Ionic gel electrolyte, energy storage devices, and methods of manufacture thereof
An electrochemical cell includes solid-state, printable anode layer, cathode layer and non-aqueous gel electrolyte layer coupled to the anode layer and cathode layer. The electrolyte layer provides physical separation between the anode layer and the cathode layer, and comprises a composition configured to provide ionic communication between the anode layer and cathode layer by facilitating transmission of multivalent ions between the anode layer and the cathode layer.
1. An electrochemical cell, comprising:
an anode;
a cathode; and
a printed gel electrolyte between the anode and the cathode, wherein the electrolyte is configured to provide ionic communication between the anode and the cathode to facilitate transmission of multivalent ions between the anode and the cathode, wherein the multivalent ions are selected from at least one of zinc, aluminum, magnesium and yttrium, and wherein the electrochemical cell displays substantially no capacity degradation after at least 70 cycles.
2. The electrochemical cell of claim 1 , wherein the gel electrolyte comprises a polymer into which an ionic liquid and an electrolyte salt are imbibed.
3. The electrochemical cell of claim 2 , wherein the ionic liquid comprises cations selected from the group consisting of: imidazolium, pyrrolidinium, ammonium, pyridinium, piperidinium, phosphonium, and sulfonium.
4. The electrochemical cell of claim 2 , wherein the ionic liquid comprises anions selected from the group consisting of: chlorides, tetrafluoroborate (BF 4 −), trifluoroacetate (CF 3 CO 2 −), trifluoromethansulfonate (CF 3 SO 3 −), hexafluorophosphate (PF 6 −), bis(trifluoromethylsulfonyl)amide (NTf 2 −), and bis(fluorosulfonyl)imide (N(SO 2 F) 2 −).
5. The electrochemical cell of claim 2 , wherein the salt releases cations selected from the group consisting of zinc, aluminum, magnesium and yttrium.
6. The electrochemical cell of claim 2 , wherein the salt releases anions selected from the group consisting of chlorides, tetrafluoroborate (BF4−), trifluoroacetate (CF 3 CO 2 −), trifluoromethansulfonate (CF 3 SO 3 −), hexafluorophosphate (PF 6 −), bis(trifluoromethylsulfonyl)amide (NTf 2 −), and bis(fluorosulfonyl)imide (N(SO 2 F) 2 −).
7. The electrochemical cell of claim 2 , wherein the polymer comprises at least one polymer selected from the group consisting of poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride) hexaflourophosphate (PVDF-HFP), polyvinyl alcohol (PVA), poly(ethylene oxide) (PEO), poly(acrylo-nitrile) (PAN), and poly(methyl methacrylate) (PMMA), epoxy derivatives, and silicone derivatives.
8. The electrochemical cell of claim 2 , wherein the gel electrolyte comprises a weight percentage of the ionic liquid to the polymer not exceeding 75 wt %.
9. The electrochemical cell of claim 1 , wherein the printed gel electrolyte has an ionic conductivity between 0.3 mS/cm and 2.7 mS/cm.
10. The electrochemical cell of claim 1 , wherein the anode comprises at least one of zinc, aluminum, magnesium and yttrium.
11. The electrochemical cell of claim 10 , wherein the anode comprises zinc.
12. The electrochemical cell of claim 1 , wherein the cathode comprises a metal oxide.
13. The electrochemical cell of claim 12 , wherein the metal oxide comprises a component selected from the group consisting of vanadium pentoxide (V 2 O 5 ), manganese dioxide (MnO 2 ), cobalt oxide (Co x O y ), titanium oxide (Ti x O y ), and lead oxide (Pb x O y ).
14. The electrochemical cell of claim 13 , wherein the metal oxide is manganese dioxide (MnO 2 ).
15. The electrochemical cell of claim 1 , wherein the gel electrolyte is configured to maintain a leakage current density of less than 25 pA/cm 2 after being exposed to a temperature of 20° C. for a period of greater than 1 week.
16. The electrochemical cell of claim 1 , wherein the gel electrolyte is configured to maintain a leakage current density of less than 50 pA/cm 2 after being exposed to a temperature of between 20° C. and 45° C. for a period of greater than 1 day.
17. The electrochemical cell of claim 1 , wherein the electrochemical cell is configured to output a current density of between 0.001 mA/cm 2 to 100 mA/cm 2 .
18. The electrochemical cell of claim 1 , wherein the gel electrolyte is a flexible electrolyte gel.
19. The electrochemical cell of claim 1 , wherein the electrochemical cell is not hermetically sealed.
20. The electrochemical cell of claim 1 , wherein the electrochemical cell is configured to be conformable to a non-planar substrate without damage.