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There’s no point reinventing the wheel. Lithium batteries are now a mature technology and firmly in the hands of the Chinese industry. We might as well take another route. Toyota, the world‘s largest car manufacturer, has revealed in recent weeks that it is close to a breakthrough in the production of a potentially revolutionary technology: solid-state batteries, in which the electrolyte that connects the cathode to the anode is not liquid , as in lithium ion batteries currently on the market, but solid.
Not surprisingly, since the first announcement in June, its market capitalization has increased by $26 billion. In fact, if the announced turning point were real, Toyota could start selling safer electric vehicles as early as 2027, capable of recharging more quickly and traveling 1,200 kilometers on a single charge. The transition could be as epochal as that from landlines to cell phones.
The solid-state battery is a sort of Holy Grail of energy research and the race to be first on this front started many years ago. Toyota isn’t the only company investing in this technology. Nissan and Honda have their own programs. South Korea’s three major battery makers – LG, Samsung and SK – have all declared their intention to put solid-state batteries into production by the end of the 2020s. US startups QuantumScape and Solid Power, partners of Volkswagen and BMW, have similar targets for their technology. Even Dyson, the king of vacuum cleaners, is actively participating in the race.
Akitoshi Hayashi, professor at Osaka University and one of the leading experts in the sector, claims that it will be “extremely challenging” to mass-produce solid-state batteries with the same quality as current lithium-ion batteries, but if made they will be “unbeatable at global level”. If Toyota or anyone else manages to make them, the impact would be dramatic for the automotive industry, where sales of electric vehicles and batteries are currently dominated by Tesla and China’s BYD and Catl. It could also enable the electric transition of new sectors, such as aviation. It would also have important geopolitical implications: according to the IEA, last year China produced over 75% of batteries globally and solid state could be the only way to overtake Beijing.
Solid-state batteries differ from current lithium-ion technology mainly in the electrolyte. Several materials are being tested as potential solid electrolytes, including polymers, oxides, and sulfides. The advantage, in addition to the greater safety of the device, is the doubling of the autonomy for a fraction of the costs. Most liquid electrolytes, in fact, are flammable and to avoid misfortunes a series of safety systems must be added, as well as avoiding completely charging and discharging the battery, with a significant waste of capacity. All this adds weight and costs, which are avoided in the solid state. In addition to electrolyte replacement, this technology would also enable another important development: lithium metal anodes. Replacing the graphite used in current anodes, on which Beijing has just imposed export restrictions, would help double the autonomy. Solid-state batteries, however, must overcome important difficulties, such as the formation of dendrites and encrustations that can lead to device failure. Another challenge is maintaining stable contact between solid materials.