Solid-state battery failure revealed
Mechanisms that cause lithium metal solid-state batteries to fail have been revealed by Oxford University scientists using advanced imaging techniques.
The researchers involved say that if these failure mechanisms can be overcome, solid-state batteries (SSBs) with lithium metal anodes could deliver a step-change improvement in electric vehicle battery range, safety and performance, as well as advance electric aviation.
Lithium metal solid-state batteries are known to be prone to short-circuit when charging due to the growth of dendrites - filaments of lithium metal that crack through the ceramic electrolyte.
The researchers undertook a series of in-depth investigations into how this short-circuiting happens as part of the Faraday Institution's SOLBAT project.
By using X-ray computed tomography at the UK's national synchotron, Diamond Light Source, the team was able to visualise dendrite failure in detail during charging.
The initiation and propogation of the dendrite cracks are seen to be separate processes, driven by distinct underlying mechanisms. These cracks start when lithium accumulates in sub-surface pores, which when they become full futher charging increases the pressure which leads to cracking. Propogation occurs through a wedge-opening mechanism which drives a crack open from the rear.
According to a recent report by the Faraday Institution, SSBs may satisfy 50% of global demand for batteries in consumer electronics, 30% in transportation, and over 10% in aircraft by 2040.
