Research and characteristic analysis of key materials for all solid-state lithium-ion batteries

With the rapid development of society, our all-solid-state lithium-ion batteries are also developing rapidly, so do you know the detailed analysis of all-solid-state lithium-ion batteries? Next, let the editor lead you to learn more about the relevant knowledge. As the most potential electrochemical energy storage device, all-solid-state lithium-ion batteries have received extensive attention in recent years. With the improvement of comprehensive technical indicators such as cycleability and safety, the application market for solid-state secondary lithium-ion batteries will gradually expand, and all-solid-state lithium-ion batteries are expected to become the dominant technology route for next-generation power lithium-ion battery manufacturers. The advantages of all-solid-state secondary lithium-ion batteries In recent years, with the rise of electric vehicles and the urgent demand for large-scale energy storage equipment for renewable energy generation, the research on lithium-ion batteries has heated up again, safety, large capacity, high power and long life Secondary lithium ion batteries have become the focus of attention. As a new form of lithium ion battery, solid secondary lithium ion battery fundamentally has the advantage of high energy density of lithium ion battery. In addition, all solid-state secondary lithium-ion batteries also have the following advantages: (1) High safety performance: Since the liquid electrolyte contains flammable organic solvents, the temperature suddenly rises when an internal short circuit occurs, which can easily cause combustion or even explosion. It is necessary to install a safety device structure that can withstand temperature rise and short-circuit, which will increase the cost. But it still cannot completely solve the security problem. Tesla (Tesla) claims to be the best BMS in the world, and this year alone caused two serious ModelS fire accidents in our country. Therefore, all solid-state lithium secondary batteries based on inorganic solid electrolytes are expected to have high safety. (2) High energy density: The energy density of lithium-ion batteries currently on the market is as high as 260Wh/kg, and the energy density of lithium-ion batteries under development can reach 300-320Wh/kg. Regarding all solid-state lithium-ion batteries, if lithium metal is used as the negative electrode, the battery energy density is expected to reach 300-400Wh/kg, or even higher. It is expected that all solid-state secondary batteries will achieve higher power density. The solid electrolyte uses lithium ions as a single carrier and has no concentration polarization, so it can work under high current conditions to increase the power density of the battery. (3) Long cycle life: The solid electrolyte is expected to prevent the continuous formation and growth of the solid electrolyte interface film and the problem of lithium dendrites piercing the separator during the charging and discharging process of the liquid electrolyte. This may greatly improve the cycle performance and use metal lithium ions. The service life of the battery. (4) Wide operating temperature range: If all solid-state lithium-ion batteries use inorganic solid electrolytes, the maximum operating temperature is expected to increase to 300°C or even higher. At present, it is necessary to improve the low temperature performance of large-capacity all-solid-state lithium-ion batteries. The specific operating temperature range of the battery is importantly related to the high and low temperature characteristics of the electrolyte and the interface resistance. (5) Wide electrochemical window: The electrochemical stability window of all solid-state secondary lithium-ion batteries is very wide, which can reach 5V, which is suitable for high-voltage electrode materials and is beneficial to further increase the energy density. Currently, thin-film lithium-ion batteries based on lithium nitride lithium phosphate can operate at a voltage of 4.8V. (6) Advantages of flexibility: The solid secondary lithium-ion battery also has the characteristics of compact structure, adjustable scale, and great design flexibility. Solid-state batteries can be designed as thin-film batteries with a thickness of only a few microns to drive microelectronic devices, or they can be made into large-size batteries used to drive electric vehicles, grid energy storage and other fields. In these applications, the shape of the battery can also be designed according to specific requirements. Research on the key materials of all solid-state lithium-ion batteries ●Polymer solid electrolyte: polymer solid electrolyte (SpE), due to its relative, is composed of polymer matrix (such as polyester, polymerase and polyamine, etc.) and lithium salt (such as LiClO4) , LiAsF4, LipF6, LiBF4, etc.). High quality, light weight, good viscoelasticity and excellent processing properties have attracted widespread attention. ●Oxide solid electrolyte: According to the material structure, oxide solid electrolyte can be divided into two types: crystal and glass (amorphous). Crystalline electrolytes include perovskite type, NASICON type, LISICON type and garnet type. The research hotspot of glass oxide electrolyte is the LipON type electrolyte used in thin film batteries. ●Oxide crystalline solid electrolyte: The oxide crystalline solid electrolyte has high chemical stability and can exist stably in the atmosphere, which is beneficial to the large-scale production of all solid-state batteries. The current research focus is to improve the room temperature ionic conductivity and its relationship with the electrode. There are two aspects to the compatibility of the electrode. The most important method to improve conductivity is element replacement and heterogeneous element doping. In addition, the compatibility with the electrode is also an important issue that limits its application.