Low temperature lithium production
A method and electrolysis cell for producing lithium metal at a low temperature. The method includes combining (i) phenyl trihaloalkyl sulfone and (ii) an organic cation bis(trihaloalkylsulfonyl)imide or organic cation bis(trihalosulfonyl)imidic acid in a weight ratio of (i) to (ii) about 10:90 to about 60:40 to provide a non-aqueous electrolyte composition. A lithium compound selected from the group consisting of LiOH, Li 2 O and Li 2 CO 3 is dissolved in the electrolyte composition to provide a soluble lithium ion species in the electrolyte composition. Power is applied to the electrolyte composition to form lithium metal on a cathode of an electrolysis cell. The lithium metal is separated from the cathode has a purity of at least about 95 wt. %.
1. A method of producing lithium metal in an electrolysis cell, the method comprising the steps of:
combining (i) phenyl trihaloalkyl sulfone and (ii) an organic cation bis(trihaloalkylsulfonyl)imide or organic cation bis(trihalosulfonyl)imidic acid in a weight ratio of (i) to (ii) of about 10:90 to about 60:40 to provide a non-aqueous electrolyte composition,
dissolving a lithium compound selected from the group consisting of LiOH, Li 2 O and Li 2 CO 3 in the electrolyte composition to provide a soluble lithium ion species in the electrolyte composition,
applying power to the electrolysis cell to form lithium metal on a cathode of an electrolysis cell,
separating lithium metal from the cathode, wherein the lithium metal on the cathode has a purity of at least about 95 wt. %.
2. The method of claim 1 , wherein the electrolyte composition further comprises a zwitterion or internal salt compound.
3. The method of claim 2 , wherein the zwitterion comprises a (carboxyalkyl)trialkyl ammonium compound.
4. The method of claim 1 , wherein heat is applied to the electrolyte composition at a temperature ranging from about 30° to less than about 100° C.
5. The method of claim 1 , wherein the electrolysis cell comprises an anode compartment, a cathode compartment and a separator between the anode compartment and the cathode compartment.
6. The method of claim 5 , wherein a weight ratio of soluble lithium ion species to electrolyte composition in the cathode compartment ranges from about 10:60 to about 10:25.
7. The method of claim 6 , wherein the separator is selected from the group consisting of a fritted glass separator, a microporous membrane, and a salt bridge.
8. The method of claim 1 , wherein the organic cation is selected from the group consisting of a phosphonium ion, a sulfonium ion, an ammonium ion, an imidazolium ion, a piperidinium ion, a pyridinium ion and a pyrrolidinium ion.
9. The method of claim 1 , wherein the halo ion is a fluoride ion of components (i) and (ii).
10. The method of claim 1 , wherein the alkyl group is a methyl group of components (i) and (ii).
11. The method of claim 1 , wherein power is applied to the anode and cathode at a current density ranging from about 0.1 mA/cm 2 to about 0.83 mA/cm 2 .
12. An electrolysis cell for producing lithium metal at a temperature below about 100° C. comprising:
a cathode compartment comprising a cathode,
an anode compartment comprising an anode,
a separator between the anode compartment and the cathode compartment
a non-aqueous electrolyte composition in the anode and cathode compartments comprising (i) phenyl trihaloalkyl sulfone and (ii) an organic cation bis(trihaloalkylsulfonyl)-imide or organic cation bis(trihalosulfonyl)imidic acid in a weight ratio of (i) to (ii) of about 10:90 to about 60:40, wherein the electrolyte composition further comprises a lithium compound selected from the group consisting of LiOH, Li 2 O and Li 2 CO 3 dissolved in the electrolyte composition,
whereby power applied to the anode and cathode forms lithium metal on the cathode of the electrolysis cell with a lithium metal purity of greater than 95 wt. %.
13. The electrolysis cell of claim 12 , wherein a weight ratio of soluble lithium ion species to electrolyte composition in the cathode compartment ranges from about 10:60 to about 10:25.
14. The electrolysis cell of claim 12 , wherein the electrolyte composition further comprises a (carboxyalkyl)trialkyl ammonium compound.
15. The electrolysis cell of claim 12 , wherein the separator is selected from the group consisting of a fritted glass separator, a microporous membrane, and a salt bridge.
16. The electrolysis cell of claim 12 , wherein the organic cation is selected from the group consisting of a phosphonium ion, a sulfonium ion, an ammonium ion, an imidazolium ion, a piperidinium ion, a pyridinium ion and a pyrrolidinium ion.
17. The electrolysis cell of claim 12 , wherein the halo ion is a fluoride ion of components (i) and (ii).
18. The electrolysis cell of claim 12 , wherein the alkyl group is a methyl group of components (i) and (ii).