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 SiO2-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(sic)N groups and the C(sic)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 LiNi0.8Co0.1Mn0.1O2 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.

Automated summary

A PAN/CNTs-based SiO2-modified vertical-cavity film (PCS-VCF) with a network structure is prepared to address the challenges of uncontrollable lithium dendrite growth and unstable solid electrolyte interfaces (SEI) in Li metal batteries (LMBs). The PCS-VCF stabilizes the Li metal anodes by regulating the chemical environment in carbonate electrolytes and suppressing the volume expansion of Li metal. This results in a high-performance Li metal anode with dendrite-free morphology and improved stability of the electrode/electrolyte interface.