It went from a lab concept to a commercial vehicle.
What is the time from R&D to commercialization of a new ICE?
Just because you're not reading about battery research in the popular press doesn't mean it is not ongoing. Since I know you wouldn't read all of them there is no point in my posting a complete listing for the past 8 years. Here are 3 recent ones as light reading for you:
Enabling 4C Fast Charging of Lithium-Ion Batteries by Coating Graphite with a Solid-State ElectrolyteAdvanced Energy MaterialsBoundary conditions for Onboard thermal-management system of a battery pack under ultrafast chargingEnergyElucidating Cathode Degradation Mechanisms in NMC811/Graphite Cells Under Fast Charge Rates Using Operando Synchrotron CharacterizationJournal of the Electrochemical Society