Method for alkaliating electrodes
The present invention relates to a method for lithiation of an intercalation-based anode or a non-reactive plating-capable foil or a reactive alloy capable anode, whereby utilization of said lithiated intercalation-based anode or a plating-capable foil or reactive alloy capable anode in a rechargeable battery or electrochemical cell results in an increased amount of lithium available for cycling, and an improved reversible capacity during charge and discharge.
1. A method for pre-lithiation of a material comprising the steps of:
(a) providing a material;
(b) providing a bath comprising gamma-butyrolactone and at least one dissolved lithium halide salt, wherein said bath contacts the material and wherein a dry gas blanket covers said bath;
(c) providing an electrolytic field plate comprising an inert conductive material wherein said field plate establishes a field between the material and the field plate;
(d) applying a reducing current to the material and an oxidizing current to the field plate, wherein lithium ions from the bath lithiate into the material;
(e) rinsing the lithiated material produced by step (d); and
(f) assembling a rechargeable battery with the lithiated material.
2. The method of claim 1 , wherein the material is an anode active material selected from carbon, coke, graphite, tin, tin oxide, silicon, silicon oxide, aluminum, lithium-active metals, alloying metal materials, composites and mixtures thereof.
3. The method of claim 1 , wherein the halogen of the dissolved lithium halide salt is selected from ionic F − , Cl − , Br − , I − and mixtures thereof.
4. The method of claim 1 , wherein the dissolved lithium halide salt is LiCl.
5. The method of claim 1 , wherein the dissolved lithium halide salt is LiBr.
6. The method of claim 1 , wherein the dissolved lithium halide salt is LiF.
7. The method of claim 1 , wherein the electrolytic field plate is selected from platinum, gold, glassy carbon, and graphite.
8. The method of claim 1 , wherein evolving gas generated at the field plate is captured by a reflux unit, a membrane contactor, a gas scrubber, or combinations thereof.
9. The method of claim 1 , comprising one or more inline heaters.
10. The method of claim 9 , wherein said inline heaters heat the gamma-butyrolactone and dissolved lithium halide salt to a temperature of between 30° C. and 65° C.
11. The method of claim 10 , wherein said temperature is about 40° C.
12. The method of claim 1 , wherein a separate immersion bath is used to rinse the material in a solvent while holding the field plate in a reducing current mode.
13. A method of claim 1 , wherein lithium halide salt is recovered periodically by distillation of the used gamma-butyrolactone and subsequent rinsing of the salt in a light non-solvating fluid.
14. The method of claim 1 , wherein the process is continuous.
15. The method of claim 1 , wherein the gamma-butyrolactone contains an additive to facilitate high quality SEI formation.
16. The method of claim 15 , wherein the additive is vinylene carbonate.
17. The method of claim 1 , wherein a dissolved gas is added.
18. The method of claim 17 , in which the dissolved gas is carbon dioxide.