Rotten in the Air: Revisiting Cotard's Syndrome

Customized Optical Fiber Birefringent Sensors to Multipoint and Simultaneous Temperature and Radial Strain Tracking of Lithium‐Ion Batteries

“…For the calculations and discrimination of simultaneous temperature and radial strain shifts detected by the FBG-PANDA sensors, Equation (3) was used. In Equations (9)(10)(11) are described the calculated sensitivities and determinants in the matrixial method format for the FBG-PANDA 1, FBG-PANDA 2, FBG-PANDA 3 sensors, respectively.…”

“…[9] Depending on the damage degree or accumulation of dendrites, the SEI layer degradation may lead to an uncontrolled exothermal reaction chain, an event called thermal runaway, leading to combustion or explosion, which will compromise the safety of the battery and its surrounding components. [10,11] Currently, electronic sensors such as thermocouples and thermistors have been used for temperature monitoring in LiBs, being placed on the surface and within the batteries for measurements in their several regions. However, despite being low cost (in the order of tens of Euros), these sensors do not have small dimensions (≈1 cm), are susceptible to corrosion, and are electrically active, not being the best choice to be introduced within the battery cells, still, they present lower spatial monitoring, as only one point can be monitored per sensor location.…”

“…However, to perform such simultaneous monitoring, it is necessary to use different approaches or fiber sensing configurations to discriminate both parameters, as both influence the sensor response, such as by using chirped FBGs, hybrid configuration based on FBGs and Fabry-Perot interferometers, and sawtooth stressor-assisted highly birefringent FBG. [7,10,[17][18][19][20][21][22][23][24] The most used approach has been the use of two optical fibers placed side by side, where the location of the FBG sensors is very close, but in different fibers, one of the fibers being fixed, the FBG being influenced by variations in temperature and strain, and the another is loose, being only subject to temperature variations. During their operation, batteries simultaneously heat up and expand/contract, alternative solutions must be developed to perform better and practical monitoring of these both parameters simultaneously.…”