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.

The present invention relates to a method for preparing an electrode comprising a metal substrate, vertically aligned carbon nanotubes and a metal oxide deposited over the entire length of said vertically aligned carbon nanotubes, said method comprising the following consecutive steps: (a) synthesizing, on a metal substrate, a mat of vertically aligned carbon nanotubes; (b) electrochemically depositing the metal oxide on said carbon nanotubes from an electrolytic solution comprising at least one precursor of said metal oxide and at least one nitrate, said electrochemical deposition being carried out by a chronopotentiometry technique. The present invention also relates to the electrode thus prepared and to the uses thereof.

The present invention relates to a method for preparing an electrode comprising a metal substrate, vertically aligned carbon nanotubes and a metal oxide deposited over the entire length of said vertically aligned carbon nanotubes, said method comprising the following consecutive steps: (a) synthesizing, on a metal substrate, a mat of vertically aligned carbon nanotubes; (b) electrochemically depositing the metal oxide on said carbon nanotubes from an electrolytic solution comprising at least one precursor of said metal oxide and at least one nitrate, said electrochemical deposition being carried out by a chronopotentiometry technique. The present invention also relates to the electrode thus prepared and to the uses thereof.

Provided are a nonaqueous electrolyte capable of providing a nonaqueous electrolyte energy storage device with reduced direct current resistance and an increased capacity retention ratio after charge-discharge cycles, a nonaqueous electrolyte energy storage device including such a nonaqueous electrolyte, and a method for producing such a nonaqueous electrolyte energy storage device. One mode of the present invention is a nonaqueous electrolyte for an energy storage device, containing an additive represented by the following Formula (1) or Formula (2). In Formula (1), R.sup.1 to R.sup.4 are each independently a hydrogen atom or a group represented by —NR.sup.a.sub.2, —OR.sup.a, —SR.sup.a, etc., with the proviso that at least one of R.sup.1 to R.sup.4 is a group represented by —OR.sup.a, —SR.sup.a, —COOR.sup.a, —COR.sup.a, —SO.sub.2R.sup.a, or —SO.sub.3R.sup.a. In Formula (2), R.sup.5 to R.sup.7 are each independently a hydrogen atom or a group represented by —NR.sup.b.sub.2, —OR.sup.b, or —SR.sup.b, with the proviso that at least one of R.sup.5 to R.sup.7 is a group represented by —SR.sup.b. ##STR00001##

Provided are a nonaqueous electrolyte capable of providing a nonaqueous electrolyte energy storage device with reduced direct current resistance and an increased capacity retention ratio after charge-discharge cycles, a nonaqueous electrolyte energy storage device including such a nonaqueous electrolyte, and a method for producing such a nonaqueous electrolyte energy storage device. One mode of the present invention is a nonaqueous electrolyte for an energy storage device, containing an additive represented by the following Formula (1) or Formula (2). In Formula (1), R.sup.1 to R.sup.4 are each independently a hydrogen atom or a group represented by —NR.sup.a.sub.2, —OR.sup.a, —SR.sup.a, etc., with the proviso that at least one of R.sup.1 to R.sup.4 is a group represented by —OR.sup.a, —SR.sup.a, —COOR.sup.a, —COR.sup.a, —SO.sub.2R.sup.a, or —SO.sub.3R.sup.a. In Formula (2), R.sup.5 to R.sup.7 are each independently a hydrogen atom or a group represented by —NR.sup.b.sub.2, —OR.sup.b, or —SR.sup.b, with the proviso that at least one of R.sup.5 to R.sup.7 is a group represented by —SR.sup.b. ##STR00001##

The invention provides electrolyte compositions including a metal cation, an ionic liquid, and a chelator that coordinates the metal cation. The electrolyte compositions are advantageous as they exhibit increased ion transference, and thus increased total conductivity, relative to a pure ionic liquid electrolyte that coordinates the metal cation. The invention provides a general strategy to control the cation-anion dynamics that govern ionic liquid performance. Electrolytes of the invention may be useful for any suitable purpose, e.g., in primary and secondary batteries, supercapacitors, and solar cells.

The invention provides electrolyte compositions including a metal cation, an ionic liquid, and a chelator that coordinates the metal cation. The electrolyte compositions are advantageous as they exhibit increased ion transference, and thus increased total conductivity, relative to a pure ionic liquid electrolyte that coordinates the metal cation. The invention provides a general strategy to control the cation-anion dynamics that govern ionic liquid performance. Electrolytes of the invention may be useful for any suitable purpose, e.g., in primary and secondary batteries, supercapacitors, and solar cells.

An aspect of the present invention is a nonaqueous electrolyte energy storage device that includes a negative electrode including a lithium alloy and a nonaqueous electrolyte containing a fluorinated solvent, in which the lithium alloy contains silver, and the content of silver with respect to the total content of lithium and silver in the lithium alloy is 3% by mass or more and 20% by mass or less. Another aspect of the present invention is a nonaqueous electrolyte energy storage device that includes a negative electrode including a lithium alloy and a nonaqueous electrolyte including a lithium salt containing fluorine, in which the lithium alloy contains silver, and the content of silver with respect to the total content of lithium and silver in the lithium alloy is 3% by mass or more and 20% by mass or less.

An electrochemical device includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and an electrolytic solution. The positive electrode active material contains a conductive polymer, and the electrolytic solution contains anions with which the conductive polymer is doped and dedoped. In the discharged state, the concentration of the anions in the electrolytic solution is in the range from 1.1 mol/L to 1.6 mol/L, inclusive.