High-yield carbon nanofibers derived from nanoporous Cu catalyst alloyed with Ni for sodium storage with high cycling stability

High-performance and low-cost anode materials are critical for superior sodium-ion batteries (SIBs). Herein, high-yield porous carbon nanofiber (CNF) anode materials (named CNFs@Cu–Ni) are prepared by chemical vapor deposition using a specialized nanoporous Cu–Ni alloy catalyst. Density functional theory calculations indicate that Ni incorporation results in a shift of the d-band center of the catalyst from −2.34157 eV to −1.93682 eV. This phenomenon elucidates the remarkable adsorption capacity of the Cu–Ni catalyst toward C₂H₂, thereby facilitating the catalytic growth of high-performance CNFs. With this approach, a superior yield of 258.6% for deposited carbon is reached after growth for 1 h. The CNFs@Cu–Ni anode presents an outstanding discharge capacity of 193.6 mAh·g⁻¹ at 1 A·g⁻¹ over 1000 cycles and an exceptional rate capability by maintaining a capacity of 158.9 mAh·g⁻¹ even at 5 A·g⁻¹ in an ether-based electrolyte. It also exhibits excellent performance in the CNFs@Cu–Ni//NVP full battery attributed to the presence of abundant Na⁺ adsorption sites on its surface. This study presents a new concept for the advancement of high-performance carbonaceous electrodes for SIBs.