Review of Energy Technologies for Unmanned Underwater Vehicles

As critical platforms for long-endurance ocean exploration, unmanned underwater vehicles (AUVs) play an increasingly vital role in marine surveying and resident observation. However, in extreme deep-sea environments, their energy systems face severe constraints imposed by hydrostatic pressure and thermodynamic conflicts within confined spaces. Therefore, developing energy technologies with high energy density, intrinsic safety, and high-pressure adaptability is of paramount importance. This paper provides a comprehensive review of the multi-physics coupling issues in deep-sea energy systems and the research progress of current mainstream deep-sea energy technologies. Based on energy sources and conversion principles, existing technological paths are categorized into four classes, with a detailed assessment of their performance and bottlenecks in deep-sea environments. Finally, the paper outlines key future development directions for deep-sea energy systems to provide reference for subsequent research.