Solvent systems for use in lithium ion battery production
In the process of producing a lithium ion battery, one or more compounds of Formula 1, 2, 3 or 4 (e.g., N,N-dimethylpropionamide), is used as the solvent in the step of forming a slurry from an active material (e.g., lithium cobalt oxide), a conductive agent (e.g., carbon black), and a binder polymer (e.g., polyvinylidene fluoride).
1. A process of making a lithium ion battery cathode or anode, the process comprising the steps of:
forming a slurry consisting of an active material, a conductive agent, a binder polymer that is polyvinylidene fluoride, and a solvent, the solvent consisting of one or more of a first compound of Formula 1
in which R 1 and R 2 are hydrogen or a C1-4 straight or branched chain alkyl or alkoxy, and R 3 is a C1-10 straight or branched chain alkyl or alkoxy, with the proviso that R 1 and R 2 are not both hydrogen; or
one or more of a second compound of Formula 2
in which R 2 ′ is 2-9 ring carbon atoms each of which can have a C1-2 alkyl or alkoxy branch, and R 1 ′ is a C2-8 straight or branched chain alkyl or alkoxy; or
one or more of a third compound of Formula 3
in which R 1 ″ and R 2 ″ are hydrogen or a C1-2 alkyl or alkoxy; R 3 ″ is 2-4 ring carbons each of which can have a C1-2 alkyl or alkoxy branch; and R 4 ″ is hydrogen or a C1-3 straight or branched chain alkyl or alkoxy, or
one or more of a fourth compound of Formula 4
in which R 1 ″ is 5-9 ring carbons each of which can have a C1-2 alkyl or alkoxy branch; and R 2 ′″ is hydrogen or a C1-3 straight or branched chain alkyl or alkoxy; and applying the slurry to a foil.
2. The process of claim 1 in which the solvent consists of a compound of Formula 1.
3. The process of claim 2 in which the solvent is N,N-dimethylpropionamide.
4. The process of claim 1 in which the solvent consists of a compound of Formula 2.
5. The process of claim 4 in which the solvent is N,N-diethyl acetamide.
6. The process of claim 1 in which the solvent consists of a compound of Formula 3.
7. The process of claim 6 in which the solvent is 3-methoxy-N,N-dimethyl propionamide.
8. The process of claim 1 in which the solvent consists of a compound of Formula 4.
9. The process of claim 8 in which the solvent is N,N-dimethylbutyramide.
10. A cathode or anode comprising the foil made by the process of claim 1 .
11. A lithium ion battery comprising the cathode or anode of claim 10 .
12. The process of claim 1 wherein the solvent is selected from the group consisting of N,N-diethyl acetamide, 3-methoxy-N,N-dimethyl propionamide, and N, N-dimethylpropionamide.
13. A process of making a lithium ion battery cathode or anode, the process comprising:
forming a slurry consisting of (i) an active material, (ii) a conductive agent, (iii) a binder polymer selected from the group consisting of polyvinylidene fluoride, cellulose, and styrene butadiene rubber, and (iv) a solvent, the solvent selected from the group consisting of
N,N-dimethylpropionamide (DMPA), N,N-diethylpropionamide, N,N-dipropylpropionamide, N,N-dibutylpropionamide, N,N-dimethylethylpropionamide, 3-butoxy-N-methyl propionamide,
N,N-diethyl acetamide (DEAC), N-ethyl-ε-caprolactam,
3-methoxy-N,N-dimethyl propionamide (M3DMPA), N-acetyl morpholine,
N,N-dimethylbutyramide (DMAA), N-propionyl-ε-caprolactam, and combinations thereof; and applying the slurry to a foil.
14. The process of claim 13 wherein the binder polymer is polyvinylidene fluoride.
15. The process of claim 14 wherein the solvent is selected from the group consisting of N,N-diethyl acetamide, 3-methoxy-N,N-dimethyl propionamide (M3DMPA), N,N-dimethylpropionamide (DMPA), and combinations thereof.
16. The process of claim 15 wherein the solvent is N,N-diethyl acetamide.
17. The process of claim 15 wherein the solvent is 3-methoxy-N,N-dimethyl propionamide.
18. The process of claim 15 wherein the solvent is N, N-dimethylpropionamide.