Silicon-based energy storage devices with fluorinated polymer containing electrolyte additives
Electrolytes and electrolyte additives for energy storage devices comprising fluorinated polymers.
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 of Formula (D):
wherein:
each R 7 , and R 8 is independently selected from the group consisting of —H, —OH, alkyl, alkenyl, nitrile, carboxyl, —Cl, —F, —CF 3 , and —OCF 3 ;
each C, D, and E is independently selected from the group consisting of
each optionally substituted
by —F, —CF 3 , or —CH 3 ;
each Ra, Rb, and Rc is independently selected from the group consisting of —CF 3 ,
each optionally substituted by —F; and
each s, t, and u is independently selected from an integer from 1-3.
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.