Electrolyte for sodium secondary battery and sodium secondary battery using the same

Patent metadata

Field	Value
Publication number	US-10256510-B2
Application number	US-201615041323-A
Country	US
Kind code	B2
Filing date	Feb 11, 2016
Priority date	Feb 13, 2015
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

Provided are an electrolyte for a sodium secondary battery, and a sodium secondary battery using the same, and the sodium secondary battery using the electrolyte for a sodium secondary battery according to the present invention may have an excellent cycle characteristic, charge-discharge capacity, and stability, thereby making it possible to be operated without deterioration at a low temperature for a long time.

First claim

What is claimed is:

1. An electrolyte for a sodium secondary battery comprising:
a sodium molten salt, a first additive represented by Chemical Formula 1, and a second additive represented by Chemical Formula 2, wherein each of the first additive and the second additive has an amount of 0.1 to 30 wt % relative to the total weight of the electrolyte for the sodium secondary battery:
Na x A  [Chemical Formula 1]

NaD  [Chemical Formula 2]

in Chemical Formulas 1 and 2,
A is a sulfur oxide ion, or a nitrate ion,
x is an integer selected from 1 to 4 depending on an ionic valency of A; and
D is selected from NCO—, NCS- or compounds represented by Chemical Formulas 3 to 6,

in Chemical Formulas 3 to 6,
R 1 to R 6 are each independently hydrogen, (C1-C10)alkyl, (C1-C10)alkoxy, (C2-C10)alkenyl, (C2-C10)alkynyl, (C6-C12)aryl, (C3-C12)heteroaryl or (C6-C12)aryl(C1-C10)alkyl;
R 5 and R 6 may be linked to each other to form an alicyclic ring or an aromatic ring;
Z 1 and Z 2 are each independently —CO— or SO 2 —, and
the alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl and arylalkyl of R 1 to R 6 and the alicyclic ring and the aromatic ring of R 5 and R 6 may be further substituted with halogen, amino, nitro or (C1-C10)alkyl.

2. The electrolyte for a sodium secondary battery of claim 1 , wherein A in Chemical Formula 1 is SO 4 2− , SO 3 2− , SO 5 2− , S 2 O 3 2− , S 2 O 4 2− , S 2 O 5 2− , S 2 O 6 2− , S 2 O 7 −2 , S 2 O 8 2− or S 4 O 6 2− .

3. The electrolyte for a sodium secondary battery of claim 1 , wherein the first additive is sodium sulfate, anhydrous sodium sulfate, sodium thiosulfate, sodium metabisulfite, sodium pyrosulfate or sodium nitrate.

4. The electrolyte for a sodium secondary battery of claim 1 , wherein in Chemical Formulas 3 and 4, R 1 to R 6 are each independently hydrogen or (C1-C10)alkyl;
R 5 and R 6 may be linked to each other by (C2-C4)alkenylene to form an aromatic ring;
the alkyl of R 1 to R 6 and the aromatic ring of R 5 and R 6 may be further substituted with halogen, amino, nitro or (C1-C10)alkyl;
Z 1 is CO—; and
Z 2 is —SO 2 —.

5. The electrolyte for a sodium secondary battery of claim 1 , wherein D in Chemical Formula 2 is HCOO—, CH 3 COO—, NCO—, NCS— or Saccharin anion.

6. The electrolyte for a sodium secondary battery of claim 1 , wherein the first additive is Na 2 SO 4 , Na 2 SO 3 , Na 2 S 2 O 3 , Na 2 S 2 O 5 , Na 2 S 2 O 7 or NaNO 3 ; and the second additive is HCOONa, CH 3 COONa, NaOCN, NaSCN or C 7 H 5 O 3 NSNa.

7. The electrolyte for a sodium secondary battery of claim 6 , wherein the second additive has 0.05 to 1.0 mol relative to 1 mol of the first additive.

8. The electrolyte for a sodium secondary battery of claim 1 , wherein when the electrolyte is melted, ionic conductivity is 140 ms/cm or more, and a melting point is 140° C. or less.

9. The electrolyte for a sodium secondary battery of claim 1 , wherein the sodium molten salt is NaAlCl 4 , NaBrCl 4 , NaICl 4 , and mixtures thereof.

10. A sodium secondary battery comprising:
a cathode impregnated with the electrolyte for a sodium secondary battery of claim 1 and including a transition metal;
an anode containing sodium; and
a sodium ion conducting solid electrolyte provided between the cathode and the anode.

Assignees

• Sk Innovation Co Ltd

Inventors

• Park Dai In
• Lee Seung Ok
• Kim Jeong Soo
• Lee Hyung Keun

Classifications

• H01M2300/0048

  Molten electrolytes used at high temperature · CPC title

• H01M10/39

  working at high temperature · CPC title

• H01M2300/002

  Inorganic electrolyte · CPC title

• H01M10/399 Primary

  Cells with molten salts · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title