INVESTIGATION OF COUNTER ELECTRODE MATERIAL FOR NASICON BASED POTENTIOMETRIC CO_2 SENSOR

摘要

Li_(0.4)CoO_2 was investigated for its applicability to a potentiometric CO_2 sensor using NASICON (Na~+ conductor, Na_3Zr_2Si_2PO_(12)) as a solid-reference counter electrode material. Compared with Na_(0.6)CoO_2, Li_(0.4)CoO_2 was more stable to storage at room temperature as well as to attack by CO_2 at 600℃, as measured for powders or powder attached devices. When coated with a layer of glass, Li_(0.4)CoO_2 attached-counter electrode allowed the device to generate stable EMF response to CO_2 at 450℃. These results confirm that Li_(0.4)CoO_2 can be used as a solid reference counter electrode even more reliable than Na_(0.6)CoO_2.