Title: Composite Lithium Metal Anodes with Lithiophilic and Low‐Tortuosity Scaffold Enabling Ultrahigh Currents and Capacities in Carbonate Electrolytes
Abstract: The practical application of lithium metal anode has been hindered by safety and cyclability issues due to the uncontrollable dendrite growth, especially during fast cycling and deep plating/stripping process. Here, a composite Li metal anode supported by periodic, perpendicular, and lithiophilic TiO2/poly(vinyl pyrrolidone) (PVP) nanofibers via a facial rolling process is reported. TiO2/PVP nanofibers with good Li affinity provide low‐tortuosity and directly inward Li+ transport paths to facilitate Li nucleation and deposition under high areal capacities and current densities. The micrometer‐scale interspaces between TiO2/PVP walls offer enough space to circumvent the huge volume variation and avoid structure collapsing during the repeated deep Li plating/stripping. The unique structure enables stable cycling under ultrahigh currents (12 mA cm−2), and ultra‐deep plating/stripping up to 60 mAh cm−2 with a long cycle life in commercial carbonate electrolytes. The gassing behavior in operating pouch cells is observed using ultrasonic transmission mapping. When paired with LiFePO4 (5 mAh cm−2), sulfur (3 mAh cm−2), and high‐voltage LiNi0.8Co0.1Mn0.1O2 cathodes, the composite Li anodes deliver remarkably improved rate performance and cycling stability, demonstrating that it could be a promising strategy for balancing high‐energy density and high‐power density in Li metal batteries.