Green energy technologies are urgently needed due to an increasing global energy demand as well as critical environmental and climate concerns associated with the exploitation of fossil fuels. Electrochemical energy devices allowing direct conversion between chemical and electrical energy are of great interest due to their environmental friendliness. Efficient oxygen evolution reaction (OER) electrocatalysts and high-performance anode materials are crucial for rechargeable metal-air batteries and lithium ion batteries (LIBs), respectively. This Ph.D. project aims at using cheap and environmentally friendly iron components for these applications. In the first project, ultrafine Fe3O4 nanoparticles are homogeneously immobilized on 2D Ni based metal-organic frameworks and used for OER, and the structure, morphology and composition of the material are systematically investigated. Electronic structure modulation and morphology changes improve the catalytic activity and are studied via varying the amount of Fe3O4 in the composite. In the second project, a flower-like composite consisting of Fe2O3 nanocrystals coated with iron doped MnOx layers is synthesized by a facile one-pot microwave-assisted heating synthesis. The crystallinity and morphology evolution of the material are studied by characterizing the product at various reaction times. Key factors affecting the morphology such as reaction temperature and atomic ratio of precursors are systematically investigated. The optimized hybrid material exhibits an improved electrochemical performance for lithium ion storage.