Lithium-ion cell having a high-capacity cathode

Patent metadata

Field	Value
Publication number	US-10236500-B2
Application number	US-201715491710-A
Country	US
Kind code	B2
Filing date	Apr 19, 2017
Priority date	Apr 12, 2012
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A method of operating a lithium-ion cell comprising (a) a cathode comprising a carbon or graphitic material having a surface area to capture and store lithium thereon; (b) an anode comprising an anode active material; (c) a porous separator disposed between the two electrodes; (d) an electrolyte in ionic contact with the two electrodes; and (e) a lithium source disposed in at least one of the two electrodes to obtain an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made; wherein the method comprises: (A) electrochemically forming the cell from the OCV to either a first lower voltage limit (LVL) or a first upper voltage limit (UVL), wherein the first LVL is no lower than 0.1 volts and the first UVL is no higher than 4.6 volts; and (B) cycling the cell between a second LVL and a second UVL.

First claim

We claim:

1. A surface mediated lithium-ion cell comprising (a) a cathode consisting essentially of a carbon material as a cathode active material having a surface area to capture and store lithium thereon, wherein said carbon in the cathode is selected from graphite worms, chemically treated graphite with an inter-planar separation no less than 0.4 nm, chemically expanded soft carbon, chemically expanded hard carbon, chemically expanded multi-walled carbon nanotube, chemically expanded carbon nanofiber, and a combination thereof as the only cathode active material, wherein said cathode may optionally contain a conductive filler and/or an optional binder, and wherein said cathode forms a meso-porous structure having a pore size in the range from 2 nm to 50 nm and a specific surface area greater than 50 m 2 /g; (b) an anode comprising an anode active material; (c) a porous separator disposed between the anode and the cathode; and (d) a lithium-containing electrolyte in ionic contact with the anode and the cathode; wherein said surface area of said cathode active material, greater than 50 m 2 /gram, is in direct contact with said lithium-containing electrolyte; and e) a lithium source disposed on at least one of the two electrodes to obtain an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made; wherein the anode active material is selected from the group consisting of:
(i) non-lithiated silicon (Si), germanium (Ge), tin (Sn), and mixtures thereof;
(ii) non-lithiated alloys or intermetallic compounds of Si, Ge, Sn, and their mixtures;
(iii) non-lithiated oxides, carbides, nitrides, sulfides, phosphides, selenides, tellurides, or antimonides of Si, Ge, Sn, Sb, Bi, Al, Fe, Ti, Co, Ni, Mn, Cd, and mixtures or composites thereof; and
(iv) non-lithiated salts or hydroxides of Sn;

wherein said surface mediated lithium-ion cell has an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made and the cell is then electrochemically formed by operating the cell from said OCV to a lower voltage limit (LVL) lower than said OCV or to a upper voltage limit (UVL) higher than said OCV after the cell is made; and wherein said LVL is no lower than 0.1 volts and said UVL is no higher than 4.6 volts.

2. The lithium-ion cell of claim 1 , wherein said surface mediated lithium-ion cell is subsequently charged to a voltage no higher than said UVL and discharged to a voltage no lower than said LVL.

3. The lithium-ion cell of claim 1 , wherein said cathode active material exhibits a specific capacity greater than 500 mAh/g.

4. The lithium-ion cell of claim 1 , wherein said cathode active material exhibits a specific capacity greater than 1,000 mAh/g.

5. The lithium-ion cell of claim 1 , wherein said cathode active material exhibits a specific capacity greater than 2,000 mAh/g.

6. The surface mediated lithium-ion cell claim 1 , wherein said anode active material has a lithium-storing capacity no less than 400 mAh/g.

7. The surface mediated lithium-ion cell claim 1 , wherein said anode active material is mixed with a conductive additive and/or a resin binder to form a porous electrode structure, or coated onto a current collector in a coating or thin film form.

8. The surface mediated lithium-ion cell claim 1 , wherein said cathode has a specific surface area greater than 100 m 2 /g.

9. The surface mediated lithium-ion cell claim 1 , wherein said cathode has a specific surface area greater than 1000 m 2 /g.

10. The surface mediated lithium-ion cell claim 1 , wherein the lithium source comprises a lithium chip, lithium alloy chip, lithium foil, lithium alloy foil, lithium powder, lithium alloy powder, surface stabilized lithium particles, a mixture of lithium metal or lithium alloy with a lithium intercalation compound, lithium or lithium alloy film coated on a surface of an anode or cathode active material, or a combination thereof.

11. The surface mediated lithium-ion cell of claim 1 , wherein said anode active material contains a mixture of a high capacity anode material and a high rate capable anode material, wherein said high rate capable anode material is selected from nano-scaled particles or filaments of a transition metal oxide, CO 3 O 4 , Mn 3 O 4 , Fe 3 O 4 , or a combination thereof, and said high capacity anode material is selected from Si, Ge, Sn, SnO, or a combination thereof.

12. The lithium-ion cell of claim 1 , further comprising an anode current collector and/or a cathode current collector that is stainless steel, a surface-passivated metal, or a coated metal.

13. The lithium-ion cell of claim 1 , wherein said anode, said cathode, or both contains less than 1% by weight oxygen.

14. A lithium-ion cell comprising (a) a cathode consisting essentially of a carbon material as a cathode active material having a surface area to capture and store lithium thereon, wherein said cathode forms a meso-porous structure having a pore size in the range from 2 nm to 50 nm and a specific surface area greater than 50 m 2 /g; (b) an anode comprising a pre-lithiated anode active material; (c) a porous separator disposed between the anode and the cathode; and (d) a lithium-containing electrolyte in ionic contact with the anode and the cathode, wherein said surface area of said cathode active material, being greater than 50 m 2 /g, is in direct contact with said lithium-containing electrolyte; wherein said cell has an open circuit voltage (OCV) from 0.5 volts to 2.8 volts when the cell is made, wherein said carbon material in the cathode is selected from graphite worms, chemically treated graphite with an inter-graphene planar separation no less than 0.4 nm, chemically expanded soft carbon, chemically expanded hard carbon, chemically expanded multi-walled carbon nanotube, chemically expanded carbon nanofiber, or a combination thereof as the only cathode active material having a surface area to capture and store lithium thereon, wherein said cathode may also optionally contain a conductive filler and/or an optional binder and wherein said pre-lithiated anode active material is a nanoparticle, nanodisc, nanoplatelet, nanowire, nanorod, nanobelt, nanoscroll, nanotube, nanofilament, nanocoating, or nanofilm selected from:
(i) a pre-lithiated silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), cadmium (Cd), or a mixture thereof;
(ii) a pre-lithiated alloy or intermetallic compound of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Co, Ni, Mn, Cd, or a mixture thereof;
(iii) a pre-lithiated oxide, carbide, nitride, sulfide, phosphide, selenide, telluride, or antimonide of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, Ti, Co, Ni, Mn, Cd, or a mixture or composite thereof,
(iv) a pre-lithiated salt or hydroxide of Sn; or
(v) a pre-lithiated carbon or graphite material,

and wherein said anode active material is electrically connected directly to an anode current collector or is connected to an anode current collector through a binder and/or a conductive additive and wherein said cell has a maximum energy density no less than 100 Wh/kg and a maximum power density no less than 1,000 W/kg.

15. The surface mediated lithium-ion cell of claim 14 , wherein said anode active material contains a mixture of a high capacity anode material and a high rate capable anode material, wherein said high rate capable anode material is selected from nano-scaled particles or filaments of a lithium transition metal oxide, lithiated Co 3 O 4 , lithiated Mn 3 O 4 , lithiated Fe 3 O 4 , Li 4 Ti 5 O 12 , or a combination thereof, and wherein said high

Assignees

• Nanotek Instruments Inc

Inventors

• Zhamu Aruna
• Jang Bor Z

Classifications

• H01G11/50

  specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title

• H01M4/0445

  Forming after manufacture of the electrode, e.g. first charge, cycling · CPC title