The Establishment And Simulation Of The Initial Discharge Specific Capacity Model Of Porous Carbon-lithium-sulfur Batteries

In the field of energy storage,lithium sulfur battery has become one of the most potential energy storage devices due to its high theoretical specific capacity(1675m Ah.g-1)and theoretical energy density(2600Wh.kg-1).However,the low conductivity of elemental sulfur and sulfide,the large volume change of sulfur removal/immobilization in the reaction process,and the "shuttle effect" of lithium polysulfide have seriously affected the commercialization process of lithium sulfur batteries.At present,due to its excellent sulfur carrying and sulfur fixation performance,as well as its ability to make up for the problem of fast capacity decay rate caused by the low conductivity of sulfur,nano porous carbon structure materials have become the research focus of lithium sulfur battery anode and diaphragm.In this paper,based on the research of porous carbon lithium sulfur batteries,obtaining a large number of relevant experimental data,through the literature and sums up the initial discharge specific capacity of porous carbon lithium sulfur batteries have a certain influence factors,using the statistical method and neural network,the mathematical model established between each other,and the mathematical model for simulation,porous carbon lithium sulfur batteries for experimental study provides certain theoretical guidance.The main research contents are as follows:In the first chapter,based on the current development situation of porous carbon lithium sulfur battery,the problems to be solved in this paper are proposed,the purpose and significance of the research are clarified,and the research methods and directions at home and abroad are sorted out.Finally,the research content and research ideas of this paper are clarified.In the second chapter,kruskal-wallis test method is mainly used to test and screen all the influencing factors and their cross terms of the initial discharge specific capacity.The inspection standard is P(28)05.0.Finally,the factors that have significant influence on the initial discharge specific capacity are screened out.In the third chapter,the significant influencing factors are analyzed and fitted by multiple additive regression.The statistical mathematical model of initial discharge specific capacity and its significant influencing factors was established.The average absolute error predicted by the simulation was 11.02%.The results show that the multiple additive regression model can better fit the relationship between dependentvariables and independent variables.It is compared with this model by taking multiple nonlinearity as the representative.The advantages and disadvantages of traditional statistical model and multiple additive regression model are analyzed.This will provide some theoretical guidance for the design of porous carbon physical structure parameters and test conditions.The fourth chapter,in order to test the accuracy of multivariate additive regression model.In this chapter,RBF network and GRNN network are used to establish the mathematical model between the initial discharge specific capacity and the influencing factors of its significance.The average absolute margin of error was11.52% and 10.44%,respectively.Compared with 11.02% of the multivariate additive regression model.The prediction results of the three models differ little,which verifies the reliability of the multiple addition regression model.The fifth chapter,mainly based on multivariate additive regression model for the simulation.In order to get the simulation results more close to the reality,the constraint conditions and simulation data were firstly constructed,and then the model simulation was carried out.According to the standard that the larger the initial discharge capacity is,the better,50 sets of optimal simulation experimental data are obtained,which can be used as reference for relevant experiments of porous carbon lithium sulfur battery.The sixth chapter,all for this article research results are summarized,and based on some research achievements and shortcomings,this paper for the next step are discussed and prospects of research work.