Continuous conversion of biomass wastes in a La0.75Sr0.25Cr0.5Mn0.5O3–δ based carbon–air battery

•Falling leaves can be converted into electricity via a carbon-air battery.•The battery exhibits the maximum power density of 330 mW cm−2.•The performance is stable over 1000 min without degradation.•A robust material LSCM instead of Ni is used as the anode.•Nano-scale design is applied to increase anode performance.

In this study, a carbon–air battery based on a solid oxide fuel cell (SOFC) is demonstrated to continuously generate electric power through a direct oxidation of the biomass wastes. Due to inevitable poisoning gases such as H2S, SO2, CO2 in wastes, more stable La0.75Sr0.25Cr0.5Mn0.5O3–δ (LSCM) instead of Ni is used as the anode material for SOFC. Nano– and/or micro–particles of LSCM are prepared onto a 3D porous yttria–stabilized zirconia (YSZ) scaffold via an infiltration process, in which YSZ backbone provides rich pathways for O2− which can remedy the major defect of the LSCM, negligible O2− conductivity, and thus expanding the triple–phase boundary (TPB) to the whole anode. When falling leaves are tucked into the anode chamber, an attractive performance of 330 mW cm−2 can be reached for the battery at 800 °C, which is among the best in the published open literature. There is no visible degradation in cell performance during stability-test for 1000 min. This work provides a novel waste fed SOFC system that has a wide range of application potentials due to its unique advantages of low cost, low emission and high efficiency.