What is the bottleneck of new energy vehicle battery technology -- background
The Minister of industry and information technology said that from the perspective of China's industrial development, with the continuous improvement of the penetration and ownership of new energy vehicles, the industrial development has entered a new stage, but some problems of unbalanced and insufficient development have gradually become prominent: first, charging infrastructure is still a short board of development; Second, the policy system still needs to be improved; Third, further breakthroughs are needed in core technology; Fourth, the post market circulation service system needs to be improved.
What is the bottleneck of new energy vehicle battery technology -- Introduction
Among the constituent materials of lithium battery, there are iron phosphate, manganese, graphite, titanate and other metal and non-metallic materials. However, the mutual conversion of electric energy and chemical energy can be realized only by the insertion and removal of the element "lithium ion" in the positive and negative electrodes, and finally the charging and discharging process can be completed. However, the technological progress of lithium battery is slow. Although the energy density and other performances of lithium-ion battery have been greatly improved after development, according to the current position and size of vehicle fuel tank, and the battery weight meets the requirements of vehicle bearing capacity and axle load distribution, the specific energy of power battery shall reach 500-700wh / kg. The energy density of current lithium-ion batteries is far lower than this value. Therefore, at present, improving the energy density of power battery is a bottleneck restricting the development of lithium-ion battery, or it is difficult to meet the rapidly growing demand for electronic products and electric vehicles.
What is the bottleneck of new energy vehicle battery technology -- corresponding research
In recent years, researchers have made great efforts to improve the energy density (power volume capacity ratio), value, safety, environmental impact and trial life of lithium batteries, and are designing new types of batteries. However, paserini said that now the traditional lithium battery technology is close to the bottleneck, and the space for further optimization is limited. In order to break through the bottleneck problem of low energy density, domestic and foreign scholars have mainly done the following research.
In terms of materials, silicon-based and tin based alloys are used as cathode materials for lithium-ion batteries. Through the improvement of this material, the theoretical capacity of lithium-ion battery can be as high as 4200wh / kg and 990wh / kg respectively, which can fully meet the energy requirements of pure electric vehicle power battery. However, silicon-based lithium-ion battery has huge material volume expansion effect due to charge and discharge process, relatively small diffusion coefficient of lithium in silicon film and significant deterioration of electrochemical performance; Tin based alloy negative electrode battery needs to solve the problems of high irreversible capacity and poor charge discharge cycle performance for the first time. At present, it has not been industrialized in the field of pure electric vehicle power battery.
On the other hand, it mainly makes breakthroughs in preparation technology and group technology. Considering the preparation technology of battery, nano technology is used to improve the performance of battery and develop new nano materials. Considering the group technology, the modular structure of the power battery system can be reasonably designed to reduce the performance attenuation caused by the battery pack composed of battery cells and reduce the impact of the consistency of battery cells in the battery pack; And through the energy management of the battery system on the real vehicle, the further rational distribution and utilization of energy can be realized. At present, it mainly focuses on energy management, charge discharge balance, SOC estimation and so on. In the research of battery pack energy management, for the energy distribution of hybrid electric vehicle, domestic and foreign scholars have done a lot of research on the battery pack energy management and distribution strategy, and summarized a series of energy management and control strategies, such as power following control strategy, on-off control strategy, fixed factor power distribution control strategy, fuzzy control strategy and so on.
Based on the above analysis, the current pure electric vehicle power battery mainly adopts lithium-ion battery. The main technical bottleneck of improving performance lies in further improving the performance level of single battery of pure electric vehicle and improving the management of power battery system of pure electric vehicle.
There is no doubt that the biggest bottleneck of electric vehicles lies in its battery technology. Among them, the endurance and power performance of electric vehicles are the focus of many problems. The power battery system is the key technical problem that restricts the endurance and power performance. Here, I hope the state will formulate policies and improve on this issue as soon as possible. I believe that the future is bound to be the world of new energy! I hope you can enjoy all the content about the bottleneck of new energy vehicle battery technology shared by Xiaobian.
