Silicon-based energy storage devices with silicon containing electrolyte additives
Electrolytes and electrolyte additives for energy storage devices comprising a silicon 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 silicon 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), (E), (F), (G) and (H):
X is an alkali metal salt;
each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is independently selected from the group consisting of a C1-C10 alkyl, a C1-C5 alkoxy, a C2-C8 alkenyl, a C2-C8 heteroalkenyl with at least one O heteroatom, cycloalkenyl, —F, aryl, amine,
wherein members of the group may be optionally substituted by —F, alkyl, carbonyl, cycloalkyl, aryl, cycloalkenyl, —CN,
groups; wherein n is 1, 2, 3 or 4;
each of R a , R b , R c , R d , R e , R f , R g , R h and R i is independently selected from the group consisting of hydrogen, a C1-C4 alkyl, C1-C4 alkoxy, aryl and a C2-C4 alkenyl; and
wherein E is
2. The energy storage device of claim 1 , wherein each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is independently selected from the group consisting of C1-C10 alkyl, —NH 2 ,
wherein members of the group may be optionally substituted by —F, alkyl, carbonyl,
cycloalkyl, aryl or cycloalkenyl groups; and wherein p is 1, 2, 3, 4, 5, 6, 7, or 8.
3. The energy storage device of claim 1 , wherein the second electrode is a Si-dominant electrode.
4. The energy storage device of claim 1 , wherein the second electrode comprises a self-supporting composite material film.
5. The energy storage device of claim 4 , 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.
6. The energy storage device of claim 1 , wherein the electrolyte further comprises fluoroethylene carbonate (FEC).
7. The energy storage device of claim 6 , wherein the electrolyte is substantially free of non-fluorine containing cyclic carbonate.