Thanks to the boom in renewables, these days the limiting factor of the energy revolution is not power supply as much as power storage. Cleaner, greener batteries are needed to charge our cars, e-bikes, and devices for longer.
In the future, a large portion of our energy is expected to come from renewable sources such as solar and wind. Yet we all know that there are times when the wind does not blow and the sun does not shine. To balance supply, we need to store the surplus electricity generated by renewables, until we are ready to consume it. Better batteries are one important way of doing this. If we are to power the envisioned fleets of electric cars and mobility devices, we will need huge numbers of batteries.
If we are to improve them, we need to first understand how they work. Traditional lithium-ion batteries have three key components. There are two solid components called electrodes – the anode and the cathode – and a liquid called the electrolyte. When the battery discharges, electrons stream out of the anode to the cathode to power whatever device it’s connected to. Positive lithium ions diffuse through the electrolyte, attracted to the negative charge of the cathode. When the battery is being charged up, this goes in reverse.
The whole process is a reversible electrochemical reaction. There are many flavors of this basic process with different kinds of chemicals and ions involved. A particular option being explored is to do away with the liquid electrolyte and make it a solid or gel instead. In theory, these solid-state batteries have a higher energy density, meaning they can power devices for longer. They should also be safer and quicker to manufacture, since, unlike typical lithium-ion batteries, they don’t use a flammable liquid electrolyte.