JP2019106284A - Zinc battery negative electrode and zinc battery - Google Patents

Abstract

To provide a zinc battery negative electrode capable of obtaining excellent life performance, and a zinc battery including the same.SOLUTION: The zinc battery negative electrode has a negative electrode material containing an active material containing zinc and a ferroelectric substance. The zinc battery includes the same.SELECTED DRAWING: None

Description

  The present invention relates to a zinc battery negative electrode and a zinc battery.

  As zinc batteries using zinc negative electrodes, nickel zinc batteries, air zinc batteries, silver zinc batteries and the like are known. For example, since a nickel zinc battery is a water based battery using a water based electrolyte such as a potassium hydroxide aqueous solution, it has high safety, and a combination of a zinc electrode and a nickel electrode makes it possible to obtain a high electromotive force as a water based battery. It is known to have. Furthermore, nickel zinc batteries are applicable to industrial applications (for example, applications such as backup power supplies) and automotive applications (for example, applications such as hybrid vehicles) due to their low cost in addition to excellent input / output performance. Sex is being considered.

The charge / discharge reaction of the nickel zinc battery proceeds, for example, according to the following formula (discharge reaction: rightward, charge reaction: leftward).
(Positive _{electrode) 2NiOOH + 2H 2 O + 2e} - → 2Ni (OH) 2 + 2OH -
(Negative ^{electrode) Zn + 2OH - → Zn (} OH) 2 + 2e -

As shown in the above formula, in a zinc battery, zinc hydroxide (Zn (OH) ₂ ) is generated by a discharge reaction. Zinc hydroxide is soluble in the electrolyte, and when zinc hydroxide is dissolved in the electrolyte, tetrahydroxy zincate ions ([Zn (OH) ₄ ] ²⁻ ) diffuse into the electrolyte. As a result, the morphological change of the negative electrode progresses and the distribution of the charging current becomes uneven, and the like, precipitation of zinc occurs locally on the negative electrode, and dendrites (dendrite crystals) are generated. In a zinc battery, when dendrite grows due to repeated charging and discharging, the dendrite may penetrate the separator and a short circuit may occur to deteriorate the life performance (for example, see Patent Document 1 below).

JP-A-58-126665

  For such zinc batteries, it is required to improve the life performance.

  This invention is made in view of the said situation, and it aims at providing the zinc battery negative electrode which can obtain the outstanding lifetime performance, and the zinc battery provided with the said negative electrode.

  The negative electrode for a zinc battery according to the present invention has a negative electrode material containing an active material containing zinc and a ferroelectric.

  According to the negative electrode for a zinc battery according to the present invention, excellent life performance can be obtained in the zinc battery.

  The ferroelectric preferably includes at least one selected from the group consisting of barium titanate, calcium titanate, strontium titanate, barium zirconate, calcium zirconate, and strontium zirconate, and includes barium titanate. Is more preferred.

  The content of the ferroelectric is preferably 50% by mass or less based on the total mass of the negative electrode material.

  The zinc battery according to the present invention comprises the above-described zinc battery negative electrode.

  According to the present invention, excellent life performance can be obtained in a zinc battery.

It is a figure for demonstrating an example of the factor from which the effect of this invention is acquired. It is a figure for demonstrating an example of the factor from which the effect of this invention is acquired. It is a figure which shows the evaluation result of lifetime performance. It is a figure which shows the evaluation result of discharge performance.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

  Examples of zinc batteries (for example, zinc secondary batteries) according to the present embodiment include nickel zinc batteries, air zinc batteries, silver zinc batteries and the like. As a basic composition of a zinc battery concerning this embodiment, composition same as a conventional zinc battery can be used.

  The negative electrode (negative electrode for zinc battery) in the zinc battery according to the present embodiment has a negative electrode material containing an active material containing zinc and a ferroelectric. By using such a negative electrode, excellent life performance can be obtained in a zinc battery. Although the cause by which such an effect is acquired is not clear, the present inventors guess as follows. FIG. 1 and FIG. 2 are diagrams for explaining an example of factors that can obtain the effects of the present invention. In FIG.1 and FIG.2, the code | symbol 1 shows a negative electrode, the code | symbol 1a shows a negative electrode collector, and the code | symbol 1b shows a negative electrode material. The code | symbol 2 shows a separator. The code | symbol 3 shows a positive electrode. 1 and 2 differ in the presence or absence of the ferroelectric in the negative electrode material.

That is, in the negative electrode of a zinc battery, zinc hydroxide (Zn (OH) ₂ ) is generated by a discharge reaction. Then, when zinc hydroxide is dissolved in the electrolytic solution, tetrahydroxyzinc acid ion ([Zn (OH) ₄ ] ²⁻ ) is generated. Here, in the case where the tetrahydroxy zincate ion is diffused and can be largely moved, the tetra hydroxide zincate ion is diffused to the outside of the negative electrode as shown in FIG. 1 as the charge and discharge cycle progresses, It is possible that zinc hydroxide or zinc is locally deposited on a part of the negative electrode material (in FIG. 1, the lower end of the negative electrode material) from tetrahydroxyzinc acid ion in the electrolytic solution to cause the negative electrode active material to fall off. is there. In this case, the capacity decreases due to the loss of the negative electrode active material as the charge and discharge cycles progress, and the life performance is degraded.

  On the other hand, in the zinc battery according to the present embodiment, the negative electrode material contains a ferroelectric. When polarization occurs in a ferroelectric (for example, a ferroelectric particle), a positive charge is generated on one surface side of the ferroelectric, and the other surface of the ferroelectric (the surface opposite to the one surface) side Negative charge occurs on the When such a ferroelectric is present in the negative electrode material, the tetrahydroxy zincate ion generated at the negative electrode is adsorbed on the surface on the positive charge side of the dielectric, as shown in FIG. It is suppressed that the acid ion diffuses and moves largely. As a result, loss of the negative electrode active material is suppressed, so that excellent life performance can be obtained.

  Hereinafter, a nickel zinc battery will be described as an example of the zinc battery according to the present embodiment.

  The zinc battery according to the present embodiment includes, for example, a battery case, an electrolytic solution, and an electrode assembly (for example, an electrode plate assembly). The electrode group and the electrolytic solution are contained in the battery case. The zinc battery according to the present embodiment may be either before or after formation.

  The electrolytic solution contains, for example, a solvent and an electrolyte. Examples of the solvent include water (for example, ion exchanged water) and the like. As an electrolyte, a basic compound etc. are mentioned, Alkali metal hydroxides, such as potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH), etc. are mentioned. The zinc battery according to the present embodiment can be used as an alkaline zinc battery using an alkaline electrolyte. The electrolytic solution may contain components other than the solvent and the electrolyte, and for example, contains potassium phosphate, potassium fluoride, potassium carbonate, sodium phosphate, sodium fluoride, zinc oxide, antimony oxide, titanium dioxide, etc. May be

  The electrode group includes, for example, a separator, and a positive electrode (positive electrode plate or the like) and a negative electrode (negative electrode plate or the like) facing each other via the separator. In the electrode group, the positive electrodes and the negative electrodes are connected by, for example, a strap.

  The separator may be, for example, a separator having a flat plate shape, a sheet shape or the like. Examples of the separator include polyolefin-based microporous membranes, nylon-based microporous membranes, oxidation-resistant ion exchange resin membranes, cellophane-based regenerated resin membranes, inorganic-organic separators, and polyolefin-based nonwoven fabrics.

  The positive electrode includes, for example, a positive electrode current collector and a positive electrode material supported by the positive electrode current collector.

  The positive electrode current collector constitutes a conductive path for current from the positive electrode material. The positive electrode current collector has, for example, a flat plate shape, a sheet shape or the like. The positive electrode current collector may be a current collector having a three-dimensional network structure formed of a foam metal, an expanded metal, a punching metal, a felt of a metal fiber, or the like. The positive electrode current collector is made of a material having conductivity and alkali resistance. As such a material, for example, a material which is stable even at the reaction potential of the positive electrode (a material having a redox potential nobler than the reaction potential of the positive electrode, a protective coating such as an oxide film is formed on the substrate surface in an alkaline aqueous solution) And the like) can be used. Further, in the positive electrode, decomposition reaction of the electrolytic solution proceeds as a side reaction to generate oxygen, but a material having a high oxygen overvoltage is preferable in that the progress of such a side reaction can be suppressed. Specific examples of the material constituting the positive electrode current collector include metal materials plated with platinum, nickel, nickel and the like (copper, brass, steel and the like), and the like.

  The positive electrode material may be layered (positive electrode material layer). For example, the positive electrode material layer may be formed on the positive electrode current collector, and when the positive electrode current collector has a three-dimensional network structure, the positive electrode material is filled between the meshes of the positive electrode current collector. A material layer may be formed.

  The positive electrode material contains a positive electrode active material. Examples of the positive electrode active material include nickel oxyhydroxide (NiOOH) and nickel hydroxide. The positive electrode material contains, for example, nickel oxyhydroxide in a fully charged state, and contains nickel hydroxide in a discharged state. The content of the positive electrode active material may be, for example, 50 to 95% by mass based on the total mass of the positive electrode material.

  The positive electrode material can contain an additive. As an additive, a binder etc. are mentioned. Examples of the binder include hydrophilic or hydrophobic polymers, and hydroxypropyl methylcellulose (HPMC), carboxymethylcellulose (CMC), sodium polyacrylate (SPA), and fluorine-based polymer (polytetrafluoroethylene (PTFE) Etc.). The content of the binder may be, for example, 0.01 to 5 parts by mass with respect to 100 parts by mass of the positive electrode active material.

  The negative electrode includes, for example, a negative electrode current collector and a negative electrode material supported by the negative electrode current collector.

  The negative electrode current collector constitutes a conductive path for current from the negative electrode material. The negative electrode current collector has, for example, a flat plate shape, a sheet shape or the like. The negative electrode current collector may be a current collector having a three-dimensional network structure formed of a foam metal, an expanded metal, a punching metal, a felt of a metal fiber, or the like. The negative electrode current collector is made of a material having conductivity and alkali resistance. As such a material, for example, a material which is stable even at the reaction potential of the negative electrode (a material having a redox potential nobler than the reaction potential of the negative electrode, a protective film such as an oxide film is formed on the substrate surface in an alkaline aqueous solution) And the like) can be used. In the negative electrode, the decomposition reaction of the electrolytic solution proceeds as a side reaction to generate hydrogen, but a material having a high hydrogen overvoltage is preferable in that the progress of such a side reaction can be suppressed. Specific examples of the material constituting the negative electrode current collector include metal materials (copper, brass, steel, nickel, etc.) plated with metal such as zinc, lead, tin, tin and the like.

  The negative electrode material may be layered (negative electrode material layer). For example, the negative electrode material layer may be formed on the negative electrode current collector, and when the negative electrode current collector has a three-dimensional network structure, the negative electrode material is filled between the meshes of the negative electrode current collector. A material layer may be formed.

  In the present embodiment, the negative electrode material contains a negative electrode active material containing zinc and a ferroelectric (excluding a compound corresponding to the active material containing zinc). The negative electrode according to the present embodiment may be either before or after formation.

  Examples of the negative electrode active material containing zinc include metallic zinc, zinc oxide, zinc hydroxide and the like. The negative electrode material contains, for example, metallic zinc in a fully charged state, and zinc oxide and zinc hydroxide in a discharged state.

  The content of the negative electrode active material is preferably in the following range based on the total mass of the negative electrode material. The content of the negative electrode active material is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 75% by mass or more, from the viewpoint of easily achieving both excellent life performance and high-rate discharge performance. The content of the negative electrode active material is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 85% by mass or less, from the viewpoint of easily achieving both excellent life performance and high-rate discharge performance. From these viewpoints, the content of the negative electrode active material is preferably 50 to 95% by mass. The content of the negative electrode active material is preferably more than 75% by mass, and more preferably 80% by mass or more, from the viewpoint of achieving further excellent life performance at high discharge rates (for example, discharge rates exceeding 5C). The content of the negative electrode active material is preferably less than 83% by mass, and more preferably 80% by mass or less, from the viewpoint of achieving further excellent life performance at a low discharge rate (for example, a discharge rate of 5C or less).

  A ferroelectric is a substance in which electric dipoles are aligned without an external electric field, and the direction of the electric dipole can be changed by the electric field. As the ferroelectric, a material having alkali resistance can be used. The relative permittivity of the ferroelectric is, for example, 1000 or more. The crystal structure of the ferroelectric includes a perovskite structure, a bismuth layer structure, a tungsten bronze structure and the like.

  The ferroelectric material is at least one selected from the group consisting of barium titanate, calcium titanate, strontium titanate, barium zirconate, calcium zirconate, and strontium zirconate from the viewpoint of obtaining further excellent life performance. It is preferable to contain, and it is more preferable to contain barium titanate.

  The content of the ferroelectric is preferably in the following range based on the total mass of the negative electrode material. The content of the ferroelectric is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 5% by mass or more, particularly preferably 7% by mass or more, from the viewpoint of obtaining further excellent life performance. Preferably, 10% by mass or more is very preferable. The content of the ferroelectric is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, from the viewpoint of easily achieving both excellent life performance and high-rate discharge performance. % Or less is particularly preferable, and 20% by mass or less is very preferable. From these viewpoints, the content of the ferroelectric is preferably 0.1 to 50% by mass, more preferably 0.1 to 40% by mass, and still more preferably 0.1 to 30% by mass. The content of the ferroelectric is preferably less than 20% by mass, and more preferably 15% by mass or less, from the viewpoint of achieving further excellent life performance at a high discharge rate (for example, a discharge rate exceeding 5C). The content of the ferroelectric is preferably more than 11% by mass, and more preferably 15% by mass or more, from the viewpoint of achieving further excellent life performance at a low discharge rate (for example, a discharge rate of 5C or less).

  The content of the ferroelectric is preferably in the following range with respect to 100 parts by mass of the negative electrode active material. The content of the ferroelectric is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 7 parts by mass or more, and particularly preferably 10 parts by mass or more from the viewpoint of obtaining further excellent life performance. The content of the ferroelectric is preferably 90 parts by mass or less, more preferably 50 parts by mass or less, and still more preferably 30 parts by mass or less, from the viewpoint of easily achieving both excellent life performance and high-rate discharge performance. From these viewpoints, the content of the ferroelectric is preferably 1 to 90 parts by mass. The content of the ferroelectric is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, from the viewpoint of easily achieving both excellent life performance and high rate discharge performance at a low discharge rate (for example, a discharge rate of 5 C or less). preferable. The content of the ferroelectric is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, from the viewpoint of easily achieving both long life performance and high rate discharge performance at high discharge rates (for example, discharge rates exceeding 5 C). preferable.

  The negative electrode material can contain an additive other than the negative electrode active material and the ferroelectric. As an additive, a binder etc. are mentioned. As the binder, polytetrafluoroethylene, hydroxyethyl cellulose, polyethylene oxide, polyethylene, polypropylene and the like can be mentioned. The content of the binder may be, for example, 0.5 to 10 parts by mass with respect to 100 parts by mass of the negative electrode active material.

  The method of manufacturing a nickel zinc battery according to the present embodiment includes, for example, an electrode manufacturing step of obtaining an electrode (positive electrode and negative electrode), and an assembly step of assembling a component including the electrode to obtain a nickel zinc battery.

  In the electrode manufacturing process, a positive electrode and a negative electrode are manufactured. For example, a paste-like electrode material (electrode material paste) is obtained by adding a solvent (for example, water) to the raw material of the electrode material (positive electrode material and negative electrode material) and kneading, and then using the electrode material paste Form a material layer.

  As a raw material of positive electrode material, the raw material (for example, nickel hydroxide) of a positive electrode active material, an additive (for example, the said binder), etc. are mentioned. As a raw material of the negative electrode material, a raw material of a negative electrode active material (for example, metal zinc, zinc oxide and zinc hydroxide), a ferroelectric, an additive (for example, the above-mentioned binder) and the like can be mentioned.

  Examples of a method of forming an electrode material layer include a method of obtaining an electrode material layer by applying or filling an electrode material paste on a current collector and then drying it. The electrode material layer may have its density increased by pressing or the like, as necessary.

  In the assembly process, for example, first, the positive electrode and the negative electrode obtained in the electrode manufacturing process are alternately stacked via a separator, and the positive electrode and the negative electrode are connected by a strap to produce an electrode group. Next, this electrode group is placed in a battery case, and then a lid is adhered to the upper surface of the battery case to obtain an unformed nickel zinc battery.

  Next, the electrolytic solution is poured into the battery case of an unformed nickel zinc battery, and then left for a fixed time. Then, a nickel zinc battery is obtained by performing conversion by charging under predetermined conditions. The formation conditions can be adjusted according to the properties of the electrode active material (positive electrode active material and negative electrode active material).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, although an example of a nickel zinc battery has been described in the above embodiment, the zinc battery may be an air zinc battery (for example, an air zinc secondary battery) whose positive electrode is an air electrode, and the positive electrode is a silver oxide electrode. It may be a silver-zinc battery (for example, a silver-zinc secondary battery).

  As an air electrode of an air zinc battery, the well-known air electrode used for an air zinc battery can be used. The air electrode includes, for example, an air electrode catalyst, an electron conductive material, and the like. As the air electrode catalyst, an air electrode catalyst that also functions as an electron conductive material can be used.

  As an air electrode catalyst, what functions as a positive electrode in an air zinc battery can be used, and various air electrode catalysts which can use oxygen as a positive electrode active material can be used. As an air electrode catalyst, carbon-based materials (graphite etc.) having a redox catalyst function, metal materials (platinum, nickel etc.) having a redox catalyst function, inorganic oxide materials (perovskite-type oxide having a redox catalyst function) And manganese dioxide, nickel oxide, cobalt oxide, spinel oxide and the like). The shape of the cathode catalyst is not particularly limited, but may be, for example, in the form of particles. The content of the air electrode catalyst in the air electrode may be 5 to 70% by volume, may be 5 to 60% by volume, or 5 to 50% by volume with respect to the total amount of the air electrode. It is also good.

  As the electron conductive material, a material having conductivity and capable of electron conduction between the cathode catalyst and the separator can be used. Electron conductive materials include carbon blacks such as ketjen black, acetylene black, channel blacks, furnace blacks, lamp blacks, thermal blacks, etc .; natural graphites such as scaly graphites; graphites such as artificial graphites and exfoliated graphites; Conductive fibers such as carbon fibers and metal fibers; metal powders such as copper, silver, nickel, and aluminum; organic electron conductive materials such as polyphenylene derivatives; and arbitrary mixtures of these. The shape of the electron conductive material may be in the form of particles or other shapes. The electron conductive material is preferably used in a form that provides a continuous phase in the thickness direction at the air electrode. For example, the electron conducting material may be a porous material. In addition, the electron conductive material may be in the form of a mixture or complex with an air electrode catalyst, and as described above, may be an air electrode catalyst that also functions as an electron conductive material. The content of the electron conductive material in the air electrode may be 10 to 80% by volume, may be 15 to 80% by volume, or 20 to 80% by volume with respect to the total amount of the air electrode. May be

  As a silver oxide electrode of a silver-zinc battery, the well-known silver oxide electrode used for a silver-zinc battery can be used. The silver oxide electrode contains, for example, silver (I) oxide.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples.

<Fabrication of nickel zinc battery>
Example 1
An expanded nickel with a porosity of 90% was prepared as a positive electrode current collector. Then, a positive electrode material paste was produced by stirring a mixed solution obtained by mixing nickel hydroxide powder, metallic cobalt, cobalt hydroxide, CMC, PTFE, and ion exchange water. At this time, the mass ratio of the solid content was adjusted to “nickel hydroxide: metal cobalt: cobalt hydroxide: CMC: PTFE = 85: 8: 5: 1: 1”. The water content of the positive electrode material paste was adjusted to 27.5% by mass based on the total mass of the positive electrode material paste. Subsequently, after apply | coating a positive electrode material paste on a positive electrode collector, it dried at 80 degreeC for 30 minutes. Then, it pressure-molded by the roll press and obtained the positive electrode which has a positive electrode material layer.

  As a negative electrode current collector, a steel plate punching metal plated with tin and having a porosity of 60% was prepared. Subsequently, a negative electrode material paste was produced by stirring a mixed solution obtained by mixing zinc oxide, metallic zinc, barium titanate, PTFE, and ion exchange water. At this time, the mass ratio of the solid content was adjusted to "zinc oxide: metallic zinc: barium titanate: PTFE = 50: 25: 20: 5". The water content of the negative electrode material paste was adjusted to 32.5% by mass based on the total mass of the negative electrode material paste. Next, the negative electrode material paste was applied onto the negative electrode current collector, and then dried at 80 ° C. for 30 minutes. Then, it pressure-molded by the roll press and obtained the negative electrode which has a negative electrode material layer.

  For the separator, Celgard 2500 as a microporous membrane and VL 100 (manufactured by Nippon High Paper Industry) as a non-woven fabric were used respectively. The microporous membrane was hydrophilized with surfactant Triton-X100 (manufactured by Dow Chemical Co.) before assembly of the battery. The hydrophilization treatment was performed by immersing the microporous membrane in an aqueous solution containing Triton-X100 in an amount of 1% by mass for 24 hours and then drying for 1 hour at room temperature. Furthermore, the microporous film was cut into a predetermined size, folded in half, and heat-sealed on the side to form a bag. One sheet of each of the positive electrode and the negative electrode was housed in a microporous film processed into a bag shape. The nonwoven fabric used what was cut | judged to the predetermined | prescribed size.

  After laminating the positive electrode contained in the bag-like microporous membrane, the negative electrode contained in the bag-like microporous membrane, and the non-woven fabric, electrodes of the same polarity are connected by straps to form an electrode group (electrode plate group ) Was produced. The electrode group had one positive electrode and two negative electrodes, and a non-woven fabric was disposed between the positive electrode and the negative electrode. After arranging this electrode group in the battery case, a lid was adhered to the upper surface of the battery case to obtain an unformed nickel zinc battery. Then, potassium hydroxide (KOH) and lithium hydroxide (LiOH) were mixed with ion exchanged water to prepare an electrolytic solution (potassium hydroxide concentration: 30% by mass, lithium hydroxide concentration: 1% by mass). Then, after the electrolytic solution was injected into the battery case of the non-formed nickel zinc battery, it was left for 24 hours. Thereafter, the battery was charged under the conditions of 16 mA and 15 hours to produce a nickel zinc battery having a nominal capacity of 160 mAh.

(Example 2)
A nickel zinc battery was prepared in the same manner as in Example 1, except that the mass ratio of the solid content in the preparation of the negative electrode material paste was changed to "zinc oxide: metallic zinc: barium titanate: PTFE = 55: 28: 11: 6". Made.

(Comparative example 1)
A nickel zinc battery was produced in the same manner as in Example 1 except that the mass ratio of the solid content in the preparation of the negative electrode material paste was changed to "zinc oxide: metallic zinc: PTFE = 63: 32: 5".

<Battery performance evaluation>
The cycle life performance and the high rate discharge performance were evaluated using the nickel zinc battery.

(Cycle life performance evaluation)
A test (25 ° C.) in which the following operation is one cycle was performed on the nickel zinc battery, and the discharge capacity of each cycle was measured. And the maintenance factor (%) of the discharge capacity at each cycle to the discharge capacity at the first cycle was calculated. The results are shown in FIG. In the example, it is confirmed that the cycle life performance is superior to the comparative example.
・ 160mA (1C), constant voltage charge of 1.9V (charge termination when the current value decreases to 8mA (0.05C))
・ 80 mA (0.5 C) constant current discharge until the battery voltage reaches 1.1 V

  The “C” is a relative expression of the magnitude of the current when performing constant current discharge of the rated capacity from the fully charged state. The “C” means “discharge current value (A) / battery capacity (Ah)”. For example, a current capable of discharging the rated capacity in one hour is expressed as “1 C”, and a current capable of discharging in two hours is expressed as “0.5 C”.

(High rate discharge performance evaluation)
After charging the nickel-zinc battery at a constant voltage of 25 ° C., 160 mA (1 C) and 1.9 V until the current value falls to 8 mA (0.05 C), the battery voltage reaches 1.1 V The nickel zinc battery was discharged at a constant current of 8 mA (0.05 C), 32 mA (0.2 C), 160 mA (1 C), 480 mA (3 C), 800 mA (5 C) or 1600 mA (10 C), and the discharge capacity was measured. . The ratio of the discharge capacity at each discharge current to the discharge capacity at 0.05 C (discharge capacity ratio (%)) was calculated. The results are shown in Table 1 and FIG. When Example 1 and Example 2 are compared, it is confirmed that the discharge capacity of Example 1 is superior to Example 2. Further, when the discharge current is 5 C or less, the discharge capacity ratio of Example 1 and Example 2 is equal, but when the discharge current exceeds 5 C, the discharge capacity ratio of Example 2 is Example 1 It is confirmed that it is superior to the above.

  1: Negative electrode, 1a: Negative electrode current collector, 1b: Negative electrode material, 2: Separator, 3: Positive electrode.

Claims (5)

  A negative electrode for a zinc battery, comprising a negative electrode material containing an active material containing zinc and a ferroelectric.   The zinc battery according to claim 1, wherein the ferroelectric includes at least one selected from the group consisting of barium titanate, calcium titanate, strontium titanate, barium zirconate, calcium zirconate, and strontium zirconate. Negative electrode.   The zinc battery negative electrode according to claim 1, wherein the ferroelectric material includes barium titanate.   The zinc battery negative electrode according to any one of claims 1 to 3, wherein the content of the ferroelectric is 50% by mass or less based on the total mass of the negative electrode material.   A zinc battery comprising the zinc battery negative electrode according to any one of claims 1 to 4.

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