To being a more powerful charger has been released, 7.2 kW and it will be standard on the Premier trim which is the higher end version and is a $750 option for the base model.
https://www.digitaltrends.com/car-reviews/2019-chevrolet-volt-lt-review/
https://www.digitaltrends.com/car-reviews/2019-chevrolet-volt-lt-review/