The invention belongs to the technical field of
sodium-
ion batteries, and particularly discloses a three-dimensional composite negative
electrode material of a
sodium-
ion battery as well as a preparation method and application of the three-dimensional composite negative
electrode material. The three-dimensional composite negative
electrode material FePS3 / rGO of the
sodium ion battery has a
lamellar structure, and tiny FePS3 nanosheets are uniformly attached to the surface of a rGO lamellar layer. FePS3 is a ternary
transition metal phosphorus sulfide and has a special two-dimensional
layered structure, the
layers are combined by
Van der Waals force, and the structure is beneficial to the rapid movement and storage of sodium ions between the
layers. According to the present invention, FePS3 and rGO are compounded, so that
volume expansion of the FePS3 material in a reaction process is effectively buffered, the rapid transfer of electrons / ions is promoted, and a longer cycle life can be realized on the premise of keeping higher specific capacity. Meanwhile, the improvement of the stability of a
material system also greatly enhances the rate capability of the material, and the
sodium ion battery prepared from the material has high
discharge capacity and excellent rate capability.