The Development of New Type of Carbon Dioxide Gas Sensor Based on Lithium Conductor

基于锂导体的新型二氧化碳气体传感器的研制

基本信息

批准号：
02555163
负责人：
ADACHI Gin-ya
金额：
$ 8.51万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

The object of this research is to develop a portable carbon dioxide gas sensor by using a solid electrolyte based on lithium ionic conductor. The electromotive force (EMF) measurements were carried out with several CO_2 gas concentrations. The sensor was set up by using LiTi_2 (PO_4)_3+0.2Li_3PO_4 sintered material as the solid electrolyte, Li_2CO_3 as the detecting electrode, and CaCO_3 as the reference electrode. The measured EMF was in good agreement with the calculated EMF for the gas content from 80 ppm to 1 %. The response time was within several minutes.In a practical application, this type of sensor is expected to be installed in exhaust gas atmosphere. The influence of several gases coexistence with carbon dioxide was investigated. No influence was observed with NO_2 gas copresence from 100 ppm to 450 ppm. This is beca. Mse that lithium nitrate decomposes at the operating temperature of 650ﾟC. The EMF value becomes lower than the calculated EMF even at the SO_2 gas content of 20 ppm. This is ascribed to the formation of lithium sulfate on the electrolyte surface.One another gas should be investigated is water vapor. The sensor can detect the C0_2 concentration from 1000 ppm to 1 % at the water vapor concentration of 0-220g/m^3. The EMF output decreses in the CO_2 gas content lower than 1000 ppm. This phenomenon occurs by the chemical reaction between water vapor and lithium carbonate. In order to lower the operating temperature from 650ﾟC, several electrodes were selected as candidates. The sensor can detect the CO_2 gas concentration from 100 ppm. to 1 % at 350ﾟC in the case that Li_2CO_3-K_2CO_3-Na_2CO_3 eutectic mature was applied as the electrode.

这项研究的目的是通过使用基于锂离子导体的固体电解质来开发便携式二氧化碳气体传感器。用几个CO_2气体浓度进行电动力（EMF）测量。通过使用LITI_2（PO_4）_3+0.2LI_3PO_4用作固体电解质，LI_2CO_3作为检测电极，将传感器设置为caco_3作为参考电极。测量的EMF EMF的气体含量从80 ppm到1％。响应时间在几分钟之内。在实际应用中，这种类型的传感器预计将安装在废气气氛中。研究了与二氧化碳共存的几种气体的影响。 NO_2气体相处从100 ppm到450 ppm，没有观察到任何影响。这就是Beca。 MSE，硝酸锂在650°C的工作温度下分解。即使在20 ppm的SO_2气体含量下，EMF值也会低于计算出的EMF。这分配给了电解质表面上硫酸锂的形成。应该研究一种气体是水蒸气。传感器可以在0-220g/m^3的水蒸气浓度下检测到C0_2浓度从1000 ppm到1％。 EMF输出的CO_2气体含量下降低于1000 ppm。这种现象是由于水蒸气和碳酸锂之间的化学反应而发生的。为了将工作温度从650°C降低，选择了几个电极作为候选。传感器可以从100 ppm检测CO_2气体浓度。如果将Li_2CO_3-K_2CO_3-NA_2CO_3共晶成熟作为电极，则在350 ﾟC处达到1％。