Dendrite-Suppressed Lithium Plating from a Liquid Electrolyte via Wetting of Li3N

摘要

Lithium metal is an ultimate anode material to provide the highest energy density for a given cathode by providing a higher capacity and cell voltage. However, lithium is not used as the anode in commercial lithium-ion batteries because electrochemical dendrite formation and growth during charge can induce a cell short circuit that ignites the flammable liquid electrolyte. Plating of lithium through a bed of Li-3 N particles is shown to transform dendrite growth into a 3D lithium network formed by wetting the particle surfaces; plating through a Li3N particle is without dendrite nucleation. The Li3N particles create a higher overpotential during Li deposition than that with dendrite growth in galvanostatic charge/discharge tests. The characteristic overpotential increase is correlated with the morphological changes and a more isotropic growth behavior. The Li3N-modified Li electrode shows a stable cycling performance at 0.5 and 1.0 mA cm(-2) for more than 100 cycles. The origin of the bonding responsible for wetting of the Li3N particles by lithium and for plating through a Li3N particle is discussed.