Abstract
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•3D multifunctional electrode was developed for energy production & storage.•Facile & cost-effective drying technique was developed for carbon foam production.•N-doped carbon foam possesses a unique combination of macro, meso, and micropores.•MFC operated with N-doped carbon foams produced very high power density, 36Wm−3.•High charge storage capacity and Li-battery-comparable energy density was obtained.
This paper reports the synthesis of N-doped carbon foams (NCFs) using simple, environment-friendly, and self-developed freezing method. A robust structure of NCFs along with high surface area, hierarchical pore structure, and nitrogen/oxygen functionalities allows their application as free-standing electrode. Microbial fuel cell equipped with differently prepared NCFs as free-standing anode and metal-free cathode generates significantly higher power density, 35.74Wm−3 than conventional electrodes. Furthermore, NCF with an optimized resorcinol-formaldehyde content shows significantly high-charge storage capacity, 799Fg−1, at 0.25Ag−1 and also delivers a high energy density, 111Whkg−1, equivalent to that of a Li-ion battery.