The Research On Suppressed Lithium Dendrite Growth By Adding Quaternary Ammonium Salt

Metal secondary battery with high energy density will be the first choice for secondary battery in the future.During the battery charges and discharges,the lithium dendrite will be formed in the electrode,which will lead to the battery short circuit or even explosion.The influence of the electrolyte additives?TMOAPF₆,TEAPF₆,TPAPF₆ and TBAPF₆?and the method of electrodeposition on suppressed lithium dendrite growth have been investigated in this paper.It:is found that in LiBr/DMF electrolyte and LiBr/DMF-PC electrolyte,the surface morphology of lithium deposited becomes smooth with the elongation of cationic alkyl chain length of the quaternary ammonium salts.In PC solution containing lithium bromide,the pulse electrodeposition has been studied and the parameters have been optimized.It is found that the lithium film with best morphology can be deposited under the optimized duty ratio?0.5?.The long single pulse deposition time can decrease the resistance of SEI film,and lead to the rough of the surface morphology.Using pulse deposition can suppress dendrite when the pulse current density is no less than 2 mA/cm.