Technology context: A range extender generates electricity on board a vehicle to supplement battery power. It can reduce charging dependence for some use cases but adds mechanical complexity, fuel use and maintenance requirements. The videos below illustrate concepts rather than verified volume-production results.
Aquarius engine-generator
The biggest question or tease that Mazda has shared is the use of a rotary engine to be used as a range extender in a hybrid form instead of pure EV.
Next Generation Military Portable Electric Generators, Market Analysis