Symmetrical and unsymmetrical organosilicon molecules and electrolyte compositions and electrochemical devices containing them
View Patent ↗Described are organosilicon electrolyte compositions having improved thermostability and electrochemical properties and electrochemical devices that contain the organosilicon electrolyte compositions.
1. An electrolyte composition comprising at least one organosilicon and a lithium-containing salt, wherein the organosilicon is:
wherein R 1 , R 2 , R 3 , and R 4 are the same or different and are independently selected from the group consisting of C 1 -C 6 linear, branched, or cyclic alkyl, and each “n” is independently an integer of from 1 to 15; and
wherein the composition undergoes no more than about 10% thermal decomposition at a temperature of about 100° C.
2. The electrolyte composition of claim 1 , wherein the composition undergoes no more than about 20% thermal decomposition at a temperature of about 150° C.
3. The electrolyte composition of claim 1 , wherein the lithium containing salt is selected from the group consisting of LiTFSI, LiPF 6 , LiBOB, LiClO 4 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiTaF 6 , LiNbF 6 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , Li(FSO 2 ) 2 N, Li(CF 3 SO 2 ) 2 N, Li(C 2 F 5 SO 2 ) 2 N, Li(CF 3 SO 2 ) 3 C, LiBF 3 (C 2 F 5 ), LiB(C 2 O 4 ) 2 , LiB(C 6 F 5 ) 4 , LiPF 3 (C 2 F 5 ) 3 , ½Li 2 B 12 F 12 , and combinations thereof.
4. The electrolyte composition of claim 3 , wherein the lithium-containing salt is present in a concentration of from about 0.1 M to about 3.5 M.
5. The electrolyte composition of claim 3 , wherein the composition undergoes no more than about 20% thermal decomposition at a temperature of about 150° C.
6. The electrolyte composition of claim 1 , wherein the lithium-containing salt is selected from the group consisting of LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiTaF 6 , and LiNbF 6 .
7. The electrolyte composition of claim 6 , wherein the lithium-containing salt is present in a concentration of from about 0.1 M to about 3.5 M.
8. The electrolyte composition of claim 7 , wherein the composition undergoes no more than about 20% thermal decomposition at a temperature of about 150° C.
9. The electrolyte composition of claim 1 , further comprising a co-solvent.
10. The electrolyte composition of claim 9 , wherein the co-solvent comprises a carbonate moiety (—O—C(═O)—O—).
11. The electrolyte composition of claim 1 ,
wherein when the organosilicon includes a Si—O bond, and is formulated with 20 wt % ethylene carbonate co-solvent and 1M LiPF 6 , it has a potential of at least about 5 V when current exceeds 1 mA/cm 2 in a three-electrode cell comprising a platinum working electrode, a lithium counter-electrode, and a Li/Li + reference electrode; and
wherein when the organosilicon does not include a Si—O bond, and is formulated with 20 wt % ethylene carbonate co-solvent and 1M LiPF 6 , it has a potential of at least about 6 V when current exceeds 1 mA/cm 2 in a three-electrode cell comprising a platinum working electrode, a lithium counter-electrode, and a Li/Li + reference electrode.
12. An electrochemical device comprising an electrolyte composition as recited in claim 1 .