Disclosed herein is electrode comprising a current collector comprising a conductor layer having at least a first surface; and elongated metal carbide nanostructures extending from the first surface; and a carbonaceous energy storage media disposed on the first surface and in contact with the elongated metal carbide nanostructures. Disclosed herein too is an ultracapacitor comprising at least one electrode comprising a current collector comprising a conductor layer having at least a first surface; and elongated metal carbide nanostructures extending from the first surface; and a carbonaceous energy storage media disposed on the first surface and in contact with the elongated metal carbide nanostructures.

A flexible energy storage device with a redox-active polymer hydrogel electrolyte is provided. The flexible energy storage device can include a pair of electrodes separated by the redox-active polymer hydrogel electrolyte. The redox-active polymer hydrogel electrolyte can include a polymer hydrogel, charge balancing anions and redox-active transition metal cations at least one selected from the group consisting of vanadium, chromium, manganese, cobalt, and copper. The flexible energy storage device may retain greater than 75% of an unbent specific capacitance when bent at an angle of 10° to 170°.

A flexible energy storage device with a redox-active polymer hydrogel electrolyte is provided. The flexible energy storage device can include a pair of electrodes separated by the redox-active polymer hydrogel electrolyte. The redox-active polymer hydrogel electrolyte can include a polymer hydrogel, charge balancing anions and redox-active transition metal cations at least one selected from the group consisting of vanadium, chromium, manganese, cobalt, and copper. The flexible energy storage device may retain greater than 75% of an unbent specific capacitance when bent at an angle of 10° to 170°.

A scaffold includes struts that intersect at nodes. In some instances, a cross section of the cores has at least one dimension less than 100 microns. The core can be a solid, liquid or a gas. In some instances, one or more shell layers are positioned on the core.

A scaffold includes struts that intersect at nodes. In some instances, a cross section of the cores has at least one dimension less than 100 microns. The core can be a solid, liquid or a gas. In some instances, one or more shell layers are positioned on the core.

An electrolyte is introduced into an electrochemical device, passed, via a first corrugation feature, through a first electrode of the electrochemical device, passed through an ion permeable separator, and contacted with a second electrode. The first or second electrode comprises a second corrugation feature in fluid communication with the first corrugation feature to contact the electrolyte across a portion of an active surface of the first or second electrode.

An electrolyte is introduced into an electrochemical device, passed, via a first corrugation feature, through a first electrode of the electrochemical device, passed through an ion permeable separator, and contacted with a second electrode. The first or second electrode comprises a second corrugation feature in fluid communication with the first corrugation feature to contact the electrolyte across a portion of an active surface of the first or second electrode.

A flexible energy storage device with a glycerol-based gel electrolyte is provided. The flexible energy storage device can include a pair of electrodes separated by the gel electrolyte. The electrolytes can be in gel form, bendable and stretchable in a device. The gel electrolyte can include glycerol, redox-active molybdenum-containing ions, and a secondary ionic substance. The secondary ionic substance can include a salt. The gel electrolyte can have a density of 1.4 to 1.9 g/cm.sup.3 and an ionic conductivity of 2.3×10.sup.−4 to 3.2×10.sup.−4 Scm.sup.−1. The flexible energy storage device may retain greater than 95% of an unbent energy storage capacity when bent at an angle of 10 to 170°.

A flexible energy storage device with a glycerol-based gel electrolyte is provided. The flexible energy storage device can include a pair of electrodes separated by the gel electrolyte. The electrolytes can be in gel form, bendable and stretchable in a device. The gel electrolyte can include glycerol, redox-active molybdenum-containing ions, and a secondary ionic substance. The secondary ionic substance can include a salt. The gel electrolyte can have a density of 1.4 to 1.9 g/cm.sup.3 and an ionic conductivity of 2.3×10.sup.−4 to 3.2×10.sup.−4 Scm.sup.−1. The flexible energy storage device may retain greater than 95% of an unbent energy storage capacity when bent at an angle of 10 to 170°.

An interfacial protective coating layer of LTO is effective in preventing unwanted interfacial reactions between the solid-state electrolyte and cathode electrodes from occurring. Incorporation of the inventive coating into sodium-based all-solid-state batteries allows for room temperature operation, high voltage, and long cycle life.