Do you know the direction of the final development of lithium batteries?

The advantages of solid-state polymer lithium batteries: the possibility of leakage is relatively small, and the outer packaging can be made of laminate soft pack material, which is conducive to the realization of the thin film of the battery. The shape of the battery has a large degree of freedom and the energy density is greatly improved. Disadvantages: Due to the use of gel-like electrolyte, lithium ion conductivity is relatively poor, it takes a long time to charge, and the rate is worse than that of liquid electrolyte. However, the current technology, after the improvement of the polymerization process, high-end electrolyte and additives make the cycle life and discharge rate increase very quickly, which is not much different from that of liquid batteries. The subsequent technological development of polymer lithium batteries will develop towards all-solid batteries, solid electrolyte materials and additives. At present, the performance of polymer batteries has not reached the level of solid batteries. The future goal of solid battery energy density: 400Wh/kg, 3000 cycles life (10 years), rate performance, capacity and safety have been greatly improved. The exploration of new battery materials lies in the non-volatile, flame-retardant next-generation electrolyte materials and additive ion electrolytes to improve electrochemical and thermal stability. The additives make the battery's heat dissipation and electrical conductivity not affected by solids, reaching or exceeding that of liquid electrolytes. The level of electrical and thermal conductivity. In order to enter the solid lithium battery, the industry is currently developing solid polymer electrolytes using ion-conducting polymers and ceramics. However, if the solid polymer electrolyte material uses polyethylene (Polyethyleneoxide polyethylene oxide) polymer with the highest ion conductivity at present, the ion conduction of anions will hinder the movement of lithium ions, so it will affect the effectiveness of the output power. The value of ion conductivity is low. The solid polymer electrolyte successfully developed by Japanese scientists is a polyethylene glycol (PolyethyleneglycoD acid ester compound). It has a structure in which boron atoms, which have the function of fixing anion, are introduced in the form of a borate compound that does not hinder the movement of polyethylene polymers. Compared with the carbonic acid polymer that has been studied before, it can achieve more than 3 times the effective lithium ion conductivity at room temperature (20℃). The new generation of large-capacity lithium battery using solid electrolyte, the so-called all-solid battery recently It started to attract attention. This is because it can also ensure safety and achieve long life while increasing its energy density. For electric vehicles and customized large-scale lithium-ion rechargeable batteries, ensuring safety is the most important. The use of organic The traditional lithium-ion rechargeable battery with electrolyte may cause the electrolyte to heat up due to abnormalities such as overcharging and internal short-circuit, and there is a danger of spontaneous combustion or even explosion. The all-solid-state battery that replaces the organic electrolyte with a solid electrolyte is safe The performance can be greatly improved. In addition, because the diffusion rate (ionic conductivity) of lithium in the solid state is higher than that in the liquid electrolyte in an ideal state, it is theoretically believed that it can achieve a higher output. Moreover, the solid-state battery pack includes its manufacturing It may achieve characteristics that break through the existing battery concept. For example, because there is no need to enclose liquid, the battery exterior can be simplified, so that large-area cells can be manufactured in a roll-to-roll manner. Further, it is also Several layers of electrodes can be stacked and connected in series in the cell to make a 12V or 24V high-voltage cell, etc., so that previously impossible batteries can be realized. Large batteries and ultra-large lithium batteries for electric vehicles and customized power storage, and The demand for small batteries for non-mainstream portable devices so far has soared. Therefore, changes in battery characteristics are required to make a major change in the direction of research and development. In particular, the safety and service life of the battery are more than the existing lithium-ion rechargeable batteries. Strict requirements. Among them, safety goes without saying, solid-state batteries have distinct advantages; and in terms of extended service life, the cycle life characteristics of solid-state batteries are inherently excellent. High voltage resistance: In addition to being safer and more reliable than current lithium-ion rechargeable batteries Longer service life and improved energy density are also the development theme of solid-state batteries. One of the reasons that solid-state batteries can have new energy density features is the spaciousness of the potential window* of the solid electrolyte. In contrast to the existing traditional organic electrolysis When the battery voltage is close to 4V, the electrolyte starts to analyze, so it is difficult to increase the upper limit of the battery voltage. Potential window: The voltage range in which the electrolyte composed of solvent and salt does not undergo redox reaction. It depends on the solvent, Salt and electrode materials. At present, in order to increase the capacity, the negative electrode of lithium-ion rechargeable batteries is prepared to be changed to materials such as silicon with high current capacity. Although the high-capacity positive electrode material corresponding to the negative electrode is equally important, it has not been found to be expected to support higher current Capacity of the cathode material. Therefore, in terms of cathode material, the so-called 5V cathode material with the same current capacity and high voltage to increase the energy density will be used as the cathode material. aims. But even if the 5V voltage type cathode material is used, the traditional organic electrolyte will still analyze, and the battery voltage still cannot be increased. The use of a solid electrolyte with a wider potential window can make a 5V positive electrode a viable solution. Because the solid electrolyte is a solid, when the interface between the electrode material and the electrolyte reacts, the further reaction is difficult to proceed, which is more difficult to analyze than the organic electrolyte, so the potential window is higher. In addition, solid electrolytes are expected to play an important role in the realization of next-generation batteries such as lithium sulfide (Li-S)* and lithium-air (Li-air)* batteries that have attracted attention as lithium polymer rechargeable batteries. Lithium sulfide batteries use sulfur (S) materials as the positive electrode. If an organic electrolyte is used, sulfur will dissolve in it. If solid electrolytes can be used, this problem does not exist. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.