Application of fast battery charging in different technical routes -Lithium - Ion Battery Equipment
The speed of charging is closely related to the overall technical and design requirements of the power battery, charging pile, electric vehicle, power grid, etc., among which the battery is the biggest factor. We will specifically discuss the application trend of different types of power batteries in the direction of fast charging technology. Almost all kinds of positive materials can be used to make fast charging batteries, but their applicability and advantages and disadvantages are different.(Lithium - Ion Battery Equipment)
1. The ternary fast charging battery is more suitable for electric passenger vehicles
Ternary battery is paid more attention because of its high energy density. The material itself has excellent conductivity, but its reactivity is too high, so it poses a great challenge to the safety of fast charging.
The representative enterprises of the ternary battery fast charging system include Ningde Times, Bike, etc. Ningde Times has developed the "Superconducting Electronic Network" and "Fast Ion Ring" technologies, which can achieve SOC charging from 5% to 85% within 15 minutes, energy density of 190Wh/kg, and cycle life of more than 2500 times. The main application field is passenger cars, and it is expected to have the capacity of mass production in 2018.
The latest 3.0 high-energy core launched by BYK in May this year has an energy density of nearly 250Wh/kg, and can achieve an ultra long endurance mileage of 500km by introducing silicon negative electrode materials, high nickel positive electrode materials, and specially developed electrolyte. The charging strategy is designed to effectively shorten the charging time and improve the charging efficiency. In extreme emergency mode, it can drive 60 km after 10 minutes of charging.
According to the usage habits of fuel vehicles, to fully charge within 10-20 minutes, the charging rate should be at least 3-6C. At present, most of the pure electric passenger vehicles on the market are charged with 80% of the power in half an hour to one hour, which has improved a lot compared with the previous two or three hours of charging time, and is expected to be further compressed to 20 minutes in the future.
2. Lithium iron phosphate fast charging is available to passengers
Lithium iron phosphate does not have inherent advantages in the field of fast charging. From the material point of view, the intrinsic conductivity of lithium iron phosphate material is relatively low, which is only one percent of the ternary material. The conductivity of lithium iron phosphate material needs to be optimized to meet the needs of fast charging. However, the material cost of lithium iron phosphate is relatively low. Combined with mature technical background and stable product performance, it has a relatively broad application prospect. The representative enterprises are Ningde Times, Watma, etc.
Limited by the extreme limit of theoretical energy density, lithium iron phosphate has little room to play in energy density in the future. However, for passenger cars, logistics vehicles, special vehicles and other commercial vehicles, lithium iron phosphate system is now used, which is not necessary for the improvement of energy density, while fast charging is increasingly showing its importance.
3. Lithium manganate battery is applicable to plug-in hybrid bus
Lithium manganate battery has the characteristics of power performance, discharge rate performance, good low-temperature performance and high voltage frequency. In addition, under the situation of soaring ternary upstream raw materials, the cost advantage of lithium manganate is gradually highlighted. However, the energy density and high temperature performance still need to be improved. In recent years, the proportion of lithium manganate fast charging batteries in the field of plug-in hybrid passenger cars has increased significantly, and the representative enterprises are UNITA Guli, Yipeng New Energy and Micromacro Power.
However, the cycle performance of lithium manganate battery at high temperature is poor, and the high temperature performance of lithium manganate battery can be improved by positive electrode doping, but the modified lithium manganate material is no longer the "original lithium manganate". "Multi composite materials" are commonly used in the industry. The positive electrode uses ternary materials and lithium manganate mixed system, and the negative electrode uses porous composite carbon to further improve the performance of fast charging, but the safety still needs to be focused on and constantly improved.