Meet the expert – Professor David Greenwood: What is a Gigafactory and why do we need one in the UK?
What is a gigafactory?
A gigafactory is a huge factory that produces very large numbers of batteries for electric vehicles. Tesla pioneered the concept with their factory in Sparks, Nevada, but they are now being built across the globe.
Why do we need one?
In order to compete internationally and to support the UK automotive industry battery production needs to be scaled up rapidly across both the UK and Europe. This situation is exacerbated by tariffs due to be imposed across the UK and EU unless a certain proportion of a car is produced in one of those jurisdictions.
As an EV battery makes up around half of a vehicle’s weight and about half its cost, it is crucial the UK scales up battery production to supply its car industry.
How are electric car batteries made?
EV batteries come in lots of different shapes and sizes but are all made up of many battery cells put together to form a battery pack.
To make a battery, we take electrochemically active materials, like graphite, nickel manganese, cobalt and lithium, and make powders from them. These powders are mixed with solvents and adhesives, then coated onto metal (aluminium or copper) foils which are then packaged together inside cells. Hundreds, or even thousands of those cells are packaged together, along with a sophisticated control system to make the battery pack of an electric car.
This is a very precise process – otherwise, the quality of the battery is impacted. At WMG, around 20 battery cells per day can be produced for research and development purposes. At a gigafactory, production would be closer to 20 cells per second to go into cars.
How are batteries recycled?
At the end of life, EV batteries are collected, discharged and shredded. The materials are separated into metals, polymers and “black mass”. The metals and polymers are recycled in the usual way, and the black mass is treated using either pyrolysis (fire) or leaching (acids) to extract the valuable materials like cobalt, nickel and manganese. At the moment only about 50% of the battery is recovered, but WMG is working on ways to get this closer to 90%. With 11 million tonnes of lithium-ion batteries expected to need recycling by 2030, the need to build domestic capacity to recycle them is greater than ever.