An analytical model is proposed, and the analysis is conducted for solid oxide fuel cells in order to achieve higher power densities. The analytical model is designated to help designers to optimize the current collector sizes and spacing, and also the geometrical shapes of the current collectors as well. The analytical model basically has a whole consideration about the ohmic polarization, the species concentration polarization, and the activation polarization; while the load of optimization computations and analysis is greatly alleviated for engineering designers. From the analysis of several cases, it is recommended that 3D pillars be used for the current collectors in SOFCs incorporating with appropriate measures of a uniform flow distribution. It is also clear that unless limited by the fabrication technologies for the bipolar plates, a smaller control area and current collectors are preferable to SOFCs to have higher power densities.