Lithium battery fast charge in 5 minutes, is it true or false -Lithium - Ion Battery Equipment
At present, most new energy vehicles use lithium batteries, but in actual operation, due to the consistency and safety of lithium batteries, fire incidents of new energy vehicles often occur.
Focusing on technical issues related to lithium batteries, the reporter interviewed He Xiangming, director of the Lithium Ion Battery Laboratory of the Institute of Nuclear Research of Tsinghua University.
Strengthen battery technology and manufacturing level
Reporter: What do you think of the ubiquitous battery consistency problem?
He Xiangming: Mobile phone batteries are used in a single block, but now whether large-scale energy storage or electric vehicles, many batteries need to be connected together. Taking Tesla as an example, thousands of 18650 batteries are connected in series and parallel, which will bring consistency problems, and the actual distribution of current and voltage will be uneven. This will bring two major hazards. One is that the life of the system is greatly reduced;
Reporter: How to ensure the consistency of the battery and prevent problems?
He Xiangming: Everyone's common practice is to screen batteries by a series of parameters such as capacity and voltage. However, the screening process is currently relatively complicated, and the effects are limited. There are also many problems, some of which are caused by measurement errors.(Lithium - Ion Battery Equipment)
At present, the measurement error of the equipment is mostly about 1%. In fact, to meet the battery consistency requirements, the error should be less than 1%. From the manufacturing point of view, the fully automated manufacturing engineering has reduced human factors due to the fixed equipment accuracy and measurement parameters, and has greatly improved in improving consistency.
We are also thinking about other methods to solve the consistency problem, so we propose the idea of using series charging and discharging for consistency screening. Specifically, the consistency of all batteries produced from the factory is first screened, then connected in series, and then charged and discharged, so as to avoid equipment errors.
Reporter: New energy vehicle battery fire incidents are often reported in the newspapers, further highlighting the safety issues of lithium batteries. How to ensure battery safety?
He Xiangming: Battery safety accidents are probabilistic events. Current testing standards cannot completely eliminate battery safety concerns. Lithium batteries are flammable materials with high energy density and have positive and negative electrodes. The heat generated during use will bring about thermal runaway problems. At present, the technical research on the battery body technology is strengthened, and the safety of the battery can be guaranteed in about 5-10 years.
The safety of the battery is closely related to the manufacturing level. For example, if the dust in the air falls on the separator, the human eye cannot see it, but this has a great impact on the performance of the battery. The safety of the battery is closely related to the management level and manufacturing level of the battery factory. To improve the safety and reliability of batteries, it is necessary to gradually improve in all aspects, and to run through all aspects of production management.
10-15 minutes fast charge is more realistic
Reporter: Japan and South Korea are ahead of China in lithium battery technology. Benefiting from the outbreak of domestic new energy vehicles, China is also catching up in lithium battery technology, and the gap is gradually narrowing.
He Xiangming: In the field of lithium batteries, in terms of innovation capability, the United States ranks first; in terms of quality level, Japan ranks first; in terms of manufacturing level, South Korea ranks first. However, China's comprehensive capabilities are the strongest, and it is leading in terms of comprehensive competitiveness and cost-effectiveness of lithium batteries. Therefore, China, Japan, South Korea and the United States are indispensable to the lithium battery industry.
Reporter: There are many reports on the fast charging technology of electric vehicles. Is it feasible to charge in 5 minutes?
He Xiangming: Lithium-ion fast charging is promising, but the online hype that it can be fully charged in 5 minutes is a false proposition. We think 10-15 minutes is a more realistic goal. For example, a car with 50 kWh of electricity needs a 50-kilowatt charging pile to charge it in 1 hour; a full charge in 6 minutes requires a 500-kilowatt charging pile, and a 500-kilowatt charging pile. If the voltage is 220 volts, the current is more than 2,000 amperes , this is impossible, and it will not be used in the cell, which involves the increase of the cell infrastructure. In addition, fast charging has great hidden dangers to the life and safety of the battery.
Focusing on technical issues related to lithium batteries, the reporter interviewed He Xiangming, director of the Lithium Ion Battery Laboratory of the Institute of Nuclear Research of Tsinghua University.
Strengthen battery technology and manufacturing level
Reporter: What do you think of the ubiquitous battery consistency problem?
He Xiangming: Mobile phone batteries are used in a single block, but now whether large-scale energy storage or electric vehicles, many batteries need to be connected together. Taking Tesla as an example, thousands of 18650 batteries are connected in series and parallel, which will bring consistency problems, and the actual distribution of current and voltage will be uneven. This will bring two major hazards. One is that the life of the system is greatly reduced;
Reporter: How to ensure the consistency of the battery and prevent problems?
He Xiangming: Everyone's common practice is to screen batteries by a series of parameters such as capacity and voltage. However, the screening process is currently relatively complicated, and the effects are limited. There are also many problems, some of which are caused by measurement errors.(Lithium - Ion Battery Equipment)
At present, the measurement error of the equipment is mostly about 1%. In fact, to meet the battery consistency requirements, the error should be less than 1%. From the manufacturing point of view, the fully automated manufacturing engineering has reduced human factors due to the fixed equipment accuracy and measurement parameters, and has greatly improved in improving consistency.
We are also thinking about other methods to solve the consistency problem, so we propose the idea of using series charging and discharging for consistency screening. Specifically, the consistency of all batteries produced from the factory is first screened, then connected in series, and then charged and discharged, so as to avoid equipment errors.
Reporter: New energy vehicle battery fire incidents are often reported in the newspapers, further highlighting the safety issues of lithium batteries. How to ensure battery safety?
He Xiangming: Battery safety accidents are probabilistic events. Current testing standards cannot completely eliminate battery safety concerns. Lithium batteries are flammable materials with high energy density and have positive and negative electrodes. The heat generated during use will bring about thermal runaway problems. At present, the technical research on the battery body technology is strengthened, and the safety of the battery can be guaranteed in about 5-10 years.
The safety of the battery is closely related to the manufacturing level. For example, if the dust in the air falls on the separator, the human eye cannot see it, but this has a great impact on the performance of the battery. The safety of the battery is closely related to the management level and manufacturing level of the battery factory. To improve the safety and reliability of batteries, it is necessary to gradually improve in all aspects, and to run through all aspects of production management.
10-15 minutes fast charge is more realistic
Reporter: Japan and South Korea are ahead of China in lithium battery technology. Benefiting from the outbreak of domestic new energy vehicles, China is also catching up in lithium battery technology, and the gap is gradually narrowing.
He Xiangming: In the field of lithium batteries, in terms of innovation capability, the United States ranks first; in terms of quality level, Japan ranks first; in terms of manufacturing level, South Korea ranks first. However, China's comprehensive capabilities are the strongest, and it is leading in terms of comprehensive competitiveness and cost-effectiveness of lithium batteries. Therefore, China, Japan, South Korea and the United States are indispensable to the lithium battery industry.
Reporter: There are many reports on the fast charging technology of electric vehicles. Is it feasible to charge in 5 minutes?
He Xiangming: Lithium-ion fast charging is promising, but the online hype that it can be fully charged in 5 minutes is a false proposition. We think 10-15 minutes is a more realistic goal. For example, a car with 50 kWh of electricity needs a 50-kilowatt charging pile to charge it in 1 hour; a full charge in 6 minutes requires a 500-kilowatt charging pile, and a 500-kilowatt charging pile. If the voltage is 220 volts, the current is more than 2,000 amperes , this is impossible, and it will not be used in the cell, which involves the increase of the cell infrastructure. In addition, fast charging has great hidden dangers to the life and safety of the battery.
