Composite anode structure for aqueous electrolyte energy storage and device containing same

• US 8,945,756 B2
• Filed: 08/21/2013
• Issued: 02/03/2015
• Est. Priority Date: 12/12/2012
• Status: Expired due to Fees

• Current Assignee: Aquion Energy, Inc. (Juline-Titans Holdings Group Co. LLC)
• Original Assignee: Aquion Energy, Inc. (Juline-Titans Holdings Group Co. LLC)
• Inventors: Whitacre, Jay, Mohamed, Alex, Polonsky, Andrew, Shanbhag, Sneha, Carlisle, Kristen
• Primary Examiner(s): Huff, Mark F
• Assistant Examiner(s): WILLS, MONIQUE M
• Application Number:
  US13/972,409
• Publication Number:
  US 20140159668A1
• Time in Patent Office: 531 Days
• Field of Search: 320/130, 320/128, 252/507, 429/158, 429/188, 429/206, 429/231.5, 429/347
• US Class Current: 429/158
• CPC Class Codes: H01G 11/04 Hybrid capacitors
• CPC Class Codes: H01G 11/06 with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/50 specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
• CPC Class Codes: H01G 11/60 characterised by the solvent
• CPC Class Codes: H01G 11/62 characterised by the solute, e.g. salts, anions or cations therein
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 2300/0002 Aqueous electrolytes
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 50/209 adapted for prismatic or rectangular cells H01M50/216 takes precedence
• CPC Class Codes: H01M 50/244 Secondary casings; Racks; Suspension devices; Carrying devices; Holders characterised by their mounting method
• CPC Class Codes: H01M 50/271 Lids or covers for the racks or secondary casings
• CPC Class Codes: H01M 50/289 characterised by spacing elements or positioning means within frames, racks or packs spacing elements inside cells other than separators, membranes or diaphragms H01M50/471
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

An anode electrode for an energy storage device includes both an ion intercalation material and a pseudocapacitive material. The ion intercalation material may be a NASICON material, such as NaTi₂(PO₄)₃ and the pseudocapacitive material may be an activated carbon material. The energy storage device also includes a cathode, an electrolyte and a separator.

Claims

1. A method of operating the energy storage device comprising a plurality of electrically connected electrochemical energy storage cells, wherein each cell comprises a negative anode electrode comprising both an ion intercalation material and an electrochemical double layer capacitive and/or pseudocapacitive material, a positive cathode electrode, a separator, and an aqueous electrolyte,

the method comprising charging and discharging the plurality of electrochemical energy storage cells, wherein the electrochemical double layer capacitive and/or pseudocapacitive material protects the ion intercalation material from corrosion by gettering hydrogen species that evolve during the charging step.

2. The method of claim 1, wherein:

on charging, water in the aqueous electrolyte electrolyzes to form hydrogen and OH⁻

species at an anode electrode of at least one of the plurality of cells when a charge storage capacity of the anode electrode of the at least one cell is exceeded on charging the at least one cell, the OH⁻

species increase a pH proximal to the anode electrode surface, and the increase in pH lowers a voltage stability window of the electrolyte, thereby reducing or eliminating further hydrogen evolution; and

on discharging, the hydrogen species formed on charging of the at least one cell combines with the OH⁻

species.

3. The method of claim 2, wherein the steps of charging and discharging have a cycle time of greater than 1 hour, and wherein the step of charging comprises charging the storage device at a voltage 1.5 times greater or 0.8 volts higher than a voltage at which electrolysis of the water at the anode electrode is initiated under pH 7 conditions.

4. The method of claim 2, wherein the double layer capacitive and/or pseudocapacitive material comprises an activated carbon, the intercalation material comprises NaTi₂(PO₄)₃, and the activated carbon material protects the NaTi₂(PO₄)₃ material from the corrosion by gettering the hydrogen species that evolve during the charging step.

5. The method of claim 4, wherein during the steps of charging and discharging the NaTi₂(PO₄)₃ material reversibly intercalates and deintercalates alkali metal cations from the electrolyte and the activated carbon material undergoes a partial non-Faradaic charge transfer surface interaction with the alkali metal cations while also having an ability to store hydrogen species upon overcharge without substantial decrease in capacity over at least 100 cycles.

6. The method of claim 1, further comprising maintaining the plurality of electrochemical energy storage cells at temperatures ranging from 30 to 90°

C. during the steps of charging and discharging.

7. The method of claim 1, wherein the electrolyte is saturated with one or more of Na₂SO₄, Li₂SO₄, NaClO₄, LiCO₄, NaNO₃, LiNO₃ and MnClO₄ salts solvated in water such that no manganese ions dissolve into the electrolyte from the cathode during the steps of charging and discharging.

8. The method of claim 1, wherein:

the intercalation material comprises a NASICON material having a formula Na_xLi_(1-x)Ti₂(PO₄)₃, where 0.05≦

x≦

1;

the double layer capacitive and/or pseudocapacitive material comprises an activated carbon having a surface area between 400 and 1500 m²/g; and

during the charging step, the NASICON material intercalates at least one of Li, Na and K alkali cations from the electrolyte regardless of which alkali species is resident in the NASICON material depending on alkali cation availability in the electrolyte and intercalation affinity, such that one or more of Li, Na and K intercalate and reside in the host NASICON material structure to form a fully charged intercalation material that has a formula A₂Li_xNa_(1-x)Ti₂(PO₄)₃, where A is one or more of Li, Na and K.

9. The method of claim 1, wherein the anode electrode comprises a composite of the ion intercalation material and the electrochemical double layer capacitive and/or pseudocapacitive material.

10. The method of claim 9, wherein the composite is formed by blending NaTi₂(PO₄)₃ and activated carbon.

11. The method of claim 10, wherein the blend ranges from 0.5:

9 to 9.5;

0.5 mass ratio of NaTi₂(PO₄)₃;

activated carbon.

12. The method of claim 11, wherein the blend ranges from 1:

9 to 9;

1 mass ratio of NaTi₂(PO₄)₃;

activated carbon.

13. The method of claim 12, wherein the blend ranges from 1:

4 to 4;

1 mass ratio of NaTi₂(PO₄)₃;

activated carbon.

14. The method of claim 13, wherein the blend ranges from 2:

3 to 3;

2 mass ratio of NaTi₂(PO₄)₃;

activated carbon.

15. The method of claim 14, wherein the blend contains an about 1:

1 mass ratio of NaTi₂(PO₄)₃;

activated carbon.

16. The method of claim 1, wherein at least a portion of the plurality of electrochemical storage cells comprise anode limited electrochemical storage cells.

17. The method of claim 1, further comprising overcharging at least one of the plurality of electrochemical storage cells during a charging step.

18. The method of claim 5, wherein the NaTi₂(PO₄)₃ material in the negative anode electrode reversibly intercalates and deintercalates sodium cations from the electrolyte which comprises a Na₂SO₄ aqueous electrolyte.

19. The method of claim 18, wherein the anode electrode comprises a solid free standing anode electrode on a current collector and the anode electrode comprises a porous crystalline structure that is filled with the electrolyte.

20. The method of claim 1, wherein the anode electrode comprises a solid composite of the ion intercalation material and the electrochemical double layer capacitive and/or pseudocapacitive material having a porous crystalline structure that is filled with the electrolyte.