Toyota is developing a solid battery that can be fully charged in just 15 minutes. The news was recently announced by the automaker’s vice president, Keiji Kaita, during an interview with the Automotive News website. The project is being conducted by Prime Planet Energy & Solutions, a joint venture with Panasonic.
Unlike traditional batteries, this model will be able to transfer lithium ions more efficiently between negative and positive electrodes, thanks to the sulfur-based electrolyte that will be in its composition. For now, companies have developed only one prototype.
More efficiency, greater challenges
Ordinary batteries, like those found in cell phones, have a liquid or gel as an electrolyte – a medium that transports electrons between the anode and the cathode.
The Toyota model, in turn, will have a solid state electrolyte. This has a number of advantages, such as reduced fire risk. Another very important benefit is the increase in efficiency: solid batteries can store up to 60% more energy than a conventional battery of the same volume.
However, during the interview, Keiji Kaita stated that some challenges still need to be overcome. The solid electrolyte needs to be compacted under high pressure to reduce the spaces between the particles, allowing ions and electrons to pass more easily.
On the other hand, this material also needs to be flexible, as the anode expands and contracts during discharge. The central problem is that the more expansion and contraction there is in this system, the greater the deformation of the electrolyte particles.
As a result, the flow of ions and electrons will be inhibited, reducing battery performance in the long run. “The key is to develop a material that is not easily deformed. An innovation can come from new materials or new designs,” says Kaita. According to the executive, production of the model will start in 2025, but in a limited way.