Lithium batteries have attracted much attention due to their high specific energy, low self-discharge, long cycle life, no memory effect and green environmental protection. At present, lithium-ion batteries mainly include the following materials: lithium cobalt oxide, lithium manganate, lithium iron phosphate, and the less common iron manganese phosphate.
(1)Lithium cobalt oxide power battery
Lithium cobalt oxide is the first generation of commercial lithium-ion battery and has many advantages: high specific energy, stable performance, high volume specific energy, and stable high and low temperature discharge capacity. The disadvantages are poor safety, high price and environmental pollution. The current commercialized small power lithium-ion battery material is mainly lithium cobalt oxide.
(2)Lithium manganate power battery
Lithium manganate has a higher voltage platform, higher safety performance, and low price. The disadvantages are low specific capacity, poor cycle performance, and poor high-temperature cycle performance. Almost all known lithium-powered vehicles announced by global mainstream car manufacturers use lithium manganate electric vehicle batteries. Japan's Toyota, Nissan, Honda, and Mitsubishi are developing lithium manganate as power batteries for electric vehicles. Ford of the United States, Renault of France and other automobile manufacturers have been testing lithium manganate power batteries for a long time. Domestic Peking University New Energy Materials and Technology Laboratory and CITIC Guoan Mengli Company have been committed to the development of new lithium-ion secondary batteries for power for several years. Recently, they have been engaged in the synthesis of key battery material lithium manganate and power battery technology research respectively. Breakthrough progress has been made.
(3)Lithium iron phosphate power battery
Lithium iron phosphate has gradually become a research hotspot for power batteries in recent years. It has the advantages of high safety, good cycle performance, green environmental protection and low price. The disadvantages are: low voltage platform, low tap density, low rate current, and poor low-temperature discharge performance. It has become a bottleneck restricting the commercialization of lithium iron phosphate. Research in recent years has made great breakthroughs in low-temperature performance and rate current. The lithium iron phosphate produced by Japan's Mitsui Company can be charged and discharged at a maximum rate of 20C, and the capacity can maintain more than 90% after 500 charges and discharges at a rate of 3C.