I find it rather unlikely he was a wife beater considering what I've read about the relationship with his ill wife. It seems far more likely this is gossip spread by folks on a mission to slander great men of the past. If you can't provide any actual evidence backing that claim, you should really refrain from spreading such things IMHO.
https://thebaffler.com/outbursts/surely-youre-a-creep-mr-fey...
Obviously, Wikipedia isn't a reliable source, but it's not particularly contested that Feynman was a wife-beater to Wife No. 2.
Nothing in that paragraph even contests that he did physically abuse her....?
Cruelty can come in many forms beyond physical trauma.
"The divorce had a fleeting life in the national press--not because Feynman was a celebrity, but because columnists and cartoonists could not overlook the nature of the extreme cruelty: Prof Plays Bongos, Does Calculus In Bed. "The drums made terrific noise," his wife had testified. And: "He begins working on calculus problems in his head as soon as he awakens . . . He did calculus while driving his car, while sitting in the living room and while lying in bed at night.""
As far as I can tell they went through that route so they could get a quick divorce and not have to go through a cooling-off period.
It is alleged here on Page 64.
This is testimony of his ex-wife - take that as you will.