No. An angel cannot know all things by his essence and his intellect must be perfected by some species in order to know things because God alone knows all things by His essence.
The intellective power of the angel extends to understanding all things: because the object of the intellect is universal being or universal truth.
The angel's essence, however, does not comprise all things in itself, since it is an essence restricted to a genus and species. This is proper to the Divine essence, which is infinite, simply and perfectly to comprise all things in Itself.
Therefore God alone knows all things by His essence. But an angel cannot know all things by his essence; and his intellect must be perfected by some species in order to know things.