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 macroparticle filter device for cathodic arc evaporation, to be placed between at least one arc evaporation source and at least one substrate exhibiting at least a surface to be coated with material evaporated from a cathode of the arc evaporation source in a vacuum coating chamber. The macroparticle filter device includes one or more filter components that can prevent macroparticles emitted by the cathode during cathodic arc evaporation to arrive the substrate surface to be coated. The at least one component is provided as one or more flexible sheets that block the lineal way of the macroparticles from the cathode to the substrate surface to be coated. Further a method for utilizing the macroparticle filter device is presented.

A macroparticle filter device for cathodic arc evaporation, to be placed between at least one arc evaporation source and at least one substrate exhibiting at least a surface to be coated with material evaporated from a cathode of the arc evaporation source in a vacuum coating chamber. The macroparticle filter device includes one or more filter components that can prevent macroparticles emitted by the cathode during cathodic arc evaporation to arrive the substrate surface to be coated. The at least one component is provided as one or more flexible sheets that block the lineal way of the macroparticles from the cathode to the substrate surface to be coated. Further a method for utilizing the macroparticle filter device is presented.

A rechargeable lithium battery including an electrode assembly includes a positive electrode including a positive current collector and a positive active material layer disposed on the positive current collector; a negative electrode including a negative current collector, a negative active material layer disposed on the negative current collector, and a negative electrode functional layer disposed on the negative active material layer; and a separator, wherein the positive active material layer includes a first positive active material including at least one of a composite oxide of metal selected from cobalt, manganese, nickel, and a combination thereof and lithium and a second positive active material including a compound represented by Chemical Formula 1, the negative electrode functional layer includes flake-shaped polyethylene particles, and a battery capacity is greater than or equal to about 3.5 Ah.
Li.sub.aFe.sub.1−x1M.sub.x1PO.sub.4  [Chemical Formula 1] In Chemical Formula 1, 0.90≤a≤1.8, 0≤x1≤0.7, and M is Mn, Co, Ni, or a combination thereof.

Provided are a method for designing an electrode for a lithium secondary battery comprising measuring the electrical conductivity of an electrode with an alternating current to determine whether an electrical path in the electrode has been appropriately formed, and a method for manufacturing an electrode for a lithium secondary battery comprising the same. According to the present invention, it is possible to determine the content of a conductive agent in the electrode using the same.

A metal-ion battery cell is provided that comprises anode and cathode electrodes, a separator, and an electrolyte. The anode electrode may, for example, have a capacity loading in the range of about 2 mAh/cm2 to about 10 mAh/cm2 and comprise anode particles that (i) have an average particle size in the range of about 0.2 microns to about 40 microns, (ii) exhibit a volume expansion in the range of about 8 vol. % to about 180 vol. % during one or more charge-discharge cycles of the battery cell, and (iii) exhibit a specific capacity in the range of about 600 mAh/g to about 2600 mAh/g. The electrolyte may comprise, for example, (i) one or more metal-ion salts and (ii) a solvent composition that comprises one or more low-melting point solvents that each have a melting point below about −70° C. and a boiling point above about +70° C.

Low-cost electrochemical energy storage devices having electrochemical cells containing zinc electrodes in aqueous electrolytes, which exhibit superior cycle performance, preferably comprise the following elements: (a) a cathode formed of manganese dioxide particles, preferably doped with at least one of magnesium, strontium, barium, calcium, and lanthanum, wherein the manganese dioxide particles preferably form at least one of (1) a delta manganese dioxide structure and (2) a todokorite manganese dioxide structure; (b) an anode formed of particles comprising zinc, wherein the particles are preferably treated with at least one of bismuth, indium, gallium, antimony, and tin; (c) a mixed ion electrolyte solution with a pH greater than or equal to three and less than or equal to seven, wherein the solution preferably comprises at least one monovalent salt and at least one divalent salt; and (d) a mesh as cathode current collector comprising at least one of titanium, stainless steel, tantalum, and niobium, wherein the mesh is preferably coated by an electrically conductive and yet oxidation resistant material comprising but not limited to carbon.

Electrodes and methods of forming electrodes are described herein. The electrode can be an electrode of an electrochemical cell or battery. The electrode includes a current collector and a film in electrical communication with the current collector. The film may include a carbon phase that holds the film together. The electrode further includes an electrode attachment substance that adheres the film to the current collector.

The present application discloses a composite graphite material, a secondary battery, an apparatus and a preparation method thereof. The composite graphite material includes a core material and a coating layer coating at least a part of the surface of the core material, the core material including graphite; wherein the absolute value K of zeta potential of the composite graphite material in deionized water with a pH of 7 is at least 20 mV. The use of the composite graphite material provided by the present application can improve the cohesion and bonding force of the negative electrode plate, thereby reducing the cyclic expansion of the secondary battery.