基于Ag/AgCl海洋电场探测电极粉体优化制备及电性能的探究

Study on Optimal Preparation and Electrical Properties of Ag/AgCl Marine Electric Field Detecting Electrode Powder

为探究前驱粉体对Ag/AgCl电极电化学性能的影响,利用固相球磨法加入表面活性剂以及不同的干燥方法制备AgCl粉体,寻找出优化制备工艺,并制备了Ag/AgCl多孔电极。利用SEM、XRD对粉体进行微观结构分析表征,利用eDAQ电化学工作站和低噪声前置放大器噪声测试装置对电极进行电化学性能测试,讨论微观结构对电极的极化性能、短期稳定性以及电化学噪声水平的影响,并测试其外加电场响应性能。结果表明,固相球磨中加入CTAC(十六烷基三甲基氯化铵)球磨4 h并利用冷冻干燥法所制备的AgCl粉体分散性好,形貌均一,粒径1μm以下;所制备的复合Ag/AgCl电极结构呈多孔状,开孔率约32.78%;电极的交换电流密度大,约1.0035 A·cm^-2,不易极化;两电极一致性好,极差电位小,约为0.005 mV;电极具有优良的短期稳定性,电极电势波动不超过0.01 mV/24 h,在1 Hz频率处功率谱密度可低至1.02 nV/√Hz,为水下微弱电场探测提供了极为有利的测试基础。

In order to investigate the effect of precursor powders on the electrochemical performance of Ag/AgCl electrodes,AgCl powder was prepared by adding surfactant and different drying methods using solid-phase ball milling method.An optimized preparation process was found,and Ag/AgCl porous electrode was prepared.The microstructure of the powder was analyzed and characterized by SEM and XRD;the electrochemical performance of the electrode was tested by the eDAQ electrochemical workstation and low-noise preamp noise test device to test,and the effect of microstructure on the polarization performance,short-term stability and electrochemical noise level of the electrode were discussed,and its external electric field response performance was tested.The results show that AgCl powder prepared by freeze-drying method with CTAC(cetyltrimethylammonium chloride)ball mill added to solid phase mill for 4 h has good dispersibility,uniform morphology and particle size below 1μm;The prepared composite Ag/AgCl electrode has a porous structure with an open porosity of about 32.78%;the electrode has a large exchange current density of about 1.0035 A·cm^-2,which is not easily polarized;the two electrodes have good consistency and a small potential difference about 0.005 mV;the electrode has excellent short-term stability,the electrode potential fluctuation does not exceed 0.01 mV/24 h,and the power spectral density can be as low as 1.02 nV/√Hz at 1 Hz frequency,which provides an extremely favorable test basis for underwater weak electric field detection.