The Chinese Academy of Sciences Research Institute says solid-state lithium batteries will develop into core technologies

On January 24th, the 2nd China Electric Vehicle 100 People Forum was held in Beijing Diaoyutai State Guesthouse. The theme of this forum is “Building Competition, Innovation and Sustainable Industrial Ecology”. Nearly 100 guests from government institutions, industry scholars, and technology, Internet, automobile, transportation and other fields attended the conference.

The following is a lecture by Li Wei, a researcher at the Institute of Physics of the Chinese Academy of Sciences:

My topic today is "Solid State lithium battery ". In my report, I may be able to answer some questions from Teacher Dong Yang.

What everyone is concerned about is what the core technology of pure electric vehicles in the long run, and how to achieve a revolutionary breakthrough. We also read the technical route of hybrid battery in "Made in China 2025". Basically, this roadmap is consistent with this. In the long run, considering the technical route from China, the United States, and Japan, the next generation will first it is a third-generation lithium-ion battery, followed by metal lithium electronics.

The significance of improving the energy density of the battery is very clear, I am very embarrassed, I use the level of 14 kWh. It can be seen from this that if the energy density is 300Wh/kg, the charge is 470 kilometers, which basically solves the problem of consumer mileage anxiety. At present, the power battery level of mass production also reaches 180Wh/kg.

Our Chinese Academy of Sciences launched a strategic pilot on November 15, 2013. We hope to take a step forward in the introduction of power battery technology and do some basic work. Recently, I worked with the Ningbo Institute of Materials and the physics team and other teams to make a battery. It is a nano-silicon carbon to achieve 24Ah monomer. From this volume energy density, we can see that these two ratios are present. There are still gaps in mature products. Now we want to know where the limits of lithium-ion batteries are. I believe that this year's efforts can also raise this data a bit. It is not yet ideal.

In the long run, metal lithium shows its advantages in this respect because volume expansion is difficult to solve in addition to energy. Metal lithium is now mainly faced with a problem that lithium dendrites are easily generated during charge and discharge. It is possible to consider a positive electrode that does not contain lithium, which is a good opportunity from the overall cost reduction. Now the metal lithium is mainly composed of a metal lithium negative electrode, which can charge and discharge lithium ion positive electrode, lithium sulfur and lithium space. Lithium-air batteries are now open systems, and now with open systems, if the liquid electrode is evaporated, it cannot be fully used. From these considerations, solid-state technology should be adopted to achieve this problem in the long run, so Chen proposed that we should lay out solid lithium batteries in advance. Last year, the first solid-state lithium battery conference was held at the Institute of Physics. Several companies have demonstrated the benefits of solid-state batteries, which are still intact in the event of a fire accident. Inorganic materials are better as electrolytes and may be a fundamental solution for lithium-ion solid-state batteries.

Scientifically speaking, there are many aspects to be studied. The hard part is on the interface, including the design of the cathode material for lithium-ion batteries. The key to accelerating the development of solid-state batteries is to make materials. Therefore, in order to speed up the research and development of this material, Mr. Chen put forward the idea of borrowing from American materials to speed up this speed and strive to realize the industrialization of solid-state batteries. Our country has accumulated a lot of time in solid-state battery research and has accumulated some.

I am here to introduce the work of several young people. Cui Guanglei from Qingdao Research Institute made a 240Wh solid-state battery, which is a 80Ah monomer that works at 60°C and has a certain degree of circulation. Xiaoxiong Xu of Ningbo Institute of Materials is a wetting agent with inorganic ceramics and interface. We currently have no way to do all the solid state. Now it is solid lithium ion, the following is all solid state currently 80Ah can reach 240Wh / kg. The main benefits we can see are that after using a solid electrolyte, it is still possible to cycle at 90 ° C, which is clearly a safety improvement. In terms of energy density, the highest is lithium sulphur and lithium, which are likely to exceed 500Wh/kg in mass density. Considering the stability of use, the ultimate consideration is that lithium-ion battery solid state is the ultimate choice and requires a long way to go.

I will introduce the progress of the Academy of Sciences. The four teams worked together to make lithium-ion batteries, and 70Ah of monomers have been made. It is tested to 616Wh/kg at 50 °C. The safety test passed all the third-party safety tests in the previous few times. The problem now is that the number of cycles is still very low. The number of cycles of this large-density, high-capacity lithium-sulfur battery is 20 times— between 30 times. The next step is to solve the problem of lithium metal. The circulation needs to be improved, and it should meet the cycle requirement of about 500-1000 times. In terms of lithium-air batteries, the Chinese Academy of Sciences has also introduced the actual monomer of lithium air. At present, the monomer can achieve 526Wh/kg, and a 51Ah lithium air battery module has been researched, which is about 360Wh/kg. In recent years, the progress of the pilots has mainly been on these battery aspects, which involve the contribution of a large number of materials, including nano-positive materials, anode materials, interface treatments, and high-voltage electrolytes and ceramic diaphragms. And a comprehensive application of solid electrolyte coated separators. In addition, like the high-level battery diagnosis mentioned by Teacher Dong, we have established a second global interconnection platform. In addition, Mr. Huang has also launched advanced power battery manufacturing equipment in Guangdong, which is probably such a progress.

Finally, let me briefly say that we think that in the longer term, the first is the third-generation lithium-ion battery, followed by the solid-state lithium battery. The ultimate goal may be solid-state lithium-air battery. This is Chen’s point of view.

The page contains the contents of the machine translation.