The present disclosure provides supercapacitors that may avoid the shortcomings of current energy storage technology. Provided herein are electrochemical systems, comprising three dimensional porous reduced graphene oxide film electrodes. Prototype supercapacitors disclosed herein may exhibit improved performance compared to commercial supercapacitors. Additionally, the present disclosure provides a simple, yet versatile technique for the fabrication of supercapacitors through the direct preparation of three dimensional porous reduced graphene oxide films by filtration and freeze casting.

Anodes made from powder, such as tantalum powder, that is highly spherical is described. Methods to make the anodes are further described.

In an illustrative embodiment, a supercapacitor system includes a common bus and a number of supercapacitor units, each of the supercapacitor units including one or more supercapacitors, coupled to the common bus via a balancing circuit, where each balancing circuit is configured to balance a charge of the one or more supercapacitors in the supercapacitor units by conducting current to supercapacitor units with a lower charge from supercapacitor units with a higher charge over the common bus, each balancing circuit including at least a first switch and a second switch, each switch controlled by a clock signal.

An electrochemical capacitor includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolytic solution. The electrolytic solution contains a lactone compound. A capacity of the positive electrode is greater than a capacity of the negative electrode and is less than or equal to 1.6 times of the capacity of the negative electrode.

The present invention relates to a porous carbon material having a co-continuous structure forming portion in which carbon skeletons and voids form continuous structures, respectively and which has a structural period of 0.002 m to 3 m, having pores which have an average diameter of 0.01 to 10 nm on a surface thereof, and having a BET specific surface area of 100 m.sup.2/g or more.

The present invention relates to a porous carbon material having a co-continuous structure forming portion in which carbon skeletons and voids form continuous structures, respectively and which has a structural period of 0.002 m to 3 m, having pores which have an average diameter of 0.01 to 10 nm on a surface thereof, and having a BET specific surface area of 100 m.sup.2/g or more.

Provided is an electrode material which has a co-continuous porous structure configured from a carbon skeleton and voids and which, by providing a large surface area, has excellent electrical conductivity, thermal conductivity, etc. This electrode material includes a porous carbon material having a co-continuous structure portion in which a carbon skeleton and voids form a continuous structure, and in the porous carbon material, the specific surface area measured by the BET method is 1 to 4500 m.sup.2/g, and the pore volume measured by the BJH method is 0.01 to 2.0 cm.sup.3/g.

The present application is generally directed to energy storage materials such as activated carbon comprising enhanced particle packing properties and devices containing the same. The energy storage materials find utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making the energy storage materials are also disclosed.

The present invention provides an electrode material for metal-air batteries which has a homogeneous co-continuous structure due to a carbon skeleton and voids and is excellent in terms of permeability to and diffusibility of ions, oxygen, electrolytes, and electrolytic solutions and which, due to the formation of the carbon network, can rapidly diffuse the heat generated by battery reactions and has satisfactory electrical conductivity. The electrode material for metal-air batteries includes a porous carbon material having a co-continuous structure portion in which a skeleton constituted of carbon and voids form a co-continuous structure and which has a structural period, as calculated by X-ray scattering method or X-ray CT method, of 0.002-10 m.

The present invention provides an electrode material for metal-air batteries which has a homogeneous co-continuous structure due to a carbon skeleton and voids and is excellent in terms of permeability to and diffusibility of ions, oxygen, electrolytes, and electrolytic solutions and which, due to the formation of the carbon network, can rapidly diffuse the heat generated by battery reactions and has satisfactory electrical conductivity. The electrode material for metal-air batteries includes a porous carbon material having a co-continuous structure portion in which a skeleton constituted of carbon and voids form a co-continuous structure and which has a structural period, as calculated by X-ray scattering method or X-ray CT method, of 0.002-10 m.