Lithium-oxygen batteries incorporating lithium superoxide
A composition includes LiO 2 , reduced graphene oxide, and a metal catalyst or residue thereof.
1. A composition comprising LiO 2 , reduced graphene oxide, and a metal catalyst or residue thereof.
2. The composition of claim 1 , which is free of Li 2 O 2 and Li 2 O.
3. The composition of claim 1 , wherein the metal catalyst comprises a metal that forms an intermetallic phase with lithium, and the intermetallic phase has an orthorhombic structure.
4. The composition of claim 3 , wherein the intermetallic phase is Ir 3 Li.
5. The composition of claim 1 , wherein the metal catalyst comprises Ir, Ru, Pt, or Pd.
6. The composition of claim 1 , wherein the metal catalyst comprises Ir.
7. The composition of claim 1 , wherein the LiO 2 is crystalline LiO 2 .
8. An electrochemical cell comprising:
an anode comprising lithium metal;
a cathode comprising LiO 2 , reduced graphene oxide, and a metal catalyst or residue thereof, wherein the cathode is substantially free of Li 2 O 2 and Li 2 O; and
an electrolyte.
9. The electrochemical cell of claim 8 , wherein the electrolyte comprises a solvent and a lithium salt.
10. The electrochemical cell of claim 9 , wherein the solvent comprises an ether-based solvent, a fluorinated ether-based solvent, an oligo(ethylene oxide) solvent, or a mixture of any two or more thereof.
11. The electrochemical cell of claim 9 , wherein the lithium salt comprises LiCF 3 CO 2 , LiC 2 F 5 CO 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiPF 6 , LiPF 2 (C 2 O 4 ) 2 , LiPF 4 C 2 O 4 , LiCF 3 SO 3 , LiN(CF 3 SO 2 ) 2 , LiC(CF 3 SO 2 ) 3 , LiN(SO 2 C 2 F 5 ) 2 ), lithium alkyl fluorophosphates, Li(C 2 O 4 ) 2 , LiBF 2 C 2 O 4 , Li 2 B 12 X 12-p H p , Li 2 B 10 X 10-y H y , or a mixture of any two or more lithium salts, where X is OH, F, Cl, or Br; p is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; and y is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.
12. An electrochemical cell comprising:
an anode comprising lithium metal;
a cathode comprising LiO 2 , reduced graphene oxide, and a metal catalyst or residue thereof; and
an electrolyte.
13. The electrochemical cell of claim 12 , wherein the electrochemical cell is a closed electrochemical cell.
14. A process of forming LiO 2 , the process comprising:
providing an electrochemical cell, the electrochemical cell comprising a porous oxygen carbon cathode, a lithium anode, a current collector, and an electrolyte; and
discharging the electrochemical cell to form a discharge product;
wherein:
the discharge product comprises LiO 2 ;
the porous oxygen carbon cathode comprises reduced graphene oxide and a catalyst; and
the discharge product is free of Li 2 O and Li 2 O 2 .
15. The process of claim 14 , wherein the LiO 2 exhibits a Raman absorption peak at 1123 cm −1 , and x-ray diffraction (2θ) peaks of 2.530, 2.590, 2.710, and 3.000 while being void of (2θ) peaks of 2.321, 2.464, 2.851, 3.400, 4.020, and 4.747.