Electrochemical performance of lignin doped SDC as anode for application in low temperature solid oxide fuel cell

Lignin is the second most abundant biopolymer on earth, constituting 30% of the dry weight of softwood and 20% of hardwood. In this study, lignosulfonate, is used as fuel in the solid oxide fuel cell to produce a power and heat, which is a byproducts from the wood pulp using sulfite pulping. To enhance the performance and conductivity of the biomass based fuel cell, the lignin was treated with hydroxides (Li/K) and chlorides (Fe2Cl3) at different temperature 200-500 °C. Single cell performances were evaluated by I-V measurements, and when 50 wt. % lignin was introduced into the SDC by ball-milling, the 50 wt.% lignin- SDC anode material could achieve the highest power density of up to 45 mW cm-2. The corresponding power density was up to 130m W cm-2 when 50 wt.% lignin-SDC have similar performance. It has been concluded that a direct lignin fuel cell is feasible and the lignin hydrophilicity is critical for the cell performance. And the calculated electrical efficiency of the cell was about 30%. It has been found that the open circuit voltage (OCV) of the DCFC could reach around 0.8 V in most of the trials. The pH adjustment not only increased the maximum current density but also reduced the differences between the two types of lignins, resulting in an OCV of 0.7-0.8 V. It has been concluded that a direct lignin fuel cell is feasible and the lignin hydrophilicity is critical for the cell performance.