This paper discusses a project of Participatory Action Research (PAR) on lower secondary chemistry education. In this ongoing project, practicing teachers and university researchers in chemical education jointly carry out projects for developing and evaluating new lesson plans. The focus of the PAR group is to develop teaching/learning activities that are student-centred, integrate new media in the classroom, and invest on cooperative learning methods. The present attempt aimed to develop a context-based and cooperative learning approach for teaching electrochemistry to tenth-grade students, and the paper summarizes these activities, and the results from their testing and evaluation. Implications for teaching/learning in lower secondary chemistry are also discussed.