This paper describes how modularity is implemented in a roadmapping framework so that from a set of stand-alone roadmaps each could be used as an interconnected module, vertically and horizontally perfectly fitting together in an overall integrated roadmap describing a broad landscape of corresponding developments in technologies, products, applications, markets and society. The concept of modular roadmapping is illustrated by the example of a huge roadmapping project accompanying the innovation alliance “Lithium-ion batteries LIB 2015”, carried out by Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe, and funded by the Federal Ministry of Education and Research (BMBF), Germany. The roadmapping framework addresses a broad technology landscape covering three focal domains: (i) Energy storage with lithium-ion battery technologies in general, addressing all kinds of corresponding battery applications, (ii) energy storage for electric mobility and (iii) stationary energy storage specifically. Each domain is represented and specified through a certain technology roadmap covering technological developments, a product roadmap assessing corresponding market trends and product requirements, and an integrated, unified roadmap linking technology push and market pull in a broader integrated view. In order to further specific insights for next generations of batteries in the above-mentioned roadmapping project, modularity for integrated roadmapping helps to systematically link expertise on technologies, products, applications, markets and society in regards to overarching (inter-)national challenges (e.g. the German energy transition). Every roadmap forms an independent module for itself, showing different paths of future development and critical dependencies in each of the three highly dependent but also highly complex domains mentioned. Yet only through the integration of all perspectives in technologies, products, applications, markets and society, the aim of analyzing and documenting changes of innovation systems as a whole can be accomplished. From an academic perspective, a modular design approach in roadmapping contributes to more conceptual clarity, especially when providing roadmaps for a technology-driven innovation system with a core technology in the focus and multiple other competing or complementary technologies around. From a practitioner's point of view, guidance is provided on how to link developments and progression made in basic and applied science, industrial R&D and socio-political trends, for current and emerging technologies and applications. The experience made and insights from various stakeholders involved in this roadmapping project are of interest and relevance for all actors, be they from science, industry or policy, as they may trigger the development of existing and emergence of new industries.