Lithium metal batteries (LMBs) are considered ideal next‐generation energy storage systems capable of doubling the energy density of present lithium‐ion batteries. However, their practical application remains challenging at high‐speed charge/discharge rates due to the uncontrollable growth of Li dendrites and the unrestricted volume expansion. Herein, a rationally engineered multifunctional macroporous scaffold inserted into a lithium metal anode is developed to realize ultra‐fast charging while minimizing volume expansion in LMBs. The architecture integrates a polypyrrole (PPy) coating onto an insulating PVDF framework except for the top, effectively suppressing surface Li deposition and mitigating dendrite formation during fast‐charging operation. By introducing a conductivity contrast between the semiconductive PPy and Cu current collector, electron transport is regulated to induce bottom‐up Li deposition. Furthermore, the abundant pyrrolic N sites in the PPy facilitate uniform Li nucleation and enable the formation of a N‐rich SEI layer with high ionic conductivity, enhancing interfacial stability and improving Li plating/stripping kinetics. As a result, at a high‐rate LMB test of 5 C corresponding to 12 min dis/charging, the functionally designed PPy‐coated porous PVDF scaffold demonstrates 94.7% capacity retention over 200 cycles under practical conditions of 1.25 mAh cm −2 loading LFP and 3.2 NP ratio.
Jo et al. (Sun,) studied this question.