Understanding the correlation between physical and electrochemical/chemical properties are significantly crucial for development of electrode materials for lithium ion batteries. Among the materials, Ni-rich cathode materials with high energy density has degradation issue of electrochemical performance due to the parasitic reaction at the cathode electrolyte interface. The core-shell or concentration gradient materials consisting of a high-Ni core and a relatively high-Mn outer layer might be potential candidate providing improved stability as well as cycle life performance. In this respect, the porosity of final sintered particle can be an indicator to affect the electrode stability. The strategy to tune the particle porosity is introduced by controlling a feed rate of reactants during co-precipitation synthesis. The structural characteristics was compared for the materials obtained by different feed rate X-ray diffraction, electron microscopy, electrochemical performances, particle size distribution and porosity. The interfacial kinetic reaction between the Ni-rich cathode and a nonaqueous electrolyte at different SOCs is investigated by our home-built high-precision leakage current measurement system. This study can be an indicator for the safety of Ni-rich cathode by co-precipitation.