The cell uniformity and connection mode of solid oxide fuel cell (SOFC) are important factors affecting the overall performance of the stack. The uniformity of flat-chip cells in the SOFC stack is evaluated by methods such as linear sweep voltammetry and electrochemical impedance spectroscopy. Then, the comprehensive effect of cell uniformity and connection mode on the stack's output performance and the underlying electrochemical mechanism are investigated by combining with the method of distribution of relaxation times. Results indicate that the cell uniformity and connection mode jointly affect the stack performance, i.e., the cell uniformity affects the stack lifetime, while the connection mode affects the stack's output power. In a series mode, a low cell uniformity will cause the poor-performance cell to over-discharge, which may accelerate the deterioration of the stack performance. Compared with the series mode, the parallel mode will cause a higher power loss, which mainly comes from ohm resistance, oxygen exchange and charge transfer processes but affects the stack lifetime to a small degree. In general, the peak power of the series stack is high, but the lifetime is greatly affected when the cell uniformity is low. The power loss of the parallel stack is obvious, but the influence on the stack lifetime is weak.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |