Submicrometric LiNi0.5Mn1.5O4 cathode material is prepared using a combination of electrospinning and annealing. Well-separated nanofiber precursors impede the growth and agglomeration of LiNi0.5Mn1.5O4 particles. It is proved that submicrometric LiNi0.5Mn1.5O4 (ca. 150-200 nm) with Fd3m space group exhibits favorable electrochemical performance. At 0.1 C rate, it shows an initial discharge capacity of 132.7 mA h g(-1) with capacity retention over 96% after 100 cycles. Under the rate of 5C, it can still deliver a discharge capacity of 116.7 mA h g(-1).