Multi carbonyl polyimide as high capacity anode materials for lithium ion batteries

Organic materials are prominent alternative materials for lithium-ion batteries due to their stable cycling, large flexibility, high capacity and various molecular structures. Here, we report a multi carbonyl polyimide material with six carbonyl groups per polymer unit denoted as PMTA, showing super high lithium intercalation capacity and favorable cycling performance as lithium-ion anode material. The as-synthesized PMTA can deliver a capacity of 1638 mAh g(-1) at current density of 100 mA g(-1), and remain a reversible capacity of 698 mAh g(-1) after 50 cycles at a temperature of 30 degrees C. Excellent durability, capacity and reversibility can also be observed at 60 degrees C. The as-prepared PMTA anode electrode material can embed 22 lithium-ions per polymer unit, displaying a theoretical specific capacity of 1704 mAh g(-1), maintaining a discharge capacity of 994 mAh g(-1) after 500 charge and discharge cycles at current density of 1000 mA g(-1) at 60 degrees C, and a coulomb efficiency of approximately 99%. The outstanding performance of the as-synthesized PMTA suggests that introduction of more carbonyl groups will be an effective way to promote lithium intercalation capacity and realize the practical application of high energy density polymer electrodes materials for lithium ion batteries.