CN-122025741-A - Sodium secondary battery, method for manufacturing same, and electric device

CN122025741ACN 122025741 ACN122025741 ACN 122025741ACN-122025741-A

Abstract

The application provides a sodium secondary battery, a manufacturing method thereof and an electric device, wherein the sodium secondary battery comprises a non-negative electrode sodium metal battery or a sodium metal battery, the sodium secondary battery comprises a negative electrode plate, a solid electrolyte interface film and electrolyte, the solid electrolyte interface film is positioned on at least one side of the negative electrode plate, the solid electrolyte interface film comprises boron element, and the electrolyte comprises phthalocyanine salt additive. The sodium secondary battery provided by the application has good cycle performance and storage performance.

Inventors

OUYANG CHUYING
ZHANG YUAN
GUAN YINGJIE
WEN YAN
HUANG HUIYING
BAI WEIWEI
WANG YAQI

Assignees

宁德时代新能源科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (10)

1. A sodium secondary battery, wherein the sodium secondary battery comprises a non-negative sodium metal battery or a sodium metal battery, the sodium secondary battery comprising: A negative electrode plate; a solid electrolyte interface film located on at least one side of the negative electrode tab, the solid electrolyte interface film comprising elemental boron; electrolyte comprising a phthalocyanine salt additive.
2. The sodium secondary battery according to claim 1, wherein the electrolyte further comprises borate; Optionally, the borate comprises one or more of sodium tetrafluoroborate, potassium tetrafluoroborate, lithium tetrafluoroborate, and aluminum tetrafluoroborate; optionally, the borate is present in the electrolyte at a molar concentration of 0.03mol/L to 0.3mol/L.
3. The sodium secondary battery according to claim 2, wherein the electrolyte further comprises a sodium salt comprising sodium hexafluorophosphate.
4. The sodium secondary battery according to claim 1, wherein the mass percentage of the phthalocyanine salt additive in the electrolyte is 0.01% -1%; Optionally, the mass percentage of the phthalocyanine salt additive in the electrolyte is 0.1% -1%; optionally, the mass percentage of the phthalocyanine salt additive in the electrolyte is 0.2% -0.5%; optionally, the phthalocyanine salt additive comprises one or more of potassium phthalocyanine, lithium phthalocyanine, cobalt phthalocyanine, zinc phthalocyanine, copper phthalocyanine, sodium phthalocyanine, platinum phthalocyanine, palladium phthalocyanine, nickel phthalocyanine and manganese phthalocyanine.
5. The sodium secondary battery according to any one of claims 1 to 4, wherein the electrolyte further comprises an ether-type organic solvent; optionally, the ether-based organic solvent comprises a linear ether and/or a cyclic ether; Optionally, the linear ether comprises one or more of ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and diethylene glycol dibutyl ether; optionally, the cyclic ether includes one or more of tetrahydrofuran, methyltetrahydrofuran, and cyclic ethers such as 1, 3-dioxolane.
6. The sodium secondary battery according to claim 5, wherein the mass percentage b1 of the linear ether in the electrolyte and the mass percentage b2 of the cyclic ether in the electrolyte satisfy 1≤b1/b 2≤9; Alternatively, b1 is more than or equal to 33% and less than or equal to 75%; alternatively, 6% or more and 43% or less of b 2.
7. The sodium secondary battery according to claim 1, further comprising a positive electrode sheet comprising a positive electrode active material comprising at least one of a layered oxide, a polyanion compound, and a prussian blue compound; Optionally, the chemical formula of the layered oxide is Na x M y O 2 , wherein x is 0< 4.5, y is 0< 1, and M element comprises at least one of Ti, V, cr, fe, cu, zn, sr, Y, zr, nb, mo, cd, sn, sb, te, ba, ta, W, yb, la and Ce; Optionally, the M element includes at least one of Ti, V, cr, fe, co, mn, ni, cu and Zn.
8. A sodium secondary battery comprising an electrolyte comprising a sodium salt, a phthalocyanine salt additive, a borate, and an ether organic solvent.
9. A method for manufacturing a sodium secondary battery, comprising: providing an electrode assembly comprising a negative electrode tab, and packaging the electrode assembly; injecting an electrolyte into the packaged electrode assembly, wherein the electrolyte comprises a phthalocyanine salt additive, a borate, a sodium salt and an ether organic solvent: and forming the electrode assembly after the electrolyte is injected into the electrolyte, so that at least one side of the negative electrode plate forms a solid electrolyte interface film to obtain the sodium secondary battery, wherein the sodium secondary battery comprises a non-negative sodium metal battery or a sodium metal battery, and the solid electrolyte interface film comprises boron.
10. An electric device comprising a sodium secondary battery selected from the group consisting of the sodium secondary batteries according to any one of claims 1 to 8 and/or the sodium secondary battery produced by the production method according to claim 9.

Description

Sodium secondary battery, method for manufacturing same, and electric device Technical Field The application relates to the technical field of sodium secondary batteries, in particular to a sodium secondary battery, a manufacturing method thereof and an electric device. Background The secondary battery is used as an electric energy storage device and is increasingly widely applied to the fields of transportation, aerospace, ships, energy storage and the like. With the popularization and application of secondary batteries in various fields, it is desired to reduce the manufacturing cost of secondary batteries while the demands for cycle performance, storage performance, safety performance, low-temperature performance, and the like are also increasing. In recent years, sodium secondary batteries have been the focus of many enterprise researches by virtue of good safety performance and low temperature performance, as well as low manufacturing costs. However, it was found during the research on the sodium secondary battery that the cycle performance and the storage performance of the sodium secondary battery are poor, resulting in further limited applications. Disclosure of Invention The application provides a sodium secondary battery, a manufacturing method thereof and an electric device, wherein the sodium secondary battery has good cycle performance and storage performance. In a first aspect, embodiments of the present application provide a sodium secondary battery comprising a non-negative sodium metal battery or a sodium metal battery, the sodium secondary battery comprising a negative electrode tab, a solid electrolyte interface film on at least one side of the negative electrode tab, the solid electrolyte interface film comprising elemental boron, and an electrolyte comprising a phthalocyanine salt additive. According to the technical scheme, in the electrolyte, the phthalocyanine macromolecules in the phthalocyanine salts have high sodium affinity, can be uniformly distributed and adsorbed and diffused on the surface of the boron-containing solid electrolyte interface film to form a coating similar to a planar molecular level, and are reduced into sodium metal in the negative electrode plate through complexing sodium ions in the electrolyte. The phthalocyanine macromolecules not only can promote the uniform distribution of Na + flux, but also can improve the transfer number of Na + ions and reduce the influence of space charge effect on sodium deposition, so that the current density distribution and the uniformity of the sodium deposition surface in the sodium deposition process can be improved when the sodium secondary battery is used, the growth amount of sodium dendrites is reduced to reduce the occurrence of internal short, and the cycle performance of the sodium secondary battery is improved. The boron-containing solid electrolyte interface film can reduce the occurrence of direct contact between the phthalocyanine salt additive and sodium metal, and further can reduce the occurrence of side reaction between the phthalocyanine salt additive and sodium metal, so that the storage performance and the cycle performance of the sodium secondary battery are improved. In some embodiments of the application, the electrolyte further comprises a borate. In some embodiments of the application, the borate comprises one or more of sodium tetrafluoroborate, potassium tetrafluoroborate, lithium tetrafluoroborate, and aluminum tetrafluoroborate. By adopting the technical scheme, the cycle performance and the storage performance of the sodium secondary battery can be further improved. In some embodiments of the application, the molar concentration of borate in the electrolyte is 0.03mol/L to 0.3mol/L. In some embodiments of the application, the electrolyte further comprises a sodium salt, including sodium hexafluorophosphate. In some embodiments of the application, the phthalocyanine salt additive is present in the electrolyte at a mass percent of 0.01% to 1%. In some embodiments of the application, the phthalocyanine salt additive is present in the electrolyte at a mass percent of 0.1% to 1%. In some embodiments of the application, the phthalocyanine salt additive is present in the electrolyte at a mass percent of 0.2% to 0.5%. According to the technical scheme, the cyclic performance and the storage performance of the sodium secondary battery can be improved by controlling the mass percentage of the phthalocyanine salt additive in the electrolyte. In some embodiments of the application, the phthalocyanine salt additive comprises one or more of potassium phthalocyanine, lithium phthalocyanine, cobalt phthalocyanine, zinc phthalocyanine, copper phthalocyanine, sodium phthalocyanine, platinum phthalocyanine, palladium phthalocyanine, nickel phthalocyanine, and manganese phthalocyanine. According to the technical scheme, the phthalocyanine salt additive can further improve the cycle performance of the sodium secondary