CN104269560A

CN104269560A - High-energy zinc-manganese battery

Info

Publication number: CN104269560A
Application number: CN201410457207.1A
Authority: CN
Inventors: 孙晓刚; 庞志鹏; 吴小勇; 付琦; 程晓圆
Original assignee: Nanchang University
Current assignee: Nanchang University
Priority date: 2014-09-10
Filing date: 2014-09-10
Publication date: 2015-01-07

Abstract

A high-energy Zn-Mn battery is composed of steel casing, positive electrode ring, zinc paste, isolating paper, sealing ring, copper nails and negative electrode cover, and features that a layer of electrically conducting carbon nanotube paper is additionally used as the current collector of positive electrode between steel casing and positive electrode ring. The zinc-manganese battery has the following advantages: firstly, the affinity of the anode material and the current collector is increased, and compared with a steel shell, the contact is tighter, so that electrons can be well converged on the carbon nanotube conductive paper; secondly, the carbon nano tube has stronger liquid absorption property, can well store electrolyte, and stores more electrolyte in the zinc-manganese battery, so that the reaction can be continuously carried out.

Description

High-energy zinc-manganese battery

Technical Field

The invention belongs to the technical field of batteries.

Background

With the advent of the electronic age, more and more electronic products, such as cameras, flashlights, calculators, electric toys, and the like, are required to continuously discharge large current and have high energy. Common carbon batteries and difficulty in meeting capacity requirements; the lithium ion battery uses organic electrolyte to generate inflammable and explosive accidents, and is expensive; the zinc-nickel battery is also very expensive due to the lack of nickel resources.

The alkaline zinc-manganese battery has reasonable structural design, can be produced in large scale, has excellent electrochemical performance and higher cost performance, has 4-5 times of electric capacity compared with the common carbon battery, and is low in price and applied in large scale.

With the increase of the demand of people, the general alkaline zinc-manganese battery is more and more difficult to meet the energy requirement of electronic products. Since the alkaline zinc-manganese battery is a standard cylindrical battery, has a standard size, the diameter and height of the battery are constant, and the mass increase of the active material is limited, it is necessary to sufficiently improve the utilization rate of the active material and output more electric energy.

The positive electrode of the alkaline zinc-manganese battery is mainly manganese dioxide (MnO 2), graphite, and a proper amount of binder-polytetrafluoroethylene wax micropowder and electrolyte are added, dispersed, stirred uniformly, tableted, granulated and looped to form an annular structure, and the negative electrode is mainly prepared from zinc paste, water-absorbing polymer and KOH electrolyte. The negative electrode of the alkaline zinc-manganese battery is made of zinc paste prepared by adding about 38% KOH strong base into fine zinc alloy powder and water-soluble polyvinyl acid.

Electrochemical expression of alkaline zinc manganese cell:

and (3) battery reaction:

negative electrode:

and (3) positive electrode:

the general reaction formula is as follows:

the positive current collector of the alkaline zinc-manganese battery is generally a steel shell outside the battery, and the negative electrode is generally a copper nail at the bottom. As the main material of the anode is MnO ₂ ，MnO ₂ The affinity with the steel shell is poor, and the positive current collector is adhered to the positive current collector through a binder and cannot be perfectly combined together. The positive reaction product is MnOOH, and the structure is layered and loose. It is difficult for electrons to maintain smooth ion channels in the MnOOH layer in the late stage of discharge.

The carbon nano tube as a nano material has excellent physical and chemical properties, particularly the electric conductivity of the carbon nano tube is close to that of a superconductor, and the carbon nano tube can be an excellent electric conduction material. At present, carbon nanotubes are added in most lithium ion batteries as a conductive agent, and the application of the carbon nanotubes is basically not involved in zinc-manganese batteries. After the carbon nano tube and the paper fiber are compounded, the excellent conductivity of the carbon nano tube is macroscopically displayed, and the compounded conductive paper also keeps the good flexibility of the paper, so that the application value of the paper is doubled.

Disclosure of Invention

The invention aims to solve the problems of low utilization rate of the positive electrode material, unsmooth electron transfer, short service time and low specific energy of a battery caused by the fact that the positive electrode material is not tightly combined with a steel shell current collector when discharging at medium and small current under the condition of not increasing the positive electrode material. The positive current collector has longer discharge time and higher initial voltage under the condition of continuous discharge of medium and small currents, and greatly improves the discharge performance of the battery.

The technical scheme adopted by the invention for solving the technical problem is as follows.

The utility model provides a high energy zinc-manganese dioxide battery, includes box hat (1), anodal ring (3), calamine cream (4), diaphragm paper (5), sealing washer (6), copper nail (7) and negative pole lid (8), its characterized in that increases one deck carbon nanotube electrically conductive paper (2) between box hat (1) and anodal ring (3) and regards as anodal mass flow body, increases the affinity of anodal material and mass flow body, guarantees smooth the assembling and the conduction of electron, increases anodal material's utilization ratio by a wide margin, obtains high energy alkaline zinc-manganese dioxide battery.

The carbon nano tube conductive paper is formed by compounding paper pulp fibers and carbon nano tubes and is formed by a paper making method. Specifically, the preparation method of the carbon nanotube paper comprises the following steps: heat-treating carbon nanotubes in a microwave oven for 5-10 min, chemically purifying and surface-modifying, adding the carbon nanotubes into distilled water, ethanol or acetone solvent, and dispersing to disperse the carbon nanotubes in the liquid; stirring and mixing the carbon nano tube solution and the paper pulp, and then fully and uniformly dispersing the carbon nano tube and the paper pulp by using a high-speed shearing emulsifying machine; the carbon nanotube conductive paper is manufactured by adopting a common papermaking method, and is compacted by a hydraulic press after vacuum drying, so that the carbon nanotube conductive paper is prepared.

The content of the carbon nanotubes in the carbon nanotube conductive paper is 20-80%.

The thickness of the carbon nanotube conductive paper is 0.1mm to 0.8mm.

The preparation method of the high-energy zinc-manganese battery comprises the following steps: the carbon nanotube paper (2) is curled and sleeved into a battery steel shell, the anode ring (3) is pressed into the inner ring of the carbon nanotube paper (2), a diaphragm paper (5) cylinder is inserted, electrolyte is injected into the diaphragm paper (5) cylinder, zinc paste (4) is injected after the electrolyte is completely soaked, a copper nail (7) with a cathode cover (8) is inserted, and the battery is obtained by pressing and sealing.

The zinc-manganese battery has the following advantages: firstly, the affinity of the anode material and the current collector is increased, and the contact is tighter compared with a steel shell, so that electrons can be well converged on the carbon nanotube conductive paper; secondly, the carbon nano tube has stronger liquid absorption property, can well store electrolyte, and stores more electrolyte in the zinc-manganese battery, so that the reaction can be continuously carried out.

Drawings

FIG. 1 is a schematic view of the structure of the present invention. Wherein, 1 is a steel shell, 2 is carbon nano tube conductive paper, 3 is an anode ring, 4 is zinc paste, 5 is diaphragm paper, 6 is a sealing ring, 7 is a copper nail, and 8 is a cathode cover.

FIG. 2 is a photograph of the carbon nanotube conductive paper of the present invention.

Fig. 3 is an SEM image of carbon nanotube conductive paper.

Fig. 4 is a comparison of discharge diagrams of the flexible zinc-manganese dioxide battery respectively using the graphite sheet and the carbon nanotube conductive paper as positive electrode current collectors.

Detailed Description

The invention will be further explained by the following embodiments in conjunction with the accompanying drawings.

As shown in fig. 1, the high-energy zinc-manganese battery comprises a steel shell 1, carbon nanotube conductive paper 2, a positive electrode ring 3, zinc paste 4, diaphragm paper 5, a sealing ring 6, a copper nail 7 and a negative electrode cover 8.

According to the invention, a layer of carbon nanotube conductive paper 2 is added between the steel shell 1 and the anode ring 3 to serve as a current collector of the anode, so that the utilization rate of the anode material of the battery is improved, and the discharge time of the zinc-manganese battery is greatly prolonged.

Manufacturing the carbon nano tube conductive paper:

taking 2g of carbon nano tube, carrying out heat treatment in a microwave oven for 5 minutes, carrying out chemical purification and surface modification, adding the carbon nano tube into 100ml of distilled water, carrying out electric ultrasonic treatment and mechanical ultrasonic treatment for 1 hour respectively, and then carrying out dispersion treatment by adopting a high-speed shearing machine to uniformly disperse the carbon nano tube in liquid.

Adding 2g of regenerated paper pulp into 500mL of distilled water, fully and uniformly stirring the paper pulp for 3h by adopting a high-speed shearing emulsifying machine, adding the paper pulp into the dispersed carbon nano tube dispersion liquid, and shearing and dispersing by adopting the high-speed shearing emulsifying machine.

The carbon nano tube and the pulp fiber are uniformly deposited on the filter paper by adopting a vacuum filtration method, and the carbon nano tube and the pulp fiber are repeatedly rolled into conductive paper with the thickness of 0.5mm after being dried for 12 hours at 50 ℃.

In this example, the carbon nanotubes produced by lithium battery of Nanchang university and research institute of New energy automobile were used as the material for preparing the conductive paper.

And (3) comparing experimental data: fig. 4 shows that, under the same condition of the positive electrode material, the discharge time of the flexible zinc-manganese battery positive electrode current collector made of the carbon nanotube conductive paper is increased from 10 hours to 29 hours compared with the discharge time of the flexible zinc-manganese battery positive electrode current collector made of the graphite sheet, and a stable discharge platform appears in the process of 3-25 hours. Because the quality of the anode material and the cathode material is the same, the cathode zinc sheet is not consumed after the reaction is finished, and the quality of the anode material is obviously reduced, the conclusion is drawn that the anode manganese dioxide is fully reacted when the carbon nano tube conductive paper is used as the current collector, and the discharge time of the battery is greatly prolonged.

Claims

1. A high-energy Zn-Mn battery is composed of steel casing, positive electrode ring, zinc paste, isolating paper, sealing ring, copper nail and negative electrode cover, and features that a layer of electrically conducting carbon nanotube paper is additionally used as the current collector of positive electrode between steel casing and positive electrode ring.

2. The high energy zn-mn cell according to claim 1, wherein the carbon nanotube conductive paper is a paper made by combining paper pulp fibers and carbon nanotubes and performing a paper-making process.

3. The high energy zinc-manganese dioxide cell of claim 1, wherein the carbon nanotube content in said carbon nanotube conductive paper is 20% to 80%.

4. The high-energy alkaline zinc-manganese dioxide battery as claimed in claim 1, wherein the thickness of the carbon nanotube conductive paper is 0.1mm to 0.8mm.