The invention provides a novel secondary battery which comprises a negative
electrode current collector layer, a negative
electrode active material layer, an
electrolyte solution, a positive electrodeactive material layer and a positive
electrode current collector layer which are arranged in sequence, a diaphragm is arranged in the
electrolyte solution, the
electrolyte solution comprises an electrolyte, the electrolyte is an electrolyte
sodium salt, the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material layer isa Na2M2(C2O4)3.2H2O material capable of allowing free intercalation and deintercalation of
sodium ions, and M is at least one of Co, Ni and Mn. The novel secondary battery provided by the invention does not contain a
lithium material and is not restricted by
lithium resources, so that the battery can be developed for a long time, and the production cost is remarkably reduced. Compared with an existing
sodium-
ion battery, the novel secondary battery has the advantages of excellent electrochemical performance, long service life, high capacity
retention ratio, relatively high capacity, and simple, easily obtainable and environmental friendly
anode and
cathode materials, so that the whole battery is simple in production process and low in cost.