Since 2009, China has begun to subsidize new energy vehicles in order to promote the development of new energy vehicles. As the core component of new energy vehicles, power batteries have always been an important area for new energy vehicles. Among the power batteries, the most eye-catching is the lithium-ion battery.
Lithium-ion batteries have a high energy density, and their capacity is 1.5 to 2 times that of nickel-hydrogen batteries of the same weight, and the self-discharge rate is low. In addition, lithium-ion batteries have almost no "memory effect" and do not contain toxic substances. These advantages of lithium-ion batteries have made them widely used in the field of new energy vehicles.
Today's widely used cylindrical lithium-ion batteries have 18,650 batteries and 21,700 batteries.
The 18650 battery originally referred to the nickel-hydrogen battery and the lithium-ion battery. Since the nickel-hydrogen battery is now less used, it is now referred to as a lithium-ion battery. 18650 is the originator of lithium-ion battery - a standard lithium-ion battery model that Sony SONY Corporation set in order to save costs. Among them, 18 means diameter of 18mm, 65 means length of 65mm, and 0 means cylindrical battery. The common 18650 battery has a ternary lithium ion battery and a lithium iron phosphate battery.
21700 battery
The battery 21700 is a model of a cylindrical battery, specifically: 21 - the outer diameter of the cylindrical battery is 21 mm; 700 - the height of the cylindrical battery is 70.0 mm.
This is a new model developed to meet the requirements of electric vehicles for longer mileage and to improve the effective utilization of vehicle battery space. The same material, 21700 compared to the common 18650 cylindrical lithium battery, the capacity can be more than 35%.
21700 batteries can not be quickly marketized to achieve industrial production, battery companies' research and development technology, manufacturing process is a key, the needs of downstream application terminals and the impact of the introduction of relevant national policies can not be ignored. Its development path requires more than the efforts of battery companies. How to develop the 18650 battery and 21700 battery in the future, and wait and see.
This is a new model developed to meet the requirements of electric vehicles for longer mileage and to improve the effective utilization of vehicle battery space. The same material, 21700 compared to the common 18650 cylindrical lithium battery, the capacity can be more than 35%.
