Optimized lithium deposition on Ag nanoparticles-embedded TiO₂ microspheres: a facile spray pyrolysis approach for enhanced lithium metal anode

The lithium anode is considered the "holy grail" anode for replacing conventional graphite-based anodes because of its high theoretical capacity and lowest redox potential; however, safety problems arising from the dendritic growth of lithium and large volume fluctuation require resolution to make its commercialization viable. The introduction of a 3D matrix with lithiophilic materials can effectively overcome the challenges that lithium metal batteries associate with commercialization. In this study, we fabricated composite microspheres using TiO(2)( )as an electrochemically stable 3D scaffold and well-dispersed Ag nanoparticles as lithiophilic sites (defined as 600-TiO2-5Ag) via facile spray pyrolysis. Uniquely structured 3D host materials for lithium metal anodes (LMAs) consistently demonstrated stable lithium deposition and stripping performance over 500 cycles while being tested under a current density of 1.0 mA cm(-2 )in an asymmetrical cell. In addition, we studied their lithium storage mechanisms through FIB-TEM analysis. Furthermore, with the deposition of 5.0 mA h cm(-2) of lithium, the symmetric cell exhibited a low overpotential of 24 mV for over 1000 h, and a full cell assembled with commercial LiNi0.8Co0.1Mn0.1O2 (NCM 811) also displayed highly enhanced cell stability and rate capability. This work suggests combining intercalation- and alloying-type materials to synergistically enhance the lithium deposition behavior of LMAs.