Advantages and types of new batteries
As far as the current market is concerned, the main types of new batteries are: maintenance-free batteries, dry-type charged lead batteries, gel electrolyte batteries and alkaline batteries. Their specific advantages and structural characteristics are as follows:
1. Maintenance-free storage battery
1. Structural material characteristics
①Pool shell It is equipped with a gas collecting chamber to collect water vapor or sulfuric acid vapor and condense and recover it to avoid evaporation of water and sulfuric acid.
②The thin-walled polypropylene shell, with the bottom ribs, reduces the dimension of the plate, and can increase the upper liquid storage.
③The bag-type microporous polyvinyl chloride partition prevents the active material from falling off.
④The grid frame is made of lead-calcium-tin alloy or lead-low-selling (2%-3% antimony) to eliminate or reduce the side effects of brocade.
⑤ Built-in temperature compensation type density meter, easy to monitor the power storage and liquid level. When the surface of the densitometer indicator is green, it indicates that the battery is fully charged; when the green area is small or black, it needs to be recharged; when it is yellow, it indicates that the liquid level is too low and the battery can no longer be used, and the shell should be checked for cracks .
2. Advantages of maintenance-free batteries
①Under the specified conditions, there is no need to add distilled water during use (the time can reach three or four years, and the mileage can reach: city District 80,000 kilometers, long-distance 400-480,000 kilometers).
② Less self-discharge, only 1/6-1/8 of ordinary batteries. Therefore, it can be stored wet within two years.
③Small internal resistance, higher discharge voltage and better starting performance at room temperature and low temperature. ④Good overcharge resistance. Under the same conditions, the overcharge current is small, and it can be close to zero after being fully charged, that is, basically no water is electrolyzed.
⑤The pole is non-corrosive or corroded very lightly.
⑥Good heat resistance and vibration resistance, and long service life (the service life is generally four years, which is more than twice that of ordinary batteries).
Second, dry-type charged lead storage battery
(The plate can be used for a long time in a completely dry state—generally the amount of electricity obtained in the process of storage for 2 years)
1. Advantages of dry-charged batteries
Its working principle and characteristics are the same as ordinary batteries, but the manufacturing process is different. It is a dry-sealed charged battery. The new battery can be used after adding enough electrolyte according to the regulations and standing for 20-30 minutes without initial charging; its storage period is 1 year longer than that of ordinary batteries.
2. The characteristics of the materials and manufacturing process of dry-charged batteries
①In the lead paste of the negative plate, an appropriate amount of rosin, oleic acid, fatty acid and other antioxidants are added to make each grain There is a protective film on the surface of the active material to improve water repellency and prevent lead oxidation.
②In the formation of plates, the formation time should be appropriately extended or repeated charging and discharging deepening methods can be used to maximize the conversion of active materials.
③After the negative plate is formed, it needs to undergo strict water washing and immersion to remove the sulfuric acid remaining on the negative plate to prevent the spongy lead from vulcanizing and drying after storage period 're-moisture'.
④Strictly dry the negative plate. The resistance of a single cell is less than 5000Ω.
3. Gel electrolyte battery
1. Concept: In the gel electrolyte battery, the electrolyte is a thick colloidal substance formed by mixing purified sodium silicate solution and sulfuric acid aqueous solution. .
2. Advantages: the electrolyte will not spill; the active material is not easy to fall off during maintenance and transportation; the service life can be extended by 20%; there is no need to adjust the density during use, just add distilled water.
3. Disadvantages: The resistance of the colloidal electrolyte is large, the internal resistance increases, and the capacity decreases; the contact with the electrode plate is uneven, and the self-discharge is more serious.
Four. Alkaline storage battery
1. Features: It has the advantages of light weight, long service life and less self-discharge. However, the conductivity of the active material of the alkaline storage battery is poor, and the price is relatively high.
2. Composition: Alkaline storage batteries use potassium hydroxide KOH aqueous solution or sodium hydroxide NaOH aqueous solution as electrolyte. Among them, KOH aqueous solution is the most widely used electrolyte.
3. Type: Typical representatives of alkaline batteries are nickel-iron batteries, nickel-cadmium batteries, zinc-silver batteries and so on. Only the commonly used iron-nickel batteries are introduced below.
(1) Nickel-iron battery
①The box-type iron-nickel battery with plate is composed of positive plate group, negative plate group and separator It is arranged in staggered form to form a pole plate group, which is put into the shell and is formed by sealing the bottom.
②The sintered iron-nickel battery is formed by staggered arrangement of positive plate group and negative plate group, which are packed into the shell and covered by coating. The positive electrode plate group and the negative electrode plate group are respectively formed by impregnating sintered polar plates.
2) Working principle
The battery electrolyte is an aqueous solution of KOH. It only conducts current, and the concentration is basically unchanged, so the degree of charging and discharging of the battery cannot be judged according to the density of the electrolyte. In the charged state, the active material on the positive plate is nickel hydroxide Ni(OH)3, and the negative plate is metallic iron Fe. When the discharge is terminated, the active material of the positive plate is converted into nickel hydroxide Ni(OH)2, and the active material of the negative plate is converted into ferrous hydroxide Fe(OH)2. The chemical reaction of the iron-nickel battery during charging and discharging is based on the valence
3) Performance : For the specific capacity of the nickel-iron battery (the ratio of power to mass), the plate-type battery is generally 30W.h/kg, and the sintered battery is 65W-h/kg; for the service life of the battery, the plate-type battery The heavy load working time is 8 years, and the cycle times of the sintered battery have exceeded 1000 times.