Abstract: High performance flow batteries, based on alkaline zinc/ferro-ferricyanide rechargeable (“ZnFe”) and similar flow batteries, may include one or more of the following improvements. First, the battery design has a cell stack comprising a low resistance positive electrode in at least one positive half cell and a low resistance negative electrode in at least one negative half cell, where the positive electrode and negative electrode resistances are selected for uniform high current density across a region of the cell stack. Second, a flow of electrolyte, such as zinc species in the ZnFe battery, with a high level of mixing through at least one negative half cell in a Zn deposition region proximate a deposition surface where the electrolyte close to the deposition surface has sufficiently high zinc concentration for deposition rates on the deposition surface that sustain the uniform high current density.

Abstract: High performance flow batteries, based on alkaline zinc/ferro-ferricyanide rechargeable (“ZnFe”) and similar flow batteries, may include one or more of the following improvements. First, the battery design has a cell stack comprising a low resistance positive electrode in at least one positive half cell and a low resistance negative electrode in at least one negative half cell, where the positive electrode and negative electrode resistances are selected for uniform high current density across a region of the cell stack. Second, a flow of electrolyte, such as zinc species in the ZnFe battery, with a high level of mixing through at least one negative half cell in a Zn deposition region proximate a deposition surface where the electrolyte close to the deposition surface has sufficiently high zinc concentration for deposition rates on the deposition surface that sustain the uniform high current density.

Abstract: Implementations of the present invention relate generally to high-capacity energy storage devices and methods and apparatus for fabricating high-capacity energy storage devices. In one implementation, a method for forming a multi-layer cathode structure is provided. The method comprises providing a conductive substrate, depositing a first slurry mixture comprising a cathodically active material to form a first cathode material layer over the conductive substrate, depositing a second slurry mixture comprising a cathodically active material to form a second cathode material layer over the first cathode material layer, and compressing the as-deposited first cathode material layer and the second cathode material layer to achieve a desired porosity.

Abstract: High performance flow batteries, based on alkaline zinc/ferro-ferricyanide rechargeable (“ZnFe”) and similar flow batteries, may include one or more of the following improvements. First, the battery design has a cell stack comprising a low resistance positive electrode in at least one positive half cell and a low resistance negative electrode in at least one negative half cell, where the positive electrode and negative electrode resistances are selected for uniform high current density across a region of the cell stack. Second, a flow of electrolyte, such as zinc species in the ZnFe battery, with a high level of mixing through at least one negative half cell in a Zn deposition region proximate a deposition surface where the electrolyte close to the deposition surface has sufficiently high zinc concentration for deposition rates on the deposition surface that sustain the uniform high current density.

Abstract: High performance flow batteries, based on alkaline zinc/ferro-ferricyanide rechargeable (“ZnFe”) and similar flow batteries, may include one or more of the following improvements. First, the battery design has a cell stack comprising a low resistance positive electrode in at least one positive half cell and a low resistance negative electrode in at least one negative half cell, where the positive electrode and negative electrode resistances are selected for uniform high current density across a region of the cell stack. Second, a flow of electrolyte, such as zinc species in the ZnFe battery, with a high level of mixing through at least one negative half cell in a Zn deposition region proximate a deposition surface where the electrolyte close to the deposition surface has sufficiently high zinc concentration for deposition rates on the deposition surface that sustain the uniform high current density.

Abstract: Embodiments described herein provide methods and systems for manufacturing faster charging, higher capacity energy storage devices that are smaller, lighter, and can be more cost effectively manufactured at a higher production rate. In one embodiment, a graded cathode structure is provided. The graded cathode structure comprises a conductive substrate, a first porous layer comprising a first cathodically active material having a first porosity formed on the conductive substrate, and a second porous layer comprising a second cathodically active material having a second porosity formed on the first porous layer. In certain embodiments, the first porosity is greater than the second porosity. In certain embodiments, the first porosity is less than the second porosity.