Three-dimensional (3D) porous materials of Sn–Ni alloy with reticular structure were prepared by electroplating using copper foam as current collector. The structure and electrochemical performance of the electroplated 3D porous Sn–Ni alloys were investigated in detail. Experimental results illustrated that the 3D porous Sn–Ni alloy consists of mainly Ni3Sn4 phase with a hexagonal structure. Galvonostatic charging/discharging of annealed 3D porous Sn–Ni alloy confirmed its excellent performances: at 50th charge–discharge cycle, the discharge specific capacity is 505mAhg−1 and the corresponding charge (delithiation) specific capacity is 501mAhg−1, yielding columbic efficiency as high as 99%. It has revealed that the porous structure of the alloy can restrain the pulverization of electrode in charge/discharge cycles, and accommodate partly the volume expansion and phase transition, resulting in a significant improvement of cycle life of the Sn–Ni electrode.