Evaluation and research on the safety performance of power lithium batteries -Lithium - Ion Battery Equipment
From April 24th to 26th, the Ninth China International Energy Storage Conference hosted by the Energy Storage Application Branch of the China Chemical and Physical Power Industry Association was held at the Intercontinental Hotel in Hangzhou, Zhejiang Province. On the afternoon of April 25th, in the special session of "Energy Storage Battery and Technology Application (Part 2)", Xie Xianyu, deputy chief engineer of the Vehicle and Parts Testing Center of Shanghai Motor Vehicle Testing and Certification Technology Research Center Co., Ltd., shared the theme report " Research on Safety Performance Evaluation of Power Batteries", the following is the transcript of the speech:(Lithium - Ion Battery Equipment)
Xie Xianyu: Ladies and gentlemen, good afternoon! I come from the Shanghai Motor Vehicle Testing Center. As a third-party testing organization in the country, I have accumulated rich experience in carrying out relevant testing from the whole vehicle to the component level. Combined with the related work of Shanghai's new energy application, I will take this opportunity to share with you Everyone share.
My report today includes the following aspects: first, some background information on the current safety testing of power batteries; second, the introduction of relevant standards for power batteries at home and abroad; third, the evaluation of the safety of power batteries; fourth, a summary .
As we all know, whether it is the electric vehicle fire incident last year or this year, the first thing everyone thinks of when an electric vehicle catches fire is the power battery, at least the suspect is relatively large. In fact, everyone should take a look. When an electric vehicle catches fire, the battery may be a part of it. In fact, there are other reasons, such as the charging system itself, or the interconnection of the entire system, or some related question. Specific to the power battery, there are some cases of extreme abuse, and there may also be some system problems, such as some problems that occur during the charging process, there may be problems not only with the power battery itself, but also with the car and the charging system communication issues, etc.
The discussion goes back to electric vehicles, which may have various problems during use, such as inability to drive, significant decrease in mileage, lack of power, etc., which may stem from power battery problems, such as capacity fading may be due to its effective lithium usage Reduced, the battery itself has insulation failure problems, liquid leakage problems, etc. These problems are related to its past and present life, in its material selection process, manufacturing process, and even in its actual application process.
How we evaluate the safety of a battery should be analyzed from the micro and macro dimensions. The micro is analyzed from the material level, and the macro is analyzed from the system level, including the structure of the entire electrical safety, functional safety, chemical safety and other related considerations. . In the evaluation and safety evaluation of power batteries, it should be a closed-loop system, that is, from materials to final products, whether it is batteries, modules or systems, and finally these performances are reflected in the application process, especially the key points Safety performance should be a closed-loop system. When we analyze it, we should analyze it in combination with its past and present lives. As we all know, electric vehicles are required to be connected to the national monitoring platform, power batteries should have a traceability system, and batteries are traceable and managed from relevant information such as material selection, manufacturing, testing, use, and decommissioning.
The United States, the European Union, etc. have conducted research on safety-related standards for electric vehicles and key components earlier. In recent years, the relevant standard systems for electric vehicles and power batteries in my country have gradually improved. Internationally well-known research institutions for these power batteries, such as SAE, ISO, UL, etc., have formulated a system of standards, which cover cells, modules, and systems, and test items include electrical performance, safety, and reliability.
Next, some typical standards are introduced, such as UN38.3, because the power battery is transported as a dangerous product, and a UN38.3 test report must be issued before transportation, involving the test content from T1 to T9.
Now draw more, including the American FreedomCarSand2005-3123 standard, the test content includes: mechanical abuse, heat abuse, electrical abuse test, etc. Thermal abuse is also the focus of our country, specifically for thermal abuse, including thermal diffusion, thermal runaway expansion and other related requirements, and also recommends some corresponding testing methods and testing procedures. This process should be said to be very instructive, and the number of test samples and the order of tests should be reasonably arranged.
SAEJ2464 has made a detailed introduction from mechanical, thermal abuse, and electrical abuse.
Let me focus on the UL2580 standard in the United States. In addition to the mechanical environment experiment we mentioned earlier, it has more characteristics in electrical testing. It mentions temperature rise experiments, including unbalanced charging, and even cooling system failure. Experiments, because these experiments may actually encounter these problems that we will face in the actual application process. Let’s take a simple example, such as the heat balance failure system. As you may know, in recent years, under the premise of higher and higher energy density requirements, some models have canceled the thermal management system due to cost and weight considerations. The impact of the new car is not too great, but after two or five years, the battery life and safety performance will be a big question mark.
EU ECER100, power battery has been a mandatory requirement since 2016, and there are 10 test items. The requirements of these standards are similar to those of our domestic related standards.
Back in China, before 2015, the standards related to power batteries should be relatively lacking. If you are familiar with this industry, the earliest battery announcement experiment in 2015 was based on the industry standard QC/T743 of the automotive industry, which has a certain impact on the early stage. However, with the release of our entire series of standards, including GB/T31467, 31484, 31485, 31486, and the recently released traceable Relevant standards such as the system to the retreat and recycling system, as well as the recently mentioned national power battery safety standard, have played a good role in the front end of our products after these standards have been introduced one after another. Specifically 31485, monomer and module-related safety requirements experiments. 31467.3, battery system mandatory test requirements, a total of 16 items.
The safety technical requirements of electric buses, power batteries have thermal runaway and thermal runaway expansion requirements, mainly due to the hidden danger of mass casualties and injuries in passenger cars. At present, relatively safe lithium iron phosphate batteries are mainly used, and ternary batteries cannot be used at present.
Let me focus on the new GB power vehicle battery standard. Because it is a GB mandatory standard, the current WTO notification is expected to be released in June or July this year. After the release, there will be a transition period of about one year in the middle, and it may be implemented after July 2020. . This standard covers GB/T31485 and GB/T31467.3, and at the same time combines battery thermal runaway and thermal runaway expansion related content in electric bus safety, and the standard also defines related test procedures.
Comparing domestic power battery safety standards, at the battery cell and module levels, in terms of the entire test items and requirements, our standards are relatively stricter. You can take a look at the system level. Our original 31467.3 standard largely borrowed from the ISO12405 standard.
Here is a comparison of different standards for the acupuncture test. For example, the extrusion plate form of the power battery we are talking about, including the new national standard, the ECER100 standard, the UL2580 standard, and the SAEJ2464 standard, regardless of the extrusion direction, extrusion degree, and retention The time, test objects, SOC status before the experiment, and the requirements of the experiment are all different. Compared with international standards, the requirements of relevant standards in my country are relatively strict.
Generally speaking, there are still many test standards for power batteries at home and abroad, and the test methods and acceptance standards are also different. The current power battery safety-related standards in our country are relatively comprehensive after several years of development. It basically covers some major international test items, including battery development trends and dynamic updates, such as thermal management-related test items, which will be further standardized and considered in the later stage. At the same time, the safety testing of power batteries in my country should be further strengthened in terms of testing resources, testing equipment, and research objects.
Finally, I will briefly introduce some power battery test case analysis we are doing. This is the requirement of electric vehicles. First of all, these requirements on the vehicle must be met, and the corresponding test requirements for the power battery system, including its performance, safety, reliability, and even battery interface requirements. Among these requirements, the focus is on the requirements for safety performance. At present, while conducting relevant announcement experiments for customers or OEMs, in fact, many enterprises have test requirements that are far greater than the standard requirements. When enterprises conduct experiments, they not only require It is only a Yes/No relationship, but what requirements can be achieved, and there will be a lot of research and development experiments. This is a typical acupuncture experiment. Although there was no fire or explosion, which met the standard requirements, it will analyze the voltage changes and temperature conditions of these adjacent cells.
We also conduct acupuncture, overcharge and other abuse test studies on different ternary battery cells, different types of batteries, such as flexible packaging, square batteries, and different material systems.
At the same time, as you can see, the thermal diffusion analysis of the lithium iron phosphate battery system triggers its thermal runaway through acupuncture. We can see the temperature of the surrounding cells, including the voltage. Study the analysis of related thermal performance through overcharging and heating methods, and look at other related thermal performance characteristics after some batteries fail.
The management of the surrounding environment after heat dissipation includes the internal and external conditions of the battery pack after local failure. Including three comprehensive experiments, combined with vibration, environmental changes, charging and discharging working conditions, including mechanical shock experiments, and extreme extrusion experiments of battery packs. When doing the extrusion test, the extrusion direction is different, in fact, the results may be different. For example, the position of the high-voltage interface and the wiring harness have an impact on the test results.
For the fire test, the standard requires 2 minutes. In fact, many manufacturers may let you burn for 10 minutes or half an hour when they do the test. There are also tests such as simulated crash test, water immersion test, drop, reliability, and protection function verification. Generally speaking, these verifications mainly control the front-end security performance of new products. It is necessary to further strengthen safety supervision during and after the event.
At present, the safety of the entire power battery should be further improved. There are many related standards at home and abroad. These standards are mainly used for the entry or mandatory requirements of new products, but the supervision and related standards during and after the event need to be further studied and improved. The standard system can be used as a reference in the field of energy storage batteries.
Generally speaking, battery technology, whether it is lithium battery or sodium battery, these new battery technologies are constantly emerging, whether it is used in power batteries or energy storage batteries, it should be said that the methods and standards of the entire test and evaluation are also constantly changing. Newer ones require joint research and development by the industry.
Xie Xianyu: Ladies and gentlemen, good afternoon! I come from the Shanghai Motor Vehicle Testing Center. As a third-party testing organization in the country, I have accumulated rich experience in carrying out relevant testing from the whole vehicle to the component level. Combined with the related work of Shanghai's new energy application, I will take this opportunity to share with you Everyone share.
My report today includes the following aspects: first, some background information on the current safety testing of power batteries; second, the introduction of relevant standards for power batteries at home and abroad; third, the evaluation of the safety of power batteries; fourth, a summary .
As we all know, whether it is the electric vehicle fire incident last year or this year, the first thing everyone thinks of when an electric vehicle catches fire is the power battery, at least the suspect is relatively large. In fact, everyone should take a look. When an electric vehicle catches fire, the battery may be a part of it. In fact, there are other reasons, such as the charging system itself, or the interconnection of the entire system, or some related question. Specific to the power battery, there are some cases of extreme abuse, and there may also be some system problems, such as some problems that occur during the charging process, there may be problems not only with the power battery itself, but also with the car and the charging system communication issues, etc.
The discussion goes back to electric vehicles, which may have various problems during use, such as inability to drive, significant decrease in mileage, lack of power, etc., which may stem from power battery problems, such as capacity fading may be due to its effective lithium usage Reduced, the battery itself has insulation failure problems, liquid leakage problems, etc. These problems are related to its past and present life, in its material selection process, manufacturing process, and even in its actual application process.
How we evaluate the safety of a battery should be analyzed from the micro and macro dimensions. The micro is analyzed from the material level, and the macro is analyzed from the system level, including the structure of the entire electrical safety, functional safety, chemical safety and other related considerations. . In the evaluation and safety evaluation of power batteries, it should be a closed-loop system, that is, from materials to final products, whether it is batteries, modules or systems, and finally these performances are reflected in the application process, especially the key points Safety performance should be a closed-loop system. When we analyze it, we should analyze it in combination with its past and present lives. As we all know, electric vehicles are required to be connected to the national monitoring platform, power batteries should have a traceability system, and batteries are traceable and managed from relevant information such as material selection, manufacturing, testing, use, and decommissioning.
The United States, the European Union, etc. have conducted research on safety-related standards for electric vehicles and key components earlier. In recent years, the relevant standard systems for electric vehicles and power batteries in my country have gradually improved. Internationally well-known research institutions for these power batteries, such as SAE, ISO, UL, etc., have formulated a system of standards, which cover cells, modules, and systems, and test items include electrical performance, safety, and reliability.
Next, some typical standards are introduced, such as UN38.3, because the power battery is transported as a dangerous product, and a UN38.3 test report must be issued before transportation, involving the test content from T1 to T9.
Now draw more, including the American FreedomCarSand2005-3123 standard, the test content includes: mechanical abuse, heat abuse, electrical abuse test, etc. Thermal abuse is also the focus of our country, specifically for thermal abuse, including thermal diffusion, thermal runaway expansion and other related requirements, and also recommends some corresponding testing methods and testing procedures. This process should be said to be very instructive, and the number of test samples and the order of tests should be reasonably arranged.
SAEJ2464 has made a detailed introduction from mechanical, thermal abuse, and electrical abuse.
Let me focus on the UL2580 standard in the United States. In addition to the mechanical environment experiment we mentioned earlier, it has more characteristics in electrical testing. It mentions temperature rise experiments, including unbalanced charging, and even cooling system failure. Experiments, because these experiments may actually encounter these problems that we will face in the actual application process. Let’s take a simple example, such as the heat balance failure system. As you may know, in recent years, under the premise of higher and higher energy density requirements, some models have canceled the thermal management system due to cost and weight considerations. The impact of the new car is not too great, but after two or five years, the battery life and safety performance will be a big question mark.
EU ECER100, power battery has been a mandatory requirement since 2016, and there are 10 test items. The requirements of these standards are similar to those of our domestic related standards.
Back in China, before 2015, the standards related to power batteries should be relatively lacking. If you are familiar with this industry, the earliest battery announcement experiment in 2015 was based on the industry standard QC/T743 of the automotive industry, which has a certain impact on the early stage. However, with the release of our entire series of standards, including GB/T31467, 31484, 31485, 31486, and the recently released traceable Relevant standards such as the system to the retreat and recycling system, as well as the recently mentioned national power battery safety standard, have played a good role in the front end of our products after these standards have been introduced one after another. Specifically 31485, monomer and module-related safety requirements experiments. 31467.3, battery system mandatory test requirements, a total of 16 items.
The safety technical requirements of electric buses, power batteries have thermal runaway and thermal runaway expansion requirements, mainly due to the hidden danger of mass casualties and injuries in passenger cars. At present, relatively safe lithium iron phosphate batteries are mainly used, and ternary batteries cannot be used at present.
Let me focus on the new GB power vehicle battery standard. Because it is a GB mandatory standard, the current WTO notification is expected to be released in June or July this year. After the release, there will be a transition period of about one year in the middle, and it may be implemented after July 2020. . This standard covers GB/T31485 and GB/T31467.3, and at the same time combines battery thermal runaway and thermal runaway expansion related content in electric bus safety, and the standard also defines related test procedures.
Comparing domestic power battery safety standards, at the battery cell and module levels, in terms of the entire test items and requirements, our standards are relatively stricter. You can take a look at the system level. Our original 31467.3 standard largely borrowed from the ISO12405 standard.
Here is a comparison of different standards for the acupuncture test. For example, the extrusion plate form of the power battery we are talking about, including the new national standard, the ECER100 standard, the UL2580 standard, and the SAEJ2464 standard, regardless of the extrusion direction, extrusion degree, and retention The time, test objects, SOC status before the experiment, and the requirements of the experiment are all different. Compared with international standards, the requirements of relevant standards in my country are relatively strict.
Generally speaking, there are still many test standards for power batteries at home and abroad, and the test methods and acceptance standards are also different. The current power battery safety-related standards in our country are relatively comprehensive after several years of development. It basically covers some major international test items, including battery development trends and dynamic updates, such as thermal management-related test items, which will be further standardized and considered in the later stage. At the same time, the safety testing of power batteries in my country should be further strengthened in terms of testing resources, testing equipment, and research objects.
Finally, I will briefly introduce some power battery test case analysis we are doing. This is the requirement of electric vehicles. First of all, these requirements on the vehicle must be met, and the corresponding test requirements for the power battery system, including its performance, safety, reliability, and even battery interface requirements. Among these requirements, the focus is on the requirements for safety performance. At present, while conducting relevant announcement experiments for customers or OEMs, in fact, many enterprises have test requirements that are far greater than the standard requirements. When enterprises conduct experiments, they not only require It is only a Yes/No relationship, but what requirements can be achieved, and there will be a lot of research and development experiments. This is a typical acupuncture experiment. Although there was no fire or explosion, which met the standard requirements, it will analyze the voltage changes and temperature conditions of these adjacent cells.
We also conduct acupuncture, overcharge and other abuse test studies on different ternary battery cells, different types of batteries, such as flexible packaging, square batteries, and different material systems.
At the same time, as you can see, the thermal diffusion analysis of the lithium iron phosphate battery system triggers its thermal runaway through acupuncture. We can see the temperature of the surrounding cells, including the voltage. Study the analysis of related thermal performance through overcharging and heating methods, and look at other related thermal performance characteristics after some batteries fail.
The management of the surrounding environment after heat dissipation includes the internal and external conditions of the battery pack after local failure. Including three comprehensive experiments, combined with vibration, environmental changes, charging and discharging working conditions, including mechanical shock experiments, and extreme extrusion experiments of battery packs. When doing the extrusion test, the extrusion direction is different, in fact, the results may be different. For example, the position of the high-voltage interface and the wiring harness have an impact on the test results.
For the fire test, the standard requires 2 minutes. In fact, many manufacturers may let you burn for 10 minutes or half an hour when they do the test. There are also tests such as simulated crash test, water immersion test, drop, reliability, and protection function verification. Generally speaking, these verifications mainly control the front-end security performance of new products. It is necessary to further strengthen safety supervision during and after the event.
At present, the safety of the entire power battery should be further improved. There are many related standards at home and abroad. These standards are mainly used for the entry or mandatory requirements of new products, but the supervision and related standards during and after the event need to be further studied and improved. The standard system can be used as a reference in the field of energy storage batteries.
Generally speaking, battery technology, whether it is lithium battery or sodium battery, these new battery technologies are constantly emerging, whether it is used in power batteries or energy storage batteries, it should be said that the methods and standards of the entire test and evaluation are also constantly changing. Newer ones require joint research and development by the industry.
