Electrolyte for sodium secondary battery and sodium secondary battery using thereof

Patent metadata

Field	Value
Publication number	US-10218034-B2
Application number	US-201514923020-A
Country	US
Kind code	B2
Filing date	Oct 26, 2015
Priority date	Oct 28, 2014
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

Provided are an electrolyte for a sodium secondary battery and a sodium secondary battery using the same. More particularly, the sodium secondary battery includes an anode containing sodium, a cathode containing a transition metal, and a sodium ion conductive solid electrolyte provided between the anode and the cathode, wherein the cathode is impregnated in an electrolyte containing a molten sodium salt and an electrolyte additive, the electrolyte additive including an inorganic sodium salt.

First claim

What is claimed is:

1. A sodium secondary battery having an operation temperature of 120° C. to 200° C. and comprising:
a cathode containing a transition metal, and impregnated in an electrolyte having a melting point of 150° C. or less and comprising a molten sodium salt and an electrolyte additive made of an inorganic sodium salt represented by the following Chemical Formula:
Na x A

wherein A is at least one anion selected from the group consisting of S a O b 2− (1≤a<4, 1<b<9), a nitrate ion (NO 3 − ), and a combination thereof, and
x is an integer of 1 to selected depending on an ionic valence of A which is a counter ion;
an anode containing sodium; and
a sodium ion conductive solid electrolyte provided between the cathode and the anode.

2. The sodium secondary battery of claim 1 , wherein A is one or more anions selected from the group consisting of a sulfate ion, which is any one selected from SO 4 2− , SO 3 2− , S 2 O 3 2− , S 2 O 5 2− , and S 2 O 7 2− , the nitrate ion (NO 3 − ), and the combination thereof.

3. The sodium secondary battery of claim 2 , wherein Na x A is one or more selected from the group consisting of sodium sulfate (Na 2 SO 4 ), anhydrous sodium sulfate (Na 2 SO 3 ), sodium thiosulfate (Na 2 S 2 O 3 ), sodium metabisulfite (Na 2 S 2 O 5 ), sodium pyrosulfate (Na 2 S 2 O 7 ), sodium nitrate (NaNO 3 ), and a combination thereof.

4. The sodium secondary battery of claim 1 , wherein the electrolyte contains 0.1 to 20 wt % of the electrolyte additive.

5. The sodium secondary battery of claim 1 , wherein the electrolyte has ion conductivity of 200 ms/cm or more at the time of being melted.

6. The sodium secondary battery of claim 1 , wherein the anode contains molten sodium.

7. The sodium secondary battery of claim 1 , wherein the cathode contains one or more metals selected from nickel (Ni), copper (Cu), iron (Fe), manganese (Mn), cobalt (Co), and an alloy thereof.

Assignees

• Sk Innovation Co Ltd
• Ulsan Nat Inst Science & Tech Unist
• Unist Ulsan National Institute Science And Tech

Inventors

• Lee Seung Ok
• Koh Won Sang
• Kim Jeong Soo
• Park Dai In
• Chae Je Hyun
• Choi Nam Soon
• Jang Jun Yeong

Classifications

• H01M4/38

  of elements or alloys · CPC title

• H01M2300/0088

  Composites · CPC title

• H01M2300/0048

  Molten electrolytes used at high temperature · CPC title

• H01M10/399 Primary

  Cells with molten salts · CPC title

• H01M2300/0062

  Nitrates · CPC title