A positive electrode composition is presented. The composition includes granules that comprise an electroactive metal, an alkali metal halide, and a metal sulfide composition that is substantially-free of oxygen. A molar ratio of the electroactive metal to an amount of sulfur in the metal sulfide composition is between about 1.5:1 and about 50:1. The positive electrode composition is substantially free of iron oxide, iron sulfate, cobalt oxide and cobalt sulfate. An energy storage device and a related energy storage system are also described.

An electrochemical cell includes solid-state, printable anode layer, cathode layer and non-aqueous gel electrolyte layer coupled to the anode layer and cathode layer. The electrolyte layer provides physical separation between the anode layer and the cathode layer, and comprises a composition configured to provide ionic communication between the anode layer and cathode layer by facilitating transmission of multivalent ions between the anode layer and the cathode layer.

An exemplary electrochemical energy storage device includes: a positive electrode including a positive electrode active material; a negative electrode including a negative electrode active material; and a non-aqueous electrolytic solution. The non-aqueous electrolytic solution includes an electrolyte salt represented by Li(XSO.sub.2NSO.sub.2Y) (where X and Y are any of F, C.sub.nF.sub.2n+1 and (CF.sub.2).sub.m, and (CF.sub.2).sub.m forms a cyclic imide anion), an organic solvent which is capable of dissolving the electrolyte salt, and a polyethylene glycol of which both terminals are not OH. The positive electrode active material includes a chloride of Cu, Bi or Ag, and the negative electrode active material includes lithium.

An alkali metal electrode treatment agent including an acrylate represented by the following general formula (1):

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wherein X, Y and Rf are as defined herein and/or a polymer containing an acrylate represented by the general formula (1) as a part or all of its constituent units. Also disclosed is an electrolytic solution for an alkali metal secondary battery and an alkali metal electrode including the acrylate represented by the general formula (1), an alkali metal secondary battery including the alkali metal electrode, and a module including the alkali metal secondary battery.

Provided herein are energy storage devices. In some cases, the energy storage devices are capable of being transported on a vehicle and storing a large amount of energy. An energy storage device is provided comprising at least one liquid metal electrode, an energy storage capacity of at least about 1 MWh and a response time less than or equal to about 100 milliseconds (ms).

A variety of systems, methods and compositions are disclosed, including, in one method for recycling a spent alkaline battery comprising: dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; extracting zinc sulfate from aqueous solution thereby producing zinc sulfate product and raffinate solution comprising manganese sulfate and potassium sulfate; separating manganese hydroxide from raffinate solution thereby producing manganese sulfate product and aqueous potassium sulfate solution; crystallizing aqueous potassium sulfate solution to produce solid potassium sulfate product. A system for recycling spent alkaline battery comprising: first liquid-solid extraction unit capable of dissolving insoluble metal ions in aqueous solution thereby producing pregnant leach solution; liquid-liquid extraction unit capable of extracting zinc from pregnant leach solution; second liquid-solid extraction unit capable of precipitating manganese hydroxide from raffinate produced by liquid-liquid extraction unit; and third liquid-solid extraction unit capable of crystallizing aqueous potassium sulfate solution produced by second liquid-solid extraction unit.

Provided is a method for fabricating a magnesium-containing electrode by a plating method. In the fabrication process disclosure, a plating solution used in the plating method includes a solvent containing an ether. The solvent includes a first magnesium salt having a disilazide structure represented by a formula (R.sub.3Si).sub.2N and a second magnesium salt that does not have a disilazide structure. In the formula, R represents a hydrocarbon group having 1 or more and 10 or less carbon atoms.

Pressure relief mechanisms can provide an outlet for cathode pressure buildup during battery operation. Mechanical cathode modifications can control cathode interfaces during battery operation. Pressure relief mechanisms and mechanical modifications can be utilized to improve performance, longevity and/or to prevent failure of batteries, such as during cycling of liquid metal batteries.

A positive electrode for a sodium ion secondary battery includes a positive electrode active material that intercalates and deintercalates sodium ions, a conductive assistant, a binder, and a carboxylic acid, the binder containing a vinylidene fluoride-based polymer, the carboxylic acid having at least one of a boiling point and a thermal decomposition point, and whichever of the boiling point and the thermal decomposition point is lower being higher than 150° C. The carboxylic acid is preferably at least one selected from the group consisting of hydroxy acids and polycarboxylic acids.

Articles and methods related to passivation layers on alkali metals are generally described.