While lawyers work behind the scenes on a possible plea deal that could allow the 19-year-old R&B singer to avoid jail time, Brown and Rihanna have been in a Los Angeles area studio working on a love song, celebrity website TMZ.com said.
TMZ said the song was originally written for Rihanna before the couple fought on the eve of the Grammy Awards in February. But afterward, music producer Polow Da Don believed the track -- which focuses on overcoming difficult challenges as a couple -- would make a good duet.
The late night sessions were "very, very emotional...the feeling in the room was pure love," an unidentified source was quoted as telling TMZ.
Polow Da Don has worked with Brown in the past, as well as with singers Usher and Fergie.
E! News said Brown was hoping to include the track on his new album due later this year. "They've been working on it together," E! quoted a studio source as saying.
Brown, who had hits with "Forever" and "Run It!", was formally charged last week with punching Rihanna, 21, in the face and biting her ear and finger.
Rihanna and Brown were reported to have reconciled about three weeks after his arrest on the day of the Grammys, although neither have commented on the reports.
Brown has not entered a plea to the charges and his arraignment was postponed for a month, apparently to give lawyers a chance to work out a plea deal.