As the "heart" of electric vehicles, power batteries have attracted as much attention as the current hot new energy vehicles. Among them, lithium-ion batteries are favored by the new energy automobile industry because of their high energy density, low self-discharge rate, high cycle efficiency, and long cycle life, and the market has great potential for development. However, the current lithium-ion battery technology is not yet mature, and the problem of unstable safety still exists. Coupled with the frequent accidents of "irregular battery fires" that have been stimulating the nerves of consumers, the development of solid-state battery technology may become a new choice to solve the safety problem of electric vehicles. "The cost of lithium-ion batteries currently used is relatively high, and the technology is immature, and there are many safety hazards in the lithium-ion batteries produced." Wang Zhenbo, a professor at Harbin Institute of Technology, said. It is understood that accidents of large-scale power batteries have occurred frequently in recent years, largely due to the use of liquid electrolytes inside the batteries.Please check:https://www.aimeno.com/lithium-battery/215.html "Whether it is safe or not is very important for lithium-ion battery energy storage." Li Liangliang, an associate professor at the School of Materials Science and Technology of Tsinghua University, emphasized, "Currently commercial lithium-ion batteries on the market generally use organic liquid electro-hydraulic. Leakage of liquid, causing environmental pollution." The fire of lithium-ion battery equipment in Yeongam, South Korea two months ago seems to confirm this statement. "The liquid organic electrolyte currently used is flammable and explosive. Replacing the liquid electrolyte with a solid electrolyte is one of the most effective methods we recognize to improve the safety performance of lithium batteries." Associate researcher at Qingdao Institute of Bioenergy and Process Technology, Chinese Academy of Sciences Dong Shanmu said. Solid electrolyte is not flammable and does not produce liquid electrolyte, so it is non-corrosive, which is an effective way to solve the problem of battery safety, and it is also in line with the trend of future battery development. High safety is the basis and prerequisite for the application of energy storage batteries, and solid state is the best way to solve the safety of secondary batteries. Solid-state lithium batteries have entered the stage of accelerating global layout and research and development, and many famous institutions are developing solid-state lithium batteries. At present, many battery and automobile manufacturers, including Germany's Volkswagen, South Korea's Samsung, Japan's Toyota, and my country's CATL, have increased investment in solid-state battery research and development, and some batteries have entered the stage of loading and testing. Although the prospects are promising, due to various technical and process problems, the road to the development of solid-state batteries is by no means smooth. First, there is a lack of efficient electrolyte material systems. At present, solid-state battery materials are developing rapidly, but their comprehensive applications are relatively lacking. As the core material of solid-state batteries, breakthroughs have been made in the single index of solid lithium-ion conductors, but the overall performance cannot meet the needs of large-scale energy storage. The solid-state electrolytes used in solid-state batteries today generally have performance shortcomings, and there is still a big gap from the requirements of high-performance lithium-ion battery systems. Secondly, the interface treatment of solid-state electrolytes and electrodes is also a major problem currently facing solid-state batteries. In the solid electrolyte, the lithium ion transport resistance is very large, and the contact area of the rigid interface with the electrode is small, and the change of the electrolyte volume during the charging and discharging process easily destroys the stability of the interface. In addition, in a solid-state lithium battery, in addition to the interface between the electrolyte and the electrode, there are complex multi-level interfaces inside the electrode. Electrochemical and deformation factors will cause contact failure and affect battery performance. Third, unsatisfactory stability during long-term use is also a bottleneck for the development of long-life energy storage solid-state batteries. The structure and interface of solid-state batteries will degrade over time during service, but the mechanism of the impact of degradation on the overall performance of the battery is not yet clear, and it is difficult to achieve long-term application. To build a high-performance solid-state battery needs to start from two aspects, one is to build a high-performance solid-state electrolyte, and the other is to improve the compatibility and stability of the interface. For solid-state batteries, we need to conduct research from the most basic materials, interfaces, monomers, and finally to the final system module. Only by fundamentally solving the key material and interface problems can we carry out systematic process research to meet the needs of single batteries. performance requirements.Please check:https://www.aminobattery.com/lithium-battery/203.html In the face of continuous challenges in the development process, various new technologies "contend among a hundred schools of thought", and some solid-state battery technologies have made the latest breakthroughs. For example, in terms of solid electrolyte materials, the industry has found that solid-state batteries based on garnet-structured lithium lanthanum zirconium oxide (LLZO) solid electrolyte systems have excellent cycle performance and rate performance, and it has therefore become a major technical hotspot. LLZO is an excellent filler that can improve the performance of polymer-based composite solid-state electrolytes. The LLZO-based solid-state battery retains 81% capacity after 1000 cycles. Dong Shanmu told reporters another idea of electrolyte materials - "rigid and soft", using rigid polymer skeleton and inorganic particles to fuse with flexible polymer ion transport materials. "Through the Lewis acid-base interaction between polymers and polymers, and between polymers and inorganic particles, new channels can be created for lithium ion transport and the overall performance of the electrolyte will be greatly improved." The research hotspots of interface treatment mainly focus on In terms of interface design and modification layer, the current gelation interface design has achieved good results. The interface is modified by a gel-state polymer to increase the contact area while buffering the volume effect during cycling. After 300 cycles at room temperature, there is basically no degradation. This structural design better improves battery performance. . In addition to solid-state electrolytes and interfaces, the integrated design of solid-state batteries is also very important. Because for different fields such as energy storage and new energy vehicles, targeted battery structure design is required. In general, the research on solid-state batteries is currently more academic. In terms of industrialization, some key technologies cannot be obtained because they involve the core technologies of various enterprises, so further research is needed on technologies based on engineering applications.