Electrolyte additives
Described herein are additives for use in electrolytes that provide a number of desirable characteristics when implemented within batteries, such as high capacity retention during battery cycling at high temperatures. In some embodiments, a high temperature electrolyte includes a base electrolyte and one or more polymer additives, which impart these desirable performance characteristics.
1. A liquid electrolyte formulation, comprising:
a lithium salt comprising lithium hexafluorophosphate (LiPF 6 ),
a non-aqueous solvent, and
a polymer additive represented by Formula (c):
where n is an integer greater than 1.
2. The liquid electrolyte formulation of claim 1 , wherein a weight average molecular weight of the polymer additive is less than or equal to 12,000 g/mol.
3. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is present at a concentration of at least 0.1 weight percent of the total weight of the liquid electrolyte formulation.
4. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is present at a concentration of at least 0.5 weight percent of the total weight of the liquid electrolyte formulation.
5. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is a homopolymer.
6. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is present at a concentration no greater than 10 weight percent of the total weight of the liquid electrolyte formulation.
7. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is present at a concentration no greater than 3 weight percent of the total weight of the liquid electrolyte formulation.
8. The liquid electrolyte formulation of claim 1 , wherein the polymer additive is present at a concentration within a range of at least 0.5 weight percent and no greater than 2 weight percent of the total weight of the liquid electrolyte formulation.
9. The liquid electrolyte formulation of claim 1 , wherein the non-aqueous solvent comprises one or more carbonates.
10. The liquid electrolyte formulation of claim 1 , wherein the non-aqueous solvent comprises a mixture of ethylene carbonate and ethyl methyl carbonate.
11. The liquid electrolyte formulation of claim 10 , wherein a ratio of the ethylene carbonate to the ethyl methyl carbonate in the liquid electrolyte formulation is 1:2 by volume.
12. The liquid electrolyte formulation of claim 1 , wherein the LiPF 6 is present at a concentration of 1 mol/L (M) in the non-aqueous solvent.
13. A battery comprising:
an anode;
a cathode; and
a liquid electrolyte formulation comprising a lithium salt, a non-aqueous solvent, and a polymer additive, wherein the lithium salt comprises lithium hexafluorophosphate (LiPF 6 ) and the polymer additive is represented by Formula (c):
where n is an integer greater than 1.
14. The battery of claim 13 , wherein the non-aqueous solvent comprises one or more carbonates.
15. The battery of claim 13 , wherein the non-aqueous solvent comprises a mixture of ethylene carbonate and ethyl methyl carbonate.
16. The battery of claim 15 , wherein a ratio of the ethylene carbonate to the ethyl methyl carbonate in the liquid electrolyte formulation is 1:2 by volume.
17. The battery of claim 13 , wherein the LiPF 6 is present at a concentration of 1 mol/L (M) in the non-aqueous solvent.
18. The battery of claim 13 , wherein the anode comprises a graphite composite material.
19. The battery of claim 13 , wherein the cathode comprises a material that includes lithium, nickel, manganese, cobalt, and oxygen.
20. The battery of claim 13 , wherein the polymer additive is present at a concentration within a range of at least 0.5 weight percent and no greater than 2 weight percent of the total weight of the liquid electrolyte formulation.