Do you know enough about lithium batteries? Is it right to say that lithium-ion batteries can only be charged and discharged 500 times? What are the taboos of lithium battery? What is the service life of lithium battery? GHstore, a famous online store service provider, has analyzed the general knowledge and service life of lithium batteries as follows.
Lithium battery charging cycle analysis
Is it right to say that lithium-ion batteries can only be charged and discharged 500 times? I believe most consumers have heard that the life of lithium batteries is "500 times", 500 times charge and discharge, more than this number of times, the battery will "end of life", many friends in order to extend the life of the battery, each time the battery power is completely exhausted In order to extend the life of the battery, many friends every time the battery is completely depleted before charging, so that the battery life really has an extended role? The answer is no. The life of lithium batteries is "500 times", referring not to the number of charges, but a charge and discharge cycle.
A charging cycle means that all the power of the battery from full to empty, and then from empty to full process, which is not the same as charging once. For example, a lithium battery on the first day only used half of the power, and then charged it again. If it is still so on the second day, charging it with half, and charging it down twice in total, this can only be counted as one charging cycle, not two. Therefore, it may usually take several charges to complete a cycle.
Each time a charge cycle is completed, the battery capacity decreases a little. However, this lesser magnitude of power is very small, high-quality batteries will still retain more than 80% of their original capacity after charging through multiple cycles, and many lithium-powered products are still used as usual after 5-10 years. Of course, the lithium battery life to the final after still need to be replaced. And the so-called 500 times, refers to the manufacturer in a constant depth of discharge to achieve a chargeable number of about 625 times, reaching 500 charging cycles. Due to the various effects of real life, especially when charging the depth of discharge is not constant, so the "500 charge cycles" can only be used as a reference battery life.
The three taboos of lithium batteries
The first is the temperature, lithium batteries are afraid of high temperature.
The second is the current, such as 18650 lithium battery cell is 3C discharge, your electric bike car is 8000W, with a lower cell than your electric bike discharge current, which will lead to high temperature lithium battery, the current is too large and shortened life, there will be bulging scrap, if your electric bike power is very large, very fast, it is recommended to choose the 10C current 18650 cell If your electric bicycle is very powerful and fast, it is recommended to choose a 10C current 18650 cell, so it is obviously very important to choose the right cell!
Third is the full charge storage, ternary lithium battery full charge is 4.35V, the current market protection plate is 4.2V on the cut-off charge, so many people buy electric car lithium batteries are said to have no nominal capacity, in fact, this is the reason, the general long-term storage of electric car lithium battery, filled with half a 50 percent of the electricity is the best, such as you buy a new cell phone, many are on 50 percent of the power. If the full charge is stored for a long time, it will reduce the capacity of lithium batteries. Lithium iron phosphate and lithium titanate, except for these two can be fully charged storage, you also need to pay attention to is to choose a better quality protection plate, lithium batteries are the biggest taboo is to overcharge over discharge, ternary lithium over discharge once scrapped, overcharge must be bulging also scrapped.
electric car lithium battery life: "salt bath" way to extend the life
Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) yesterday published a research report, the agency scientists invented a simpler way to extend the life of rechargeable lithium batteries, the agency named this way "salt bath".
It is reported that the method was discovered by CSIRO in cooperation with RMIT University and Queensland University of Technology. According to the CSIRO researchers, the material they use is an ionic liquid, which is also known as room temperature molten salt, is a transparent, colorless, odorless, and flame retardant unique liquid, these materials can form a protective film on the surface of the electrode, so that the battery in use to maintain stability. The process and principle of treating the battery is to submerge the lithium metal electrodes in a mixed electrolyte containing ionic liquid and lithium salt before battery assembly. After this treatment, not only can the life of the battery be extended, but also the range of the battery can be extended and the performance and safety can be enhanced to some extent.
Electric car lithium battery life analysis
At this stage, various manufacturers try to develop electric cars carrying batteries are basically batteries (mainly lithium-ion batteries) and fuel cells, fuel cells due to the high cost of research and development and maintenance costs (fuel cells are about three to four times the maintenance costs of batteries), not quite suitable for the development of electric cars at this stage. So let's put aside for the time being, just say that the lithium battery is now commonly used.
The service life of lithium-ion batteries in ordinary electronic products is about 5 to 20 years, with an average of 8 years, while with the current level of technology, the service life of lithium-ion batteries in electric cars is about 7-15 years. When the battery capacity on an electric car decays to less than 80% of its initial capacity, the range of the electric car will be significantly reduced, and when the battery capacity decays to less than 70%, the battery must be replaced. For many of the current pure electric cars, the cost of the battery accounts for about 40% of the total cost of the car, which means that replacing the battery is equivalent to changing the small half of the car.
Electric bicycle lithium battery life analysis
Due to the instability of lead-acid battery performance and safety, middle and high-end electric bicycles are increasingly using lithium batteries. According to normal usage habits (about 15-20 km per day), the life span of an ordinary lithium battery electric bicycle is about 2-3 years, while the life span of a high quality lithium battery electric bicycle can reach 3-5 years.
So it is important for consumers to choose high quality electric bikes when possible. At the same time, the cost of lithium batteries accounts for about 30% of the total cost of an electric bike, and the cost of an electric bike is much lower than that of an electric car, so the cost of battery replacement is within the reach of most people.