An imine-rich polymer with enlarged π-conjugated planes for aqueous zinc-ion batteries

Two imine-rich polymers (planar P3Q and linear TDB) were synthesized through a facile method. P3Q demonstrates an enlarged π-conjugated structure, increasing the coordination and conversion of Zn2+. As a result, for aqueous zinc-ion batteries, P3Q exhibits more excellent electrochemical performance than TDB with a discharge capacity of 226 mA h g-1 at 0.3 A g-1 and relatively high capacity retention of 70% after 100 cycles at 0.5 A g-1. The redox energy storage mechanism is also explored by ex situ characterization and density functional theory calculation.