Solid-state nanofiber polymer multilayer composite electrolytes and cells

Patent metadata

Field	Value
Publication number	US-2023102140-A1
Application number	US-202117490956-A
Country	US
Kind code	A1
Filing date	Sep 30, 2021
Priority date	Sep 30, 2021
Publication date	Mar 30, 2023
Grant date	—

Abstract

A solid-state electrolyte for a multilayer solid-state electrochemical cell is described herein. The electrolyte comprises a lithium electrolyte salt and nanofibers of a cubic phase lithium lanthanum zirconium oxide (c-LLZO), and a polymer interspersed with the nanofibers and electrolyte salt. Electrochemical cells comprising the solid-state electrolyte, and solid-state cathodes comprising the nanofibers of c-LLZO are also described herein.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1 . A solid-state electrolyte for a multilayer solid-state electrochemical cell; the electrolyte comprising: a lithium electrolyte salt, at least about 55 wt % nanofibers of a cubic phase lithium lanthanum zirconium oxide (c-LLZO), and a polymer interspersed with the nanofibers and electrolyte salt; wherein the nanofibers are interconnected in a three-dimensional network, and the lithium salt is present in a ratio of the polymer to Li + of about 5:1 to 30:1 based on moles of polymer monomer units and of Li + .

2 . The electrolyte of claim 1 , wherein the c-LLZO is selected from the group consisting of an Al-doped cubic phase Li 7 La 3 Zr 2 O 12 , undoped cubic phase Li 7 La 3 Zr 2 O 12 , Ti-doped Li 7 La 3 Zr 2 O 12 , and Ga-doped Li 7 La 3 Zr 2 O 12 .

3 . The electrolyte of claim 1 , wherein the lithium electrolyte salt is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imidate (LiTFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium trifluoromethanesulfonate (LiTf), lithium perchlorate (LiClO 4 ), lithium bis(oxalato)borate (LiB(C 2 O 4 ) 2 or “LiBOB”), lithium difluoro(oxalato)borate (LiF 2 BC 2 O 4 or “LiDFOB”), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium thiocyanate (LiSCN), lithium bis(fluorosulfonyl)imidate (LiFSI), lithium bis(pentafluoroethylsulfonyl)imidate (LiBETI), lithium tetracyanoborate (LiB(CN) 4 ), lithium nitrate, and a combination of two or more thereof.

4 . The electrolyte of claim 1 , wherein the polymer is selected from the group consisting of polyethylene oxide (PEO), polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyacrylonitrile (PAN), and carboxymethylcellulose (CMC).

5 . The electrolyte of claim 1 , further comprising a first interfacial polymer layer on one surface thereof and a second interfacial polymer layer on a second surface thereof.

6 . The electrolyte of claim 5 , wherein the first interfacial polymer layer comprises PEO and the second interfacial polymer layer comprises PAN.

7 . The electrolyte of claim 1 , wherein the nanofibers of the c-LLZO are covalently bonded to the polymer.

8 . The electrolyte of claim 1 , wherein the polymer is formed in situ by polymerization of one or more monomers in the presence of the nanofibers of the c-LLZO.

9 . The electrolyte of claim 1 , wherein the polymer is cross-linked in situ by adding a cross-linking agent to the polymer in the presence of the nanofibers of the c-LLZO.

10 . The electrolyte of claim 1 , wherein the nanofibers of the c-LLZO have a fiber diameter in the range of about 100 nm to about 10,000 nm.

11 . A multilayer solid-state electrochemical cell comprising a multilayer sheet in the following layer order, in the direction from anode to cathode:
(a) an anode current collector layer; (b) an anode layer comprising an anode active material; (c) a solid-state electrolyte layer comprising a lithium electrolyte salt, at least about 55 wt % nanofibers of a first cubic phase lithium lanthanum zirconium oxide (c-LLZO), and a first polymer interspersed with the nanofibers and electrolyte salt; wherein the nanofibers of the first c-LLZO are interconnected in a three-dimensional network, and the lithium salt is present in a ratio of the polymer to Li + of about 5:1 to 30:1 based on moles of polymer monomer units and of Li + ; (d) a cathode layer comprising a cathode active material dispersed in a second polymer; and (e) a cathode current collector layer; wherein adjacent layers in the sheet contact each other and adhere together to form the solid-state electrochemical cell.

12 . The electrochemical cell of claim 11 , wherein the first c-LLZO is selected from the group consisting of an Al-doped cubic phase Li 7 La 3 Zr 2 O 12 , undoped cubic phase Li 7 La 3 Zr 2 O 12 , Ti-doped Li 7 La 3 Zr 2 O 12 , and Ga-doped Li 7 La 3 Zr 2 O 12 .

13 . The electrochemical cell of claim 11 , wherein the cathode layer further comprises nanofibers of a second c-LLZO dispersed in the second polymer, and at least a portion of the cathode active material is in the form of nanofibers.

14 . The electrochemical cell of claim 13 , wherein at least a portion of the cathode active material is in the form of particles.

15 . The electrochemical cell of claim 13 , wherein the second c-LLZO is selected from the group consisting of an Al-doped cubic phase Li 7 La 3 Zr 2 O 12 , undoped cubic phase Li 7 La 3 Zr 2 O 12 , Ti-doped Li 7 La 3 Zr 2 O 12 , and Ga-doped Li 7 La 3 Zr 2 O 12 .

16 . The electrochemical cell of claim 11 , wherein the lithium electrolyte salt is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imidate (LiTFSI), lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium trifluoromethanesulfonate (LiTf), lithium perchlorate (LiClO 4 ), lithium bis(oxalato)borate (LiB(C 2 O 4 ) 2 or “LiBOB”), lithium difluoro(oxalato)borate (LiF 2 BC 2 O 4 or “LiDFOB”), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium thiocyanate (LiSCN), lithium bis(fluorosulfonyl)imidate (LiFSI), lithium bis(pentafluoroethylsulfonyl)imidate (LiBETI), lithium tetracyanoborate (LiB(CN) 4 ), lithium nitrate, and a combination of two or more thereof.

17 . The electrochemical cell of claim 11 , wherein the first polymer is selected from the group consisting of PEO, PVDF, PMMA, PC, PAN, and CMC; and the second polymer is selected from the group consisting of PAN, PVDF, PMMA, and CMC.

18 . The electrochemical cell of claim 11 , wherein the cathode active material is selected from the group consisting of (a) LiNi x Mn y Co z O 2 (NMC) wherein x+y+z=1, 0<x<1, 0<y<1, and 0<z <1, (b) LiNi 0.5 Mn 1.5 O 4 (LNMO), (c) LiMn 2 O 4 (LMO), (d) LiFePO 4 (LFP), (e) lithium nickel cobalt aluminum oxide (NCA), (f) lithium nickel manganese aluminum oxide, (g) lithium cobalt oxide (LCO), (h) Li 3 V 2 (PO 4 ) 3 , and (i) Li—S.

19 . The electrochemical cell of claim 11 , further comprising a first interfacial polymer layer between the anode layer and the solid-state electrolyte layer; and a second interfacial polymer layer between the solid-state electrolyte layer and the cathode layer.

20 . The electrochemical cell of claim 19 , wherein the first interfacial polymer layer comprises PEO and the second interfacial polymer layer comprises PAN.

21 . The electrochemical cell of claim 11 , wherein the anode current collector layer comprises a copper foil or a carbon material selected from the group consisting of carbon nanofibers, graphite sheets, carbon paper, carbon nanotubes, and graphene; and the cathode current collector layer comprises an aluminum foil or a carbon material selected from the group consisting of carbon nanofibers, graphite sheets, carbon paper, carbon nanotubes, and graphene.

22 . The electrochemical cell of claim 11 , wherein the nanofibers of the first c-LLZO have a fiber diameter in the range of about 100 nm to about 10,000 nm.

23 . The electrochemical cell of claim 11 , wherein the cathode comprises nanofibers of the cathode active material; particles of the cathode active material; nanofibers of a second c-LLZO; and parti

Assignees

• Uchicago Argonne Llc

Inventors

• Zhang Yuepeng
• Tepavcevic Sanja
• Powers Devon J
• Zapol Peter
• Hryn John N
• Krumdick Gregory K
• Kahvecloglu Ozgenur
• Pupek Krzystof Z
• Counihan Michael John

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2300/0091

  in the form of mixtures · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M10/056 Primary

  characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes · CPC title