Trends and Evolution of Hydrogen Storage Technology Research: A Multidimensional Analysis Using Bibliometrics and LDA Model

Accelerating the research and demonstration of safe, economical, and efficient hydrogen storage technologies is essential for the development of the hydrogen energy industry. This study examines the development and evolution patterns of hydrogen storage technologies through bibliometric analysis and the latent Dirichlet allocation (LDA) topic model, utilizing different dimensions of literature and patent data. The main conclusions are as follows: (1) Research in hydrogen storage exhibits a three-phase pattern. China accounts for over one-third of the publications, yet the average number of citations per paper is relatively low. Research in the United States shows fluctuations, while Japanese studies, though initiated early, display a gradual growth rate. Conversely, India has experienced rapid development in recent years. In Asian countries such as China, Japan, and South Korea, universities are the primary institutions driving influential research publications. In contrast, government-affiliated research agencies and scientific organizations play a more dominant role in the United States, Germany, and other European countries. (2) There is a growing interest in emerging materials technologies such as metal hydrides, hydrogen storage alloys, metal–organic frameworks (MOFs), and hydrogen storage metal oxides. Carbon capture and storage (CCS) enhance the application potential of hydrogen storage technologies. Interest in fundamental equipment and system integration research is declining, although interest in carbon-based materials, air filtration, and catalytic reactors shows fluctuating growth. (3) Research on hydrogen storage materials has shifted from basic studies to performance optimization and diversification, with system integration increasingly incorporating intelligent technologies. Catalytic technology is moving from precious metals to efficient nonprecious metal catalysts, with two-dimensional materials like graphene showing potential applications. Advancements in green recycling technologies have improved resource utilization efficiency, promoting environmentally friendly hydrogen energy applications.