are there any airliners and or aircraft that use bleed air and excess heat from the engine to prevent icing. Rather than use battery power or alternators, this would make sense from an energy efficiency point of view because the use of alternators and batteries would use more fuels if providing electricity for heaters and recharging the batteries
1 Answer
Quite a few actually, and this has been dealt with here before. Most systems use the bleed air from the engine, which is directed through pipes to wing leading edges, engine cowlings etc.
For example, the Boeing 767 anti-icing system, from this question:
Image from Aircraft Anti-Icing Systems by Leslie Mehl and Annie Parsons
This question has answers which explain about the anti-icing systems in large aircraft.
Boeing 727 anti-icing system, image from this answer