Defect engineering tuning of MnO2 nanorods bifunctional cathode for flexible asymmetric supercapacitors and microbial fuel cells

Abstract

An effective surface and structural modulation strategy is developed to greatly boost the electron transfer rate, active sites as well as cycle stability of MnO2 nanorods by introducing native oxygen vacancies. Consequently, the as-prepared material exhibits exceptional performances as a dual function positive electrode for flexible asymmetric supercapacitors (ASCs) and microbial fuel cells (MFCs). Benefiting from its higher surface area, increased active sites and much better reaction kinetics, the maximum energy density of ASCs device reaches 56.04 Wh kg−1, and the highest power density is 1639 mW m−2 for the MFCs device. Most importantly, a self-powered system has been built by integrating the flexible ASCs and MFCs, which be able to achieve chemical energy conversion and energy storage.