Nonintrusive thermal-wave sensor for operando quantification of degradation in commercial batteries

Abstract

Monitoring real-world battery degradation is crucial for the widespread application of batteries in different scenarios. However, acquiring quantitative degradation information in operating commercial cells is challenging due to the complex, embedded, and/or qualitative nature of most existing sensing techniques. This process is essentially limited by the type of signals used for detection. Here, we report the use of effective battery thermal conductivity (keff) as a quantitative indicator of battery degradation by leveraging the strong dependence of keff on battery-structure changes. A measurement scheme based on attachable thermal-wave sensors is developed for non-embedded detection and quantitative assessment. A proof-of-concept study of battery degradation during fast charging demonstrates that the amount of lithium plating and electrolyte consumption associated with the side reactions on the graphite anode and deposited lithium can be quantitatively distinguished using our method. Therefore, this work opens the door to the quantitative evaluation of battery degradation using simple non-embedded thermal-wave sensors.

Towards Long-Term Monitoring of Commercial Lithium-Ion Batteries Enabled by Externally Affixed Fiber Sensors and Strain-Based Prognostic Strategies

“…Package-level measurements can be used to monitor temperature changes 10 and the volumetric changes of the cell due to regular (de) intercalation of Li-ions (from)into the electrodes or the irreversible expansion-inducing effects, such as gas build-up, 11,12 the growth of solid-electrolyte interface (SEI) film, 13 and Li-plating on the anode surface. [14][15][16] Importantly, methods that rely on outputs such as terminal voltages and cell capacity [17] may fail to identify anomalous behavior at the earliest stages; hence, alternative quantitative metrics like cell expansion [18] and localized temperature changes may telegraph cell behavior in ways that are currently unrealized and unutilized.…”