3D Printing Lithium Salt towards Dendrite-free Lithium Anodes

Three-dimensional (3D) printing is being progressively utilized to construct various customized architectures for batteries and supercapacitors. Here, 3D printing lithium salt (lithium fluoride, LiF) is developed to construct chemically stable and electrochemically friendly salt scaffolds based on a printable LiF colloidal gel. Owing to the high porosity of LiF scaffolds, lithium-magnesium alloy (Li-Mg) can be facilely infused into the 3D scaffolds towards Li anodes. In the resultant Li anodes, 3D printed LiF scaffolds not only enable to preserve well the integrity of the whole electrodes, but also facilitate the formation of uniform LiF-rich solid electrolyte interphase (SEI) layers, significantly enhancing Li⁺ diffusion rates at Li anode/electrolyte interface; Li-Mg alloy plays a crucial role to promote the uniform nucleation and growth of Li. Consequently, a dendrite-free lithium anode is achieved with an ultralong cycling time of 2000 h, a low overpotential of 18 mV, and good deep Li stripping and plating properties.