Analyze the principle and maintenance of lithium batteries

The principle and maintenance of lithium battery This article was originally written specifically for the problem of using lithium batteries in notebook computers, but it also applies to the use of lithium batteries in mobile phones, so it may be helpful to learn. Most of this article is a systematic excerpt, and the publisher has made a brief correction. I hope the moderator will not delete this article. How is the maintenance of the lithium battery of our love machine correct? This problem has been plagued by many loyal mobile phone users, including me. After consulting some information, I recently had the opportunity to consult with a PhD student in electrochemistry. Now write down some relevant common sense and relevant experience that you have recently acquired. The cathode material of lithium batteries is usually composed of lithium active compounds, while the anode material is carbon with a special molecular structure. The commonly used anode material is LiCoO2. When charging, the new potential of the battery pole forces the compound of the positive electrode to release lithium ions, which are embedded in the carbon arranged in a sheet structure. When lithium ions are discharged, the lithium ions are separated from the layered carbon and combined with the anode compound. Electric current occurs in the movement of lithium ions. Although the principle of chemical reaction is very simple, in actual industrial processing, more practical issues must be considered: positive electrode materials need additives to maintain the activity of repeated charging and discharging; negative electrode materials should be planned at the molecular structure level to accommodate more More lithium ions; the electrolyte between the positive and negative electrodes must not only be stable, but also have good conductivity to reduce the internal resistance of the battery. Although lithium batteries rarely have the recall effect of nickel-cadmium batteries (used through crystallization), they rarely have the same effect in lithium batteries. However, due to various reasons, the capacity of lithium batteries will still decrease after repeated charging. The first is the modification of the anode and cathode materials themselves. From a molecular level, the cavity structure containing lithium ions on the positive and negative electrodes will gradually collapse and be blocked. From a chemical point of view, it is the passivation of positive and negative materials, and there are side-uses to appear stable other compounds. Physically, the positive electrode material gradually falls off, which ultimately reduces the amount of free movement of lithium ions during battery charging and discharging. Overcharging and discharging cause permanent damage to the electrode of the lithium battery to the molecular level. It can be intuitively known that the anode carbon emission will cause the excessive release of lithium ions and the collapse of the layer structure, and overcharging will force too much lithium ions into it. The structure of the cathode carbon, and some lithium ions can no longer be released. This is why lithium batteries are often equipped with charge and discharge control circuits. Improper temperature can cause unwanted compounds in other chemical reactions in lithium batteries, so many lithium batteries are equipped with maintenance temperature control diaphragms or electrolyte additives between the positive and negative electrodes. When the battery temperature rises to a certain level, the composite membrane pores are closed or the electrolyte is denatured, and the internal resistance of the battery increases until the circuit is disconnected and the battery is no longer heated to ensure the battery's normal charging temperature. Can deep charging increase the actual capacity of a lithium battery? Experts told me unequivocally that it didn't make sense. They even said that according to their common sense, the so-called activation of the first three complete charges is not necessary. But why do many people change the capacity of battery information after deep charging? We will talk about it later. Lithium batteries are generally equipped with a processing chip and a charging control chip. In the process, the chip has a series of registers, capacity, temperature, ID, charging status, discharge time and other values. These values u200bu200bgradually change with the application. Personally, I think that the important functions of the practice charge and discharge once a month or so. The instructions in the application program should correct the improper value of these registers, so the battery charge control and nominal capacity conform to the actual situation of the battery. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Power lithium battery should start with electric bicycles