CN-122029627-A - Electrolyte composition for sodium-based battery and method for manufacturing same

Abstract

Electrolyte compositions for sodium-based batteries and methods of forming the same are described. The electrolyte composition includes at least one sodium borate salt and a solvent. In some embodiments, the sodium borate is sodium tetra (phenol) borate (NaB [ OC 6 H 5 ] 4 ) or sodium tetra (isopropyl) borate (NaB [ OC 3 H7] 4 ), and the solvent is an ether solvent.

Inventors

• N. Simstock
• BAN CHUNMEI
• E. FRITZ

Assignees

• 科罗拉多州立大学董事会

Dates

Publication Date

20260512

Application Date

20240919

Priority Date

20230919

Claims (15)

1. 1. An electrolyte composition comprising: sodium borate salt selected from the group consisting of sodium tetra (phenol) borate (NaB [ OC 6 H 5 ] 4 ) and sodium tetra (isopropyl) borate (NaB [ OC 3 H 7 ] 4 ), and At least one ether solvent.
2. 2. The electrolyte composition of claim 1, wherein the at least one ether solvent is selected from the group consisting of dimethoxyethane, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and 1, 3-dioxolane.
3. 3. The electrolyte composition of claim 1, further comprising: at least one supplemental sodium salt.
4. 4. The electrolyte composition of claim 3, wherein the at least one supplemental salt is selected from the group consisting of sodium hexafluorophosphate (NaPF 6 ), sodium perchlorate (NaClO 4 ), sodium tetrafluoroborate (NaBF 4 ), sodium tetraphenylborate, sodium nitrate, sodium bis (oxalate) borate, sodium difluoro (oxalate) borate, (sodium trifluoromethylsulfonyl) imide, sodium iodide, and sodium bis (fluorosulfonyl) imide.
5. 5. The electrolyte composition of claim 1, further comprising at least one additive.
6. 6. The electrolyte composition of claim 5, wherein the at least one additive is selected from the group consisting of fluoroethylene carbonate (FEC), trans-difluoroethylene carbonate (DFEC), ethylene carbonate (VC), ethylene carbonate (VEC), trimethyl phosphite (TMP), tris (trimethylsilyl) phosphite (TMSP), tris (trimethylsilyl) borate, dimethylacetamide, 2-dimethoxy-propane, vinyl acetate, and gamma-butyrolactone (GBL), biphenyl, thiophene, triphenylamine, and 1, 4-benzodioxane-6, 7-diol.
7. 7. The electrolyte composition of claim 1, wherein the electrolyte composition further comprises at least one non-ether solvent.
8. 8. A method of preparing an electrolyte composition, the method comprising: the sodium borohydride, solvent and phenol are combined, thereby forming a solution comprising the solvent and sodium tetra (phenoxy) borate.
9. 9. The method as in claim 8, further comprising: Removing some or all of the solvent from the solution.
10. 10. The method of claim 9, wherein all of the solvent is removed from the solution, thereby yielding dried sodium tetra (phenoxy) borate, the method further comprising: combining a second solvent with the dried sodium tetra (phenoxy) borate, thereby obtaining an electrolyte composition.
11. 11. The method of claim 9, wherein removing some or all of the solvent from the solution comprises heating the solution to evaporate some or all of the solvent, subjecting the solution to a vacuum, or both.
12. 12. A method of preparing an electrolyte composition, the method comprising: The sodium borohydride, solvent and isopropyl alcohol are combined, thereby forming a solution comprising the solvent and sodium tetra (isopropyl) borate.
13. 13. The method as in claim 12, further comprising: Removing some or all of the solvent from the solution.
14. 14. The method of claim 13, wherein all of the solvent is removed from the solution, thereby yielding dried sodium tetra (isopropyl) borate, the method further comprising: The second solvent is combined with the dried sodium tetra (isopropyl) borate, thereby obtaining an electrolyte composition.
15. 15. The method of claim 13, wherein removing some or all of the solvent from the solution comprises heating the solution to evaporate some or all of the solvent, subjecting the solution to a vacuum, or both.

Description

Electrolyte composition for sodium-based battery and method for manufacturing same Background The use of a series of sodium electrolytes based primarily on the salts NaPF 6, naTFSI, naFSI and NaCIO 4 in sodium batteries has been previously investigated. Carbonate electrolytes are generally considered, some of which have been investigated for ether solvents, particularly for sodium metal batteries. Electrolyte performance in sodium cells is related to salt and solvent chemistry. In general, naPF 6 is considered to be currently an advanced technology because its Solid Electrolyte Interface (SEI) formed at sodium metal and sodium-carbon anodes is relatively stable, which can increase Coulombic Efficiency (CE). NaCIO 4, naFSI, and NaTFSI suffer from a stronger reaction (i.e., lower CE) at the anode and less stable SEI. Carbonate electrolytes tend to form stable SEI products to achieve high CE in the later cycles, at the cost of the battery initially consuming more sodium to form these byproducts, reducing battery capacity and initial CE during the early cycles. The ether electrolyte is less reactive at the anode, thereby increasing the initial CE and reducing sodium consumption, however it tends to form less stable SEI products, inhibiting the cell from reaching high CE over longer cycles. Thus, sodium batteries require improved electrolytes. Disclosure of Invention This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary and the foregoing background are not intended to identify key aspects or essential aspects of the claimed subject matter. Furthermore, this summary is not intended to be used as an aid in determining the scope of the claimed subject matter. In some embodiments, electrolyte compositions for use in sodium-based batteries are described. The electrolyte composition includes at least one sodium borate salt having the formula NaB [ OR ] 4、NaBFy[OR]4-y (where y = 1,2, OR 3), naB [ X ] [ OR ] 2、NaB[X]F2, OR NaB [ X ] 2, wherein R in any of the foregoing formulas is selected from the group consisting of alkyl, fluoroalkyl, resonance, fluoro resonance, acetyl, and fluoroacetyl groups, and X in any of the foregoing formulas is selected from the group consisting of glycol groups, fluoro glycol groups, dicarboxylic groups, and fluoro dicarboxylic groups, and at least one ether solvent, fluoroether-based solvent, carbonate-based solvent, OR ionic liquid solvent. In some embodiments, the sodium borate salt may have different R OR X groups, i.e., having the formula NaBF x[ORa]y[ORb]z (where x+y+z=4 and where X, y, z=0 to 3), naB [ OR a][ORb ] [ X ], OR NaB [ X a][Xb ]. In some embodiments, electrolyte compositions for use in sodium-based batteries are described. The electrolyte composition includes at least one sodium borate salt selected from the group consisting of sodium tetra (phenol) borate and sodium tetra (isopropyl) borate, and at least one ether solvent. In some embodiments, a method of forming an electrolyte composition for use in a sodium-based battery is described. The method comprises the step of combining sodium borohydride, a solvent, and an alcohol having the formula ROH, wherein R is selected from the group consisting of alkyl, fluoroalkyl, resonance groups, and fluorine resonance groups. Combining sodium borohydride, solvent and alcohol forms a solution comprising the solvent and a sodium borate salt having the formula NaB (OR) 4. In some embodiments, a method of forming an electrolyte composition for use in a sodium-based battery is described. The method comprises the step of combining sodium borohydride, a solvent, and a ketone having the formula RO, wherein R is selected from the group consisting of alkyl and fluoroalkyl. Combining sodium borohydride, solvent and ketone forms a solution comprising the solvent and a sodium borate salt having the formula NaB (OR) 4. In some embodiments, a method of forming an electrolyte composition for use in a sodium-based battery is described. The method comprises the step of combining sodium borohydride, a solvent, and a carboxylic acid having the formula ROH, wherein R is selected from the group consisting of acetyl and fluoroacetyl. Combining sodium borohydride, solvent, and carboxylic acid forms a solution comprising the solvent and a sodium borate salt having the formula NaB (OR) 4. In some embodiments, a method of forming an electrolyte composition for use in a sodium-based battery is described. The method includes the step of combining sodium borohydride, a solvent, and phenol. Combining sodium borohydride, solvent, and phenol forms a solution comprising solvent and sodium tetra (phenoxy) borate. In some embodiments, a method of forming an electrolyte composition for use in a sodium-based battery is described. The method comprises the step of combining sodium borohydride, a solvent and isopropanol. Combining sodium borohydride, solvent and isopropy