Electrolyte composition and metal-ion battery employing the same

An electrolyte composition, comprising:

• a metal halide;
• an organic compound, wherein the organic compound is nitrogen-containing compound, a sulfur-containing compound, or a combination thereof;
• and
• a halogen-containing salt, wherein the halogen-containing salt has a structure represented by Formula (I)
• [Ca+]i[X−]j Formula (I),
• wherein C is IA element, IIA element, IIIA element, IVA element, VA element, VIA element, transition metal, pyrrolium, pyrrolinium, pyrrolidinium, pyridinium, ammonium, imidazolium, indazolium, pyrimidinium, azaannulenium, azathiazolium, benzimidazolium, benzofuranium, benzotriazolium, borolium, cholinium, cinnolinium, diazabicyclodecenium, diazabicyclononenium, diazabicyclo-undecenium, dithiazolium, furanium, guanidinium, indolinium, indolium, morpholinium, oxaborolium, oxaphospholium, oxazinium, oxazolium, iso-oxazolium, oxathiazolium, pentazolium, phospholium, phosphonium, phthalazinium, piperazinium, piperidinium, pyranium, pyrazinium, pyrazolium, pyridazinium, quinazolinium, quinolinium, iso-quinolinium, quinoxalinium, selenozolium, sulfonium, tetrazolium, iso-thiadiazolium, thiazinium, thiazolium, thiophenium, thiuronium, triazadecenium, triazinium, triazolium, iso-triazolium, or uronium;
• X is fluorine, chlorine, bromine, or iodine;
• a=j/i, i is 1, 2, 3, or 4, and j is 1, 2, 3, 4, 5, or 6, and wherein the molar ratio of the metal halide to the organic compound is greater than 2, and the molar ratio of the metal halide to the halogen-containing salt is greater than 2;
• and wherein the metal halide is distinct from the halogen-containing salt.