Development trend of lithium-ion battery technology

At present, in terms of technical routes, the industry’s common classification of lithium-ion batteries is lithium cobalt oxide batteries, lithium manganese oxide batteries, lithium iron phosphate batteries, and lithium titanate batteries. Among them, the industrialization of lithium cobalt oxide batteries is the most mature and has been widely used in small mobile devices such as mobile phones and notebook computers; lithium manganate battery has become a potential electric vehicle battery with its advantages of low cost and high performance, and has a certain degree of maturity in Japan; lithium iron phosphate battery has become the most popular energy storage and electric vehicle battery with its advantages of long life, low cost and high safety, especially in China; the domestic lithium titanate battery has not overcome the process problem. In the world, only Toshiba of Japan has successfully developed this battery and applied it to electric bicycles.

For lithium cobalt oxide batteries, the future development trend will be to improve the stability of the material structure and improve the safety of the battery. According to the current research results, in the future, we will mainly use Mn, Al, Ni and other elements to replace part of the Co element to reduce the amount of Co, improve the stability of the material, and reduce the cost. Or doping with other elements such as Mg and Zr can stabilize the crystal structure of the material and improve the structural stability of the material. For lithium manganate batteries, the main technological development trend is to study how to solve the problem of rapid battery capacity decay. In the future, from the perspective of the dissolution of manganese ions, various manufacturers will study how to avoid the transformation of the material structure into a tetragonal structure with low symmetry and enhanced disorder, suppress the generation of HF in the electrolyte, and improve the problem of excessive capacity decay and material instability in lithium manganate batteries. Surface modification to effectively inhibit the dissolution of manganese and the decomposition of electrolyte; doping to effectively suppress the Jahn-Teller effect during charging and discharging, and to further improve the electrochemical performance of the material, will become one of the research directions for the modification of spinel-type lithium manganate in the future.

For lithium iron phosphate batteries, its future development tends to solve technical problems in the preparation, charging and discharging of lithium iron phosphate materials:

The preparation of lithium iron phosphate materials is difficult, the particle growth is difficult to control during the high-temperature synthesis process, and the uniformity of the particle size of the material is poor, and at the same time, Fe2+ is easily oxidized to Fe3+, resulting in Li3Fe2 (PO4)3 or LiFe(P2O7) impurities. It is necessary to study liquid phase preparation and low-temperature sintering technology to improve the consistency of the material; lithium iron phosphate batteries are highly polarized during charging and discharging, and the battery rate performance is poor, and generally cannot exceed 5C discharge. In the future, it is hoped that this problem can be solved to a certain extent through nanometerization, but the nanometerization process is more complicated, and nanometer lithium iron phosphate will face the problem of high cost.

The development of anode materials for lithium-ion batteries is relatively mature. In commercial applications, graphite-like carbon materials are relatively mature. In recent years, hard carbon, lithium titanate (Li4Ti5O12), alloys and other materials have also become research hotspots. Graphite carbon materials have outstanding performance in terms of safety and cycle life, and are cheap and non-toxic. They are the most common negative electrode materials; due to the problems of low first efficiency, low compaction density, and immature technology, hard carbon materials have not yet entered the stage of large-scale commercialization. Related fields in China are still in the experimental stage, and there are not many companies that have achieved industrialized sales. The more famous one is Kureha Chemicals of Japan; Lithium titanate is an embedded compound that has not been widely used in commercial applications, but Chinese foreign companies and research institutions have paid great attention to it; metals or metal compounds can solve the problem of low capacity of the negative electrode material, but will cause the mechanical stability of the material to decrease, thereby gradually pulverizing and failing, and ultimately leading to poor cycle performance of the battery. At present, improving the performance of alloy anode materials and improving the stability of electrochemical cycles are the focus of everyone’s attention, such as the use of nanomaterials to achieve this goal.

The barriers of isolation membrane technology are high, and the engineering technology of making holes and matrix materials are its main technical difficulties. At present, Japanese and American manufacturers occupy a monopoly position. For example, the three monopoly giants of Japan’s Asahi Kasei, Tonen Chemical, and Celgard of the United States each occupy 20% of the global market. In recent years, the quality of domestic membranes has gradually improved, but compared with Japanese and American products, the quality gap is still very large, and they are mostly used in the low-end lithium-ion battery market.

The main raw materials for the production of lithium battery electrolyte include solvents, additives and electrolytes. Solvents mainly include propylene carbonate, dimethyl carbonate, etc.; electrolytes include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, trifluoromethylsulfuric acid and so on. At present, the technical process of solvents and additives has become more popular, with sufficient production capacity and basically achieved localization, while the electrolyte technology is relatively complex and has the greatest impact on product performance. At present, the electrolyte with the best performance and the most used amount is lithium hexafluorophosphate. The technological research and development level, production and supply capacity, and price level of lithium hexafluorophosphate greatly affect the technological development level and output of downstream electrolytes and even lithium batteries. However, there are currently very few companies that have independent large-scale production of lithium hexafluorophosphate globally. The global suppliers with mass production capacity of lithium hexafluorophosphate are mainly Japanese companies. There are also a few companies in South Korea and China that have small-scale production capabilities.For example, TYCORUN ENERGY lithium iron phosphate battery ups are also excellent lithium iron phosphate batteries that I know. If you are interested, you can click on the link on the right:

Development trend of lithium-ion battery technology