Application of spin-echo small angle neutron scattering to study cycling degradation from dendrite growth in lithium-ion batteries

Abstract:
On a global scale the demand for Lithium-ion batteries is facing a rapid escalation fuelled by a number of areas such as electric vehicles, renewable energy storage systems, and consumer electronics. In order to meet these demands current battery technology needs to dramatically improve especially in areas such as overall lifetime and degradation on cycling. However, it is difficult to study the degradation and failure mechanisms in-situ and in-operando and as a result most structural analysis is carried out post mortem using traditional microscopy techniques. These techniques fail to capture the development of the structure and suffer from both a small sample size and limited field of view. Previous work has shown that by developing an in-situ and in-operando cell compatible with small-angle neutron scattering we are able to capture small changes in the lithium morphology indicating dendrite growth. However, the results indicated the presence of larger structures outside the measured q range. To build on this work and further our understanding of dendrite growth, which plays an important role in battery degradation and failure, we propose to use spin-echo small angle neutron scattering which benefits from a much larger length scale range, up to 25 um, to characterise morphology in lithium-ion batteries over repeated cycling.