It’s not all smooth sailing. Interpreting the current research status of 18650 lithium 3.7 battery

　　Since its inception, 18650 lithium 3.7 battery have been widely used due to their excellent electrical properties. But its development is far from stopping. The main drawbacks of 18650 lithium 3.7 battery are the following:

　　(1) Safety needs to be further improved. Since the electrolyte of 18650 lithium 3.7 battery uses flammable organic solvents and corrosive electrolyte salts, the electrolyte easily reacts on the surface of the highly oxidized cathode material to produce flammable gases during overcharging. The internal pressure rises, causing the battery to bloat and Liquid leakage and other phenomena can cause corrosion and damage to electrical appliances; during discharge, lithium dendrites can easily form on the surface of the negative electrode and pierce the separator, causing an internal short circuit in the battery, causing the internal temperature of the battery to rise sharply and causing an explosion. Safety issues greatly limit the application fields of 18650 lithium 3.7 battery.

　　(2) Battery cost is high. Mainly including: the widely used LiCoO2 cathode material is expensive; the purification of the electrolyte system is difficult, and the development of a new generation of electrolytes has been a common call for people in the industry.

　　(3) Large current charging and discharging are not suitable for existing power tools. Due to the use of organic electrolyte system, the internal resistance of the battery is large. The general discharge current is 0.5mA×cm-2, and the maximum is 2~4mA×cm-2. It is only suitable for small and medium current electrical appliances. Currently, the world's scientific and technological and industrial circles are working hard to develop 18650 lithium 3.7 battery and related technologies, constantly developing new products, expanding market scope, and constantly researching new lithium-ion battery materials to improve battery performance and reduce battery costs.

　　(4) The specific energy of existing 18650 lithium 3.7 battery is too low and cannot meet the application requirements of pure electric vehicles. At present, the specific energy of 18650 lithium 3.7 battery actually used commercially in the industry is only about 100Wh/kg. Such a low specific energy has led to the weight of the battery reaching 1 ton in order to meet the travel requirements of electric vehicles. For example, the pure electric battery piloted in Hangzhou in 2011 The battery used in the car is a lithium iron phosphate battery produced by Zotye Holdings and Haima Automobile Company. The battery weight of each car reaches 1 ton, which means that half of the energy during the journey is actually running with the battery on its back.

　　The future direction of lithium batteries

　　Although 18650 lithium 3.7 battery have achieved great commercial success, their development has not been smooth sailing. Opportunities and challenges coexist for 18650 lithium 3.7 battery and their researchers. According to the research and development of new lead-acid batteries in 2011 and the integration of my country's lead-acid battery industry, Japanese researchers have included the application of sodium-sulfur batteries in energy storage, as well as the lithium-sulfur batteries and lithium air that research institutes and schools have paid attention to in recent years. The development of batteries will have an impact on the current lithium-ion market. In particular, research reports indicate that a recent major technological breakthrough by U.S. researchers may be that lithium-air batteries have the potential to achieve a major leap in battery technology because they reduce weight and complexity compared to standard batteries. . While a standard battery has all its components stored internally, lithium-air batteries use oxygen from the air. The biggest problem with this technology, however, is that the active oxygen reacts with other battery components. Researchers have discovered an electrolyte material that does not react with oxygen, allowing batteries to remain stable after multiple charges and discharges. According to researchers' estimates, the battery can theoretically store 10 times the power of existing 18650 lithium 3.7 battery on the market.

　　For lithium-ion battery researchers, the top priority should be to further reduce raw material costs and improve battery cycle performance and stability through process innovation. From the perspective of technological development direction, the following three aspects should be given great attention:

　　(1) Develop large-capacity lithium-ion power batteries for electric vehicles;

　　(2) Develop and use new high-performance electrode materials, especially the development of high-performance cathode materials;

　　(3) Further reduce the cost of 18650 lithium 3.7 battery and improve the safety performance of batteries. For the commercial application of 18650 lithium 3.7 battery, it is necessary to adjust the operation management model in the industry to meet the requirements for producing high-standard batteries. In fact, this It is also what China, which accounts for 40% of the world's cathode material sales, needs the most attention and development. This is just like why China is a manufacturing country rather than a manufacturing power. This phenomenon also exists in China's lithium-ion battery market, and it is quite serious.

Read recommendations:

Lithium-ion battery GN200 222wh

Aqueous solution lithium battery system.LR927 battery

CCS certification standards for lithium batteries for electric ships

24v lifepo4 battery pack

lithium battery 18650