Development of a tubular direct carbon solid oxide fuel cell stack based on lanthanum gallate electrolyte

The direct carbon solid oxide fuel cell (DC-SOFC) is a new-type energy conversion device that converts chemical energy stored in solid carbon into electricity efficiently with environmental benignity and low cost for abundant carbon resources, which reveals upward impetus recently. To accelerate the practical application of DC-SOFC, here, we report a high-performance La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) electrolyte-supported tubular DC-SOFC stack for portable applications, in which Ag- Ce0.8Gd0.2O1.9 (Ag-GDC) is used as symmetrical electrodes and camellia oleifera shell char as fuel. The performance of the 3-cell-stack stands out, with an open circuit voltage (OCV) of 3.18 V, an output power of 2.65 W, and a maximum volumetric power density of 605 mW cm-3 at 800 degrees C. In addition, the stack can survive for 5.82 and 1.12 h under the constant discharging currents of 200 and 800 mA, respectively, exhibiting discharge capacities of 3492 and 2688 mA h. Furthermore, adopting the external anode design can sextuple the fuel load and lead to remarkably improved output performance, discharge time, and discharge capacity of the stack (3.71 W, 9.2 h, 22080 mA h). The above results indicate that LSGM electrolyte-supported tubular DC-SOFC stacks show great potential for developing into high-performing, efficient, and environmentally friendly portable power sources for distributed applications.