How many happy families? Analysis of solid-state battery technology

The pursuit of zero-carbon cars is increasingly hot in advanced countries around the world, and the demand for new energy vehicle specifications has become clear day by day. However, the current development of lithium battery technology slows down the cruising range and safety, making the upgrade of new energy vehicles slow, seeing The national standard (specific energy 300Wh/kg@2020) is coming to an end. The specific energy of liquid lithium is limited by inherent safety issues (260Wh/kg has proven to be unable to control safety) and is no longer able to climb, let alone 350Wh/kg in 2025. In the long term, the long-term goal is hard to see. Recently, there have been a number of alarming battery fire accidents in new energy vehicles that forced BMWs, Toyota and other international depots to step out of the tigers. Whether investing, joint venture or joint development, they are only one step ahead of battery technology. A happy earth 'solid battery' is strategically bundled.

However, the industry leaders have spent about 20 years in the input of solid-state batteries, but they are still in an unclear state of chaos. Each cell manufacturer in the battery industry believes in different electrolyte systems, and there is no technological flow or convergence, and some of them have succeeded. Production, and some are constantly delaying the development of roads and roads. It is even more frequent that Hao throws away hundreds of millions of dollars and then leaves the field. The drop in Heaven's hell is due to the difference in the nature of the routes between the various electrolyte systems, in terms of stability, and electricity. Sexual performance and mass production have inherent advantages and disadvantages that are irreversible to the level of modern science and technology. We classify electrolytes into six categories according to manufacturing processes and chemical systems: Oxides, Sulfides, Cyanides, Halides, Thin Films, Polymers, Lists The four major technical lines illustrate their development status:

Solid polymer

Thanks to the development of mature liquid polymers, the production capacity of solid polymer batteries is not far from liquid polymers, but poor stability leads to poor electrical reliability, coupled with the ionic conductivity at room temperature. Poor, battery performance is thus compromised, and even under 10-4S/cm is difficult to operate.

Earlier, the French Bolloré Group used BatScap batteries to distribute vehicles in the city network, but it was necessary to continuously heat the battery of the electric vehicle to 60°C or more to maintain the internal conductive capacity of the battery. The Bosch Bosch Group, the German component giant, also had to declare in early 2018 that Abandoning the investment in Seeo; Recently, Ionic Materialss, the manufacturer of solid polymer electrolytes, has attracted the most attention from Samsung SDI, Dyson, and Wanxiang Group. Perhaps the sample has been available in recent years.

Oxide film

The thickness of thin-film batteries can reach the micron level, which was once considered as the best solution for the medical and wear market. However, it is similar to the semiconductor sputtering production process. The equipment costs are unreliable, the environmental requirements are extremely high, and the yield rate is low, so the volume production is not easy. And the cost is very high.

The US IPS made all-solid-state thin-film batteries in 2008. It was acquired by Apple in 2014 and has not yet published any products. In addition, the Dyson Group's investment in Sakti3 is the hottest news for the 2015 solid-state battery market, but in 2017, All of Sakti3's patents were declared to be abandoned, and the investment in solid polymer plants was shifted to seek rapid entry into the market. From this perspective, the commercialization of thin-film battery production has yet to be observed.


Although the conductivity is good and the stability is poor, it is the largest short board, and the stability of the system is also low. The process technology is complicated, and it is far from the lithium battery process. Therefore, the sulfide system puts in very high resources.

Toyota, SamsungSDI, and CATL have all invested in the development of this system. Toyota expects that its research and development of solid state sulfide batteries will be commercially available in 2022. South Korean battery maker SDI has spent more than 10 years researching on the sulphide technology route and turned to early this year. The solid polymer route, the sulphide route, cannot be proved. It can only be proved by time.


Oxide has the highest stability and can be produced in a relatively low cost process equipment and factory facilities in the general atmosphere.

Sony, Ohara, and Huiengeng Technology are the representatives of this technology line. Among them, Huaneng Technology took the lead in over ten years to overcome the poor conductivity of oxides. During the production of oxidized metal stacks, they are brittle and cracks can break. Such issues as successful commercialization of the “12-minute fast charge” and “dynamically bendable” solid state batteries were applied to HTC, SoftBank and other branded products. Currently, solid state power has been established with several car manufacturers in China, Europe and Japan. Battery market.

in conclusion

At present, all units have a low level of mastery of solid-state batteries and they are willing to share less. Therefore, the battery factory’s choice of technology route is like an unavoidable adventure. Each road has different obstacles to be overcome before departure. Only knowing the theoretical strengths and weaknesses, but seeing all the way through it will be a dead end, and the long road that is still a bumpy ride will be unknown. We can only speculate from the industry's trends that the current fastest-growing oxide is The system, followed by the solid polymer, should be available in recent years; whether the road to commercialization of sulfides and thin-film batteries is feasible, at least five years to be observed, and the oxide system is now available for commercial mass production. .