Intelligent Nano-Colloidal Electrolytes for Stabilizing Lithium Metal Anodes: A Review

Although Li-metal has been revisited as the most attractive anode in building high-energy-density batteries owing to its superiority, such as ultimate theoretical capacity and lowest working voltage, notorious Li dendrite growth has plagued its practical uses. Since dendritic Li electroplating is mostly caused by poor Li+ transport and inferior stability of solid-electrolyte interphase (SEI), an innovative reframing of the electrolyte is crucial to the success of Li-metal anodes (LMAs). This review presents a new class of electrolytes, nano-colloidal electrolytes (NCEs), providing a new avenue for next-generation Li-metal batteries (LMBs). Without searching for new salts/solvents or their compositional tuning, NCEs exploiting multi-functional nanoparticles dispersed in liquid electrolytes can promote Li+ transport and reinforce the SEI of liquid electrolytes that are solely used. This review discusses various types of nanoparticles and their key roles in demonstrating excellent suppression of Li dendrite growth and enhancing the cycling stability of LMBs. Unraveling the underlying design principles of NCEs offers practical solutions for stabilizing LMAs, paving the way for developing intelligent battery systems. Li metal batteries suffer from Li dendrite formation problems owing to inferior Li+ transport and poor SEI. Nano-colloidal electrolytes (NCEs) containing nanoparticles in liquid electrolytes can modify the Li+ microenvironment and Li metal interface chemistry. Additionally, NCE has recently focused on granting smart functionality to nanoparticles to suppress Li dendrite formation.image