Conversion–Lithiophilicity Hosts Toward Long-Term and High-Energy-Density Lithium Metal Batteries

Lithium metal anode emerges as an ideal candidate for the next generation of high-energy-density batteries. However, challenges persist in achieving high lithium utilization rates while maintaining the demands of high energy density and extended cycle life. In this work, a novel conversion–lithiophilicity strategy is proposed to regulate the longevity of high-energy-density batteries by injecting lithium ion activity. This strategy is validated through carbon nanofiber decorated with Fe₃C and Fe₂O₃ particles. The uniform metallic lithium deposition induced by lithiophilic Fe₃C substrates has been verified through lithium deposition/stripping experiments and density functional theory calculations. The electrochemical active Fe₂O₃ component supplies additional anodic capacity and suppress battery degradation, as demonstrated in lithium-ion storage research and three electrode system studies. When paired with LiFePO₄ cathodes at an N/P ratio of 2, the full battery showcases outstanding cycling stability over 300 cycles at 1C, with an exceptional energy density of 438 Wh kg⁻¹ (calculated based on the cathode material and lithium content). Furthermore, the full battery delivers rapid kinetics of 124 mAh g⁻¹ at 2C. The conversion–lithiophilicity strategy presented offers a promising avenue for the development of high-energy density and long-life lithium metal batteries.