The rhythm of ternary lithium batteries replaced by solid-state batteries is getting faster.
Recently, the Institute of Materials Technology and Engineering of the Chinese Academy of Sciences announced that the nano-lead special 'all solid-state battery' project led by it has passed the acceptance test. This technological advancement will further promote the scale application of domestic all-solid lithium batteries.
As soon as this news came out, it immediately caused a huge response in the battery industry.
Industry insiders told the first electric network: 'With the current technical route of ternary lithium battery, the goal of 350Wh/kg for power battery energy density monomer is basically impossible to achieve in five years. Moreover, even if it is realized, safety Sex can't be guaranteed. Therefore, whether the commercialization of solid-state batteries can break through, has a significant impact on the future of automotive electrification.
As the core of electric vehicles, the breakthrough in the battery field will undoubtedly have a major impact on the development of batteries and even the automotive field. So, can solid-state batteries immediately replace ternary lithium batteries? How far is it from marketization?
Natural defects of ternary lithium batteries: energy density and stability are contradictory
'A single company had 60 electric vehicle combustion explosions last year.' At the China-Japan-Korea Lithium Forum, the director of the New Energy Materials and Technology Laboratory of Peking University revealed that Professor Lu.
His professor believes that there are many defects in the ternary lithium battery, and the safety issue is very worrying. 'In terms of chemical structure and battery structure, the ternary material is very prone to heat. If the heat cannot be conducted in time, There is a risk of explosion in the battery. However, at this stage, there is no perfect solution to the safety and reliability of the battery.
In addition to safety issues, in terms of increasing the endurance angle of electric vehicles, the single-energy density of ternary lithium batteries is nearing the limit, and it is difficult to be broken. Battery pack supplier Zhengli Weilai executive vice president Zhou Nan told the first electric: 'Now, whether it is industry policy or market demand, new energy vehicles have high requirements on the energy density of power batteries. Under the existing technology system, to increase the energy density, only nickel materials or CA can be added, but High nickel has poor thermal stability. Therefore, once the energy density of a conventional battery is increased, it means a decrease in stability. The internal thermal reaction of the battery will be very intense, and safety becomes a big problem.
For this reason, Xiao Chengwei, an expert of the National Expert Group of the National '863' Plan for Energy Conservation and New Energy Vehicles, has publicly stated that the ternary lithium-ion battery has seen the 'ceiling' of energy density, high nickel material, carbon. The lithium battery cell of silicon negative electrode should have a maximum energy density of about 300Wh/kg, and the positive and negative should not exceed 20Wh/kg.
According to the national power battery technology roadmap, the single-energy density target for lithium-ion batteries in 2020 is 350Wh/kg. From the current point of view, this goal has not been achieved.
In order to ensure the high energy density and safety of the power battery, the development of solid-state battery development has brought light and light to the industry.
Domestic and foreign companies compete for layout, solid-state battery trends
Solid-state batteries, as the name suggests, are batteries that use solid electrodes and solid electrolytes. Because solid-state battery electrodes and electrolytes are made of solid materials, their solid electrolytes are non-flammable, non-corrosive, non-volatile, leak-free, and also overcome lithium. The dendritic phenomenon, even if heated to a very high temperature, will not catch fire, so it is safer. The car with an all-solid-state lithium battery will have a much lower probability of spontaneous combustion. It can be said that it is the next generation of new energy vehicle power battery. Ideal object.
At present, more and more domestic and foreign companies and research institutions are focusing on all-solid-state lithium batteries, and many automakers have revealed plans to build electric vehicles based on solid-state batteries. For example, Volkswagen has announced plans to develop a 1000km solid-state battery. Toyota Motor is expected to complete the research and development of solid-state batteries in 2022 and plans to achieve mass production in 2030; the Ministry of Economy and Economy of Japan announced that it will contribute 1.6 billion yen in 2017, in conjunction with Toyota, Honda, Nissan, Panasonic, GS Yuasa, Toray, Asahi Kasei, Mitsui Chemicals, Mitsubishi Chemical and other domestic top industrial chain forces, jointly develop solid-state batteries, hope to achieve 800 kilometers of endurance in 2030.
Academician Ouyang Minggao, the chief expert of the national key technology of new energy vehicles, also pointed out that many domestic research institutes and enterprises are in the field of solid-state batteries. The Ningbo Institute of Materials Science and Technology of the Chinese Academy of Sciences is cooperating with Yanfeng Lithium Industry to promote its industrialization. Mass production of solid state batteries.
As the 'heart' of new energy vehicles, the power battery will undoubtedly determine the future of new energy vehicles. Industry insiders generally believe that the future development path of power batteries is electrolytes from liquid, semi-solid, solid-liquid mixed to solid state, and will eventually achieve all solid state. The process. This prompted startups, universities and Tesla and other well-known giants to invest in and research on battery technology.
Toyota's timetable is relatively reliable, and solid-state battery production may have to wait until 2030.
However, solid-state batteries want to be further developed, and multiple problems still need to be solved.
Zhou Nan told the first electric: 'Solid electrolyte is the key to the development of solid-state batteries. Solid-state batteries do not have liquid infiltration, and they do not need a diaphragm. They only use solid electrolyte as a separator and are placed in the positive and negative pole pieces. The material of metallic materials becomes especially critical. '
Electrolyte materials are the core of all-solid-state lithium battery technology. At present, the research of solid electrolytes mainly focuses on three types of materials: polymers, oxides and sulfides. Polymers have good high temperature performance, and there are commercial applications; oxide cycle Good performance, suitable for flexible film structure; sulfide conductivity is the highest, is the main direction in the future.
However, there are still several specific challenges that need to be overcome:
First, the conductivity of the interface, the conductivity of the solid state battery should be maintained at an appropriate level, not too high, nor too low, such materials are very difficult to develop.
Second, there is no composite material that can be considered both high-rate and fast-charge. The solid electrolyte materials used now can only accommodate one of the characteristics.
An industry insider who did not want to be named expressed the same view. He believes: 'The solid electrolyte has high electrical resistance. There are still some problems to be solved in terms of power density. It is necessary to start with solid electrolytes and positive and negative materials. There are no small challenges in terms of conductivity, battery rate, battery preparation efficiency, and cost control. Once these problems can be effectively solved, a new battery revolution will surely start in the future.
Since there are many difficulties, how long does it take for solid-state batteries to be fully utilized in new energy vehicles?
Ouyang Minggao said that it is expected that all solid-state lithium batteries will break through between 2025 and 2030. In May of this year, Shinzuo Abe, general manager of Toyota Powertrain Division, revealed: 'Toyota expects to manufacture solid-state batteries after 2020 However, if you want to achieve mass production of solid-state batteries, you still need to wait until 2030. '
Zhou Nan, who has been deeply involved in the battery industry for more than ten years, said to the first electric: "From the experience of the past, the Toyota plan and the actual situation are basically the same. Maybe in the past few years, they can The introduction of solid-state batteries, but the specific capacity is how, the cost can not adapt to the market, but also to play a big question mark.
