One or more interfacial layers in contact with a solid-state electrolyte and hybrid electrolyte materials. Interfacial layers comprise inorganic (e.g., metal oxides and soft inorganic materials) or organic materials (e.g., polymer materials, gel materials and ion-conducting liquids). The interfacial layers can improve the electrical properties (e.g., reduce the impedance) of an interface between an a cathode and/or anode and a solid-state electrolyte. The interfacial layers can be used in, for example, solid-state batteries (e.g., solid-state, ion-conducting batteries).

An electrode includes at least magnesium, carbon, oxygen, sulfur, and halogen. The electrode also has a surface exhibiting a single peak derived from magnesium in the range of 40 eV to 60 eV.

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).

It is an object of the present invention to provide an electrolytic solution having high oxidation decomposition potential, where dissolution and deposition of magnesium proceed repeatedly and stably, using a non-nucleophilic alkoxide-type magnesium salt.

The present invention relates to (1) an electrolytic solution for a magnesium battery comprising a mixture of a compound represented by the following general formula (I), a Lewis acid and a solvent:

##STR00001## (2) an electrochemical device comprising the electrolytic solution, a positive electrode and a negative electrode, and (3) a compound represented by the following general formula (I′):

##STR00002##

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.

A battery has a cathode, an anode and an electrolyte, with the cathode having a cathode current collector and a cathode material. The cathode material has a cathode active material, which is capable of reversibly intercalating and deintercalating first metal ions. The electrolyte has a solvent capable of dissolving the first metal ions and second metal ions that can be reduced to a metal during a charge cycle and be oxidized from the metal to the dissolved second metal ions during a discharge cycle. The cathode current collector has an electrochemically inert carrier and graphite. The carrier is wrapped by the graphite. The cathode current collector provided has good corrosion resistance and the battery has a long floating charge life and a low cost.

A method for production of a magnesium battery with low impedance is provided. A cell is constructed comprising an uncoated current collector anode, an electrolyte system comprising a non-aqueous solvent and a magnesium salt soluble in the non-aqueous solvent, and a cathode. The cell is charged to electrodeposit magnesium metal unto the uncoated current collector to obtain an anode having magnesium metal as the active material. Also provided are rechargeable magnesium batteries obtained by the method.

A rechargeable battery cell has an organic-liquid electrolyte contacting a dendrite free alkali-metal anode. The alkali-metal anode may be a liquid at the operating temperature that is immobilized by absorption into a porous membrane. The alkali-metal anode may be a solid that wets a porous-membrane separator, where the contact between the solid alkali-metal anode and the liquid electrolyte is at micropores or nanopores in the porous-membrane separator. The use of a dendrite-free solid lithium cell was demonstrated in a symmetric cell with a porous cellulose-based separator membrane. A K.sup.+-ion rechargeable cell was demonstrated with a liquid K—Na alloy anode immobilized in a porous carbon membrane using an organic-liquid electrolyte with a Celgard® or glass-fiber separator.

A calcium-based secondary cell including a negative electrode that includes a negative-electrode active material, a positive electrode that includes a positive-electrode active material, an electrolyte arranged between the negative electrode and the positive electrode, and a temperature control element. The negative-electrode active material is capable of accepting and releasing calcium ions, and the positive-electrode active material is capable of accepting and releasing calcium ions. The electrolyte includes calcium ions and an electrolyte medium, and is not solid at a temperature of about 20° C. and a pressure of about 1 atm. The electrolyte medium includes a non-aqueous solvent.

This invention provides a non-aqueous electrolyte magnesium secondary battery comprising a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, the non-aqueous electrolyte comprising [N(SO.sub.2CF.sub.3).sub.2].sup.− as an anion, and Mg.sup.2+ and/or an organic onium cation as a cation.