Size Effect Of Micro-patterned Lithium Metal Anode On Electro-plating And Stripping In Non-aqueous Lithium Metal Batteries

Lithium has considerable application prospects on lithium batteries for its extremely high specific capacity(ca.3860mAh/g,2060mAh/cm3)and the lowest electrode potential(-3.045V vs.standard hydrogen electrode).The safety prob-lem caused by the uncontrollable lithium dendrite,large volume expansion and poor cycling performance has troubled researchers for several decades.Metallic lithium batteries have been paid much more attention recently due to the Li-air,Li-S and solid state batteries booming.Researchers made numerous attempts such as adding additives in electrolyte,constructing three dimensional structures on the current collector,applying mechanical compressive stress on the solid state/polymer battery systems,giving a surface treatment,employing lithium alloy or using high concentration salt electrolyte to improve its security level and to lengthen its life.It's reasonable to expect that there would emerge attractive application prospection on second lithium metal battery.We studied the effect of electric field distribution under the electrostatic balance condition on isolated conductor surface which could be a reference to illustrate the dynamics of lithium ion's plating and stripping in the non-aqueous electrolyte.In order to improve property of the lithium metal anode,we propose a scaling up method fabricating orderly structured holes/cylinders on lithium anode.Firstly,we got the three hexagonal holes patterned lithium metal anode by the micro-fabrication method.The three samples' diameter is 500nm,5um and 50um respectively.Using the samples,we assemble the CR2032 and three electrode cells with different electrolytes respectively.After electrochemical tests,we disassemble the cell and washing the patterned lithium metal anode,and analyzing the morphology evolution by Scanning Electronic Microscope(SEM).Regulated by the micro-electric field,partial lithium ion deposited on the side of the patterned holes as it has the largest electric filed.Besides,the pattern increases the specific area.A lower real electrode current density resulting from a large specific surface area leads to a longer "Sand's Time",which suppresses the formation of lithium dendrite.5um pattern holes has the lowest over-potential by comparing different pattern lithium metal battery and we also give a quasi-quantitative analysis of the hole deposition in the 5um pattern stress-free lithium metal battery.