Valve-controlled sealed lead-acid accumulator for electric vehicle

Abstract

The invention relates to a design and manufacture method of valve-controlled sealed lead-acid accumulator for electric vehicle with high specific energy and deep cycle and long service life, wherein by the modification of a battery cover structure, the changes of charging/discharging state and temperature are monitored in real time for every 2V single battery of 4-24V of the whole accumulator; the positive and negative columns of the single battery are made of metal inserts; metal plates are connected between the metal inserts; the inserts and metal plates are all made of copper, aluminum and nickel and the like with densities less than the density of lead and conductivities better than the conductivity of lead; the surfaces of the inserts and the metal plates are all coated with lead, tin-lead or tin-lead-sliver alloy; the positive and negative pole plates are both thin pole plates; and 0.1%-2% of silica powder with an average grain diameter of 3-15 microns, 0.02%-0.5% of lignin and 0.5%-1.5% of conductive graphite are added in active substances which are diachylon; the use ratio of the active substances is greatly improved; ultra-fine glass fiber clapboards and a polyethylene (PE) clapboard are combined; and the accumulator in the invention is ensured to have the characteristics of high energy-density and deep cycle and long life.

Description

technical field [0001] The invention relates to a design and manufacture method of a high specific energy deep cycle long-life valve-regulated sealed lead-acid battery for an electric vehicle, especially for the charging and discharging state of each 2V single battery of a 4-24V integral battery and the change performance of temperature. Carry out timely monitoring. Background technique [0002] At present, my country is piloting the promotion of the use of new energy electric vehicles. It greatly promotes the research and development of batteries. New energy electric vehicles require batteries to have a large capacity—satisfied with long mileage, high power—satisfied with fast startup acceleration, strong climbing ability, short charging time—fast energy replenishment, convenient monitoring and maintenance And deep cycle long life, the performance of lead-acid batteries must fully meet these requirements, has become the biggest problem in the research and development of ne...

AI Technical Summary

Problems solved by technology

In the normal charging state, the internal pressure of the battery is too high, and the control valve is opened to discharge the gas. This gas usually carries sulfuric acid mist, which is directly discharged from the gap around the small cover on the battery cover, causing environmental pollution and equipment corrosion.

If the valve is in the open state of the exhaust, the external open flame is easy to detonate the battery, causing damage to equipment or personnel

[0006]This kind of old-fashioned valve-regulated sealed battery generally uses thick plates, and the capacity is calculated at a rate of 10 hours. The utilization rate of active materials is very low, greater than 0.2C When the current of 10A is discharged, its discharge performance is extremely poor, and it is very difficult to meet the requirements of the QC / T 742-2006 lead-acid battery standard for electric vehicles

One of the main reasons for the low utilization rate of the active material is that when the positive plate is discharging, the small holes inside the positive plate are blocked by the generated insoluble lead sulfate crystals, and the sulfuric acid needed to replenish the discharge inside the positive plate is hindered. It is difficult to continue the discharge between the plates

Especially when discharging at a high rate, the inside of the positive plate needs to be quickly replenished with sulfuric acid, which makes it difficult to achieve the purpose

[0007]In order to increase the porosity inside the active material of the positive plate, some people add conductive graphite, expanded graphite or carbon powder and other pore-forming agents to the lead paste used in the positive plate. Or increase the amount of sulfuric acid in the lead paste used in the positive plate. These methods can certainly increase the initial capacity of the battery and improve the early high-rate discharge performance of the battery, but due to the cyclic charge and discharge process, the positive lead paste additive mainly based on carbon is easy to Oxidized into carbon dioxide and gradually lost, resulting in softening of the positive active material and shortening the service life of the battery

The sulfuric acid content in the positive lead paste increases, although it can increase the porosity of the positive electrode active material to improve the high-rate discharge performance, but in the manufacturing process of the lead paste, the sulfuric acid content increases, the acidity of the lead paste increases, and the curing process of the plate In this process, the difficulty of oxidation of free lead is increased, resulting in an increase in the content of free lead in the green plate, which is difficult to form into the green plate, and it will affect the discharge performance of the cooked plate

[0008]In order to improve the high-rate discharge performance of the battery, thin plates are generally used to reduce the thickness of the plates and increase the number of positive and negative plates. Therefore, The distance between the positive and negative plates is greatly shortened. The glass fiber separators currently used mainly have ultra-fine glass fibers with large apertures. During the deep discharge cycle, the dendrites of the negative plates elongate and penetrate the separators. , It is easy to cause a short circuit and shorten the life of the battery

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