Spatially hierarchical carbon enables superior long-term cycling of ultrahigh areal capacity lithium metal anodes

A leaf-vein-inspired spatially modulated host strategy is proposed for lithium anodes, and a self-supporting carbon membrane with vertical micro-channels blanketed by carbon nanofiber mats is developed. In such a spatially modulating design, the low-tortuosity channeling membrane allows rapid transport of lithium ions in the long range and better accommodation of the volume change upon cycling. More importantly, in the short range, the nanofiber mats confer strong capillarity and function as localized micro-reservoirs to hold up the electrolyte, thereby promoting uniform lithium ion distribution and scalable lithium deposition. Impressively, the fabricated electrodes exhibited outstanding cycling stability under various conditions of high areal capacity (up to 40 mAh cm−2) and high current density (up to 40 mA cm−2), including exceptionally stable dendrite-free cycling up to 1,080 cycles at 30 mAh cm−2 and 10 mA cm−2. This study offers a spatially hierarchical paradigm for rational design and construction of viable metal battery anodes.