The development of the automotive industry is the development of the entire upstream and downstream industry chain. With regard to the rise of new energy vehicles, the core position of power batteries has become increasingly prominent. The technical topics of power batteries are also controversial, material types, safety, battery standards, life expectancy, and price costs. As to where the future power battery should go, and the views of relevant business leaders and researchers, the reporter understands the current and future development of power batteries.
Power battery development will go from here
Good power battery, speak with product
Dong Yang, executive vice chairman of China Automotive Industry Association: What is the current short board? What is the short board in the product? It is a power battery. The development of new energy vehicles can not be used to seek mileage in exchange for the weight of the battery, battery costs should be reduced, the transition to no subsidies, do a good job of lightweight vehicles, and continuously improve the power battery level.
The first can not be used to quest for the mileage of the battery in exchange for mileage; the second to reduce the cost of the battery, to transition to no subsidies; the third is not only the battery, motor system is better, and the entire vehicle's lightweight, wind resistance performance must be improved; fourth The most critical thing is to improve the level of power batteries.
The construction of the test center must first have a pilot test base. There is no research or equipment to talk about. This is the process of battery research and development. This is a test center project. Actually, everybody’s test is mainly a statutory test. The analysis of materials is particularly environmental and safety testing, and now our testing capability is seriously inadequate.
Meet different needs, a variety of battery common development
The head of the overall expert group of the electric vehicle major project of the Ministry of Science and Technology, and Ouyang Minggao, the standing committee member of the National Committee of the Chinese People's Political Consultative Conference (CPPCC): Different models use different batteries, for example, passenger cars value the driving range, and use high-energy triple lithium-ion batteries. The goal for the development of batteries by 2020 is 300 watt-hour/kg for single cells and 200 watt-hours/kg for systems, which is the level that ternary lithium-ion batteries can achieve. Passenger cars are more important for safety and can use lithium iron phosphate batteries that have a lower specific energy but higher stability.
For the current concept of fiery graphene batteries, Ouyang Minggao said that the use of graphene in batteries is basically based on articles published in the publication, and none of them are complete batteries for experiments. The application of battery materials is divided into several levels. In the basic research phase of materials, it is necessary to go through several levels from materials to electrodes to monomers and then to systems. Each layer faces different problems, so do not use graphene in the short term. Battery applications hold great promise on electric vehicles.
At present, graphene is mainly added as a conductive reinforcing agent to the positive and negative electrode materials of the battery to improve the conductivity and enhance the charge/discharge rate of the battery. Ouyang Minggao expects that graphene batteries may first be used in consumer batteries, such as mobile phone batteries, button batteries, and so on. However, in the power battery dominated by pure electric cars, the future is still mainly ternary lithium batteries.
"To achieve the goal of integrating an urban passenger car power system with an integrated platform, we must strengthen the deepening of industrial development and improve scientific research and technological capabilities so as to ensure the safety, stability, and growth of new energy vehicle development projects."
China started the research and development of electric vehicles for electric vehicles in China from the “15th Five-Year Plan†special focus on electric vehicles, which was mainly nickel-metal hydride batteries and lithium manganese batteries. "Eleventh Five-Year", mainly lithium iron phosphate batteries. By the "Twelfth Five-Year Plan", China's focus on R&D will shift to three-cell lithium-ion batteries. In 2015, the specific energy of Chinese ternary lithium-ion batteries is expected to reach 180 watt-hours per kilogram. By 2020 it is expected to exceed 200 watt-hours per kilogram, which is twice as high as it is now.
According to foreign trends, China's basic development goal for 2020 is that high-specific energy batteries reach 300 watt-hours per kilogram, life expectancy 1500 times, and cost 8 cents. Ouyang Minggao emphasized that in the process of moving toward high-energy lithium-ion batteries, opportunities and challenges will coexist and safety issues will become more prominent. The higher the energy ratio, the greater the challenge. "China must pay more attention to safety. Among the three issues of safety, durability and dynamics, the most important issue is the issue of security."
The problem of power battery safety is summarized as power battery thermal runaway. When the battery is heated to a certain temperature, it is not controllable, and the temperature rises linearly, exceeding 500 degrees and 1000 degrees, and then a combustion explosion occurs. Temperature triggers side reactions in the battery. These side reactions can exotherm, causing thermal runaway. In addition, electrical triggering can also cause this problem. External short circuits, internal short circuits, and overcharges all result in heat production and then thermal runaway. Another reason is collision. After the vehicle has been squeezed and squeezed, the battery will be short-circuited just like it was needled. Then it will produce heat, and the heat will cause thermal runaway.
Ouyang Minggao suggested that China should study and study the safety design of Tesla batteries. "It should be said that Tesla is using an unsafe battery. It is not safe from the standpoint of the single cell. However, an unsafe battery makes the system safe because Tesla's battery uses 7000. More than 18650 ternary batteries, nickel-cobalt-lithium, single-cell unsafe batteries are safe to combine, this is a patent for Tesla's safety design, and these patents can be carefully analyzed because now Tesla's patents are all public."
Since 2014, the Chinese government has issued a series of preferential policies. China's new energy automobile industry has entered a period of rapid development. The rapid increase in battery investment and the battery industry have achieved growth, but there is still a situation in which demand exceeds supply. Ouyang Minggao pointed out that the development of the battery industry is not a simple investment issue, and the proportion of investment in research and development is even more important. For electric vehicle power systems, whether it is extended-range plug-in hybrid systems, pure electric power systems, or fuel cell power systems, we must comprehensively consider and analyze the core technologies and advantages and disadvantages of each system, and steadily increase the quality and increase. The amount of development. Therefore, the development of China's power battery should maintain a reasonable rate of development.
Power battery industry lacks collaborative innovation mechanism
Lu Shigang, president of the National Automobile Power Battery Research Institute, currently uses three types of power systems for nickel-metal hydride batteries, lithium-ion batteries, and fuel cells in electric vehicles. Nickel-metal hydride batteries are currently very mature and mixed in Prius. Power has been widely used, of course, Prius sales have reached more than 7 million vehicles, and now we are talking about lithium-ion batteries, according to the classification of lithium iron phosphate (LFP), lithium manganese oxide (LMO), lithium nickel cobalt manganese oxide Lithium-nickel-cobalt-aluminate, the latter two we call the ternary system. Therefore, from this table, it can be seen that at present, the lithium ion battery has changed from lithium iron phosphate to three yuan, and the monomer energy can reach 180. It can be seen that this ternary material battery should have some room for development. The limit density can reach 250 or even 260. This is a direction that we should say in the industry.
First of all, look at the development status of our country. The first of our judgments is to basically grasp the key technologies of automotive power batteries. The development of our national power battery is basically synchronized with that of the entire vehicle. NiMH batteries, lithium-manganese oxide lithium-ion batteries, lithium-ion batteries, The research and development and industrialization of lithium iron phosphate batteries was enhanced during the “Eleventh Five-Year Plan†period. The development and industrialization of ternary materials batteries was promoted during the “Twelfth Five-Year Plan†period. It is at this stage.
Technically speaking, our country has developed nickel-metal hydride batteries, lithium-ion fuel cells, and key technical indicators have reached an advanced level of similar foreign products. At present, our lithium batteries can achieve system specific energy of 800-1000 watt-hours, specific power. Can achieve 500-100 watts, cycle life can also be achieved through a thousand times, the service life is probably up to five years, the cost is probably that can be lower than three bucks per watt.
From the point of view of development trends, the world’s first case is that lithium-ion batteries have become the main direction of power batteries. At present, everyone is very clear that the current commercial batteries in Japan, the United States, Europe, and South Korea mainly use fuel cells. The current hybrid is also an application of lithium battery. South Korea, Japan, and China dominate the world in lithium batteries, ranking first in Korea, second in Japan, and third in China.
The Chinese government strongly supports the research and development of the new generation of power batteries. In 2012, Japan implemented the power storage strategy and proposed that the battery market should account for 50% of the world's share in 2020, which is to recapture the world's number one position. According to the technology roadmap released by NEDO in 2013, his technology line is probably based on advanced lithium-ion batteries before 2020. It is practical. The system's specific energy reaches 250 watts per kilogram and costs less than 1.5 yuan. It is called in 2030. Innovative batteries have an energy of 500 watts per kilogram and cost less than eight cents.
According to our country's plan, our country's battery specific energy will reach 300 watt-hours per kilogram in 2020, which is about six years. Therefore, we believe that the country should establish a new generation of specialized battery innovation focused on research and development and investment, breaking the new generation of lithium ions. For batteries and new batteries, the specific energy of the battery system will reach 250Wh/kg in 2020, and the cost will drop to 1.0yuan/Wh; the specific energy of the new system battery will reach more than 400Wh/kg.
Strengthen the construction of innovative engineering capabilities,. The first is to build a new generation of engineering materials for research on new materials and key technologies for power batteries, to connect basic research, engineering development, and product development. The second is to build a design verification capability for power battery products and transform the technical requirements of electric vehicles into power batteries and batteries. System design requirements.
Accelerate the promotion of industrial collaborative innovation, the government takes the lead, industry organizations, joint automobile companies, and battery companies. First, jointly develop a roadmap for the power battery technology, identify milestone goals and tasks, and guide the development of China's power battery industry; we believe this is very important. It should be said that this task is also very urgent and we should unify everyone’s understanding. The second is to jointly develop the general technical specifications of the power battery, specify the design, manufacture, storage, transportation and recycling requirements of the battery product, and promote the accelerated development of the power battery industry in China.
Equipment lagging behind China's battery development
Xu Daquan, executive vice president of Bosch (China) Investment Co., Ltd.: It is not enough energy to talk about battery-plus-motor replacement and current perspective. For example, we are talking about the current price of 200 kWh per kilogram. We simply convert all the heat consumption into consideration. It may be nearly two kilowatt-hours per kilogram, with a tenfold difference in the middle, and the cost is probably two to three per watt hour. The money, in short, is about 40 to 120,000 yuan for a 40-kilowatt vehicle. It still cannot be compared with gasoline engines and diesel engines.
In China, the primary material for lithium batteries, and the entire equipment for the second processing and manufacturing, from this perspective, we are still lagging behind these leading Japanese and Korean companies, so there are many needs in this area. Wherever efforts are made, Bosch, as one of the suppliers, also wants to enter this point.
The specification is a basic threshold, which has little impact on most companies in the field of power batteries. Basically, production capacity and product performance can be achieved. There may be some companies that need to increase some testing equipment to ensure the performance of products, such as XRAY testing equipment, coating Cloth thickness gauge and so on.
For some testing equipment, the country has no mandatory requirements, but there will be a white list. It is worth noting that the requirements of downstream customers in this area began to increase, which will allow domestic battery companies to increase the use of some testing equipment to better achieve battery performance.
The importance of battery management technology
Sun Fengchun, vice president of Beijing Institute of Technology: The core technology of power battery is still to be broken, the importance of battery management system. In addition, it is the application of the battery that we have experience for more than 20 years. The battery has no management. From the earliest 103 batteries in Beijing, we haven't managed to replace the battery for three months. It is now 48 months. So Battery Management I think that the application of batteries is also very important.
220V battery to minus 25 degrees, full after discharge can be put about 40%, charging can only charge about 40%, discharge is better, this is the charging of our small current charging 220 can only charge to 118, discharge Fortunately, low-temperature charging is a relatively big problem. It is very important how to put the battery system inside the battery and control the temperature of the charging problem.
The inconsistency of battery standards is not conducive to development
Qin Xingcai, president of Tianjin Lishen Battery Co., Ltd.: The question of battery standards, what is this standard, is now useful for flexible packaging, various sizes of flexible packaging, useful large squares, but also various sizes, but also cylindrical, various models. Now, the scale of production and the degree of investment are not high. Can not meet the requirements of investment plants, investment is not too large, the model may not be determined, two days after the car factory did not choose this model, and may not be able to produce.
Now our country proposes that a hundred people will be able to propose that the system can be different. We can have a variety of materials, but our models, like the previous, my AA batteries, the No. 1 batteries, the few batteries, I set several sizes and Standards, so recommend to the depot to select, also recommended to the battery factory, you engage in industrialization in accordance with this to prevent the higher the degree of automation now, the future of the car plant does not choose this model, and may be greater losses.
Power batteries should work together with upstream and downstream companies
Hefei Guoxuan Group Co., Ltd. Chairman Li Wei: The market space is unlimited. The International Energy Agency predicts that by 2020, our global automobile sales volume will reach 7.2 million units in the year, our sales will reach RMB 2 trillion, and our batteries will reach RMB 600 billion. Scale, we all know that our battery company started in the second half of last year, the entire market space, sales are very good, we should change the low-cost, low-quality, low-value, low-price vicious circle and low-end manufacturing, we should adapt to the new normal, high-tech The development of high-quality, high-efficiency products has become possible from the fact that our batteries cannot be equipped with world-class companies, the United States, and the world's markets.
Collaboration is very important. We have always worked closely with our upstream and downstream companies, including our equipment manufacturing companies for eight to ten years, making our China's innovative equipment able to produce our batteries. Can install a good battery for our car. We also cooperate with our material companies such as Betrix and our own products, and the batteries we manufacture enable China's electric vehicles to enter the international market.
Guoxuan started earlier in the development process. With the support of the government, it was established in Hefei City in 2009. So we united with our vehicle manufacturer. In 2009, we cooperated with Ankai, China. It is also the world’s first electric-only commercialized electric bus line of 30 vehicles. From January 23, 2010 to the full launch of the market today to January 23, five years of results, we will share this data with everyone, we should say that, use our equipment, our materials, our The technology to produce our automobiles can be operated stably for five years. In China and in the world, it is also more avant-garde. This is the result of our cooperation with auto factories. Of course, Guoxuan not only cooperates with Jianghuai, Ankai, etc. We have a series of cooperation with BAIC, SAIC, Dongfeng, etc. I think that our battery manufacturing companies must only cooperate with our auto companies for a win-win situation. Our auto companies should support our battery companies, continue to innovate, continue to innovate independently, and constantly use our own capabilities and levels to be able to put our The contribution of products and the loading of our cores into the international market are our fundamentals.
The technical route of the power battery should be determined by the market
Tianneng Group Chairman Zhang Tianren: Let the market decide, that is to say let consumers decide, now don't talk about which battery is good, which battery is not good, because China, after all, is a vast land, a large population, there are each A variety of consumer layers.
Now the development of electric vehicles in China, his technical line of batteries, we advocate and advocate continuous innovation, continuous progress in the process, for example, we talk about lead-acid batteries, lead batteries are not like the previous lead batteries, the original The specific energy of lead batteries is less than 20, now it is 35, 40, and the specific energy of the highest super battery reaches about 70-80 watts per kilogram, and its service life is about 350 cycles. The best lead battery now has a 70-percent DOD discharge case, like the United States, reaching more than 4,000 times, surpassing nickel-metal hydride batteries, and is in a sense reaching our lithium-ion battery so one Level. Therefore, I think that lead batteries are particularly suitable in China, especially in low-speed transportation applications.
The problem is that the technology is relatively mature, the price is relatively low, the security is very good, or it can be recycled and reused. His international recycling and recycling, the United States reached 98.5%, we China can now reach about 90%, so any industry , I think it is only possible to recycle and reuse, and then to develop such an industry is sustainable, so my point is that the technical route of the power battery, not limited to a battery, I think the lead battery has a lead battery is very Big advantage.
Lithium-ion batteries, he is certainly a direction of development, we remember when we began to want to do lithium batteries ten years ago, when the lithium battery life, price, safety problems, now it seems that our two years The cost has just been mentioned by experts. Our price/performance ratio has reached two to three bucks, which is two to three times that of lead-acid batteries. This is a significant price drop, and the safety has also been greatly improved. , And fully in line with our future high-speed development of electric vehicles, so this is a problem, this is a point I want to say, that the electric vehicle's power battery technology line should be determined by the market.
LG battery safety performance research and development production
Senior Vice President of LG Chemicals and Director of the Automotive Battery Development Center, Jin Xiuling: LG Chemicals attaches great importance to safety, so our technology is first of all, the raw materials and design of the batteries are all made by ourselves. The SRS separation membrane will be described in detail later, and the most important for the design of the cell is the energy ratio between the cathode material and the anode material and the resistance ratio between the cathode and the anode. As far as electronic protection is concerned, sensing accuracy and protection levels, protection classification, and then safety parameters and algorithms are the most important items.
The SRS Separation Membrane we are talking about is a shorthand for safety-enhancing diaphragms. In the middle is our common polyolefin diaphragm. This is a ceramic nanoparticle, which is what we call the SRS diaphragm. When the temperature of the battery rises, the separator will be melted first. This makes it easy for the cathode and the anode to come into contact with each other to form an internal short circuit. With the ceramic diaphragm, even if it is melted off, because of the ceramic nanoparticles, the cathode and the anode are not directly contacted. At present, all batteries for pure electric vehicles are ceramic diaphragms, which increases safety. What we also want is stronger is the protection of BMS. The more high-capacity batteries, the higher the security requirements for these two. First, the BMS generally measures the voltage, temperature, and current of the cell.
The second generation battery has improved a lot of measurement accuracy for the first generation battery. The second is the BMS protection level. The general protection level is divided into three levels. The first is performance guarantee, the second is to ensure safety but the performance will be affected, and the third is that safety performance may be affected. Taking into account the possibility of BMS damage, some companies have added a BMS, and some companies have added a DR protection integrated circuit. The more high-energy batteries need such double protection.
The next-generation battery requires a reasonable cost and the most basic safety performance. It also has to achieve a charge of 500 kilometers or more, fast charging, and cooling systems. In order to meet such requirements of customers, what our battery needs to do is to have an energy density of 80 to 100 kWh, fully charge in 30 minutes, reduce the resistance of the cell, and have good storage performance. Below is a comparison of LG Chemical's batteries. Judging from the battery cells that our customers require, LG Chemicals nickel iron phosphate has a volume of 400 liters and a weight of 800 kilograms to meet. The recent second-generation battery needs 200 liters in volume and 400 kg in weight to meet such customer needs. However, at present our customers propose that the second-generation battery is also a little big in size and weight, so LG Chemicals is developing a new battery. We hope its standard is 600 watts per liter. Developing a high-energy battery at LG Chemicals uses a high-energy chemical material. What we want to emphasize again is that safety performance is very important, so we are not only improving the safety of the batteries, but also strengthening the overall design of the BMS and battery packs, and ensuring safety.
Three yuan battery triggered three yuan hot
At the China Electric Vehicles Centennial Conference, Zhang Xiangmu, Director of the Department of Equipment of the Ministry of Industry and Information Technology, caused a lot of controversy. He said: "The Ministry of Industry and Information Technology will organize and carry out a risk assessment for lithium-ion batteries. Before the completion of the evaluation, the suspension of three-cell lithium battery passenger cars will be included in the list of recommended models for the promotion and application of new energy vehicles."
Today, the Ministry of Industry and Information Technology has made it clear that due to the consideration of power battery safety issues, the suspension of three yuan lithium battery passenger cars will be included in the list of recommended models for the promotion and application of new energy vehicles. This decision has caused fierce discussions in the new energy vehicle and battery industries, and most of them are fighting for ternary materials. The ternary battery is either good or bad, temporarily unpredictable, and time is the best method of verification.
Jinlong Automobile Group Co., Ltd. Secretary of the Party Committee and Chairman of the Board Lian Xiaoqiang: With regard to the disabling of the Sanyuan Lithium Battery for electric buses, Lian Xiaoqiang said that the stability of Sanyuan Li-ion batteries is not as good as that of Lithium-ion batteries, but the safety of batteries cannot be passed only through batteries. Material to judge. The safety of the battery is determined by the control system including the packaged system and the strictness of the production control. Therefore, more attention must be paid to the balance of the production process.
Wuzhou Long Chairman Zhang Jingxin: Insufficient production capacity and system safety of power batteries have become two major problems that have plagued the new energy automotive industry this year. â€
The first is tight supply and insufficient capacity. The company has a large backlog of orders this year because it can't get batteries and can't deliver smoothly. Second, the low-temperature performance of iron-lithium batteries has not yet been solved. Low-temperature problems could have been solved with supercapacitors, supercapacitors. Low temperature performance is very good, but to get policy subsidies, it is necessary to ensure the cruising range of pure electric buses, so doomed super capacitors can not replace iron and lithium batteries. In the field of electric buses, iron-lithium batteries are still the current mainstream, but the high and low temperatures have not been solved; ternary batteries have good low-temperature performance and higher energy density, but they are still not the main direction.
There is currently a trend toward the use of ternary batteries, but safety issues are involved and it is not easy to achieve large-scale promotion. Wuzhou Long had installed a prototype vehicle with a Boston ternary battery. The test run was not bad, but Wuzhou Dragon will not use a ternary battery in the short term. Now the Sanyuan battery can reach 205wh/kg after being grouped, and LFP only has 100wh/kg. With the maturity of BMS and management testing methods, the conditions for the application of ternary batteries are also becoming mature.
Xu Yanhua, deputy secretary-general of the China Automobile Industry Association, said that the ternary material battery has just started in China and the safety development and verification for electric buses is not enough. The relevant test standards are not perfect and there are potential risks.
However, opponents said that lithium iron phosphate battery is not absolutely safe, there have been previous cases of fire. Song Han, director of micro-power market and strategy, said: Many battery companies do not recognize the government's unified technical line of battery delineation. From the perspective of safety, “Sanyuan Lithium batteries are not necessarily unsafe and lithium iron phosphate batteries are not necessarily safeâ€.
Lithium battery expert Wang Qingsheng, senior researcher at the University of St. Petersburg, Russia: Materials, processes, structures, and systems are indispensable. It is not the battery properties determined by that material. The battery industry is developed, and when the materials have advantages and disadvantages.
It is no exaggeration to be cautious in terms of security. Security is no small matter. Yu Yurong, Chairman of Suzhou Yuliang Yu proposed to adopt the fail-safe measures that are commonly used in the world, that is, in the event of a battery burning or a failure, to ensure the safety of passengers. He believes that as long as the quality of the battery is ensured and safety measures are strengthened, neither the lithium iron phosphate nor the ternary material battery will pose a threat to the personal safety of the passenger. Therefore, there is no need to limit the use of any kind of battery for commercial vehicles.
Hai Yintong New Energy Co., Ltd. CEO Xue Jiayu: If the quality of the power battery produced by China's lithium car manufacturers is not as good as the international manufacturers or the consistency is not good enough, it is impossible for the Chinese electric car manufacturers to open up the domestic product network and lower the quality standards to lower the purchase price. Quality of domestic lithium battery products. Similarly, if China's lithium battery manufacturers still manufacture low-energy-density lithium iron phosphate batteries as before, the result must be pushed to the low-end market by ternary lithium products of other countries. "So, the consistency and energy density of power lithium battery products are the key to the success of lithium motor vehicles in China in the future. We must strongly encourage Chinese power lithium battery manufacturers to use ternary materials."
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