Sodium secondary battery and electric device

Abstract

The invention provides a sodium secondary battery and an electric device. The secondary battery comprises a positive pole piece, a negative pole piece, an isolating membrane and an electrolyte; the negative pole piece comprises a negative current collector or comprises a negative current collector and a sodium metal layer arranged on the surface of the negative current collector; the electrolyte comprises colloidal particles, electrolyte salt and a solvent; a Raman spectrum of the electrolyte comprises a first Raman characteristic peak with the Raman shift ranging from 815 cm <-1 > to 825 cm <-1 > and a second Raman characteristic peak with the Raman shift ranging from 845 cm <-1 > to 855 cm <-1 >, and the peak area A1 of the first Raman characteristic peak and the peak area A2 of the second Raman characteristic peak meet the condition that (A1 + A2) / S1 is smaller than or equal to 30%, and S1 represents the sum of the peak areas of all characteristic peaks appearing in the Raman spectrum in a Raman shift range of 800 cm <-1 > to 900 cm <-1 >. The sodium secondary battery has both high capacity and high safety performance.

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