A “two cooking with one fish” strategy for modulating both polyaniline cathode and zinc anode towards enhanced kinetics and cycling stability for aqueous zinc ion batteries

Abstract

The adverse stability of both polyaniline (PANI) and Zn anode remains a challenge to the long−term cyclability and rate capability of aqueous Zn−PANI batteries. Herein, a “two–cooking with one fish” strategy is presented to modulate both PANI cathode and Zn anode, in which nanoscale graphene sheets in cathode can promote ordered growth of PANI array, being conducive to provide large electrochemical active area and efficient transport pathways and alleviate volume variation during repeated charging/discharging process. Meanwhile, the honeycomb–like structure of graphene sheets as protective layer can accelerate zinc ion transport kinetics and suppress side reactions and zinc dendrite growth. Consequently, the optimized G/Zn symmetric cell delivers a remarkable lifespan over 1000 h at 1 mA cm−2 with 1 mAh cm−2. Furthermore, the assembled PANI/G/CC||G/Zn battery could deliver a specific capacity of 265.8 mAh g−1 at 0.2 A g−1, excellent rate capability (145.5 mAh g−1 at 20 A g−1), a maximum energy density of 246.9 W h kg−1 and power density of 8675.9 W kg−1, and especially capacity retention of 91.1 % after 10000 cycles. Combining with additional merits of low cost, eco–friendliness, and safe operation, our design will shed light on resolving the issues on cyclability and rate capability of aqueous Zn−PANI batteries.