Rechargeable magnesium battery
This invention generally relates to electrochemical cells utilizing magnesium anodes, new solutions and intercalation cathodes. The present invention is a new rechargeable magnesium battery based on magnesium metal as an anode material, a modified Chevrel phase as an intercalation cathode for magnesium ions and new electrolyte solution from which magnesium can be deposited reversibly, which have a very wide electrochemical window. The Chevrel phase compound is represented by the formula Mo6S8-YSeY in which y is higher than 0 and lower than 2 or by the formula MXMo6S8 in which M is selected from the group comprising of copper (Cu), nickel (Ni), silver (Ag) and/or any other transition metal; further wherein x is higher than 0 and lower than 2.
1. An electrolyte for use in an electrochemical cell, said electrolyte comprising:
(a) at least one magnesium-aluminum complex represented by the formulae (MgR 2 )—(AlCl 3 - n R n ) y in which R is selected from the group consisting of methyl, ethyl, butyl and phenyl, y is greater than 1 and lower than 5, and n is equal or greater than 0 and lower than 3; and
(b) at least one inert salt selected from the group consisting of tetrabutylammonium-chloride and LiX in which X is selected from the group consisting of chlorine (Cl) and bromine (Br), forming a magnesium-aluminum complex salt;
wherein said complex salt is dissolved in a solvent selected from the group consisting of polyethers, glymes and tetra-hydrofuran (THF), forming a magnesium-aluminum complex solution;
wherein the magnesium of said magnesium-aluminum complex is characterized by 100% reversible deposition-dissolution from said complex solution such that said deposition-dissolution of said magnesium has an electrochemical window of at least 3V.
2. A magnesium rechargeable battery comprising:
(a) at least one intercalation cathode comprising a Chevrel phase compound;
(b) at least one magnesium anode; and
(c) at least one non-aqueous electrolyte solution comprising the magnesium-aluminum complex solution of claim 1 .
3. The magnesium rechargeable battery according to claim 2 , wherein said Chevrel phase compound is represented by the formula M X Mo 6 S 8 in which M is selected from the group consisting of copper, nickel, and silver and x is greater than about 0 and lower than about 2.
4. The magnesium rechargeable battery according to claim 2 , wherein said solution further comprises polyethylene-oxide or polyvinylidene di-fluoride (PVdF) from about 70% to 90% wt, and at least one of tetra-glyme, tri-glyme, glyme and tetra-hydrofuran (THF).
5. The magnesium rechargeable battery according to claim 2 , further comprising a polypropylene or glass fibers separator located between the electrodes.
6. The magnesium rechargeable battery according to claim 2 , wherein the concentration of said (MgR 2 )—(AlCl 3 - n R n ) y is greater than about 0.45M and lower than about 0.55M and wherein the concentration of said LiX is greater than about 0.2M and lower than about 0.3M.
7. A method for producing a magnesium rechargeable battery according to claim 2 , said method comprising steps of:
a. providing (i) at least one intercalation cathode comprising a Chevrel phase compound; (ii) at least one magnesium anode; and (iii) at least one nonaqueous electrolyte solution comprising the magnesium-aluminum complex solution; and,
b. providing at least one of electrical and electrochemical communication between said cathode, said anode and said electrolyte;
wherein said Chevrel phase compound represented by the formulae Mo 6 S 8-Y S eY in which y is greater than 0 and lower than about 2.
8. A method for producing a magnesium rechargeable battery according to claim 3 , said method comprising the steps of:
a. providing (i) at least one intercalation cathode comprising a Chevrel phase compound; (ii) at least one magnesium anode; and (iii) at least one non-aqueous electrolyte solution comprising the magnesium-aluminum complex solution; and
b. providing electrical and electrochemical communication between said cathode, said anode and said electrolyte; wherein said Chevrel phase compound represented by the formulae M x Mo 6 S 8 in which M is selected from the group comprising of copper (Cu), Nickel (Ni) silver (Ag) and x is greater than about 0 and lower than about 2.
9. A magnesium rechargeable battery comprising an electrochemical cell, the electrochemical cell comprising the electrolyte according to claim 1 , further comprising at least one intercalation cathode comprising a Chevrel phase compound.
10. The magnesium rechargeable battery according to claim 9 , wherein said Chevrel phase compound is represented by the formula Mo 6 S 8-Y S eY in which Y is greater than 0 and lower than 2.
11. The magnesium rechargeable battery according to claim 9 , wherein said Chevrel phase compound is represented by the formula M X Mo 6 S 8 , in which M is selected from the group consisting of copper, nickel and silver and x is greater than 0 and lower than 2.
12. The magnesium rechargeable battery according to claim 10 , further comprising a polypropylene or glass fibers separator located between said cathode and an anode.
13. The magnesium rechargeable battery according to claim 9 , wherein said Chevrel phase compound is represented by the formulae M X Mo 6 S 8 in which M is selected from the group consisting of copper (Cu), nickel (Ni) and silver (Ag) and x is greater than 0 and lower than 2.
14. An electrolyte for use in an electrochemical cell, said electrolyte comprising:
(a) at least one magnesium-aluminum complex represented by the formula (RMgCl) x —(AlCl 3 - n R n ) y , in which R is selected from the group consisting of methyl, ethyl, butyl and phenyl, y is greater than 1 and lower than 5, n is equal or greater than 0 and lower than 3, and x is greater than 1 and lower than 3; and
(b) at least one inert salt selected from the group consisting of tetrabutylammonium-chloride and LiX, in which X is selected from the group consisting of chlorine (Cl) and bromine (Br), forming a magnesium-aluminum complex salt;
wherein said electrolyte complex salt is dissolved in a solvent selected from the group consisting of polyethers, glymes and tetra-hydrofuran (THF), forming a magnesium-aluminum complex solution;
wherein the magnesium of said magnesium-aluminum complex is characterized by 100% reversible deposition-dissolution from said complex solution such that said deposition-dissolution of said magnesium has an electrochemical window of at least 3V.
15. The magnesium rechargeable battery of claim 2 , wherein said Chevrel phase compound is represented by the formulae Mo 6 S 8-Y Se Y , in which Y is greater than 0 and lower than about 2.