Sodium conducting energy storage devices comprising compliant polymer seals and methods for making and sealing same

Patent metadata

Field	Value
Publication number	US-2016365548-A1
Application number	US-201615226570-A
Country	US
Kind code	A1
Filing date	Aug 2, 2016
Priority date	Aug 20, 2014
Publication date	Dec 15, 2016
Grant date	—

Abstract

New compliant polymer seals and methods for making and sealing energy storage devices are disclosed. Compliant polymer seals become viscous at the operation temperature which seals cathode and anode chambers following assembly.

First claim

What is claimed is:

1 . An energy-storage device, comprising:
a first polymer seal disposed in at least one junction of a cathode chamber in contact with a primary solid state electrolyte that is inert to a secondary electrolyte therein comprising an alkali-metal aluminum halide; and a second polymer seal disposed in at least one junction of an anode chamber in contact with the primary electrolyte that is inert to sodium metal therein; whereby the seals include a viscosity that seal the respective cathode and anode chambers at operation temperatures from about 100° C. to about 300° C.

2 . The energy-storage device of claim 1 , wherein the first polymer seal comprises a polymer different from the polymer in the second polymer seal.

3 . The energy-storage device of claim 1 , wherein the first polymer seal or the second polymer seal is comprised of ultra-high molecular weight polyethylene.

4 . The energy-storage device of claim 1 , wherein the first polymer seal comprises a polymer selected from: polytetrafluoroethylene (PTFE); fluorinated ethylene propylene (FEP); perfluoroalkoxy alkanes (PFA); or polyethylene (PE).

5 . The energy-storage device of claim 1 , wherein the second polymer seal comprises a polymer selected from polyvinylidene fluoride (PVDF), or polyethylene (PE).

6 . The energy-storage device of claim 1 , wherein the first and second polymer seals are composite seals comprising a viscosity modifier of up to about 50% by weight therein.

7 . The energy-storage device of claim 1 , wherein the first and second polymer seals are composite seals comprising a viscosity modifier that is encapsulated by the first or second polymer therein.

8 . The energy-storage device of claim 1 , wherein the first polymer seal comprises a polymer selected from: polytetrafluoroethylene (PTFE); fluorinated ethylene propylene (FEP); perfluoroalkoxy alkanes (PFA); or polyethylene (PE); and the second polymer seal comprises polyvinylidene fluoride (PVDF).

9 . The energy-storage device of claim 1 , wherein the first polymer seal comprises polytetrafluoroethylene (PTFE) and the second polymer seal comprises polyvinylidene fluoride (PVDF).

10 . The energy-storage device of claim 1 , wherein the first polymer seal comprises polytetrafluoroethylene (PTFE) and the second polymer seal comprises polyethylene (PE).

11 . The energy-storage device of claim 1 , wherein the first polymer seal comprises fluorinated ethylene propylene (FEP) and the second polymer seal comprises polyvinylidene fluoride (PVDF).

12 . The energy-storage device of claim 1 , wherein the first polymer seal comprises fluorinated ethylene propylene (FEP) and the second polymer seal comprises polyethylene (PE).

13 . The energy-storage device of claim 1 , wherein the first polymer seal comprises perfluoroalkoxy alkane (PFA) and the second polymer seal comprises polyvinylidene fluoride (PVDF).

14 . The energy-storage device of claim 1 , wherein the first polymer seal comprises perfluoroalkoxy alkane (PFA) and the second polymer seal comprises polyethylene (PE).

15 . The energy-storage device of claim 1 , further including a metal mesh disposed in the anode chamber in contact with the solid electrolyte therein.

16 . The energy-storage device of claim 1 , further including an anode shim disposed in the anode chamber adjacent the solid electrolyte therein.

17 . A sodium-conducting energy-storage device, comprising:
a sodium ion-conducting solid state electrolyte as a primary electrolyte; a first polymer seal comprising a first polymer selected from polytetrafluoroethylene (PTFE); fluorinated ethylene propylene (FEP); perfluoroalkoxy alkanes (PFA); or polyethylene (PE) disposed in at least one junction of a cathode chamber in contact with the primary electrolyte on the cathode side of the storage device that is inert to a secondary electrolyte comprising a sodium-metal or potassium metal aluminum halide therein; and a metal mesh disposed in the anode chamber in contact with the solid electrolyte configured to maintain contact between sodium metal and the solid electrolyte therein; and a second polymer seal comprising a polymer selected from polyvinylidene fluoride (PVDF); or polyethylene (PE) disposed in at least one junction of an anode chamber in contact with the primary electrolyte on the anode side of the storage device that is inert to sodium metal formed therein; whereby the first and second seals have a selected viscosity that seal the respective cathode and anode chambers and prevent influx of external oxidizing gases therein at operation temperatures above about 100° C. to below about 300° C.

18 . A method for sealing a sodium-conducting energy storage device, comprising the steps of:
introducing a first compliant seal comprising a first polymer selected from polytetrafluoroethylene (PTFE); fluorinated ethylene propylene (FEP); a perfluoroalkoxy alkane (PFA); or polyethylene (PE) disposed in at least one junction of a cathode chamber in contact with a primary electrolyte on the cathode side of the storage device that seals the cathode chamber and is inert to a secondary electrolyte comprising an alkali-metal aluminum halide introduced therein; introducing a second compliant seal comprising a second polymer different from the first polymer selected from polyvinylidene fluoride (PVDF); or polyethylene (PE) disposed in at least one junction of an anode chamber in contact with the primary electrolyte on the anode side of the storage device that seals the anode chamber and components therein preventing influx of the external oxidizing gas therein and is inert to sodium metal formed therein; whereby the first and second seals include a viscosity that seal the respective cathode and anode chambers at a selected operation temperature.

19 . The method of claim 18 , wherein the operation temperature is selected from about 100° C. to about 300° C.

20 . The method of claim 18 , wherein the seals in operation provide a performance degradation in the energy storage device of less than about 5% over at least 200 charge-discharge cycles at a discharge current of 10 mA/cm 2 .

Assignees

• Battelle Memorial Institute

Inventors

• Li Guosheng
• Chang Hee-Jung
• Sprenkle Vincent L

Classifications

• H01M10/39 Primary

  working at high temperature · CPC title

• H01M50/186

  characterised by the disposition of the sealing members · CPC title

• H01M50/193

  Organic material · CPC title

• H01M2/08 Primary

  Electricity · mapped topic

• H01M10/054

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