Lithium hydroxyphenyl propanesulfonate imparts composite solid polymer electrolytes with ultrahigh ionic conductivity for dendrite free lithium batteries

Abstract

Anion chemistry of sulfonates plays a crucial role in dictating the electrochemical performance of composite solid polymer electrolytes (CSPEs), hence affecting the cyclability of lithium-ion batteries (LIBs). The CSPEs received great attention for LIBs, however, simultaneously achieving high ionic conductivity and long cycle life in realistic batteries is still a great challenge. Herein, we report new sulfonate anion with hydrophilic aromatic structure and ether alkyl spacer of hydroxyl wing namely lithium hydroxyphenyl propanesulfonate (LHPS), and a series of CSPEs obtained by coupling of the synthesized anions via tetraethyl orthosilicate to be used in LIBs. The CSPEs comprising LHPS achieve higher ionic conductivity and excellent cyclability with impressive stability due to their decent compatibility of hydroxyl wing, and aliphatic ether spacer with the polymeric matrix. The intramolecular and intermolecular interactions of LHPS with other precursors within anion-polymer matrices via hydrogen bonding reduce anionic species migration, thus augmenting Li+ ion conduction and impeding lithium dendritic growth during the electrochemical performance. This opens a new avenue for designing conductive and long cycle life CSPEs for LIBs in the future.