High capacity lithium ion battery formation protocol and corresponding batteries

• US 9,553,301 B2
• Filed: 08/24/2015
• Issued: 01/24/2017
• Est. Priority Date: 08/19/2011
• Status: Active Grant

• Current Assignee: Zenlabs Energy, Inc.
• Original Assignee: Envia Systems, Inc.
• Inventors: Amiruddin, Shabab, Li, Bing
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US14/833,441
• Publication Number:
  US 20150364748A1
• Time in Patent Office: 519 Days
• Field of Search: 429/188, 429/206, 429/220, 429/223, 429/231.5, 320/107, 320/128, 320/130, 320/141, 320/160, 324/426, 324/427, 324/431, 324/433
• US Class Current: 1/1
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/056 characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 4/0447 of complete cells or cells stacks
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/362 Composites
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Battery formation protocols are used to perform initial charging of batteries with lithium rich high capacity positive electrode to result a more stable battery structure. The formation protocol generally comprises three steps, an initial charge step, a rest period under an open circuit and a subsequent charge step to a selected partial activation voltage. The subsequent or second charge voltage is selected to provide for a desired degree of partial activation of the positive electrode active material to achieve a desired specific capacity while providing for excellent stability with cycling. The formation protocol is particularly effective to stabilize cycling for compositions with moderate lithium enrichment.

Claims

1. A method for the formation of a lithium ion secondary battery comprising a lithium rich metal oxide composition, a negative electrode, a separator between the positive electrode and negative electrode, and an electrolyte comprising lithium ions, the method comprising:

performing a first charge of the battery to a voltage from about 2.1 V to about 4.225V;

after completing the first charge, holding the battery at an open circuit for a rest period at a temperature from about 35°

C. to about 75°

C.;

performing a second charge after the completion of the rest period to a voltage from about 4.275V to about 4.39V;

discharging the battery after the second charge to a voltage no more than about 2.75V; and

partially charging the battery for distribution to users.

2. The method of claim 1 wherein the first charge of the battery is to a voltage from about 3.95V to about 4.22V.

3. The method of claim 1 wherein the battery is held at an open circuit rest period from about 8 hours to about 8 days.

4. The method of claim 1 wherein the second charge after the rest period is to a voltage from about 4.28V to about 4.38V.

5. The method of claim 1 wherein the lithium rich metal oxide is approximately represented by Li_1+xM₁₋

yO₂, where M represents one or more non-lithium metals, x is from about 0.01 to about 0.33, and y is from about x−

0.2 to about x+0.2 with the proviso that y≧

0 wherein y is related to x based on the average valence of the metals.

6. The method of claim 1 wherein the lithium rich metal oxide is approximately represented by Li_1+bNi_α

Mn_β

Co_γ

A_δ

O<sub>2−

z</sub>F_z, where b ranges from about 0.01 to about 0.3, a ranges from about 0 to about 0.4, β

range from about 0.2 to about 0.65, γ

ranges from 0 to about 0.46, δ

ranges from 0 to about 0.15 and z ranges from 0 to about 0.2 with the proviso that both α and

γ

are not zero, and where A is a metal different from Mn, Ni, or Co and wherein after charging the battery to 4.35V and storing the battery at an open circuit voltage for one week, the negative electrode of the battery comprises no more than about 125 ppm of the combination of Mn, Co and Ni.

7. The method of claim 1 wherein after cycling for 2500 cycles between 4.24V to 2.73V at a 1 C Charge and 2 C discharge, the battery maintains at least 92% of capacity.

8. The method of claim 1 wherein after performing the formation steps the battery has a calendar life at an 85% state of charge at 30 degrees C. of at least about 2 years based on discharge capacity decay of no more than about 20%.

9. A method for the formation of a lithium ion secondary battery comprising a lithium rich metal oxide composition, a negative electrode, a separator between the positive electrode and negative electrode, and an electrolyte comprising lithium ions, the method comprising:

performing a first charge of the battery to a voltage from about 3.95 V to about 4.225V;

after completing the first charge, holding the battery at an open circuit for a rest period at a temperature from about 35°

C. to about 75°

C.;

performing a second charge after the completion of the rest period to a voltage from about 4.275V to about 4.39V.

10. The method of claim 9 wherein the battery is held at an open circuit rest period from about 8 hours to about 8 days.

11. The method of claim 9 wherein the lithium rich metal oxide is approximately represented by Li_1+xM₁₋

yO₂, where M represents one or more non-lithium metals, x is from about 0.01 to about 0.33, and y is from about x−

0.2 to about x+0.2 with the proviso that y≧

0 wherein y is related to x based on the average valence of the metals.

12. The method of claim 9 wherein the lithium rich metal oxide is approximately represented by Li_1+bNi_α

Mn_β

Co_γ

A_δ

O<sub>2−

z</sub>F_z, where b ranges from about 0.01 to about 0.3, α

ranges from about 0 to about 0.4, β

range from about 0.2 to about 0.65, γ

ranges from 0 to about 0.46, δ

ranges from 0 to about 0.15 and z ranges from 0 to about 0.2 with the proviso that both α and

γ

are not zero, and where A is a metal different from Mn, Ni, or Co and wherein after charging the battery to 4.35V and storing the battery at an open circuit voltage for one week, the negative electrode of the battery comprises no more than about 125 ppm of the combination of Mn, Co and Ni.

13. The method of claim 12 wherein at the 200th cycle, the battery has a specific discharge capacity based on the mass of the positive electrode active composition of at least about 140 mAh/g at a discharge rate of 1 C from 4.35V to 2.0V that is at least about 97% of the 5th cycle specific discharge capacity.

14. A method for the formation of a lithium ion secondary battery comprising a lithium rich metal oxide composition, a negative electrode, a separator between the positive electrode and negative electrode, and an electrolyte comprising lithium ions, the method comprising:

performing a first charge of the battery to a voltage from about 2.1 V to about 4.225V;

after completing the first charge, holding the battery at an open circuit for a rest period at a temperature from about 35°

C. to about 70°

C.; and

performing a second charge after the completion of the rest period to a voltage from about 4.275V to about 4.39V,

wherein the electrolyte comprises LiPF₆ and/or LiBF₄ at a total concentration from about 0.9M to about 2.5M and a solvent comprising ethylene carbonate and an organic solvent comprising dimethyl carbonate, methyl ethyl carbonate, γ

-butyrolactone, γ

-valerolactone or a combination thereof.

15. The method of claim 14 wherein the electrolyte further comprises from about 0.01 weight percent to about 5 weight percent of lithium difluoro oxalato borate or lithium bis(oxalato)borate.

16. The method of claim 14 wherein the battery is held at an open circuit rest period from about 8 hours to about 8 days.

17. The method of claim 14 wherein the lithium rich metal oxide is approximately represented by Li_1+xM₁₋

yO₂, where M represents one or more non-lithium metals, x is from about 0.01 to about 0.33, and y is from about x−

0.2 to about x+0.2 with the proviso that y≧

0 wherein y is related to x based on the average valence of the metals.

18. The method of claim 14 wherein after performing the formation steps the battery has a calendar life at an 85% state of charge at 30 degrees C. of at least about 2 years based on discharge capacity decay of no more than about 20%.

19. A method for the formation of a lithium ion secondary battery comprising a lithium rich metal oxide composition, a negative electrode, a separator between the positive electrode and negative electrode, and an electrolyte comprising lithium ions within a sealed housing wherein the lithium rich metal oxide is approximately represented by Li_1+xM₁₋

yO₂, where M represents one or more non-lithium metals, x is from about 0.01 to about 0.33, and y is from about x−

0.2 to about x+0.2 with the proviso that y≧

0 wherein y is related to x based on the average valence of the metals, the method comprising;

performing a first charge of the battery to a voltage from about 2.1 V to about 4.225V;

after completing the first charge, holding the battery at an open circuit for a rest period of at least about 6 hours; and

performing a second charge after the completion of the rest period to a voltage from about 4.275V to about 4.39V;

venting oxygen from the battery resulting from the formation process.

20. The method of claim 19 wherein the battery is held at an open circuit rest period from about 8 hours to about 8 days.

21. The method of claim 19 wherein the battery is maintained at a temperature from about 35°

C. to about 70°

C. during the rest period.