An electrolyte for a lithium-ion battery includes a primary lithium salt and an organic compound composition. In some designs, the organic compound composition includes (1) fluoroethylene carbonate (FEC), (2) vinylene carbonate (VC), (3) at least one ester (ES), and (4) a nitrile additive composition (NAC) which includes at least one nitrile compound. In some designs, a mole fraction of the NAC in the electrolyte is in a range of approximately 0.1 mol. % to approximately 2.0 mol. %. In some designs, a mole fraction of the at least one ES in the electrolyte is at least approximately 35 mol. %.

An electrolyte for a lithium-ion battery includes a primary lithium salt and an organic compound composition. In some designs, the organic compound composition includes (1) fluoroethylene carbonate (FEC), (2) vinylene carbonate (VC), (3) at least one ester (ES), and (4) a nitrile additive composition (NAC) which includes at least one nitrile compound. In some designs, a mole fraction of the NAC in the electrolyte is in a range of approximately 0.1 mol. % to approximately 2.0 mol. %. In some designs, a mole fraction of the at least one ES in the electrolyte is at least approximately 35 mol. %.

An electrochemical cell including an additive mixture for alleviating the symptoms of overcharge is disclosed. The additive mixture may include a combination of at least two of diethyl allylphosphonate, 4-fluorobiphenyl, and 1-phenyl-1-cyclohexene. For example, an electrolyte may include allylphosphonate and 4-fluorobiphenyl. In yet another example, an electrolyte may include 1-phenyl-1-cyclohexene.

An electrochemical cell including an additive mixture for alleviating the symptoms of overcharge is disclosed. The additive mixture may include a combination of at least two of diethyl allylphosphonate, 4-fluorobiphenyl, and 1-phenyl-1-cyclohexene. For example, an electrolyte may include allylphosphonate and 4-fluorobiphenyl. In yet another example, an electrolyte may include 1-phenyl-1-cyclohexene.

An electrolyte solution additive, an electrolyte solution including the same, and a lithium secondary battery including the same are disclosed herein. In some embodiments, an electrolyte solution additive includes a compound represented by Formula 1:

##STR00001##

Wherein X is oxygen (O) or sulfur (S), and R is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms or N(R.sub.1).sub.2, wherein R.sub.1 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms. The additive has an excellent effect of scavenging a decomposition product generated from a lithium salt and simultaneously forming a robust film on a surface of a positive electrode.

An electrolyte solution additive, an electrolyte solution including the same, and a lithium secondary battery including the same are disclosed herein. In some embodiments, an electrolyte solution additive includes a compound represented by Formula 1:

##STR00001##

Wherein X is oxygen (O) or sulfur (S), and R is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms or N(R.sub.1).sub.2, wherein R.sub.1 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms. The additive has an excellent effect of scavenging a decomposition product generated from a lithium salt and simultaneously forming a robust film on a surface of a positive electrode.

Articles and methods including additives in electrochemical cells, are generally provided. As described herein, such electrochemical cells may comprise an anode, a cathode, an electrolyte, and optionally a separator. In some embodiments, at least one of the anode, the cathode, the electrolyte, and/or the optional separator may comprise an additive and/or additive precursor. For instance, in some cases, the electrochemical cell comprises an electrolyte and an additive and/or additive precursor that is soluble with and/or is present in the electrolyte. In some embodiments, the additive precursor comprises a disulfide bond. In certain embodiments, the additive is a carbon disulfide salt. In some cases, the electrolyte may comprise a nitrate.

Articles and methods including additives in electrochemical cells, are generally provided. As described herein, such electrochemical cells may comprise an anode, a cathode, an electrolyte, and optionally a separator. In some embodiments, at least one of the anode, the cathode, the electrolyte, and/or the optional separator may comprise an additive and/or additive precursor. For instance, in some cases, the electrochemical cell comprises an electrolyte and an additive and/or additive precursor that is soluble with and/or is present in the electrolyte. In some embodiments, the additive precursor comprises a disulfide bond. In certain embodiments, the additive is a carbon disulfide salt. In some cases, the electrolyte may comprise a nitrate.

An electrolyte for use in an energy storage device, an energy storage device and a method of forming such electrolyte. The electrolyte includes a polymer matrix of at least two crosslinked structures, including a first polymeric material and a second polymeric material; and an electrolytic solution retained by the polymer matrix; wherein the electrolyte is arranged to physically deform when subjected to an external mechanical load applied to the polymer matrix.

An electrolyte for use in an energy storage device, an energy storage device and a method of forming such electrolyte. The electrolyte includes a polymer matrix of at least two crosslinked structures, including a first polymeric material and a second polymeric material; and an electrolytic solution retained by the polymer matrix; wherein the electrolyte is arranged to physically deform when subjected to an external mechanical load applied to the polymer matrix.