Systems and methods for minimizing and preventing dendrite formation in electrochemical cells
Embodiments described herein relate to electrochemical cells with dendrite prevention mechanisms. In some aspects, an electrochemical cell can include an anode disposed on an anode current collector, a cathode disposed on a cathode current collector, the cathode having a first thickness at a proximal end of the cathode and a second thickness at a distal end of the cathode, the second thickness greater than the first thickness, a first separator disposed on the anode, a second separator disposed on the cathode, an interlayer disposed between the first separator and the second separator, the interlayer including electroactive material and having a proximal end and a distal end, and a power source electrically connected to the proximal end of the cathode and the proximal end of the interlayer, the power source configured to maintain a voltage difference between the cathode and the interlayer below a threshold value.
1. A method of operating an electrochemical cell, the electrochemical cell including an anode disposed on an anode current collector, a cathode disposed on a cathode current collector, a first separator, a second separator, and an interlayer disposed between the first separator and the second separator, the method comprising:
measuring a voltage between the anode and the interlayer, the interlayer including a conductive material disposed on at least one of the first separator or the second separator; and
transferring electrical energy from the cathode to the interlayer via an external energy source, such that the voltage is maintained above a threshold voltage.
2. The method of claim 1 , wherein transferring electrical energy from the cathode to the interlayer is done by a battery management system (BMS).
3. The method of claim 1 , further comprising:
in response to the voltage decreasing below the threshold value:
closing a circuit between the anode and the cathode; and
discharging the electrochemical cell.
4. The method of claim 1 , wherein the threshold voltage is 0.1 V.
5. The method of claim 1 , wherein the voltage is a first voltage, the interlayer is a first interlayer, the electrochemical cell further includes a third separator disposed between the second separator and the cathode and a second interlayer disposed between the second separator and the third separator, the method further comprising:
measuring a second voltage between the anode and the second interlayer.
6. The method of claim 1 , wherein the interlayer includes a solid state electrolyte.
7. The method of claim 1 , wherein the interlayer includes Li(1−x) xNMC and x is between 0 and 1.
8. The method of claim 1 , wherein the interlayer includes at least one of a carbonaceous material, LFP, LCO, or NMC.
9. The method of claim 1 , wherein the cathode includes at least one of LFP, LCO, or NMC.
10. The method of claim 1 , wherein the voltage is measured by a voltage measurement device connected to an anode tab extending from the anode current collector and an interlayer tab extending from the interlayer.
11. The method of claim 10 , wherein the interlayer tab extends beyond the first separator and the second separator in a first direction and extends in a second direction opposite the first direction to a point less than about 10 mm from an edge of the first separator.
12. An electrochemical cell, comprising:
an anode disposed on an anode current collector;
a cathode disposed on a cathode current collector;
a first separator disposed on the anode;
a second separator disposed on the cathode;
an interlayer including a conductive material disposed between the first separator and the second separator; and
a power source electrically coupled to the cathode and the interlayer, the power source configured to transfer electrical energy from the cathode to the interlayer to maintain a voltage between the anode and the interlayer above a threshold value.
13. The electrochemical cell of claim 12 , wherein the threshold value is 0.1 V.
14. The electrochemical cell of claim 12 , wherein the cathode includes at least one of LFP, LNO, or NMC.
15. The electrochemical cell of claim 12 , wherein the interlayer includes Li(1−x) xNMC and x between 0 and 1.
16. The electrochemical cell of claim 12 , wherein the anode includes at least one of graphite, lithium metal, or silicon.
17. The electrochemical cell of claim 12 , wherein the interlayer includes at least one of a carbonaceous material, LFP, LCO, or NMC.
18. The electrochemical cell of claim 12 , further comprising:
a tab extending from the interlayer, the tab extending beyond the first separator and the second separator.
19. The electrochemical cell of claim 18 , wherein the tab extends beyond the first separator and the second separator in a first direction and extends in a second direction opposite the first direction to a point less than about 10 mm from an edge of the first separator.
20. The electrochemical cell of claim 19 , further comprising:
a first film coupled to the anode current collector and contacting the tab; and
a second film coupled to the anode current collector and contacting the tab,
wherein the first film and the second film collectively form a pouch.
21. The electrochemical cell of claim 19 , further comprising:
a coupling member at least partially encircling the first separator, the second separator, and the tab.
22. The electrochemical cell of claim 21 , wherein the coupling member at least partially encircles the first film and the second film.
23. A method of operating an electrochemical cell, the electrochemical cell including an anode disposed on an anode current collector, a cathode disposed on a cathode current collector, a first separator, a second separator, and an interlayer disposed between the first separator and the second separator, the method comprising:
transferring electrical energy from the cathode to the interlayer via a closed circuit during operation of the electrochemical cell;
measuring a voltage between the anode and the interlayer, the interlayer including a conductive material disposed on at least one of the first separator or the second separator; and
controlling the transfer of electrical energy from the cathode to the interlayer to maintain the voltage above a threshold value.
24. The method of claim 23 , wherein the threshold value is 0.1 V.
25. The method of claim 23 , wherein transferring the electrical energy from the cathode to the interlayer is done by a battery management system (BMS).
26. The method of claim 23 , further comprising:
in response to the voltage decreasing below the threshold value:
closing a circuit between the anode and the cathode; and
discharging the electrochemical cell.
27. The method of claim 23 , wherein the voltage is a first voltage, the interlayer is a first interlayer, the electrochemical cell further includes a third separator disposed between the second separator and the cathode and a second interlayer disposed between the second separator and the third separator, the method further comprising:
measuring a second voltage between the anode and the second interlayer.
28. The method of claim 23 , wherein the interlayer includes a solid state electrolyte.
29. The method of claim 23 , wherein the interlayer includes Li(1−x) xNMC and x is between 0 and 1.
30. The method of claim 23 , wherein the interlayer includes at least one of a carbonaceous material, LFP, LCO, or NMC.