The need for high energy density batteries becomes increasingly important for the development of new and clean energy technologies, such as electric vehicles and electrical storage from wind and solar power. The search for new energetic materials of primary and secondary batteries with higher energy density has been highlighted in recent years. This review surveys recent advances in the research field of high energy density electrode materials with focus on multi-electron reaction chemistry of light-weight elements and compounds. In the first section, we briefly introduce the basic strategies for enhancement of the energy density of primary batteries based on multi-electron reactions. The following sections present overviews of typical electrode materials with multi-electron chemistry and their secondary battery applications in aqueous and non-aqueous electrolytes. Finally, the challenges and ongoing research strategies of these novel electrode materials and battery systems for high density energy storage and conversion are discussed.