JP-2026075294-A - Anode for zinc battery, zinc battery, method for manufacturing a zinc battery anode, and zinc battery anode material

Abstract

[Problem] To provide a negative electrode for zinc batteries that has good manufacturability and can improve the discharge characteristics of the battery. [Solution] The negative electrode for a zinc battery has a negative electrode mixture containing zinc oxide, and in the X-ray diffraction pattern of the negative electrode mixture, the ratio of the peak intensity of the (002) plane (I 002 ) derived from zinc oxide to the peak intensity of the (101) plane (I 101 ) derived from zinc oxide (I 002 / I 101 ) is 0.4 or more. [Selection Diagram] Figure 1

Inventors

• 伴野 嵩敏
• 村瀬 知志
• 山口 同通
• 梶原 剛史
• 伊藤 武

Assignees

• ＦＤＫ株式会社

Dates

Publication Date

20260508

Application Date

20241022

Claims (12)

1. The negative electrode mixture contains zinc oxide, In the X-ray diffraction pattern of the negative electrode mixture, the ratio of the peak intensity of the (002) plane (I 002 ) derived from zinc oxide to the peak intensity of the (101) plane (I 101 ) derived from zinc oxide (I 002 / I 101 ) is 0.4 or more. Negative electrode for zinc batteries.
2. The aforementioned zinc oxide includes zinc oxide particles, The median diameter of the zinc oxide particles is 3 μm or more and 20 μm or less. The negative electrode for a zinc battery according to claim 1.
3. The negative electrode mixture further comprises second zinc oxide particles having a median diameter of 2 μm or less. The negative electrode for a zinc battery according to claim 2.
4. The content of the zinc oxide particles in the negative electrode mixture is 50% by mass or more, relative to the total amount of the zinc oxide particles and the second zinc oxide particles. The negative electrode for a zinc battery according to claim 3.
5. The negative electrode for the zinc battery further comprises a current collector holding the negative electrode mixture, The current collector is a current collector without holes. The negative electrode for a zinc battery according to claim 1.
6. It has a positive electrode, a negative electrode, and an alkaline electrolyte. The negative electrode is the negative electrode for a zinc battery described in any one of claims 1 to 5. Zinc battery.
7. It is a nickel-zinc rechargeable battery. The zinc battery according to claim 6.
8. A step of preparing zinc oxide particles in which the ratio of the peak intensity of the (002) plane (I 002 ) to the peak intensity of the (101) plane (I 101 ) in the X-ray diffraction pattern (I 002 / I 101 ) is 0.5 or more, A step of preparing a negative electrode mixture containing the zinc oxide particles, including, A method for manufacturing a negative electrode for a zinc battery.
9. The median diameter of the zinc oxide particles is 3 μm or more and 20 μm or less. A method for manufacturing a negative electrode for a zinc battery according to claim 8.
10. In the step of preparing the negative electrode mixture, The negative electrode mixture comprises the zinc oxide particles and second zinc oxide particles having a median diameter of 2 μm or less. A method for manufacturing a negative electrode for a zinc battery according to claim 9.
11. The content of the second zinc oxide particles in the negative electrode mixture is 50% by mass or more, relative to the total amount of the zinc oxide particles and the second zinc oxide particles. A method for manufacturing a negative electrode for a zinc battery according to claim 10.
12. The zinc oxide particles include those in which, in the X-ray diffraction pattern, the ratio of the peak intensity of the (002) plane (I 002 ) to the peak intensity of the (101) plane (I 101 ) (I 002 / I 101 ) is 0.5 or more. Anode material for zinc batteries.

Description

This invention relates to a negative electrode for a zinc battery, a zinc battery, a method for manufacturing a negative electrode for a zinc battery, and a negative electrode material for a zinc battery. Known zinc batteries include nickel-zinc batteries, zinc-air batteries, and silver-zinc batteries. For example, a nickel-zinc secondary battery, a type of nickel-zinc battery, replaces the hydrogen storage alloy anode of a nickel-metal hydride secondary battery with an anode containing zinc or a zinc compound. Zinc is abundant, inexpensive, and has a low environmental impact. Furthermore, nickel-zinc secondary batteries have advantages such as a high open-circuit voltage of 1.8V, high theoretical energy density, and high output. Due to these characteristics, development is progressing in recent years for energy storage and automotive applications as a replacement for lead-acid batteries. Such zinc batteries are required to have improved discharge characteristics, for example, high-power characteristics (discharge characteristics at high power) that can handle increased loads. In contrast, Patent Document 1 discloses a method for manufacturing a negative electrode for a zinc battery using a negative electrode mixture containing zinc oxide particles with an average particle diameter of 0.28 μm or less. Patent Document 2 discloses a method for manufacturing a negative electrode for a zinc battery using a negative electrode mixture containing zinc oxide particles with an average particle diameter of less than 0.60 μm. Thus, by using zinc oxide particles with a relatively small average particle diameter, it is being investigated that the specific surface area can be increased, thereby improving the utilization rate of the active material. Japanese Patent Publication No. 2020-087703Japanese Patent Publication No. 2019-133769 Figure 1 is a perspective view showing a partially cut nickel-zinc secondary battery according to one embodiment of the present invention.Figure 2 shows the X-ray diffraction patterns of the zinc oxide powder used in the examples and comparative examples.Figure 3 shows the measurement results of the particle size distribution of the zinc oxide powder used in the examples and comparative examples.Figure 4 shows the X-ray diffraction patterns of the negative electrodes recovered from the batteries of the examples and comparative examples. The inventors attempted to increase the particle size of zinc oxide particles in order to improve manufacturability. Generally, zinc oxide particles are produced by melting and vaporizing metallic zinc and then oxidizing it in air. As a result, the zinc oxide particles obtained usually have a small particle size of 1 μm or less. In response to this, the inventors have found that relatively large zinc oxide particles can be obtained by sintering zinc oxide powder at a temperature of 1000°C or higher and then grinding it to the desired size. Furthermore, they have found that the zinc oxide particles obtained in this way, despite having a large particle size and a small specific surface area, can improve the discharge characteristics of batteries. Specifically, they can reduce the voltage drop of the battery when discharged under load and improve the discharge characteristics at high output. Furthermore, the zinc oxide particles obtained in this manner differ from those obtained by conventional methods in that the c-axis specific peak intensity in the powder X-ray diffraction pattern is increased, and it was found that they have a highly regular arrangement structure with respect to the c-axis and exhibit anisotropy. In other words, it is thought that during the sintering and subsequent pulverization process, crystal grain growth, oxygen vacancies, and distortion of the crystal structure of zinc oxide occur, resulting in the increased c-axis specific intensity in the powder X-ray diffraction pattern. Furthermore, although the reason why the zinc oxide particles described above improve the discharge characteristics of the battery despite their small specific surface area is not clear, it is thought that the increased anisotropy of the zinc oxide particles results in a greater number of highly reactive crystal faces, leading to an increased reaction area and thus higher reactivity. In other words, in the present invention, zinc oxide particles having a ratio of the peak intensity of the (002) plane (I 002 ) to the peak intensity of the ( 101 ) plane (I 101) in the X-ray diffraction pattern (peak intensity ratio (I 002 / I 101 )) of 0.5 or more can be used as an electrode material for a battery, preferably a negative electrode material for a zinc battery, and more preferably a negative electrode active material for a zinc battery. Furthermore, a negative electrode obtained using such a negative electrode material has a peak intensity ratio (I 002 / I 101 ) of 0.4 or more for the zinc oxide particles or a negative electrode mixture containing them. The embodiments o