Lithium anode-protecting polymer layer for a lithium metal secondary battery and manufacturing method

Patent metadata

Field	Value
Publication number	US-10862129-B2
Application number	US-201715485934-A
Country	US
Kind code	B2
Filing date	Apr 12, 2017
Priority date	Apr 12, 2017
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

Provided is lithium secondary battery comprising a cathode, an anode, and an electrolyte or separator-electrolyte assembly disposed between the cathode and the anode, wherein the anode comprises: (a) a foil or coating of lithium or lithium alloy; and (b) a thin layer of a high-elasticity polymer disposed between the foil/coating and the electrolyte (or separator-electrolyte assembly), having a recoverable tensile strain no less than 2%, a lithium ion conductivity no less than 10−6 S/cm at room temperature, and a thickness from 1 nm to 10 μm, wherein the high-elasticity polymer contains a cross-linked network of polymer chains having an ether linkage, nitrile-derived linkage, benzo peroxide-derived linkage, ethylene oxide linkage, propylene oxide linkage, vinyl alcohol linkage, cyano-resin linkage, triacrylate monomer-derived linkage, tetraacrylate monomer-derived linkage, or a combination thereof in the cross-linked network of polymer chains.

First claim

We claim:

1. A lithium secondary battery comprising a cathode, an anode, and an electrolyte or separator-electrolyte assembly disposed between said cathode and said anode, wherein said anode comprises:
a) a foil or coating of lithium or lithium alloy as an anode active material; and
b) a layer of a polymer having a recoverable tensile strain from 2% to 700%, a lithium ion conductivity no less than 10 −6 S/cm at room temperature, and a thickness from 1 nm to 10 μm, wherein said layer of said polymer is disposed between said foil or coating of lithium or lithium alloy and said electrolyte or separator-electrolyte assembly.

2. The lithium secondary battery of claim 1 , wherein said polymer contains a cross-linked network of polymer chains having an ether linkage, nitrile-derived linkage, benzo peroxide-derived linkage, ethylene oxide linkage, propylene oxide linkage, vinyl alcohol linkage, cyano-resin linkage, triacrylate monomer-derived linkage, tetraacrylate monomer-derived linkage, and combinations thereof in said cross-linked network of polymer chains.

3. The lithium secondary battery of claim 1 , wherein said polymer contains a cross-linked network of polymer chains selected from nitrile-containing polyvinyl alcohol chains, cyanoresin chains, pentaerythritol tetraacrylate chains, pentaerythritol triacrylate chains, ethoxylated trimethylolpropane triacrylate (ETPTA) chains, ethylene glycol methyl ether acrylate (EGMEA) chains, and combinations thereof.

4. The lithium secondary battery of claim 1 , wherein said polymer contains from 0.1% to 50% by weight of a lithium ion-conducting additive dispersed therein, or contains therein from 0.1% by weight to 10% by weight of a reinforcement nano filament selected from carbon nanotube, carbon nano-fiber, graphene, and combinations thereof.

5. The lithium secondary battery of claim 1 , wherein said polymer is mixed with a lithium ion-conducting additive to form a composite wherein said lithium ion-conducting additive is dispersed in said polymer and is selected from Li 2 CO 3 , Li 2 O, Li 2 C 2 O 4 , LiOH, LiX, ROCO 2 Li, HCOLi, ROLi, (ROCO 2 Li) 2 , (CH 2 OCO 2 Li) 2 , Li 2 S, Li X SO y , and combinations thereof, wherein X=F, Cl, I, or Br, R=a hydrocarbon group, 0≤x≤1, 1≤y≤4.

6. The lithium secondary battery of claim 1 , wherein said high elasticity polymer further contains an electrically conducting material dispersed therein and said electrically conducting material is selected from an electron-conducting polymer, a metal particle or wire, a graphene sheet, a carbon fiber, a graphite fiber, a carbon nano-fiber, a graphite nano-fiber, a carbon nanotube, a graphite particle, an expanded graphite flake, an acetylene black particle, and combinations thereof.

7. The lithium secondary battery of claim 6 , wherein said electrically conducting material has a thickness or diameter less than 100 nm.

8. The lithium secondary battery of claim 1 , wherein said polymer further contains a lithium salt dispersed therein and said lithium salt is selected from lithium perchlorate, LiClO 4 , lithium hexafluorophosphate, LiPF 6 , lithium borofluoride, LiBF 4 , lithium hexafluoroarsenide, LiAsF 6 , lithium trifluoro-metasulfonate, LiCF 3 SO 3 , bis-trifluoromethyl sulfonylimide lithium, LiN(CF 3 SO 2 ) 2 , lithium bis(oxalato)borate, LiBOB, lithium oxalyldifluoroborate, LiBF 2 C 2 O 4 , lithium oxalyldifluoroborate, LiBF 2 C 2 O 4 , lithium nitrate, LiNO 3 , Li-Fluoroalkyl-Phosphates, LiPF 3 (CF 2 CF 3 ) 3 , lithium bisperfluoro-ethysulfonylimide, LiBETI, lithium bis(trifluoromethanesulphonyl)imide, lithium bis(fluorosulphonyl)imide, lithium trifluoromethanesulfonimide, LiTFSI, an ionic liquid-based lithium salt, and combinations thereof.

9. The lithium secondary battery of claim 1 , wherein said polymer is mixed with an electron-conducting polymer selected from polyaniline, polypyrrole, polythiophene, polyfuran, a bi-cyclic polymer, a sulfonated derivative thereof, and combinations thereof.

10. The lithium secondary battery of claim 1 , wherein the polymer forms a mixture or blend with a lithium ion-conducting polymer selected from poly(ethylene oxide) (PEO), Polypropylene oxide (PPO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVdF), Poly bis-methoxy ethoxyethoxide-phosphazenex, Polyvinyl chloride, Polydimethylsiloxane, poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP), a sulfonated derivative thereof, and combinations thereof.

11. The lithium secondary battery of claim 1 , wherein said layer of polymer has a thickness from 1 nm to 1 μm.

12. The lithium secondary battery of claim 1 , wherein said layer of polymer has a thickness less than 100 nm.

13. The lithium secondary battery of claim 1 , wherein said layer of polymer has a thickness less than 10 nm.

14. The lithium secondary battery of claim 1 , wherein said polymer has a lithium ion conductivity from 10 −4 S/cm to 10 −2 S/cm.

15. The lithium secondary battery of claim 1 , wherein said cathode active material is selected from an inorganic material, an organic material, a polymeric material, and combinations thereof, and said inorganic material does not include sulfur or alkali metal polysulfide.

16. The lithium secondary battery of claim 15 , wherein said inorganic material is selected from a metal oxide, metal phosphate, metal silicide, metal selenide, transition metal sulfide, and combinations thereof.

17. The lithium secondary battery of claim 16 , wherein said metal oxide contains a vanadium oxide selected from the group consisting of VO 2 , Li x VO 2 , V 2 O 5 , Li x V 2 O 5 , V 3 O 8 , Li x V 3 O 8 , Li x V 3 O 7 , V 4 O 9 , Li x V 4 O 9 , V 6 O 13 , Li x V 6 O 13 , their doped versions, their derivatives, and combinations thereof, wherein 0.1<x<5.

18. The lithium secondary battery of claim 16 , wherein said metal oxide or metal phosphate is selected from a layered compound LiMO 2 , spinel compound LiM 2 O 4 , olivine compound LiMPO 4 , silicate compound Li 2 MSiO 4 , Tavorite compound LiMPO 4 F, borate compound LiMBO 3 , and combinations thereof, wherein M is a transition metal or a mixture of multiple transition metals.

19. The lithium secondary battery of claim 16 , wherein said inorganic material is selected from: (a) bismuth selenide or bismuth telluride, (b) transition metal dichalcogenide or trichalcogenide, (c) sulfide, selenide, or telluride of niobium, zirconium, molybdenum, hafnium, tantalum, tungsten, titanium, cobalt, manganese, iron, nickel, or a transition metal; (d) boron nitride, and (e) combinations thereof.

20. The lithium secondary battery of claim 15 , wherein said inorganic material is selected from a lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium vanadium oxide, lithium-mixed metal oxide, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium mixed metal phosphate, lithium metal silicide, and combinations thereof.

21. The lithium secondary battery of claim 15 , wherein said inorganic material is selected from a metal fluoride or metal chloride including the group consisting of CoF 3 , MnF 3 , FeF 3 , VF 3 , VOF 3 , TiF 3 , BiF 3 , NiF 2 , FeF 2 , CuF 2 , CuF, SnF 2 , AgF, CuCl 2 , FeCl 3 , MnCl 2 , and combinations thereof.

22. The lithium secondary battery of claim 15 , wherein said inorganic material is selected from a lithium transition metal silicate, denoted as Li 2 MSiO 4 or Li 2 Ma x Mb y SiO 4 , wherein M and Ma are selected from Fe, Mn, Co, Ni, V, or VO; Mb is

Assignees

• Nanotek Instruments Inc
• Global Graphene Group Inc

Inventors

• Pan Baofei
• He Hui
• Zhamu Aruna
• Jang Bor Z

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/628 Primary

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/5815

  Sulfides · CPC title