What Is a Zinc-Air Battery?

A zinc air battery is a primary battery that uses activated carbon to adsorb oxygen or pure oxygen in the air as a positive electrode active material, uses zinc as a negative electrode, and uses ammonium chloride or a caustic solution as an electrolyte. Also called zinc-oxygen battery. Zinc-air batteries divided into two systems, neutral and alkaline, are represented by the letters A and P, respectively, followed by the battery model.

Zinc air battery

Zinc air battery, which uses activated carbon to adsorb oxygen or pure oxygen in the air as the positive electrode active material, zinc as the negative electrode, and ammonium chloride or caustic solution as the electrolyte.

The charging process of zinc air batteries is very slow. In order to solve this problem, usually the anode zinc plate or zinc particles of zinc air batteries are oxidized to zinc oxide and fail. Generally, the zinc plate or zinc particles and electrolyte are directly replaced. Method to make the zinc air battery completely renewed. The chemical equations of the positive, negative and total reactions during discharge are:

2Zn + O2 + 2H2O = 2Zn (OH) 2

The pasty zinc powder is at the anode end, and the catalytic carbon is at the cathode. Holes in the battery case allow oxygen in the air to enter the cavity and attach to the carbon on the cathode. At the same time, the anode's zinc is oxidized, similar to the chemical reaction of a small silver-oxygen or mercury-oxygen battery.

Cathode-is the catalytic carbon that absorbs oxygen from the air.

Anode-yes

There are four main types. Neutral zinc-air battery: similar in structure to the zinc-manganese cylindrical battery, also using chlorine

Anode: Zn + 2OH ZnO + H ₂ O + 2e

Cathode: O ₂ + 2H ₂ O + 4e 4OH

Synthesis: 2Zn + O ₂ 2ZnO

Usually the voltage generated by this reaction is 1.4 volts, but the discharge current and discharge depth can cause voltage changes. Air must be able to enter the cathode without interruption, and there must be small holes in the cathode casing for the continuous inflow of oxygen to make the battery produce.

The key to zinc zinc battery storage is the seal. The battery cathode seal cannot be removed unless the battery is ready for immediate use. The simulation test shows that at room temperature, the electricity capacity drops to 95% after one year of storage, to 90% after two years of storage, and 85% after four years of storage. After removing the seal, the battery is activated and starts to work. When the room temperature environment is not connected to the load, according to different battery size specifications, the battery power decreases by 50% after 3 to 12 weeks, and decreases to 0-10% after 20 weeks. Therefore, the zinc air battery is suitable for the occasion where the battery is exhausted in a few weeks. If the seal of the zinc-air battery is torn off, the air will enter the interior to activate the electrochemical reaction. At this time, even if the seal is affixed again, the electrochemical reaction will continue until the power is exhausted.

In 1878, French L. Mechet

Principle The electrochemical reaction of a zinc-air battery is as follows:

In neutral solution: 2Zn + 4NH4Cl + O2 2Zn (NH3) 2Cl2 + 2H2O

In alkaline solution: 2Zn + 2NaOH + O2 2NaHZnO2

Performance characteristics and uses The voltage of the zinc-air battery is about 1.4V, and the discharge current is limited by the rate of oxygen adsorption and diffusion by the activated carbon electrode. Each type of battery has its optimal current value. When the limit value is exceeded, the activated carbon electrode will deteriorate rapidly. The charge capacity of a battery is generally more than three times larger than a zinc-manganese battery of the same volume. The charge of large zinc-air batteries is generally 500-2000Ah, which is mainly used for railway and marine beacon devices. Button-shaped zinc air batteries have a charge of 200-400mAh and have been widely used in hearing aids.

Q: Why are there seals on the back of zinc empty batteries?

The key to zinc zinc battery storage is the seal. You cannot remove the positive battery seal unless the battery is ready for immediate use.

Q: Will zinc air leak? What Hazards Will Leak?

Due to the high concentration of electrolyte (KOH, strong alkali **, strong corrosion **) inside the zinc air battery. ^[2]

Zinc air batteries contain a high concentration of electrolyte (potassium hydroxide, which is strongly alkaline and highly corrosive). Once a leak occurs, it will corrode parts near the battery, and this corrosion may be irreparable and fatal. Moreover, the battery has holes, and the storage time of the battery is very short after activation. Therefore, the zinc empty battery is more prone to battery leakage. When using a zinc-air battery, replace the exhausted battery in time, check the battery status frequently, and remove the battery when it is not used for a long time.