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;
a cathode;
a first separator disposed on the anode;
a second separator disposed on the cathode; and
an interlayer disposed at least partially between the first separator and the second separator, the interlayer extending beyond at least one edge of the second separator.
2 . The electrochemical cell of claim 1 , wherein the portion of the interlayer extending beyond the edge of the second separator is configured to contact the cathode if the cathode becomes laterally misaligned with the anode.
3 . 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(OH) 3 , or ZrO 2 .
4 . The electrochemical cell of claim 1 , wherein the interlayer and the first separator extend beyond the edge of the second separator by an extension distance.
5 . The electrochemical cell of claim 4 , wherein the extension distance is between about 100 μm and about 2 mm.
6 . The electrochemical cell of claim 1 , further comprising:
an interlayer tab coupled to the interlayer.
7 . The electrochemical cell of claim 6 , further comprising:
a first film coupled to an anode current collector on which the anode is disposed and contacting the interlayer tab; and
a second film coupled to a cathode current collector on which the cathode is disposed and contacting the interlayer tab, wherein the first film and the second film collectively form a pouch.
8 . The electrochemical cell of claim 1 , wherein the interlayer includes an electronically conductive material.
9 . The electrochemical cell of claim 1 , wherein the interlayer includes at least one of activated carbon, hard carbon, soft carbon, conductive carbon particles, carbon black, graphitic carbon, carbon fibers, carbon microfibers, vapor-grown carbon fibers (VGCF), fullerenic carbons including “buckyballs”, carbon nanotubes (CNTs), multiwall carbon nanotubes (MWNTs), single wall carbon nanotubes (SWNTs), graphene, graphene sheets or aggregates of graphene sheets, or materials comprising fullerenic fragments.
10 . The electrochemical cell of claim 1 , wherein the cathode includes at least one of LFP, LMFP, LCO, LMO, LNO, or NMC.
11 . The electrochemical cell of claim 1 , wherein the edge of the second separator is a first edge and the extension distance is a first extension distance, the interlayer and the first separator extending beyond a second edge of the second separator by a second extension distance, the second edge opposite the first edge.
12 . 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 at least partially between the second separator and the third separator.
13 . An electrochemical cell, comprising:
an anode;
a cathode;
a first separator disposed on the anode;
a second separator disposed on the cathode;
an interlayer disposed at least partially between the first separator and the second separator, the interlayer including a first portion coupled to both the first separator and the second separator and a second portion coupled to one of the first separator or the second separator.
14 . The electrochemical cell of claim 13 , wherein the interlayer includes a third portion coupled to the other of the first separator or the second separator.
15 . The electrochemical cell of claim 13 , further comprising:
an interlayer tab coupled to the interlayer.
16 . The electrochemical cell of claim 15 , further comprising:
a first film coupled to an anode current collector on which the anode is disposed and contacting the interlayer tab; and
a second film coupled to a cathode current collector on which the cathode is disposed and contacting the interlayer tab, wherein the first film and the second film collectively form a pouch.
17 . The electrochemical cell of claim 13 , wherein the interlayer includes at least one of activated carbon, hard carbon, soft carbon, conductive carbon particles, carbon black, graphitic carbon, carbon fibers, carbon microfibers, vapor-grown carbon fibers (VGCF), fullerenic carbons including “buckyballs”, carbon nanotubes (CNTs), multiwall carbon nanotubes (MWNTs), single wall carbon nanotubes (SWNTs), graphene, graphene sheets or aggregates of graphene sheets, or materials comprising fullerenic fragments.
18 . The electrochemical cell of claim 13 , wherein the anode includes at least one of graphite, lithium metal, or silicon.
19 . The electrochemical cell of claim 13 , 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(OH) 3 , or ZrO 2 .
20 . The electrochemical cell of claim 13 , wherein the cathode includes at least one of LFP, LMFP, LCO, LMO, LNO, or NMC.
21 . The electrochemical cell of claim 13 , wherein the interlayer is a first interlayer, the electrochemical cell further comprising:
a third separator; and
a second interlayer disposed at least partially between the second separator and the third separator.
22 . An electrochemical cell, comprising:
a first electrode;
a second electrode;
a first separator coupled to the first electrode, the first separator having a first length;
a second separator coupled to the second electrode, the second separator having a second length longer than the first length; and
an interlayer coupled to the first separator and the second separator, the interlayer extending beyond a first outer edge of the first separator and beyond a second outer edge of the first separator, the second edge opposite the first edge.
23 . The electrochemical cell of claim 22 , wherein the second electrode includes at least one of LFP, LMFP, LCO, LMO, LNO, or NMC.
24 . The electrochemical cell of claim 22 , wherein the first electrode includes at least one of graphite, lithium metal, or silicon.
25 . The electrochemical cell of claim 22 , wherein the first electrode includes lithium metal.
26 . The electrochemical cell of claim 22 , wherein the interlayer 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.
27 . The electrochemical cell of claim 22 , wherein the interlayer is a first interlayer, the electrochemical cell further comprising:
a third separator; and
a second interlayer disposed at least partially between the second separator and the third separator.
28 . The electrochemical cell of claim 22 , wherein the interlayer extends beyond a first outer edge of the first separator by a first extension distance and beyond a second outer edge of the first separator by a second extension distance, the first extension distance between about 100 μm and about 2 mm, the second extension distance between about 100 μm and about 2 mm.
29 . The electrochemical cell of claim 22 , further comprising:
a first electrode tab electrically coupled to the first electrode;
a second electrode tab electrically coupled to the second electrode; and
an interlayer tab electrically coupled to the interlayer, wherein the first electrode tab, the second electrode tab, and the interlayer tab each extend outside of a casing in which the electrochemical cell is disposed.
30 . The electrochemical cell of claim 22 , 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.