Sodium ion batteries would have more and more applications in the foreseeable future where electricity would gradually replace traditional fossil fuels. Although slightly inferior in some performance to lithium-ion batteries, their more cost-effective characteristics have always attracted attention. In order to better utilize sodium ion batteries, many researchers are improving and preparing their electrode materials, and the physical properties of the electrode materials naturally determine their performance. Therefore, this article decided to calculate the first principles of electrode materials based on density functional theory to determine the physical properties of the materials. Finally, this article successfully applied density functional theory by taking the three-dimensional position of Na2FePO4F/C atoms, as well as the ion conductivity of the electrolyte and its discharge power between Na2FeP2O7 positive electrode half cells as examples.