Mechanics of pressure and temperature in lithium-ion cells based on a fiber Fabry–Perot cavity and Bragg grating

A compact gas pressure and temperature sensor based on a Fabry-Perot interferometer (FPI) and fiber Bragg grating (FBG), which is used inside a cell, is proposed and experimentally demonstrated, and it is successfully applied to the measurement of internal temperature and pressure of cells. The experimental results show that the sensor's sensitivity for pressure and temperature is 5.026 nm/MPa and 0.17 nm/°C, respectively. The designed sensor has good linearity and stability, and it enables the measurement of pressure and temperature under different working conditions of the cell, which provides data support for cell health management and early danger warning.