High-potential and Stable Bipolar Cathode for Rechargeable Batteries with Fast-charging and Wide-temperature Adaptability

Abstract

Organic carbonyl compounds have been recognized as promising electrodes due to multiple active sites, abundant element resources and flexible structural designability, while their practical applications are still hindered by the easy solubility and low discharge potential. Herein, a novel bipolar polymer composite (TAC) was well-designed by grafting p-type triphenylamine units onto n-type anthraquinone to form an extended π-conjugated structure and in-situ growing on carbon nanotubes, which was proved not only with higher discharge potential but also effectively suppress the dissolution issues. Moreover, TAC combined the advantages of different active sites and behaved a dual-ion storage mechanism. Benefitting from the in-situ polymerization process, TAC with tube-type core-shell structure exhibited enhanced electron transport and improved utilization of active sites, resulting in high capacity (193 mAh g-1), outstanding rate performance (fast charging within 17 s), long-term stability (a high capacity retention of 87% after 1000 cycles) and high mass loading (10 mg cm-2). Additionally, TAC can well adapt to the temperature change, outputting a capacity of 72 mAh g-1 at -60 °C and 165 mAh g-1 at 80 °C. Such versatile polymer structure inspires the design of high performance organic materials for rechargeable batteries to satisfy high stability and wide temperature operations.