Characterization of cathode from LiNi_xMn_2-xO₄ nanofibers by electrospinning for Li-ion batteries

Ni substituted LiMn₂O₄ nanofiber cathode materials (LiNi_xMn_2-xO₄, x = 0.2, 0.3, 0.4, 0.5) have been prepared by a combination of electrospinning and sol-gel techniques. The nanofiber cathode materials appear to have a porous "network-like" morphology with nanosized diameters of ∼120 nm and microsized lengths of >5 μm. The structure provides short lithium diffusion paths and a large surface area, facilitating rapid charge-discharge characteristics. The Ni substitution not only mitigated the Jahn-Teller distortion effect but also greatly suppressed the Mn dissolution, which improved the rate capability and cycle performance. The LiNi_0.4Mn_1.6O₄ nanofiber cathode exhibits excellent rate capability and cycle performance both at room temperature and at 55 °C. Thus, the LiNi_0.4Mn_1.6O₄ nanofibers may be a potential cathode material for high rate discharge lithium ion batteries.