How do you have powerful lithium battery safety?

　　Author ：Iflowpower – Portable Power Station Supplier

This year, the safety problem of electric cars is a bit more. According to the data of the State Market Supervision Administration, in 2018, there were at least 40 fire accidents involved in new energy vehicles. Since the April this year, the electric vehicle is attached to the electric car, and the safety of lithium battery is a sensitive topic.

Another topic that cannot be avoided. Recently, my country's Dynamic Lithium Battery Innovation Alliance Under Secretary-General, Wang Zi, deputy secretary-general of my country Electric Automobile Charging Infrastructure Charging Alliance, Wang Zi, in the first my country International Electric Automotive Safety Technology Innovation Conference, multi-dimensional analysis of electric vehicle safety issues. He believes that the power lithium battery has no distinction in the material, it is difficult to further break more than the energy to a certain level.

At the same time, the negative impact in security is getting bigger and larger. The problem that the balance between control energy density and safety and long life is not overlining without having to master the lithium-ion battery. my country's Power Lithium Battery Innovation Alliance, Deputy Secretary-General Prince of my country Electric Automobile Charging Infrastructure Charging Alliance.

Prince Winter said, "We do not admit that the battery pack is a component containing high-energy substances, which is of dangerous nature, and with the increase in battery comparison, the risk of accidents will increase. "In a large number of technical routes of lithium-ion batteries, lithium iron phosphate and three yuan of downtime. Lithium iron phosphate has high safety, long life, but the energy density is not as high as three yuan, but it can be made up of battery capacity, the low temperature performance is poor, and it is important to low temperature performance on small capacity battery, and the material consistency is also poor.

The energy density of the ternary battery is high, the consistency is good, the low temperature performance is good, but the safety is slightly poor, and the cycle life is far less than the lithium iron phosphate ion battery. "Currently, in my country's lithium iron phosphate ion battery has the most mature industrial chain, we have more core technologies in the relevant category, and the three-yuan battery is represented by Japanese and South Korea, relatively mature. "Prince Dong believes that this kind of technology route is more than a kind of VS Japanese and South Korea.

If the performance of the power lithium battery itself is evaluated, he lists 10 dimensions: 1. Safety of battery packs, 2. The energy density of the battery pack (rather), 3.

The cycle life of the battery pack, 4. Cost of the battery pack, 5. Charging magnification, 6.

Battery monomer consistency, 7. Low temperature performance, 8. Group utilization, 9.

Easy to recycle reuse, 10. Positive and negative material can be recovered and reuse. As a technology route that can lead the trend, there is no distinctive shortcoming in any of the above aspects, and the balance of all aspects is a feasible route, not a single performance indicator.

For example, energy density. Therefore, from the above 10 aspects, in this pair, the three yuan and phosphite lithium is tragic, the painful competition, there is a winner, there is a flat hand, after these 10 games, the prince's winter referee, give one Simple final conclusion: In case of safety, energy density requirements are not very high, preferred lithium iron phosphate ion batteries. Where is the ceiling of a power lithium battery? In the face of prince, there is a clear understanding of improving the energy density of the power lithium battery: the performance of the power of electric vehicles that can industrial automobiles is improved, not only the performance of the positive and negative material, but also in many respects There is a big breakth, it is possible to improve the true meaning of the dynamic lithium battery.

Then, from the meaning of the industrial dynamic lithium battery, the goal proposed by the state is that it can run 400km by electric vehicle charging at 2020, and the monomer battery is reached: 300Wh / kg (350), 600WH / L (700) 0.6 yuan / WH, battery system reached: 220WH / kg (260), 300WH / L (380), 1.0 yuan / WH, cycle life is 1500 times (80% DOD).

Wang Zi Winter said that from the indicator data, if you want to achieve these indicators, it is more difficult. At present, domestic dynamic lithium battery company product profile is: Lithium iron phosphate, the economy of energy-type phosphate dynamic lithium battery is roughly between 140-180WH / kg. In terms of three raw materials, the large-scale processed three-dimensional active lithium battery energy density is substantially between 180-260Wh / kg.

Introduction to the technical perspective, if the battery pack is 260WH / kg, according to the energy consumption calculation of 10kWh / kg / 100km, the 40KWh battery pack battery core weight cannot exceed 99.5kg, the total weight of the battery pack cannot be More than 153kg, the soft packaging battery is more than 402Wh / kg, which is difficult to know. From this, it can be launched, and the energy that reaches 350WH / kg (if possible), it is necessary to make a large capacity (80ah or more) aluminum alloy hard shell power lithium battery, which saves the weight of the modularization.

The total weight of the 40KWH battery should be controlled within 114.3kg, which can only account for 74.7% of the battery pack, and the remaining aluminum alloy box (25kg), thermal management system (2kg), connector and fixing member (11.

7kg), etc., the total weight cannot exceed 38.7kg, the weight of the station battery pack is 25.

3%, the total weight of the battery pack can not exceed 153kg, the battery pack is more than 262Wh / kg. "Why do you think that a high energy density thinks of soft packaging battery? From the perspective of the vehicle engineering, the energy density of the power lithium battery system, not the energy density of the monomer battery. From the monomer battery to the module, then to the system integration, the intermediate link is more, the connector between the battery, the connection cable, the box, the fixing frame, the support frame, the heat conductive structure, etc.

, which will have added a lot of new Weight ", Prince Dong proposed, optimization in system energy density, reliability and safety. .