The Black Stars lost their last group game 1-0 to Egypt on Wednesday thanks to a Mohamed Salah free-kick, but had already booked their place with six points.
''We wanted to finish top of the Group D table and stay in Port-Gentil but it didn't happen as planned. Now we are going to face Congo DR in the quarterfinals and it is not going to be an easy game,'' Badu said.
''It will be a tough game, Congo are a strong team. They finished top in their group but we are looking forward to the game. We hope to improve on our performance and win the game.
''We will make sure we give out our best to get the result we want since we want to advance and win the trophy,'' he added.
Ghana are likely to miss their captain Asamoah Gyan, who sustained an injury against the Pharaohs and was forced to take an early shower.
The Black Stars medical team will run a scan on him on Thursday, according to reports.
Schalke defender Abdul Baba Rahman has long left the team due to a knee injury picked on opening day against Uganda.