An electrode current collector including a metal foil wherein a coating layer is formed on one or both surfaces of the metal foil, and a contact angle with pure water of the surface of the coating layer at a side opposite to the metal foil side is 30° or more.

A electric storage device that includes a device body having a first end face that has a first portion and a second portion, and second end face that has a third portion and a fourth portion. The second portion is inclined relative to the first portion, and the fourth portion is inclined relative to the third portion. A first electrode film extends from the first portion to the second portion, and a second electrode film extends from the third portion to the fourth portion.

To provide a power storage device whose charge and discharge characteristics are unlikely to be degraded by heat treatment. To provide a power storage device that is highly safe against heat treatment. The power storage device includes a positive electrode, a negative electrode, a separator, an electrolytic solution, and an exterior body. The separator is located between the positive electrode and the negative electrode. The separator contains polyphenylene sulfide or solvent-spun regenerated cellulosic fiber. The electrolytic solution contains a solute and two or more kinds of solvents. The solute contains LiBETA. One of the solvents is propylene carbonate.

To provide a power storage device whose charge and discharge characteristics are unlikely to be degraded by heat treatment. To provide a power storage device that is highly safe against heat treatment. The power storage device includes a positive electrode, a negative electrode, a separator, an electrolytic solution, and an exterior body. The separator is located between the positive electrode and the negative electrode. The separator contains polyphenylene sulfide or solvent-spun regenerated cellulosic fiber. The electrolytic solution contains a solute and two or more kinds of solvents. The solute contains LiBETA. One of the solvents is propylene carbonate.

Energy storage devices are disclosed that store both electrical and mechanical energies, making the total energy stored larger than either an electrical or mechanical means alone. The energy storage device is charged by the application of a voltage, which charges a capacitor to store electrical energy while simultaneously exerting a force on the mechanical system that deforms the mechanical system, resulting in mechanical energy storage. When the charged device is discharged, both the electrical and mechanical energy are extracted in electrical form. Its unique features include, but are not limited to, the potential for long lifetime, improved safety, better portability, a wide operating temperature range, and environment friendliness. Arrays of energy storage devices can be assembled in various configurations to build high capacity energy storage units.

Energy storage devices are disclosed that store both electrical and mechanical energies, making the total energy stored larger than either an electrical or mechanical means alone. The energy storage device is charged by the application of a voltage, which charges a capacitor to store electrical energy while simultaneously exerting a force on the mechanical system that deforms the mechanical system, resulting in mechanical energy storage. When the charged device is discharged, both the electrical and mechanical energy are extracted in electrical form. Its unique features include, but are not limited to, the potential for long lifetime, improved safety, better portability, a wide operating temperature range, and environment friendliness. Arrays of energy storage devices can be assembled in various configurations to build high capacity energy storage units.

An electrical storage device includes a case having first and second opposed main walls which face one another and at least one side wall coupled the first and second main walls. The case having a generally rectangular shape with outer corners and includes a cutout part having inner corners. An integrated electrode body is located in the case and is joined to the first main wall. The integrated body includes a first electrode, a second electrode, and a separator disposed between the first and second electrodes. The electrode body has a bending strength which is higher than a bending strength of the first main wall. An electrolyte fills the case.

An electrical storage device includes a case having first and second opposed main walls which face one another and at least one side wall coupled the first and second main walls. The case having a generally rectangular shape with outer corners and includes a cutout part having inner corners. An integrated electrode body is located in the case and is joined to the first main wall. The integrated body includes a first electrode, a second electrode, and a separator disposed between the first and second electrodes. The electrode body has a bending strength which is higher than a bending strength of the first main wall. An electrolyte fills the case.

An integrated energy storage device is provided that includes a supercapacitor and a battery surrounding the supercapacitor. The battery forms a shell around an exterior surface of the supercapacitor. The battery includes a first anode, a first cathode, and an electrolyte disposed between the first anode and the first cathode. The supercapacitor includes a second anode, a second cathode, and a separator disposed between the second anode and the second cathode.

An energy bank is provided that includes a plurality of integrated energy storage devices comprising a plurality of supercapacitors, a plurality of batteries and a plurality of metal shells. Each of the integrated energy storage devices comprises a supercapacitor, a battery surrounding the supercapacitor and a metal shell surrounding the battery. The battery forms a shell around an exterior surface of the supercapacitor. The battery includes a first anode, a first cathode, and an electrolyte disposed between the first anode and the first cathode. The supercapacitor includes a second anode, a second cathode, and a separator disposed between the second anode and the second cathode.