"Lithium battery" is a type of battery that uses lithium metal or lithium alloy as the negative electrode material and uses a non-aqueous electrolyte solution. In 1912, the lithium metal battery was first proposed and studied by GilbertN.Lewis. In the 1970s, M.S.Whittingham proposed and began to study lithium-ion batteries. Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal have very high environmental requirements. Therefore, lithium batteries have not been used for a long time. With the development of science and technology, lithium batteries have now become the mainstream.
Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium ion batteries. Lithium-ion batteries do not contain lithium in the metallic state and are rechargeable. The fifth generation of rechargeable batteries, lithium metal batteries, was born in 1996, and its safety, specific capacity, self-discharge rate and performance-price ratio are better than lithium-ion batteries. Due to its own high technical requirements, only companies in a few countries are now producing such lithium metal batteries.
Lithium-ion batteries can only be charged and discharged 3000 times?I believe that most consumers have heard that the life of lithium batteries is "3000 times", and 3000 times of charge and discharge, beyond this number of times, the battery will "end of life", many friends in order to prolong the life of the battery, every time in Does it really prolong the life of the battery by charging it when the battery is completely depleted? the answer is negative. The life of a lithium battery is "3000 times", which refers not to the number of times of charging, but a cycle of charging and discharging.
A charging cycle means that all the power of the battery is fully charged from full to empty, and then charged from empty to full, which is not equivalent to charging once. For example, a lithium battery is only half charged on the first day, and then fully charged. If the next day is still the same, that is, half of the charge, a total of two charges down, this only counts as one charge 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 reduction in power is very small. High-quality batteries will still retain 80% of their original capacity after being charged for many cycles. Many lithium-ion battery-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 3000 times means that the manufacturer has achieved about 3750 rechargeable times at a constant depth of discharge (such as 80%), reaching 500 charging cycles.
(80%*3750=3000) (ignoring factors such as lithium battery capacity reduction)
However, due to various influences in real life, especially the depth of discharge during charging is not constant, "3000 charging cycles" can only be used as a reference battery life.
Correct statement: Lithium battery life is related to the number of completed charging cycles, not directly related to the number of charging cycles.
Simple understanding, for example, a lithium battery is only half charged on the first day, and then it is fully charged. If the next day is still the same, that is, half of the charge, a total of two charges down, this only counts as one charge cycle, not two. Therefore, it may usually take several charges to complete a cycle. Each time a charge cycle is completed, the charge decreases a bit. However, the reduction is very small. High-quality batteries will still retain 80% of the original power after being charged for many cycles. Many lithium-ion battery-powered products are still used as usual after two or three years. This is the reason. Of course, the lithium battery life will eventually need to be replaced.
The life of lithium batteries is generally 2000 to 3000 charging cycles. Assuming that the power provided by a complete discharge is Q, if the reduction of power after each charging cycle is not considered, the lithium battery can provide or supplement a total of 2000Q-300Q of power during its life. From this, we know that if you charge 1/2 every time, you can charge 4000-6000 times; if you charge 1/3 every time, you can charge 6000-9000 times. And so on, if charging randomly, the number of times is not fixed. In short, no matter how you charge it, the total added power of 2000Q to 3000Q is constant. Therefore, we can also understand this: the life of lithium batteries is related to the total charging capacity of the battery, and has nothing to do with the number of charging times. Deep discharge and deep charge and shallow discharge and shallow charge have little difference in the impact of lithium battery life.
In fact, shallow discharge and shallow charge are more beneficial for lithium batteries. Only when the power module of the product is calibrated for lithium batteries, is it necessary to deep discharge and charge deeply. Therefore, products powered by lithium batteries do not have to stick to the process, everything is convenient, and they can be charged at any time without worrying about affecting their lifespan.
If the lithium battery is used in an environment higher than the specified operating temperature, that is, above 35°C, the power of the battery will continue to decrease, that is, the battery will not last as long as usual. If the device is charged at such a temperature, the damage to the battery will be even greater. Even if the battery is stored in a hot environment, it will inevitably cause corresponding damage to the quality of the battery. Therefore, trying to maintain a suitable operating temperature is a good way to extend the life of lithium batteries.
If the lithium battery is used in a low temperature environment, that is, below 4°C, the battery life will also be reduced, and 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, different from the use in a high temperature environment, once the temperature rises, the molecules in the battery are heated and immediately return to the previous power level.
To get the most out of a lithium-ion battery, you need to use it frequently so that the electrons in the lithium-ion battery are always in a state of flow. If you do not use the lithium battery often, please remember to complete a charging cycle for the lithium battery every month and do a power calibration, that is, deep discharge and deep charging.
The formal name is "charge-discharge cycle", which is not equal to "charge times". The cycle refers to the time when the battery is fully charged to run out. This is a cycle. If your battery is fully charged, one tenth is used. This is a tenth of a cycle, so 10 times of charging is basically a cycle. Similarly, from fully charged, half used and then fully charged, and then half used and then fully charged, this is also a cycle. At this time, you have charged twice. So, the cycle only depends on "how much power is discharged from the battery", and has no direct relationship with "number of charges".
Moreover, the nominal number of charge and discharge cycles does not mean that it cannot be used after it is used up, but after so many cycles, the ability of the battery to store electricity will drop to a certain extent.
For example, a lithium battery, the nominal charge-discharge cycle is "not less than 80% of the nominal capacity after 3000 times"
That is, after 3000 cycles, the battery can only store as much power as 80% of the new battery at most, and the performance has dropped to a certain extent.
Lithium batteries do not have a fixed number of charging times. Generally, batteries from regular manufacturers can be charged and discharged at least 2,000 times, and the capacity remains above 80% of the initial capacity. One charge a day can be used for 5 years.