Composite electrolytes with binders
Functionalized polymeric binders for electrolyte and electrode compositions include a polymer having a polymer backbone and functional groups. In some embodiments, a polymer includes a non-polar polymer backbone and a functional group that is 0.1 to 5 wt % of the polymer. In some embodiments, a polymer includes a polar backbone and a functional group that is 0.1 to 50% weight percent of the polymer. Also described are composites for electrolyte separators and electrodes that include argyrodite ion conductors and polar polymers.
1. A composite comprising:
inorganic ionically conductive particles; and
an organic phase comprising a polymer binder having a molecular weight of at least 30 kg/mol, wherein the polymer binder comprises a backbone modified with functional groups, the functional groups being in side chains off the backbone and the functional groups being between 0.1 and 5 wt. % of the polymer binder, wherein the polymer binder comprises styrene-ethylene-butylene-styrene (SEBS) modified with furfurylamine (SEBS-gFA).
2. The composite of claim 1 , wherein the organic phase comprises a mixture of unmodified SEBS and SEB-gFA.
3. The composite of claim 1 , wherein the inorganic ionically conductive particles are argyrodites.
4. The composite of claim 1 , wherein the inorganic ionically conductive particles are sulfide glass particles.
5. The composite of claim 1 , wherein the composite has an elongation at break of at least 10%.
6. A slurry comprising:
a solvent;
a polymer binder having a molecular weight of at least 30 kg/mol dissolved in the solvent,
the polymer binder comprises a backbone modified with functional groups in side chains off the backbone and the functional groups being between 0.1 and 5 wt. % of the polymer binder; and
ionically conductive sulfidic particles suspended in the solvent,
wherein the polymer binder comprises styrene-ethylene-butylene-styrene (SEBS) modified with furfurylamine (SEBS-gFA).
7. The slurry of claim 6 , wherein the slurry comprises a mixture of unmodified SEBS and SEBS-gFA.
8. The slurry of claim 6 , wherein the solvent is at least 50% wt of the slurry.
9. The composite of claim 3 , wherein the argyrodites comprise argyrodites with the formula: Li 7−x PS 6−x X x (X═Cl, Br, I, and 0<x<2).
10. The composite of claim 3 , wherein the argyrodites comprise argyrodites doped with a thiophilic metal selected from manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and mercury (Hg).
11. The composite of claim 3 , wherein the argyrodites comprises argyrodites of the formula: A 7−x−(z*m) M z m PS 6−x Hal x wherein A is an alkali metal; M is a metal selected from manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and mercury (Hg); Hal is selected from chlorine (Cl), bromine (Br), and iodine (I); z is the oxidation state of the metal; 0≤x≤2; and 0≤m<(7−x)/z.
12. The composite of claim 1 , wherein the composite is an electrolyte separator in a battery.
13. The composite of claim 1 , wherein the composite further comprises an electrode active material.
14. The composite of claim 1 , wherein the composite further comprises a silicon-containing material.
15. The composite of claim 14 , wherein the silicon-containing material is elemental silicon (Si) or a silicon-carbon composite material.
16. The composite of claim 14 , wherein the silicon-containing material is a silicon alloy.
17. The composite of claim 14 , wherein the composite is an electrode layer in a battery.
18. The composite of claim 1 , wherein the composite has an ionic conductivity of at least 0.6 mS·cm −1 at 25° C.
19. The composite of claim 1 , wherein the composite has an elongation at break of at least 5%.
20. The composite of claim 1 , wherein the composite has an ionic conductivity of at least 0.2 mS·cm −1 at 25° C.
21. The composite of claim 19 , wherein the composition has an elongation at break of at least 15%.
22. The composite of claim 1 , wherein the composition has an elongation at break of at least 20%.
23. The composite of claim 1 , wherein the weight percentage of the inorganic ionically conductive particles in the composite is no more than 90%.
24. The composite of claim 1 , wherein the organic phase comprises a mixture of unmodified SEBS and SEB-gFA.
25. The slurry of claim 6 , wherein the solvent has a polarity index of less than 3.5.
26. The slurry of claim 6 , wherein the solvent is halogenated and has a polarity index of higher than 3.5.