Neutron depth profiling (NDP) offers unique advantages in the measurement of element depth distributions, characterized by its high sensitivity and non-destructive nature. This article presents an overview of the principles and data processing methods employed in NDP technology, followed by a comprehensive comparison of various NDP devices and their corresponding parameters on a global scale. Furthermore, potential avenues for upgrades of NDP devices are explored. Given the remarkable sensitivity and non-destructive attributes of NDP technology in detecting ⁶Li, it proves particularly well-suited for in-situ measurements in lithium batteries, rendering it an invaluable tool for research in this field. The article underscores the application of NDP in lithium battery research whilst its utilization in high-temperature alloys, semiconductor materials, and nuclear materials is introduced as well.