Recharging the battery industry

By Mariusz Bogacki, Researcher and Science Communicator, Edinburgh

At its most basic, a battery is a box filled with a complex mixture of chemicals. Most of today’s batteries are built using the lithium-ion, or lit-ion, formula. A lit-ion battery is built of four main components: two electrodes (cathode and anode), separator and liquid electrolyte. The job of the liquid electrolyte is to move ions from the negative electrode (cathode) to the positive electrode (anode) during discharge, and back when charging. Lit-ion batteries have proven successful as they are small, light and relatively powerful. They are currently used to power everything from our mobile devices to electric cars.

Unfortunately, as our reliance on electronics grows, we need to find new ways of producing more efficient and greener batteries. Most of today’s batteries are produced using the same methods as half a century ago, relying on unsustainable natural resources extraction and suffering from low recyclability. If batteries are to compete with the petrol engine and help us tackle the climate change, they need to be more durable and produced from environmentally friendly components.

Let’s take a look at two types of batteries that are promising to transform the conventional battery production.

Silicon Lithium-ion Battery
In traditional lit-ion batteries, anodes are made out of carbon (usually graphite). Regrettably, while very reliable, the efficiency and longevity of this material is quite poor. The extraction of it from earth is also not sustainable. Researchers at Enovix, an American battery company, have challenged the use of carbon by replacing it with silicon, which can be sustainably produced from barley husk ash. Silicon has three times the energy density of carbon and could effectively store up to 50% more energy than what the current carbon-based lit-ion batteries offer. Silicon is also much lighter, promising a more lightweight and compact electronic device. The company has already started to produce the silicon batteries for consumer electronics and is hoping to expand its offering to the electric car market in the near future.

Solid-State Lithium-Metal Battery
Another way of transforming conventional battery production is being offered by Quantum Scape. The company has been experimenting with replacing the carbon component of the anode with lithium metal. It has been long established that such solution could double the density of the battery, beating even the efficiency of the silicon anode. However, until recently such a solution proved unsafe as the chemical reaction triggered during charging could cause a fire or even an explosion. The researchers at Quantum Scape believe that the key to this problem lies in replacing the liquid electrolyte with a solid electrolyte. Made from ceramic material, the solid electrolyte is proving to be very safe and efficient, allowing the ions to move much faster than in the conventional battery. Current tests indicate that that solid-state batteries utilising ceramic-based electrolyte are significantly more cost-effective, have a better life performance and are capable of recharging in only 15 minutes. The company is aiming for the batteries to be used in electric cars and is planning a mass roll-out of it in the coming years.

Batteries are an enabling technology – meaning that they can make a difference in many industry sectors and transform economies. It’s not an exaggeration to say that better batteries are one of the keys to slowing climate change. These recent developments are sure to re-charge the interests in new battery solutions.