Lithium-ion batteries are based on a multi-scale electrochemical-thermal-mechanical-side reaction coupling model. This model investigates the structure-property relationship among materials, processes, structures, and performance, enabling computational simulation of the entire battery process, guiding battery design, and accelerating the rapid iteration of battery technology. Based on online monitoring and state evolution analysis of thermal, mechanical, gaseous, and electrical factors, multiple intelligent sensing technologies for batteries have been developed to enhance the estimation accuracy of the battery's true state. This allows for real-time diagnosis and early warning of battery faults such as thermal runaway, lithium deposition, internal short circuit, and aging.