Is id the correct spelling

Answer 1

The abbreviation "ID" (identification) is also used as a vernacular verb "to identify". The "id" in psychiatry was a Freudian construct supposedly embodying all the "animal" and instinctive drives of the human mind, whereas the "ego" was his intellectual self-awareness.

Answer 2

Yes, "id" is the correct spelling for the Freudian term describing the innate part of the psyche that operates on the pleasure principle.