Review of Local In Situ Probing Techniques for the Interfaces of Lithium-Ion and Lithium-Oxygen Batteries

Electrodes in lithium-ion and post-lithium-ion batteries are made of composite materials exposing a variety of different surfaces towards the electrolyte. This causes a distribution of current densities and consequently locally different changes of interfaces and bulk materials that might be critical for the performance and durability of secondary batteries. The optimization of local structures of battery materials is hindered by a lack of local techniques that provide in situ reactivity information from such hidden interfaces. A variety of new electrochemical scanning probe techniques are currently adapted to the investigation of battery materials under near-realistic environmental conditions. The review provides a critical assessment of this development with a particular emphasis on the assessment of the passivating properties of solid-electrolyte interphases, the extension of the concepts to lithium-oxygen cells, and attempts to image ion intercalation reactions.