Analysis of the structure and use of lead-acid batteries

Lead-acid batteries generally consist of 3 or 6 single cells connected in series, consisting of plates, separators, electrolyte, casing, poles and filling plugs (no maintenance-free batteries). Lead-acid battery 1. The polar plate of a lead-acid battery is divided into a positive plate and a negative plate, both of which are composed of a grid and an active material. The purpose of the grid. Elevators have side effects, which can accelerate the precipitation of hydrogen and accelerate the consumption of electrolyte. It is also easy to introduce from the positive grid to cause self-discharge of the battery and corrosion of the grid, which shortens the service life of the battery. At present, low brocade alloy grids (with ladder content of 2%-3.5%) or lead-calcium alloys are mostly used at home and abroad. The active material on the positive plate is lead dioxide (Pb02), which is dark brown; the active material on the negative plate is spongy pure lead (Pb), which is blue-gray. The active material is adjusted into a paste and filled in the gaps of the grid and dried to form an electrode plate. Immerse each of the positive and negative plates in the electrolyte to obtain an electromotive force of about 2V. In order to increase the capacity of the battery, multiple positive and negative plates are often connected in parallel to form a group of positive and negative plates, as shown in the picture (drawing). In each single cell battery, the number of positive plates is one less than that of the negative plates, so that each positive plate is located between the two negative plates, which can make the discharge of both sides of the positive plate even, and beware of the uneven discharge. Board arch. 2. The separator of the lead-acid battery is inserted between the positive and negative plates, and its purpose is to prevent the positive and negative plates from contacting each other to cause a short circuit. The separator should be acid resistant and porous to facilitate the penetration of the electrolyte. Commonly used separator materials include wood, microporous rubber, and microporous plastics. Among them, wooden partitions have poor acid resistance and have been eliminated. Microporous rubber separators have the best performance but higher cost. Microporous plastic separators have small pore size, high porosity, and low cost, so they are widely used. During installation, the side with grooves should face the positive plate and be perpendicular to the bottom of the case. At the same time, the grooves can dredge the electrolyte up and down so that bubbles can rise along the grooves. The microporous plastic can be made into a bagged separator. Put it on the positive plate to prevent the active material from falling off. 3. Electrolyte Electrolyte plays the role of ionic conduction in the chemical reaction of lead-acid batteries, and participates in the chemical reaction of the battery. The electrolyte is made up of pure sulfuric acid (H:S0.) and distilled water in a certain ratio, and its density is generally 1.24~1.30g/cm'. Choose electrolyte density according to season and region. The liquid level should be 10-15mm higher than the upper plane of the plate (separator). 4. The shell of the lead-acid battery The shell is used to hold the discharge solution and the plate assembly, and should be acid-resistant, heat-resistant, and shock-resistant. The shell is mostly made of hard rubber or polypropylene plastic and has an integral structure, with raised ribs on the bottom to hold the plate assembly. The inside of the shell is divided into 3 or 6 cells that are not connected to each other by the partition wall, and the cells are connected in series with lead tie bars (pictured). The upper part of the casing is sealed with a battery cover of the same material. The battery cover is provided with a filling hole corresponding to each single cell for adding electrolyte and distilled water, and measuring electrolyte density, temperature and liquid level. The ventilation hole on the filling hole cover can smoothly discharge the gas that appears in the chemical reaction of the battery. Strips: The purpose of strips is to connect single-cell storage cells in series to increase the terminal voltage of the middle battery. 5. Lead-acid battery poles: general battery terminals are welded on the horizontal plates of the first and last two-electrode plate groups There are three types of terminal side control type, conical and I-shaped. In order to facilitate the difference, the positive terminal is marked with a + or p mark, some terminals are painted with red paint, and the negative terminal is marked with a-or N mark. When it is unclear, it can be measured with a voltmeter. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of the cathode material of the ternary lithium battery