Analyze high-energy technology research on lithium batteries

Lithium battery high-energy technology analysis Recently, GGII visited more than 50 companies, participated in multiple forums and exchanges, and found a major breakthrough in lithium battery high-energy density technology. The development path of high energy density includes: high-voltage anode materials, high-g-capacity anode materials. High-voltage cathode materials generally refer to cathode materials with an applied voltage higher than 4.2v. Lithium cobalt acid and lithium manganese acid are all high-voltage materials. At the same time, the commercial applications of high-voltage lithium cobalt oxide have been very mature, many of which are used in high-end digital products, and their energy density is higher than that of ordinary ternary batteries. At present, the voltage of a high-voltage lithium cobalt oxide battery is generally 4.35v. In the next 3-5 years, 4.4v and 4.5v high-voltage lithium cobalt acid batteries may be used on a large scale. The three kinds of high voltage cathode materials are rarely used, in the basic research stage. However, the ternary high-voltage cathode material may be the breakthrough point for the energy density of 300Wh/kg in the future. Now the gram capacity of the three NCM811 materials has exceeded 180mAh/g, high pressure may be completed after coating, and its gram capacity will have further progress (high pressure materials are equivalent to no active lithium activation at low pressure, and more Use more materials). However, there are still many technical problems with ternary materials under high pressure, and the stability of the material itself has not been resolved. The charging potential of lithium manganate cathode material can reach 4.7V, and the lattice structure is very stable. At present, the energy density of lithium manganate batteries is 150Wh/kg, which is higher than that of lithium iron phosphate batteries. Lithium manganate has a stable crystal structure and excellent thermal stability. The safety of lithium manganate batteries is very high. The lithium manganate-lithium titanate battery system has a good application prospect in the field of fast charging. Because of its capacity close to theory, lithium iron phosphate is difficult to activate more lithium after high pressure, and the effect is very limited. However, lithium iron manganese (vanadium) phosphate and lithium iron silicate have high energy density, which is a hot area of u200bu200bresearch by many research institutions and companies. The lithium iron silicate molecule contains two kinds of lithium ions, and the theoretical gram capacity can reach 332mAh/g. High-voltage cathode materials need to be matched with high-voltage electrolyte to make the entire battery system work well. In order to make the electrolyte work smoothly in a high-pressure environment, it is necessary to improve the oxidation resistance of the solvent and block the direct contact between the positive electrode and the electrolyte. Anti-oxidation methods of advanced electrolytes include fluorinated solvents, which are difficult to apply on a large scale due to their high prices. Other new anti-oxidant solvents, such as ionic liquids, have excellent ionic conductivity and anti-oxidation capabilities, and are excellent solvents for lithium batteries, but they are currently expensive and difficult to implement on a large scale. Methods to prevent direct contact between electrolyte and electrolyte include anode coating and anode film-forming additives. There are many studies on the coating of anode materials and additives, and the effect is very significant, which is an important method for the progress of anti-oxidation research in the future. The large-scale development and application of ternary materials are relatively late, and there is still much room for improvement in energy density. At present, mainstream material manufacturers have been able to reach the level of 180mAh/g, while the theoretical output of the three high-nickel materials can reach 270mAh/g, and there is still a lot of room for development. At present, high-capacity ternary materials have the characteristics of sensitivity to water, low efficiency, and poor circulation. With the advancement of process technology, these problems can still be solved, and lithium-rich anodes are also a hot topic for discussion by many research institutions and companies. On the other hand, the silicon anode material can greatly increase the capacity of the negative electrode. The cathode material has always been graphite, and the graphite anode technology is now very mature, and the actual capacity is now very close to the theoretical capacity. In order to increase the cathode gram capacity, we must choose other materials. 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 post: Do you know the difference between lead-acid batteries and lithium batteries?