Incorporating polyimide cathode materials into porous polyaniline xerogel to optimize the zinc-storage behavior

Polyimide is a kind of promising organic-based electrode material for zinc ion batteries (ZIBs), with the merits of resource sustainability, environmental friendliness and structural diversity. At present, however, the study on polyimide-based electrode for ZIBs is fairly few, and the limited conductivity and capacity are also needed to be overcome. Here, a polyimide cathode material denoted as PUI is synthesized by using perylene-3,4,9,10-tetracarboxylic dianhydride and urea, and the zinc-storage performance is comprehensively optimized by taking advantage of a 3-D porous polyaniline (PANI) xerogel carrier, for instance, the specific capacity of PUI/PANI composite is 72 % higher than that of PUI, and the rate performance and cycling stability are both improved as well. The analysis of electrochemical kinetics reveals that the 3-D porous PANI can facilitate fast electron/ion transportation and high capacitive contribution during discharging and charging. Moreover, the mechanism analysis demonstrates the synergistically enhanced zinc-storage capacity of CO (in PUI) and N (in PANI) in PUI/PANI. This work promotes the application potential of polyimide-based cathode materials, and also highlights the valuable role of porous conducting polymer (e.g., PANI) in constructing high-performance cathode materials for ZIBs.