GM is working with LG Chem on a new generation of lithium-ion batteries and housings, with new battery modules. The first EV battery design, circa 2010 was a T-shape used in the Chevrolet Volt plug-in hybrid. It took up the space between the seats that would have been the transmission tunnel, as well as under the back seat.
With the Chevrolet Bolt EV, GM switched to a rectangular flat pack, or slice, that formed the bottom of the car (suitably protected from road hazards), with a bump that fit under the rear seat. Internally it’s called BEV2 (main photo) and has 288 cells. On the Bolt EV, it had an EPA range of 238 miles for the 2017-2019 models; tweaks got it up to 259 miles for the 2020 Bolt. The next-generation Bolt is now slated for introduction in 2021 as a 2022 model.