Studies On Electrochemical Performance Of High Power Density Lithium-Silver Battery

Batteries, as energy capacity devices, people have always been making great efforts tomake them deliver higher energy desity, more power density and perform more safety.Today, rocking-chair lithium ion batteries, widely valued and used in the world, areencounterring bottleneck in performance promotion. Therefore, it’s very necessary toexplorer new materials or new structures to meet the demond. In this paper, the two newtypes of lithium silver batteries—dual-electrolyte lithium silver battery and organicelectrolyte lithium silver battery, both can deliver higher energy density and more powerdensity than traditional lithium ion batteries.As the dual-electrolyte lithium silver battery, we need first to find out a kind of organicelectrolyte, which is hydrophobic, excellent electric conducted and chemical stable againstalkaline. We detected the electrical conductivity of several electrolytes, made up of1MLiClO4, PC, DMC or DEC, by AC impedence method, and then selected the1M LiClO4PC/DMC, the highest electrical conductivity electrolyte, as the organic electrolyte of thedual-electrolyte lithium silver battery.Next, we used the cyclic voltammetry and chronopotentiometry to research theelectrochemical performance of the positive electrode, mainly including its tolerance toOH^-, Li⁺, ClO₄^-and its exchange current density. The results indicated that the redoxproducts of the positive electrode are almost not be influenced with the increase of OH^-, butthe redox potential would be changed a little, as well as Li⁺, ClO₄^-. The tafel plot shows, theexchange current density of the positive electrode is10mA/cm², which combined with thenegative electrode, can provide beneficial factors for the high power density of thedual-electrolyte lithium silver battery.This paper also studied the electrochemical impedance characteristics and chemicalstability of Celgard separator. The related results showed that, worthy, the area-specifcimpedance （ASI） of the wetted Celgard is signifcantly smaller than the ASI of theLISICON plate （449.6Ω/cm²）. The low ASI of Celgard makes certain degree ofcontributions to the high power density of the dual-electrolyte lithium silver battery. Andboth the infrared spectroscopy （IR） and scanning electron microscopy （SEM） resultsshowed that, Celgard is chemical stable enough to be used in the dual-electrolyte lithiumsilver battery. A serious charge-discharge test of the dual-electrolyte lithium silver battery were takenby Land, and the battery did deliver high energy density of650Wh/kg and power density915W/kg, which are both higher than traditional zinc silver batteries and lithium ionbatteries. However, due to the water molecules diffusion, the cyclic performance of thedual-electrolyte lithium silver battery is not very well.The relevant research on the organic lithium silver battery is a beneficial explorer. Theexperimental methods are similar to the dual-electrolyte lithium silver battery: from thethree electrodes research to the whole battery research. And both of them showed thesimilar results: great power density and poor cyclic performance. The capacity reached300mAh/g, had two discharge plateau, which is similar to zinc silver batteries.At the end of the paper, we have summarized the merits and defects of the two lithiumsilver batteries, pointed out the probably research directions and improvement ways. Wethink that, the two batteries could be widely applied in aerospace, aviation and militaryfields as activated batteries, and if the cyclic performance were improved, they would havea more prosperous future.