Is there any damage to lithium batteries for overcharging?

Charging time and overcharging are not a concept. Overcharge means that the voltage is higher than the charge cut-off voltage during charging, and the general lithium battery is 4.2V. The voltage determines whether the battery is overcharged and has nothing to do with how much time to charge. Generally, due to the charger or the battery management chip in the mobile phone, the highest output voltage to the positive and negative terminals of the battery is 4.2V. Even if it is over, there is a protective board built into the lithium battery. This means that the voltage to the cell will never exceed 4.2V. It will not be overcharged for a long time. The subject can be assured that it will not damage the phone battery. But be careful not to plug in the charger for too long, such as two days a day. If it is too long, the charger will also be charged. Second, the phone will cut off the power, so the battery will be used. This may start charging again, then fill it up, then use it again, although the shallower Charge and discharge have little effect on the life of lithium batteries, but it has always been a long-term life.

Lithium battery deep charge deep, the battery loss will be greater, the ideal state of lithium battery work is shallow charge, then the battery life will be longer. According to the introduction of the Leopard lithium battery engineer, Lithium battery charge and discharge is chemically a redox reaction. Physically, lithium ions do reciprocating motion, so they also become "swinging" batteries. When charging, lithium ions are released and embedded in the negative electrode. If the battery is overcharged, the positive electrode structure collapses. The negative electrode is deposited with excess lithium ions, and the negative electrode surface is deposited. When discharging, the lithium ions are taken out of the negative electrode and returned to the positive electrode. If excessive discharge occurs, the negative electrode carrier copper ions are precipitated and run to the negative electrode. The surface, even the surface of the positive electrode, affects the structure of the positive and negative active materials and fails. Lithium battery charging is generally set to two steps, divided into two processes, a constant current charging process and a constant voltage charging process, wherein the constant current charging process accounts for most of the charging time, and the constant voltage charging is a trickle charging process during the charging process. Pay attention to the occurrence of overcharging of lithium battery. The regular lithium battery charger will set the charging procedure according to the characteristics of the lithium battery. The lithium battery pack has a protection board to prevent the lithium battery from overcharging. First, set the lithium battery charging limit as required Lithium battery charging current and charging voltage are the two most important parameters in lithium battery charging, which is not only related to the lithium battery charging performance but also related to the safety of lithium battery use, high current or exceed lithium The upper limit of battery charging will affect the performance of the lithium battery, or there may be dangerous situations such as fire and explosion. Therefore, when charging the lithium battery, pay attention to the charging voltage and charging current, and choose the lithium battery charger. If the charging voltage of the single-cell lithium battery is 4.2V, the multi-cell lithium battery charging voltage = 4.2V* lithium battery series number two. The minimum discharge voltage is 2.75V. In addition, pay attention to the discharge cutoff voltage of the lithium battery, that is, the discharge termination voltage of the lithium battery. The ideal discharge cutoff voltage of the lithium battery is 3.0, but the setting of the discharge cutoff voltage of the lithium battery in actual use will be different, usually it is lower than 3.0V in order to make full use of the battery power, and the most common is to set the discharge termination voltage to 3.0V. The battery is charged when the battery is discharged to the termination voltage.

2017 battery industry development main theme "ternary lithium battery" has become the mainstream "quality reduction" is the main theme of the industry development in 2017, the market quickly gathered to leading enterprises, the industry differentiation phenomenon intensified. In the field of materials, the imbalance between supply and demand of upstream raw materials has led to further increases in prices, the process of high-nickelization of ternary materials has accelerated, and the performance of lithium iron phosphate, separators and electrolytes has steadily improved. In the field of equipment, corporate performance has generally improved, while the period of account has been extended. The risk of funding shortages is also expanding. Compared with 2016, there are two obvious changes in the lithium battery industry market in China in 2017: First, under the boom of investment expansion, mergers and acquisitions, competition among leading enterprises has intensified; second, ternary lithium in the field of power batteries The battery market will increase dramatically.

The application of ternary lithium batteries in the field of power batteries has become mainstream this year. Large-scale lithium iron phosphate battery companies such as Ningde Times, BYD, and Guoxuan Hi-Tech have begun to increase the production capacity of ternary lithium batteries. From the perspective of various types of batteries, in the first 10 months of 2017, the total installed capacity of 18.1GWh lithium battery, ternary/manganese battery accounted for 5.05GWh, accounting for 55.03%, compared with 54.49% in the first nine months. Among them, lithium manganate battery is less than 0.9GWh, and lithium iron phosphate battery is 7.48GWh, accounting for 43.51%, which is down compared with 44.27% in the first nine months.

From setting up a double point policy to increasing the proportion of loan issuance, and then officially opening special number plates in many cities, the new energy vehicle industry is enjoying positive results. Therefore, since the third quarter, China's electric vehicles have begun to gradually increase in volume, sales have increased significantly, and the demand for batteries has also increased. In the first three quarters of this year, the total installed capacity of vehicle power batteries in China was 14.75GWh, a year-on-year increase of 24.14%. Therefore, battery companies have achieved significant growth in revenue. At present, the most equipped batteries for new energy vehicles are ternary batteries and lithium iron phosphate batteries. Affected by the policy, domestic lithium carbonate prices, which are indicators of lithium trading, rose to 159,000 yuan per ton in mid-November, the highest in history.

1. Battery companies have a clear positioning in the new energy vehicle segment market. The number of orders received by leading companies has increased significantly. Waterma has signed orders totaling more than 10.3 billion yuan this year, relying on high-energy lithium iron phosphate batteries to focus on passenger cars and special-purpose vehicles. BAK battery received orders for Hebei Yujie 18650 battery and Dongfeng Liuqi 10 million 2000 sets of power battery packs, mainly targeting the passenger car market. There are also small and medium-sized battery companies, Hengyuan New Energy, which has received an order of 1.5 billion yuan from Zhejiang Geely, which has received industry attention. 2, the third-party power battery PACK field appeared "unicorn" Pride from January to November 2017 totaled 4.6 billion orders. Compared with other third-party PACK companies, Pride is unable to match many opponents. 3. The energy storage market is heating up this year. Zhongtian Energy Storage, Nandu Power Supply, and Shuangdeng Group have all received orders. For example, Zhongtian Storage Energy and Xingxin Smart Energy signed a commercial contract for a 10MWh lithium battery energy storage project.

Recently, there has been a rumor that the lithium battery that is about to be scrapped is put into the refrigerator for three days, and then it can be brought back to life and resumed use. Is there such a god?

The battery mentioned in the next paragraph refers to the lithium battery used in notebook computers. Maybe there is some reason for the lithium battery used in mobile phones (I am not sure), but it is not the nickel-hydrogen battery commonly used in ordinary cameras or other. What battery. In fact, there is evidence that the deep charge and discharge method is effective for nickel-metal hydride batteries, and freezing is equivalent to deep charging and discharging of the battery in disguise, so it should be effective (of course, few people will save money for a few dry batteries). There is a huge risk that the battery may explode). However, the aging of lithium batteries is generally caused by the disintegration of the battery material and is irreversible.

The time given by the shell net is too short. I can't find a scrapped battery to do the experiment myself. And because I have more than 50% of the suspicion that doing so will cause permanent damage to the battery, so I really can't bear to take the battery to try, I have to collect and sort out the information on the network.

First of all, I noticed that this incident is said to have been tested in the "Life Survey" section of Beijing TV Station. The result is: useless! But now that the experts are flooding, the TV station is looking for an expert to explain it casually and then say it is useless, is it really useless? So why are there so many people on the Internet?

I want to find more people who are useful. Skip those plagiarism reposts and no evidence of embarrassment, the earliest experimental text I can find on the domestic Internet is a 2005 post titled "Zombie Resurrection of the Notebook Lithium Battery Rebirth". (See http://www.pxue.com/Html/311.html, yes, I know this is not the original post. The post was clearly written from the special network (51nb.com), but I don’t know what it is. The reason, the original post on the special online has disappeared. @小园听风同学, your entry point and I really coincide!)

What deserves our attention is that the author of the article clearly pointed out that this is the way he recovered the mobile phone battery from a mobile phone forum in Hong Kong. He used it on a laptop battery. And after a preliminary search, I did not find a webpage about the computer lithium battery freezing method before the date of the article, so I strongly suspect that this article is the starting point for all notebook lithium battery frozen legend.

The other most important detail is not in the text, but in the comments below the text. Responsible forwarders also copy this important comment: After the freezing process, the battery was tested seven times in total. The first five times of battery power supply were more than one hour, significantly higher than the level before freezing. The sixth power supply began to fully recover to the state before freezing. Therefore, recovery after freezing can only be maintained for a short period of time.

Careful search on the Internet will reveal that there are many posts that announce the failure of the experiment (including a lot of laymen who are refrigerated rather than frozen). Posts that announce the success of the experiment and provide experimental data all have a common phenomenon, that is, it is only useful in a short period of time after freezing, and then it will not work, not only the lithium battery of a laptop, but also the lithium battery of a mobile phone. For example, in 2007, another article called "Mobile phone old battery can be repaired with a refrigerator? "The original article from Hangzhou's "Urban Express", pay attention to no, the frozen battery call for the map is from this article. This article was copied by netizens 1600 times, which makes me have great effort to find the original version. I don’t know if it is the minimum morality to mark the original author when reprinting?)

In addition to the battery core, a notebook lithium battery has other components, that is, some control circuits and chips, used to determine the battery's charging status, such as protecting the battery, not allowing you to overcharge and explode it, for example. Do not let you completely discharge the battery. This is because completely illuminating all of the electricity will permanently damage the battery compartment. Therefore, the protection circuit will automatically cut off all contact with the outside world before the battery is below the warning line. The newly purchased lithium battery requires deep charge and discharge when it is used for the first time, in order to allow the protection system to calibrate the parameters. (Of course, don't charge and discharge frequently in the future, it will be a long life.)

It has been said that long-term freezing is actually a process of forced deep discharge, and can be put to the extent that those protection lines are also ineffective. I strongly suspect that freezing actually disturbs these parameters, allowing the battery to save the last force for several times in violation of safety regulations, at the cost of permanent damage inside the battery. Of course, your battery is almost gone, and you don't care about suffering more.

I just posted a guess on the Internet yesterday, and some people questioned my guess. Ok, I don't know the principle. It is entirely possible that it is wrong. I also went online to search for the principle. The results of the search were even more confusing. With my years of experience in learning science and reading science fiction, those explanations sound more like science fiction than science, and I will not repeat them.

But the principle is unknown and does not prevent us from summarizing the data to draw conclusions. I know that many readers who are impatient have the habit of skipping large paragraphs and directly looking at the conclusions. So what is the result of this article, is the freezing method really effective? For the effect of the freezing method, I think of four words: returning light.

All in all, there is no practical value. One side is to spend a thousand or two dollars to buy a new one, one side is frozen for three days and then can only be used five times, you will not really be so tricky? Of course, I will finally need to emphasize it again. Here is the lithium battery that will be scrapped from the resurrection notebook (which may also include mobile phones). What we are saying is that the resurrection is not a collection, nor is it a battery of another variety. If it is a nickel-metal hydride battery or a nickel-cadmium battery, it will work in some cases because of the different principles. I am not talking about the button battery on your watch. Well, the data is not enough to judge.

At present, lithium batteries for mobile phones are classified into two types, lithium ion and lithium polymer. The cathode materials of the two batteries are the same, generally

All are lithium cobalt oxide (the ternary material and lithium iron phosphate are currently not available in mobile phone battery products), the difference is mainly

The lithium ion battery electrolyte is lithium hexafluoro phosphate, and the lithium polymer battery electrolyte is a solid polymer. Basic polymer battery

All the above are Sony Ericsson's batteries. In general, polymer batteries discharge more evenly and have better safety performance, but the cost ratio

Higher.

The charging precautions for the two lithium batteries are basically the same. Then I will focus on the safety features of lithium batteries. Since the lithium battery itself does not have overcharge protection, that is, overcharge is very likely to cause an explosion, all battery manufacturers will install a circuit control chip inside the lithium battery, and automatically power off immediately after overcharging. The safe temperature of lithium battery is about 180 degrees. Exceeding this temperature is extremely prone to explosion.

So how do you charge the battery when you buy a new mobile phone? Because any lithium battery must be safely tested before leaving the factory, the process is equivalent to activation, so that lithium ions in the cathode material can be freely accessed and there is no lattice collapse. Therefore, the battery to the ordinary consumer's hand is strictly tested and activated, do not worry about the activation state.

Now the first three times of the Internet has been circulated for 12 hours. The earliest mobile phone batteries were nickel-metal hydride batteries, such as the Nokia 3310. Nickel-metal hydride batteries do not need to be activated, and the battery itself has a memory effect, so in order to make electricity

The best performance, often requires the user to charge to the fullest, and then completely discharge the power (voltage from 1.2v to 1.0v), which can prevent memory effects. If the charging time is short, the battery is not completely excited.

Live, 1000mAh battery may only charge 900mAh, which has a great impact on battery efficiency and battery life itself.

What happens to the same method used on lithium batteries? Since the crystal characteristics of lithium cobaltate are different from those of nickel hydroxide, lattice collapse is more likely to occur than nickel hydroxide. Therefore, if the overcharge time is too long during the charging process,

It is easy to invalidate the space activity of lithium cobaltate, and charging will inevitably lead to an increase in temperature. First, it has a great influence on the positive electrode material, and may also cause danger. Because of this, in the process of using lithium battery, we must not use up the battery to recharge, so lithium cobalt oxide will be seriously invalid, and the life is shortened. The correct way is not to wait until the battery is almost empty before charging, and the battery indicates that the charging is completed and the power is removed immediately.

The charging method used on the mobile phone, the most appropriate is: the line charge in the off state, when the battery is full, immediately unplug the power, and then use it.