▎ 摘　　要

Na3V2(PO4)(2)F-3 (NVPF) has captured significant heed for cathode materials of sodium-ion battery (SIB), owing to its stable three-dimensional (3D) structure channel that can accommodate Na+ diffusion. However, NVPF is still facing with a major challenge in terms of the electrochemical performance, owing to its uncontrollable morphology. Hence, it was fabricated by using a two-step hydrothermal method, whereby NVPF cuboid particles of homogenous morphology and highly structural symmetry could anchor on the three-dimensional graphene network (GN) structure to form NVPF@GN. The affiliation between the morphology and performance of the NVPF@GN was further probed by manipulating the morphology of the NVPF under diverse heat treatment temperatures. When the temperature reaches 480 degrees C, NVPF@GN manifests prolonged cyclability (the capacity fading rate of 0.01 % cycle(-1) at 0.5 C during 300 cycles) and it shows outstanding rate performance (when the rate is reset to 0.5 C, the capacity is 107 mAh g(-1) and capacity retention is 99 %), which can be ascribed to the high structural symmetry of NVPF@GN. These results indicate that NVPF@GN cuboids can be used as a prospective cathode material for SIBs.