Methods and systems are provided for a redox flow battery system. In one example, a method of operating a redox flow battery system includes switching the redox flow battery system to an idle mode and completely draining electrolytes from one or more electrode compartments of the redox flow battery system. The one or more electrode compartments may be purged with a gas and refilled with fresh electrolytes.

The present invention relates to a flow battery system. The system comprises a first and second electrode comprising a lattice structure and at least one electrolyte supply configured to provide flow electrolyte through at least one of the first and second electrodes. A power circuit is operatively connected to the first and second electrodes to provide electrical power from the system.

An electrode comprising galvanic membranes having a thickness defined by an average length of vectors normal to a membrane first surface and extending to where said vectors intersect a membrane uncompressed second surface; a non-porous metal sheet having first and second surfaces; a non-porous dielectric sheet having first and second surfaces; square weave metal wire screens having a wire diameter slightly greater than one half the at least one galvanic membrane thickness dimension; wherein, at least one galvanic membrane is adjacent the metal wire screen on the at least one galvanic membrane first and second surfaces in a stack of membranes and screens; the metal wire screen is adjacent the first surface of the non-porous dielectric sheet; the second surfaces of non-porous metal sheets have a sustained pressure of at least 7 million Pascal; and; the metal wire screen is collectively in incompressible vertical alignment with another metal wire screen.

A redox flow battery system includes an anolyte having a first ionic species in solution; a catholyte having a second ionic species in solution, where the redox flow battery system is configured to reduce the first ionic species in the anolyte and oxidize the second ionic species in the catholyte during charging; a first electrode in contact with the anolyte, where the first electrode includes channels for collection of particles of reduced metallic impurities in the anolyte; a second electrode in contact with the catholyte; and a separator separating the anolyte from the catholyte. A method of reducing metallic impurities in an anolyte of a redox flow battery system includes reducing the metallic impurities in the anolyte; collecting particles of the reduced metallic impurities; and removing the collected particles using a cleaning solution.

A redox flow battery system includes an anolyte having a first ionic species in solution; a catholyte having a second ionic species in solution, where the redox flow battery system is configured to reduce the first ionic species in the anolyte and oxidize the second ionic species in the catholyte during charging; a first electrode in contact with the anolyte, where the first electrode includes channels for collection of particles of reduced metallic impurities in the anolyte; a second electrode in contact with the catholyte; and a separator separating the anolyte from the catholyte. A method of reducing metallic impurities in an anolyte of a redox flow battery system includes reducing the metallic impurities in the anolyte; collecting particles of the reduced metallic impurities; and removing the collected particles using a cleaning solution.

An electrode for electrochemical cells including an electrically conductive cohesive membrane having a thickness defined by a first surface and a second surface opposite the first surface; ohmic impedance independent of membrane thickness; simultaneous uniform charge/discharge throughout membrane thickness; the membrane comprising open cell pores and surfaces; a current collector electrically strongly coupled to the entire membrane thickness; and pins extending through the membrane from the first surface to the second surface; the pins electrically coupled to the current collector having eliminated prior art problematical interfacial layers.

Particular embodiments described herein provide for an electrode for a battery. The electrode including a current collector frame and an electrode substrate coupled to the current collector frame. An electrically conductive adhesive layer can be between the current collector frame and the electrode substrate and the electrically conductive adhesive layer can include a polymer binder and a conductive filler. The electrode substrate includes a porous material and active electrode material within the porous material. The porous material is copper foam, nickel foam, stainless steel foam, titanium foam, carbon felt, carbon cloth, or a carbon paper conductive polymer. The active electrode material includes one or more of manganese oxide, nickel oxide, vanadium oxide, titanium oxide, iron oxide, zinc metal, lead oxide, or lead.

A molten metal battery system includes a plurality of secondary cells electrically connected in series with each other and comprising a plurality of molten metal anodes arranged fluidly in parallel with each other. The system also includes a plurality of electrically isolated molten metal reservoirs, each of the molten metal reservoirs fluidly connected to a corresponding secondary cell of the plurality of secondary cells and configured to exchange molten metal with the corresponding secondary cell while preventing electrical shunt current from flowing between the plurality of secondary cells via the molten metal.

A method of determining a distribution of electrolytes in a flow battery includes providing a flow battery with a fixed amount of fluid electrolyte having a common electrochemically active specie, a portion of the fluid electrolyte serving as an anolyte and a remainder of the fluid electrolyte serving as a catholyte. An average oxidation state of the common electrochemically active specie is determined in the anolyte and the catholyte and, responsive to the determined average oxidation state, a molar ratio of the common electrochemically active specie between the anolyte and the catholyte is adjusted to increase an energy discharge capacity of the flow battery for the determined average oxidation state.

A method of determining a distribution of electrolytes in a flow battery includes providing a flow battery with a fixed amount of fluid electrolyte having a common electrochemically active specie, a portion of the fluid electrolyte serving as an anolyte and a remainder of the fluid electrolyte serving as a catholyte. An average oxidation state of the common electrochemically active specie is determined in the anolyte and the catholyte and, responsive to the determined average oxidation state, a molar ratio of the common electrochemically active specie between the anolyte and the catholyte is adjusted to increase an energy discharge capacity of the flow battery for the determined average oxidation state.