Praise be to Allah.
Anger is of three types:
1 – when anger is so intense that are person is no longer aware of what he is doing or saying, and becomes like one who is insane or mad. In this case the talaaq (divorce) does not count, according to all the scholars, because he is like one who is insane and mad, who has lost all power of reason.
2 – when his anger is intense but he understands what he is saying and doing, but his anger is intense and he cannot control himself because the argument trading of insults or fighting has gone on too long, so his anger may be intense because of that. In this case there is a difference of opinion among the scholars, but the most correct view is that divorce does not count in this case either, because the Prophet (peace and blessings of Allah be upon him) said: “There is no divorce and no freeing of slaves when it is done by force or in a state of intense anger.” (Narrated by Ibn Maajah, 2046; classed as saheeh by al-Albaani in al-Irwa’, 2047)
3 – mild anger, which is what happens when the husband is upset with his wife, or he is disappointed about something that his wife has done, but it is not so intense that it makes him lose his power of reasoning or self-control. Rather it is the ordinary kind of anger and is mild. In this case the divorce is valid according to the all the scholars.
This is the correct answer regarding divorce uttered in anger, as was stated by Ibn Taymiyah and Ibn al-Qayyim, may Allah have mercy on them.
And Allah knows best. May Allah send blessings and peace upon our Prophet Muhammad.