Aluminum secondary battery cathode having oriented graphene

Patent metadata

Field	Value
Publication number	US-10122020-B2
Application number	US-201715450447-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Mar 6, 2017
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

Provided is an aluminum secondary battery comprising an anode, a cathode, a porous separator electronically separating the anode and the cathode, and an electrolyte in ionic contact with the anode and the cathode to support reversible deposition and dissolution of aluminum at the anode, wherein the anode contains aluminum metal or an aluminum metal alloy as an anode active material and the cathode comprises a layer of aligned graphene sheets that are oriented in such a manner that the layer has a graphene edge plane in direct contact with the electrolyte and facing the separator. These aligned/oriented graphene sheets are preferably bonded by a binder for enhanced structural integrity and cycling stability. Such an aluminum battery delivers a high energy density, high power density, and long cycle life.

First claim

We claim:

1. An aluminum secondary battery comprising an anode, a cathode, a porous separator electronically separating said anode and said cathode, and an electrolyte in ionic contact with said anode and said cathode to support reversible deposition and dissolution of aluminum at said anode, wherein said anode contains aluminum metal or an aluminum metal alloy as an anode active material and said cathode comprises a layer of aligned graphene sheets that are oriented in such a manner that said layer has a graphene edge plane in direct contact with said electrolyte and facing said separator.

2. The aluminum secondary battery of claim 1 , wherein said graphene sheets are produced from a thermally exfoliated product selected from the group consisting of meso-phase pitch, meso-phase carbon, meso carbon micro-beads (MCMB), coke particles, expanded graphite flakes, artificial graphite particles, natural graphite particles, highly oriented pyrolytic graphite, soft carbon particles, hard carbon particles, multi-walled carbon nanotubes, carbon nano-fibers, carbon fibers, graphite nano-fibers, graphite fibers, carbonized polymer fibers, and combinations thereof.

3. The aluminum secondary battery of claim 1 , wherein said graphene sheets are bonded together by a binder.

4. The aluminum secondary battery of claim 3 , wherein said binder is chemically cured while the aligned graphene sheets are in a compression state.

5. The aluminum secondary battery of claim 1 , wherein said layer of aligned graphene sheets has a physical density from 0.5 to 1.8 g/cm 3 and has meso-scaled pores having a pore size from 2 nm to 50 nm.

6. The aluminum secondary battery of claim 1 , wherein said layer of aligned graphene sheets has a physical density from 1.1 to 1.8 g/cm 3 and has pores having a pore size from 2 nm to 5 nm.

7. The aluminum secondary battery of claim 1 , wherein said layer of aligned graphene sheets has a specific surface area from 20 m 2 /g to 1,500 m 2 /g.

8. The aluminum secondary battery of claim 1 , further comprising an anode current collector supporting said aluminum metal or aluminum metal alloy or further comprising a cathode current collector supporting said layer of recompressed exfoliated graphite or carbon material.

9. The aluminum secondary battery of claim 8 , wherein said anode current collector contains an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein said filaments have a transverse dimension less than 500 nm.

10. The aluminum secondary battery of claim 9 , wherein said filaments comprise an electrically conductive material selected from the group consisting of electro-spun nano fibers, vapor-grown carbon or graphite nano fibers, carbon or graphite whiskers, carbon nano-tubes, nano-scaled graphene platelets, metal nano wires, and combinations thereof.

11. The aluminum secondary battery of claim 1 , wherein said electrolyte is selected from the group consisting of an aqueous electrolyte, organic electrolyte, molten salt electrolyte, ionic liquid electrolyte, and combinations thereof.

12. The aluminum secondary battery of claim 1 , wherein said electrolyte contains AlF 3 , AlCl 3 , AlBr 3 , AlI 3 , AlF x Cl (3-x) , AlBr x Cl (3-x) , AlI x Cl (3-x) , or a combination thereof, wherein x is from 0.01 to 2.0.

13. The aluminum secondary battery of claim 1 , wherein said electrolyte contains an ionic liquid that contains an aluminum salt mixed with an organic chloride selected from the group consisting of n-butyl-pyridinium-chloride (BuPyCl), 1-methyl-3-ethylimidazolium-chloride (MEICl), 2-dimethyl-3-propylimidazolium-chloride, 1,4-dimethyl-1,2,4-triazolium chloride (DMTC), and mixtures thereof.

14. The aluminum secondary battery of claim 1 , wherein the electrolyte also supports reversible intercalation and de-intercalation of ions at the cathode, wherein said ions include cations, anions, or both.

15. The aluminum secondary battery of claim 1 , wherein said layer of aligned graphene sheets operates as a cathode current collector to collect electrons during a discharge of said aluminum secondary battery and wherein said battery contains no separate or additional cathode current collector.

16. The aluminum secondary battery of claim 1 , wherein said layer of aligned graphene sheets further comprises an electrically conductive binder material which bonds said aligned graphene sheets together to form a cathode electrode layer.

17. The aluminum secondary battery of claim 16 , wherein said electrically conductive binder material comprises a material selected from the group consisting of coal tar pitch, petroleum pitch, meso-phase pitch, a conducting polymer, a polymeric carbon, and derivatives thereof.

18. The aluminum secondary battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.5 volt and a cathode specific capacity greater than 100 mAh/g based on a total cathode active layer weight.

19. The aluminum secondary battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.5 volt and a cathode specific capacity greater than 200 mAh/g based on a total cathode active layer weight.

20. The aluminum secondary battery of claim 1 , wherein said battery has an average discharge voltage no less than 2.0 volts and a cathode specific capacity greater than 100 mAh/g based on a total cathode active layer weight.

21. The aluminum secondary battery of claim 1 , wherein said battery has an average discharge voltage no less than 2.0 volts and a cathode specific capacity greater than 200 mAh/g based on a total cathode active layer weight.

22. A method of manufacturing an aluminum secondary battery, comprising:
(a) providing an anode containing aluminum metal or an aluminum alloy;
(b) providing a cathode containing a layer of aligned graphene sheets; and
(c) providing a porous separator electronically separating said anode and said cathode and an electrolyte capable of supporting reversible deposition and dissolution of aluminum at the anode and reversible adsorption/desorption and/or intercalation/de-intercalation of ions at the cathode;
wherein said layer of aligned graphene sheets is oriented in such a manner that said layer has a graphene edge plane in direct contact with said electrolyte and facing or contacting said separator.

23. The method of claim 22 , further including providing a porous network of electrically conductive nano-filaments to support said aluminum metal or aluminum alloy at the anode.

24. The method of claim 22 , wherein said electrolyte contains an aqueous electrolyte, an organic electrolyte, a molten salt electrolyte, or an ionic liquid.

25. The method of claim 22 , wherein providing a cathode contains subjecting a carbon or graphite material to an expansion treatment selected from an oxidation, fluorination, bromination, chlorination, nitrogenation, intercalation, combined oxidation-intercalation, combined fluorination-intercalation, combined bromination-intercalation, combined chlorination-intercalation, or combined nitrogenation-intercalation, followed by thermal exfoliation at a temperature from 100° C. to 2,500° C. and mechanical shearing.

26. The method of claim 22 , wherein said procedure of providing the cathode includes compressing multiple graphene sheets using a wet compression or dry c

Assignees

• Nanotek Instruments Inc

Inventors

• Su Yu-Sheng
• Zhamu Aruna
• He Hui
• Pan Baofei
• Jang Bor Z

Classifications

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/663

  containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres · CPC title

• C01B2204/32

  Size or surface area · CPC title

• H01M10/054

  Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium · CPC title

• H01M4/043

  involving compressing or compaction · CPC title