Embodiments described herein relate to electrodes containing yolk-sell electroactive materials. In some aspects, an anode can include a carbon shell having an outer surface and an inner volume, the carbon shell including a plurality of pinholes on the outer surface. The anode particle is disposed in the inner volume of the carbon shell, such that a portion of the inner volume includes a void space. The anode further includes a plurality of graphene flakes disposed on the outer surface of the carbon shell, the plurality of graphene flakes covering at least a portion of the pinholes. In some embodiments, at least about 50% of the inner volume of the carbon shell can include void space. In some embodiments, the plurality of graphene flakes can cover at least about 90% of the pinholes.

Provided are reduced acylated graphene oxide as an electrode active material and a method for preparing the same. By the method for preparing reduced acylated graphene oxide according to the present invention, a negative electrode active material for a lithium secondary battery having stable activity and a high battery capacity may be prepared with a simple and low-cost process. In addition, the active material prepared by the preparation method has low resistance, a high battery capacity, and improved rate-limiting characteristics while having stable cycle characteristics.

A current collector, an electrochemical device containing the current collector, and an electronic device. The current collector includes a polymer substrate material and a conductive material. An electron resistivity of the current collector in an X-Y in-plane direction is 10 Ω.Math.cm to 1000 Ω.Math.cm, and an electron resistivity of the current collector in a Z direction is 0.01 Ω.Math.cm to 30 Ω.Math.cm. The current collector according to this application is excellent in oxidation resistance, reduction resistance, ionic insulation, mechanical strength, thermal stability, increases the energy density of bipolar electrochemical devices, and is more cost-effective and more suitable for mass production.

A lithium metal electrode is manufactured according to a process that bonds a layer of lithium metal to a conductive substrate on one side and to an ion selective membrane on another side. The lithium metal electrode may be integrated into lithium metal batteries. The inventive lithium metal electrode may be manufactured by a process involving electrolysis of lithium ions from an aqueous lithium salt solution through an ion selective membrane, carried out under a blanketing atmosphere having no more than 10 ppm of non-metallic elements, the electrolysis being performed at a constant current between about 10 mA/cm.sup.2 and about 50 mA/cm.sup.2, and wherein the constant current is applied for a time between about 1 minute and about 60 minutes.

One aspect of the present invention is a positive electrode for an energy storage device including a positive active material layer, in which the positive active material layer includes a positive active material particle having a ratio of a secondary particle size to a primary particle size of 3 or less, and a fibrous conductive agent.

The present relates to a positive electrode (1) for a non-aqueous electrolyte secondary battery, comprising: a positive electrode current collector (11) comprising a positive electrode current collector main both (14) formed of a metal material; a positive electrode active material layer (12) provided on the positive electrode current collector (11), wherein the positive electrode active material layer (12) comprises a positive electrode active material having, on at least a part of its surface, a coated section comprising a conductive material, the positive electrode active material layer (12) has a pore specific surface area of 5.0 to 10.0 m.sup.2/g and a central pore diameter of 0.06 to 0.15 μm, and a positive electrode (1) for a non-aqueous electrolyte secondary battery, comprising a positive electrode current collector (11) and a positive electrode active material layer (12) provided on the positive electrode current collector (11), wherein a thickness of the positive electrode active material layer (12) is 10 μm or more, the positive electrode active material layer (12) comprises a positive electrode active material, and a reflectance of a surface of the positive electrode active material layer (12) is 5.5% or higher in a wavelength range of 200 nm to 850 nm, and is not higher than a reflectance in the wavelength range of 200 nm to 850 nm peculiar to the positive electrode active material contained in the positive electrode active material layer (12).

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.

Methods and systems are provided for manufacturing a bipolar plate for a redox flow battery. In one example, the bipolar plate is fabricated by a roll-to-roll process. The bipolar plate includes a non-conductive substrate that is coupled to a negative electrode on a first surface and coupled to a positive electrode on a second surface, the first surface opposite of the second surface.

An alkali-ion battery is provided that includes an anhydrous alkaline salt as an active cathode material, where the alkaline salt may be, for example, a lithium sulfate salt, sodium sulfate salt or potassium sulfate salt, as the active cathode material. In some such batteries, the inter-conversion of sulfate to persulfate occurs during charging and discharging of the battery, respectively.

A battery pack having a population of secondary battery cells chargeable between a charged state and a discharged state, and a frame to hold secondary battery cells in the battery pack is provided, members of the population of secondary battery cells having an electrode assembly comprising a substantially polyhedral shape, and where the frame holds a cell array comprising a subset of the population of secondary batteries that are arranged adjacent to one another. A sealed secondary battery cell, electrode assembly, and methods of charging are also described.