Based on the principles of bionics, a PCM capsule in red blood cell (RBC) shape is proposed in this paper. The RBC-shaped capsule, as well as its deformation structure (cylinder, drum, ring and spherical ball), was fabricated by a 3D printing method. An experimental set-up was developed for investigating the thermal performance in cold charging process. An experimentally validated numerical investigation was also conducted on the ANSYS Fluent software. In the simulation, thermal performances such as the liquid fraction variation, temperature distribution and cold charging rate of the capsules were studied. The results demonstrated that the RBC-shaped capsule had the best thermal performance and the spherical capsule had the worst performance. The cold charging rate of the RBC-shaped capsule was 2.12 times that of the spherical capsule.