FORM ENERGY, INC.

In an aspect, provide is an alkaline rechargeable battery comprising: i) a battery container sealed against the release of gas up to at least a threshold gas pressure, ii) a volume of an aqueous alkaline electrolyte at least partially filling the container to an electrolyte level; iii) a positive electrode containing positive active material and at least partially submerged in the electrolyte; iv) an iron negative electrode at least partially submerged in the electrolyte, the iron negative electrode comprising iron active material; v) a separator at least partially submerged in the electrolyte provided between the positive electrode and the negative electrode; vi) an auxiliary oxygen gas recombination electrode electrically connected to the iron negative electrode by a first electronic component, ionically connected to the electrolyte by a first ionic pathway, and exposed to a gas headspace above the electrolyte level by a first gas pathway.

According to one aspect, a system for electrochemical power storage may include a plurality of instances of a metal-air battery, each instance of the metal-air battery including an air electrode, a metal electrode, and a liquid electrolyte separating the air electrode from the metal electrode with the air electrode and the metal electrode ionically coupled to one another via the liquid electrolyte; and a carbon dioxide removal system into which ambient air is directable, carbon dioxide from the ambient air removable in the carbon dioxide removal system to generate purified air, and the carbon dioxide removal system in fluid communication with the plurality of instances of the metal-air batteries such that the purified air is movable from the carbon dioxide removal system to the plurality of instances of the metal-air battery.

Various embodiments provide a battery, a bulk energy storage system including the battery, and/or a method of operating the bulk energy storage system including the battery. In various embodiment, the battery may include a first electrode, an electrolyte, and a second electrode, wherein one or both of the first electrode and the second electrode comprises direct reduced iron (“DRI”). In various embodiments, the DRI may be in the form of pellets. In various embodiments, the pellets may comprise at least about 60 wt % iron by elemental mass, based on the total mass of the pellets. In various embodiments, one or both of the first electrode and the second electrode comprises from about 60% to about 90% iron and from about 1% to about 40% of a component comprising one or more of the materials selected from the group of SiO 2 , Al 2 O 3 , MgO, CaO, and TiO 2 .

Methods and systems of the present disclosure are generally directed to purification of metal-containing material. For example, soft oxidation may be used to generate an oxygen-free product from a low-quality alloy of a base metal. The oxygen-free product may be electrolyzed directly to generate a higher-quality alloy of the base metal—namely, an alloy with higher weight percentage of the base metal and, thus, lower weight percentage of tramp elements. As compared to recycling the base metal with a metal-air electrochemical cell, the methods and systems of the present disclosure may facilitate forming high-quality recycled metal (e.g., aluminum) using significantly less energy.

A stationary hybrid battery back-up system incorporates two different battery units that differ in terms of recharging efficiency, cycle life, power capability, depth of discharge threshold, temperature threshold, internal impedance threshold, charger rate efficiency and/or stand-by efficiency. The battery back-up system of the present invention comprises an auxiliary power supply that can be used to charge the first and second batteries and/or provide power to a load. When the operating voltage of the system drops, due to a power failure of a power source, the control system may couple the first and/or second battery unit to a load. The control system may have voltage threshold limits wherein it engages the first and second battery units to support the load demand. The first and second battery units may be charge by the auxiliary power supply when the operating voltage is above a threshold level.

Detailed herein are systems and methods for large volume design, building, and testing, particularly suited for rechargeable batteries intended for long duration energy storage. A specific item, such as a battery cell, may be designed through input and selection of various components and configurations, along with desired test protocols and configurations. A build team is notified of the new item, and confirms material and resources are ready to build the item. A specific channel is reserved or committed for the test. Test data, along with specifics and any errors or conditions encountered from specification through teardown, is tracked.

A methane-oxygen battery system including an electrochemical cell including a positive electrode, a negative electrode, and an electrolyte; a reactor in fluid communication with the negative electrode; a fuel gauge; and a gas store including a first compartment in fluid communication with the positive electrode and configured to store oxygen, a second compartment in fluid communication with the negative electrode and configured to store carbon dioxide and water, a third compartment in fluid communication with the negative electrode or the reactor and configured to store methane, a first barrier between the first compartment and the second compartment, and a second barrier between the second compartment and the third compartment. The gas store and the electrochemical cell form a closed system. The fuel gauge is configured to determine a state of charge based on a position of at least one of the first barrier or the second barrier.

A carbon-oxygen battery system, including a Boudouard reactor in fluid communication with an electrochemical cell; a carbon store configured to store carbon; a gas store in fluid communication with the electrochemical cell, and a fuel gauge. The gas store is configured to separately store oxygen and a carbon-containing gas, wherein the gas store comprises a movable barrier separating the oxygen from the carbon-containing gas. The fuel gauge configured to determine a state of charge based on a position of the movable barrier, a mass of the oxygen in the gas store, a mass of the carbon-containing gas in the gas store, a mass of carbon in the carbon store, a volume of carbon in the carbon store, or a combination thereof. The gas store and the electrochemical cell form a closed system.

A metal-oxygen battery system, including: an electrochemical cell including a positive electrode, a negative electrode, and an electrolyte between the positive electrode and the negative electrode; and an energy storage reactor in fluid communication with the negative electrode; a gas store in fluid communication with the positive electrode, the gas store configured to store oxygen; and a fuel gauge configured to determine a state of charge, wherein the gas store and the positive electrode form a closed system.

Oxygen evolution electrodes having high surface area plating and methods of forming such oxygen evolution electrodes are described. According to one aspect, an electrode for an oxygen evolution reaction (OER) may include a substrate including at least one surface and a layer of nickel coated on the at least one surface of the substrate. The at least one surface of the substrate has a first surface area, the layer of nickel has a second surface area, and a ratio of the second surface area to the first surface area is greater than about 10:1 and less than about 50:1.