CN1295813C

CN1295813C - Sealed zinc-air battery

Info

Publication number: CN1295813C
Application number: CNB2003101063086A
Authority: CN
Inventors: 蔡传禔
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-14
Filing date: 2003-11-14
Publication date: 2007-01-17
Anticipated expiration: 2023-11-14
Also published as: CN1617382A

Abstract

A sealed zinc-air battery is composed of positive and negative electrodes, the manganese dioxide in said zinc-manganese battery is replaced by oxygen in air, and the carbon electrode consisting of foam and active composition embedded in it, which is a mixture of activated carbon, graphite, beta-manganese dioxide and teflon emulsion. The negative electrode is zinc paste prepared by uniformly mixing zinc powder and sodium polyacrylate with a potassium hydroxide solution. The positive and negative electrodes can be processed into cylindrical or flat or sealed zinc-air battery with replaceable zinc negative electrode. The zinc-air battery can replace a zinc-manganese battery, has large capacitance, high utilization rate of the negative electrode, stable discharge and reliable performance, can be used independently and can also be used as a combined battery.

Description

Sealed zinc-air battery

1. Field of the invention

The invention relates to a primary battery in a chemical power supply, in particular to a sealed zinc-air battery.

2. Background of the invention

Lechanche (Lechanche) batteries, (also known as zinc manganese batteries, voltaic batteries, dry cell batteries, etc.) have been in the past for over 130 years. The main materials of the positive electrode of the neutral zinc-manganese battery (shown in fig. 2) and the alkaline zinc-manganese battery (shown in fig. 3) which are widely used at present are manganese dioxide, wherein the natural manganese dioxide is used as the former, and electrolytic manganese dioxide is used as the latter. Manganese is a precious mineral resource, and the manganese resource in China is not abundant and is gradually exhausted due to the inability of regeneration. In addition, the electrolytic manganese consumes a large amount of energy and water, and one ton of electrolytic manganese consumes at least 500kwh.

3. Summary of the invention

The zinc-air battery comprises a positive electrode and a negative electrode, and is characterized in that the positive electrode uses cheap oxygen in the air to replace expensive manganese dioxide. The technical scheme of introducing and fixing oxygen in the air into the positive electrode is to use a carbon electrode with a certain structure, namely, a foaming body is used as a carrier (framework), and an active composition is embedded into the foaming body to form the carbon electrode.

The foaming body can be alkali-resistant hard foaming plastic, such as foaming polyurethane, foaming polyvinyl formal and the like, and can also use metal which is stable in an alkali medium, such as foaming nickel, foaming iron, foaming magnesium and the like.

The active composition comprises the following components in percentage by weight (the same as below):

75 to 85 percent of active carbon

3 to 7 percent of graphite

3 to 7 percent of beta-manganese dioxide

8 to 12 percent of polytetrafluoroethylene emulsion.

The activated carbon and graphite with high specific surface area are both adsorbents and catalysts for half-reaction (reduction reaction). Beta-manganese dioxide has a catalytic action to increase the current density. The polytetrafluoroethylene emulsion acts as a binder.

The corresponding negative electrode uses 25-35% potassium hydroxide solution to prepare the composition mainly containing zinc powder into paste, also called zinc paste. The zinc powder composition comprises 96-98% of zinc powder and 2-4% of sodium polyacrylate. The zinc powder is the raw material of the other half reaction (oxidation reaction), and the sodium polyacrylate plays a role in moisturizing and preventing the zinc paste from being dehydrated, dried and agglomerated.

The positive electrode and the negative electrode can be used for processing a zinc-air battery, and the shape of the battery can be determined according to the requirements of the application occasions, such as a cylindrical shape, a flat shape and the like. In addition, the zinc-air battery can be processed into a movable zinc-air battery with a replaceable zinc cathode. The zinc-air battery is coated with a polytetrafluoroethylene film, so that the battery is ensured to be free from liquid leakage completely.

The indexes of the zinc-air battery are shown in the following table, and a neutral zinc-manganese battery (loose R20) and an alkaline zinc-manganese battery (south floating R20) are used as comparison.

Product(s) Name (R)	Weight (D) (gram)	Open circuit Press (V)	Short circuit electricity Flow (A)	Constant resistance continuous discharge time (minutes)			Total discharge Capacity of (Ah)	Total discharge (Energy) (Wh)	Weight ratio of (Energy) Wh/Kg	Negative electrode Zinc alloy Rate of utilization (％) **
				Constant resistance continuous discharge time (minutes)							1Ω	3.9Ω	Total time of day Workshop
				Zinc hollow Battery with a battery cell	65	1.4					1Ω	3.9Ω	Total time of day Workshop	6	536	1189	1725	14.14	14.5	22.3	74
Loose stool R20	95	1.6	7	Zinc hollow Battery with a battery cell	65	1.4	27	274	301	1.63	1.68	17.68	14.2	6	536	1189	1725	14.14	14.5	22.3	74
Loose stool R20	95	1.6	7	Nanfu LR20	134	1.6	27	274	301	1.63	1.68	17.68	14.2	6	420	1103	1523	11.45	11.25	84	50

* Note: the battery is discharged to 0.85V by 1 omega continuously and then discharged to 0.9V by 3.9 omega

* Injecting: is the utilization rate under the control of the intrinsic discharge

The zinc-air battery can replace a zinc-manganese battery, has simple manufacturing process, extremely balanced discharge, large electric capacity, high utilization rate of the negative electrode, stable and reliable performance and the same size as a large number of common batteries. Can be used alone or as a combined battery, and is a small standby power supply. In particular to a big problem of alkaline zinc-manganese battery leakage.

4. Description of the drawings

Fig. 1 is a schematic diagram of the structure of a neutral zinc-manganese battery. 1 is a zinc shell (a cathode also serves as a container), 2 is a cathode reactant, and NH ₄ Cl、ZnCl ₂ 、MnO ₂ The paste 3 is a positive electrode lead-out material, which is a carbon rod, and one end of the carbon rod is covered by a metal cover.

Fig. 2 is a schematic diagram of an alkaline zinc-manganese battery. 1 is steel shell (also used as anode leading out), 2 is MnO ₂ Ring (positive electrode reactant), 3 is a zinc paste (negative electrode reactant), and 4 is a negative electrode lead-out.

Fig. 3 is a schematic structural diagram of the present invention.

5. Detailed description of the preferred embodiments

The non-limiting examples, with foamed nickel as the carrier, are described below:

1. preparation of the positive electrode: 75g of activated carbon (hereinafter referred to as A), 6g of graphite (hereinafter referred to as B), 7g of beta-manganese dioxide (hereinafter referred to as C) and 12g of polytetrafluoroethylene emulsion (hereinafter referred to as D), or 85g of A, 4g of B, 3g of C and 8g of D, or 5g of A, 80g of B and 10g of C respectively are uniformly mixed to obtain an active composition, and the active composition is coated on foamed nickel to obtain the positive electrode capable of adsorbing and fixing oxygen in air.

2. Preparation of a negative electrode: 96g of zinc powder and 4g of sodium polyacrylate are uniformly mixed or respectively 95g and 5g or respectively 98g and 2g are uniformly mixed, and then the mixture is prepared into paste by using 25-35% of potassium hydroxide solution and preferably 30% of potassium hydroxide solution, thus obtaining the zinc paste cathode.

3. And (5) processing the battery.

As shown in fig. 1a, the battery is cylindrical and has the same size as a zinc-manganese large-size battery. The carbon electrode processed by the method is rolled into a cylinder 1 (the shell wall and the anode are led out), a polytetrafluoroethylene film is coated outside the cylinder, a plastic bottom cover is sealed, zinc paste 2 is filled inside the cylinder, a zinc rod 3 is arranged in the cylinder to be used as the cathode to be led out, and a plastic end cover is sealed.

As shown in fig. 1b, the zinc negative electrode is replaceable in a flat plate shape. The box body 1 and the matched detachable upper cover 4 are made of plastic or stainless steel. The box body 1 is filled with

zinc paste

2,3 as a negative electrode lead wire. The upper cover 4 is provided with a vent hole 5, the inner side of the upper cover 4 is fixed with a carbon electrode 6 (anode), and 7 is an anode lead-out wire. The zinc cream 2 can be replaced by detaching the upper cover 4.

Claims

1. A sealed zinc-air battery comprises a positive electrode and a negative electrode, and is characterized in that: the method is characterized in that oxygen in air adsorbed in a carbon electrode is used as a positive electrode, an active composition is embedded in a foam carrier of the carbon electrode, and the active composition is a mixture consisting of the following raw materials in percentage by weight: 75-85% of active carbon, 3-7% of graphite, 3-7% of beta-manganese dioxide and 8-12% of polytetrafluoroethylene emulsion; the negative electrode is zinc powder with 96-98% and sodium polyacrylate with 2-4% and potassium hydroxide solution with 25-35% to prepare uniform zinc paste.

2. The sealed zinc-air battery according to claim 1, wherein: the foaming carrier is foaming nickel.

3. The sealed zinc-air battery according to claim 1 or 2, characterized in that: the active composition is a mixture consisting of 80% of active carbon, 5% of graphite, 5% of beta-manganese dioxide and 10% of polytetrafluoroethylene emulsion; the negative electrode is prepared by mixing 98 percent of zinc powder and 2 percent of sodium polyacrylate with 30 percent of potassium hydroxide solution to prepare uniform zinc paste.