Phase transitions occurring during the (de)intercalation of Na in Na_2/3[Fe_1/2Mn_1/2]O₂ have been examined by using in situ XRD and in situ Raman Spectroscopy along with ex situ NMR.

Insight into the mechanism of Na insertion and extraction into FePO₄–NaFePO₄ based on a detailed in situ X-ray diffraction study, from which interesting new features were identified and analysed.

In this work, a new bulk Li_3.6PO_3.4N_0.6 crystalline polymorph has been prepared from low-cost precursors, following a simple ball-milling procedure. The densified powder exhibits a conductivity of 5.0 × 10^–6 S cm^–1 at 70 °C and an electrochemical stability allowing operation with high-voltage materials up to 5.0 V vs Li/Li⁺. Stripping and plating of lithium in a symmetric cell demonstrates the forthcoming bulk application of LiPON in electrochemical devices. Widening the use of lithium phosphorus oxynitride compositions to bulk solid-state batteries will have relevant implications because of its unique compatibility with both high-voltage electroactive materials and lithium metal and its low density.