Appropriate proportion truncated octahedron LiNi0.5Mn1.5O4 with excellent electrochemical properties for lithium-ion batteries prepared by graphite-assisted calcination method

LiNi0.5Mn1.5O4 materials with different crystal surface proportions are synthesized by graphite-assisted calcination method. Scanning electron microscopy (SEM) reveals homogeneous microsized polyhedral morphology with different proportions of exposed {100} and {111} surfaces. The most highlighted result is that LiNi0.5Mn1.5O4 with appropriate proportion exposed {100} and {111} surfaces can achieve both high power and long lifetime simultaneously. The LiNi0.5Mn1.5O4 with appropriate proportion exposed {100} and {111} surfaces can provide a large capacity of 74.8 mAh g−1 even at a discharge rate as high as 20 C. Besides, the capacity retentions of the LiNi0.5Mn1.5O4 with appropriate proportion exposed {100} and {111} surfaces are found to be 93.33% at 1 C after 100 cycles. These results represent the experimental evidence for lattice-plane anisotropy in LiNi0.5Mn1.5O4 crystals. Moreover, the LiNi0.5Mn1.5O4 with appropriate proportion exposed {100} and {111} surface structure is beneficial for obtaining high volumetric energy density and excellent processability in practical applications.