How Lithium Battery Performance and Safety Work Together
The continuous occurrence of electric vehicle safety accidents has drawn much attention to the safety of power batteries. How to meet the ever-increasing energy density of power batteries and the increasing mileage requirements of vehicles while improving their safety and prolonging their service life is a topic of concern to the global automotive industry. On October 13, at the 11th International Electric Vehicle New Lithium Battery Conference (ABAA11) held in Huzhou, Zhejiang, automotive industry engineers and government department managers from all over the world discussed the development of automotive lithium batteries to explore Innovative development of lithium batteries for vehicles.
Energy density and safety must be balanced
"Currently, power batteries are facing great safety challenges in use, which requires us to strengthen battery safety research and technology improvement." As Ouyang Minggao, academician of the Chinese Academy of Sciences and professor of Tsinghua University, said, in the application of electric vehicles The exposed power battery safety issues have sounded the alarm for the industry, requiring the industry to improve its technical level and safety performance. Ye Shengji, deputy secretary-general of the China Association of Automobile Manufacturers, pointed out that lithium-ion batteries are one of the core components of new energy vehicles. Driving mileage, cycle life and other aspects of demand. "In our country, there are clear requirements for the performance of power batteries in all aspects, and specific numerical indicators are proposed for energy density and cost. Energy density and safety are the goals that must be considered in the development of power batteries. A topic facing the global power battery practitioners." Ye Shengji said.
"Lithium batteries will overflow lithium decomposition and heat during operation. Once the battery is overheated, safety accidents such as explosion or combustion may occur. However, the pursuit of high energy density for automotive batteries to increase driving range is a common goal pursued by the industry. In the process of the goal, how to balance energy density and safety? This requires us to continuously improve technology and do innovative research and development.” Sun Shigang, academician of the Chinese Academy of Sciences and professor of Xiamen University, said in an interview with a reporter from China Automotive News. In fact, the auto industry of various countries is trying to improve the technical level to ensure the safety of electric vehicles. Ouyang Minggao introduced that they are strengthening the management of power battery heat through research on diaphragm technology, and on this basis improving the safety performance of power batteries; Atsushi Ohma, the relevant person in charge of Nissan Group, also introduced that Nissan uses binders to improve battery performance. Stability; Andress Hintennach, the relevant person in charge of the Mercedes-Benz Group, said that they are conducting research on the carbon layer made of olivine, with the purpose of improving battery performance and achieving structural stability. However, the chemical structure of this material is relatively complex, and new difficulties may arise in practical applications.Also read:12v 500ah lithium ion battery
Under the premise of ensuring safety performance, improving the energy density, cycle life and reducing costs of batteries is the unremitting research direction of the global power battery industry, and it is also the focus of discussion at the ABAA meeting. In order to achieve the above goals, the automobile industries of various countries continue to innovate research methods, material processes, and management ideas, hoping to improve the performance of automotive lithium batteries through technological innovation and better meet market demand.
Fast charging is the unanimous goal of the industry
It is a prerequisite for the market-oriented development of electric vehicles to realize fast charging of electric vehicles like fast refueling of fuel vehicles, and it is also the unanimous goal of car companies and relevant management departments. At the scene, almost all car companies mentioned the topic of fast charging. International car companies, including BMW, GM, Nissan, Mercedes-Benz, and Volkswagen, all proposed development plans for fast charging without exception, charging more than 80% in 10 to 15 minutes It has also become a common requirement for the industry from the management departments of various countries. The relevant person in charge of Ford said that he hopes to achieve the charging goal of no less than 300 miles (482.8 kilometers) in 15 minutes through a high voltage of more than 800 volts.
DaveHowell, a staff member of the US Department of Energy, said that it is a common requirement of consumers to control the charging time within 10-15 minutes. In the research and development project led by the US Department of Energy, increasing the charging speed without affecting the service life of the battery itself is an important research direction. "Tesla's super charging pile can achieve a charging speed of 200 miles (321.8 kilometers) in 20 minutes. We hope to be faster, and we can achieve such a charging mileage within 15 minutes or even 15 minutes. This is what we are striving for. direction.” Similarly, the fast-charging goal proposed by the U.S. Department of Energy is also the level that government management departments such as China, Japan, and Germany hope to achieve.
In fact, fast charging will damage the life of lithium batteries, and the current technical level and material structure cannot solve the contradiction between fast charging and battery life. Wu Feng, an academician of the Chinese Academy of Engineering and a professor of Beijing Institute of Technology, pointed out that the current lithium battery performance and battery characteristics formed by the material structure determine that fast charging will inevitably damage the battery life. This is its chemical characteristic and is an objective existence. The industry needs to continue to carry out scientific research and innovation, and develop new materials and structures to meet the needs of fast charging of lithium batteries. "We need to increase the power density of charging piles and ensure the safety during high-current fast charging.
Ouyang Minggao also pointed out that electric vehicles have good development prospects in my country, and it is estimated that the number of electric vehicles in the near future will exceed 8 million to 10 million. However, in the process of increasing the number of electric vehicles, the convenience of product use must also be solved. How to solve this problem? He believes that in the future, electric vehicles will enter the stage of charging network development combined with the Internet to improve the convenience of charging.Also read:10kwh lithium battery
DaveHowell further emphasized that while improving battery performance, battery costs must also be continuously reduced. "In the past 20 years, the cost of batteries has been greatly reduced. In the future, the cost of batteries still needs to be further reduced. It is hoped that the cost of positive and negative electrode materials can be reduced by 5% or even more." In this regard, researchers from various countries are actively promoting materials. Improvements or substitutions, such as trying to use titanium alloys, aluminum-nickel alloys and other materials. "The cost of cobalt is very high. We can consider increasing the application of nickel materials in lithium batteries, replacing cobalt or reducing the amount of cobalt, so as to reduce costs while ensuring the performance of power batteries." Sun Shigang said.
Strengthen exchanges and cooperation to promote the development of automotive lithium battery industry
"my country's power battery industry is facing a situation of overall overcapacity and insufficient high-quality production capacity. Diversified development has become a trend and will face a new round of reshuffle." Wu Feng emphasized how to start with basic research and systematically It is an urgent task for the power battery industry to solve the problems of high specific energy, safety, long life, and low cost of power lithium batteries. Specifically, in terms of technology, in the high specific energy and high nickel lithium ion battery system, should a liquid flame retardant electrolyte or a solid electrolyte be used to solve its safety problem? In the multi-electronic system, should we take the technical route of lithium sulfur and break through the technical bottleneck of increasing the volume specific energy, or use lithium-rich cathode materials to break through the technical bottleneck of long cycle life? Can the material system be cobalt-free to significantly reduce battery costs? How to establish a safety threshold boundary for a power battery system to achieve quantitative description and control of a safe state? Will the preparation process of power lithium batteries produce subversive changes? Is there a green recycling and regeneration technology approach for waste power lithium batteries? These issues all depend on our extensive and in-depth academic and technical exchanges.
Zhou Guohui, vice chairman of the Zhejiang Provincial Political Consultative Conference, also said that power batteries are the core components of new energy vehicles and the heart of electric vehicles. The rapid development of the new energy vehicle industry is inseparable from major breakthroughs in power battery technology. This requires international counterparts to communicate and cooperate on the premise of respecting and protecting intellectual property rights, especially in the deep integration and development of the Internet and globalization. Unilateralism and trade protectionism will not work. "Green development and innovative development are the economic and industrial development directions that countries in the world are generally pursuing. The new energy vehicle industry and technology perfectly integrate the two. This time, we will jointly discuss the cutting-edge technology and market applications of power batteries. The breakthrough development of power batteries will help." Zhou Guohui said. He also introduced that relying on the local power battery industry foundation, Huzhou actively promotes the permanent settlement of the ABAA conference in Huzhou. With the help of the establishment of an international exchange platform and the continuous deepening of international exchanges, it has promoted the development of the local and even the entire Zhejiang new energy vehicle industry.
Ye Shengji believes that to achieve the development goal of power batteries, we need the joint support and help of domestic and foreign counterparts to overcome various difficulties encountered in the process of technological progress; we must build a communication platform for coordinated development, strengthen international cooperation and coordination and personnel training, and develop the industry. Guide and standardize the role to accelerate industrial development. Wu Feng also pointed out that the ABAA meeting has built a platform for exchanges and cooperation. He hopes that through the collision of ideas among scholars from various countries, the vitality of lithium battery research and the development potential of related industries can be further stimulated, new problems and new gaps can be continuously identified, and new issues can be proposed. Ideas, new methods, and research on new countermeasures.