Construction And Application For The Association Model Of The Influene Of Sulfolane On Film-forming Process Of LiBOB Based Electrolyte

With the increasing demand for energy,high-performance lithium-ion batteries,as an ideal energy conversion device,have become a research hotspot in the current energy field.As an important part of the lithium ion battery,electrolyte determines its working voltage and safety performance.Therefore,developing an electrolyte system with excellent performance is an important path to improve the battery performance.Existing studies have shown that when the SEI layer contains the number of sulfurcontaining components,the lithium ion conductivity and thermodynamic stability of the interface film will be significantly improved.Therefore,it is of great practical significance to fully understand the reaction mechanism of the sulfur-containing solvent in the battery process to solve the above problems.In the previous study,a new high-voltage electrolyte system with 1 mol/L Li BOB DMC/GBL/SL(1:1:1,volume ratio)was developed and found that this system has good compatibility with MCMB electrodes.At the same time,it was found that the existence of sulfolane in the layer has a great influence on the performance of the electrolyte,and accordingly affects the performance of the negative electrode half-cell.On the basis of this discovery,this study was absorbed in the effect mechanism of SL on the properties of electrolyte and battery.firstly,based on the basic battery performance test,the voltage at the place where the main reactant reacts markedly is set as the electrode reaction node,and the complex electrode process is divided into several simple stages to study.By tracking the study of the reaction process of sulfolane at the electrode interface,the influence of the introduction of sulfolane on the film formation and film properties of the boron-based lithium salt reaction,and the influence of the film properties on the battery performance,the charge and discharge process was revealed from two aspects of composition and morphology.The specific course of the formation of the interfacial film reveals the influence of various components in the electrolyte,in particular sulfolane,on the film formation process and the influencing mechanism.In addition,based on the results of the above studies,the influence of sulfolane on the pre-filming process of the battery is analyzed due to the force of the electric field.It is considered that sulfolane has a high polarity,and therefore,it will accumulate on the surface of the electrode under the action of the electric field force to form an electric double layer structure,resulting in an increase in the amount of sulfolane on the surface of the near electrode,and thus the concentration of Li BOB in this region is low.The concentration in the electrolyte in which no sulfolane was added at the same position reduced the number of reactants,weakened the reaction intensity,and inhibited the excessive decomposition of Li BOB.