The two teams will meet at the Allianz Arena on Tuesday night, with the return leg in Spain due to be played on Wednesday, May 1.
Ahead of those meetings, full-back Lahm has expressed the importance of his side having an advantage to take to Camp Nou.
"Barcelona have been the team to beat in the last few years and we have to recognise this. I think we stand a good chance of winning and our aim is to do that tomorrow," he told reporters.
"We have a great bunch of players who know what it takes to win. It will be important to get a positive result at home."
Barcelona won 5-1 on aggregate when the two clubs last met back in 2009.