Novel Cu1.8Se carbon fiber composite for aluminum-ion battery cathode materials: Outstanding electrochemical performance

Selenides exhibit high energy density and long-cycle stability as aluminum-ion batteries cathode materials. It can provide a high number of electron transfer in the electrochemical reaction. Therefore, the selenides cathode material exhibits an outstanding initial specific capacity. Herein, one-dimensional Cu1.8Se nanofibers were prepared by electrospinning and high-temperature selenization. By changing the selenization temperature, Cu1.8Se-600, 800, 1000 were synthesized at 600, 800, and 1000 °C, respectively. Among them, Cu1.8Se-1000 has the highest crystallinity and the smallest grain size. High crystallinity means a high proportion of crystalline regions, and the crystal structure facilitates the intercalation/extraction of ions due to the ordered arrangement of molecules in three-dimensional space. Therefore, Cu1.8Se-1000 has an outstanding performance. Cu1.8Se-1000 exhibited the best electrochemical performance in the test: 152.12 mAh/g after 5000 cycles at 2.0 A/g. The obtained cathode material was assembled into a pouch battery, and the battery could still light up the diode in the folded state, which indicated the application prospect of this new cathode material in wearable devices.