Graphene nanoribbons: High-quality conductive additive for high performance aqueous zinc-ion batteries

As an important part of the cathode of aqueous zinc -ion batteries (ZIBs), conductive additive plays an important role in its electrochemical performance. Herein, we initiate graphene nanoribbons (GNRs) as a novel conductive additive for ZIBs, and find that GNRs have satisfactory compatibility with different cathode materials and can form a unique "face-to-face" continuous conductive network within the electrode, thus achieve better comprehensive improvement effect on electrodes' electronic/ionic conductivity compared with traditional carbon black, and significantly improve the rate capability together with cycle stability. To be specific, the GNRs conductive additive successfully increased the specific discharge capacity of ZnxV2O5 from 389.5 mAh g-1 of acetylene black (365.1 mAh g-1 of ketjen black, 377.1 mAh g-1 of super P) to 487.0 mAh g-1 at 0.1 A g-1, and boosted the capacity retention rate from 66.8 % to 104.6 % after 5000 cycles at 5 A g-1. The effect of different amount of GNRs on the electrochemical properties of the cathode is also systematically explored. In addition, the specific discharge capacity of alpha-MnO2 is also enhanced by about 122 % at 0.1 A g-1. Therefore, the application of GNRs as a novel conductive additive for ZIBs provides an extremely promising path for the development of highperformance ZIBs.