Cathode slurry for secondary battery

Patent metadata

Field	Value
Publication number	US-11855272-B2
Application number	US-202017617590-A
Country	US
Kind code	B2
Filing date	Apr 8, 2020
Priority date	Jun 13, 2019
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

A cathode slurry comprises a cathode active material, especially a nickel-containing cathode active material, a binder, a solvent and a base having a formula of R 1 R 2 R 3 N, with improved stability in water. Pre-treatment of nickel-containing cathode active materials may improve stability of the cathode by preventing undesirable decomposition of the material. In addition, battery cells comprising the cathode prepared by the cathode slurry exhibit impressive electrochemical performances.

First claim

What is claimed is:

1. A cathode slurry for a secondary battery, comprising a cathode active material, a binder, a solvent and a base having a formula of R 1 R 2 R 3 N, wherein each of R 1 , R 2 and R 3 is independently H, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 heteroalkyl, C 4-6 cycloalkylalkyl, C 2-6 alkoxyalkyl, or C 3-6 alkoxyalkoxyalkyl, where the C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 heteroalkyl, C 4-6 cycloalkylalkyl, C 2-6 alkoxyalkyl, or C 3-6 alkoxyalkoxyalkyl is optionally substituted with one or more substituents, where each of the substituents is independently alkyl or cycloalkyl, wherein the base is selected from the group consisting of ammonia, methylamine, ethylamine, propylamine, isopropylamine, cyclopropylamine, butylamine, N-butylamine, tert-butylamine, isobutylamine, sec-butylamine, cyclobutylamine, dimethylamine, N-ethylmethylamine, diethylamine, N-methylpropylamine, N-methylcyclopropanamine, N-ethyl-N-propylamine, N,2-dimethyl-1-propanamine, N-tert-butylmethylamine, diisopropylamine, N-methyl-tert-butylamine, trimethylamine, N,N-dimethylethylamine, N,N-diethylmethylamine, N,N-dimethylisopropylamine, triethylamine and combinations thereof, and wherein the cathode slurry has a pH of greater than 8 and less than 14.

2. The cathode slurry of claim 1 , wherein each of R 1 , R 2 and R 3 is independently C 1-4 alkyl, C 3-5 cycloalkyl, C 1-4 heteroalkyl, C 2-4 alkoxyalkyl, or C 3-5 alkoxyalkoxyalkyl.

3. The cathode slurry of claim 1 , wherein each of R 1 , R 2 and R 3 is independently H, methyl, ethyl, propyl, isopropyl, cyclopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, cyclobutyl, pentyl, methoxymethyl, ethoxymethyl, or methoxyethoxymethyl.

4. The cathode slurry of claim 1 , wherein the cathode active material is selected from the group consisting of Li 1+x Ni a Mn b Co c Al (1−a−b−c) O 2 , LiNi 0.33 Mn 0.33 Co 0.33 O 2 , LiNi 0.4 Mn 0.4 Co 0.2 O 2 , LiNi 0.5 Mn 0.3 Co 0.2 O 2 , LiNi 0.6 Mn 0.2 Co 0.2 O 2 , LiNi 0.7 Mn 0.15 Co 0.15 O 2 , LiNi 0.8 Mn 0.1 Co 0.1 O 2 , LiNi 0.92 Mn 0.04 Co 0.04 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , and combinations thereof; wherein −0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1.

5. The cathode slurry of claim 1 , wherein the cathode active material comprises or is a core-shell composite having a core and shell structure, wherein the core and the shell each independently comprise a lithium transition metal oxide selected from the group consisting of Li 1+x Ni a Mn b Co c Al (1−a−b−c) O 2 , LiCoO 2 , LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiCrO 2 , Li 4 Ti 5 O 12 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , and combinations thereof; wherein −0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1.

6. The cathode slurry of claim 5 , wherein the shell comprises a lithium transition metal oxide selected from the group consisting of LiNi 0.33 Mn 0.33 Co 0.33 O 2 , LiNi 0.4 Mn 0.4 Co 0.2 O 2 , LiNi 0.5 Mn 0.3 Co 0.2 O 2 , LiNi 0.6 Mn 0.2 Co 0.2 O 2 , LiNi 0.7 Mn 0.15 Co 0.15 O 2 , LiNi 0.8 Mn 0.1 Co 0.1 O 2 , LiNi 0.92 Mn 0.04 Co 0.04 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiNiO 2 , and combinations thereof.

7. The cathode slurry of claim 1 , wherein the solvent is water or a mixture of water and an alcohol.

8. The cathode slurry of claim 7 , wherein the alcohol is selected from the group consisting of ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, and combinations thereof.

9. The cathode slurry of claim 7 , wherein the alcohol comprises from about 1% to about 30% of the total weight of the cathode slurry.

10. The cathode slurry of claim 1 , further comprising a conductive agent that is selected from the group consisting of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanoplatelets, carbon fibers, carbon nano-fibers, graphitized carbon flake, carbon tubes, carbon nanotubes, activated carbon, mesoporous carbon and combinations thereof.

11. The cathode slurry of claim 1 , wherein the base has a boiling point of lower than 100° C. at a pressure of 1 atm.

12. The cathode slurry of claim 1 , wherein the base in the cathode slurry is at a concentration of from about 0.5% to about 3.5% by weight, based on the total weight of the cathode slurry.

13. The cathode slurry of claim 1 , wherein the cathode slurry has a pH of from about 11 to about 13.5.

14. The cathode slurry of claim 1 , wherein the binder material is selected from the group consisting of styrene-butadiene rubber, carboxymethyl cellulose, polyvinylidene fluoride, acrylonitrile copolymer, polyacrylic acid, polyacrylonitrile, poly(vinylidene fluoride)-hexafluoropropene, latex, a salt of alginic acid, and combinations thereof.

15. The cathode slurry of claim 14 , wherein the salt of alginic acid comprises a cation selected from the group consisting of Na, Li, K, Ca, NH 4 , Mg, Al, and combinations thereof.

16. The cathode slurry of claim 1 , wherein lithium loss of the cathode active material is inhibited by a percentage from about 1 percent to about 50 percent.

17. The cathode slurry of claim 1 , wherein lithium loss of the cathode active material is inhibited by a percentage of about 10 percent or above.

18. The cathode slurry of claim 1 , wherein the cathode slurry has a solid content of from about 45% to about 75% by weight, based on the total weight of the cathode slurry.

19. The cathode slurry of claim 1 , wherein the cathode slurry is free of a dispersing agent selected from the group consisting of a cationic surfactant, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and a polymeric acid.

Assignees

• Grst Int Ltd

Inventors

• Ho Kam Piu
• Jiang Yingkai

Classifications

• H01M4/0404 Primary

  by coating on electrode collectors · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/505 Primary

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

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/623

  fluorinated polymers · CPC title