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. An electrochemical cell, comprising:
an anode disposed on an anode current collector;
a cathode disposed on a cathode current collector;
a first separator and a second separator disposed between the anode and the cathode, the first separator having a first length, and the second separator having a second length longer than the first length; and
an interlayer including a conductive material disposed on the second separator, such that a portion of the interlayer is not coupled to the first separator.
2. The electrochemical cell of claim 1 , further comprising:
an interlayer tab coupled to the portion of the interlayer that is not coupled to the first separator.
3. The electrochemical cell of claim 2 , further comprising:
a first film coupled to the anode current collector and contacting the interlayer tab; and
a second film coupled to the anode current collector and contacting the interlayer tab,
wherein the first film and the second film collectively form a pouch.
4. The electrochemical cell of claim 1 , wherein the first separator is disposed on the anode and the second separator is disposed on the cathode.
5. The electrochemical cell of claim 1 , wherein the cathode includes at least one of LFP, LMFP, LCO, LMO, LNO, or NMC.
6. The electrochemical cell of claim 1 , wherein the conductive material includes Li (1-x) NMC, where x is between 0 and 1.
7. The electrochemical cell of claim 1 , wherein the anode includes at least one of graphite, lithium metal, or silicon.
8. The electrochemical cell of claim 1 , wherein the conductive material includes at least one of: a solid state electrolyte; a carbonaceous material including carbon black, CNT, or CNF; or LFP, LMFP, LNO, LMO, LCO, or NMC.
9. The electrochemical cell of claim 1 , wherein the interlayer is a first interlayer, the electrochemical cell further comprising:
a third separator; and
a second interlayer disposed between the second separator and the third separator.
10. The electrochemical cell of claim 1 , further comprising:
a casing that contains the anode, the anode current collector, the cathode, the cathode current collector, the first separator, the second separator, and the interlayer.
11. The electrochemical cell of claim 10 , further comprising:
an anode tab electrically coupled to the anode;
a cathode tab electrically coupled to the cathode; and
an interlayer tab electrically coupled to the interlayer,
wherein the anode tab, the cathode tab, and the interlayer tab each extend outside of the casing.
12. The electrochemical cell of claim 1 , wherein the electrochemical cell is wound into a cylindrical shape such that the portion of the interlayer not coupled to the first separator faces outward.
13. The electrochemical cell of claim 1 , wherein at least one of the first separator or the second separator includes polyvinylidene fluoride (PVDF), styrene-butadiene (SBR), carboxymethyl cellulose (CMC), polyethylene oxides (PEO), polytetrafluoroethylene (PTFE), (perfluoroalkoxy alkanes) PFA, polyacrylonitrile (PAN), poly(acrylic acid) PAA, Poly Olefin, polysulfone (PES), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polybenzimidazole (PBI), polyamide-imides (PAI), polyimide (PI), polyether ether ketone (PEEK), ultraviolet (UV) curable resin, urethane/epoxy acrylate, Al 2 O 3 , boehmite, MgO, Al(HO) 3 , or ZrO 2 .
14. An electrochemical cell stack, comprising:
an interlayer assembly, comprising:
a first separator;
a second separator; and
an interlayer material disposed between the first separator and the second separator, the interlayer material including a conductive material;
an anode;
a first cathode; and
a second cathode,
wherein the interlayer assembly is wound such that a first portion of the interlayer assembly is disposed between the anode and the first cathode and a second portion of the interlayer assembly is disposed between the anode and the second cathode.
15. The electrochemical cell stack of claim 14 , wherein the interlayer material is coated on the second separator and a portion of the second separator extends beyond the first separator such that a portion of the interlayer material is not coupled to the first separator.
16. The electrochemical cell stack of claim 14 , wherein the anode is a first anode, the electrochemical cell stack further comprising:
a second anode, wherein a third portion of the interlayer assembly is disposed between the second cathode and the second anode.
17. The electrochemical cell stack of claim 16 , further comprising:
a third cathode, wherein a fourth portion of the interlayer assembly is disposed between the second anode and the third cathode.
18. The electrochemical cell stack of claim 17 , further comprising:
a third anode, wherein a fifth portion of the interlayer assembly is disposed between the third cathode and the third anode.
19. The electrochemical cell stack of claim 18 , further comprising:
a fourth cathode, wherein a sixth portion of the interlayer assembly is disposed between the third anode and the fourth cathode.
20. The electrochemical cell stack of claim 19 , wherein a seventh portion of the interlayer is disposed around the first anode, the first cathode, the second anode, the second cathode, the third anode, the third cathode, and the fourth cathode, such that the seventh portion of the interlayer assembly envelops the first portion, the second portion, the third portion, the fourth portion, the fifth portion, and the sixth portion of the interlayer assembly.
21. The electrochemical cell stack of claim 15 , further comprising an interlayer tab extending from the portion of the interlayer material that is not coupled to the first separator.
22. The method of claim 14 , wherein the conductive material includes a solid state electrolyte.
23. The method of claim 14 , wherein the conductive material includes Li (1-x) NMC, where x is between 0 and 1.
24. The method of claim 14 , wherein the interlayer material includes at least one: of a carbonaceous material including carbon black, CNF, or CNF; or LFP, LMFP, LMO, LNO, LCO, or NMC.
25. The method of claim 14 , wherein at least one of the first cathode or the second cathode includes at least one of LFP, LNO, LCO, LMO, LNO, LMFP, or NMC.
26. An electrochemical cell, comprising:
an anode disposed on an anode current collector;
a cathode disposed on a cathode current collector;
a first separator and a second separator disposed between the anode and the cathode, the first separator and the second separator disposed in an offset arrangement; and
an interlayer including conductive material disposed on the second separator such that a first portion of the interlayer is exposed and not coupled to the first separator and a second portion of the interlayer is exposed and not coupled to the second separator.
27. The electrochemical cell of claim 26 , further comprising:
an interlayer tab coupled to at least one of the first portion or the second portion.
28. The electrochemical cell of claim 26 , wherein the first separator is disposed on the anode and the second separator is disposed on the cathode.
29. The electrochemical cell of claim 26 , wherein the cathode includes at least one of LFP, LMFP, LNO, LCO, LMO or NMC.
30. The electrochemical cell of claim 26 , wherein the interlayer includes at least one of: a carbonaceous material including carbon black, CNT, or CNF; or LFP, LMFP, LNO, LMO, LCO, NMC, or Li (1-x) NMC, where x is between 0 and 1.