cell provided with the battery separator of the third embodiment can further improve the reliability. FIG. 9 shows an enlarged cross-sectional view of the power generation element of the electrochemical cell provided with the battery separator 1B of the third embodiment. In the battery separator 1B, the resin member 20B has a second portion 22 that covers the edge portion 11c of the first groove 11, and the second portion 22 protrudes from the first surface 10a of the base material 10. Become a department. In the power generation element 102, the convex portion, which is the second portion 22, is in contact with the negative electrode 102b. The convex portion serves as a partition to block the movement of metal ions (for example, lithium ions) of the negative electrode 102b between the battery separator 1B and the negative electrode 102b. As a result, the generation of dendrites can be suppressed, and the possibility that the positive electrode 102a and the negative electrode 102b are short-circuited can be reduced.

In the battery separator of the present disclosure, each element of the battery separator of each of the above-described embodiments can be appropriately combined. For example, the resin member provided in the first groove 11 may be the resin member 20A of the second embodiment, and the resin member provided in the second groove 12 may be the resin member 20B of the third embodiment. In this case, the battery separator may be provided in the electrochemical cell so that the second surface 10b of the base material 10A faces the negative electrode 102b. Further, for example, the resin member provided in the first groove 11 may be the resin member 20 of the first embodiment, and the resin member provided in the third groove 13 may be the resin member 20A of the second embodiment.

1,1A, 1B, 1C Battery separator 10,10A Base material 10a 1st surface 10b 2nd surface 11 1st groove 11a Bottom 11b Inner surface 11c Edge 12 2nd groove 13 3rd groove 14 4th groove 15 Crack 20 , 20A, 20B Resin member 21 1st part 22 2nd part 23 Part of resin member 100 Electrochemical cell 102 Power generation element 102a Positive electrode 102b Negative electrode 103 Package 104 Terminal

Claims (14)

A plate-shaped base material having a first surface and containing lithium ion conductive ceramics,
With a resin member,
The base material has a first groove having a bottom on the first surface.
The resin member is a battery separator that covers the bottom portion. The first groove further has an inner surface and
The battery separator according to claim 1, wherein the resin member covers the inner side surface. The first groove further has an edge where the inner surface and the first surface intersect.
The battery separator according to claim 1 or 2, wherein the resin member has a first portion filled in the first groove and a second portion connected to the first portion and covers the edge portion. .. The base material has a second surface opposite to the first surface and has a second surface.
The battery separator according to any one of claims 1 to 3, wherein the base material has a second groove on the second surface. The battery separator according to claim 4, wherein the first groove and the second groove overlap when viewed in a direction perpendicular to the first surface. The battery separator according to any one of claims 1 to 5, wherein the base material has a third groove intersecting the first groove on the first surface. The first surface has a rectangular shape and has a rectangular shape.
The battery separator according to claim 6, wherein at least one of the first groove and the third groove extends in parallel with any one of the sides of the first surface. The battery separator according to claim 4 or 5, wherein the base material has a fourth groove intersecting with the second groove on the second surface. The second surface has a rectangular shape and has a rectangular shape.
The battery separator according to claim 8, wherein at least one of the second groove and the fourth groove extends in parallel with any one of the sides of the second surface. The battery separator according to any one of claims 1 to 9, wherein the base material contains a crack extending from the bottom portion in a direction perpendicular to the first surface. The battery separator according to claim 10, wherein the resin member is filled in the crack. The battery separator according to any one of claims 1 to 8, wherein the lithium ion conductive ceramics have a density of 90% or more. The battery separator according to any one of claims 1 to 12,
The negative electrode located on the first surface side and
A positive electrode located on the side opposite to the first surface when viewed from the base material,
An electrochemical cell comprising the battery separator, a package containing the positive electrode and the negative electrode. The resin member has a convex portion protruding from the first surface, and has a convex portion.
The electrochemical cell according to claim 13, wherein the convex portion is in contact with the negative electrode.

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