Conductive halloysite nanotubes/polypyrrole cathodes prepared by one-step in situ polymerization for zinc-ion batteries

Zinc-ion batteries (ZIBs) are desirable as one of the most potential energy storage devices owing to the environmental friendliness and abundant zinc reserves. Nevertheless, numerous promising cathode materials suffer from complicated preparation processes and low electronic conductivity. Herein, a high-performance cathode material (HNTs-PPy) for ZIBs based on halloysite nanotubes (HNTs) with a polypyrrole (PPy) coating is prepared through an efficient one-step in situ polymerization. The PPy nanoparticles can be uniformly and densely coated on the external surface of HNTs with a thickness of ~ 3.8 nm. The surface valence state and banding configuration of HNTs-PPy show the diffusion of the electron cloud from the outside of the PPy to the inside of HNTs and further form a strong polycomplexation between HNTs and PPy. Compared to PPy, introducing HNTs efficiently increases the contact area between the electrolyte and the composite cathode materials and sequentially enhances the cycling stability. The ZIBs based on HNTs-PPy cathode also achieve a capacity retention of 87.4% at a current density of 0.5 A g −1 after 500 cycles. This work develops a new perspective strategy for large-scale production of time- and cost-efficient cathode materials for aqueous batteries.