초록 |
Li-metal batteries (LMBs) have been revisited to exceed the energy density limit of today’s Li-ion batteries. However, the use of Li-metal anode has long been plagued due to Li dendrite growth and poor Coulombic efficiency (CE). Moreover, Li anode suffers from uncontrolled evolution of interphase structures upon cycling and severe Li pulverization, resulting in cell failure. In this talk, practical ways for interface engineering from Li-electrolyte microstructure to cell-level design will be presented. Furthermore, a prototypical 300 Wh/kg Li-metal pouch cell (1.0 Ah) has been successfully demonstrated to reveal more realistic challenges. A vital issue inherent to Li-metal pouch cells is excessive cell swelling due to parasitic reactions with electrolytes and highly porous structure buildup. Through localized high-concentration electrolyte and uniform external pressure, the cell swelling can be suppressed up to 100%, resulting in more than 200 stable cycles (86% capacity retention). |