Positive electrode for metal air battery, metal air battery including the same, and method of preparing the positive electrode for metal air battery

Patent metadata

Field	Value
Publication number	US-10593950-B2
Application number	US-201715667753-A
Country	US
Kind code	B2
Filing date	Aug 3, 2017
Priority date	Aug 8, 2016
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A positive electrode for a lithium battery includes a lithium salt, a carbonaceous material, and a coating on a surface of the carbonaceous material, the coating including a polymer electrolyte including a hydrophilic material and a hydrophobic material, wherein a portion of the polymer electrolyte is anchored to the surface of the carbonaceous material by a chemical bond.

First claim

What is claimed is:

1. A positive electrode for a metal air battery, the positive electrode comprising:
a lithium salt;
a carbonaceous material; and
a coating on a surface of the carbonaceous material, the coating comprising a polymer electrolyte comprising a hydrophilic material and a hydrophobic material,
wherein a portion of the polymer electrolyte is anchored to the surface of the carbonaceous material by a chemical bond, and
wherein the polymer electrolyte comprises a block copolymer comprising a hydrophobic block comprising the hydrophobic material and a hydrophilic block comprising the hydrophilic material, and
wherein the hydrophilic block is a polymer block having a lithium ion conductive group as a side chain and the polymer block having a lithium ion conductive group as a side chain is a polyacrylate block functionalized with —(CF 3 SO 2 ) 2 N − , or —(FSO 2 ) 2 N − , or a polymethacrylate block functionalized with —(CF 3 SO 2 ) 2 N − or —(FSO 2 ) 2 N − —.

2. The positive electrode of claim 1 , wherein
a difference between a contact angle with water of the hydrophilic material and a contact angle with water of the hydrophobic material is 5° or greater.

3. The positive electrode of claim 2 , wherein the contact angle with water of the hydrophilic material is about 0° to 70°.

4. The positive electrode of claim 2 , wherein the contact angle with water of the hydrophobic material is 70° or greater.

5. The positive electrode of claim 1 , wherein all or a portion of the hydrophobic material of the polymer electrolyte is anchored to the surface of the carbonaceous material via a noncovalent bond.

6. The positive electrode of claim 1 , wherein all or a portion of the hydrophobic material of the polymer electrolyte is adsorbed to the surface of the carbonaceous material via a Van der Waals' interaction.

7. The positive electrode of claim 1 , wherein the polymer electrolyte comprises a crosslinked polymer electrolyte.

8. The positive electrode of claim 1 , wherein the hydrophobic block of the block copolymer is anchored to the surface of the carbonaceous material, and the hydrophilic block is disposed on the surface of and separated from the carbonaceous material.

9. The positive electrode of claim 1 , wherein the block copolymer comprises at least two different monomer blocks.

10. The positive electrode of claim 1 , wherein the hydrophilic block of the block copolymer has a number average molecular weight of about 500 Daltons to about 20,000 Daltons.

11. The positive electrode of claim 1 , wherein the block copolymer comprises a polyethylene glycol-b-polypropylene glycol diblock copolymer, a polyethylene oxide-b-polypropylene oxide diblock copolymer, a polystyrene-b-polyethylene glycol diblock copolymer, a polystyrene-b-polyethylene oxide diblock copolymer, a polystyrene-b-poly(4-vinylpyridine) diblock copolymer, a polystyrene-b-poly(meth)acrylate diblock copolymer, a polystyrene-b-poly(meth)acrylate diblock copolymer functionalized with TFSI − anion, a polystyrene-b-poly(meth)acrylate diblock copolymer functionalized with FSI − anion, a polyethylene glycol-b-polypropylene glycol-b-polyethylene glycol triblock copolymer, a polyethylene oxide-b-polypropylene oxide-b-polyethylene oxide triblock copolymer, a polyethylene glycol-b-polystyrene-b-polyethylene glycol triblock copolymer, a polyethylene oxide-b-polystyrene-b-polyethylene oxide triblock copolymer, or a combination thereof.

12. The positive electrode of claim 1 , wherein the block copolymer comprises a crosslinked polyethylene glycol-b-polypropylene glycol diblock copolymer, a crosslinked polyethylene oxide-b-polypropylene oxide diblock copolymer, a crosslinked polystyrene-b-polyethylene glycol diblock copolymer, a crosslinked polystyrene-b-polyethylene oxide diblock copolymer, a crosslinked polystyrene-b-poly(meth)acrylate diblock copolymer functionalized with TFSI − anion, a crosslinked polystyrene-b-poly(meth)acrylate diblock copolymer functionalized with FSI − anion, a crosslinked polyethylene glycol-b-polypropylene glycol-b-polyethylene glycol triblock copolymer, a crosslinked polyethylene oxide-b-polypropylene oxide-b-polyethylene oxide triblock copolymer, a crosslinked polyethylene glycol-b-polystyrene-b-polyethylene glycol triblock copolymer, a crosslinked polyethylene oxide-b-polystyrene-b-polyethylene oxide triblock copolymer, or a combination thereof.

13. The positive electrode of claim 1 , wherein the block copolymer has a number average molecular weight of about 3,000 Daltons to about 60,000 Daltons.

14. The positive electrode of claim 1 , wherein an amount of the polymer electrolyte is about 10 parts by weight to about 300 parts by weight based on 100 parts by weight of the carbonaceous material.

15. The positive electrode of claim 1 , wherein the polymer electrolyte layer has thickness of about 1 nanometer to about 30 nanometers.

16. The positive electrode of claim 1 , wherein the polymer electrolyte layer is electrochemically stable with respect to lithium in a charge/discharge voltage range of about 1.4 volts to about 4.5 volts.

17. The positive electrode of claim 1 , wherein the carbonaceous material comprises a porous carbon structure.

18. The positive electrode of claim 1 , wherein the carbonaceous material comprises carbon nanotubes, carbon nanoparticles, carbon nanofibers, carbon nanosheets, carbon nanorods, carbon nanobelts, graphene, graphene oxide, carbon aerogel, inverse opal carbon, or a combination thereof.

19. The positive electrode of claim 1 , wherein an amount of the carbonaceous material is about 50 parts by weight to about 80 parts by weight based on 100 parts by weight of the positive electrode.

20. The positive electrode of claim 1 , wherein the lithium salt comprises LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiN(SO 2 C 2 F 5 ) 2 , Li(CF 3 SO 2 ) 2 N, LiC 4 F 9 SO 3 , LiClO 4 , LiAlO 2 , LiAlCl 4 , LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 )(where x and y are natural numbers), LiF, LiBr, LiCl, LiOH, LiI, LiB(C 2 O 4 ) 2 , or a combination thereof.

21. The positive electrode of claim 1 , wherein an amount of the lithium salt is about 5 parts by weight to about 60 parts by weight based on 100 parts by weight of the positive electrode.

22. The positive electrode of claim 1 , wherein the positive electrode is an air electrode.

23. A metal air battery comprising:
a negative electrode comprising lithium or a lithium alloy;
the positive electrode according to claim 1 ; and
a separator disposed between the negative electrode and the positive electrode.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Hyunpyo
• Kim Taeyoung
• Lee Dongjoon
• Lee Heungchan
• Im Dongmin
• Choi Wonsung

Classifications

• H01M4/625 Primary

  Carbon or graphite · CPC title

• H01M4/8657 Primary

  layered · CPC title

• H01M12/08

  composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/8652

  as mixture · CPC title