ESS Tech, Inc.

A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

Systems and methods are provided for recovering performance of rebalancing systems of a redox flow battery system. The method includes contacting a catalyst of the rebalancing system with a citrate solution. The citrate solution disperses a diffusion double layer from a surface of the catalyst.

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

Systems and methods are provided for a cell of a redox flow battery system. The electrode cell includes a membrane frame assembly, a bipolar plate frame assembly, and a thermal weld positioned between the membrane frame assembly and the bipolar plate frame assembly. The thermal weld includes material from a frame of the membrane frame assembly and a frame of the bipolar plate frame assembly.

Systems and methods are provided for managing an energy storage system. In one example, a method may include directing energy stored in the energy storage system to a cryptocurrency mining system and another consumer responsive to conditions. Other consumers may include a third party consumer of energy and conditions may include current and predicted cryptocurrency values and current and predicted availability of cyclically available renewable energy.

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery is adapted with an additive included in a battery electrolyte and an anion exchange membrane separator dividing positive electrolyte from negative electrolyte. An overall system cost of the battery system may be reduced while a storage capacity, energy density and performance may be increased.

A method for a redox flow battery system may include flowing an electrolyte from an electrolyte storage tank to a multi-stage rebalancing reactor, the multi-stage rebalancing reactor comprising reactor vessels grouped to form stages. Hydrogen gas may be injected into the electrolyte upstream of the multi-stage rebalancing reactor via a gas line and a metal ion of the electrolyte may be chemically reduced by oxidizing the hydrogen gas at a catalyst bed of each of the reactor vessels to maintain a charge balance of the electrolyte and a pH of the electrolyte within a predetermined range.

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery system includes a cell stack compressed between terminal structures defining ends of the redox flow battery. The cell stack may be formed of a plurality of cells where each cell includes a deformable positive electrode in contact with a first face of a membrane separator and a negative electrode configured to be less compressible than the positive electrode and arranged at a second face of the membrane separator.

Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery system has a first redox flow battery and a second redox flow battery, stacked above and in contact with the first redox flow battery along a vertical axis of the redox flow battery system. The second redox flow battery may be coupled to the first redox flow battery via nesting detents. Furthermore, operation of the first redox flow battery and the second redox flow battery may be adjustable according to a power demand.