BACKGROUND The morphology and size of MnO2 that deposited on a carbon clothelectrode have dramatic effects on the electrochemical properties and cycling life. Currently, MnO2 and its composite structures with zero-dimensional (0D) nanospheres, one-dimension (1D) nanotubes and two-dimension (2D) nanomesh have been successfully synthesized and employed in MFC. Hence, the development of a three-dimensional (3D) flexible, cost-effective and high-performance anode is of great significance for microbial energy harvesting. RESULT Herein, we have fabricated 3D cauliflower-like polypyrrole@manganese dioxide (PPy@MnO2) composites, which are successfully grown on carbon cloth (CC) anode by electrodeposition to promote the power production and storage in microbial fuel cells (MFCs). Impressively, the as-prepared PPy@MnO2 modified CC anode delivers a power density of 2139.7 +/- 17.5 mW m(-2) and produces an areal capacitance of 1120 +/- 12.8 mF cm(-2), which is 3.58 and 4.84 folds higher than that with bare CC anode, benefiting from the unique cauliflower-like 3D architecture with increased active centers that host the bacteria for more efficient charge transfer. Electrochemical analyses indicate that the PPy@MnO2 modified CC electrode has excellent electrochemical activity, capacitive behavior and long-term cyclabilities with smooth surface morphology and high porosity. CONCLUSION These findings not only provide a facile electrodeposition strategy for PPy@MnO2 nanoflowers modified CC anode, but also demonstrates its potential for the production and storage of energy simultaneously in MFC application. (c) 2019 Society of Chemical Industry