Pulse plating of lithium material in electrochemical devices
The present invention is directed to battery system and operation thereof. In an embodiment, lithium material is plated onto the anode region of a lithium secondary battery cell by a pulsed current. The pulse current may have both positive and negative polarity. One of the polarities causes lithium material to plate onto the anode region, and the opposite polarity causes lithium dendrites to be removed. There are other embodiments as well.
1. A lithium battery device comprising:
a lithiated cathode region having a first surface and a second surface;
a cathode current collector overlying the first surface, the cathode current collector overlaying the first surface of the lithiated cathode region;
a solid electrolyte region having a third surface and a fourth surface, the third surface interfacing the second surface, the solid electrolyte region being characterized by a ionic conductivity of at least 10 −7 S/cm;
an anode region having a fifth surface and a sixth surface, the fifth surface interfacing the fourth surface; and
an anode current collector overlaying the sixth surface, wherein the anode current collector comprises a layer of Sn metal;
wherein the anode region is formed by in-situ application of a plurality of current pulses between the cathode current collector and the anode current collector;
wherein the solid electrolyte region comprises a layer of lithium-stuffed garnet solid electrolyte.
2. The device of claim 1 further comprising a dendrite layer within the proximity of the anode region, the plurality of current pulses being configured to remove at least a part of the dendrite layer.
3. The device of claim 1 wherein the anode region is characterized by a variable thickness, the variable thickness being associated with a state of charge of the lithium battery device.
4. The device of claim 1 wherein the anode region is characterized by a variable thickness, the variable thickness being associated with the first pulse current.
5. The device of claim 1 wherein the anode region is characterized by a variable thickness, the variable thickness being associated with a number of life cycles of the lithium battery device.
6. The device of claim 1 wherein the anode region is characterized by a variable thickness and further comprises a sensor for monitoring a state of charge.