Electrochemical device having an electrolyte that includes a tetrasiloxane
The electrochemical device has an electrolyte that includes one or more tetrasiloxanes. The tetrasiloxanes have a backbone with two central silicons and two terminal silicons. A first one of the silicons is linked to a side chain that includes a poly(alkylene oxide) moiety. A second one of the silicons is linked to a side chain that includes a poly(alkylene oxide) moiety or to a side chain that includes a cyclic carbonate moiety. When each of the central silicons is linked to a side chain that includes a poly(alkylene oxide) moiety, each of the central silicons is directly linked to the poly(alkylene oxide) moiety.
1 . An electrochemical device, comprising:
an electrolyte including a tetrasiloxane having a backbone with two central silicons and two terminal silicons:
a first one of the silicons being linked to a side chain that includes a poly(alkylene oxide) moiety;
a second one of the silicons being linked to a side chain that includes a poly(alkylene oxide) moiety or to a side chain that includes a cyclic carbonate moiety; and
each of the central silicons being directly liked to the poly(alkylene oxide) moiety when each of the central silicons is linked to a side chain that includes a poly(alkylene oxide) moiety.
2 . The device of claim 1 , wherein a third one of the silicons and a fourth one of the silicons are each linked to side chains that each exclude a poly(alkylene oxide) moiety.
3 . The device of claim 1 , wherein a third one of the silicons and a fourth one of the silicons are each linked to side chains that each exclude a cyclic carbonate moiety.
4 . The device of claim 1 , wherein a third one of the silicons and a fourth one of the silicons are each linked to side chains that each exclude both a cyclic carbonate moiety and a poly(alkylene oxide) moiety.
5 . The device of claim 1 , wherein the first silicon is a terminal silicon and the second silicon is a terminal silicon.
6 . The device of claim 5 , wherein the first silicon is linked directly to an oxygen included in the poly(alkylene oxide) moiety.
7 . The device of claim 5 , wherein the side chain linked to the first silicon includes an organic spacer positioned between the first silicon and the poly(alkylene oxide) moiety.
8 . The device of claim 5 , wherein the tetrasiloxane is represented by:
wherein R 1 is an alkyl group; R 2 is an alkyl group; R 3 is an alkyl group or an aryl group; R 4 is an alkyl group or an aryl group; R 5 is an alkyl group or an aryl group; R 6 is an alkyl group or an aryl group; R 7 is nil or a spacer, R 8 is nil or a spacer; R 9 is a hydrogen, an alkyl group or an aryl group; R 10 is a hydrogen, an alkyl group or an aryl group; R 11 is an alkyl group or an aryl group; and R 12 is an alkyl group or an aryl group; x is 1 to 12 and y is 1 to 12.
9 . The device of claim 8 , wherein R 1 ; R 2 ; R 3 ; R 4 ; R 5 ; R 6 ; R 11 ; and R 12 are each methyl groups.
10 . The device of claim 8 , wherein R 7 and R 8 are each nil.
11 . The device of claim 8 , wherein R 7 and R 8 are each an organic spacer.
12 . The device of claim 5 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12 and m is 1 to 12.
13 . The device of claim 5 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12 and m is 1 to 12.
14 . The device of claim 1 , wherein the first silicon is a central silicon and the second silicon is a central silicon.
15 . The device of claim 14 , wherein the tetrasiloxane is represented by:
wherein:
R 20 is an alkyl group or an aryl group; R 21 is an alkyl group or an aryl group; R 22 is represented by formula II-A; R 23 is represented by formula II-B or formula II-C; and each Z is an alkyl or an aryl group;
formula II-A:
wherein R 24 is an organic spacer or nil; R 25 is hydrogen, alkyl, or aryl; R 26 is alkyl or aryl; and p is 1 to 12;
formula II-B:
wherein R 28 is hydrogen, alkyl or aryl; R 29 is alkyl or aryl; and q is 1 to 12;
formula II-C:
wherein R 30 is an organic spacer; and r is 1 or 2.
16 . The device of claim 14 , wherein the second silicon is linked to a side chain that includes a cyclic carbonate moiety.
17 . The device of claim 16 , wherein an organic spacer links the poly(alkylene oxide) moiety to the first silicon.
18 . The device of claim 16 , wherein the first silicon is linked directly to the poly(alkylene oxide) moiety.
19 . The device of claim 16 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12.
20 . The device of claim 16 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12.
21 . The device of claim 14 , wherein the second silicon is linked to a side chain that includes a poly(alkylene oxide) moiety.
22 . The device of claim 1 , wherein the electrolyte includes an alkali metal salt.
23 . The device of claim 22 , wherein a concentration of the alkali metal salt in the electrolyte is in a range of 0.3 M to 2.0 M.
24 . The device of claim 1 , wherein the electrolyte includes an organoborate salt.
25 . The device of claim 1 , further comprising:
at least one cathode, at least one porous separator and at least one anode.
26 . The device of claim 25 , wherein the cathode includes a lithium metal oxide and the anode includes at least one material selected from a group consisting of carbon and lithium metal.
27 . The device of claim 25 , wherein the anode includes a lithium metal and the electrolyte includes an organoborate salt.
28 . The device of claim 1 , wherein the electrolyte is a liquid.
29 . The device of claim 1 , wherein the electrolyte is a solid or a gel.
30 . The device of claim 1 , wherein the electrolyte includes the tetrasiloxane entrapped within a network polymer.
31 . The device of claim 30 , wherein the network polymer is a product of polymerizing a dialkyl acrylate, a dimethacrylate, a dialkyl methacrylate or a diallyl terminated compound.
32 . The device of claim 1 , wherein the electrolyte includes a solid polymer.
33 . The device of claim 32 , wherein the solid polymer is selected from a group consisting of: polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVdF), poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinyl acetate), polystyrene, poly(ethylene oxide) (PEO).
34 . The device of claim 1 , wherein the electrochemical device includes an anode and the electrolyte includes an additive selected to form a passivation layer on the electrode.
35 . The device of claim 1 , wherein the electrochemical device includes an anode and the electrolyte includes an additive selected such that the additive is reduced at the surface of the anode so as to form a passivation layer on the anode.
36 . The device of claim 1 , wherein the electrochemical device includes an anode and the electrolyte includes an additive selected so as to polymerize such that a passivation layer is formed on the anode.
37 . The device of claim 1 , wherein the electrolyte includes at least one additive selected from the group consisting of: vinyl carbonate, vinyl ethylene carbonate, ethylene sulfite, 1,3 dimethyl butadiene, styrene carbonate, aromatic carbonates, vinyl pyrrole, vinyl piperazine, vinyl piperidine, vinyl pyridine, and mixtures thereof.
38 . The device of claim 1 , wherein the electrolyte includes one or more additives selected from the group consisting of vinyl carbonate (VC) and vinyl ethylene carbonate (VEC).
39 . The device of claim 1 , wherein the tetrasiloxane is more than 50 wt % of the electrolyte.
40 . An electrochemical device, comprising:
an electrolyte including a tetrasiloxane selected from the group of tetrasiloxanes represented by formula I and formula II:
formula I:
wherein R 1 is an alkyl group; R 2 is an alkyl group; R 3 is an alkyl group or an aryl group; R 4 is an alkyl group or an aryl group; R 5 is an alkyl group or an aryl group; R 6 is an alkyl group or an aryl group; R 7 is nil or a spacer, R 8 is nil or are each a spacer; R 9 is a hydrogen, an alkyl group or an aryl group; R 10 is a hydrogen, an alkyl group or an aryl group; R 11 is an alkyl group or an aryl group; and R 12 is an alkyl group or an aryl group; x is 1 to 12 and y is 1 to 12; and
formula II:
wherein: R 20 is an alkyl group or an aryl group; R 21 is an alkyl group or an aryl group; R 22 is represented by formula II-A; R 23 is represented by formula II-B or formula II-C; and each Z is an alkyl or an aryl group;
formula II-A:
wherein R 24 is an organic spacer or nil; R 25 is hydrogen, alkyl, or aryl; R 26 is alkyl or aryl; and p is 1 to 12;
formula II-B:
wherein R 28 is hydrogen, alkyl or aryl; R 29 is alkyl or aryl; and q is 1 to 12;
formula II-C:
wherein R 30 is an organic spacer; and r is 1 or 2.
41 . The device of claim 40 , wherein the tetrasiloxane is selected from the group consisting of tetrasiloxanes represented by formula I.
42 . The device of claim 40 , wherein the tetrasiloxane is selected from the group consisting of tetrasiloxanes represented by formula II.
43 . A method of forming an electrochemical device, comprising:
generating an electrolyte including a tetrasiloxane having a backbone with two central silicons and two terminal silicons,
a first one of the silicons being linked to a side chain that includes a poly(alkylene oxide) moiety,
a second one of the silicons being linked to a side chain that includes a poly(alkylene oxide) moiety or to a side chain that includes a cyclic carbonate moiety, and
each of the central silicons being directly to the poly(alkylene oxide) moiety when each of the central silicons is linked to a side chain that includes a poly(alkylene oxide) moiety; and
activating at least one anode and at least one cathode with the electrolyte.
44 . The method of claim 43 , wherein the remaining two of the silicons are linked to side chains that each exclude cyclic carbonate moieties.
45 . The method of claim 43 , wherein the first silicon is a terminal silicon and the second silicon is a terminal silicon.
46 . The method of claim 45 , wherein the tetrasiloxane is represented by:
wherein R 1 is an alkyl group; R 2 is an alkyl group; R 3 is an alkyl group or an aryl group; R 4 is an alkyl group or an aryl group; R 5 is an alkyl group or an aryl group; R 6 is an alkyl group or an aryl group; R 7 is nil or a spacer, R 8 is nil or are each a spacer; R 9 is a hydrogen, an alkyl group or an aryl group; R 10 is a hydrogen, an alkyl group or an aryl group; R 11 is an alkyl group or an aryl group; and R 12 is an alkyl group or an aryl group; x is 1 to 12 and y is 1 to 12.
47 . The method of claim 45 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12 and m is 1 to 12.
48 . The method of claim 45 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12 and m is 1 to 12.
49 . The method of claim 43 , wherein the first silicon is a central silicon and the second silicon is a central silicon.
50 . The method of claim 49 , wherein the tetrasiloxane is represented by:
wherein:
R 20 is an alkyl group or an aryl group; R 21 is an alkyl group or an aryl group; R 22 is represented by formula II-A; R 23 is represented by formula II-B or formula II-C; and each Z is an alkyl or an aryl group;
formula II-A:
wherein R 24 is an organic spacer or nil; R 25 is hydrogen, alkyl, or aryl; R 26 is alkyl or aryl; and p is 1 to 12;
formula II-B:
wherein R 28 is hydrogen, alkyl or aryl; R 29 is alkyl or aryl; and q is 1 to 12;
formula II-C:
wherein R 30 is an organic spacer; and r is 1 or 2.
51 . The method of claim 49 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12.
52 . The method of claim 49 , wherein the tetrasiloxane is represented by:
wherein n is 1 to 12.