Block copolymer electrolytes containing polymeric additives
Polymer electrolytes incorporating PS-PEO block copolymers, PXE additives, and lithium salts provide improved physical properties relative to PS-PEO block copolymers and lithium salt alone, and thus provide improved battery performance.
1. An electrolyte material comprising:
a first phase comprising a plurality of first polymers and a salt, the first phase forming an ionically-conductive domain; and
a second phase comprising a plurality of second polymers and third polymers, the second phase forming a structural domain adjacent to the ionically-conductive domain;
wherein at least some of the first polymers are covalently bonded to at least some of the second polymers to form first block copolymers.
2. The electrolyte material of claim 1 wherein at least some of the first polymers are covalently bonded to at least some of the third polymers to form second block copolymers.
3. The electrolyte material of claim 1 wherein the first polymer is selected from the group consisting of polyethers, polyamines, polyimides, polyamides, poly(alkyl carbonates), polynitriles, polysiloxanes, polyphosphazenes, polyolefins, polydienes, and combinations thereof.
4. The electrolyte material of claim 1 wherein the first polymer comprises an ionically-conductive comb polymer, the comb polymer comprising a backbone and pendant groups.
5. The electrolyte material of claim 4 wherein the backbone comprises one or more selected from the group consisting of polysiloxanes, polyphosphazenes, polyethers, polydienes, polyolefins, polyacrylates, polymethacrylates, and combinations thereof.
6. The electrolyte material of claim 4 wherein the pendants comprise one or more selected from the group consisting of oligoethers, substituted oligoethers, nitrile groups, sulfones, thiols, polyethers, polyamines, polyimides, polyamides, poly(alkyl carbonates), polynitriles, other polar groups, and combinations thereof.
7. The electrolyte material of claim 1 wherein the second polymer and the third polymer are each selected independently from the group consisting of polystyrene, hydrogenated polystyrene, polymethacrylate, poly(methyl methacrylate), polyvinylpyridine, polyvinylcyclohexane, polyimide, polyamide, polypropylene, poly(2,6-dimethyl-1,4-phenylene oxide) (PXE), polyolefins, poly(t-butyl vinyl ether), poly(cyclohexyl methacrylate), poly(cyclohexyl vinyl ether), poly(t-butyl vinyl ether), polyethylene, polyfluorocarbons such as polyvinylidene fluoride, or copolymers that contain styrene, methacrylates, and/or vinylpyridine.
8. The electrolyte material of claim 1 wherein the ionically-conductive domain and the structural domain are arranged as alternating lamellar domains.
9. The electrolyte material of claim 8 wherein the ionically-conductive domain and the structural domain each has a width between 5 and 500 nm.
10. The electrolyte material of claim 1 further comprising fourth polymers in the first phase wherein at least some of the fourth polymers are covalently bonded to at least some of the third polymers to form third block copolymers.
11. The electrolyte material of claim 10 wherein the fourth polymers are selected from the group consisting of polyethers, polyamines, polyimides, polyamides, poly(alkyl carbonates), polynitriles, polysiloxanes, polyphosphazenes, polyolefins, polydienes, and combinations thereof.
12. The electrolyte material of claim 1 wherein the salt is a lithium salt.
13. The electrolyte material of claim 1 wherein the electrolyte material is a solid at temperatures between 20° C. and 100° C.
14. The electrolyte material of claim 1 further comprising a liquid electrolyte, wherein the electrolyte material is a gel.
15. The electrolyte material of claim 1 further comprising lithium-ion conducting inorganic ceramics particles in the first phase.
16. The electrolyte material of claim 1 wherein the second phase is cross-linked.
17. A electrolyte material comprising:
an ionically-conductive phase comprising a plurality of PEO polymers and a salt, the ionically-conductive phase forming a first domain; and
a structural phase comprising a plurality of PS polymers and PXE polymers, the structural phase forming a second domain adjacent to the first domain;
wherein at least a portion of the PEO polymers and at least a portion of the PS polymers are covalently bonded together to form first block copolymers.
18. The electrolyte material of claim 17 wherein the first block copolymers are linear block copolymers.
19. The electrolyte material of claim 17 wherein at least a portion of the PEO polymers and a portion of the PXE polymers are covalently bonded together to form second block copolymers.
20. The electrolyte material of claim 19 wherein the second block copolymers are linear block copolymers.
21. A battery electrode, comprising:
electrode active material particles;
an electrolyte material according to claim 1 ; and
optional electronically-conductive particles;
wherein the electrode active material particles and the optional electronically-conductive particles are distributed randomly throughout the electrolyte material.
22. The electrode of claim 21 wherein the electrode is a cathode, and the electrode active material particles comprise a material selected from the group consisting of lithium iron phosphate (LFP), LiCoO 2 , LiMn 2 O 4 , lithium nickel cobalt aluminum oxide (NCA), and lithium nickel cobalt manganese oxide (NCM).
23. The electrode of claim 21 wherein the electrode is an anode, and the electrode active material is selected from the group consisting of graphite, lithium metal, Li—Al, Li—Si, Li—Sn, Li—Mg, Si, Si—Sn, Si—Ni, Si—Cu, Si—Fe, Si—Co, Si—Mn, Si—Zn, Si—In, Si—Ag, Si—Ti, Si—Ge, Si—Bi, Si—Sb, Si—Cr, metal oxides, silicon carbides, and mixtures thereof.