Abstract: Lithium-ion electrochemical cells are provided that include a positive electrode that includes a lithium metal oxide or a lithium metal phosphate, a negative electrode capable of intercalating or alloying with lithium, and an electrolyte that includes an additive. The additive includes a multifunctional anion that has the formula, X—SO2—Rf—SO2—Y, wherein X and Y are, independently, either O— or RfSO2N—, Rf is a straight or branched fluoroalkyl moiety having from 1 to 6 carbon atoms, and can, optionally, contain one or more in-chain heteroatoms, wherein Rf is a straight or branched chain or cyclic fluoroalkylene having from 1 to 10 carbon atoms and can, optionally, contain one or more in-chain heteroatoms, and wherein both Rf and Rf have a maximum of 20% non-fluorine substituents. The provided additives can improve the performance, hydrolytic stability, and thermal stability of the provided electrochemical cells.

Abstract: A cathode composition is provided. The composition includes particles having the following formula Li[Lix(NiaMnbCoc)1-x]O2, where 0<x<0.3, 0<a<1, 0<b<1, 0<c<1, a+b+c=1, a/b?1. The composition further includes a coating composition having the formula LifCog[PO4]1-f-g (0?f<1, 0?g<1). The coating composition is disposed on an outer surface of the particles.

Abstract: Lithium-ion electrochemical cells are provided that include a positive electrode that includes a lithium metal oxide or a lithium metal phosphate, a negative electrode capable of intercalating or alloying with lithium, and an electrolyte that includes an additive. The additive includes a multifunctional anion that has the formula, X—SO2—Rf?—SO2—Y, wherein X and Y are, independently, either O— or RfSO2N—, Rf is a straight or branched fluoroalkyl moiety having from 1 to 6 carbon atoms, and can, optionally, contain one or more in-chain heteroatoms, wherein Rf? is a straight or branched chain or cyclic fluoroalkylene having from 1 to 10 carbon atoms and can, optionally, contain one or more in-chain heteroatoms, and wherein both Rf and Rf? have a maximum of 20% non-fluorine substituents. The provided additives can improve the performance, hydrolytic stability, and thermal stability of the provided electrochemical cells.