WO2015176609A1

WO2015176609A1 - Material with surface having multilevel nano micron structure, preparation method thereof and nickel-zinc cell containing material in a positive electrode

Info

Publication number: WO2015176609A1
Application number: PCT/CN2015/078444
Authority: WO
Inventors: 孙晓明; 陆之毅; 吴小超
Original assignee: 北京化工大学
Priority date: 2014-05-22
Filing date: 2015-05-07
Publication date: 2015-11-26
Also published as: CN104051728A; CN104051728B

Abstract

Disclosed is a material with a surface having multilevel nano micron structure. The material comprises: a porous conductive substrate, a cobaltosicoxide primary rectangular micron sheet array growing perpendicularly on the porous conductive substrate, and a plurality of villous nickel oxide secondary nanowires growing on the surface of each primary rectangular micron sheet. Further disclosed are a hydrothermal synthesis method for preparing the material and a cell containing the material in a positive electrode, particularly a nickel-zinc cell. Whlie the material having high specific surface area is used as the electrode material, the electrical contact performance of the electrode is improved, and further the overall electrical property of the electrode and the cell containing the material is improved.

Description

Material having multi-stage nano-micron structure on surface, preparation method thereof and nickel-zinc battery containing same material in positive electrode

Technical field

The invention belongs to the field of inorganic advanced nano material technology

Background technique

Among various batteries, nickel-zinc batteries have a high operating voltage, good energy density and power density, and are a high-energy green environmentally friendly secondary power battery [J. Power Sources, 2000, 88, 202-205]. One of the key factors affecting the performance of the battery is the electrode material, but the general commercial nickel-zinc battery has many problems in its electrode material, such as the zinc electrode is prone to branching, the passivation and the like lead to decay of the cycle life, and the nickel electrode also has expansion. And poisoning phenomenon, easy to cause reduction in charging efficiency and capacity loss. It is still desirable to have better electrode materials and better nickel-zinc batteries to avoid the above problems.

Summary of invention

The invention solves the problem of poor cycle property and low capacity of the general electrode material through the uniquely designed material having a multi-stage nano-micron structure, and has a good application in electrochemical energy storage.

In a first aspect, the present invention is directed to a material having a multi-stage nano-micron structure on its surface, comprising:

Porous conductive substrate;

An array of tricobalt oxide primary rectangular microplates grown perpendicular to the substrate on the porous conductive substrate;

A plurality of fluffy nickel oxide secondary nanowires grown on the surface of each of said primary rectangular microchips.

In a second aspect, the invention relates to a method of preparing a material having a multi-stage nano-micron structure on its surface, comprising the steps of:

a. The porous conductive substrate is placed obliquely in the first reaction vessel, and then the first aqueous solution containing soluble cobalt salt, ammonium fluoride and urea is added to the reaction vessel, and then the reaction vessel is sealed, heated and under autogenous pressure. Performing a first hydrothermal reaction to grow a cobalt hydroxide primary microwire array perpendicular to the substrate on the surface of the porous conductive substrate;

b. taking out the porous conductive substrate, washing and drying;

c. The porous conductive substrate treated in step b is placed obliquely in the second reaction vessel, and then a second aqueous solution containing soluble cobalt salt and urea is added to the reaction vessel, the reaction vessel is sealed, and the temperature is raised and under autogenous pressure. Performing a second hydrothermal reaction such that each of the cobalt hydroxide primary microwires forms a primary rectangular microchip;

d. take out the porous conductive substrate again, wash and dry;

e. The porous conductive substrate treated in step d is placed obliquely in the third reaction vessel, and a third aqueous solution containing soluble nickel salt and urea is added to the reaction vessel, the reaction kettle is sealed, and the temperature is raised and under autogenous pressure. Carry out the third a sub-hydrothermal reaction to grow a plurality of fluffy nickel hydroxide secondary nanowires on a surface of each of said cobalt hydroxide primary rectangular microchips;

f. removing the porous conductive substrate again, washing and drying;

g. calcining the porous electrically conductive substrate in air such that the cobalt hydroxide primary rectangular microsheet is converted to a trittrium cobalt trioxide primary rectangular microplate and the nickel hydroxide secondary nanowire is converted to a nickel oxide secondary nanowire.

In a third aspect, the invention relates to a battery whose cathode material comprises a material having a multi-stage nano-micron structure on the surface of the invention.

In a fourth aspect, the present invention relates to a nickel-zinc battery, the positive electrode material comprising the material having a multi-stage nano-micron structure on the surface of the present invention, the negative electrode material comprising zinc plated on the conductive substrate, wherein the negative electrode material comprises The conductive substrate is the same as or different from the conductive substrate included in the positive electrode material.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of a material having a multi-stage nano-micron structure on the surface of the present invention.

2 is a scanning electron micrograph (SEM) of the material of the present invention, in which it is clearly shown that the array of primary rectangular microcrystals of tricobalt oxide is grown perpendicular to the surface of the substrate, and a plurality of fluff are grown on the surface of each of the primary rectangular microplates of cobalt tetraoxide. Nickel oxide secondary nanowire; wherein the substrate is foamed nickel.

3 is an X-ray diffraction pattern (XRD) of the material shown in FIG. 2. It is discernible from the comparison of the standard spectrum that the primary rectangular microchip composition on the material of the present invention is a tricobalt tetroxide crystal, and the secondary nanowire component is a nickel oxide crystal.

Figure 4 is a cyclic voltammogram of the material of Figure 2, measured with a mercury/mercury oxide electrode as a reference electrode.

Figure 5 is a graph of charge and discharge of the material shown in Figure 2.

Figure 6 is a cycle stability diagram of the material shown in Figure 2.

Figure 7 is a scanning electron micrograph (SEM) of another form of the material of the present invention, in which it is clearly shown that the array of primary rectangular microcrystals of tricobalt oxide grows perpendicular to the surface of the substrate and grows on each of the primary rectangular microplates of cobalt tetraoxide. a fluffy nickel oxide secondary nanowire; wherein the substrate is a carbon fiber felt.

Figure 8 is an X-ray diffraction pattern (XRD) of the material shown in Figure 7. It is discernible from the comparison of the standard spectrum that the primary rectangular microchip composition on the material of the present invention is a cobalt tetraoxide crystal, and the secondary nanowire component is a nickel oxide crystal.

Figure 9 is a cyclic voltammogram of the material of Figure 7, measured with a mercury/mercury oxide electrode as a reference electrode.

Figure 10 is a graph showing the charge and discharge curves of the material shown in Figure 7.

Figure 11 is a cycle stability diagram of the material shown in Figure 7.

Figure 12 is a schematic view showing the structure of a nickel-zinc battery using the material of the present invention as a positive electrode material, wherein the negative electrode includes, but is not limited to, a copper plate which is surface-galvanized.

Figure 13 is a cyclic voltammogram of a nickel-zinc battery of the material shown in Figure 2 as a positive electrode material.

Fig. 14 is a graph showing charge and discharge curves of a nickel-zinc battery as a positive electrode material of the material shown in Fig. 2.

Fig. 15 is a graph showing the rate characteristics of a nickel-zinc battery as the positive electrode material of the material shown in Fig. 2.

Figure 16 is a cycle stability diagram of a nickel-zinc battery of the material shown in Figure 2 as a positive electrode material.

Figure 17 is a photograph of an energization experiment of a simple soft-packed nickel-zinc battery using the material of the present invention as a positive electrode material prepared in a laboratory, in which a surface having a multi-stage nano-micron structure of the present invention is used as a positive electrode, and the surface is plated. A copper plate of zinc is used as a negative electrode, an electrolyte solution is a KOH solution, and a separator is a Celgard type lithium battery separator. Two of the soft-packed nickel-zinc batteries are connected in series to enable the light-emitting diode to emit light.

Detailed description of the invention

Various aspects of the invention are now described in detail.

A first aspect of the invention relates to a material having a multi-stage nano-micron structure on its surface. The porous conductive substrate as used herein refers to a conductive substrate having a porous structure, which may be metal or carbon in material, and may be referred to as a metal foam or a porous carbon fiber felt, respectively. The metal may be selected from any suitable metal, such as copper foam when the metal is copper, and foamed nickel when the metal is nickel. For a more detailed description and preparation of foam metal or porous carbon fiber mat, reference can be made to the existing patent literature. Such foamed metal or porous carbon fiber mats are also commercially available or can be made in accordance with the relevant literature.

A plurality of tricobalt trioxide primary rectangular microplates are grown in an array perpendicular to the surface of the porous electrically conductive substrate. On the surface of each of the primary rectangular microplates of cobalt tetraoxide, a plurality of nickel oxide secondary nanowires are grown in a pile shape. It can be seen that the material of the present invention has a two-stage nano-micron structure, the primary structure is a micro-micron structure, and the secondary structure is a nanowire structure, which may be referred to as a "multi-stage nano-micron structure", that is, a micron having multiple levels. Structure and nanostructure arrangement.

Such a multi-stage nano-micron structure undoubtedly greatly increases the surface area of the material of the present invention and improves its electrical contact efficiency. The inventors have found that the material of the present invention is very suitable as a positive electrode material for a battery, but it is not excluded that the material of the present invention will find other uses in the future.

A second aspect of the invention relates to a method of preparing a material having a multi-stage nano-micron structure on its surface, the steps of which are detailed below:

Step a. The porous conductive substrate is placed obliquely in the first reaction vessel, and then the first aqueous solution containing soluble cobalt salt, ammonium fluoride and urea is added to the reaction vessel, and then the reaction vessel is sealed, heated and under autogenous pressure. A first hydrothermal reaction is performed to grow a cobalt hydroxide primary microwire array perpendicular to the substrate on the surface of the porous electrically conductive substrate. Preferably, the porous electrically conductive substrate is previously cleaned to remove dirt and impurities from the surface. Such washing may be ultrasonically washed in concentrated hydrochloric acid, then transferred to a solvent such as deionized water and ethanol, and ultrasonically washed again. In the first aqueous solution, the concentration of each substance can be adjusted as needed. For example, in a preferred embodiment, the soluble cobalt salt concentration is 0.025-0.1 mol/liter, and the ammonium fluoride concentration is 0.1-0.4 mol/ The urea concentration is from 0.1 to 0.5 mol/l. Of course, other concentration ranges can also be used. The conditions of the first hydrothermal reaction can also be adjusted as needed, for example, a preferred condition is a temperature of 100-120 ° C and a reaction time of 8-12 hours. Upon the first hydrothermal reaction, a primary magnesium hydroxide line is obtained on the porous electrically conductive substrate. By changing the concentration of each substance or changing the conditions of the first hydrothermal reaction, the arrangement density, growth height, and the like of the primary microwire array on the substrate can be adjusted, and these can be specifically explored by a limited experiment. Wherein the soluble cobalt salt is selected from the group consisting of cobalt nitrate, cobalt sulfate or cobalt chloride, or any of their hydrates with water of crystallization. After the completion of the first hydrothermal reaction, the first reactor was cooled to room temperature and then opened.

Step b. The porous conductive substrate is taken out, washed and dried. There is no limitation on the specific washing and drying method. For example, the washing may be carried out by any suitable solvent such as water, ethanol or the like, or by ultrasonic cleaning, and the drying may be carried out in an oven.

Step c. The porous conductive substrate treated in step b is placed obliquely in the second reaction kettle, and then a second aqueous solution containing soluble cobalt salt and urea is added to the reaction vessel, the reaction kettle is sealed, and the temperature is raised and the autogenous pressure is applied. A second hydrothermal reaction is carried out such that each of the cobalt hydroxide primary microwires continues to grow into rectangular microchips, or a plurality of adjacent cobalt hydroxide primary microwires are combined to form a rectangular microchip. In the second aqueous solution, the concentration of each substance may be adjusted as needed. For example, in a preferred embodiment, the soluble cobalt salt concentration is 0.025-0.075 mol/liter, and the urea concentration is 0.1-0.5 mol/liter; The conditions of the second hydrothermal reaction can also be adjusted as needed. For example, a preferred condition is a temperature of 80 to 100 ° C and a reaction time of 6 to 10 hours. The soluble cobalt salt is selected from the group consisting of cobalt nitrate, cobalt sulfate or cobalt chloride, or any of their hydrates with water of crystallization. After the second hydrothermal reaction was completed, the second reactor was cooled to room temperature and then opened.

Step d. The porous conductive substrate was taken out again, washed and dried. There is no limitation on the specific washing and drying method. For example, the washing may be carried out by any suitable solvent such as water, ethanol or the like, or by ultrasonic cleaning, and the drying may be carried out in an oven.

Step e. The porous conductive substrate treated in step d is placed obliquely in the third reaction vessel, and then a third aqueous solution containing soluble nickel salt and urea is added to the reaction vessel, the reaction kettle is sealed, and the temperature is raised and the autogenous pressure is applied. A third hydrothermal reaction is carried out, which is capable of growing a plurality of fluffy nickel hydroxide secondary nanowires on the surface of the aforementioned cobalt hydroxide rectangular microchip. In the third aqueous solution, the concentration of each substance may be adjusted as needed. For example, in a preferred embodiment, the soluble nickel salt concentration is 0.025-0.1 mol/liter, and the urea concentration is 0.1-0.5 mol/liter; The conditions for the third hydrothermal reaction can also be adjusted as needed. For example, a preferred condition is a temperature of 80 to 100 ° C and a reaction time of 6 to 10 hours. The soluble nickel salt is selected from the group consisting of nickel nitrate, nickel sulfate or nickel chloride, or any of their hydrates with water of crystallization. After the completion of the third hydrothermal reaction, the third reactor was cooled to room temperature and then opened.

Step f. The porous conductive substrate was taken out again, washed and dried. There is no limitation on the specific washing and drying method. For example, the washing may be carried out by any suitable solvent such as water, ethanol or the like, or by ultrasonic cleaning, and the drying may be carried out in an oven.

Step g. Calcining the porous electrically conductive substrate in air such that the cobalt hydroxide primary rectangular microchip array is converted into a trittrium cobalt trioxide primary rectangular microchip array and the fluffy nickel hydroxide nanowires are converted to nickel oxide nanowires. The calcination temperature, calcination time, and calcination atmosphere can be adjusted to ensure conversion of cobalt hydroxide to cobalt tetraoxide after calcination, and conversion of nickel hydroxide to nickel oxide. For example, a preferred set of calcination conditions are: a calcination temperature of from 250 to 350 ° C and a calcination time of from 2 to 4 hours.

The above preparation method is synthesized under simple hydrothermal reaction conditions, the method is simple, the cost is low, and the repeatability is good; no organic solvent and surfactant are used, and the environment is very friendly; the obtained product structure is uniform and orderly arranged. More importantly, this is a monolithic material in which cobalt trioxide and nickel oxide, which are electrode active materials, are directly connected to a porous conductive substrate as a current collector, and do not need to be added with a binder, and have a novel structure. Very good electrical conductivity; in addition, by controlling the type and concentration of cobalt and nickel salts in the solution, it is possible to synthesize multi-level nano-micron structures with different sizes and densities, and to control the morphology of the materials. Such a structure avoids the problem that the general powder material is in poor contact with the current collector, the electron transport effect is poor, and the electrode activity can be greatly increased due to the existence of a multi-stage nano-micron structure, especially the presence of numerous pile-like secondary nanowires. The specific surface area of the material improves the electrical contact properties of the material, thereby improving the overall electrical performance of the electrode and battery containing the modified material.

A third aspect of the invention relates to a battery whose positive electrode comprises the material mentioned in the first aspect of the invention. In the battery, the negative electrode material is not particularly limited as long as it can be combined with the material mentioned in the first aspect of the invention. The positive electrode material of the material is matched to generate an electromotive force. A preferred negative electrode material is a surface galvanized substrate, and the material of the substrate is also not particularly limited.

A fourth aspect of the invention relates to a nickel-zinc battery, the positive electrode material comprising the material according to the first aspect of the invention, the negative electrode material comprising zinc plated on a conductive substrate, wherein the conductive substrate and the positive electrode contained in the negative electrode material The conductive substrates contained in the materials may be the same or different. Preferably, the conductive substrate in the negative electrode material is a copper sheet or a titanium sheet. Such a nickel-zinc battery may further comprise a separator and an aqueous alkali metal hydroxide solution containing zincate ions as an electrolyte, and there is no particular requirement for the separator. In an alternative embodiment, the negative electrode material may also be galvanized without pre-plating, but instead contain a soluble zinc salt in the electrolyte, and zinc is electroplated onto the surface of the negative electrode material by in-situ electroplating during charging. Such a nickel-zinc battery can be in the form of a soft pack battery.

detailed description

The invention is further illustrated by the following examples. The examples are merely illustrative and not limiting.

Example 1

a. The foamed nickel substrate was placed obliquely in the first reaction vessel, and then the first reactor containing 0.05 mol/liter of cobalt nitrate, 0.2 mol/liter of ammonium fluoride and 0.25 mol/liter of urea was added to the reactor. An aqueous solution, then sealed the reaction vessel, heated to 120 ° C and maintained at autogenous pressure for 12 hours for a first hydrothermal reaction to grow a cobalt hydroxide primary microwire array perpendicular to the substrate on the surface of the foamed nickel substrate;

b. removing the foamed nickel substrate, washing and drying;

c. The foamed nickel substrate treated in step b is placed obliquely in the second reaction vessel, and a second aqueous solution containing 0.025 mol/liter of cobalt nitrate and 0.25 mol/liter of urea is added to the reactor, and the sealing is sealed. The reaction vessel is heated to 100 ° C and maintained at autogenous pressure for 10 hours for a second hydrothermal reaction, such that each of the cobalt hydroxide primary microwires forms a rectangular particle of cobalt hydroxide, or a plurality of adjacent cobalt hydroxides. The primary micron wires are combined and grown into a rectangular micron chip; the specific growth mechanism is not the focus of the present invention, and in general, the second hydrothermal condition is controlled to finally produce a rectangular particle of cobalt hydroxide;

d. remove the foamed nickel substrate again, wash and dry;

e. The foamed nickel substrate treated in step d is placed obliquely in the third reaction vessel, and a third aqueous solution containing 0.05 mol/liter of nickel nitrate and 0.25 mol/liter of urea is added to the reactor, and the sealing is sealed. The reactor was heated to 100 ° C and maintained at autogenous pressure for 10 hours for a third hydrothermal reaction to grow fluffy nickel hydroxide nanowires on each of the cobalt hydroxide primary rectangular microchips;

f. removing the foamed nickel substrate again, washing and drying;

g. calcining the foamed nickel substrate at 250 ° C for 3 hours in air, the calcination conditions enabling the conversion of the cobalt hydroxide primary rectangular microsheet into a primary rectangular microparticle of cobalt tetraoxide, and converting the nickel hydroxide secondary nanowire to a nickel oxide secondary Nanowires.

The scanning electron micrograph of the obtained material is shown in Fig. 2, the XRD spectrum thereof is shown in Fig. 3, the cyclic voltammogram is shown in Fig. 4, the charge and discharge curve is shown in Fig. 5, and the cycle stability diagram is shown in the drawing. 6.

Example 2

Referring to the method in the first embodiment, the cobalt nitrate in the steps a and c of the embodiment 1 is replaced by cobalt chloride, and the nickel nitrate in the step e is replaced by nickel chloride. The obtained material is the same as the material obtained in the first embodiment. Appearance and performance are very close.

Example 3

Referring to the method of Example 1, the porous conductive substrate was changed from a foamed nickel substrate to a carbon fiber felt, and the rest remained unchanged.

The obtained scanning electron micrograph is shown in Fig. 7, the XRD spectrum thereof is shown in Fig. 8, the cyclic voltammogram is shown in Fig. 9, the charge and discharge graph is shown in Fig. 10, and the cycle stability diagram is shown in Fig. 11.

Example 4

The material obtained in Example 1 was used as a positive electrode, and a conductive copper sheet which was galvanized on the surface was used as a negative electrode, and a 6 mol/L potassium hydroxide aqueous solution was used as an electrolytic solution, and the electrolytic solution further contained zinc ion ions to form a battery.

See Figure 13 for its cyclic voltammogram, Figure 14 for its charge and discharge curve, Figure 15 for the rate characteristic diagram, and Figure 16 for the capacity cycle stability diagram.

Example 5

Based on the battery in Example 4, a celgard 2400 lithium battery separator was used as a separator, and a copper foil was used as a wire. The electrode material and the separator were placed in an aluminum foil package to assemble a simple soft pack battery. Two such soft pack batteries are connected in series, which, after charging, can illuminate the diode and remain illuminated for at least one hour, see Figure 17. After testing, the electrical performance of the battery is as follows: the positive and negative poles have stable capacitance and capacity matching, and the assembled battery has good electrical contact and excellent performance. At a current density of 0.33 A/g, the capacity is 153.33 mAh/g; when the power density is 550 W/kg, the energy density is 251.33 Wh/kg. After 500 cycles of constant current charge and discharge, its capacity attenuation is less than 18%. . This alkaline battery has a higher energy density than a conventional nickel-zinc battery, and can work at a higher power density, and can maintain good stability, and has considerable prospects in practical applications.

Claims

A material having a multi-stage nano-micron structure on the surface, comprising:

Porous conductive substrate;

An array of tricobalt oxide primary rectangular microplates grown perpendicular to the substrate on the porous conductive substrate;

A plurality of fluffy nickel oxide secondary nanowires grown on the surface of each of said primary rectangular microchips.
The material of claim 1 wherein said porous electrically conductive substrate is selected from the group consisting of copper foam, nickel foam or porous carbon fiber mat.
The material of claim 1 wherein said tricobalt trioxide primary rectangular microchip has a size of from 8 to 12 microns in length and from 1.5 to 2.5 microns in width; said nickel oxide secondary nanowires having a size of from 70 to 90 nanometers in length.
A method of preparing a material having a multi-stage nano-micron structure on the surface, comprising the steps of:

a. The porous conductive substrate is placed obliquely in the first reaction vessel, and then the first aqueous solution containing soluble cobalt salt, ammonium fluoride and urea is added to the reaction vessel, and then the reaction vessel is sealed, heated and under autogenous pressure. Performing a first hydrothermal reaction to grow a cobalt hydroxide primary microwire array perpendicular to the substrate on the surface of the porous conductive substrate;

b. taking out the porous conductive substrate, washing and drying;

c. The porous conductive substrate treated in step b is placed obliquely in the second reaction vessel, and then a second aqueous solution containing soluble cobalt salt and urea is added to the reaction vessel, the reaction vessel is sealed, and the temperature is raised and under autogenous pressure. Performing a second hydrothermal reaction such that each of the cobalt hydroxide primary microwires forms a primary rectangular microchip;

d. take out the porous conductive substrate again, wash and dry;

e. The porous conductive substrate treated in step d is placed obliquely in the third reaction vessel, and a third aqueous solution containing soluble nickel salt and urea is added to the reaction vessel, the reaction kettle is sealed, and the temperature is raised and under autogenous pressure. Performing a third hydrothermal reaction to grow a plurality of fluffy nickel hydroxide secondary nanowires on a surface of each of said cobalt hydroxide primary rectangular microchips;

f. removing the porous conductive substrate again, washing and drying;

g. calcining the porous electrically conductive substrate in air such that the cobalt hydroxide primary rectangular microsheet is converted to a trittrium cobalt trioxide primary rectangular microplate and the nickel hydroxide secondary nanowire is converted to a nickel oxide secondary nanowire.
The method of claim 4 wherein said soluble aqueous salt has a concentration of from 0.025 to 0.1 moles per liter, an ammonium fluoride concentration of from 0.1 to 0.4 moles per liter, and a urea concentration of from 0.1 to 0.5 moles per liter of said first aqueous solution. l, the first hydrothermal reaction conditions are: a temperature of 100-120 ° C, a reaction time of 8-12 hours; in the second aqueous solution, a soluble cobalt salt concentration of 0.025-0.075 mol / liter, the urea concentration is 0.1-0.5 mol / liter, the second hydrothermal reaction conditions are: a temperature of 80-100 ° C, a reaction time of 6-10 hours; in the third aqueous solution, a soluble nickel salt concentration of 0.025-0.1 mol / l, the urea concentration is 0.1-0.5 mol / liter, the third hydrothermal reaction conditions are: the temperature is 80-100 ° C, the reaction time is 6-10 hours; wherein the soluble cobalt salt is selected from the group consisting of cobalt nitrate, sulfuric acid Cobalt or cobalt chloride; the soluble nickel salt is selected from the group consisting of nickel nitrate, nickel sulfate or nickel chloride.
The method of claim 4, wherein in the step g, the calcination temperature is from 250 to 350 ° C and the calcination time is from 2 to 4 hours.
A battery, the positive electrode material comprising the material of any one of claims 1-3.
A nickel-zinc battery, the positive electrode material comprising the material according to any one of claims 1 to 3, wherein the negative electrode material comprises zinc plated on the conductive substrate, wherein the conductive substrate contained in the negative electrode material and the positive electrode material are contained The conductive substrates are the same or different.
A nickel-zinc battery according to claim 8, which further comprises a separator and an aqueous alkali metal hydroxide solution containing zincate ions as an electrolytic solution.