Anode, cell, and method of stabilizing an anode for use in a lithium ion electrochemical cell
A battery comprises an anode, a cathode, a first reference electrode, and a second reference electrode. The battery also include an electrolyte between each of the anode, cathode, first reference electrode, and second reference electrode.
1. A method for conditioning an anode electrode in an electrochemical cell, the method comprising:
providing an electrochemical cell comprising a silicon-comprising anode electrode, a cathode electrode, an electrolyte, and at least one micro-reference electrode, wherein the cathode electrode over anode electrode capacity ratio is between 1 and 1.3;
conditioning the anode electrode in the electrochemical cell in a half cell mode by passing a current between the anode electrode and the cathode electrode while controlling the potential between the anode electrode and the at least one micro-reference electrode to avoid Li plating until the anode electrode reaches a stabilized state; and
switching the electrochemical cell to a regular full cell mode and applying a CC-CV charging/CC discharging protocol.
2. The method of claim 1 , wherein the at least one micro-reference electrode is connected to an electronic circuit controlling the potential between the anode electrode and the at least one micro-reference electrode and the potential between the cathode electrode and at least one micro-reference electrode.
3. The method of claim 2 , wherein the conditioning further comprises controlling the potential between the anode electrode and the at least one micro-reference electrode within the range from about 0.01 to 700 mV during the half cell mode.
4. The method of claim 1 further comprising, after switching to full cell mode, monitoring during cycling the potential between the anode electrode and the at least one micro-reference electrode and the potential of the cathode electrode and the at least one micro-reference electrode via a Battery Management System (BMS) to avoid Li-plating of the anode and to avoid over charging of the cathode.
5. The method of claim 1 further comprising, after switching to full cell mode, applying the charging/discharging protocol via a programmable Battery Management System (BMS), wherein the protocol is based on the anode and the cathode potential profiles based on the electrodes chemistries.
6. The method of claim 1 , wherein the silicon in the silicon comprising anode electrode is in the form of Si nanowires directly grown on or deposited on graphite powders.
7. The method of claim 1 , wherein the silicon in the silicon comprising anode electrode is in the form of Si nanopowders directly grown or deposited on graphite powders.
8. The method of claim 1 , wherein the silicon in the silicon comprising anode electrode is in the form of Si thin films directly grown or deposited on graphite powders.
9. The method of claim 1 , wherein the at least one micro-reference electrode is placed aside to or in a slot within the anode electrode.
10. The method of claim 1 , wherein the at least one micro-reference electrode comprises lithium metal or a lithium-containing metal oxide in contact with the electrolyte.
11. The method of claim 10 , wherein the at least one micro-reference electrode comprises lithium deposited in situ in the full electrochemical cell or during the cell fabrication.
12. The method of claim 11 , wherein the at least one micro-reference electrode comprises lithium re-deposited in situ in the full electrochemical cell after a period of normal full cell mode cycling to avoid or remedy degradation of the micro-reference electrode.
13. The method of claim 1 , wherein the at least one micro-reference electrode comprises any of: LTO, LFP, LCO, NCA, NCM, LMO or Li.