How to solve the bottleneck caused by batteries to new energy vehicles?

1. Why has the battery become the shackles of new energy? As we all know, the advantage of new energy vehicles is that they are more low-carbon and environmentally friendly than gasoline-fueled vehicles. It uses unconventional vehicle fuels as power sources, such as lithium batteries and hydrogen fuel. The application fields of lithium batteries are also very extensive, in addition to new energy vehicles, mobile phones, notebook computers, tablet computers, mobile power supplies, electric bicycles, power tools and so on. At present, mainstream new energy vehicles such as the world-renowned Tesla or the well-known domestic Xiaopeng Automobile, Weilai Automobile and BYD use lithium batteries. The lithium batteries used by these new energy vehicle manufacturers can be classified according to the cathode materials: lithium iron phosphate batteries, ternary lithium batteries (including NCA and NCM), lithium manganate batteries, lithium cobalt oxide batteries, nickel hydrogen batteries, titanic acid Lithium cell and so on. Among them, Tesla, BAIC E200/150, GAC Trumpchi GA5EV, Beijing Benz, BMW Brilliance 5 Series, Weilai Automobile, etc. all use ternary lithium batteries. And BYD, which once used lithium iron phosphate batteries, later turned to the ternary lithium battery camp. But whether it is a ternary lithium battery or a lithium iron phosphate battery, they cannot avoid the hidden dangers of flammability and explosion. Lithium is the most active metal in the world. Due to its active chemical properties, when exposed to the air, lithium metal will undergo a violent oxidation reaction with oxygen, so it is prone to explosions and combustion. In addition, redox reactions will also occur inside the lithium battery during the charging and discharging process. The explosion and spontaneous combustion are mainly caused by the accumulation of the lithium battery after heating, and it is too late to diffuse and release. Simply put, a large amount of heat will be generated during the charging and discharging of lithium batteries, which will cause the internal temperature of the battery to rise and the temperature unevenness between the single cells, which will cause the new energy of the battery to be unstable. In August of this year, Apple’s retail store in Amsterdam, the Netherlands, was temporarily closed due to an explosion of iPad batteries and release of potentially harmful substances into the air. The retail store had to evacuate consumers in the store temporarily. Before this, Samsung, Xiaomi, Huawei, etc. have also been exposed to mobile phone spontaneous combustion incidents. Many accidents have shown that when people are charging improperly or the ambient temperature is too high, it is extremely easy to cause spontaneous combustion and explosion of lithium batteries, which has become a problem for manufacturers. 2. Why is a lithium battery necessary? The limitation of battery selection depends to a large extent on the development and commercial conditions of the battery itself. The world’s first battery volt stack was made of zinc plate and tin plate. After that, zinc and copper batteries, wet batteries, and dry batteries appeared one after another. Because they are not missing and easy to carry, dry batteries will be used for a long time afterwards. It has been widely used and later replaced by the rechargeable nickel-iron battery invented by Edison. In the end, lithium cobalt oxide was used as the positive electrode material, and the lithium battery made of lithium metal as the negative electrode material became the last choice in the market. Compared with other batteries, lithium batteries have obvious advantages. Its service life is very long, more than six years, and the battery is small in size and high in energy density, which can reach 460-600Wh/kg, which is 6 to 7 times that of lead-acid batteries. At present, Tesla announced that the energy density of the 21700 battery system jointly developed with Panasonic has reached 300Wh/kg. At the same time, aluminum batteries have high power tolerance, and lithium iron phosphate batteries used in new energy vehicles can reach 15-30C charge and discharge capacity, which is convenient for high-intensity startup and acceleration of vehicles. Lithium batteries are highly adaptable to high and low temperatures, are environmentally friendly, and basically do not consume water during processing. As for the commercial aspect of batteries, due to multiple constraints such as volume and weight, energy storage and release capacity, storage time, service life, cost, ease of use, and mass production, there are only a few batteries that can be used in large-scale commercial applications. Combining these two reasons, lithium batteries have become the best solution. Although the nature of the lithium battery determines its fate of flammability and explosion, it is not completely impossible to reduce the risk and safety. Whether it is a mobile phone company or a new energy vehicle company, through a reasonable battery management system and thermal management system, the battery can ensure safety, and there will be no explosion or spontaneous combustion. 3. How to solve it? Batteries will release heat during work, and will spontaneously ignite and explode before release. Therefore, it can be managed by the battery thermal management system. The thermal management system equipped with new energy vehicles is a subsystem of the battery management system, which can cool the battery when the temperature is too high, and preheat it when the temperature is low, which is better To give full play to the performance of the battery, Tesla’s unique battery management system is a typical representative. Tesla equipped its processed cars with thousands of lithium cobalt oxide batteries to supply kinetic energy. The 18650 battery it uses can be recharged more than 1,000 times. However, due to the large unit density and capacity of the battery, there is a risk of spontaneous combustion and fire. higher. And Tesla uses its battery management system to monitor various physical parameters of the battery in real time, evaluate the battery usage status, and perform online diagnosis and early warning. At the same time, it can also perform discharge and precharge control, battery balance management and thermal management, etc. . Take its battery thermal management as an example, through liquid cooling, that is, 50% water + 50% ethylene glycol, to control the temperature rise of the battery. 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: What are the advantages of lithium battery UPS?