How far have lithium batteries been studied?

Do you know lithium batteries? With the rapid development of society, our lithium batteries are also developing rapidly, so do you know the detailed introduction of lithium batteries? Next, let the author lead everyone to know the relevant knowledge in detail. With the process of economic globalization and the ever-increasing demand for energy, finding new energy storage devices has become a focus of attention in new energy related fields. Lithium battery (LIB) is currently the battery system with the best overall performance. It has the characteristics of high specific energy, high cycle life, small size, light weight, no memory effect, and no pollution. It has rapidly developed into a new generation of energy storage power supply. Power support in the fields of information technology, electric and hybrid vehicles, aerospace, etc. Nowadays, electric vehicles are becoming more and more popular in the market, but the long charging time is also prohibitive. Traditional fuel vehicles can extend the range by 500 kilometers with full fuel in just 5 minutes, while the most advanced electric vehicles currently on the market need to 'wait' for an hour to recharge to achieve the same range extension effect. The development of large-capacity lithium batteries with fast charging capabilities has always been an important goal of the electric vehicle industry. Using graphite or petroleum coke and other carbonaceous lithium intercalation compounds instead of metallic lithium as the negative electrode will cause the battery voltage to drop. However, due to their low lithium insertion potential, the voltage loss can be reduced to a minimum. At the same time, choosing a suitable lithium intercalation compound as the positive electrode of the battery and choosing a suitable electrolyte system (which determines the electrochemical window of the lithium battery pack) can make the lithium battery pack have a higher working voltage (-4V), which is much higher than that of the aqueous solution. System battery. At present, the scale of the world's lithium battery market is mainly reflected by Japan. In 1995, Japan's lithium battery market accounted for 88.06% of the world's lithium battery market. With the rapid development of portable electronic devices, the market scale of lithium batteries is also expanding. The application of lithium batteries not only develops towards small and light-weight small electrical appliances, but also begins to develop towards large-scale electric equipment. In a lithium battery, energy enters and exits the battery through the chemical reaction between lithium ions and electrode materials, so the conductivity of the electrode material to lithium ions is the key to determining the charging speed; on the other hand, the electrode material per unit mass or volume contains how much lithium ions It is also an important factor. The lithium battery pack adopts a non-aqueous electrolyte system, and the lithium-intercalated carbon material is thermodynamically unstable in the non-aqueous electrolyte system. During the first charge and discharge process, the reduction of the electrolyte will form a solid electrolyte interphase (SEI) film on the surface of the carbon negative electrode, allowing lithium ions to pass but not allowing electrons to pass, and making the electrode active materials of different charged states. In a relatively stable state, it has a low self-discharge rate. Lithium batteries are composed of positive and negative electrodes, binders, electrolytes and separators. In industry, manufacturers mainly use lithium cobalt oxide, lithium manganate, Lithium nickel cobalt manganese oxide ternary materials and lithium iron phosphate are used as cathode materials for lithium batteries, and natural graphite and artificial graphite are used as anode active materials. Polyvinylidene fluoride (PVDF) is a widely used cathode binder , High viscosity, good chemical stability and physical properties. The recycling process of industrial waste lithium batteries mainly includes pretreatment, secondary treatment and advanced treatment. Since there is still some electricity remaining in the waste batteries, the pretreatment process includes deep discharge Process, crushing, physical sorting; the purpose of the secondary treatment is to achieve complete separation of the positive and negative active materials from the substrate. Heat treatment, organic solvent dissolution, lye dissolution and electrolysis are commonly used to achieve complete separation of the two The advanced treatment mainly includes two processes of leaching and separation and purification to extract valuable metal materials. The biological leaching method has low cost, high recovery efficiency, low pollution and consumption, and less impact on the environment, and the microorganisms can be reused However, it is difficult to cultivate high-efficiency microorganisms, the processing cycle is long, and the control of leaching conditions is a few major problems that this method requires. In the use of lithium-ion batteries, it should be noted that the battery will enter a dormant state after being placed for a period of time. The capacity is lower than the normal value, and the use time is also shortened. But the lithium-ion battery is easy to activate, as long as the battery can be activated after 3-5 normal charge and discharge cycles, and the normal capacity can be restored. Due to the characteristics of the lithium-ion battery, it is decided Because it has almost no memory effect. Therefore, the new lithium-ion battery in the user's mobile phone does not need special methods and equipment during the activation process. To charge the lithium battery, you should use a special lithium battery charger. The lithium battery is charged by ' 'Constant current/constant voltage' method, first charge with constant current, and change to constant voltage when it is close to the termination voltage. Overcharge and discharge of lithium batteries will cause permanent damage to the positive and negative electrodes. Overdischarge causes the structure of the negative carbon sheet to collapse. The collapse will cause the lithium ions to be unable to be inserted during the charging process; overcharging causes too many lithium ions to be inserted into the negative carbon structure, and some of the lithium ions can no longer be released. The charge amount is equal to the charge current multiplied by the charge time, and the charge control Under the circumstance of a certain voltage, the greater the charging current (the faster the charging speed), the lower the charging power. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: How to build a lasting Durable batteries: to reduce costs or extend life?