If he won't make a change for himself would he consider it for his kids? This site unfortunately discusses things mostly in terms of male-to-female domestic violence, but the statistics of how kids seem to be impacted might be compelling to him:
Ten Alarming Domestic Violence Statistics
This organization in Maine offers help for all domestic abuse victims, but makes a special point of providing support for men -- they have a support line:
Domestic Abuse Helpline for Men & Women » About the Domestic Abuse Helpline
Kudos to you for trying to help. I hope this isn't taken the wrong way, but are either he or his wife Asian? There is a serious problem with domestic abuse here in China -- very much part of the local culture unfortunately. A very high percentage of kids are abused by their parents, and/or witness abuse between the parents, and it normalizes it for them to some extent. very difficult pattern to change. I know someone doing research and policy work related to this both in the US and China -- I can see if she can suggest resources or approaches that might help convince him to take it more seriously.
A very large proportion of homocides are connected to domestic abuse, and perhaps reminding him of that might also be appropriate.