- Rational use of additives
From the chemical reaction equation, it can be seen that PbO2, Pb and H2SO4 are the necessary substances to really participate in the reaction in the battery charge and discharge reaction. Now there are all kinds of additives in the market, which only play an auxiliary role. Through the role of some components in the additives, the battery charge and discharge is easy, so it shows the characteristic of “increasing the battery capacity”; Some components prevent electro-hydraulic stratification, which shows the characteristics of “reducing corrosion” and “prolonging battery life”; Some components reduce the dissolution of brocade components in the plate, which shows the characteristics of “reducing self discharge”. The efficacy of these additives can only be brought into play under certain conditions, and none of them is effective under all use conditions.
Therefore, when using these additives, we must make clear the nature, dosage and use conditions of the additives, otherwise it will be counterproductive. It is common to damage the battery by blindly using additives. At present, there are many vulcanization additives in the market. The basic principle is that adding some alkali metals, under the action of charging current, alkali metal ions will enrich at the negative plate and form an alkaline environment in a local small range. Lead sulfate has great solubility in alkaline solution. When a part of lead sulfate is dissolved, the fresh Pb interface is exposed and charging can be carried out. At the same time, alkali metal ions will also replace part of lead sulfate, arrange dense lead sulfate on the electrode plate, open the gap on the surface, and expose the fresh Pb interface, making it easy to charge and achieve the purpose of de vulcanization.
This process method is only effective for the battery with negative plate vulcanization. It can never “bring back the dead” to all batteries, nor can it prolong the service life of the battery too much. This is because all the additives except vulcanization have the side effect of softening the plate, which will accelerate the attenuation of capacity after exceeding a certain amount.
- Misunderstanding of “maintenance free battery”
The technical development of lead-acid battery has experienced about 150 years. With the progress of technology, the performance of the battery is getting better and better. Especially after the birth of valve regulated battery, it has brought many convenience to users (we also provide high-quality tycorun battery for you to choose). In order to promote sales, valve regulated batteries were once known as “maintenance free batteries”. This name is a business name, not a technical name. At first, the excessive publicity and trust of “maintenance free” led to a series of equipment accidents. In the actual operation, the misunderstanding in this regard has been corrected and some necessary maintenance has been carried out.
Due to unreasonable use and maintenance free, the actual service life of the battery is only 30% ~ 50% of the design life. Reasonable maintenance can greatly prolong the service life of the battery. The current battery maintenance standards, specifications, systems and requirements of some departments are often formulated by some professional technical experts, which is not a summary of the actual maintenance experience. The makers have not practiced it, so they are gradually forgotten due to no practical effect in the grass-roots implementation. At present, the misunderstanding in understanding lags behind the development of maintenance technology. In the relevant professional colleges and universities that use more batteries, setting up battery courses is the fundamental measure to carry out battery training technical force.
- Standard of acid and water for storage battery
The sulfuric acid used in storage battery has high requirements for purity. Its standard grade is second only to chemical purity, and the price is 10 times that of industrial sulfuric acid. It is extracted from industrial sulfuric acid by stratified distillation, and its standard number is gb4554-84.
- Battery water quality control and simple inspection method
Due to the high requirements of sulfuric acid for storage battery, the content of many impurities is controlled at the micro standard, and the weighing method can not be used for its test. Therefore, most users are not qualified to control the quality of sulfuric acid used for storage battery. They use whatever the material supply department buys.
In a battery quality accident, the author went to several factories producing acid for battery for quality investigation. There are 16 consecutive test sheets in a factory, none of which is qualified, and some factories do not conduct a test for several months. Since the purchasing personnel of the material department do not identify the quality of the acid and do not know the standard of sulfuric acid used in the battery, sulfuric acid that does not meet the national standard will enter the production process.
Here are some simple test methods.
① As long as the bought bottled concentrated sulfuric acid has color, visible impurities, turbidity and unclear, and the density is less than 1.83g/cm ³， This concentrated sulfuric acid is definitely unqualified. The qualified products are clean, colorless and transparent without any mechanical impurities.
② The condensing pipe of the water device for burning storage battery is iron, and the fired purified water is often unqualified, so red copper pipe shall be used. Use conductivity meter to measure the resistance value of battery water. If it is greater than 100kq / m, it is qualified. Expressed by conductivity, it should be less than 1 μ S / cm, the two values are reciprocal, which is the easiest way. The resistance value of distilled water fired with glassware is usually 560k Ω / m. The water resistance value of ion exchange treatment is usually 900K Ω / m. At the time of purchase, the producer shall measure the conductivity of the water sample with a conductivity meter, and it is qualified if it meets the standard. Put your finger into the qualified water sample. Since the impurities on your hand are dissolved in water, the conductivity meter should show unqualified. In this way, we can roughly judge whether the conductivity meter is effective.
The quantitative analysis method for the content of chlorine (CL) and iron (FE) in battery water is as follows.
4.1. Quantitative analysis method of chlorine
The determination principle is that chloride ions react with silver ions to form milky silver chloride precipitation.
Reagent preparation is as follows.
① AgNO3 solution preparation. The concentration is 0.1mol/l, take 0.2g AgNO3 and dissolve it in 1000ml heavy distilled water.
② Preparation of chlorine standard solution. Take analytical pure sodium chloride, dry it at 450 ℃, transfer it to the dryer for cooling, weigh 0.1648g, put it into a 100ml beaker, add distilled water to dissolve it, transfer it into a 1000ml volumetric flask, add distilled water to dilute it to the scale, and then get the content of 0.1ml/l.
③ 1:1 nitric acid solution preparation. Take 10ml of analytical pure nitric acid, add 10ml of distilled water and mix well.
Operation steps: take 5ml of the solution to be tested, add 1 ~ 2 drops of nitric acid solution, and then drop the prepared AgNO3 reagent. If there is no milky white, it means there is no chlorine. If there is milky white, its chlorine content shall be compared with the milky white of the standard sample. Take chlorine free distilled water with another colorimetric tube. The operation is the same as above. Add chlorine standard solution with pipette or burette until the milky white is consistent with the solution to be measured. Note the ml of chlorine standard solution added.
Oxygen content is
4.2. Quantitative analysis method of iron
The principle of determination is that ammonia thiocyanate reacts with 3-valent iron ions to form hexathiocyanate iron complex anion. Iron hexathiocyanate complex anion is red, and the content of iron can be measured according to the depth of red. The anion formed by the reaction of divalent iron ions with ammonia thiocyanate does not show color, so divalent iron ions should be oxidized into trivalent iron ions with acid before determination. Reagent preparation is as follows.
① Preparation of standard solution. Take 0.8635g of pure iron ammonium vanadium Fe2 (SO4) for analysis,
(NH4) 2SO4 · 24h20, add distilled water to dissolve in 100ml Dissolve it in a beaker, transfer it into a 1000ml volumetric flask and dilute it to the scale with distilled water. The iron content of this standard solution is 0.1mg/ml
② The acid preparation of 1:1 nitric acid solution is the same as above.
③ Ammonia thiocyanate, solid, analytical purity.
The operation steps are as follows.
Take 5ml Put the solution to be measured into the colorimetric tube, add 1ml of 1:1 HNO3 solution, shake the test tube for 1min, add 1 ~ 2G solid thiocollar ammonia, and shake well. If the liquid to be tested does not show red, it indicates that the liquid to be tested does not contain iron; If it is red, it is necessary to compare the discoloration with standard iron solution.
Chlorine and iron are the harmful impurities most easily mixed into the electrolyte. As long as the two indicators are qualified in the water purification process, the control indicators of other impurities are often qualified.
Read more: State of charge of lead-acid batteries