Method of producing shape-conformable alkali metal-sulfur battery
Provided is method of preparing an alkali metal-sulfur cell, comprising: (a) combining a quantity of a cathode active material (selected from sulfur, a metal-sulfur compound, a sulfur-carbon composite, a sulfur-graphene composite, a sulfur-graphite composite, an organic sulfur compound, a sulfur-polymer composite or a combination thereof), a quantity of an electrolyte, and a conductive additive to form a deformable cathode material, wherein the conductive additive, containing conductive filaments, forms a 3D network of electron-conducting pathways and the electrolyte contains an alkali salt and an ion-conducting polymer dissolved or dispersed in a solvent; (b) forming the cathode material into a quasi-solid cathode, wherein the forming includes deforming the cathode material into an electrode shape without interrupting the 3D network of electron-conducting pathways such that the cathode maintains an electrical conductivity no less than 10 −6 S/cm; (c) forming an anode; and (d) forming a cell by combining the cathode and the anode.
1. A method of preparing an alkali metal-sulfur cell having a quasi-solid electrode, the method comprising:
(a) combining a quantity of a cathode active material, a quantity of a deformable quasi-solid electrolyte, and a conductive additive to form a deformable and electrically conductive cathode material, wherein said deformable quasi-solid electrolyte is not a liquid electrolyte and not a solid electrolyte, wherein said cathode active material contains a sulfur-containing material selected from sulfur, a metal-sulfur compound, a sulfur-carbon composite, a sulfur-graphene composite, a sulfur-graphite composite, an organic sulfur compound, a sulfur-polymer composite, or a combination thereof, and wherein said conductive additive, containing conductive filaments, forms a 3D network of electron-conducting pathways and said deformable quasi-solid electrolyte contains an alkali salt and an ion-conducting polymer selected from the group consisting of poly(perfluoro sulfonic acid), sulfonated polytetrafluoroethylene, sulfonated perfluoroalkoxy derivatives of polytetrafluoroethylene, sulfonated polysulfone, sulfonated poly(ether ketone), sulfonated poly (ether ether ketone), sulfonated polystyrene, sulfonated polyimide, sulfonated styrene-butadiene copolymers, sulfonated poly chloro-trifluoroethylene (PCTFE), sulfonated perfluoroethylene-propylene copolymer (FEP), sulfonated ethylene-chlorotrifluoroethylene copolymer (ECTFE), sulfonated polyvinylidenefluoride (PVDF), sulfonated copolymers of polyvinylidenefluoride with hexafluoropropene and tetrafluoroethylene, sulfonated copolymers of ethylene and tetrafluoroethylene (ETFE), sulfonated polybenzimidazole (PBI), their chemical derivatives, copolymers, blends and combinations thereof and dissolved or dispersed in a solvent with a combined alkali salt/polymer concentration sufficiently high so that said electrolyte exhibits a vapor pressure less than 0.01 kPa or less than 0.6 of a vapor pressure of said solvent alone when measured at 20° C., a flash point at least 20 degrees Celsius higher than a flash point of said solvent alone, a flash point higher than 150° C., or no detectable flash point at all, wherein said step of combining includes dispersing said conductive filaments into said solvent to form a suspension prior to adding said cathode active material in said suspension and prior to dissolving said alkali metal salt and said ion-conducting polymer in said solvent of said suspension, wherein said quasi-solid electrolyte is a supersaturated solution with a concentration greater than 2.5 M;
(b) forming the cathode material into a quasi-solid cathode, wherein said forming includes deforming the cathode material into an electrode shape without interrupting said 3D network of electron-conducting pathways such that the cathode maintains an electrical conductivity no less than 10 −6 S/cm, wherein there are no dry pockets in said quasi-solid cathode;
(c) forming an anode
(d) forming an alkali metal-sulfur cell by combining the quasi-solid cathode and the anode, and
(e) wherein said alkali metal-sulfur cell is a sodium-ion sulfur cell, and said anode contains an anode active material containing an alkali intercalation compound selected from carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, templated carbon, hollow carbon nanowires, hollow carbon sphere, titanates, NaTi 2 (PO 4 ) 3 , Na 2 Ti 3 O 7 , Na 2 C 8 H 4 O 4 , Na 2 TP, Na x TiO 2 l (x= 0.2 to 1.0), carboxylate based materials, C 8 H 6 O 4 , C 8 H 5 NaO 4 , C 8 Na 2 F 4 O 4 , C 10 H 2 Na 4 O 8 , C 14 H 4 O 6 , C 14 H 4 Na 4 O 8 , or a combination thereof.
2. The method of claim 1 , wherein said quasi-solid cathode contains from 30% to 95% by volume of said cathode active material, 5% to 40% by volume of said electrolyte, and 0.01% to 30% by volume of said conductive additive.
3. The method of claim 1 , wherein said conductive filaments are selected from carbon fibers, graphite fibers, carbon nanofibers, graphite nanofibers, carbon nanotubes, needle coke, carbon whiskers, conductive polymer fibers, conductive material-coated fibers, metal nanowires, metal fibers, metal wires, graphene sheets, expanded graphite platelets, a combination thereof, or a combination thereof with non-filamentary conductive particles.
4. The method of claim 1 , wherein said ion-conducting polymer does not form a matrix in said quasi-solid cathode.
5. The method of claim 1 , wherein said quasi-slid cathode maintains an electrical conductivity from 10 −3 S/cm to 10 S/cm.
6. The method of claim 1 , wherein said quasi-solid cathode contains from 0.1% to 20% by volume of the conductive additive.
7. The method of claim 1 , wherein said quasi-solid cathode contains from 1% to 10% by volume of the conductive additive.
8. The method of claim 1 , wherein the quantity of the cathode active material is from 40% to 90% by volume of the cathode material.
9. The method of claim 1 , wherein the quantity of the active material is about 50% to about 85% by volume of the cathode material.
10. The method of claim 1 , wherein said step of forming the anode includes (A) combining a quantity of an anode active material, a quantity of an electrolyte, and a conductive additive to form a deformable and electrically conductive anode material, wherein said conductive additive, containing conductive filaments, forms a 3D network of electron-conducting pathways and said electrolyte contains an alkali salt and an ion-conducting polymer dissolved or dispersed in a solvent; and (B) forming the deformable and conductive anode material into a quasi-solid anode, wherein said forming includes deforming the deformable and conductive anode material into an electrode shape without interrupting said 3D network of electron-conducting pathways such that the anode maintains an electrical conductivity no less than 10 −6 S/cm.
11. The method of claim 1 , wherein said solvent is selected from water, an organic solvent, an ionic liquid, or a mixture of an organic solvent and an ionic liquid.
12. The method of claim 1 , wherein said cathode active material constitutes an electrode active material mass loading greater than 15 mg/cm 2 .
13. The method of claim 1 , wherein said cathode active material constitutes an electrode active material mass loading greater than 25 mg/cm 2 .
14. The method of claim 1 , wherein said cathode active material constitutes an electrode active material mass loading greater than 45 mg/cm 2 .
15. A method of preparing an alkali metal-sulfur cell having a quasi-solid electrode, the method comprising:
(a) combining a quantity of a cathode active material, a quantity of a deformable quasi-solid electrolyte, and a conductive additive to form a deformable and electrically conductive cathode material, wherein said deformable quasi-solid electrolyte is not a liquid electrolyte and not a solid electrolyte, wherein said cathode active material contains a sulfur-containing material selected from sulfur, a metal-sulfur compound, a sulfur-carbon composite, a sulfur-graphene composite, a sulfur-graphite composite, an organic sulfur compound, a sulfur-polymer composite, or a combination thereof, and wherein said conductive additive, containing conductive filaments, forms a 3D network of electron-conducting pathways and said deformable quasi-solid electrolyte contains an alkali salt and an ion-conducting polymer selected from the group consisting of poly(perfluoro sulfonic acid), sulfonated polytetrafluoroethylene, sulfonated perfluoroalkoxy derivatives of polytetrafluoroethylene, sulfonated polysulfone, sulfonated poly(ether ketone), sulfonated poly (ether ether ketone), sulfonated polystyrene, sulfonated polyimide, sulfonated styrene-butadiene copolymers, sulfonated poly chloro-trifluoroethylene (PCTFE), sulfonated perfluoroethylene-propylene copolymer (FEP), sulfonated ethylene-chlorotrifluoroethylene copolymer (ECTFE), sulfonated polyvinylidenefluoride (PVDF), sulfonated copolymers of polyvinylidenefluoride with hexafluoropropene and tetrafluoroethylene, sulfonated copolymers of ethylene and tetrafluoroethylene (ETFE), sulfonated polybenzimidazole (PBI), their chemical derivatives, copolymers, blends and combinations thereof and dissolved or dispersed in a solvent with a combined alkali salt/polymer concentration sufficiently high so that said electrolyte exhibits a vapor pressure less than 0.01 kPa or less than 0.6 of a vapor pressure of said solvent alone when measured at 20° C., a flash point at least 20 degrees Celsius higher than a flash point of said solvent alone, a flash point higher than 150° C., or no detectable flash point at all;
(b) forming the cathode material into a quasi-solid cathode, wherein said forming includes deforming the cathode material into an electrode shape without interrupting said 3D network of electron-conducting pathways such that the cathode maintains an electrical conductivity no less than 10 −6 S/cm;
(c) forming an anode
(d) forming an alkali metal-sulfur cell by combining the quasi-solid cathode and the anode, and
(e) wherein said alkali metal-sulfur cell is a sodium-ion sulfur cell, and said anode contains an anode active material containing an alkali intercalation compound selected from carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, templated carbon, hollow carbon nanowires, hollow carbon sphere, titanates, NaTi 2 (PO 4 ) 3 , Na 2 Ti 3 O 7 , Na 2 C 8 H 4 O 4 , Na 2 TP, Na x TiO 2 (x=0.2 to 1.0), carboxylate based materials, C 8 H 6 O 4 , C 8 H 5 NaO 4 , C 8 Na 2 F 4 O 4 , C 10 H 2 Na 4 O 8 , C 14 H 4 O 6 , C 14 H 4 Na 4 O 8 , or a combination thereof.
16. A method of preparing an alkali metal-sulfur cell having a quasi-solid electrode, the method comprising:
(a) combining a quantity of a cathode active material, a quantity of a deformable quasi-solid electrolyte, and a conductive additive to form a deformable and electrically conductive cathode material, wherein said deformable quasi-solid electrolyte is not a liquid electrolyte and not a solid electrolyte, wherein said cathode active material contains a sulfur-containing material selected from sulfur, a metal-sulfur compound, a sulfur-carbon composite, a sulfur-graphene composite, a sulfur-graphite composite, an organic sulfur compound, a sulfur-polymer composite, or a combination thereof, and wherein said conductive additive, containing conductive filaments, forms a 3D network of electron-conducting pathways and said deformable quasi-solid electrolyte contains an alkali salt and an ion-conducting polymer dissolved or dispersed in a solvent with a combined alkali salt/polymer concentration sufficiently high so that said electrolyte exhibits a vapor pressure less than 0.01 kPa or less than 0.6 of a vapor pressure of said solvent alone when measured at 20° C., a flash point at least 20 degrees Celsius higher than a flash point of said solvent alone, a flash point higher than 150° C., or no detectable flash point at all, wherein said ion-conducting polymer is selected from the group consisting of poly(perfluoro sulfonic acid), sulfonated poly(ether ketone), sulfonated styrene-butadiene copolymers, sulfonated poly chloro-trifluoroethylene (PCTFE), sulfonated perfluoroethylene-propylene copolymer (FEP), sulfonated ethylene-chlorotrifluoroethylene copolymer (ECTFE), sulfonated polyvinylidenefluoride (PVDF), sulfonated copolymers of polyvinylidenefluoride with hexafluoropropene and tetrafluoroethylene, sulfonated copolymers of ethylene and tetrafluoroethylene (ETFE), sulfonated polybenzimidazole (PBI), their chemical derivatives, copolymers, blends and combinations thereof;
(b) forming the cathode material into a quasi-solid cathode, wherein said forming includes deforming the cathode material into an electrode shape without interrupting said 3D network of electron-conducting pathways such that the cathode maintains an electrical conductivity no less than 10 −6 S/cm;
(c) forming an anode
(d) forming an alkali metal-sulfur cell by combining the quasi-solid cathode and the anode, and
(e) wherein said alkali metal-sulfur cell is a sodium-ion sulfur cell, and said anode contains an anode active material containing an alkali intercalation compound selected from carbon black, amorphous carbon, activated carbon, hard carbon, soft carbon, templated carbon, hollow carbon nanowires, hollow carbon sphere, titanates, NaTi 2 (PO 4 ) 3 , Na 2 Ti 3 O 7 , Na 2 TP, Na x TiO 2 (x=0.2 to 1.0), Na 2 C 8 H 4 O 4 , carboxylate based materials, C 8 H 6 O 4 , C 8 H 5 NaO 4 , C 8 Na 2 F 4 O 4 , C 10 H 2 Na 4 O 8 , C 14 H 4 O 6 , C 14 H 4 Na 4 O 8 , or a combination thereof.