The Effect of Silver Particle Distribution in a Carbon Nanocomposite Interlayer on Lithium Plating in Anode-Free All-Solid-State Batteries

Solid-state batteries can outperform lithium-ion batteries in energy per unit mass and per unit volume when operating with a Li metal anode. However, metallic Li anodes pose significant manufacturing challenges. Anode-free cells avoid these challenges by plating metallic Li at the anode on the first charge, but subsequent non-uniform cyclic Li stripping and plating encourages unwanted Li dendrite growth, decreased coulombic efficiency, and early cell failure. We report a new spray-printed nanocomposite bilayer of silver/carbon black (Ag/CB) between the anodic current collector and Li6PS5Cl solid electrolyte with Ag concentrated at the current collector. Compared with previous Ag/CB mixtures, the bilayer ensured more uniform Li anode formation and improved cycling performance. Cells with a high-Ni oxide cathode had initial discharge capacity > 190 mAh/g and coulombic efficiency > 98% over 100 cycles. The Li plating uniformity with the structured Ag/CB interlayer was confirmed using secondary-ion mass spectrometry (SIMS) imaging.