Thermal Mapping of a Lithium Polymer Batteries Pack with FBGs Network

Abstract

In this paper, a network of 37 fiber Bragg grating (FBG) sensors is proposed for real-time, in situ, and operando multipoint monitoring of the surface temperature distribution on a pack of three prismatic lithium polymer batteries (LiPBs). Using the network, a spatial and temporal thermal mapping of all pack interfaces was performed. In each interface, nine strategic locations were monitored by considering a three-by-three matrix, corresponding to the LiPBs top, middle and bottom zones. The batteries were subjected to charge and discharge cycles, where the charge was carried out at 1.0 C, whereas the discharge rates were 0.7 C and 1.4 C. The results show that in general, a thermal gradient is recognized from the top to the bottom, but is less prominent in the end-of-charge steps. The results also indicate the presence of hot spots between two of the three batteries, which were located near the positive tab collector. This occurs due to the higher current density of the lithium ions in this area. The presented FBG sensing network can be used to improve the thermal management of batteries by performing a spatiotemporal thermal mapping, as well as by identifying the zones which are more conducive to the possibility of the existence of hot spots, thereby preventing severe consequences such as thermal runaway and promoting their safety. To our knowledge, this is the first time that a spatial and temporal thermal mapping is reported for this specific application using a network of FBG sensors.

Operando decoding of chemical and thermal events in commercial Na(Li)-ion cells via optical sensors

“…Based on implanted FBG sensors within a battery, researchers could achieve pouch-cell temperature imaging and relate the monitored signals to some battery events, including short-circuit, SOC, and SOH estimations, while pushing further the physics of such sensors to effectively decouple thermal and strain effects. [14][15][16][17][18][19] However, in spite of the benefits of the established correlations from a physics point of view, the analysis remains orphaned of chemical inputs, hence a missing critical link.…”

Fiber Optic Sensing Technologies for Battery Management Systems and Energy Storage Applications

“…The FBG sensors were reported to have a 0.05 °C higher accuracy and a rise time 28.2% lower than the thermocouples. Then, the same authors conducted a thermal and spatial mapping of a 3-prismatic-cell battery pack combined in series, as shown in Figure 11 , with a total voltage of 11 V and with 37 FBGs on four SMFs [ 143 ]. Under constant current charging at 1 C-rate, a hotspot was detected at the interface between two cells that exhibited higher current density than others.…”

“… Experimental setup of the quasi-distributed temperature sensing system on a Li-ion battery pack using an FBG network [ 143 ]. …”

Toward Better and Smarter Batteries by Combining AI with Multisensory and Self‐Healing Approaches

“…Great hope has been placed over the last 5-6 years in optical sensing since optical fibers, for example, Fiber Bragg Grating (FBG) sensors, provide several advantages relevant to batteries such as low invasiveness owing to their tiny dimensions (Ø < 200 µm), immunity to electromagnetic radiation, resistance to corrosion while being electronic insulators. [102,[107][108][109][110] FBGs simply operate by correlating the wavelength of the reflected optical signal with local temperature (T), pressure (P), and strain (ε), which are essential parameters to improve battery monitoring. Using single fiber and the feasibility to multiplex large numbers of FBGS over a short distance, researchers succeed in decoupling thermal from strain and pressure effects to achieve inside cell temperature imaging.…”