Traditionally, material characterisation of novel cell chemistries are first studied in half cell configurations, ie against an (alkali) metal counter electrode, to derive fundamental information such as capacities, voltage profiles and related structural changes of the material.

In potassium-ion batteries, this approach causes issues that are associated with the high reactivity of potassium metal counter electrodes. In fact, it can be shown that common positive electrode materials, specifically Prussian Whites, show additional electrochemical features from crosstalk-induced side reactions. Hence, removing potassium metal from cell set-ups is an important step towards more reliable (electrochemical) material characterisation in this cell chemistry, and highlights the need for revised testing protocols and stable reference electrodes.

In this presentation I will provide an overview of the parasitic reactions in potassium-ion batteries and their role in irreversible losses and self-discharge processes, using a combination of electrochemical, photoelectron spectroscopy and gas chromatography techniques. Lastly, I will demonstrate how the use of ‘diagnostic electrodes’ as reference and counter electrodes could potentially provide a more unbiased view on the degradation processes of the highly reactive potassium-ion system.

Everyone is welcome. Complimentary hot drinks and biscuits will be available from 3:30pm.