孔隙率对传感器多孔电极材料导电性能的影响  

Effect of Porosity on the Electrical Conductivity of Porous Electrode Materials for Sensors

作　　者：高君华 黄浩[1] 曾冲 郑瑞伦[1] GAO Junhua;HUANG Hao;ZENG Chong;ZHENG Ruilun(School of Electronic Information and Electrical Engineering,Chongqing University of Arts and Sciences,Engineering Research Center of New Energy Storage Devices and Applications,Chongqing 402160,China;School of Electronic Engineering,Heilongjiang University,Harbin 150080,China)

机构地区：[1]重庆文理学院电子信息与电气工程学院,重庆市高校新型储能器件及应用工程研究中心,重庆402160 [2]黑龙江大学电子工程学院,哈尔滨150080

出　　处：《材料导报》2021年第18期18018-18023,共6页Materials Reports

基　　金：重庆市自然科学基金面上项目(cstc2020jcyj-msxmX0920);重庆市教委科技项目(KJQN202101304);永川区自然科学基金项目(2021yc-jckx20045)。

摘　　要：电极材料是保证氧传感器性能的关键。电极材料的多孔性和突出的原子振动非简谐效应对其导电性有重要的影响。为了提高电极材料的导电性能,本工作考虑到原子的非简谐振动,应用固体物理理论和方法,研究了氧传感器多孔电极材料电导率及其热稳定性随温度、时间、颗粒半径的变化规律,并探讨了原子非简谐振动和孔隙率的影响。结果表明:多孔Pt电极材料的电导率小于块状电极材料的电导率,且颗粒愈小,两者的差愈大;多孔Pt电极材料的电导率及其热稳定性系数均随温度的升高而非线性减小,当温度T<300 K时,减幅较大,当温度T>1000 K时,则减幅极小并趋于常量。电导率随时间延长而减小,但减幅极小;电导率随颗粒半径的增大非线性增大。孔隙率对电极材料的电导率有影响:颗粒愈小,孔隙率愈大。电极材料的电导率愈小,颗粒的体内与表面层的电导率的差愈大。考虑到原子振动的非简谐效应,电极材料的电导率大于简谐近似时的结果,且温度愈高,非简谐与简谐近似下的差值愈大,即非简谐效应愈显著。The electrode material is the key to ensuring the performance of the oxygen sensor.The porosity of the electrode material and the prominent anharmonic effect of atomic vibration have an important influence on its conductivity.In order to improve the electrical conductivity of electrode materials,this paper takes into account the anharmonic vibration of atoms and applies solid-state physics theories and methods to study the changes in electrical conductivity and thermal stability of porous electrode materials for oxygen sensors with temperature,time and particle radius,and the influence of atomic anharmonic vibration and porosity is discussed.The results show that the conductivity of Pt porous electrode materials is smaller than that of bulk electrode material,and the smaller the particles,the greater the difference between the two.The conductivity and thermal stability coefficient of porous Pt electrode material decrease nonlinearly with increasing temperature.When the temperature T<300 K,the change is significant,while when the temperature T>1000 K,the change is very small and tends to be constant.The conductivity decreases with increasing time,but the change is minimal.While the changing rate of conductivity increases non-linearly with increasing particle radius.Porosity has an effect on the conductivity of the electrode material:the smaller the particle,the greater the porosity,the smaller the conductivity of the electrode material,and the greater the difference between the conductivity in the body and the surface layer of the particle.When the anharmonicity of atomic vibrations is taken into account,the conductivity of the electrode material is greater than the result of the simple harmonic approximation,and the higher the temperature,the greater the difference between the anharmonic and simple harmonic approximation,i.e.,the more significant the anharmonic effect.

关 键 词：传感器多孔电极材料 电导率 热稳定性 孔隙率 非简谐效应 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]