The invention of lithium-ion battery is definitely not Japanese. Otherwise, how can the Nobel prize be given to two Americans and one Japanese. So it's not completely right to say that the lithium-ion battery was invented by the JapaneseLithium ion batteries were first industrialized in Japan, this sentence is right.

We can see from this picture that the Japanese first announced industrialization in 1991, with a market share of 100%. Then it has been falling, and now it is still falling. Even Sony doesn't make lithium-ion batteries anymore. Its lithium-ion batteries were sold to another company. Koreans and Chinese are going up. By 2014, China's market share of power batteries and lithium batteries has surpassed that of Japan and South Korea, ranking first in the world, and is still rising.

Our lithium battery technology is good from the current development situation.In fact, it is a cooperation between academia, engineering and industry. It is the joint cooperation between research institutes and universities. It attaches great importance to the close combination of original innovation, basic research and applied research, and speeds up the industrialization process of research results.

Goodenough found the commonly used cathode materials lithium cobalt oxide and lithium iron phosphate, but both of them have shortcomings. In fact, lithium cobalt oxide can only take out 0.5 mole of lithium, while lithium iron phosphate is actually an insulator, which has its disadvantages. We tried to find out its shortcomings, and then modified it through theoretical calculation and experiment, and obtained a patent right, which played a very important role in the development of our lithium-ion batteries.

A few years ago, the Belgian Minmetals company came to China to collect intellectual property fees for lithium-ion cathode materials, which is said to cost 50000 a ton. The profit of making lithium cobaltate ternary materials may be less than 50000 yuan per ton. They went to Haidian knowledge court to sue us. Later, the Chinese enterprise making cathode materials United Institute of physics settled with them out of court. Because we have this patent, they no longer have the problem of collecting patent fees. It can be seen that it is not our original material, but we have done our work and applied for our patent, which is very good for protecting our own enterprise.

The second example is lithium iron phosphate. It is an insulator. Through theoretical calculation, it is a one-dimensional ionic conductor. If you add chromium, a large ion, to the lithium site, you will block the lithium channel. This is impossible and useless. Later, someone proposed another method of doping sodium at the iron site. When the iron site is doped with sodium, its color turns black and its conductivity increases by several orders of magnitude. Its ionic conductivity and electronic conductivity are very good. Therefore, French and German scientists recognized this work, which is the only feasible way to break the monopoly of foreign original patents on lithium iron phosphate materials. Only in this way can our lithium battery enterprises now use lithium iron phosphate materials in a considerable amount, which is not affected by foreign intellectual property rights.

It can be seen from these two examples,Although we have not made original innovation, it is also very important that we modify and innovate it again.

Just now we talked about two positive materials. Now I'm talking about negative materials. This is our original innovation. Tsinghua University has long applied for a patent for natural graphite as the cathode of lithium-ion batteries. Two years ago, it applied for the National Invention Award, which is equivalent to recognizing that it is our intellectual property right to use natural graphite as the cathode of lithium-ion batteries. Graphite alone is not enough. The capacity of graphite is relatively low, 372 MAH / g. The capacity of silicon is actually quite high. Can silicon be used as the cathode of lithium-ion batteries? I did this job in 1999 and applied for the first patent. Therefore, we applied for the first patent of silicon as negative electrode in the world, which is also recognized by Americans. But it's still quite difficult for you to use it. From a few hundred milligrams to a few hundred kilograms, it took 17 years. In these 17 years, we have gone from articles to technology, then to products, and then to markets.

At present, our raw materials have been basically localized, and the amount of imports has been quite small. At the same time, most of our equipment are also localized equipment, not to mention the technology of employees. Now, basically, we cultivate our own technology.

Article source:China Economic lecture hall