We reveal an iodine vapor-induced degradation mechanism in formamidinium–lead-iodide-based perovskite solar cells stressed under combined heat and light illumination.

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We report on a particularly stable 3 V all-solid-state sodium–ion battery built using a closo-borate based electrolyte, namely Na2(B12H12)0.5(B10H10)0.5.

A self-passivating cathode/electrolyte interface achieves stable, room-temperature long-term cycling of 4 V-class Na3(VOPO4)2F|Na4(CB11H12)2(B12H12)|Na all-solid-state sodium batteries with the highest reported discharge cell voltage and cathode-based specific energy.