A heat resistant battery includes a positive electrode including a positive electrode current collector and a positive electrode active material fixed on the positive electrode current collector, wherein the positive electrode active material includes a sodium-containing transition metal compound capable of electrochemically storing and releasing a sodium ion; a negative electrode including a negative electrode current collector and a negative electrode active material fixed on the negative electrode current collector, wherein the negative electrode active material contains at least one selected from the group consisting of a sodium-containing titanium compound and a non-graphitizable carbon, each of the sodium-containing titanium compound and the non-graphitizable carbon capable of storing and releasing a sodium ion at a lower potential than a potential of the sodium-containing transition metal compound; and a sodium ion-conductive electrolyte provided at least between the positive electrode and the negative electrode, wherein the sodium ion-conductive electrolyte includes a salt of an organic cation having a pyrrolidinium skeleton and a bis(perfluoroalkyl sulfonyl)imide anion.

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).

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).

The disclosure provides seals for devices that operate at elevated temperatures and have reactive metal vapors, such as lithium, sodium or magnesium. In some examples, such devices include energy storage devices that may be used within an electrical power grid or as part of a standalone system. The energy storage devices may be charged from an electricity production source for later discharge, such as when there is a demand for electrical energy consumption.

A battery system that exchanges energy with an external device is provided. The battery system includes a positive electrode having a first metal or alloy, a negative electrode having a second metal or alloy, and an electrolyte including a salt of the second metal or alloy. The positive electrode, the negative electrode, and the electrolyte are in a liquid phase at an operating temperature during at least one portion of operation. The positive electrode is entirely in a liquid phase in one charged state and includes a solid phase in another charged state. The solid phase of the positive electrode includes a solid intermetallic formed by the first and the second metals or alloys. Methods of storing electrical energy from an external circuit using such a battery system are also provided.

An improved alkali metal halide cell including an anode module having at least (i) one planar module including a porous assembly and (ii) that encloses an active anode material in an anode reservoir; and a cathode having active cathode material; where the porous assembly is coated with a thin ion-conducting layer that separates the active anode material enclosed within the anode module from the cathode material, and the anode and cathode are contained in a housing having one or more compartments.

Disclosed herein are methods and systems for monitoring and/or regulating energy storage devices. Examples of such monitoring and/or regulating include cell balancing, dynamic impedance control, breach detection and determination of state of charge of energy storage devices.

Apparatus and methods to reduce granule disruption during manufacture of electrochemical cells, such as a metal halide electrochemical cell, are provided. In one embodiment, a current collector can include a diffuser strip extending beneath an aperture configured to receive an injection stream of molten electrolyte. The diffuser strip can be configured to dissipate an injection stream of molten electrolyte when the molten electrolyte is injected into an electrochemical cell. In this way, disruption of a granule bed by the injection of the molten electrolyte during manufacture of the electrochemical cell can be reduced.

An additive that is added to the NaAlX.sub.4 electrolyte for use in a ZEBRA battery (or other similar battery). This additive has a moiety with a partial positive charge (+) that attracts the negative charge of the [AlX.sub.4].sup. moiety and weakens the ionic bond between the Na.sup.+ and [AlX.sub.4].sup. moieties, thereby freeing some Na.sup.+ ions to transport (move). By using a suitable NaAlX.sub.4 electrolyte additive, the battery may be operated at much lower temperatures than are typical of ZEBRA batteries (such as, for example, at temperatures between 150 and 200 C.). Additionally, the additive also lowers the viscosity of the electrolyte solution and improves sodium conductivity. Non-limiting examples of the additive SOCl.sub.2, SO.sub.2, dimethyl sulfoxide (DMSO, CH.sub.3SOCH.sub.3), CH.sub.3S(O)Cl, SO.sub.2Cl.sub.2. A further advantage of using this additive is that it allows the use of a NaSICON membrane in a ZEBRA-type battery at lower temperatures compared to a typical ZEBRA battery.

The present disclosure provides an energy storage device comprising at least one electrochemical cell comprising a negative current collector, a negative electrode in electrical communication with the negative current collector, an electrolyte in electrical communication with the negative electrode, a positive electrode in electrical communication with the electrolyte and a positive current collector in electrical communication with the positive electrode. The negative electrode comprises an alkali metal. Upon discharge, the electrolyte provides charged species of the alkali metal. The positive electrode can include a Group IIIA, IVA, VA and VIA of the periodic table of the elements, or a transition metal (e.g., Group 12 element).