Enable Dendrite-Free Lithium Anodes in High Energy Batteries for Electric Vehicles

Rechargeable lithium-ion batteries with low cost ($100/kWh) and high energy density (500 Wh/kg) are critically desired to meet the ever-increasing needs for energy. One way to achieve the goals is to enable lithium metal as the anode for lithium-ion batteries owing to its ultrahigh theoretical capacity (3,860 mAh/g) and the high negative potential (-3.04 V vs. standard hydrogen electrode). However, the problems of lithium dendrite formation and low Coulombic efficiency (CE) during electrochemical cycling prevent the wide deployment of lithium anodes. In order to tackle the two problems of lithium anodes, researchers have pursued a number of strategies including electrolyte additives, solid polymer electrolyte and different coatings acted as artificial solid electrolyte interphase (SEI) layers. Making artificial SEI layers is a most promising and effective strategy to enable the use of lithium anodes. In the proposal, ultrathin lithium will be used and advanced coatings will be prepared with excellent properties, including great mechanical strength, high dielectric constant and high lithium-ion conductivity, to greatly suppress lithium dendrites and stabilize the interface of the lithium/electrolyte for ultrahigh CE. In Phase I, different advanced coatings will be directly prepared onto the ultrathin lithium metal. Such protected Li will be assessed in lithium-ion batteries and lithium-sulfur batteries (coin cells and pouch cells) at practical current rates for 300-400 cycles. Scanning electron microscope (SEM) images for the cycled anodes will be taken to check if there is any dendrite formation.