High-Speed Operando Tomography and Digital Volume Correlation have been used by a University College London-led team to show in real-time how lithium batteries degrade as they are used.
The new method will enable scientists to non-invasively monitor performance loss of lithium batteries and guide the development of more effective commercial battery designs. The technique used to show the degradation was also used previously by the same team to show how rechargeable Lithium-ion batteries fail.
The study was carried out after there was a call from investigators of fire that grounded Boeing 787 Dreamliner at Heathrow Airport in 2013. The fire was caused by the plane’s disposable Lithium battery-powered emergency locator transmitter which sends out a radar signal to locate missing aircraft. The system is designed to work indefinitely until the aircraft is found but the results show the batteries may not be as resilient as they seem.
The study by UCL, Lund University, The European Synchrotron (ESRF), University of Manchester, Harwell Oxford, Oregon State University and the National Physical Laboratory, published in Advanced Science, shows the internal structural damage caused to batteries working under normal conditions in real-time.
Using cutting edge X-ray imaging techniques at ESRF, the team tracked different types of wear and tear which cause performance loss and linked this wear to design features of the commercial battery.
First author, UCL PhD student Donal Finegan (UCL Chemical Engineering), said: “On the outside, the batteries look like they are doing their job normally but inside we saw the structure was undergoing great change. Electrical activity was high in some areas of the cell, whereas it was low in others; layers of electrode material separated and cracked. All of these changes in structure affect the flow of electricity and reduce the performance of the cell.”
Real-time 3D images of active commercial Li/MnO2 disposable batteries were captured using X-ray computed tomography (CT) and advanced digital volume correlation software. The images formed cross-section time-lapse videos showing the damage occurring on the electrodes inside the battery in real-time. Corresponding author, Dr Paul Shearing (UCL Chemical Engineering), said: “Lithium disposable batteries are used for mission-critical systems where recharging is impractical, so understanding the safety and reliability of them is important, particularly given recent high-profile cases where batteries on aircraft have failed. We gained valuable insights that apply to a variety of commercial batteries using this system, showing an effective, non-invasive way for industry to monitor performance and improvements in commercial battery design.”
Donal Finegan, added: “We effectively mapped the activity and strain on the material inside the battery which will help manufacturers predict how a particular battery will perform during operation and over time. We see this is a valuable tool for optimising the material used in commercial batteries, which will improve their resilience.”
Check out the videos through these links: Link 1, Link 2, Link 3, Link 4 and Link 5.