Anode compositions for lithium secondary batteries
View Patent ↗A lithium secondary battery comprising a cathode, an anode, and a separator-electrolyte assembly or electrolyte layer disposed between the cathode and the anode, wherein the anode comprises: (a) an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein the filaments have a transverse dimension less than 500 nm; and (b) a foil of lithium or lithium alloy as an anode active material. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life.
1. A lithium secondary battery selected from a lithium metal battery or lithium-air battery, comprising a cathode, an anode, and a separator-electrolyte assembly or electrolyte layer disposed between said cathode and said anode, wherein said anode of said lithium metal battery or lithium-air battery comprises an anode active material consisting of:
a. an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein said filaments have a transverse dimension less than 500 nm and said filaments are electro-spun nano fibers, vapor-grown carbon or graphite nano fibers, carbon or graphite whiskers, carbon nano-tubes, nano-scaled graphene platelets, metal nano wires, or a combination thereof, and wherein lithium ions are deposited on surfaces of said filaments during a charge of said lithium metal battery or lithium-air battery, and lithium ions are released from said filament surfaces during a discharge of said lithium metal battery or lithium-air battery and these filaments prevent dendrite formation; and
b. lithium or lithium alloy foil as an anode active material of said lithium metal battery or lithium-air battery.
2. The lithium secondary battery of claim 1 wherein said integrated nano-structure is disposed between said lithium or lithium alloy foil and said separator-electrolyte assembly or electrolyte layer.
3. The lithium secondary battery of claim 1 wherein said lithium or lithium alloy foil is disposed between said integrated nano-structure and said separator-electrolyte assembly or electrolyte layer.
4. The lithium secondary battery of claim 1 wherein said filaments have a transverse dimension smaller than 100 nm.
5. The lithium secondary battery of claim 1 wherein said filaments comprise a fiber selected from the group consisting of an electrically conductive electro-spun polymer fiber, electro-spun polymer nanocomposite fiber comprising a conductive filler, nano carbon fiber obtained from carbonization of an electro-spun polymer fiber, electro-spun pitch fiber, and combinations thereof.
6. The lithium secondary battery of claim 1 wherein said filaments comprise nano-scaled graphene platelets with a thickness less than 10 nm.
7. The lithium secondary battery of claim 1 wherein said filaments comprise single-layer graphene.
8. The lithium secondary battery of claim 1 wherein said integrated structure comprises a gradient structure.
9. The lithium secondary battery of claim 1 , wherein said nano-filaments are bonded by a binder material selected from a polymer, coal tar pitch, petroleum pitch, meso-phase pitch, coke, or a derivative thereof.
10. The lithium secondary battery according to claim 1 , wherein said cathode comprises a cathode active material selected from the group consisting of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, a non-lithiated oxide of a transition metal, lithium iron phosphate, lithium vanadium phosphate, lithium manganese phosphate, a non-lithiated transition metal phosphate, a chalcogen compound, and combinations thereof.
11. The lithium secondary battery according to claim 1 , wherein said cathode comprises a non-lithiated cathode active material.
12. The lithium secondary battery according to claim 1 , wherein said cathode comprises sulfur, sulfur-containing molecule, sulfur-containing compound, sulfur-carbon polymer, or a combination thereof.
13. The lithium secondary battery according to claim 1 , wherein said cathode comprises (a) an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising pores, wherein said filaments have a transverse dimension less than 500 nm; and (b) a cathode active material bonded to or in physical contact with said integrated nano-structure.
14. The lithium secondary battery according to claim 13 , wherein said cathode active material comprises sulfur, a sulfur-containing molecule, a sulfur-containing compound, a sulfur-carbon polymer, or a combination thereof.
15. The lithium secondary battery according to claim 13 , wherein said cathode active material contains a coating bonded to at least one of said filaments.
16. The lithium secondary battery according to claim 1 , wherein said electrolyte is selected from the group consisting of polymer electrolyte, polymer gel electrolyte, solid-state electrolyte, composite electrolyte, soft matter phase electrolyte, and combinations thereof.
17. The lithium secondary battery according to claim 1 , wherein said electrolyte is selected from the group of solid-state electrolytes consisting of solid ionic conductors based on a LiM 2 (PO 4 ) 3 structure, where M is a metal, lithium aluminum germanium phosphates represented by Li 1+x Al x Ge 2−x PO 4 ) 3 , where x=0.1-0.9, glass-ceramic solid electrolytes, and combinations thereof.
18. The lithium secondary battery as defined in claim 1 , wherein said battery provides a reversible specific capacity of no less than 500 mAh per gram of the total battery weight including anode, cathode, electrolyte, and separator components together.
19. The lithium secondary battery as defined in claim 1 , wherein said battery provides a specific capacity of no less than 700 mAh per gram of the total battery weight including anode, cathode, electrolyte, and separator components together.
20. The lithium secondary battery of claim 1 , which is a lithium-air battery and wherein said cathode is an air cathode.
21. The lithium-air battery of claim 20 wherein said filaments have a transverse dimension smaller than 100 nm.
22. The lithium-air battery of claim 20 wherein said filaments comprise an electrically conductive material selected from the group consisting of electro-spun nano fibers, vapor-grown carbon or graphite nano fibers, carbon or graphite whiskers, carbon nano-tubes, nano-scaled graphene platelets, metal nano wires, and combinations thereof.
23. The lithium-air battery of claim 20 wherein said filaments comprise a fiber selected from the group consisting of an electrically conductive electro-spun polymer fiber, electro-spun polymer nanocomposite fiber comprising a conductive filler, nano carbon fiber obtained from carbonization of an electro-spun polymer fiber, electro-spun pitch fiber, and combinations thereof.
24. The lithium-air battery of claim 20 wherein said filaments comprise nano-scaled graphene platelets with a thickness less than 10 nm.
25. The lithium-air battery of claim 20 wherein said filaments comprise single-layer graphene.
26. The lithium-air battery of claim 20 wherein said integrated nano-structure comprises a gradient structure.
27. The lithium-air battery as defined in claim 20 , wherein said nano-filaments are bonded by a binder material selected from a polymer, coal tar pitch, petroleum pitch, meso-phase pitch, coke, or a derivative thereof.
28. The lithium-air battery according to claim 20 , wherein said air cathode comprises an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein said filaments in said air cathode have a transverse dimension less than 500 nm.
29. The lithium-air battery according to claim 28 , wherein said air cathode further comprises a catalyst coated on a surface of said filaments and said catalyst serves to catalyze a cathode reaction of reducing lithium oxide to lithium ions and oxygen during a battery re-charging operation.
30. The lithium-air battery according to claim 20 , wherein said electrolyte is selected from the group of solid-state electrolytes consisting of solid ionic conductors based on a LiM 2 (PO 4 ) 3 structure, where M is a metal, lithium aluminum germanium phosphates represented by Li 1+x Al x Ge 2−x PO 4 ) 3 , where x=0.1-0.9, glass-ceramic solid electrolytes, and combinations thereof.
31. The lithium-air battery according to claim 29 , wherein said electrolyte is selected from the group of solid-state electrolytes consisting of solid ionic conductors based on a LiM 2 (PO 4 ) 3 structure, where M is a metal, lithium aluminum germanium phosphates represented by Li 1+x Al x Ge 2−x PO 4 ) 3 , where x=0.1-0.9, glass-ceramic solid electrolytes, and combinations thereof.