Porous scaffold of TiO2 for dendrite-free lithium metal anode

Lithium metal anode is of great interest for advanced lithium rechargeable batteries such as lithium-air and lithium-sulfur batteries, owing to its high volumetric and gravimetric energy density. There are, however, two major challenges limit its practical application, which are the lithium dendrite growth and low Coulombic efficiency. Here, we demonstrate that the lithium dendrite growth and continuous decomposition of electrolyte can be effectively suppressed by constructing ideal porous TiO2 modified Cu electrodes (PTCEs) and building a stable solid electrolyte interphase (SEI). On the one hand, PTCEs can provide ample space for lithium deposition, alleviating the huge volumetric variation during cycling. On the other hand, the originally formed LixTiO2 can work as a hybrid ionic/electronic conductor, reducing the lithium nucleation overpotential. Combined with additives of fluoroethylene carbonate (FEC) and LiNO3, electrolyte decomposition has been further inhibited. As a result, the Coulombic efficiency of lithium plating/stripping is highly stable at 98.6% for more than 150 cycles.