自動車用三元系リチウム電池の開発 -リチウムイオン電池 -イオン電池装置
2022年12月19日
In recent years, China's new energy vehicle industry has forged ahead under the dual advantages of policy and market, and the power battery, as its core component, has also received increasing market attention. As we all know, the core technology of new energy vehicles is "three electrics", namely battery, electric control and motor. As one of the three core components of electric vehicles, battery bears the heavy responsibility of electric vehicle range, and lithium iron phosphate and ternary lithium battery are the mainstream choice of power battery in China.
However, with the progress of R&D technology, ternary lithium battery has a greater potential. Among the eight batches of 296 new energy passenger vehicles announced by the Ministry of Industry and Information Technology in 2017, the largest number of them are lithium ternary, 221 of which are lithium iron phosphate, and only 33 of which are lithium iron phosphate.
Since the beginning of last year, BYD, which has been using lithium iron phosphate batteries, has consistently launched Song EV300, Qin 80, Tang 100 and other matching ternary lithium battery models; In October this year, BYD officially announced that in addition to continuing to use lithium iron phosphate batteries in the public transport sector, all PHEV passenger cars of the company will use ternary lithium batteries in the future; Next year, E5, E6, Qin EV and other pure electric vehicles will also switch to ternary lithium batteries.(Lithium - Ion Battery Equipment)
So, which is better, lithium iron phosphate or ternary lithium battery? In fact, consumers are concerned about nothing more than: which battery has longer range, longer life and is safer. Here we will analyze these problems one by one.
Comparison of energy density (endurance mileage)
Compared with the energy density of lithium iron phosphate battery, the energy density of ternary lithium battery is large and the voltage is higher, so the battery capacity of battery pack with the same weight is larger and the car can run farther. In addition, higher energy density can release more car body space, which is a plus for family users.
At present, a large number of domestic online ternary lithium battery production lines are also closely related to the subsidy policy. According to the prevailing subsidy adjustment scheme for new energy passenger vehicles, in 2018, the energy density of the battery system must reach 140Wh/kg to enjoy 1.1 times of the subsidy, while the subsidy adjustment coefficient for low energy density (105-120Wh/kg) will drop to 0.5, further widening the gap between high-end subsidies and low-end subsidies, and the car enterprises will undoubtedly pursue the former.
The single energy density of lithium iron phosphate battery is usually between 90 and 120Wh/kg, while the single energy density of ternary lithium battery can reach about 200Wh/kg. As the global leader in lithium batteries for vehicles, Ningde Times plans to develop ternary lithium batteries with an energy density of 300-350Wh/kg by 2020, which will make a qualitative leap in the endurance mileage. On the contrary, the research and development of lithium iron phosphate battery has entered a bottleneck in energy density, which has directly led to the abandonment of lithium iron phosphate battery by some automobile enterprises.
Charging efficiency comparison
Lithium terpolymer has obvious advantages over lithium iron phosphate in terms of charging efficiency. When the ternary lithium battery and lithium iron phosphate battery are charged below 10C, there is no significant difference in the constant current ratio. When the rate of charge is above 10C, the constant current ratio of lithium iron phosphate battery decreases rapidly, and the charging efficiency decreases rapidly. For new energy vehicles, a more efficient charging time can significantly improve the driving experience. After all, it is quite helpless to wait for the car to be full before going on the road.
Service life comparison
In terms of service life, lithium iron phosphate has an advantage over lithium ternary in terms of recycling rate, but for ordinary families, the rated cycle life of both is far beyond the actual use. In addition, the low temperature performance degradation of lithium iron phosphate battery is a major defect. The research shows that if a battery with a capacity of 3500mAh works in the environment of - 10 ℃, its power will decline sharply to 500mAh after less than 100 charge discharge cycles. As the main market of pure electric vehicles, the temperature in Beijing is often around minus 16 ℃ in winter, which will cause great trouble for car owners.
However, with the progress of R&D technology, ternary lithium battery has a greater potential. Among the eight batches of 296 new energy passenger vehicles announced by the Ministry of Industry and Information Technology in 2017, the largest number of them are lithium ternary, 221 of which are lithium iron phosphate, and only 33 of which are lithium iron phosphate.
Since the beginning of last year, BYD, which has been using lithium iron phosphate batteries, has consistently launched Song EV300, Qin 80, Tang 100 and other matching ternary lithium battery models; In October this year, BYD officially announced that in addition to continuing to use lithium iron phosphate batteries in the public transport sector, all PHEV passenger cars of the company will use ternary lithium batteries in the future; Next year, E5, E6, Qin EV and other pure electric vehicles will also switch to ternary lithium batteries.(Lithium - Ion Battery Equipment)
So, which is better, lithium iron phosphate or ternary lithium battery? In fact, consumers are concerned about nothing more than: which battery has longer range, longer life and is safer. Here we will analyze these problems one by one.
Comparison of energy density (endurance mileage)
Compared with the energy density of lithium iron phosphate battery, the energy density of ternary lithium battery is large and the voltage is higher, so the battery capacity of battery pack with the same weight is larger and the car can run farther. In addition, higher energy density can release more car body space, which is a plus for family users.
At present, a large number of domestic online ternary lithium battery production lines are also closely related to the subsidy policy. According to the prevailing subsidy adjustment scheme for new energy passenger vehicles, in 2018, the energy density of the battery system must reach 140Wh/kg to enjoy 1.1 times of the subsidy, while the subsidy adjustment coefficient for low energy density (105-120Wh/kg) will drop to 0.5, further widening the gap between high-end subsidies and low-end subsidies, and the car enterprises will undoubtedly pursue the former.
The single energy density of lithium iron phosphate battery is usually between 90 and 120Wh/kg, while the single energy density of ternary lithium battery can reach about 200Wh/kg. As the global leader in lithium batteries for vehicles, Ningde Times plans to develop ternary lithium batteries with an energy density of 300-350Wh/kg by 2020, which will make a qualitative leap in the endurance mileage. On the contrary, the research and development of lithium iron phosphate battery has entered a bottleneck in energy density, which has directly led to the abandonment of lithium iron phosphate battery by some automobile enterprises.
Charging efficiency comparison
Lithium terpolymer has obvious advantages over lithium iron phosphate in terms of charging efficiency. When the ternary lithium battery and lithium iron phosphate battery are charged below 10C, there is no significant difference in the constant current ratio. When the rate of charge is above 10C, the constant current ratio of lithium iron phosphate battery decreases rapidly, and the charging efficiency decreases rapidly. For new energy vehicles, a more efficient charging time can significantly improve the driving experience. After all, it is quite helpless to wait for the car to be full before going on the road.
Service life comparison
In terms of service life, lithium iron phosphate has an advantage over lithium ternary in terms of recycling rate, but for ordinary families, the rated cycle life of both is far beyond the actual use. In addition, the low temperature performance degradation of lithium iron phosphate battery is a major defect. The research shows that if a battery with a capacity of 3500mAh works in the environment of - 10 ℃, its power will decline sharply to 500mAh after less than 100 charge discharge cycles. As the main market of pure electric vehicles, the temperature in Beijing is often around minus 16 ℃ in winter, which will cause great trouble for car owners.