Preparation Of A New Mixed Ionic Liquid Electrolyte And Its Effect On The Performance Of Dual Ion Battery

Currently,dual ion battery(DIB)has been widely studied as novel electrochemical energy storage devices because of their low cost,environmental friendliness and high operating voltage However,the wide application of these battery is limited by the decomposition of organic electrolytes at high operating voltages.The lack of an electrode material that allows high-capacity,long-life,and the phenomenon of self-discharge of the battery is difficult to apply to the actual situation,and thus cannot fully meet the market demand.Therefore,the current focus of scientists are to develop a new type of high-efficiency,low-cost and environmentally friendly new battery.However,in order to solve the above problems,it is necessary to break away from the traditional energy storage mode.In this paper,starting from the electrolyte of double-ion batteries,chlorine-containing additives were introduced to improve the electrolyte properties,so as to improve the electrochemical stability of the electrolyte,and thus improve the working voltage of the double ion battery.The main research contents and conclusions of this paper are as follows:(1)We use 1,2-dimethy 1-3-propylimidazolium chloride(DMPICl)and aluminum trichloride(AlCl3)as conventional ionic liquid electrolytes,and graphite rods are used as positive and negative electrodes to produce excellent electrochemical properties.A dual ion battery(DIB)is based on this electrolyte to find a new type of cation instead of DMPI+for the self-discharge phenomenon of the battenr.To explore the effect of different ratios of Urea and aluminum trichloride(AlCl3)on the dual ion battery.By changing the ratio of the electrolyte and the electrode material,the highest specific capacity of the battery is 100 mAh g-1,but after 40 cycles,the specific capacity is attenuated to 30-40 mAh g-1,indicating that Urea does not bring about a substantial improvement in the performance of the dual ion battery.(2)Adding several chlorine-containing additives 1-methyl-1-propyl-pyrrolidine chloride(P13Cl)and 1-methyl-1-butyl-piperidine chloride(based on the conventional electrolyte)PP14Cl),in the hope of improving the performance of the battery.The focus of this paper is on the measurement of viscosity,conductivity and battery charge and discharge of mixed ionic liquids containing additives to reveal the mechanism by which the cations provided by the electrolyte are intercalated/deintercalated into the graphite electrode.Finally,it was found through analysis of the data that the developed DIB containing the additive showed a higher discharge voltage platform(4.2-4.0 V and 3.6-3.1 V).reversible specific capacity is 75 mAh g-1 and the coulombic efficiency is 96%at a higher current density of 4.5 V and 180 mA g-1,And with a coulombic efficiency of 94%after more than 800 cycle cycles.Although the additive does not improve the electrochemical window of the electrolyte and inhibits the self-discharge of the battery,it provides the physical property of the ionic liquid electrolyte mixture that has not been reported.