The capacity has reached the highest level in the world! Japan's Toko University solid-state battery has made a new breakthrough
Japan's Tokyo Institute of Technology has increased the capacity of all-solid-state batteries to the highest level in the world.
Recently, a research team composed of Ryotji Kanno, a distinguished professor at Tokyo Institute of Technology in Japan, and others have successfully improved the fast charging performance and capacity of all-solid-state batteries. The research was made possible by the new development of basic materials and the re-study of manufacturing processes, and the related article was published in the American journal Science.
All-solid-state batteries are a new type of battery. Unlike other batteries, there is no liquid electrolyte, but polymers, oxides, or sulfides are used as solid electrolytes.
The global solid-state battery is still in the research and development stage, and the main technical difficulties include the fact that the ionic conductivity of the solid electrolyte is greatly reduced, which affects the charging performance, and the contact between solid electrolytes is poor and the internal resistance is large.
The above-mentioned research of the Tokyo Institute of Technology in Japan has designed and developed a solid electrolyte with high ionic conductivity using high-entropy materials, which can shorten the battery charging time by increasing the composition complexity of known lithium fast-ion conductors, so that the lithium-ion conductivity is about 2.3-3.8 times that of traditional materials. This means that the indicators that affect the charging performance of the battery can be increased by up to 3.8 times compared with the current traditional battery, which is currently the highest level in the world.
In addition, the research team has improved the manufacturing process to use lithium metal instead of traditional graphite for the anode, so that the cathode capacity per unit electrode area is 1.8 times higher than the current one. The trial all-solid-state battery has a battery capacity of more than 20 milliamperes per square centimeter of electrodes, which is also the highest level announced in the world.
Battery capacity is one of the important performance indicators to measure battery performance, which indicates the amount of power emitted by the battery under certain conditions, usually in Ah. The greater the capacity of the battery, the higher its energy density.
Energy density refers to the amount of energy stored in a certain space or mass substance, and is also an important indicator of battery performance. At present, lithium batteries with ternary cathode materials have an energy density of up to 350 Wh/kg.
In the current power battery market, liquid lithium batteries still dominate. Sun Shigang, an academician of the Chinese Academy of Sciences, once said that the energy density of existing lithium batteries is close to the theoretical limit. In the past decade, the energy density of liquid lithium batteries has increased by 2-3 times. Compared with liquid lithium batteries, solid-state batteries have the advantages of high energy density, high safety and long service life, and are widely regarded by the industry as the next generation of power battery technology.
In 2022, NASA announced that the energy density of its successful solid-state battery reached 500 Wh/kg, and in March this year, Xiaomi announced that it had made three advances in the research and development of solid-state batteries in the laboratory, exceeding the energy density of solid-state batteries to 1000 Wh/L.
In recent years, some new achievements in solid-state batteries have emerged in the academic community, including many Chinese scientists.
In 2021, Li Xin, a Chinese professor from Harvard University, and his student Ye Luhan developed a new multi-layer structure lithium metal solid-state battery, which can be reused 10,000 times and can be charged in as fast as 3 minutes. Their research paper, published in the journal Nature in May 2021, describes the principles of this new solid-state battery.
In 2022, a team of scientists led by Professor Naoaki Yabuuchi of Yokohama National University in Japan developed a new cathode material with extremely strong stability, and thus developed an all-solid-state battery. The research results were published in Nature Materials, a sub-journal of the journal Nature.
According to Guangming Daily, Professor Ma Cheng of the University of Science and Technology of China has designed and synthesized a new type of solid-state electrolyte - lithium zirconium oxychloride, which has the same comprehensive performance as the most advanced sulfide and chloride solid electrolyte, but the cost is less than 4% of the latter, which is suitable for industrial application. The study was published on June 27 this year in the internationally renowned academic journal Nature Communications.
On the road to the industrialization of solid-state lithium batteries, Japanese companies are more aggressive. At the beginning of June this year, Toyota announced the latest plan for the commercialization of solid-state batteries, and by 2027 at the earliest, Toyota will put electric vehicles equipped with solid-state batteries on the market, which can travel about 1,200 kilometers in less than 10 minutes.
Nissan plans to launch its first production model equipped with solid-state batteries in 2028, and Honda plans to launch a pilot production line for solid-state batteries in 2024, which will be used in models launched in the second half of the 2020s, with an investment of 43 billion yen (about 2.1 billion yuan).
At present, there are also a number of battery companies, vehicle companies and scientific research institutes in China, which have laid out the upstream and downstream of the solid-state battery industry chain. However, due to the technical difficulty and high cost of all-solid-state batteries, most Chinese companies have adopted a gradual R&D route from semi-solid-state to solid-state, and the progress has been announcedMost of them are concentrated in semi-solid-state batteries。
According to incomplete statistics, in the A-share market, there are more than 60 listed companies in the solid-state battery industry, represented by CATL (300750.SZ), Ganfeng Lithium (01772.HK), Weilan New Energy, Qingtao Energy, etc., all of which have realized the industrialization of semi-solid-state batteries.
Semi-solid-state batteries are hybrid solid-liquid lithium batteries, and the cells contain a part of the liquid electrolyte, accounting for about 5%-10%.
Weilan New Energy delivered the first batch of semi-solid-state battery cells to NIO in early July this year, with an energy density of 360 Wh/kg.
Qingtao Energy disclosed at the beginning of this year that the semi-solid-state battery developed in cooperation with SAIC will be applied to the new model of SAIC's own brand within the year, with a range of more than 1,000 kilometers, and plans to achieve large-scale mass production in 2025.
According to Gaogong Lithium data, China's solid-state battery shipments in 2022 will be about 0.4 GWh.
China Post Securities said that solid-state batteries are currently in their infancy, and industrialization still takes time. It is estimated that China's solid-state battery shipments will reach 251.1 GWh in 2030, and the market size is expected to reach 20 billion yuan.
