Molecular Engineered Safer Organic Battery through the Incorporation of Flame Retarding Organophosphonate Moiety.

Here, we report the first electrochemical assessment of organophosphonate-based compound as a safe electrode material for lithium-ion batteries, which highlights the reversible redox activity and inherent flame retarding property. Dinickel 1,4-benzenediphosphonate delivers a high reversible capacity of 585 mA h g-1 with stable cycle performance. It expands the scope of organic batteries, which have been mainly dominated by the organic carbonyl family to date. The redox chemistry is elucidated by X-ray absorption spectroscopy and solid-state 31 P NMR investigations. Differential scanning calorimetry profiles of the lithiated electrode material exhibit suppressed heat release, delayed onset temperature, and endothermic behavior in the elevated temperature zone.