This is the 18398th most frequent Russian word.
электромобилей
"Electromobiles" or "electric cars."
In this sentence, 'электромобилей' is used in the genitive case to indicate possession or relation concerning the new models.
На рынке появилось много новых моделей электромобилей.
Many new models of electric cars have appeared on the market.
Here, 'электромобилей' is in the genitive case due to its connection to the noun 'покупку' requiring this case to specify the object purchased.
Правительство обсуждает субсидии на покупку электромобилей.
The government is discussing subsidies for the purchase of electric cars.
In this context, 'электромобилей' is in the genitive case because it modifies 'запас хода', illustrating possession or characteristic of the electric cars.