▎ 摘　　要

NOVELTY - A symmetrical sodium ion battery comprises positive electrode, negative electrode and electrolyte. The positive electrode and the negative electrode are placed in the electrolyte. The positive electrode comprises positive electrode material. The negative electrode comprises negative electrode material. The active materials of the positive electrode material and the negative electrode material both comprise sodium alum pyrophosphate. USE - Symmetrical sodium ion battery. ADVANTAGE - The symmetrical sodium ion battery has faster sodium ion deintercalation ability, improved multiplying power discharging ability and excellent cycle stability. DETAILED DESCRIPTION - A symmetrical sodium ion battery comprises positive electrode, negative electrode and electrolyte. The positive electrode and the negative electrode are placed in the electrolyte. The positive electrode comprises positive electrode material. The negative electrode comprises negative electrode material. The active materials of the positive electrode material and the negative electrode material both comprise sodium alum pyrophosphate of formula: NaaVb(P2O7)4, where a is 7 plus minus x, b is 3 plus minus y, and x and y are 0-0.5. An INDEPENDENT CLAIM is included for preparation of the symmetrical sodium ion battery, which in using sodium source precursor, vanadium source precursor, and phosphoric acid source precursor.