Engineering 1D chain-like architecture with conducting polymer towards ultra-fast and high-capacity energy storage by reinforced pseudo-capacitance

Abstract

Compared to other energy storage types, capacitive energy-storage serves increasingly significant roles in shortening reversible cycling times and enlarging high power than traditional batteries. It still suffers from the low pseudo-capacitive level and short of electrodes, along with low energy density. Considering the great theoretical capacity, here 1D chain-like Co3O4 is prepared though the thermal oxidation of the self-assembled rod-like Co-precursor. Followed by in-situ polymerization of pyrrole monomer, the Co3O4 were encapsulated in the transparent PPy shell. Particle size-tuning, 1D architecture-altering, conducting PPy introduction could effectively broaden the energy distribution of ions, increase the speed of ions directional transferring and improve the conductivity with protecting electrode materials. As Li-storage anodes, Co3O4/PPy delivers a stable capacity of 816.6 mAh g−1 at 1.0 A g−1 after 300 cycles. 801.3 mAh g−1 at 5.0 A g−1. The capacity of full-cell still delivers 526 mAh g−1 at 3.0 A g−1 after 50 loops. Supported by detailed kinetic analysis of CV curves, it is confirmed, (1) the nature of Co3O4 approaches to capacitor-like behavior; (2) its electrochemical properties are dominated by capacitive contributions with increased current density as well as cycling. This work provides an in-depth sight on Co3O4, and further improving its pseudo-capacitive behaviors.