Metal-Organic Frameworks as Electrolyte Additives To Enable Ultrastable Plating/Stripping of Li Anode with Dendrite...

Suppressing the extrusion of Li dendrites and alleviating the volume expansion of Li anode during long-term cycling are of great significance to achieve highly reversible Li metal batteries of high energy density potential. However, the exploration of facile and effective solutions to smoothen anode surface is still a big challenge. Here, we propose a solid additive strategy by blending tailored metal-organic framework (MOF) grains with typical carbonate electrolyte to enable an ultrastable plating/stripping cycling of Li anode for at least 1400 h with evident inhibition of anode roughening and voltage polarization. Zr-based MOF (UiO-66) additive enables the smallest nucleation and plateau overpotentials (∼80 mV) during Li plating especially under high current density (2 mA/cm²) and large areal capacity (4 mAh/cm²). The kinetic and cyclic advantages of Li anode modulated by UiO-66 not only benefit from its intrinsic features (high surface area/porosity and thermal/electrochemical stability) but also from the reinforced solid electrolyte interface with low resistance, which consists of concentrated LiF and robust Zr-O-C moieties. Li-Li₄Ti₅O₁₂ cell based on MOF additive can achieve a high reversibility for at least 900 cycles.