This study presents a novel strategy for suppressing lithium dendrite growth in lithium metal batteries (LMBs) by constructing an artificial solid electrolyte interphase (SEI) layer using a lithium nitrate (LiNO₃)-implanted electroactive β-phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The PHL layer, which is highly polar, captures Li ions on its surface to form Li-ion charged channels. These channels act as reservoirs to sustainably release Li ions, compensating for the ionic flux of the electrolyte and reducing Li dendrite growth. The stretched molecular channels also accelerate Li ion transport, leading to uniform Li deposition and enhanced electrochemical performance. The PHL layer significantly improves the Coulombic efficiency (CE) of Li metal anodes, achieving a CE of 97.0% over 250 cycles in Li|Cu cells and a stable symmetric plating/stripping behavior under high Li utilization of 50%. In full cells, the PHL-Cu@Li anode with LiFePO₄ (LFP) cathode exhibits a high-capacity retention of 95.9% after 900 cycles, while the PHL-Cu@Li anode with LiNi₀.₈₇Co₀.₁Mn₀.₀₃O₂ (NCM) cathode maintains a discharge capacity of 170.0 mAh g⁻¹ with a capacity retention of 84.3% after 100 cycles, even under harsh conditions of an extremely low N/P ratio of 0.83. The PHL layer also enables long cycle life in symmetric cells, with the LillLi cell operating for over 2000 hours at 3 mA cm⁻² with 50% Li utilization. The PHL layer is composed of PVDF-HFP and LiNO₃, which are combined to form a composite film. The PHL layer exhibits high ionic conductivity and enhances the Li⁺ transference number, which is crucial for efficient Li ion transport and uniform deposition. The PHL layer also promotes the formation of a stable SEI layer enriched with Li₃N and nitrogen-containing species, which improves the stability of the electrode/electrolyte interface and suppresses Li dendrite growth. The study demonstrates that the PHL layer is an effective strategy for enhancing the performance of LMBs, particularly in ester-based electrolytes. The PHL layer not only suppresses Li dendrite growth but also improves the cycle stability and capacity retention of LMBs, making it a promising candidate for practical high-voltage LMBs.This study presents a novel strategy for suppressing lithium dendrite growth in lithium metal batteries (LMBs) by constructing an artificial solid electrolyte interphase (SEI) layer using a lithium nitrate (LiNO₃)-implanted electroactive β-phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The PHL layer, which is highly polar, captures Li ions on its surface to form Li-ion charged channels. These channels act as reservoirs to sustainably release Li ions, compensating for the ionic flux of the electrolyte and reducing Li dendrite growth. The stretched molecular channels also accelerate Li ion transport, leading to uniform Li deposition and enhanced electrochemical performance. The PHL layer significantly improves the Coulombic efficiency (CE) of Li metal anodes, achieving a CE of 97.0% over 250 cycles in Li|Cu cells and a stable symmetric plating/stripping behavior under high Li utilization of 50%. In full cells, the PHL-Cu@Li anode with LiFePO₄ (LFP) cathode exhibits a high-capacity retention of 95.9% after 900 cycles, while the PHL-Cu@Li anode with LiNi₀.₈₇Co₀.₁Mn₀.₀₃O₂ (NCM) cathode maintains a discharge capacity of 170.0 mAh g⁻¹ with a capacity retention of 84.3% after 100 cycles, even under harsh conditions of an extremely low N/P ratio of 0.83. The PHL layer also enables long cycle life in symmetric cells, with the LillLi cell operating for over 2000 hours at 3 mA cm⁻² with 50% Li utilization. The PHL layer is composed of PVDF-HFP and LiNO₃, which are combined to form a composite film. The PHL layer exhibits high ionic conductivity and enhances the Li⁺ transference number, which is crucial for efficient Li ion transport and uniform deposition. The PHL layer also promotes the formation of a stable SEI layer enriched with Li₃N and nitrogen-containing species, which improves the stability of the electrode/electrolyte interface and suppresses Li dendrite growth. The study demonstrates that the PHL layer is an effective strategy for enhancing the performance of LMBs, particularly in ester-based electrolytes. The PHL layer not only suppresses Li dendrite growth but also improves the cycle stability and capacity retention of LMBs, making it a promising candidate for practical high-voltage LMBs.