In 1912, the lithium metal battery was first proposed and studied by Gilbert N. Lewis. In the 1970s, M.S. Whittingham proposed and began to study lithium-ion batteries. Due to lithium metal’s very active chemical properties, the processing, storage, and use of lithium metal have very high environmental requirements. Therefore, lithium batteries were not used for a long time. With the development of science and technology, lithium batteries have now become mainstream.
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Lithium batteries can roughly divide into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain metallic lithium and are rechargeable. The fifth generation of rechargeable batteries, lithium metal batteries, was born in 1996. Its safety, specific capacity, self-discharge rate, and performance-price ratio are superior to lithium-ion batteries. Due to its high-tech requirements, only a few companies in a few countries are producing such lithium metal batteries.
The lithium-ion battery can only be charged and discharged 500 times?
I believe that most consumers have heard that the life of a lithium battery is “500 times”, 500 times of charge and discharge, beyond this number of times, the battery will “end of life”, many friends to be able to extend the battery life, every time The battery charge only when it is entirely exhausted. Does this open the life of the battery. The answer is negative. The lifespan of a lithium battery is “500 times”, which does not refer to the number of charging times, but a cycle of charging and discharging.
A charging cycle means using all the power of the battery from full to empty and then from empty to full. This is not the same as charging once. For example, a lithium battery used only half of its power on the first day, and then it was fully charged. If the situation persists the next day, use half of the charge and set it twice in total. This can only be counted as one charging cycle, not two. Therefore, it may usually take several times to complete a process. Every time a charging cycle is completed, the battery capacity will decrease a bit. However, this reduction in power consumption is minimal. High-quality batteries will still retain 80% of the original total after being charged for many cycles. Many lithium-powered products are still used as usual after two or three years. Of course, the lithium battery still needs to be replaced after the end of its life.
The so-called 500 times means that the manufacturer has achieved about 625 charging cycles at a constant depth of discharge (such as 80%), reaching 500 charging cycles.
(80%*625=500) (Ignore factors such as reduction of lithium battery capacity)
However, due to various influences in real life, especially the depth of discharge during charging is not constant, “500 charging cycles” can only be used as a reference battery life.
The correct statement: Lithium battery life is related to the number of completions of the charging cycle, not directly related to the charging cycles.
Simple understanding, for example, a lithium battery used only half of its power on the first day and then fully charged it. If the situation persists the next day, use half of the charge and set it twice in total. This can only count as one charging cycle, not two. Therefore, it may usually take several times to complete a process. Every time a charging cycle complete, the power will decrease a bit. However, the reduction is minimal. High-quality batteries will still retain 80% of the original power after being charged for multiple cycles. Many lithium-powered products still use as usual after two or three years. This is the reason. Of course, the life of the lithium battery will eventually need to be replaced.
The life of a lithium battery is generally 300 to 500 charging cycles. Assuming that the power provided by a complete discharge is Q if the reduction in capacity after each charging process is not considered, the lithium battery can provide or supplement 300Q-500Q of power in its life. From this, we know that if you charge 1/2 each time, you can trust 600-1000 times; if you charge 1/3 each time, you can set 900-1500 times. By analogy, if it has been accused randomly, the number of times is variable. In short, no matter how it is charged, it is constant to add a total of 300Q to 500Q of power. Therefore, we can also understand it this way: the life of a lithium battery is related to the battery’s total charge capacity. It has nothing to do with the number of recharges. Deep discharge and serious charge and shallow discharge and shallow charge have little difference in the impact on the life of the lithium battery.
Shallow charging and shallow charging are more beneficial to lithium batteries. When the product’s power module is calibrated for lithium batteries, it is necessary to deep discharge and severe charge. Therefore, products powered by lithium batteries do not need to be constrained by the process. Everything is convenient and can be charged at any time without worrying about affecting the lifespan.
If the lithium battery is used in an environment higher than the specified operating temperature, that is, 35°C or higher, the battery’s power will continue to decrease. That is, the battery’s power supply time will not be as long as usual. If you have to charge the device at such a temperature, the battery’s damage will be even more significant. Even if the battery is stored in a hot environment, it will inevitably cause corresponding damage to the quality of the battery. Therefore, keeping the operating temperature as suitable as possible is an excellent way to extend the life of the lithium battery.
If you use the lithium battery in a low-temperature environment, that is, below four °C, you will also find that the battery life is reduced. The original lithium battery of some mobile phones cannot even be charged in a low-temperature environment. But don’t worry too much. This is only a temporary situation, which is different from the use in a high-temperature environment. Once the temperature rises, the molecules in the battery will be heated, and they will immediately restore the previous power.
Suppose you want to maximize the effectiveness of lithium-ion batteries. In that case, you need to use them frequently so that the electrons in the lithium battery are always flowing. If you don’t use the lithium battery often, please remember to complete a charging cycle for the lithium battery every month and do a battery calibration, deep discharge, and severe charge once.
The formal name is “charge-discharge cycle”, which is not equal to the “number of recharges”. A cycle refers to the battery from fully charged to deplete. This is a cycle. If your battery is fully charged, it takes one-tenth. It’s the tenth cycle, so it’s a cycle when it’s been accused ten times.
Similarly, from full power, half used and then complete, then half used and then whole again, this is also a cycle. At this time, you are charging twice. Therefore, the process only depends on “how much electricity is discharged from the battery”, and has no direct relationship with the “number of recharges”.
Moreover, this nominal number of charge and discharge cycles does not mean that it cannot be used after it is used up, but after so many processes, the battery’s ability to store power will drop to a certain level.
For example, for a lithium battery, the nominal charge-discharge cycle is “not less than 60% of the nominal capacity after 500 times”.
After 500 cycles, this battery can only store as much as 60% of the time when a new battery was stored. This means that the performance has dropped to a certain level.
There is no fixed limit on the number of recharges for lithium batteries. The batteries from regular manufacturers can generally be charged and discharged at least 500 times. The capacity remains above 80% of the initial total, and it can be used for two years once a day is charged. Usually, if the mobile phone battery is charged 1,000 times, the battery will be severely unusable.
Cell phone battery maintenance method:
1. It is fully charged each time to reduce the number of charging and increase the battery life.
2. There is no need to discharge the battery completely; usually, it needs to be charged when the battery is less than 10%.
3. Use the original charger to charge, do not use the universal charger.
4. Do not use the mobile phone during the charging process.
5. Don’t overcharge; stop charging after the battery is full.
According to the experimental results, the lifespan of lithium batteries decays as the number of recharges increases. Generally, the number of recharges of lithium batteries is 2000-3000 times.
The cycle is used. We are using batteries. What we care about is the time of service. To measure the performance of how long a rechargeable battery can be used, the definition of the number of cycles is stipulated. The actual user usage is ever-changing because tests with different conditions are not comparable, and the meaning of cycle life must be standardized if there is a comparison.