Disclosed herein are ionic liquid electrolytes comprising lithium cations, sodium cations, organic cations, and fluorinated anions, wherein a concentration of the lithium cations is about 1.3 M or greater. Also disclosed are batteries comprising an anode, a cathode, and the electrolyte of this disclosure disposed between the anode and the cathode.

Disclosed herein are ionic liquid electrolytes comprising lithium cations, sodium cations, organic cations, and fluorinated anions, wherein a concentration of the lithium cations is about 1.3 M or greater. Also disclosed are batteries comprising an anode, a cathode, and the electrolyte of this disclosure disposed between the anode and the cathode.

There is provided a separator for an electricity storage device, comprising a polyolefin resin microporous membrane and an inorganic porous layer arranged on at least one surface of the polyolefin resin microporous membrane, wherein the inorganic porous layer has at least one selected from the group consisting of (i) covalent bonding between inorganic particles, (ii) covalent bonding between resin binders, and (iii) covalent bonding between an inorganic particle and a resin binder, and the polyolefin resin microporous membrane comprises a silane graft-modified polyolefin, and a silane crosslinking reaction in the silane graft-modified polyolefin is initiated when the separator for an electricity storage device is brought into contact with an electrolyte solution.

There are provided an aqueous electrolyte solution having an extended potential window, in particular, an aqueous electrolyte solution whose potential window is further wider than those exhibited by conventional concentrated aqueous electrolyte solutions, and an aqueous electrolyte solution in which the cycle characteristics can be improved. A non-aqueous electrolyte solution capable of achieving a higher energy density is provided, the non-aqueous electrolyte solution containing easily available and inexpensive materials and having further improved characteristics. One aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive. One other non-aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive.

There are provided an aqueous electrolyte solution having an extended potential window, in particular, an aqueous electrolyte solution whose potential window is further wider than those exhibited by conventional concentrated aqueous electrolyte solutions, and an aqueous electrolyte solution in which the cycle characteristics can be improved. A non-aqueous electrolyte solution capable of achieving a higher energy density is provided, the non-aqueous electrolyte solution containing easily available and inexpensive materials and having further improved characteristics. One aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive. One other non-aqueous electrolyte solution of the present embodiment contains a salt of at least one selected from the group consisting of sodium, magnesium, potassium and lithium, and a chaotropic additive.

A non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution, wherein the positive electrode includes a composite oxide including lithium as a first metal, and a second metal X other than lithium; in the composite oxide, the second metal X includes Ni, Al, and Mn; the second metal X does not contain Co or the atomic ratio Co/X of Co to the second metal X is 0.02 or less; and the electrolyte solution contains a chain carboxylic acid ester having 2 to 4 carbon atoms, and a cyclic compound having a ring structure composed of 2 oxygen atoms and 3 to 5 carbon atoms.

A non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution, wherein the positive electrode includes a composite oxide including lithium as a first metal, and a second metal X other than lithium; in the composite oxide, the second metal X includes Ni, Al, and Mn; the second metal X does not contain Co or the atomic ratio Co/X of Co to the second metal X is 0.02 or less; and the electrolyte solution contains a chain carboxylic acid ester having 2 to 4 carbon atoms, and a cyclic compound having a ring structure composed of 2 oxygen atoms and 3 to 5 carbon atoms.

A silicon-polymer composite anode having two or more different molecular weight (MW) versions of the same polymer, method of making the anode and electrochemical energy storage device containing the anode are disclosed.

A silicon-polymer composite anode having two or more different molecular weight (MW) versions of the same polymer, method of making the anode and electrochemical energy storage device containing the anode are disclosed.

The present invention provides a lithium ion battery and an electrolyte thereof. The electrolyte for the lithium ion battery includes a non-aqueous organic solvent, a lithium salt and additives, wherein the additives include additive A cyclophosphazene compound, additive B lithium fluorophosphate compound, and additive C selected from at least one of silane phosphate compound, silane phosphite compound and silane borate compound. Compared with conventional technologies, the nickel-rich positive electrode lithium ion battery using the electrolyte of the present invention has a desirable cyclic capacity retention rate, a desirable storage capacity retention rate and a low gas production at high temperature, and has a low DC internal resistance at low temperature, which can remarkably improve the thermal stability of lithium ion battery.