Described as the cleanest and most economical car in the company's history, the M35 Hybrid is designed to balance performance and fuel efficiency.
The car uses an advanced hybrid system that has "a single electric motor/twin clutch arrangement. Innovatively, the first clutch is installed between the naturally aspirated 3.5-liter V6 and the electric motor. The result of this configuration, where all components act on a single prop shaft to the rear differential, is a consistent driving feel under all conditions with linear performance and the ‘direct responses' that the engineers sought." While that sounds kind of vague, Infiniti also stated the electric motor can power the M35 exclusively.

Power comes from a "laminated" lithium-ion (Li-ion) battery pack, which is nearly the same size as a conventional battery pack but offers twice as much energy. The batteries are recharged by the electric motor (it can act as a generator) and an engine energy recovery system (which harnesses power that is typically lost during deceleration and braking).
Source Listcarworld