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.

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.

An electrochemical cell including: a negative electrode including calcium and an alkali metal; a positive electrode including one or more elements selected from the group consisting of Al, Si, Zn, Ga, Ge, Cd, In, Sn, Sb, Hg, Tl, Pb, Bi, Te, Bi, Pb, Sb, Zn, Sn and Mg; and an electrolyte including a salt of calcium and a salt of the alkali metal. The electrolyte is configured to allow the cations of the calcium and alkali metal to be transferred from the negative electrode to the positive electrode during discharging and to be transferred from the positive electrode to the negative electrode during charging. The electrolyte exists as a liquid phase and one or both of the negative electrode and the positive electrode exists as liquid or partially liquid phases at operating temperatures of the electrochemical cell.

A electrochemical storage device, referred to herein as a radical-ion battery, is described. The radical-ion battery includes an electrolyte, first free radicals, and second free radicals, wherein the first free radicals and the second free radicals are different chemical species. The radical-ion battery also includes a separator that allows select ions to pass therethrough, but separates the electrolyte from the second free radicals.

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 an electrolyte configured to transition to a liquid phase in an operating temperature range. The electrolyte includes at least one of an alkali oxide, boron oxide, a carbonate, a phosphate, and a group III-X transition metal oxide.

Square section liquid metal batteries (LMBs) with a grid device to suppress instabilities of fluids. The LMBs include a shell, negative current collector, negative material, metallic nets/plates, grid device, electrolyte, positive material, rectangular holes on partitions of grid device, and positive current collector. The positive material, electrolyte, and negative material are filled in the shell and automatically stratified from bottom to top according to the density from large to small. The negative current collector is linked with negative material, and the positive current collector is linked with positive material. The grid device is composed of partitions which cross each other and pass through the negative material, the electrolyte vertically in sequence, and extend inside the positive material. There are rectangular holes opened on the grid device, and the vertical height of each rectangular hole is larger than the biggest displacement of electrolyte during charging and discharging processes.

The present disclosure relates to rechargeable electrochemical battery cells (molten air batteries). The cells use air and a molten electrolyte, are quasi-reversible (rechargeable) and have the capacity for multiple electrons stored per molecule and have high intrinsic electric energy storage capacities. The present disclosure also relates to the use of such in a range of electronic, transportation and power generation devices, such as greenhouse gas reduction applications, electric car batteries and increased capacity energy storage systems for the electric grid.

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.

Cell and batteries containing them employing a cathode having a intercalating metal oxide in combination with a sodium metal haloaluminate. At operating temperatures, the positive electrode (cathode) of the invention comprises electroactive cathode material permeated with and in physical and electrical contact with the sodium metal haloaluminate catholyte. The positive and negative electrodes are separated with a solid alkali metal conducting electrolyte. The intercalating metal oxice is not in direct physical contact with the solid electrolyte. Electric and ionic conductivity between the solid electrolyte and the positive electrode is mediated by the sodium haloaluminate catholyte. Batteries of the invention are useful for bulk energy storage, particularly for electric utility grid storage, as well as for electric vehicle propulsion.