A negative electrode active material containing a negative electrode active material particle which includes a silicon compound particle containing a silicon compound (SiO.sub.x: 0.5≤x≤1.6). The silicon compound particle has three or more peaks in a chemical shift value ranging from −40 ppm to −120 ppm but has no peak in a chemical shift value within a range of −65±3 ppm in a spectrum obtained from .sup.29Si-MAS-NMR of the silicon compound particle. This provides a negative electrode active material capable of improving cycle characteristics when it is used as a negative electrode active material for a secondary battery.

Systems and methods are provided for high volume roll-to-roll direct coating of electrodes for silicon-dominant anode cells and may include applying a slurry to a current collector film, the slurry comprising silicon particles and a binder material; drying the slurry to form a precursor composite film; rolling the current collector film into a precursor composite roll; and applying a heat treatment to the precursor composite film and the current collector film in a nitrogen gas environment, wherein the heat treatment is configured for converting the precursor composite film to a pyrolyzed composite film. The heat treatment may include one or both of: applying the heat treatment to a roll comprising the precursor composite roll in whole; and applying the heat treatment to the current collector film as it is continuously fed from the precursor composite roll.

Systems and methods are provided for high volume roll-to-roll direct coating of electrodes for silicon-dominant anode cells and may include applying a slurry to a current collector film, the slurry comprising silicon particles and a binder material; drying the slurry to form a precursor composite film; rolling the current collector film into a precursor composite roll; and applying a heat treatment to the precursor composite film and the current collector film in a nitrogen gas environment, wherein the heat treatment is configured for converting the precursor composite film to a pyrolyzed composite film. The heat treatment may include one or both of: applying the heat treatment to a roll comprising the precursor composite roll in whole; and applying the heat treatment to the current collector film as it is continuously fed from the precursor composite roll.

Electrically-conductive articles are provided that include a current collector having a conductive coating. The current collector has nanoporous structure, such as that from etched metal, and a carbon coating in contact with the current collector. The carbon coating is free of binder. In some embodiments, the current collector includes etched aluminum. The provided electrically-conductive articles can be electrochemical capacitors or lithium-ion electrochemical cells.

Electrically-conductive articles are provided that include a current collector having a conductive coating. The current collector has nanoporous structure, such as that from etched metal, and a carbon coating in contact with the current collector. The carbon coating is free of binder. In some embodiments, the current collector includes etched aluminum. The provided electrically-conductive articles can be electrochemical capacitors or lithium-ion electrochemical cells.

To improve the reliability of a power storage device. A granular active material including carbon is used, and a net-like structure is formed on part of a surface of the granular active material. In the net-like structure, a carbon atom included in the granular active material is bonded to a silicon atom or a metal atom through an oxygen atom. Formation of the net-like structure suppresses reductive decomposition of an electrolyte solution, leading to a reduction in irreversible capacity. A power storage device using the above active material has high cycle performance and high reliability.

To improve the reliability of a power storage device. A granular active material including carbon is used, and a net-like structure is formed on part of a surface of the granular active material. In the net-like structure, a carbon atom included in the granular active material is bonded to a silicon atom or a metal atom through an oxygen atom. Formation of the net-like structure suppresses reductive decomposition of an electrolyte solution, leading to a reduction in irreversible capacity. A power storage device using the above active material has high cycle performance and high reliability.

A battery and a method of constructing a battery are disclosed in which a first conductive substrate portion has a first face and a second conductive substrate portion has a second face opposed to the first face. A first electrode material is disposed in electrical contact with the first face, an electrolyte material is disposed in contact with the first electrode material, a second electrode material is disposed in contact with the electrolyte material, and a conductive tab disposed in contact with the second electrode material. The first conductive substrate portion, the first electrode material, and the conductive tab extend outward beyond a particular edge of the second conductive substrate portion.

A battery and a method of constructing a battery are disclosed in which a first conductive substrate portion has a first face and a second conductive substrate portion has a second face opposed to the first face. A first electrode material is disposed in electrical contact with the first face, an electrolyte material is disposed in contact with the first electrode material, a second electrode material is disposed in contact with the electrolyte material, and a conductive tab disposed in contact with the second electrode material. The first conductive substrate portion, the first electrode material, and the conductive tab extend outward beyond a particular edge of the second conductive substrate portion.

Various embodiments of the present disclosure describe energy storage devices. In one example, an energy storage device includes an anode having a plurality of active material particles, a cathode having a transition metal oxide material, and an electrolyte including a room temperature ionic liquid to couple the anode to the cathode. Each of the plurality of anode active material particles have a particle size of between about one micrometer and about fifty micrometers. One or more of the plurality of anode active material particles are enclosed by and in contact with a membrane coating permeable to lithium ions.