Organosilane based artificial solid electrolyte interface layer for stable metallic lithium anode

Owing to its high specific capacity, lithium metals are considered as potential anode candidate for high energy densitylithium-sulfur (Li-S)/lithium-oxygen (Li-O) batteries. However, uncontrollable lithium dendrite growth makes thespontaneously formed solid electrolyte interface layer (SEI) in lithium metal anode (LMA) fragile, preventing cyclic Liplating/stripping process, thereby limiting its usage in high energy density batteries. In this work, we demonstrate anovel organosilane coating strategy, resulting in the formation of artificial SEI (A-SEI) promoting stable operation ofLMA. The presence of epoxide moieties in the coated organosilane induces uniform Li electrodeposition, therebyeffective control over dendrite growth. Symmetric Li/Li cells fabricated using silane coated lithium metal renders stablecycling with the constant over potential value of 40 mV over 800 cycles at the current rate of 4 mA cm
, whencompared to pristine lithium anode. Furthermore, the NMC/Li cell fabricated using modified LMA showed relativelybetter charge/discharge capacity values of 116/115 mAhg coupled with the coulombic efficiency of 99.1 %, after 200cycles at 2C in comparison to pristine lithium based cell (charge/discharge capacity, 91/90 mAhg @2C after 200cycles). Thus, the proposed A-SEI coating strategy enrooted a new pathway for the development of lithium anodes withoutstanding electrochemical characteristics.