How is she redeemed? If she is taken captive, he is obligated to redeem her, and is not permitted to say to her: Here is your divorce document and your ketubah, and redeem yourself. And even if he says: I will not redeem you and I will not take the fruits [produced by your property], we do not listen to him, but rather he is obligated to redeem her.
A husband is not obligated to redeem his wife for more than her value, rather [he redeems her] for what she is worth, like all captives. Rem"a: And some say that a wife is equated with his body, and he is able to redeem her with all that he has. (Tur and the Rosh in the name of the Rimah brought in the Beit Yoseif)
If the ransom was higher than her dower, and so he says: "I hereby divorce her, and here is her dower. She may go redeem herself," we do not heed him. Rather we compel him to redeem her, even if her ransom was up to ten times the value of her dower, and even if he only has enough to redeem her. When does this apply? The first time. But if he redeemed her and she was captured a second time, he may divorce her and give her dower to her, and she redeems herself. Rem"a: And regardless, he is not obligated to redeem her a second time (Beit Yosef).
If one's wife was captured while he is abroad, the court enters his property, sells it at auction, and redeems her as the husband redeems her. Rem"a: If he and his wife are both in captivity, see Yoreh De'ah no. 252.
If one banned his wife with a vow that causes him to be obligated to divorce her and pay her dower, and she is captured after he took the vow, he is not obligated to redeem her, for from the moment he vowed he became obligated to divorce her and pay her dower.
If a Kohen's wife is taken captive, even though she becomes forbidden to him, since before this time she was permitted he must redeem her and return her to her father's house. Even if he is in another city [from her father], he must care for her until he returns her to her country, and [then] he divorces her and pays the full Ketubah. If her husband is an Israelite, such that the captive woman is permitted to him, he takes her back as his wife as she was before, and if he wishes he may divorce her later and giver her her Ketubah. Rem"a: A captive woman who is prohibited even to her Israelite husband, that is, in a case where we are concerned that she willingly submitted to intercourse, as is explained in (Shulchan Arukh, Even HaEzer 78:7) - her husband is not obligated to redeem her.
A woman who was [previously] prohibited to her husband by a negative precept in the Torah, who is then taken captive, poses no obligation for her husband to redeem her. He instead gives her her Ketubah and she redeems herself. Rem"a: He must repay any profits that he consumed from her property.
He is only obligated to redeem her [from captivity] in his lifetime. But his widow cannot be redeemed through his property. Even were she captured in his lifetime, but he died before he could redeem her, the inheritors are not obligated to redeem her, even the yibbum she is tied to. Rather, she should be redeemed on her own, or she can collect her ketubah and redeem herself.