I'm curious what's actually been done here, because a regular hybrid is just an efficient gas powered vehicle - so you could have any range you want by sizing the tank appropriately. The Prius Gen 2 (my car) has a 45L tank, which is smaller then equivalent Toyota vehicles in that size range and good for about 800km.
I imagine that under the right test conditions, if you were using a plug-in hybrid design and have a fairly substantial battery pack, then it would be different - because then you're just using EV mode for part of the range, and the gas for the rest of it (and choose your speed for optimal ICE performance vs. drag losses).
The battery, because at the end of the day BYD is a battery manufacturer.
Most PHEVs are Hybrid ICE first and battery second. BYD's is the other way around because Japanese companies didn't ToT Hybrid engine technology in the 2000s unlike battery tech (BYD's was initially a ToT JV by Panasonic EDIT: NTT, Sony, and Sanyo. CATL was TDK and Panasonic).
The article discussed here plainly states that the batteries in the hybrid cars are about 10 and 16 kW. The article you link is about the technology being used in buses, with capacity up to 500 kW giving buses ranges of up to 600 km...
I imagine that under the right test conditions, if you were using a plug-in hybrid design and have a fairly substantial battery pack, then it would be different - because then you're just using EV mode for part of the range, and the gas for the rest of it (and choose your speed for optimal ICE performance vs. drag losses).