Slurry-like hybrid electrolyte with high lithium-ion transference number for dendrite-free lithium metal anode

Abstract Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems, due to the lowest negative electrochemical potential and super high theoretical specific capacity. However, the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application. In this work, a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode, which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part. The hybrid electrolyte shows high ionic conductivity (3.89 × 10−3 S cm−1 at 25°C) and lithium-ion transference number (0.88). Especially, the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte, while the viscosity of hybrid electrolyte increases. It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite. Stable cycling of Li/Li cells at a current density up to 1 mA cm−2 is possible. The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal. This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.