No abstract

Li metal is the optimal choice as an anode due to its high theoretical capacity, but it suffers from severe dendrite growth, especially at high current rates. Here, an ionic gradient and lithiophilic inter‐phase film is developed, which promises to produce a durable and high‐rate Li‐metal anode. The film, containing an ionic‐conductive Li0.33La0.56TiO3 nanofiber (NF) layer on the top and a thin lithiophilic Al2O3 NF layer on the bottom, is fabricated with a sol–gel electrospinning method followed by sintering. During cycling, the top layer forms a spatially homogenous ionic field distribution over the anode, while the bottom layer reduces the driving force of Li‐dendrite formation by decreasing the nucleation barrier, enabling dendrite‐free plating‐stripping behavior over 1000 h at a high current density of 5 mA cm−2. Remarkably, full cells of Li//LiNi0.8Co0.15Al0.05O2 exhibit a high capacity of 133.3 mA h g−1 at 5 C over 150 cycles, contributing a step forward for high‐rate Li‐metal anodes.

Li-metal anodes promise to build high-energy-storage systems, but they suffer from safety problems from severe dendrite growth. Here, we develop a thin and conformal hybrid ionic and electronic conducting metal-oxide nanofiber interface to stabilize Li-anodes without forming dendrites. The thin ionic-conductive Li0.33La0.56TiO3 (LLTO) nanofiber film is first fabricated by electrospinning followed by pyrolysis. After connecting with the electrolytes-wetted Li-metal anodes, due to the self-driven chemical reactions, LLTO is reduced, and a hybrid conducting interface is developed. The interface can act as a reservoir to redistribute the nonuniform Li-ion flux above the anode surface and reduce the driving force of dendrite formation by leveling electric potential distribution, enabling a stable Li plating-stripping with a low overpotential of 80 mV over 800 h at a high current of 5 mA/cm2. More practically, the Li-LiNi0.8Co0.15Al0.05O2 cells deliver a high capacity of 147 mA h/g at 1 C with a Coulombic efficiency of 99% over 150 cycles, offering prospects to achieve reliable Li-metal batteries.