Silicon-based energy storage devices with cyclic carbonate containing electrolyte additives
Electrolytes and electrolyte additives for use in energy storage devices, comprising cyclic carbonate compounds.
1. An energy storage device comprising:
a first electrode and a second electrode, wherein one or both 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 of Formula (A):
wherein:
R 1 is alkenyloxy-alkyl; and each R 2 , R 3 , and R 4 is independently an —H or a C1-C8 alkyl substituted by F, where R 2 , and one or both of R 3 and R 4 is C1-C8 alkyl substituted by F; and wherein the electrolyte contains fluoroethylene carbonate (FEC) and is substantially free of non-fluorine containing cyclic carbonate.
2. The energy storage device of claim 1 , wherein:
R 2 and one or both of R 3 and R 4 is —CF 3 .
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.