In situ firmly anchored polypyrrole on NiV-LDHs for efficient aqueous-system asymmetric supercapacitors

Abstract

Polypyrrole (PPY) and nickel-based polyvalent hydrotalcite (NiV-LDHs) electrode materials have been extensively investigated and studied in the field of supercapacitor electrodes. The poor conductivity and stability of nickel-based hydrotalcite are deemed unsatisfactory, thus prompting the exploration of in situ introduction of conductive polymers to enhance its stability and conductivity. The hydrothermal synthesis of NiV-LDHs was utilized for the in situ growth of a specific quantity of polypyrrole, resulting in the formation of PPY@NiV-LDHs-3. PPY@NiV-LDHs-3 exhibits superior performance in terms of cycle stability, rate capability, and mass-specific capacitance compared to both PPY@NiV-LDHs-X (X = 1 and 6) and NiV-LDHs. Furthermore, the self-assembled PPY@NiV-LDHs-3//AC ASC showed relatively excellent energy density (70 W h kg⁻¹) at a certain power density (2084 W kg⁻¹). Satisfyingly, the specific capacitance of PPY@NiV-LDHs-3//AC ASC holds up well (62.50%) after 10 000 cycles at a current density of 10 A g⁻¹. PPY@NiV-LDHs-3 obtained by the structural design is a breakthrough and successful concept in exploring the development of high-performance supercapacitors.