To conclude our overview of optical sensors, we'd like to talk about thermo-luminescent probes, whose operating principle is based on the deposition of nanometric thermo-luminescent materials on an optical fiber, which can then be injected into batteries. One of the advantages of this technique is that the luminescence signal depends solely on temperature. Another advantage is the possibility of using multi-luminescent materials, offering the possibility of independently monitoring variations in temperature and Li concentration within a battery, by selecting the appropriate excitation and emission wavelengths.
Diagnostic techniques (optical or acoustic) enable us to identify the phenomena behind the premature degradation of today's commercial batteries: mechanical fractures of electrodes, dissolution of deposits or changes in morphology. It is then up to us to find solutions to remedy these problems. This diagnostic approach is therefore inseparable from a healing stage. Equipping batteries with self-healing systems, in order to improve their lifespan, is a field of experimentation that is being enriched in the literature, as will be shown. Largely inspired by natural processes such as wound healing or specific antibody-antigen recognition, such functions require recourse to supramolecular chemistry. Due to time constraints, what will be covered in this lecture will only be an appetizer for the 2022 session, which will be totally dedicated to this issue.
