Opinion: Why do we want solid-state EV batteries? Car News

You may have spotted some stories in the newspapers lately, about revolutionary battery technologies for electric vehicles. Distance anxiety will be a thing of the past, EVs will be recharged in a matter of minutes, and so on.

Do the complaints hold up? Seems like the alternatives to what we have today are well understood and several companies are saying they are close to a breakthrough.

There appear to be two key changes that could improve the capacity and charging speed of lithium-ion batteries if they can work. One is a change in the material used for the battery’s negative electrode, the anode, and the other is a more radical shift to solid-state technology.

The anodes are largely made of carbon in the form of graphite, where lithium ions are stored when the battery is fully charged. This is not the ideal material, as others store more energy, but their use has so far proved technically unfeasible. Switching to an alternative such as a silicon-based material can increase charging speed and capacity, meaning that the existing lithium-ion battery format can be significantly improved – if battery developers can find a way. to make it work in mass production.

The other approach is to switch to a new design, the lithium-ion solid-state battery. In this case, the flammable liquid electrolyte is replaced by a thin solid electrolyte which takes up less space and is flammable. It also means that the graphite anode could be replaced with a lithium metal anode, increasing the capacity and speeding up the charging process.

Lithium metal anodes cannot be used for the existing battery format because they produce tentacle-shaped dendrites that propagate through the liquid electrolyte to the cathode, causing a short circuit and fire. In a solid-state battery, the solid electrolyte prevents this.

Either approach could be a game-changer, provided solid-state batteries are lighter and safer than the existing format. Battery tech developers have been working on the case for at least a decade, and Toyota and Volkswagen recently said they are on the cusp of producing viable EV batteries.

So yes, it’s likely that many players are close to a breakthrough, not just one or two headliners. Let’s just hope that the charging infrastructure can keep up.

READ MORE

Under the Skin: Solid State Batteries Could Be EV Gaming Levers

BMW promises solid-state battery by 2025

On the road to 2030: the state of current technology and what is needed for the future