Thin and flexible solid electrolyte for lithium-ion batteries

Patent metadata

Field	Value
Publication number	US-10122002-B2
Application number	US-201514601355-A
Country	US
Kind code	B2
Filing date	Jan 21, 2015
Priority date	Jan 21, 2015
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A lithium-ion conducting, solid electrolyte is deposited on a thin, flexible, porous alumina membrane which is placed between co-extensive facing side surfaces of a porous, lithium-accepting, negative electrode and a positive electrode formed of a porous layer of particles of a compound of lithium, a transition metal element, and optionally, another metal element. A liquid electrolyte formed, for example, of LiPF6 dissolved in an organic solvent, infiltrates the electrode materials of the two porous electrodes for transport of lithium ions during cell operation. But the solid electrolyte permits the passage of only lithium ions, and the negative electrode is protected from damage by transition metal ions or other chemical species produced in the positive electrode of the lithium-ion cell.

First claim

The invention claimed is:

1. A lithium-ion cell comprising:
a negative electrode comprising a porous layer of particles of a composition into which lithium can be inserted from a lithium-ion containing electrolyte, the porous layer of negative electrode particles having a thickness and a two-dimensional shape with opposing sides, one side of the porous layer of negative electrode particles being bonded to a surface of a current collector, the pores of the layer of negative electrode particles being infiltrated with a non-aqueous liquid, lithium ion-containing electrolyte such that lithium ions are transported through the liquid electrolyte into and out of the negative electrode particles during charging and discharging of the lithium-ion cell;
a positive electrode comprising a porous layer of particles of a compound comprising lithium and a transition metal, the porous layer of the positive electrode compound having a thickness and a two-dimensional shape with opposing sides, the two dimensional shape being coextensive with the two-dimensional shape of the porous layer of negative electrode particles, one side of the porous layer of positive electrode particles being bonded to a surface of a current collector, the pores of the layer of positive electrode compound particles being infiltrated with a non-aqueous liquid, lithium ion-containing electrolyte such that lithium ions and transition metal ions are transported into the liquid electrolyte during discharging and charging of the lithium-ion cell;
a flexible membrane formed of a lithium-containing ceramic composition and having a thickness and a two dimensional shape with opposing sides, the membrane having individual transverse pores extending from one side of the membrane to the other side, the two dimensional shape of the membrane being coextensive with the second side of each of the negative electrode and the positive electrode, the membrane having a coating of a solid electrolyte composition that permits the passage of lithium ions from one side of the porous membrane through the pores of the membrane to the other side of the membrane, but does not permit the passage of transition metal ions through the solid electrolyte, wherein the coating of the solid electrolyte composition comprises one of (1) an oxide of lithium and at least one other metal, (2) a sulfide of lithium and a sulfide of silicon, and (3) a carbon-based polymer filled with particles of lithium salt; and
the second side of the negative electrode being placed against one side of the porous membrane and the second side of the positive electrode being placed against the other side of the porous membrane, such that, in the operation of the lithium-ion cell, transition metal ions are not permitted to flow through the solid electrolyte and through the pores of the membrane to reach the negative electrode particles in the negative electrode.

2. A lithium-ion cell as stated in claim 1 in which the negative electrode material comprises one or more of graphite, a mixture of graphite and silicon, TiO 2 , and Li 4 Ti 5 O 12 .

3. A lithium-ion cell as stated in claim 1 in which the negative electrode material comprises a mixture or alloy of one or more of Sn, Si, SiO 2 , Cr, Mn, Fe, Co, Ni, and Cu.

4. A lithium-ion cell as stated in claim 1 in which the positive electrode material comprises a porous layer of particles of an oxide, phosphate, sulfate, sulfide, or fluoride compound that comprises lithium, a transition metal element, and at least one other element.

5. A lithium-ion cell as stated in claim 1 in which the positive electrode material comprises an oxide of lithium, nickel, and manganese or a combination of oxides of lithium, cobalt, nickel, and manganese.

6. A lithium-ion cell as stated in claim 1 in which the positive electrode material comprises at least one of (i) Li 1+x Ni y Co z Mn 1−x−y−z O 2 where x, y, and z have values such that the ratios of Ni—Co—Mn are one of 1-1-1, ⅓-⅓-⅓, 5-3-2, 6-2-2, 8-1-1, and 9-½-½, (ii) LiNi 0.5 Mn 1.5 O 4 , and (iii) LiNi 1−x MxO 2 , where 0≤x≤0.5 and M is one or more of Al, Ti, Cr, Mn, Fe, Co, Cu, Zn, Mn.

7. A lithium-ion cell as stated in claim 1 in which a coating of the solid electrolyte is applied to one surface of the flexible membrane such that it covers all of the pore openings on that side of the membrane, and the second side of the positive electrode is placed against the coating of the solid electrolyte.

8. A lithium-ion cell as stated in claim 1 in which the each of the pores of the membrane are closed to the flow of the liquid electrolyte by a deposit of solid electrolyte material within the pores of the membrane.

9. A lithium-ion cell as stated in claim 1 in which the membrane has a uniform thickness in the range of ten nanometers to one millimeter and the pores have diameters up to fifty micrometers and the pores are distributed generally uniformly over the sides of the membrane.

10. A lithium-ion cell as stated in claim 9 in which the total area of the pore openings is about 20% to 95% of the apparent area of the two-dimensional shape of the membrane.

11. A lithium-ion cell as stated in claim 1 in which the coating of the solid electrolyte comprises the oxide of lithium and at least one other metal, the other metal being selected from the group consisting of lanthanum, titanium, zirconium, niobium, tantalum, germanium, aluminum, and gallium.

12. A lithium-ion cell as stated in claim 11 in which the coating of the solid electrolyte comprises an oxide of lithium, and at least one other metal, and one or more of phosphorus, silicon, and sodium.

13. A lithium-ion cell as stated in claim 1 in which the lithium salt is selected from the group consisting of lithium hexafluorophosphate LiPF6, lithium perchlorate LiClO4, lithium tetrafluoro-borate LiBF4, lithium hexafluoroarsenate LiAsF6, lithium tetrachloroaluminate LiAlCU, lithium trifluoromethane sulfonate LiCF3SO3, lithium bis(trifluoromethane sulfonyl) imide (lithium imide) LiN(CF3SO2)2, lithium methide LiC(SO2CF3)3, lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) Li3N(SO2CF3)2, lithium bis(fluorosulfonyl) imide (LiFSI) LiN(SO2F)2, lithium bis(oxalato) borate (LiBOB), LiB(C2O4)2, lithium difluoro(oxalato) borate (LiFOB) LiBF2C2O4.

14. A lithium-ion cell as stated in claim 1 in which the carbon-based polymer is selected from the group consisting of polyethylene oxide (PEO), PEO-based copolymers including alternating copolymer, block copolymer, or a homogeneous blend of at least two polymers including polystyrene, polyester, polypropylene, polyethylene napthalate, polycarbonate, polyphenylene sulfide, polytetrafluoroethylene (PTFE), polyimide, poly(acrylonitrile), poly(methyl methacrylate), and poly(vinylidene fluoride) (PVDF).

15. A lithium-ion cell comprising:
a negative electrode comprising a porous layer of particles of a composition comprising one or more of graphite, a lithium-accepting mixture of graphite with another element, and a lithium-accepting oxide of titanium or of titanium and lithium, the porous layer of negative electrode particles having a thickness and a two-dimensional shape with opposing sides, one side of the porous layer of negative electrode particles being bonded to a surface of a current collector, the pores of the layer of negative electrode particles being infiltrated with a non-aqueous liquid, lithium ion-containing electrolyte such that lithium ions are transported through the liquid electrolyte into and out of the negative electrode particles during charging and discharging of the lithium-ion cell;
a positive electrode comprising a porous layer of particles of an oxide o

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kim Jung Hyun
• Powell Jr Bob R
• Jiang Meng
• Lu Peng
• Xiao Xingcheng
• Pieczonka Nicholas P W

Classifications

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M50/434

  Ceramics · CPC title

• H01M50/491

  Porosity · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title

• H01M50/449

  having a layered structure · CPC title