Any method capable of depositing thin functional layers onto structured substrates, and especially into nanoporous frameworks, is conferred with a direct relevance towards energy conversion applications. The conformal coating of non-planar samples is a property that uniquely defines atomic layer deposition (ALD), which is why ALD is inherently suited to the preparation of energy conversion devices. ALD achieves a thin film growth by using well-defined surface chemistry. Two or more complementary, quantitative surface reactions performed subsequently and repeated in an alternating manner result in the deposition of a solid in a layer-by-layer fashion. This Thematic Series will certainly provide the reader with novel ideas for exploiting ALD in the energy realm, and spur further original work in this rapidly developing research area. After its industrial application in electroluminescent displays, semiconductor logics, magnetic and semiconductor memory, ALD has the potential to also become a critical tool in the area of energy conversion.