Composite Lithium Metal Anodes with Lithiophilic and Low-Tortuosity Scaffold Enabling Ultrahigh Currents and Capacities in Carbonate Electrolytes

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.

Automated summary

The composite Li metal anode supported by TiO2/PVP nanofibers can effectively address the dendrite growth issue, improve the safety and cyclability of batteries, and achieve stable cycling at high areal capacities and current densities. This unique structure enables stable cycling under ultrahigh currents and ultra-deep plating/stripping, showing potential for balancing high-energy density and high-power density in Li metal batteries.