Benzenediacrylates as organic battery electrode materials: Na versus Li†
This paper discusses investigations of a novel Na-based organic battery electrode material, disodium benzenediacrylate (Na2BDA) in comparison with its Li-ion homologue. Li2BDA has previously shown promising battery properties, such as stable cycling and good capacity retention. Na2BDA and Li2BDA are here successfully synthesized and characterized, and investigated as anode materials in prototype Na- and Li-ion battery cells. Moreover, different electrolytes are screened for the Na-battery material, and a useful operating voltage window is explored. Na2BDA is shown to possess a higher initial coulombic efficiency (91%) than the Li-homologue, which is uncommon for sodiated organic electrode materials. The Na-compound shows an initial capacity of 177.7 mA h g−1, which however decreases to ca. 50 mA h g−1 after 20–100 cycles depending on the cycling rate; a significantly lower capacity retention then that observed for Li2BDA. The capacity loss can primarily be explained by a decomposition mechanism of the Na2BDA compound.