Dongguan Everwin Tech Co., Limited Company News

Can lead-acid battery electric vehicles be changed to lithium-ion batteries? The reasons for not proposing to replace lead-acid battery electric vehicles with lithium-ion batteries are as follows: 1.the production cost of lithium-ion batteries is high. The production equipment is expensive and the labor cost accounts for about 40% of the production cost. The price is about three times that of lead-acid batteries. The cost-effectiveness of the three times price is not high, which gives people a sense of being flashy. In addition, lithium-ion batteries are difficult to recycle and the reuse rate is not high. 2.Due to the small size of lithium-ion batteries, multiple lithium-ion batteries are connected in series during assembly. During transportation and use, a solder joint may become disconnected or poorly soldered, which is a common problem when connecting lithium-ion batteries. 3.Lithium-ion batteries have potential safety hazards of fire and explosion. This is especially true when consumers unknowingly purchase inferior lithium-ion batteries online. In electric vehicles, the sealing conditions are not very good, and moisture easily leads to poor contact and other safety hazards. How to convert lead-acid battery electric vehicles into lithium-ion batteries The first step, taking a 48V lead-acid battery as an example, is to open the four corner screws of the battery and carefully open the top cover. You can see that there are 4 12V lead-acid batteries inside; The second step is to remove the wires from the battery with a soldering iron after remembering the battery circuit. Be careful to prevent the lithium-ion battery from short-circuiting during the operation. The third step is to take out all the old batteries and put the lithium battery in. When installing the battery, there are some small protruding plastics inside that separate the original lead-acid battery. This must be removed, otherwise the new battery will be worn out in the future. The fourth step is to connect the terminals on the lithium-ion battery and wrap them with electrical tape. However, it should be noted that when the original lead-acid battery is replaced with a lithium-ion battery, it must be required to match the voltage of the original vehicle battery, so that the capacity can be increased and the battery life will be longer. Even with the same capacity, the lithium-ion battery will have a longer battery life and life. Secondly, it should be noted that the original charger cannot charge lithium batteries, and a special charger must be purchased separately or customized.

How dry batteries workThe dry battery belongs to the primary battery in the chemical power supply, which is a disposable battery, which uses the carbon rod as the positive electrode and the zinc cylinder as the negative electrode to convert chemical energy into electrical energy to supply the external circuit. In chemical reactions, because zinc is more active than manganese, zinc loses electrons and is oxidized, and manganese gets electrons and is reduced. Dry batteries are not only suitable for flashlights, semiconductor radios, tape recorders, cameras, electronic clocks, toys, etc., but also suitable for special fields, scientific research, telecommunications, navigation, special use, medicine and other fields in the national economy, which are very easy to use. Generally, most dry batteries are manganese-zinc batteries, with a cathode carbon rod in the middle, a mixture of graphite and manganese dioxide, and a layer of fiber mesh outside. The net is coated with a thick electrolyte paste, which consists of ammonia chloride solution and starch, and a small amount of preservatives.The important working principle of dry batteries is that the redox reaction is realized in a closed loop. The electrode reaction formula of alkaline zinc-manganese dry battery is: Zn+2MnO2+2NH4Cl=ZnCl2++Mn2O3+2NH3+H2O What is the dry battery model?The models of dry batteries are generally divided into: 1, 2, 3, 5, and 7, of which No. 5 and No. 7 are particularly commonly used. The so-called AA battery is the No. 5 battery, and the AAA battery is the No. 7 battery! AA and AAA both indicate the battery model; With the development of science and technology, dry batteries have developed into a large family, with about 100 species so far. Common ones include general zinc-manganese dry batteries, alkaline zinc-manganese dry batteries, magnesium-manganese dry batteries, zinc-air batteries, zinc-mercury oxide batteries, zinc-silver oxide batteries, lithium-manganese batteries, etc.AA is what we usually call No. 5 battery, the general size is: diameter 14mm, height 49mm;AAA is what we usually call No. 7 batteries, and the general size is: diameter 11mm, height 44mm. What is the voltage of a dry battery?The voltage value of the dry battery is expressed in volts (V), also known as potential difference or potential difference, which is the energy difference caused by the difference in the electric potential of the positive and negative electrodes of the power lithium battery in the electrostatic field, and the voltage of the dry battery is a variable process in the environment of the dry battery.Dry battery voltage is divided into three types: standard voltage, open circuit voltage, and working voltage. General batteries are 1.5V, cadmium-nickel or nickel-metal hydride rechargeable batteries are 1.2V, there are also cylindrical lithium-ion batteries 3.7V, storage batteries 2V, etc., and Europe also has a zinc rechargeable battery 1.9V.

Can pouch polymer lithium-ion batteries burn and explode? Pouch polymer lithium-ion battery is a new type of battery with a variety of distinct advantages, such as high energy density, miniaturization, ultra-thinness, light weight, and high safety. In terms of shape, lithium polymer batteries have the characteristics of ultra-thinness, which can be made into batteries of any shape and capacity according to the requirements of various products. The minimum thickness that can be achieved by this type of battery can be as small as 0.5mm, and there is no memory effect. Pouch polymer lithium-ion battery is a lithium-ion battery product made of flexible packaging and polymer electrolyte, which will not explode when used and stored under normal circumstances, unless it is short-circuited due to strong destruction. The current polymer lithium-ion battery is mostly a pouch battery, using aluminum-plastic film as the shell, when the organic electrolyte is used inside, even if the liquid is very hot, it does not explode, because the aluminum-plastic film polymer battery uses solid or gelatinous state without leakage, but naturally broken.But nothing is absolute, if the instantaneous current is large enough to cause a short circuit, it is not impossible for the battery to spontaneously combust or burst, and the occurrence of mobile phone and tablet safety accidents is mostly caused by this situation. The correct way to charge polymer lithium-ion batteries 1. Please confirm the temperature when chargingIn a low-temperature environment, the low-temperature protection mechanism of the polymer lithium-ion battery will promote the chemical reaction of substances in the battery, so it cannot be charged or the charging speed is slowed down, and at high temperatures, the battery will be unstable and even cause an explosion! 2. Pay attention to the number of charging and frequent chargingThere is a saying: each mobile phone battery has a fixed number of charges, if the number of charging times is too much, it will accelerate the degree of battery aging and strain! In fact, this is wrong, frequent charging is actually slightly good for the battery!

After the pre-solution of the waste lithium-ion battery, the composition of the rupture products generally obtained is relatively complex, including the lithium-ion battery shell, cathode material, anode material, copper current collector, aluminum current collector, separator, electrolyte, etc., which should be further separated and solved. The recycling process of valuable metals is important for the metal recycling process of waste lithium-ion batteries, including physical separation, pyrometallurgy and hydrometallurgy. Regarding the usefulness of used lithium-ion batteries, we understand that cobalt, lithium, copper and plastics in spent lithium-ion batteries are precious resources with high recycling value. 1.Physical sorting methodThe physical separation method is a sorting method based on the particle size, density, magnetic and other material performance differences of the material, and the important ones include screening, gravity separation, flotation, magnetic separation, etc. Firstly, a vertical shredder, a wind shaker and a vibrating screen are used to classify and solve the waste lithium-ion battery, and after rupture and sorting, the cathode material, anode material, separator, current collector and so on are obtained. Then the cathode material and anode material are solved by 500°C heat, and then the lithium cobalt oxide and graphite are separated by flotation, and the recovery rate of lithium cobalt oxide in this process can reach 97%. 2.PyrometallurgyPyrometallurgical method should pre-solve the waste lithium-ion battery, strip off the battery shell, and then reduce the mixed material to roast, binders and other organic matter escape in the form of gas, most of the lithium oxide with low boiling point escapes in the form of steam, absorbed and recovered with water, and other metals (copper, nickel, cobalt, etc.) are formed into metal alloys, and then deep production is carried out with hydrometallurgical technology, and the fluorine and phosphorus in the electrolyte are solidified in the slag. Umicore International S.A. has a recycling plant with an annual capacity of 7,000 tons of used batteries in Oren, Belgium. Lithium-ion battery recycling is about to be the next industry to explode! The lithium-ion battery recycling market size may exceed 10 billion, and lithium-ion batteries contain less toxic substances, so it is not very meaningful to discuss his pollution problem. It is important to look at the control of the processing company.

From the perspective of lithium-ion battery structure, it is mainly divided into the following five parts: 1. Cathode materials: transition metal oxides or polyanionic compounds with layered or spinel structure with lithium intercalation ability with high electrode potential and stable structure, such as lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, ternary materials, etc. 2. Anode materials: layered graphite, metal elements and metal oxides with potential close to lithium potential, stable structure and many lithium storage, such as graphite, central phase carbon microspheres, lithium titanate, etc. 3. Electrolyte: an organic solvent dissolved in electrolyte lithium salt, supplying lithium ions, electrolyte lithium salts are LiPF6, LiClO4, LibF4, etc., and the organic solvent is mainly composed of one or several mixtures of diethyl carbonate, propylene carbonate, ethylene carbonate, dimethyl ester, etc. 4. Separator: placed between the positive and negative electrodes, guard against the positive and negative electrodes to touch straight, and promise the polyene microporous membrane through which Li + ions pass, such as polyethylene (PE), polypropylene (PP), or their composite films, PP/PE/PP three-layer separator. 5. Shell: battery packaging, mainly aluminum shell, cover plate, tabs, insulating sheets, etc.

At present, most of the domestic polymer lithium-ion batteries are only pouch batteries, using aluminum-plastic film as the shell, but the electrolyte has not changed. This kind of battery can also be thinned, its low-temperature discharge characteristics are better than polymer batteries, and the energy density of the material is basically the same as that of liquid lithium-ion batteries and general polymer batteries, but because of the use of aluminum-plastic film, it is lighter than ordinary liquid lithium batteries. In terms of safety, when the liquid is just boiling, the aluminum-plastic film of the pouch battery will naturally bulge or break, and it will not explode. 1. When charging the polymer lithium-ion battery, it is best to choose the original special charger, otherwise it will affect or damage the polymer lithium-ion battery.2. When charging polymer lithium-ion batteries, it is best to charge them slowly, and try to guard against fast charging, as repeated charging and discharging will also affect the life of polymer lithium-ion batteries.3. If the mobile phone is not used for more than 7 days, the polymer lithium-ion battery should be fully used before use, and the polymer lithium-ion battery has self-discharge 4. The charging time of polymer lithium-ion battery is not as long as possible, for general chargers, when the polymer lithium-ion battery is overflowing, it should stop charging immediately, otherwise the polymer lithium-ion battery will affect the battery performance due to heating or overheating.5. After the polymer lithium-ion battery is charged, try to leave it on the charger for more than 10 hours, and if it is not used for a long time, the mobile phone and the polymer lithium-ion battery should be separated.

Lithium iron phosphate powered lithium-ion battery has a cycle life of more than 2,000 times, and can reach 2,000 times when used with standard charging (5 hour rate). The lead-acid battery of the same quality is a new half a year, an old half a year, and a maintenance and maintenance half a year, at most 11.5 years, while the lithium-ion iron phosphate battery will be used for 7-8 years under the same conditions. All things considered, the performance-to-price ratio will be more than 4 times that of lead-acid batteries. Safe to useLithium iron phosphate completely deals with the safety hazards of lithium cobalt oxide and lithium manganese oxide, lithium cobalt oxide and lithium manganese oxide will explode under a strong collision and pose a threat to the life safety of consumers, while lithium iron phosphate will not explode even in the worst traffic accidents after strict safety detection. High temperature resistanceThe peak thermal peak of lithium iron phosphate can reach 350 °C and 500 °C, while lithium manganese oxide and lithium cobalt oxide are only about 200 °C. The operating temperature range is wide (-20C--+75C), and it has high temperature resistance, and the lithium iron phosphate battery heating peak can reach 350 °C and 500 °C, while lithium manganese oxide and lithium cobalt oxide are only about 200 °C. capacityIt has a larger capacity than general batteries (lead-acid, etc.). When a rechargeable battery is often overflowing, the capacity will quickly fall below the rated capacity value, a phenomenon called memory effect. Like nickel-metal hydride and nickel-cadmium batteries, there is no such phenomenon in lithium-ion iron phosphate batteries, no matter what state the battery is in, it can be charged and used at any time, and there is no need to put it away and then charge. No memory effectThe performance of lithium-powered lithium-ion batteries depends on the cathode and anode materials, and its safety performance and cycle life are incomparable with other materials, which are also the most important technical indicators of lithium-ion batteries. The cycle life of 1C charge and discharge is up to 2000 times. A single battery does not burn when overcharged at 30V, and does not explode when punctured. Lithium iron phosphate cathode materials make large-capacity lithium-ion batteries easier to use in series. To meet the requirements of frequent charging and discharging of electric vehicles.

What is a charge cycle Many people think that the life of a polymer battery is the number of charges, but in fact, it is not true, strictly speaking, it should be called the charging cycle. A full charge cycle is to charge 100% and then put 100% on charge. The life of a lithium battery is about 300-500 complete charging cycles. The correct statement about the life of lithium battery should be 300-500 times of full charge and discharge. That is to say, suppose a battery that is full of 100%: 50% is used, 30% is charged, this is not a complete cycle, a full cycle is charged and discharged two 100%, this is actually 40% cycle, and when you use 60% and charge 40%, then there will be 90% cycle. And so on; What to do if you don't use lithium batteryThe self-discharge rate of lithium polymer batteries is still a bit high, for the sake of insurance, if you don't use it, it is best to overflow first, and then seal it in a plastic bag and store it. It should be taken out and used once in 1-2 months, that is, charged and discharged once to maintain the activity of lithium ions. The maximum should not exceed 3 months, and it must be taken out and charged once. If you don't use it for too long, the lithium-ion activity will decrease, which will have an impact on battery life. How to charge it better?The last small suggestion, it is best not to use a miscellaneous charger to charge the original lithium battery, just use the equipment + original charger, or buy the original seat charger. Because miscellaneous chargers often do not use standard voltage and current, it is harmful to the original battery. Especially the old-fashioned charger with a discharge function, don't use it, if you accidentally over-discharge, the battery will be finished.

1.Thinner, better performanceIn the past, the battery was removable, so there was always some space in the middle, but after it became non-removable, the phone battery and the back cover of the phone will fit tightly. 2.SaferIf you are using non-original accessories, the chances of safety hazards are greatly increased. Today we use more power banks, as long as the capacity is large enough, it can generally charge the mobile phone several times, and it can also charge several mobile phones at the same time. 3.Easy to recycle and eco-friendlyToday, more and more advocate the theme of environmental protection, if it is a removable battery, the battery is broken, we may throw away the battery in other garbage, but in fact, the battery will cause great pollution to the environment, there are many heavy metal components. If it's non-removable, it's recycled with your phone, which is more environmentally friendly and easier to recycle.

The size of the parallel short-circuit current of lithium iron phosphate batteries depends on the rated current and number of batteries.It is calculated as follows: Parallel short-circuit current = Maximum battery current × Number of cells. 1. Calculation of parallel short-circuit current of lithium iron phosphate batteryWhen lithium iron phosphate batteries are connected in parallel, the calculation of short-circuit current is the key. It is directly related to the security and stability of the system. The size of the parallel short-circuit current is determined by the rated current of the battery, that is, the maximum current that the battery can output when it is working normally, and the number of batteries in parallel. With a simple mathematical formula, we can quickly derive the value of the parallel short-circuit current. 2. System security considerationsWhen designing a lithium iron phosphate battery parallel system, we not only need to calculate the short-circuit current, but also consider whether the rated current of the system is large enough to accommodate this current. If the parallel short-circuit current exceeds the system's rated current, it can lead to serious consequences such as battery overheating, combustion, or even explosion.Therefore, selecting the right battery, using a reliable connection, installing a temperature control device, and properly controlling the charging and discharging process are all important steps to ensure the safety of the system. 3. Factors affecting short-circuit currentIn addition to the rated current and number of batteries, there are some other factors that can also affect the short-circuit current of lithium iron phosphate batteries. For example, the internal design structure of the battery, the choice of electrode material, and the service life of the battery all have an impact on its safety. In addition, external environmental factors such as temperature, vibration, and external collisions can also cause short circuits inside the battery.To sum up, when designing and using a parallel system of lithium iron phosphate batteries, we must comprehensively consider various factors to ensure the safety and stability of the system. Through scientific calculation methods and rigorous safety measures, we can give full play to the advantages of lithium iron phosphate batteries to provide reliable power support for various applications.

At present, lithium-ion batteries are widely used in all walks of life in the field of industrial equipment, but because there are no conventional fixed specifications and size requirements in the industrial field, there are no conventional products for industrial lithium batteries, and they all need to be customized, so how long does it take to customize a group of lithium-ion batteries? Under normal conditions, the customization time of lithium-ion batteries is about 15 days;On the first day of receiving the order demand, the R&D personnel evaluate the order demand, quote the sample and set up the customized product project.Day 2: Selection and circuit design for the battery cells of the productDay 3: Determine the structure diagram with the customer and conduct business negotiations On the fourth day, we will start to purchase materials, test and debug verification of BMS protection board design, battery assembly, cycle charge and discharge, circuit, etcThen packaging, warehousing, quality inspection, delivery until transportation to the customer, the customer for sample testing, etc., under normal circumstances, it takes about 15 working days.Lithium battery assembly is not like the kind of unknown battery cells and BMS protection boards in small workshops, take them directly for series and parallel packaging, and ship them directly without testing and verification, this kind of battery is generally a price war, the battery price is very low and there is no after-sales guarantee, basically do a one-time business, buy batteries or it is recommended to go to a professional and regular battery manufacturer to buy, and the quality of after-sales is more guaranteed.

Today we're going to explore a very practical topic: why do batteries behave so differently at high and low temperatures? From smartphones to electric cars, batteries have become almost an integral part of our lives. But have you noticed that on a hot summer day, the phone's battery seems to drain very quickly, and on a cold winter day, the battery seems to suddenly lose its vitality? What exactly is the science behind this? Don't worry, I'll take you to find out. 1. Physical and chemical properties of battery materialsFirst of all, we have to talk about the core of the battery - the material. The performance of a battery is highly dependent on the materials used. Different materials have different sensitivities to temperature, which leads to differences in the performance of batteries at high and low temperatures. At high temperatures, some materials may become more active and conductive; But at low temperatures, they can become sluggish or even fail. It's like, if you let a tropical plant suddenly grow in the cold Arctic, it's going to have a hard time adapting. 2. The relationship between conductivity and temperatureNext, let's talk about conductivity. Conductivity is a measure of a material's ability to conduct electricity, and it is particularly sensitive to temperature. At high temperatures, the electrical conductivity of battery materials typically increases, which means that electrons can flow more easily, speeding up chemical reactions. At low temperatures, however, the situation is completely reversed. The internal resistance of the battery will increase, resulting in a decrease in the discharge performance of the battery. That's why your phone's battery drops so fast in the cold winter months.3. Differences in the behavior of electrolytesNow, let's talk about electrolytes. The electrolyte is the medium for ion flow in the battery, and its performance directly affects the charging and discharging efficiency of the battery. At high temperatures, the electrolyte can maintain good fluidity, but at low temperatures, it may become viscous or even solidify. This is like the freezing of river water in winter, which seriously affects the ion conduction inside the battery, resulting in a decrease in battery performance.4. Effects of thermal expansion and contractionIn addition, we cannot ignore the effects of thermal expansion and contraction. Batteries are made up of a variety of materials that expand or contract at different rates when the temperature changes. If not properly controlled, this expansion and contraction may lead to damage to the battery structure, which in turn can affect the performance and life of the battery. It's like a house, if the foundation is not strong, the slightest bit of wind and grass can cause problems. 5. Limitations of chemical reaction kineticsThe process of charging and discharging a battery is actually a process of a series of chemical reactions. These chemical reactions accelerate at high temperatures but slow down at low temperatures. Imagine how difficult it is to get a group of people to run a marathon quickly in the cold wind in the winter. Similarly, low temperatures can slow down the chemical reactions inside the battery, resulting in a decrease in the battery's charge-discharge performance.6. Consideration of battery safetySafety is an important factor that cannot be ignored in battery design. At high temperatures, the battery may be at risk of overheating or even thermal runaway, while at low temperatures, the battery's performance degradation may affect the use of the device. Therefore, battery manufacturers must design batteries with these temperature factors in mind to ensure that the batteries are both safe and reliable. It's like designing a car with both its performance on the highway and its safety on rugged mountain roads. 7. Current solutions and challengesScientists and engineers have developed solutions to these challenges. For example, the performance of the battery at low temperatures can be improved by using special materials and designs. However, these solutions often face both cost and technical challenges. How to improve battery performance while controlling costs and ensuring safety is a problem that battery manufacturers need to solve. Through the discussion, we learned about the complexity of the difference in battery performance at high and low temperatures. Although current battery technology cannot completely solve this problem, with continuous research and innovation, we have reason to expect that future batteries will be able to better cope with the challenges of high and low temperatures. It's like a marathon with no end in sight, and scientists and engineers are moving forward to reach new destinations.