Silicon-based energy storage devices with cyclic organosilicon containing electrolyte additives
Electrolytes and electrolyte additives for energy storage devices comprising a cyclic organosilicon compound are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a cyclic organosilicon compound.
1. An energy storage device comprising:
a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode;
a separator between the first electrode and the second electrode;
an electrolyte; and
at least one electrolyte additive comprising a compound selected from Formulae (A), (B), (C), (D) and (E):
wherein:
each R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 is independently selected from the group consisting of —H, C1-C4 alkyl, C2-C4 alkenyl, and
wherein members of the group may be optionally substituted by —F, —CF 3 , and —CN groups;
A is NR a ;
each R a is individually either —H or —SiR′R″; and
each R′ and R″ is independently selected from the group consisting of —H, —F and an alkyl; wherein
in Formula (A), at least one R 1 , R 2 , R 3 , R 4 , R 5 and R 6 is a C2-C4 alkenyl substituted by —F, —CF 3 , or —CN;
in Formula (B), at least one R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 is a C2-C4 alkenyl substituted by —F, —CF 3 , or —CN;
in Formula (C), at least one R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 is a C2-C4 alkenyl substituted by —F, —CF 3 , or —CN;
in Formula (D), at least one R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 and R 12 is a C2-C4 alkenyl substituted by —F, —CF 3 , or —CN; and
in Formula (E), at least one R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 and R 14 is a C2-C4 alkenyl substituted by —F, —CF 3 , or —CN.
2. The energy storage device of claim 1 , wherein the second electrode is a Si-dominant electrode.
3. The energy storage device of claim 1 , wherein the second electrode comprises a self-supporting composite material film.
4. The energy storage device of claim 3 , wherein the composite material film comprises:
greater than 0% and less than about 90% by weight of silicon particles, and
greater than 0% and less than about 90% by weight of one or more types of carbon phases, wherein at least one of the one or more types of carbon phases is a substantially continuous phase that holds the composite material film together such that the silicon particles are distributed throughout the composite material film.
5. The energy storage device of claim 1 , wherein the electrolyte further comprises fluoroethylene carbonate (FEC).
6. The energy storage device of claim 5 , wherein the electrolyte is substantially free of non-fluorine containing cyclic carbonate.