PBA active materials are characterized experimentally in order to understand their performance. Analytical techniques, such as X-ray/neutron diffraction (XRD/ND), inductively coupled plasma mass spectrometry (ICP-MS) and positron annihilation spectroscopy (PAS), are commonly used to probe the structural and compositional make-up of PBAs . The diffraction methodologies are powerful imparting a multitude of information such as crystal structure, density, vacancy and water content. Because of the highly dynamic and complex nature of the inner-workings of a SIB during dis-/charge it has become increasingly evident that operando techniques are necessary. Operando Fourier transform infrared spectroscopy (FTIR) and XRD have seen success in the field of SIBs, with the latter able to monitor changes in the crystal structure and the former capable of probing changes in molecular bond environment during cycling . Operando gas analysis, in the form of differential/online electrochemical mass spectrometry (D/OEMS), has also seen significant success, however, so far, the majority of work has been centred around LIBs . D/OEMS is a powerful tool to monitor the evolution of volatile species within the battery cell during cycling with high sensitivity (ppb) and accuracy. These volatile species are often the result of electrolyte/electrode degradation and are unique to each battery system under study .