Vehicle-to-Grid (V2G) Research: A Decade of Progress, Achievements, and Future Directions

Vehicle-to-Grid (V2G) technology enables bidirectional power exchange between electric vehicles (EVs) and the power grid, allowing EVs to serve as distributed energy resources that enhance grid flexibility and stability. Its core concept leverages the aggregated capacity of EV batteries to buffer fluctuations from variable renewable energy sources. This study systematically reviews 200 high-impact publications from 2015 to early 2024 to trace shifts in research priorities. Unlike previous reviews that focused on specific technical or social aspects of V2G, this work adopts a quantitative bibliometric approach to provide a broader and more integrated perspective of the field. By mapping representative high-impact studies, it identifies the structural relationships among subfields, reveals the distribution of research hotspots, and tracks their temporal evolution, thereby offering a systematic roadmap for future V2G research. The analysis divides the decade into two periods (2015–2019 and 2020–2024) to capture temporal trends. Findings show a dominant focus on bidirectional charging technologies and V2G network management strategies. Earlier studies emphasized infrastructure integration and regulatory frameworks, while recent research increasingly targets optimization algorithms, communication protocols, and hardware standardization. Three key trends emerge: first, growing regional divergence in interface standards and product design—for example, China prioritizes high-power asymmetric DC interfaces, whereas Europe focuses on lower-power AC systems and interoperability; second, a shift from microgrid-based implementations toward centralized V2G management to support coordinated, grid-level operations; and third, rising emphasis on economic viability models to enable large-scale system deployment.