FUNCTIONALIZED CROWN ETHERS FOR LITHIUM-ION BATTERIES
An electrolyte containing functionalized crown ethers suitable for use in electrochemical energy storage devices useful for reducing battery resistance, increasing cycle life, and improving high-temperature performance is disclosed.
1 . An electrochemical energy storage device electrolyte comprising:
an aprotic organic solvent;
a metal salt; and
at least one compound according to the formula I, II or III
wherein:
n is an integer ranging from 2 to 8;
X is independently oxygen or sulfur; and
R is independently a halogen, oxygen or sulfur atom further bonded to C 1 -C 12 substituted or unsubstituted alkyl groups, or C 6 -C 14 aryl group, C 1 -C 12 substituted or unsubstituted alkyl group, or C 6 -C 14 aryl group,
wherein any hydrogen atom can be replaced with or carbon atom can be unsubstituted or can be substituted with an epoxide, halogen, alkyl, alkoxy, perfluorinated alkyl, silyl, siloxy, silane, sulfoxide, amide, azo, ether, and thioether group or combination thereof.
2 . The electrolyte of claim 1 , wherein the at least one compound according to the formula I, II or III is one of the following structures:
3 . The electrolyte of claim 1 , wherein the at least one compound according to formula I, II or III is present in a concentration from 0.01 wt. % to 10 wt. % of the electrolyte.
4 . The electrolyte of claim 1 , wherein the aprotic organic solvent comprises an open-chain or cyclic carbonate, carboxylic acid ester, nitrite, ether, sulfone, ketone, lactone, dioxolane, glyme, crown ether, siloxane, phosphoric acid ester, phosphite, mono- or polyphosphazene or mixture thereof.
5 . The electrolyte of claim 1 , wherein the aprotic organic solvent is present in a concentration of from 50 wt. % to 90 wt. % of the electrolyte.
6 . The electrolyte of claim 1 , wherein the cation of the metal salt is an alkali metal. 7 The electrolyte of claim 6 , wherein the alkali metal is lithium or sodium.
8 . The electrolyte of claim 1 , wherein the metal salt is present in a concentration of from 10 wt. % to 30 wt. % in the electrolyte.
9 . The electrolyte of claim 1 , further comprising at least one additive.
10 . The electrolyte of claim 9 , wherein the at least one additive comprises a sulfur-containing compound, phosphorus-containing compound, boron-containing compound, silicon-containing compound, fluorine-containing compound, nitrogen-containing compound, compound containing at least one unsaturated carbon-carbon bond, carboxylic acid anhydride, epoxide, or a mixture thereof.
11 . The electrolyte of claim 10 , wherein the at least one additive is present in a concentration of from 0.01 wt. % to 10 wt. % in the electrolyte.
12 . An electrochemical energy storage device comprising:
a cathode;
an anode;
an electrolyte according to claim 1 ; and
a separator.
13 . The device of claim 12 , wherein the cathode comprises a lithium metal oxide, spinel, olivine, carbon-coated olivine, vanadium oxide, lithium peroxide, sulfur, lithium polysulfide, a lithium carbon monofluoride or mixture thereof.
14 . The device of claim 13 , wherein the lithium metal oxide is LiCoO 2 , LiNiO 2 , LiNi x Co y Met z O 2 , LiMn 0.5 Ni 0.5 O 2 , LiMn 0.1 Co 0.1 Ni 0.8 O 2 , LiMn 0.2 Co 0.2 Ni 0.6 O 2 , LiMn 0.3 Co 0.2 Ni 0.5 O 2 , LiMn 0.33 Co 0.33 Ni 0.33 O 2 , LiMn 2 O 4 , LiFeO 2 , Li 1+x′ Ni α Mn β Co γ Met′ δ O 2−z′ F z′ , or A n′ B 2 (XO 4 ) 3 , wherein Met is Al, Mg, Ti, B, Ga, Si, Mn or Co; Met′ is Mg, Zn, Al, Ga, B, Zr or Ti; A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu or Zn; B is Ti, V, Cr, Fe or Zr; X is P, S, Si, W or Mo; and wherein 0≤x≤0.3, 0≤y≤0.5, 0≤z≤0.5, 0≤x′≤0.4, 0≤α≤1, 0≤β≤1, 0≤γ≤1, 0≤δ≤0.4, 0≤z′≤0.4 and 0≤h′≤3.
15 . The device of claim 12 , wherein the anode comprises lithium metal, graphitic material, amorphous carbon, Li 4 Ti 5 O 12 , tin alloy, silicon, silicon alloy, intermetallic compound, or mixture thereof.
16 . The device of claim 15 , wherein the anode is a composite anode comprising an active material silicon or silicon alloy and a conductive polymer coating around the active material.
17 . The device of claim 16 , wherein the conductive polymer is polyacrylonitrile (PAN).
18 . The device of claim 12 , wherein the separator comprises a porous separator separating the anode and cathode from each other.
19 . The device of claim 18 , wherein the porous separator comprises an electron beam-treated micro-porous polyolefin separator or a microporous polymer film comprising nylon, cellulose, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polypropylene, polyethylene, polybutene, or co-polymer or blend of any two or more such polymers.
20 . The device of claim 12 , wherein the aprotic organic solvent comprises an open-chain or cyclic carbonate, carboxylic acid ester, nitrite, ether, sulfone, ketone, lactone, dioxolane, glyme, crown ether, siloxane, phosphoric acid ester, phosphite, mono- or polyphosphazene or mixture thereof.
21 . The device of claim 12 , wherein the aprotic organic solvent is present in a concentration of from 50 wt. % to 90 wt. % in the electrolyte.
22 . The device of claim 12 , wherein the cation of the metal salt is an alkali metal.
23 . The device of claim 22 , wherein the alkali metal is lithium or sodium.
24 . The device of claim 12 , wherein the metal salt is present in a concentration of from 10 wt. % to 30 wt. % in the electrolyte.
25 . The device of claim 12 , wherein the electrolyte further comprises at least one additive.
26 . The device of claim 25 , wherein the at least one additive comprises a sulfur-containing compound, phosphorus-containing compound, boron-containing compound, silicon-containing compound, fluorine-containing compound, nitrogen-containing compound, compound containing at least one unsaturated carbon-carbon bond, carboxylic acid anhydride, epoxide, or mixture thereof.
27 . The device of claim 25 , wherein the at least one additive is present in a concentration of from 0.01 wt. % to 10 wt. % in the electrolyte.