Electrospun LiFePO₄/C Composite Fiber Membrane as a Binder-Free, Self-Standing Cathode for Power Lithium-Ion Battery

A LiFePO₄/C composite fiber membrane was fabricated by the electrospinning method and subsequent thermal treatment. The thermal decomposition process was analyzed by TG/DSC, the morphology, microstructure and composition were studied using SEM, TEM, XRD, Raman, respectively. The results indicated that the prepared LiFePO₄/C composite fibers were composed of nanosized LiFePO₄ crystals and amorphous carbon coatings, which formed a three dimensional (3D) long-range networks, greatly enhanced the electronic conductivity of LiFePO₄ electrode up to 3.59× 10⁻² S · cm⁻². The 3D LiFePO₄/C fiber membrane could be directly used as a binder-free, self-standing cathode for lithium-ion battery, and exhibited an improved capacity and rate performance. The LiFePO₄/C composite electrode delivered a discharge capacity of 116 mAh·g⁻¹, 109 mAh·g⁻¹, 103 mAh·g⁻¹, 91 mAh·g⁻¹, 80 mAh·g⁻¹ at 0.1 C, 0.5 C, 1 C, 3 C, 5 C, respectively. And a stable cycling performance was also achieved that the specific capacity could retain 75 mA·g⁻¹ after 500 cycles at 5 C. Therefore, this LiFePO₄/C composite fiber membrane was promising to be used as a cathode for power lithium ion battery.