Intercalation Mechanism of C2N/Blue Phosphorene for Li-Ion Batteries: Ultrahigh Capacity, Fast Kinetics and Improved Compatibility with FSI/FEC Electrolytes

Abstract

Despite their complementary merits, each material faces inherent limitations when used independently. Blue phosphorene (BlueP) is prone to oxidative degradation and structural instability, whereas nitrogenated holey graphene (C2N), although chemically robust and electronically versatile, is limited by structural defects and uncertainties in Li+ adsorption mechanisms. Therefore, constructing a C2N/BlueP heterostructure offers a rational strategy to synergistically combine their advantages, enhancing interfacial electronic coupling, structural stability, and overall lithium-ion storage performance at the atomic level using first-principles computations. Our results demonstrate that C2N/BlueP serves as a highly promising anode material, exhibiting exceptional structural stability, strong ion binding affinity, intrinsic metallic behavior after Li-adsorption, high theoretical specific capacity (1023.40 mAh/g), and a moderate open circuit voltage (0.52 V). Li⁺ migration within C2N/BlueP is confirmed to be rapid along the interlayer, owing to a low energy barrier of 0.084 eV and a corresponding diffusion coefficient of 3.88 × 10-2 cm2/s at 300 K. More importantly, C2N/BlueP shows good wettability with common Li-ion battery electrolytes, and among the salts and solvents, FSI and FEC exhibit stronger interfacial interactions than the others, indicating enhanced electrode-electrolyte compatibility. All these characteristics suggest that the designed C2N/BlueP anode is a promising candidate for high-performance LIBs, exhibiting high energy density, favorable rate capability, and strong wettability with electrolytes.