JP2017204350A - Lithium air battery and negative electrode structure of lithium air battery - Google Patents

Abstract

A lithium-air battery capable of repeatedly using a lithium-air battery by removing sludge when the negative electrode is deactivated by sludge generated during charging and discharging of a lithium-air battery, and restoring the negative electrode without touching air. This negative electrode structure is provided. A lithium-air battery includes a negative electrode, a positive electrode disposed at a distance from the negative electrode, a solid electrolyte disposed between the negative electrode and the positive electrode, and a first charged between the solid electrolyte and the positive electrode. An electrolyte is provided in the battery case. The negative electrode has a negative electrode current collector and a lithium negative electrode body electrically connected to the negative electrode current collector. The lithium-air battery includes a negative electrode, a solid electrolyte disposed with a gap with respect to the lithium negative electrode body, and capable of conducting lithium ions between the lithium negative electrode body and the first electrolyte, and between the lithium negative electrode body and the solid electrolyte. A negative electrode case is provided that houses a second electrolyte capable of conducting lithium ions. The negative electrode case is configured to be detachable from the battery case. [Selection] Figure 3

Description

  The present disclosure relates to a lithium air battery including a positive electrode, a negative electrode, and an aqueous electrolyte, and a negative electrode structure of the lithium air battery.

  In recent years, air batteries having a much higher energy density than lithium ion batteries have been expected for a wide variety of applications such as power storage and electric vehicle applications. The air battery uses oxygen in the air as a positive electrode active material. As such an air battery, a lithium-air battery using a lithium metal, a lithium-based alloy, or a lithium-based compound as a negative electrode active material is known. Such a lithium-air battery is composed of a negative electrode, an electrolyte, and a positive electrode (air electrode), and an aqueous electrolyte or a non-aqueous electrolyte is used as the electrolyte.

  Among these, the lithium-air battery of an aqueous electrolyte generally has a solid electrolyte disposed between the negative electrode and the positive electrode, and a first electrolyte (aqueous electrolyte) is filled between the solid electrolyte and the positive electrode. The second electrolyte (buffer layer) is arranged between the solid electrolyte and the solid electrolyte (see Patent Document 1). Compared with a non-aqueous electrolyte lithium-air battery, such an aqueous electrolyte lithium-air battery is advantageous in that it is not affected by moisture in the air, the electrolyte is inexpensive, and is nonflammable.

  This lithium-air battery is a mechanism for obtaining electricity by reacting lithium ions and oxygen at the positive electrode to generate LiOH (discharge). Further, the generated LiOH can be redischarged by decomposing (charging) Li and oxygen.

Japanese Patent Laying-Open No. 2015-106486 JP-A-2006-9533

  In the lithium-air battery of the aqueous electrolyte described in Patent Document 1, lithium dentite (sludge) may be generated on the negative electrode surface or at least one of the second electrolyte during charging. When this sludge is generated, the amount of metallic lithium regenerated at the negative electrode during charging decreases, and the battery capacity may be reduced.

  On the other hand, Patent Document 2 discloses a metal-air battery in which the electrode can be replaced. When sludge is formed on the negative electrode of a lithium-air battery, the negative electrode is replaced in accordance with Patent Document 2. If this is done, it is considered that the lithium-air battery can be regenerated. However, lithium is highly reactive with air and may burn, and replacement of a negative electrode containing lithium is not easy.

  At least one embodiment of the present invention is an invention based on such a state of the art, and its object is to deactivate the negative electrode by sludge generated during charging and discharging of a lithium air battery. In this case, it is an object to provide a lithium air battery and a negative electrode structure of a lithium air battery in which sludge is removed and the negative electrode is revived without being exposed to air so that the lithium air battery can be used repeatedly.

  (1) A lithium-air battery according to at least one embodiment of the present invention includes a negative electrode, a positive electrode disposed at a distance from the negative electrode, and a solid disposed between the negative electrode and the positive electrode. A lithium-air battery in which an electrolyte and a first electrolyte filled between the solid electrolyte and the positive electrode are provided in a battery case, wherein the negative electrode includes a negative electrode current collector serving as an electrode, and the negative electrode A lithium negative electrode body electrically connected to a current collector, and disposed between the negative electrode and the lithium negative electrode body with a gap between the lithium negative electrode body and the first electrolyte. A negative electrode case that houses the solid electrolyte capable of conducting lithium ions and a second electrolyte capable of conducting lithium ions between the lithium negative electrode body and the solid electrolyte, wherein the negative electrode case is The above And it is configured to be inserted and removed with respect to insertion and removal hole formed on the upper surface of the pond case.

  According to the lithium-air battery described in (1) above, when sludge is generated in the negative electrode or the second electrolyte and the negative electrode is deactivated, the negative electrode case containing the deactivated negative electrode is removed from the battery case. A new negative electrode case is inserted into the battery case. Here, since the negative electrode part case integrally accommodates the negative electrode, the lithium negative electrode body, the solid electrolyte, and the second electrolyte, the lithium negative electrode body does not come into contact with air when the negative electrode part case is inserted or removed. In addition, when the negative electrode is deactivated, a new negative electrode case is inserted into the battery case, so that in the lithium-air battery, no sludge adheres to the negative electrode, and no sludge floats in the second electrolyte. Can be restored. Therefore, when the negative electrode is deactivated by sludge generated during charging / discharging of the lithium-air battery, the sludge is removed and the negative electrode is reactivated without touching the air, so that the lithium-air battery can be used repeatedly. An air battery can be realized.

  (2) In some embodiments, in the lithium-air battery according to (1), the negative electrode case is formed in a box shape, and a first opening is formed on one side surface of the negative electrode case. The first opening is disposed opposite to the positive electrode, and the solid electrolyte is fixed inside the negative electrode case so as to cover the first opening.

  According to the embodiment described in (2) above, since the solid electrolyte covers the first opening and is fixed inside the negative electrode case, there is a possibility that the solid electrolyte protrudes outside the first opening. No. For this reason, when inserting / removing a negative electrode part case with respect to the insertion / removal hole part formed in the upper surface of a battery case, a possibility that a solid electrolyte may contact and damage a insertion / removal hole part can be prevented.

  (3) In some embodiments, in the lithium-air battery according to (2), a plurality of partition members for partitioning the first opening into a plurality of opening portions are mutually connected to the first opening. It extends in the intersecting direction.

  According to the embodiment described in (3) above, since the plurality of partition members are extended in the direction in which the first openings intersect each other, the plurality of partition members form the first openings into the plurality of openings. Can be partitioned. For this reason, the area of the opening portion becomes smaller than the area of the first opening portion, and it is possible to suppress the possibility that an obstacle may come into contact with the opening portion or an external force may act on the opening portion when the negative electrode case is inserted and removed. This can further prevent the solid electrolyte from being damaged.

  (4) In some embodiments, in the lithium-air battery according to (2) or (3), the negative electrode current collector is fixed in a state of being in contact with the plate-like lithium negative electrode body. A current collector main body, and a plurality of connecting portions protruding from at least two different positions on the outer periphery of the current collector main body and connected to the inner surface of the negative electrode case, and the lithium negative electrode body Is configured to be fixed to the negative electrode case through the negative electrode current collector.

  According to the embodiment described in (4) above, the current collector main body is fixed in contact with the plate-like lithium negative electrode body, so that the electrode effect of the current collector main body on the lithium negative electrode body can be reduced. It can be exhibited effectively. In addition, since the plurality of connecting portions protruding from at least two different positions on the outer peripheral portion of the current collector main body of the negative electrode current collector are connected to the inner surface of the negative electrode case, the negative electrode current collector is connected to the negative electrode portion. It can be more firmly fixed to the case. For this reason, a lithium negative electrode body can be more firmly fixed with respect to a negative electrode part case via the collector main-body part fixed in the state which overlapped and contacted the plate-shaped lithium negative electrode body.

  (5) In some embodiments, in the lithium-air battery according to (4), one of the plurality of connection portions protrudes upward from the upper portion of the current collector main body. The negative electrode case is inserted into an insertion hole formed in the upper surface of the negative electrode case and fixed to the negative electrode case, and the other one of the plurality of connection parts is formed below the current collector body. Projecting toward the bottom, connected to the bottom of the negative electrode case, and fixed to the negative electrode case.

  According to the embodiment described in the above (5), by inserting the connection portion protruding upward from the upper portion of the current collector main body portion into the insertion hole portion formed in the upper surface of the negative electrode case, The current collector body can be positioned with respect to the negative electrode case. In addition, the current collector main body positioned with respect to the negative electrode case can be connected to the bottom of the negative electrode case by connecting a connecting portion protruding downward from the lower part of the current collector main body to the negative electrode case. Can be fixed to. Therefore, the current collector body can be fixed in a state of being positioned in the negative electrode case.

  (6) In some embodiments, in the lithium-air battery according to (1), the insertion / removal is performed in the battery case below the insertion / removal hole formed in the upper surface of the battery case. A guide guide is provided for guiding the movement of the negative electrode case when the negative electrode case is inserted into and removed from the battery case through the hole.

  According to the embodiment described in (6) above, since the guide guide for guiding the movement of the negative electrode case is provided in the battery case below the insertion / removal hole, the insertion / removal part is interposed. The insertion / removal operation of the negative electrode case can be facilitated when the negative electrode case is inserted into / removed from the battery case.

  (7) In some embodiments, in the lithium-air battery according to (2), the negative electrode on the side opposite to the side facing the positive electrode in a state where the negative electrode case is inserted into the battery case. The first electrolyte exists between the opposite side surface of the battery case and the inner surface of the battery case, and a second opening is formed on the opposite side surface of the negative electrode case to cover the second opening. The solid electrolyte is fixed inside the negative electrode case, and the second electrolyte is filled between the solid electrolyte and the lithium negative electrode body.

  According to the embodiment described in the above (7), the first electrolyte exists between the opposite side surface of the negative electrode case and the inner surface of the battery case, and the second opening is formed on the opposite side surface. A solid electrolyte covering the second opening is fixed inside the case, and the second electrolyte is filled between the solid electrolyte and the lithium negative electrode body. For this reason, the lithium negative electrode body can move lithium ions on both the surface facing the positive electrode side and the opposite surface. Therefore, the charge / discharge characteristics of the lithium air battery can be improved.

  (8) A negative-electrode structure of a lithium-air battery according to at least one embodiment of the present invention includes a negative electrode, a positive electrode disposed with a gap with respect to the negative electrode, and the negative electrode and the positive electrode. A negative electrode structure in which the disposed solid electrolyte and the first electrolyte filled between the solid electrolyte and the positive electrode can be inserted into and removed from a lithium-air battery provided in a battery case, The negative electrode is composed of a negative electrode current collector to be an electrode and a lithium negative electrode body electrically connected to the negative electrode current collector, and is arranged with a gap with respect to the negative electrode and the lithium negative electrode body A solid electrolyte capable of conducting lithium ions between the lithium negative electrode body and the first electrolyte, and a second electrolyte capable of conducting lithium ions between the lithium negative electrode body and the solid electrolyte. Negative electrode housing Comprising a scan, the negative electrode unit case is configured to be inserted and removed with respect to the battery case of the lithium-air battery.

  According to the negative-electrode structure of the lithium-air battery described in (8) above, the negative-electrode structure of the lithium-air battery includes a negative electrode case in which the negative electrode, the lithium negative electrode body, the solid electrolyte, and the second electrolyte are integrated and accommodated. The negative electrode case can be inserted into and removed from the battery case of the lithium-air battery. For this reason, a lithium negative electrode body does not touch air at the time of insertion / extraction of the negative electrode part case with respect to a battery case. In addition, when the negative electrode is deactivated, a new negative electrode case is inserted into the battery case, so that in the lithium-air battery, no sludge adheres to the negative electrode, and no sludge floats in the second electrolyte. Can be restored. Therefore, when the negative electrode is deactivated by sludge generated during charging / discharging of the lithium-air battery, the sludge is removed and the negative electrode is reactivated without touching the air, so that the lithium-air battery can be used repeatedly. A negative electrode structure of an air battery can be realized.

  According to at least one embodiment of the present invention, when a lithium dent light is formed and a lithium metal negative electrode is deactivated by repeated charging and discharging of the lithium air battery, the lithium metal negative electrode is revived to repeat the lithium air battery. A lithium-air battery that can be used and a negative-electrode structure of the lithium-air battery can be provided.

It is a perspective view of the lithium air battery concerning one Embodiment of this invention. It is a schematic internal structure figure of a lithium air battery. It is sectional drawing of the lithium air battery of the part corresponded to the II arrow of FIG. It is a front side perspective view of a negative electrode part case. It is a schematic internal structure figure of a negative electrode part case. It is sectional drawing of the negative electrode part case of the part corresponded to the VI-VI arrow of FIG. It is sectional drawing of the negative electrode part case corresponded to the III-III arrow of FIG. It is a back side perspective view of the negative electrode part case which concerns on other embodiment. It is sectional drawing of the negative electrode part case which concerns on other embodiment.

  Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, material properties, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Only. For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained. For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state. For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed. On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements. In the following description, the same components may be denoted by the same reference numerals and detailed description thereof may be omitted.

  FIG. 1 is a perspective view of a lithium-air battery according to an embodiment of the present invention. FIG. 2 is a schematic internal structure diagram of the lithium-air battery. FIG. 3 is a cross-sectional view of a portion of the lithium-air battery corresponding to the view taken along arrows II in FIG. FIG. 4 is a front perspective view of the negative electrode case. FIG. 5 is a schematic internal structure diagram of the negative electrode case. FIG. 6 is a cross-sectional view of the negative electrode case in a portion corresponding to the VI-VI arrow in FIG. In addition, the lithium air battery of this embodiment is demonstrated as an example of the lithium air battery provided with a pair of positive electrode and negative electrode.

  As shown in FIGS. 1 and 3, the lithium-air battery 1 according to one embodiment of the present invention is disposed between a negative electrode case 10 including a negative electrode 11, a positive electrode 40, and the negative electrode 11 and the positive electrode 40. The solid electrolyte 50 (see FIG. 6) and the first electrolyte 53 filled between the solid electrolyte 50 and the positive electrode 40 are provided in the battery case 60.

  In the illustrated embodiment, the battery case 60 is formed in a box shape (cuboid shape) having a hollow inside, and a plurality of holes 61 a through which air can flow are provided on one side surface 61 of the battery case 60. ing. In addition, a positive hole 62 a for projecting the upper end of the positive electrode 40 is provided at a central portion on one side of the upper surface 62 of the battery case 60. Further, on the other side of the upper surface 62 of the battery case 60, a negative electrode hole 62 b is provided for the upper end portion of the negative electrode case 10 including the negative electrode 11 to protrude. The positive electrode hole 62 a is formed in a circular shape in plan view, and the negative electrode hole 62 b is formed in a rectangular shape in plan view and extends along the other side end of the upper surface 62 of the battery case 60.

  As shown in FIGS. 2 and 3, the positive electrode 40 includes a positive electrode current collector 41, a positive electrode terminal 42, a water repellent layer 43, and a catalyst 44. In the illustrated embodiment, the positive electrode current collector 41 is formed in a plate shape from, for example, porous carbon, and is disposed opposite to the negative electrode case 10 side. A catalyst 44 is attached to the positive electrode current collector 41. The catalyst 44 has a function of promoting an oxygen reduction reaction during discharging of the lithium air battery 1 and an oxygen oxidation reaction during charging. The positive electrode terminal 42 is formed of a conductive material and is connected to the positive electrode current collector 41. The positive electrode terminal 42 is inserted through the positive electrode hole 62 a and protrudes upward from the upper surface 62 of the battery case 60. When the battery case 60 is made of metal, the negative electrode 11 and the positive electrode 40 may be short-circuited via the battery case 60. Therefore, an insulating member 72 is disposed between the positive electrode 40 and the battery case 60 to prevent a short circuit. Examples of the insulating member 72 include butyl rubber and fluorine rubber.

  The water repellent layer 43 is for preventing the moisture of the first electrolyte 53 from leaking outside through the hole 61 a of the battery case 60. The water repellent layer 43 is formed in a plate shape and is fixed inside the battery case 60 so as to cover the plurality of holes 61a from the inside of the battery case 60 so as to face the plurality of holes 61a.

  The first electrolyte 53 is filled in the battery case 60, is in contact with at least the solid electrolyte 50 (see FIG. 6) and the positive electrode 40, and carries lithium ions between the positive electrode 40 and the solid electrolyte 50. In the illustrated embodiment, the first electrolyte 53 exists between the positive electrode 40 and the negative electrode case 10 and between the back side of the negative electrode case 10 and the inner surface of the battery case 60, as shown in FIG. 3.

The first electrolyte 53 is an aqueous electrolyte in which a lithium salt is dissolved in water. Examples of the first electrolyte 53 include LiCl (lithium chloride), LiOH (lithium hydroxide), LiNO ₃ (lithium nitrate), and CH ₃ CO ₂ Li as lithium salts dissolved in water.

  In some embodiments, as shown in FIGS. 5 and 6, the negative electrode 11 includes a negative electrode current collector 12 and a lithium negative electrode body 15 electrically connected to the negative electrode current collector 12. Yes. The lithium negative electrode body 15 is electrically connected to a part of the negative electrode current collector 12. In the illustrated embodiment, the lithium negative electrode body 15 is formed in a plate shape.

  The lithium negative electrode body 15 is made of, for example, metallic lithium. The lithium negative electrode body is not limited to metallic lithium, and may be an alloy containing lithium as a main component or a compound containing lithium as a main component instead of metallic lithium. Examples of the alloy containing lithium as a main component include magnesium, calcium, aluminum, silicon, germanium, tin, lead, antimony, bismuth, silver, gold, and zinc. Moreover, as a compound which has lithium as a main component, cobalt, copper, nickel etc. are mentioned, for example. In addition, the thickness and area of the lithium negative electrode body are changed according to the battery capacity.

  The negative electrode current collector 12 is formed from at least two different positions of the current collector main body 12a that is fixed in contact with the plate-like lithium negative electrode 15 and the outer periphery of the current collector main body 12a. And a plurality of connection portions 12b that protrude and are connected to the inner surface of the negative electrode case 10. In the illustrated embodiment, the current collector main body 12a may be present stably in the operating range of the lithium-air battery 1, does not alloy with lithium, and has a desired conductivity. For example, it consists of a plate-like or foil-like conductor made of copper, nickel or the like. The lithium negative electrode 15 is fixed in contact with one surface of the current collector body 12a.

  The connection part 12b includes a first connection part 12b1 projecting upward from the upper part of the current collector body part 12a, and a second connection part 12b2 projecting downward from the lower part of the current collector body part 12a. The connection portion 12b has conductivity and is integrally connected to the current collector main body portion 12a. In the illustrated embodiment, the first connection portion 12b1 is connected to the upper center of the current collector main body portion 12a formed in a square shape in a side view and extends upward. A negative electrode terminal 13 serving as an electrode is connected to the upper end of the first connection portion 12b1. The negative terminal 13 protrudes upward from the upper surface 10 a of the negative electrode case 10. The second connection portion 12b2 is connected to the lower center of the current collector main body portion 12a formed in a square shape in a side view and extends downward.

  The negative electrode 11 (the negative electrode current collector 12 and the lithium negative electrode body 15) configured as described above is accommodated in the negative electrode case 10. As shown in FIGS. 4 and 5, the negative electrode case 10 is formed in a box shape, and a first opening 17 is provided on a side surface 10 b on one side of the negative electrode case 10, and the negative electrode case 10 is formed inside the negative electrode case 10. A space 19 that can accommodate the negative electrode 11 is formed.

  In the illustrated embodiment, the first opening 17 opens in a square shape in a side view. A plurality of partition members 21 for partitioning the first opening 17 into a plurality of opening portions 17 a are extended in the first opening 17 so as to face each other. In the illustrated embodiment, the plurality of partition members 21 are extended so as to form a square-shaped opening portion 17a in a side view when facing either the vertical direction or the horizontal direction.

  The upper surface 10a of the negative electrode case 10 is provided with an insertion hole 22 through which the first connection portion 12b1 and the negative electrode terminal 13 are inserted. In the illustrated embodiment, the insertion hole portion 22 opens in a circular shape, and when the negative electrode portion case 10 is viewed from the direction facing the first opening portion 17 of the negative electrode portion case 10, the upper surface 10 a of the negative electrode portion case 10. Is provided at the center in the width direction. The first connection portion 12 b 1 and the negative electrode terminal 13 are inserted into the insertion hole portion 22, and the upper portion of the current collector main body portion 12 a is fixed to the negative electrode portion case 10. The lower end portion of the second connection portion 12b2 protruding from the lower portion of the current collector body portion 12a is connected to the bottom surface of the negative electrode portion case 10, and the lower portion of the current collector body portion 12a is fixed to the negative electrode portion case 10. The first connection portion 12b1 is formed in an elongated shape so as to be inserted through the insertion hole portion 22 and extend from the insertion hole portion 22, and the upper end side of the first connection portion 12b1 becomes the negative electrode terminal 13. It may be configured.

  As described above, the first connection portion 12b1 protruding from the upper portion of the current collector main body portion 12a is inserted into the insertion hole portion 22 formed in the upper surface 10a of the negative electrode portion case 10 to thereby collect the current with respect to the negative electrode case 10. The electric body main body 12a can be positioned. Further, the current collector body 12a positioned with respect to the negative electrode case 10 is connected to the bottom of the negative electrode case 10 by connecting the second connection part 12b2 projecting from the lower part of the current collector body 12a. It can be fixed to the negative electrode case 10. Therefore, the current collector main body 12 a can be fixed in a state of being positioned in the negative electrode case 10.

  As shown in FIG. 6, the solid electrolyte 50 is disposed with a gap 25 with respect to the lithium negative electrode body 15, and conducts lithium ions between the lithium negative electrode body 15 and the first electrolyte 53 (see FIG. 3). Is possible. In the illustrated embodiment, the solid electrolyte 50 is fixed inside the negative electrode case 10 so as to face the first opening 17 and cover the first opening 17. For this reason, the solid electrolyte 50 is disposed inside the negative electrode case 10 with respect to the first opening 17.

The solid electrolyte 50 is made of a material having lithium ion conductivity and no water permeability, and is formed in a plate shape or a film shape. The solid electrolyte 50 is disposed opposite to the lithium negative electrode body 15 of the negative electrode 11 with a gap 25 to protect the lithium negative electrode body 15 from the moisture of the first electrolyte 53 and pass only lithium ions (Li ⁺ ). It is configured to be possible. As the solid electrolyte 50, glass ceramics having water resistance and lithium ion conductivity can be used. The solid electrolyte 50 can be, for example, a NASICON (Na Superconducting Conductor) type lithium ion conductor.

  A second electrolyte 29 capable of conducting lithium ions is accommodated in the negative electrode case 10 between the lithium negative electrode body 15 and the solid electrolyte 50. The second electrolyte 29 is an organic electrolytic solution such as ethylene carbonate in which a lithium salt is dissolved. The second electrolyte 29 may be a solid electrolyte in which a lithium salt is dispersed in a polymer, or may be a gel electrolyte in which an organic electrolyte solution in which a lithium salt is dissolved is swollen in a polymer.

  As shown in FIG. 3, the negative electrode case 10 formed in this manner can be inserted into and removed from the battery case 60 through a negative electrode hole 62 b provided in the upper surface 62 of the battery case 60. In the illustrated embodiment, the negative electrode hole 62b has a similar shape slightly larger than the outer shape of the negative electrode case 10 in plan view. For this reason, the negative electrode case 10 can be inserted into and removed from the battery case 60 through the negative electrode hole 62b.

The lithium-air battery 1 configured as described above is in the two stages of Li → Li ⁺ + e ⁻ at the negative electrode 11 and O ₂ + 2H ₂ O + 4e ⁻ → 4OH ⁻ and OH ⁻ + Li ⁺ → LiOH at the negative electrode 11 during discharge. Lithium hydroxide is produced by this reaction. Since lithium hydroxide is water-soluble, the fine holes of the positive electrode current collector 41 of the positive electrode 40 are not clogged.

On the other hand, at the time of charging, Li ⁺ + e ⁻ → Li at the negative electrode 11, and 4 OH ⁻ → O ₂ + 2H ₂ O + 4 e ⁻ is generated at the positive electrode 40 to generate oxygen. Here, during charging, lithium dentite (sludge) may be generated on the surface of the lithium negative electrode body 15 of the negative electrode 11 or at least one of the second electrolyte 29. When this sludge is generated, the amount of metallic lithium regenerated by the lithium negative electrode body 15 at the time of charging is reduced, and the battery capacity may be reduced. In this case, if the sludge is to be removed, lithium may come into contact with the air and burn, and it is difficult to remove the sludge.

  Therefore, in the lithium-air battery 1 of the present application, when sludge is generated, the negative electrode case 10 in which sludge is generated is detached from the battery case 60, and a new negative electrode case 10 in which sludge is not generated is attached to the battery case 60. Insert it. The determination of the replacement time of the negative electrode case 10 is made based on changes in charge / discharge characteristics (for example, a decrease in battery capacity, an increase in battery resistance, etc.).

  Thus, as described above, since the negative electrode case 10, the lithium negative electrode body 15, the solid electrolyte 50, and the second electrolyte 29 are integrated and accommodated in the negative electrode case 10, lithium is removed when the negative electrode case 10 is inserted and removed. The negative electrode body 15 does not come into contact with air. Further, when the negative electrode 11 is deactivated, a new negative electrode case 10 is inserted into the battery case 60, so that in the lithium-air battery 1, no sludge adheres to the negative electrode 11 and sludge is present in the second electrolyte 29. It can be restored to a non-floating state. Therefore, when the negative electrode is deactivated by the sludge generated during charging / discharging of the lithium air battery 1, the sludge is removed, and the negative electrode 11 is restored without touching the air so that the lithium air battery 1 can be used repeatedly. A lithium-air battery 1 that can be realized can be realized.

  Further, as described above, as shown in FIG. 6, the solid electrolyte 50 is formed in a plate shape, covers the first opening 17, and is fixed inside the negative electrode case 10. There is no possibility of protruding outside the first opening 17. Therefore, as shown in FIG. 3, when the negative electrode case 10 is inserted into and removed from the negative electrode hole 62b formed on the upper surface 62 of the battery case 60, the solid electrolyte 50 comes into contact with the negative electrode hole 62b. The possibility of damage can be prevented.

  In addition, as described above, since the plurality of partition members 21 extend in the direction intersecting each other in the first opening 17 as shown in FIG. 4, the first openings are formed by the plurality of partition members 21. 17 can be partitioned into a plurality of opening portions 17a. For this reason, the area of the opening part 17a becomes smaller than the area of the first opening part 17, and an obstacle comes into contact with the opening part 17a when the negative electrode case 10 is inserted and removed, or an external force acts on the opening part 17a. The fear can be suppressed, and the possibility that the solid electrolyte 50 is damaged can be further prevented.

  Furthermore, as described above, the current collector main body 12a is fixed in a state of being in contact with the plate-like lithium negative electrode body 15 as shown in FIG. The electrode effect of the part 12a can be exhibited effectively. In addition, since the plurality of connection portions 12b protruding from at least two different positions on the outer peripheral portion of the current collector main body portion 12a of the negative electrode current collector 12 are connected to the inner surface of the negative electrode case 10, the negative electrode current collector The body 12 can be more firmly fixed to the negative electrode case 10. For this reason, the plate-like lithium negative electrode body 15 can be firmly fixed to the negative electrode case 10 through the current collector main body 12a. Accordingly, it is possible to prevent the occurrence of inconvenience such as the lithium negative electrode body 15 coming into contact with the solid electrolyte 50 and the solid electrolyte 50 being corroded.

  FIG. 7 is a cross-sectional view of the negative electrode case 10 corresponding to the III-III arrow of FIG.

  Further, according to some embodiments, as shown in FIGS. 3 and 7, the negative electrode hole 62 b is formed in the battery case 10 below the negative electrode hole 62 b formed in the upper surface 10 a of the battery case 60. A guide guide 65 for guiding the movement of the negative electrode case 10 when the negative electrode case 10 is inserted into and removed from the battery case 60 is provided.

  In the illustrated embodiment, the guide guide 65 includes guide members 66 disposed on the outer sides of the four corners of the negative electrode case 10 inserted in the battery case 60 in a plan view. The guide member 66 is bent in an L shape and extends in a bar shape in the vertical direction. The guide member 66 extends from the upper end to the lower end of the space 60 a in the battery case 60.

  Thus, since the guide guide 65 for guiding the movement of the negative electrode case 10 is provided in the battery case 60 below the negative electrode hole 62b, the negative electrode case 10 is connected to the battery case via the negative electrode hole 62b. The insertion / removal operation of the negative electrode case 10 at the time of insertion / removal with respect to 60 can be facilitated.

  FIG. 8 is a rear perspective view of a negative electrode case 10A according to another embodiment. FIG. 9 is a cross-sectional view of a negative electrode case 10A according to another embodiment.

  As shown in FIGS. 8 and 9, the negative electrode case 10 </ b> A according to another embodiment includes a negative electrode portion opposite to the side facing the positive electrode 40 in a state where the negative electrode case 10 </ b> A is inserted into the battery case 60. The first electrolyte 53 exists between the opposite side surface of the case 10A and the inner surface of the battery case 60 (see FIG. 3), and the negative electrode portion case covers the second opening 70 on the opposite side surface of the negative electrode portion case 10A. The solid electrolyte 50A is fixed inside 10A, and the second electrolyte 29A is filled between the solid electrolyte 50A and the lithium negative electrode body 15A. In addition, the negative electrode case 10A according to another embodiment is described only for the differences from the negative electrode case 10 described above, and the same reference numerals are given to the same aspects as the negative electrode case 10 described above, and description thereof is omitted. To do.

  In the illustrated embodiment, as shown in FIG. 9, the negative electrode current collector 12 </ b> A is fixed in a state where the lithium negative electrode bodies 15 and 15 </ b> A are in contact with one surface and the other surface. The lithium negative electrode body 15A fixed to the other surface of the negative electrode current collector 12A is disposed so as to face the solid electrolyte 50A disposed so as to cover the second opening 70 with a gap 71 therebetween. In addition, a gap is formed between the outer periphery of the negative electrode current collector 12A and the inner surface of the negative electrode case 10A, and the second electrolyte 29 and the negative electrode filled on one surface side of the negative electrode current collector 12A through this gap. The second electrolyte 29A filled on the other surface side of the current collector 12A can be distributed.

  Thus, in the negative electrode part case 10A according to another embodiment, the first electrolyte 53 exists between the opposite side surface of the negative electrode part case 10A and the inner surface of the battery case 60, and the second opening 70 is provided on the opposite side surface. The solid electrolyte 50A is fixed inside the negative electrode case 10A so as to cover the second opening 70, and the second electrolyte 29A is filled between the solid electrolyte 50A and the lithium negative electrode body 15A. For this reason, lithium ions can move on both surfaces of the lithium negative electrode bodies 15 and 15A facing the positive electrode 40 side and the opposite surface. Therefore, the charge / discharge characteristics of the lithium air battery 1 can be improved.

  Further, as described above, the negative electrode case 10 is accommodated in the negative electrode case 11, the lithium negative electrode body 15, the solid electrolyte 50, and the second electrolyte 29 as shown in FIG. The battery case 60 is configured to be detachable. For this reason, the lithium negative electrode body 15 does not come into contact with air when the negative electrode case 10 is inserted into and removed from the battery case 60. Further, when the negative electrode 11 is deactivated, a new negative electrode case 10 is inserted into the battery case 60, so that in the lithium-air battery 1, no sludge adheres to the negative electrode 11 and sludge is present in the second electrolyte 29. It can be restored to a non-floating state. Therefore, when the negative electrode is deactivated by the sludge generated during charging / discharging of the lithium air battery 1, the sludge is removed, and the negative electrode 11 is restored without touching the air so that the lithium air battery 1 can be used repeatedly. The negative electrode structure of the lithium-air battery 1 that can be realized can be realized.

  As mentioned above, although the preferable form of this invention was demonstrated, this invention is not limited to said form, A various change in the range which does not deviate from the objective of this invention is possible. For example, the battery case may be provided with a plurality of a pair of electrode groups each including a positive electrode and a negative electrode case in the battery case.

DESCRIPTION OF SYMBOLS 1 Lithium air battery 10, 10A Negative electrode case 10a, 62 Upper surface 10b Side surface 11 Negative electrode 12, 12A Negative electrode collector 12a Current collector main body 12b Connection part 12b1 First connection part 12b2 Second connection part 13 Negative electrode 15 Lithium negative electrode Body 17 First opening portion 17a Opening portion 19, 60a Space portion 21 Partition member 22 Insertion hole portion 25, 71 Clearance 29 Second electrolyte 40 Positive electrode 41 Positive electrode current collector 42 Positive electrode terminal 43 Water repellent layer 44 Catalyst 50, 50A Solid electrolyte 53 First Electrolyte 60 Battery Case 61 Side 61a Hole 62a Positive Hole 62b Negative Hole 65 Guide Guide 66 Guide Member 70 Second Opening 72 Insulating Member

Claims (8)

A negative electrode, a positive electrode disposed at a distance from the negative electrode, a solid electrolyte disposed between the negative electrode and the positive electrode, and a first filled between the solid electrolyte and the positive electrode A lithium-air battery in which the electrolyte is provided in a battery case,
The negative electrode is
A negative electrode current collector serving as an electrode;
A lithium negative electrode body electrically connected to the negative electrode current collector,
The negative electrode, the solid electrolyte disposed with a gap with respect to the lithium negative electrode body and capable of conducting lithium ions between the lithium negative electrode body and the first electrolyte, the lithium negative electrode body, and the A negative electrode case that houses a second electrolyte capable of conducting lithium ions with the solid electrolyte;
The negative electrode case is configured to be detachable with respect to an insertion / removal hole formed on the upper surface of the battery case. The negative electrode case is formed in a box shape, and a first opening is provided on one side surface of the negative electrode case.
The first opening is disposed to face the positive electrode,
The lithium air battery according to claim 1, wherein the solid electrolyte covers the first opening and is fixed inside the negative electrode case. 3. The lithium air according to claim 2, wherein a plurality of partition members for partitioning the first opening into a plurality of opening portions extend in a direction intersecting with each other in the first opening. battery. The negative electrode current collector protrudes from at least two different positions of a current collector body fixed to the plate-like lithium negative electrode body in a state of overlapping and in contact with the outer periphery of the current collector body. A plurality of connecting portions connected to the inner surface of the negative electrode case,
The lithium-air battery according to claim 2 or 3, wherein the lithium negative electrode body is fixed to the negative electrode case through the negative electrode current collector. One of the plurality of connecting portions protrudes upward from an upper portion of the current collector main body portion, and is inserted into an insertion hole portion formed in an upper surface of the negative electrode case. Fixed to
The other one of the plurality of connecting portions protrudes downward from a lower portion of the current collector main body, is connected to the bottom of the negative electrode case, and is fixed to the negative electrode case. The lithium air battery according to claim 4. In the battery case below the insertion / removal hole formed on the upper surface of the battery case, the negative electrode case is inserted into / removed from the battery case via the insertion / removal hole. The lithium air battery according to any one of claims 2 to 5, further comprising a guide for guiding the movement of the negative electrode case. In a state where the negative electrode case is inserted into the battery case, the first electrolyte exists between the opposite side surface of the negative electrode case opposite to the side facing the positive electrode and the inner surface of the battery case. And
A second opening is formed on the opposite side surface of the negative electrode case.
The solid electrolyte is fixed inside the negative electrode case, covering the second opening, and the second electrolyte is filled between the solid electrolyte and the lithium negative electrode body. Item 3. A lithium air battery according to Item 2. A negative electrode, a positive electrode disposed at a distance from the negative electrode, a solid electrolyte disposed between the negative electrode and the positive electrode, and a first filled between the solid electrolyte and the positive electrode An electrolyte is a negative electrode structure that can be inserted into and removed from a lithium-air battery provided in a battery case,
The negative electrode is
A negative electrode current collector serving as an electrode;
A lithium negative electrode body electrically connected to the negative electrode current collector,
The negative electrode, a solid electrolyte disposed with a gap with respect to the lithium negative electrode body and capable of conducting lithium ions between the lithium negative electrode body and the first electrolyte, and the lithium negative electrode body and the solid A negative electrode case containing a second electrolyte capable of conducting lithium ions with the electrolyte;
The negative electrode structure of a lithium air battery, wherein the negative electrode case is detachable from the battery case of the lithium air battery.

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