LAUSR

Conjugated carbonyl compounds are deemed as high theoretical-capacity and green electrode materials for lithium ion batteries (LIBs), but subjected to high dissolution and poor electronic conductivity. In this paper, we have successfully synthesized a series of multi-carbonyl conjugated polymers using coupling polymerization reaction and then constructed carbonyl conjugated polymers/carbon nanotube (CNT) hybrid films by vacuum-filtration method. Importantly, the hybrid films could be served as flexible, binder-free and free-standing organic cathode for LIBs, which could deliver high reversible discharge capacity of 142.3 mAh g-1 at 50 mA g-1, good cycling stability with a capacity retention of 74.6 % at 500 mA g-1 after 300 cycles and excellent rate capability (120.6 mAh g-1 at 1000 mA g-1). In addition, the theoretical calculation has proved that the symmetrical conjugated structure can well accommodate with four Li+ ions during electrochemical reaction. Interestingly, the assembled full cell and flexible battery can lighten on the small devices, suggesting its potential to use in bendable or wearable energy-storages devices.