Non-destructive characterization techniques for battery performance and life-cycle assessment

Improving the performance and efficiency of batteries is key to enabling the broader adoption of electric vehicles and the effective use of intermittent renewable energy sources. However, this enhancement demands a more comprehensive understanding and improved surveillance of the essential mechanisms that control battery functionality over their entire lifespan. Unfortunately, from the moment batteries are sealed until their end of life, they remain a ‘black box’, and our knowledge of the health status of a commercial battery is limited to current (I), voltage (V), temperature (T) and impedance (R) measurements, at the cell or even module level during use, leading to an over-reliance on insufficient data to establish conservative safety margins and a systematic under-utilization of cells and batteries. Although the field of operando characterization is not new, the emergence of techniques capable of tracking commercial battery properties under realistic conditions has unlocked a trove of chemical, thermal and mechanical data that have the potential to revolutionize the development and utilization strategies of both new and used lithium-ion devices. In this Review, we examine the latest advances in non-destructive characterization techniques, including electrical sensors, optical fibres, acoustic transducers, X-ray-based imaging and thermal imaging (infrared camera or calorimetry), and their potential to improve our comprehension of degradation mechanisms, reduce time and cost, and enhance battery performance throughout their three main life stages: during the manufacturing process, during their utilization and, finally, at the end of their life.