Besides that other suttas better explain?
On an occasion, bhikkhus, when the mind becomes sluggish, it is timely to develop the enlightenment factor of discrimination of states, the enlightenment factor of energy, and the enlightenment factor of rapture. For what reason? Because the mind is sluggish, bhikkhus, and it is easy to arouse it with those things.
I’m also looking for energy enlightenment factor explanation. I can’t find it.
Question: What did sluggish mind in this sutta mean in Pali?
Answer: It’s līnaṁ cittaṁ
The definitions is here for example in Vb 17:
Therein what is “mental sluggishness”? That which is indisposition of consciousness, unwieldiness, drooping, sagging, sluggishness, being sluggish, state of being sluggish, sloth, being slothful, state of consciousness being slothful. This is called mental sluggishness.