An electrolyte composition can be capable of becoming molten when heated sufficiently. The electrolyte can include at least one lithium halide salt; and at least one lithium non-halide salt combined with the at least one lithium halide salt so as to form an electrolyte composition capable of becoming molten when above a melting point about 350° C. A lithium halide salt includes a halide selected from F and Cl. A first lithium non-halide salt can be selected from the group consisting of LiVO.sub.3, Li.sub.2SO.sub.4, LiNO.sub.3, and Li.sub.2MoO.sub.4. A thermal battery can include the electrolyte composition, such as in the cathode, anode, and/or separator region therebetween. The battery can discharge electricity by having the electrolyte composition at a temperature so as to be a molten electrolyte.

A heat transfer (exchange) composition comprising a halide salt matrix having dispersed therein nanoparticles comprising elemental carbon in the absence of water and surfactants, wherein said halide is fluoride or chloride, wherein the halide salt may be an alkali halide salt (e.g., lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, sodium chloride, potassium chloride, rubidium chloride, and eutectic mixtures thereof) or an alkaline earth halide salt (e.g., fluoride or chloride salt of beryllium, magnesium, calcium, strontium, or barium), and wherein the nanoparticles comprising elemental carbon may be solid or hollow, and wherein the composition may further include nanoparticles comprising a fissile material (e.g., U, Th, or Pu) dispersed within the composition. Molten salt reactors (MSRs) containing these heat transfer compositions in coolant loops in thermal exchange with a reactor core, as well operation of such MSRs, are also described.

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 heat transfer (exchange) composition comprising a halide salt matrix having dispersed therein nanoparticles comprising elemental carbon in the absence of water and surfactants, wherein said halide is fluoride or chloride, wherein the halide salt may be an alkali halide salt (e.g., lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, sodium chloride, potassium chloride, rubidium chloride, and eutectic mixtures thereof) or an alkaline earth halide salt (e.g., fluoride or chloride salt of beryllium, magnesium, calcium, strontium, or barium), and wherein the nanoparticles comprising elemental carbon may be solid or hollow, and wherein the composition may further include nanoparticles comprising a fissile material (e.g., U, Th, or Pu) dispersed within the composition. Molten salt reactors (MSRs) containing these heat transfer compositions in coolant loops in thermal exchange with a reactor core, as well operation of such MSRs, are also described.

The invention proposes a method and a device (10) for thermal-electrochemical energy storage and energy provision. The device (110) comprises: at least one thermal energy store (118), wherein the thermal energy store (118) comprises at least one heat transport medium (121) and at least one storage medium (119) selected from the group consisting of an electromagnetic storage medium, a thermal storage medium; at least one heating device (134), wherein the heating device (134) is designed to receive the heat transport medium (121) from the thermal energy store (118), to heat this medium and return it to the thermal energy store (118); at least one electrochemical cell (146), wherein the electrochemical cell (146) comprises at least one gas chamber (148), wherein the electrochemical cell (146) further comprises at least one first electrode (150) and at least one second electrode (152): wherein the second electrode (152) is designed as a 3-phase electrode (154), wherein the 3-phase electrode (154) has at least one first phase boundary (156) to the gas chamber (148) and at least one second phase boundary (158) to the electrochemical storage medium (119); wherein the electrochemical cell (146) is designed to electrochemically react the electrochemical storage medium (119); and at east one container (160), wherein the container (160) is designed to receive a supply on the heat transport medium (119), wherein the container (160) is further designed to receive the thermal storage medium (119) from the thermal energy store (118).

A composite solid electrolyte where self-discharge at room temperature is fundamentally prevented by adding a molten salt powder, which is an electric insulator at room temperature, or applying a molten salt passivation layer. The composite solid electrolyte includes: molten salt powder particles having electrical insulating properties at room temperature; and solid electrolyte powder particles on which surfaces thereof the molten salt powder particles are combined.

A molten sodium-based battery comprises a robust, highly Na-ion conductive, zero-crossover separator and a fully inorganic, fully liquid, highly cyclable molten cathode that operates at low temperatures.

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).

An electrolyte includes a composite salt mixture formed from a halogen-free closo-borate salt and a halogenated closo-borate salt. The halogen-free closo-borate salt includes a first cation selected from Li.sup.+, Na.sup.+, Mg.sup.2+, or Ca.sup.2+, and a closo-borate anion with the structure [B.sub.yH.sub.(yz)R.sub.z].sup.2, [CB(.sub.y1)H.sub.(yz)R.sub.z].sup., [C.sub.2B.sub.(y2)H.sub.(yt1)R.sub.t].sup., [C.sub.2B.sub.(y3)H.sub.(yt)R.sub.t].sup., or [C.sub.2B.sub.(y3)H.sub.(yt1)R.sub.t].sup.2, and a second cation selected from Li.sup.+, Na.sup.+, Mg.sup.2+, or Ca.sup.2+,and a halogenated closo-borate anion with the structure [B.sub.yH.sub.(yzi)R.sub.zX.sub.i].sup.2, [CB(.sub.y1)H.sub.(yzi)R.sub.zX.sub.i].sup., [C.sub.2B.sub.(y2)H.sub.(ytj1)R.sub.tX.sub.j].sup., [C.sub.2B.sub.(y3)H.sub.(ytj)R.sub.tX.sub.j].sup., or [C.sub.2B.sub.(y3)H.sub.(ytj1)R.sub.tX.sub.j].sup.2. The parameter y is an integer within a range of 6 to 12, z is an integer within a range of 0 to y, t is an integer within a range of 0 to (y1), z+i is an integer within a range of 0 to y, t+j is an integer within a range of 0 to y1, R is a linear, branched-chain, or cyclic C1-C18 alkyl or fluoroalkyl group, and X is F, Cl, Br, and/or I.

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.