A new Energy-Storage Slip-Clutch Motor (ESSCM) was proposed for transient high-power and large torque driving. In this paper, motors of different inner rotor structures and materials are compared with respect to the value of starting torque and starting time. Two structures of distributed composite rotor and interval composite rotor are analyzed. Motors of different slot types are also studied based on solid rotor in view of eddy-current loss. With finite element analysis (FEA), the effect of different slot shapes of solid inner rotor as well as composite inner rotor is further analyzed. Steel Q235 solid rotor has the best starting performance and motor with circle slot cost least energy loss. The results in this paper provide foundation to the optimal design of inner rotor.