Negative electrode material for reducing internal resistance increase in vibration process of alkaline zinc-manganese battery and preparation method of negative electrode material

Abstract

The invention relates to the technical field of alkaline batteries, in particular to a negative electrode material for reducing internal resistance increase in the vibration process of an alkaline zinc-manganese battery and a preparation method of the negative electrode material. The negative electrode material is composed of the following components: 60 to 63 wt% of mercury-free alloy zinc powder, 9 to 11 wt% of potassium hydroxide, 22 to 24 wt% of deionized water, 2 to 4 wt% of carbon nanotube, 0.5 to 1.5 wt% of sodium polyacrylate, 0.5 to 1.5 wt% of bismuth oxide, and 0.04 to 0.06 wt% of a betaine surfactant. The preparation method of the negative electrode material comprises the following steps: mixing potassium hydroxide and deionized water to obtain a solution, ball-milling and mixing mercury-free alloy zinc powder, two carbon nanotubes, sodium polyacrylate, bismuth trioxide and dodecyl ethyoxyl sulphobetaine, adding a potassium hydroxide solution, carrying out wet stirring treatment, and carrying out vacuum defoaming, so as to obtain the mercury-free alloy zinc-based negative electrode material. The alkaline zinc-manganese battery negative electrode material is obtained. Through the effective implementation of the invention, the carbon nanotubes are introduced into the zinc paste to form a three-dimensional conductive network; a compact interface layer is formed through in-situ reaction of bismuth trioxide and zinc, and dendritic crystal growth is inhibited; and in combination with a flexible binder sodium polyacrylate, vibration energy is absorbed, the internal resistance increase of the battery in the vibration process can be remarkably reduced, and the open-circuit voltage and the internal resistance of the prepared battery before and after vibration are basically kept consistent.

Description

Technical Field

[0001] The present invention relates to the technical field of alkaline batteries, in particular to a negative electrode material capable of reducing the increase in internal resistance of an alkaline zinc-manganese battery during vibration, and a preparation method thereof. Background Art

[0002] Alkaline zinc-manganese dioxide (ZnMn) batteries are mercury- and cadmium-free, comply with international environmental standards, and are inexpensive, offering uniform discharge and low self-discharge rates. They are widely used in smart homes, security equipment, digital products, medical electronics, and other fields. However, in high-vibration environments such as power tools and military equipment, alkaline ZnMn batteries are susceptible to problems such as particle pulverization, electrolyte imbalance, and dendrite growth in the Zn anode. These problems significantly increase internal resistance (up to 20%-50% after vibration) and reduce discharge uniformity, thus impacting battery performance and lifespan. Traditional solutions, such as increasing Zn electrode thickness or using rigid current collectors, compromise battery energy density or flexibility. Researchers have conducted extensive research to suppress dendrite growth. Zn dendrite formation primarily stems from uneven distribution of the electric field and ion concentration on the Zn sheet surface. Therefore, uniformly depositing Zn onto a highly conductive porous three-dimensional framework current collector to create a three-dimensional porous Zn anode, which uniformizes the electric field strength and Zn ion concentration, is a highly effective strategy for suppressing dendrite growth. Three-dimensional porous carbon cloth, carbon nanotubes, graphene foam, zinc-philic three-dimensional metals and MXene have all been proven to be very effective zinc deposition framework materials.

[0003] Carbon nanotubes are nanotubes with radial dimensions of nanometers and axial dimensions of micrometers.

[0004] The tube is basically sealed at both ends and hollow. It is a one-dimensional quantum material with a special structure.

[0005] Dr. Iijima of a Japanese electronics company reported on the discovery of the structure of carbon nanotubes. Structurally, carbon nanotubes are closed tubes formed by the curling of graphite layers along a specific helical vector. A carbon tube consisting of only one graphite layer is called a single-walled carbon nanotube (SWCNT), while a coaxial tube formed by the curling of multiple graphite layers is called a multi-walled carbon nanotube (MWCNT). Experimentally observed single-walled carbon nanotubes typically have diameters between 0.6 and 2 nm. The innermost layer of a multi-walled carbon nanotube can be as small as 0.4 nm in diameter, while the outermost layer can reach diameters of tens to hundreds of nanometers. The integrity of its molecular structure gives carbon nanotubes unique electrical, mechanical, and chemical stability. Carbon nanotubes (CNTs), with their unique structure and excellent mechanical and electrochemical properties, are an advanced flexible energy storage material. They can be processed into conductive pastes and incorporated as conductive agents into positive and negative active materials, making them widely used in various electrode conductive pastes to improve battery performance. Furthermore, CNTs possess excellent toughness and a chemically tunable surface, making them easily processable into flexible films or paper. They also possess exceptional mechanical and electrical properties, making them suitable for use in a variety of flexible energy storage devices. Leveraging their excellent conductivity, superconducting composite flexible electrodes have been fabricated using multi-walled CNTs. The resulting flexible zinc-manganese battery generates a voltage capable of illuminating a light-emitting diode (LED). Experiments have demonstrated that multi-walled CNTs exhibit superior conductivity compared to graphite. Although carboxylation of CNTs improves their dispersion, it also increases electrode resistance, thereby reducing the battery's electrochemical performance.

[0006] Therefore, developing a negative electrode material with good vibration resistance that can reduce the increase in internal resistance of alkaline batteries during vibration has become an important direction of current research. Summary of the Invention

[0007] The present invention aims to provide a negative electrode material that reduces the increase in internal resistance of alkaline zinc-manganese dioxide batteries during vibration. By introducing carbon nanotubes and bismuth oxide into the negative electrode material, combined with a flexible binder, sodium polyacrylate, a three-dimensional conductive network is formed to inhibit dendrite growth, significantly reducing the increase in internal resistance caused by vibration.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0009] A negative electrode material for reducing the increase in internal resistance of an alkaline zinc-manganese battery during vibration comprises mercury-free zinc alloy powder, potassium hydroxide, deionized water, carbon nanotubes, bismuth oxide, sodium polyacrylate, and a betaine surfactant.

[0010] Furthermore, the negative electrode material is composed of the following components: mercury-free alloy zinc powder: 60-63 wt%, potassium hydroxide: 9-11 wt%, deionized water: 22-24 wt%, carbon nanotubes: 2-4 wt%, sodium polyacrylate: 0.5-1.5 wt%, bismuth oxide: 0.5-1.5 wt%, and betaine surfactant 0.04-0.06 wt%.

[0011] Preferably, the negative electrode material is composed of the following ingredients: mercury-free alloy zinc powder: 61.95wt%, potassium hydroxide: 10wt%, deionized water: 23wt%, carbon nanotubes: 3wt%, sodium polyacrylate: 1wt%, bismuth oxide: 1wt%, and betaine surfactant 0.05wt%.

[0012] Preferably, the carbon nanotubes are a combination of multi-walled carbon nanotubes and single-walled carbon nanotubes, and the ratio of the multi-walled carbon nanotubes to the single-walled carbon nanotubes is 1:1 to 3:1.

[0013] Preferably, the specifications of the multi-walled carbon nanotubes are: tube diameter 40-80 nm, tube length 10-25 μm.

[0014] Preferably, the specifications of the single-walled carbon nanotubes are: tube diameter 1.5-1.7 nm, tube length > 100 μm.

[0015] Preferably, the sodium polyacrylate is a dissolved sodium polyacrylate.

[0016] Preferably, the bismuth oxide is bismuth trioxide.

[0017] Preferably, the betaine surfactant is dodecylethoxysulfobetaine.

[0018] Preferably, the mercury-free zinc alloy powder consists of the following components: indium: 0.025-0.045 wt %, bismuth: 0.020-0.035 wt %, aluminum: 0.020-0.040 wt %, and the remaining component is zinc.

[0019] The present invention also provides a method for preparing a negative electrode material for reducing the increase in internal resistance of an alkaline zinc-manganese battery during vibration: first, potassium hydroxide is mixed with deionized water to obtain a solution; then, mercury-free alloy zinc powder, two carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are ball-milled and mixed; then, the potassium hydroxide solution is added for wet mixing treatment and vacuum degassing is performed to obtain the negative electrode material for the alkaline zinc-manganese battery.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Through the effective implementation of the present invention, carbon nanotubes are introduced into the zinc paste to form a three-dimensional conductive network; the in-situ reaction of bismuth trioxide and zinc forms a dense interface layer, inhibiting dendrite growth; combined with the flexible binder sodium polyacrylate, it absorbs vibration energy and can significantly reduce the increase in internal resistance of the battery caused by vibration. The open circuit voltage and internal resistance of the manufactured battery before and after vibration remain basically consistent.

[0022] 2. The raw materials of the present invention are sufficient in China and are reasonably priced, so that there is no high cost limit for large-scale production; at the same time, the aluminum alloy is simple and the overall production cost is not high, which is conducive to large-scale industrial production. DETAILED DESCRIPTION

[0023] In order to deepen the understanding of the present invention for those skilled in the art, the present invention will be further described below with reference to specific embodiments:

[0024] Example 1:

[0025] Weigh the specific materials according to Table 1.

[0026] Preparation method steps: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with the potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0027] Example 2:

[0028] Weigh the specific materials according to Table 1.

[0029] Preparation method steps: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with the potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0030] Example 3:

[0031] Weigh the specific materials according to Table 1.

[0032] Preparation method steps: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with the potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0033] Comparative Example 1:

[0034] Weigh the specific materials according to Table 1.

[0035] Preparation method: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free zinc alloy powder, single-walled carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0036] Comparative Example 2:

[0037] Weigh the specific materials according to Table 1.

[0038] Preparation method: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free zinc alloy powder, multi-walled carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0039] Comparative Example 3:

[0040] Weigh the specific materials according to Table 1.

[0041] Preparation method steps: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, bismuth trioxide, and dodecylethoxysulfobetaine are then ball-milled together. The mixture is then wet-mixed with the potassium hydroxide solution and vacuum-degassed to obtain an alkaline zinc-manganese battery anode material. This anode material is used in our company's production process to produce alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open-circuit voltage and internal resistance parameters before and after the test are shown in Table 2.

[0042] Comparative Example 4:

[0043] Weigh the specific materials according to Table 1.

[0044] Preparation method steps: Potassium hydroxide and deionized water are first mixed to obtain a solution. Mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, and dodecylethoxysulfobetaine are then ball-milled and mixed. The potassium hydroxide solution is then added for wet mixing and vacuum degassing to obtain an alkaline zinc-manganese battery negative electrode material. This negative electrode material is used in our company's production process to prepare alkaline zinc-manganese batteries. The batteries were vibration tested according to standard GB8897.5-2019. The open circuit voltage and internal resistance parameters of the batteries before and after the test are shown in Table 2.

[0045] Table 1 Material types

[0046]

[0047] Table 2 Battery open circuit voltage and internal resistance before and after vibration test

[0048]

[0049] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A negative electrode material for reducing the increase in internal resistance of an alkaline zinc-manganese battery during vibration, characterized in that: The negative electrode material is composed of the following ingredients: mercury-free alloy zinc powder: 60-63 wt%, potassium hydroxide: 9-11 wt%, deionized water: 22-24 wt%, carbon nanotubes: 2-4 wt%, sodium polyacrylate: 0.5-1.5 wt%, bismuth oxide: 0.5-1.5 wt%, and betaine surfactant: 0.04-0.06 wt%.

2. The negative electrode material according to claim 1, wherein the negative electrode material is composed of the following components: Mercury-free zinc powder: 61.95wt%, potassium hydroxide: 10wt%, deionized water: 23wt%, carbon nanotubes: 3wt%, sodium polyacrylate: 1wt%, bismuth oxide: 1wt%, betaine surfactant: 0.05wt%.

3. The negative electrode material according to claim 1, characterized in that The carbon nanotubes are a combination of multi-walled carbon nanotubes and single-walled carbon nanotubes, and the ratio of the multi-walled carbon nanotubes to the single-walled carbon nanotubes is 1:1 to 3:

1.

4. The negative electrode material according to claim 3, characterized in that The specifications of the multi-walled carbon nanotubes are: tube diameter 40-80 nm, tube length 10-25 μm.

5. The negative electrode material according to claim 3, characterized in that The specifications of the single-walled carbon nanotubes are: tube diameter 1.5-1.7 nm, tube length > 100 μm.

6. The negative electrode material according to claim 1, characterized in that The sodium polyacrylate is a dissolved sodium polyacrylate.

7. The negative electrode material according to claim 1, characterized in that The bismuth oxide is bismuth trioxide.

8. The negative electrode material according to claim 1, characterized in that The betaine surfactant is dodecylethoxysulfobetaine.

9. The negative electrode material according to claim 1, characterized in that The mercury-free zinc alloy powder is composed of the following components composition: Indium: 0.025~0.045wt%, bismuth: 0.020~0.035wt%, aluminum: 0.020~0.040wt%, and the remaining component is zinc.

10. A method for preparing the negative electrode material according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: firstly mixing potassium hydroxide and deionized water to obtain a solution; then ball-milling and mixing mercury-free alloy zinc powder, two types of carbon nanotubes, sodium polyacrylate, bismuth trioxide and dodecylethoxysulfobetaine; adding potassium hydroxide solution for wet mixing and performing vacuum degassing to obtain an alkaline zinc-manganese battery negative electrode material.

Images