Inorganic-Rich and Flexible Solid-Electrolyte Interphase Formed Over Dipole-Dipole Interaction for Highly Stable Lithium-Metal Anodes

The uncontrollable lithium (Li) dendrite growth and unstable solid electrolyte interfaces (SEI) hinder the practical application of Li metal batteries (LMBs). Herein, a PAN/CNTs-based SiO 2 -modified vertical-cavity film (PCS-VCF) with a network structure is prepared by a simple spin-coating process to address these challenges. This new current collector with a polar lithiophilic network stabilizes the Li metal anodes by regulating the chemical environment in carbonate electrolytes. The dipole interaction between the CN groups and the CO groups reduces the high reactivity of the carbonates in the electrolyte, forming an SEI layer with higher inorganic components and enhancing the stability of the electrode/electrolyte interface. The special vertical-cavity network structure inside the current collector can decrease local current density and suppress the huge volume expansion of Li metal during the cycling process. Consequently, a high-performance Li metal anode with dendrite-free morphology is achieved (over 1500 cycles with low overpotential at 20 mA cm −2 in symmetric cells). Furthermore, full cell with the LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode delivers a stable capacity of 164.5 mA h g −1 for 500 cycles at 5 C, with a capacity decay rate of 0.077% per cycle.