Adjei played for TP Mazembe from November 2012 to 2017. He was a member of the team that participated in the 2015 FIFA Club World Cup after TP Mazembe had been crowned champions of Africa after winning the CAF Champions League in 2015. During this competition organized in Japan, he played in the match against Club América which ended in a 2–1 win. After playing for the Kinshasa club for 5 seasons, he left the club in December 2017, after his contract with the club expired.