"Lithium battery" is a type of battery that uses lithium metal or lithium alloy as the anode material and uses a non-aqueous electrolyte solution. In 1912, the lithium metal battery was first proposed and studied by Gilbert N. Lewis. In the 70s of the 20th century, M.S. Whittingham proposed and began to research 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 applied for a long time. With the development of science and technology, lithium batteries have now become the mainstream.

Lithium batteries can be broadly divided into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain lithium in a metallic state and are rechargeable. The fifth-generation product of rechargeable batteries, lithium metal batteries, was born in 1996, and its safety, specific capacity, self-discharge rate and performance-to-price ratio are all better than those of lithium-ion batteries. Due to its own high technical requirements, only a few companies in a few countries are now producing such lithium metal batteries.

Lithium-ion batteries can only be charged and discharged 500 times?
I believe that the vast majority of consumers have heard that the life of lithium batteries is "500 times", 500 times of charge and discharge, more than this number of times, the battery will "end of life", many friends in order to be able to extend the life of the battery, every time the battery is completely exhausted before charging, so that the life of the battery really has a prolonging effect? The answer is no. The life of a lithium battery is "500 times", which refers not to the number of charges, but to a cycle of charge and discharge.
A charging cycle means that all the battery power is used from full to empty, and then from empty to full, which is not the same as a single charge. For example, a lithium battery uses only half of its power on the first day, and then fully charges it. If it is still the case the next day, that is, it will be charged half of it, and a total of two charges will be charged, which can only be counted as one charging cycle, not two. As a result, it can often take several recharges to complete a cycle. With each completed charge cycle, the battery capacity decreases a little. However, this reduction in power is very small, and high-quality batteries will still retain 80% of their original capacity after multiple cycles, and many lithium-powered products are still in use after two or three years. Of course, lithium batteries still need to be replaced after the end of their life.
The so-called 500 times means that the manufacturer has achieved about 625 rechargeable times at a constant discharge depth (such as 80%), reaching 500 charging cycles.
(80%*625=500)
And due to the various effects of real life, especially the depth of discharge when charging is not constant, so "500 charge cycles" can only be used as a reference battery life.

Correct statement: The life of lithium battery is related to the number of completion of the charging cycle, and there is no direct relationship with the number of charging times.
Simple understanding, for example, a piece of lithium battery uses only half of the charge on the first day and then fully charges it again. If it is still the case the next day, that is, it will be charged half of it, and a total of two charges will be charged, which can only be counted as one charging cycle, not two. As a result, it can often take several recharges to complete a cycle. With each completed charge cycle, the charge decreases a little. However, the reduction is very small, and high-quality batteries will still retain 80% of the original power after multiple cycles, and many lithium-powered products are still in use as usual after two or three years, which is the reason. Of course, the lithium battery still needs to be replaced in the end when it reaches its life.

The life of lithium battery is generally 300~500 charging cycles. Assuming that the amount of electricity provided by a complete discharge is Q, if the reduction of power after each charge cycle is not considered, the lithium battery can provide or supplement a total of 300Q-500Q of power during its lifetime. From this, we know that if you charge 1/2 each time, you can charge 600-1000 times; If you charge 1/3 each time, you can charge 900~1500 times. And so on, if it is charged randomly, the number of times is indefinite. In short, no matter how it is charged, a total of 300Q~500Q of electricity is replenished, which is constant. Therefore, we can also understand it this way: the life of lithium battery is related to the total charging power of the battery, and has nothing to do with the number of charges. There is little difference between deep and shallow charging and shallow charging on the life of lithium batteries.

In fact, shallow discharge and shallow charging are more beneficial for lithium batteries, and only when the power module of the product is calibrated for lithium batteries, there is a need for deep discharge and deep charging. Therefore, the use of lithium battery powered products do not have to stick to the process, everything is convenient, charge at any time, do not have to worry about affecting the life.
If the lithium battery is used in an environment higher than the specified operating temperature, i.e. above 35°C, the battery will continue to decrease, that is, the battery will not be powered for as long as usual. If you have to charge the device at such temperatures, the damage to the battery will be even greater. Even storing batteries in a hot environment will inevitably cause corresponding damage to the quality of the battery. Therefore, keeping it at a suitable operating temperature as much as possible is a good way to extend the life of the lithium battery.

If you use lithium batteries in a low temperature environment, that is, below 4 °C, you will also find that the battery life is 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, unlike use in a high-temperature environment, once the temperature rises, the molecules in the battery are heated and immediately return to their previous power.
In order to maximize the efficiency of lithium-ion batteries, it is necessary to use them frequently, so that the electrons in the lithium battery are always in a flowing state. If you don't use lithium battery often, please remember to complete a charging cycle for lithium battery every month and do a power calibration, that is, deep discharge and deep charge once.
The formal name is "charge and discharge cycle", not equal to "charge times", the cycle refers to the battery from full charge to use up, this is a cycle, if your battery from a full state, used a tenth of the power, and then full again, this is a tenth of a cycle, so that 10 times, is basically a cycle. Again, from a full charge, half of it is used and then it is fully charged, and then it is half of it and then it is fully charged, which is also a cycle, at which point you are charged twice. Therefore, the cycle only depends on the "cumulative amount of power released from the battery", and is not directly related to the "number of charges".

How to maintain the battery of your mobile phone:
1. Each time it is fully charged, it can reduce the number of charging times and improve the battery life.
2. You don't need to completely discharge the battery, usually the power is less than 10% and you need to charge it.
3. Use the original charger to charge, do not use the universal charger to charge.
4. Do not use your phone during charging.
5. Don't overcharge, stop charging after the battery is full.

According to the experimental results, the life of lithium batteries is constantly attenuated with the increase of charging times, and the general charging times of lithium batteries are 2000-3000 times. Cycle is use, we are using the battery, we are concerned about the time of use, in order to measure the performance of how long the rechargeable battery can be used, the definition of the number of cycles is specified. Actual user use is ever-changing, because the test with different conditions is not comparable, and the definition of cycle life must be standardized in order to be compared.

Lithium battery cycle life test conditions and requirements stipulated in the national standard: under the condition of ambient temperature of 20 °C ± 5 °C, charge at 1C, when the battery terminal voltage reaches the charging limit voltage of 4.2V, change to constant voltage charging, until the charging current is less than or equal to 1/20C, stop charging, put on hold for 0.5h~1h, and then discharge at 1C current to the termination voltage of 2.75V, after the discharge is over, set aside for 0.5h~1h, and then carry out the next charge-discharge cycle until the discharge time is less than 36min for two consecutive times , it is considered to be at the end of life, and the number of cycles must be greater than 300 times.