According to foreign media reports, Nissan's solid-state battery research and development team is overcoming the challenges brought by solid-state batteries, saying that the energy density of solid-state batteries is twice that of lithium-ion batteries, and the charging time is one-third of that of lithium-ion batteries, the cost per kilowatt-hour is $75, and it will be reduced to $65 in the later period. If all goes according to plan, Nissan will achieve mass production of solid-state batteries in 2028.
Kazuhiro Doi, Nissan's vice president of advanced battery research, said, "Solid-state batteries have twice the energy density of current lithium-ion batteries, and if something major happens, it could be even more catastrophic than today's batteries." But Doi insists Nissan can now overcome safety concerns and other key challenges that make solid-state batteries difficult to deliver. Nissan has committed to bringing to market lighter, smaller, and more energy-dense batteries.
Nissan believes that this breakthrough will help the company launch electric models in segments such as pickup trucks, large SUVs and even sports cars, for which the weight and size of batteries are an issue. Doi noted, "I think all-solid-state batteries can change the game in the electric vehicle industry. ”
Makoto Uchida, CEO of Nissan Motor Co. Image source: Nissan
For now, Nissan is only taking the first step towards this goal. Nissan has a solid-state battery feasibility study laboratory and is experimenting with hand-manufactured, small-scale batteries. But if all goes according to plan, Nissan will start a pilot plant in 2024 and achieve mass production in 2028.
Kenzo Oshihara, Nissan's deputy general manager for innovative battery production, said that Nissan's laboratory can only produce about 50 four-layer soft-pack solid-state batteries per month, while only one electric car needs about 5,000 soft-pack solid-state batteries. Oshihara revealed, "Nissan's laboratory will take a long time to realize the production of solid-state batteries for vehicles, and the equipment for mass production must be more sophisticated." ”
Image source: Nissan
Nissan's challenge lies in technology and manufacturing. First, Nissan is still exploring the correct chemical composition formulations for cathodes and anodes. Nissan has a partnership with nasa to search for valid material combinations in the agency's vast battery database. Nissan believes it can use artificial intelligence to screen formulations and shorten the research time from 5 to 20 years to 2 to 3 years.
Nissan is also focused on exploring cobalt-free cathodes, possibly using abundant, inexpensive sulfur or manganese, Doi said. In terms of anodes, Nissan sees potential for silicon-based or lithium metal compounds.
Then there are the strict standards for producing solid-state batteries. First of all, the slurry must be beaten very finely to maximize the conductivity of the battery. Second, the cathode-electrolytic-anode layer must be precisely arranged. In the process, Nissan must also increase the speed of all procedures in order to achieve mass production. Doi mentioned, "These procedures are all related to the cost and speed of production of solid-state batteries, which is a more complex set of technologies than traditional lithium-ions." ”
Image source: Nissan
Nissan has overcome several challenges. Nissan has adopted an adhesive on the cathode that reduces drag and improves the movement of lithium ions. Engineers have also discovered a material that can inhibit the formation of twig crystals, which short-circuit the battery. They also found a design that allows the electrolyte and electrode interfaces to expand and contract repeatedly, but the interfaces do not separate. On top of that, Doi's team revealed that it has cracked the puzzle of fast charging at low temperatures.
While more and more startups and suppliers are trying to get into the solid-state battery space, Nissan believes that going it alone and doing it alone has an advantage over collaboration, at least initially. Speaking about external suppliers, Doi said, "They don't have the mature technology to work with automakers like us. ”
Nissan wants to control the know-how in areas such as solid-state battery design and manufacturing, "which will be our core competitiveness in the field of solid-state batteries." However, Nissan only has a few years to figure out the formula for solid-state batteries and achieve cost reduction goals by 2028 by using cheaper materials and streamlining production processes. Doi said, "As long as we work hard, we can do it." ”