Lithium-ion battery is a 20th century development of a new type high energy batteries. The battery's anode is lithium, positive MnO2,SOCL2, (CFx) n, and so on. 70 and into the practical.
A conventional lead-acid batteries, nickel-cadmium batteries and nickel-metal hydride battery technology is mature, but as used in automobile batteries, there is a big problem. At present, more and more car manufacturers choose to use lithium-ion batteries battery of new energy vehicles.
Because lithium-ion batteries have the following advantages: high voltage (a nickel-cadmium battery MH-NI battery 3 times); energy (up to 165WH/kg, is the nickel-metal hydride batteries 3 times); small; weight; long cycle life; low self discharge rate; no memory effect; no pollution.
Many well-known auto manufacturers to develop power lithium battery cars, such as the United States Ford, Chrysler, Japan, Toyota, Mitsubishi, Nissan, Korea Hyundai, France Courreges, Ventury, etc. Domestic car maker BYD, Geely, Chery, lifan, zhongxing bus companies also have their own hybrid and pure electric vehicles powered by lithium batteries.
Currently the bottleneck of power lithium-ion battery development is: car battery, safety performance and management systems. Safety performance of lithium ion battery with high energy density, high operating temperatures, poor working conditions and other reasons, and people-oriented security concept, so users have very high demands on the battery safety. Car power battery of management system aspects, due to car power battery of work voltage is 12V or 24V, and single power lithium ion battery of work voltage is 3.7V, so must by multiple battery series and improve voltage, but due to battery to do completely uniform of charging and discharging, so led to series of multiple battery within of single battery will appeared charging and discharging not balance of status, battery will appeared charging insufficient and had discharge phenomenon, and this status will led to battery performance of sharply deterioration, Eventually lead to the entire set of batteries does not work, or even scrapped, greatly affected the battery's service life and reliability.