An electrochemical cell includes a positive electrode, a negative electrode, an electrolyte disposed between the positive electrode and the negative electrode, and an ion-conducting composite membrane disposed between the positive electrode and the negative electrode. The composite membrane includes a porous substrate having pores and a porosity from about 5 vol % to about 80 vol %, and a selective ion-conductive filler disposed at least partially within the pores. The filler includes an intercalation material. Methods of making the ion-conducting composite membrane and using an electrochemical cell having the ion-conducting composite membrane are also provided.

An electrochemical cell includes a negative electrode comprising a first active metal, a positive electrode comprising a second active metal, and an electrolyte comprising salts of the two active metals, a salt of the cathodic metal and a salt of the anodic metal. In operation, the electrolyte composition varies such that in a charging mode the salt of the anodic salt decreases, while the salt of the cathodic salt increases, and in a discharging mode the salt of the anodic salt increases, while the salt of the cathodic salt decreases. The cell is operational for both storing electrical energy and as a source of electrical energy as part of an uninterruptible power system. The cell is particularly suited to store electrical energy produced by an intermittent renewable energy source.

A substrate-free, self-supporting and/or binder-free silicon material, as well as related articles, systems and methods are disclosed. The silicon material can have a relatively large empty volume, and/or a relatively low density. Exemplary articles include battery electrodes, such as rechargeable metal ion battery electrodes. Exemplary systems include batteries, such as rechargeable metal ion batteries.

A non-aqueous electrolyte solution for a battery, includes: an additive A which is at least one selected from the group consisting of compounds represented by the following Formula (A); an additive B which is at least one selected from the group consisting of lithium monofluorophosphate and lithium difluorophosphate; and an additive C which is at least one selected from the group consisting of compounds containing a sulfur-oxygen bond. In Formula (A), R.sup.1 represents a fluorine atom, or a fluorinated hydrocarbon group having from 1 to 6 carbon atoms; and each of R.sup.2 to R.sup.4 independently represents a hydrogen atom, a fluorine atom, a hydrocarbon group having from 1 to 6 carbon atoms, or a fluorinated hydrocarbon group having from 1 to 6 carbon atoms. ##STR00001##

An electrochemical cell includes a bifunctional air cathode, an anode, and a ceramic electrolyte separator disposed substantially between the bifunctional air cathode and the anode. The anode includes a solid metal and a liquid electrolyte phase. The liquid electrolyte phase includes at least one of an alkali oxide, boron oxide, a group V transition metal oxide, and a group VI transition metal oxide.

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 disclosure relates to solid-phase and molten metal phosphorothioates useful as electrolytes, batteries comprising solid-phase and molten metal phosphorothioates, and methods of making solid-phase and molten metal phosphorothioates.

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).