Research And Implementation On The Voltammetry Testing Technology Of Electrochemical Workstation

Electrochemical testing and analysis method plays an important role in the study of the metal corrosion and battery parameters detection. However the existing test and analysis instrument in electrochemical test and analysis is far from comprehensive, relatively poor selectivity. In this paper, based on the research of the above problem, relying on the "973" project corpus “Battery safety testing technology research”, voltammetry testing technology of the electrochemical test has been studied, designing a set of software testing and analyzing system, realizing various test methods and completing the analysis of the data processing to extract the parameters in the electrochemical reaction. The main contents are:1. For extracting the corrosion current of metal and electrochemical parameters in the process of corrosion, analyzing the steady-state polarization curves of corroding metal was adopted. At the same time, three methods are used: Tafel linear extrapolation method, polarization curves equation was transformed to Tafel equation, through calculating the logarithm in the strong polarization area. Weak polarization region nonlinear fitting method: polarization curves equation was rewritten. Then parameters were extracted by nonlinear least square method. Linear polarization method: because of small polarization voltage, polarization curves equation could be in accordance with the series expansion and then polarization curves can be approximated by a straight line by ignored higher order terms.2. For in the transient process different test conditions having different response, by controlling various different test conditions, different electrochemical voltammetry methods is formed, being divided into the control current method and the control voltage method which to be testing and adopting to extracting electrochemical parameter. According to the electrochemical control system and the spread control system as different electrochemical substance delivery process in the reaction process of the two methods, equivalent circuit method and the diffusion equation method were adopted to extracting electrochemical parameter. For the electrochemical control system, the electrochemical model was extracted as equivalent circuit. The parameters of equivalent circuit were extracted by nonlinear least square method, combined response function and response curve of different incentives. According to the spread control system, getting the response function of the electrode potential through the diffusion equation method, the electrochemical parameters were extracted by nonlinear least square method. According universal reversible wave equation, reversible feature system was judged by orthogonal polynomials.Calculating the corrosion parameters by Tafel analysis in the analysis of metal corrosion have been mainly used in the existing test and analysis platform, which has great limitation since it requires a wide range of data. This paper used three analytical methods by which users can select appropriate data segment to analyze the user can select the appropriate data segment to analyze and accurately calculate the corrosion parameters according to the user needs. In the transient, the different test methods is applied to comprehensively analysis the equivalent circuit model parameters from the time domain. Based on the research of voltammetry testing technology, its function has been integrated into an electrochemical software system. Combined with hardware and software platform, all kinds of voltammetry methods have been comprehensivly tested and analyzed. The test results are accurate, reliable and meet the design requirements.