Abstract: Electrolytes for use in commercially viable, rechargeable lithium metal batteries are described. The electrolytes contain one or more lithium salts, one or more organic solvents, and one or more additives. The electrolytes allow for reversible deposition and dissolution of lithium metal. Specific additives or additive combinations dramatically improved cycle life, decrease cell swelling, and/or lower cell impedance.

Abstract: A secondary cell comprising a positive cathode electrode of capacity P (mAh) in communication with a liquid or gel electrolyte; an negative anode electrode of capacity N (mAh) in communication with the electrolyte; and a separator permeable to at least one mobile species which is redox-active at least one of the anode and the cathode; designed and constructed such that the anode capacity N is smaller than that of the cathode capacity P, hence N/P<0.9.

Abstract: A multi-electrode device that includes an anode electrode, a cathode electrode, and a gate electrode situated between the anode and cathode, and having an electrolyte. The multi-electrode device can be a secondary (rechargeable) electrochemical cell. The gate electrode is permeable to at least one mobile species which is redox-active at at least one of the anode and cathode. The gate electrode has a resistance that is lower than that of a conductive non-uniform morphological feature that could be grown on the anode. The gate electrode provides the ability to avoid, recognize, and remove the presence of such non-uniform morphological features, and provides an electrical electrode that can be used to remove such non-uniform morphological features.

Abstract: A non-aqueous Magnesium electrolyte comprising: (a) at least one organic solvent; (b) at least one electrolytically active, soluble, inorganic Magnesium (Mg) salt complex represented by the formula: MgaZbXc wherein a, b, and c are selected to maintain neutral charge of the molecule, and Z and X are selected such that Z and X form a Lewis Acid, and 1?a?10, 1?b?5, and 2?c?30. Further Z is selected from a group consisting of aluminum, boron, phosphorus, titanium, iron, and antimony; X is selected from the group consisting of I, Br, Cl, F and mixtures thereof. Rechargeable, high energy density Magnesium cells containing an cathode, an Mg metal anode, and an electrolyte of the above-described type are also disclosed.

Abstract: Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

Abstract: A secondary cell comprising a positive cathode electrode of capacity P (mAh) in communication with a liquid or gel electrolyte; an negative anode electrode of capacity N (mAh) in communication with the electrolyte; and a separator permeable to at least one mobile species which is redox-active at least one of the anode and the cathode; designed and constructed such that the anode capacity N is smaller than that of the cathode capacity P, hence N/P<0.9.

Abstract: A secondary cell comprising a positive cathode electrode of capacity P (mAh) in communication with a liquid or gel electrolyte; an negative anode electrode of capacity N (mAh) in communication with the electrolyte; and a separator permeable to at least one mobile species which is redox-active at least one of the anode and the cathode; designed and constructed such that the anode capacity N is smaller than that of the cathode capacity P, hence N/P<0.9.

Abstract: A multi-electrode device that includes an anode electrode, a cathode electrode, and a gate electrode situated between the anode and cathode, and having an electrolyte. The multi-electrode device can be a secondary (rechargeable) electrochemical cell. The gate electrode is permeable to at least one mobile species which is redox-active at at least one of the anode and cathode. The gate electrode has a resistance that is lower than that of a conductive non-uniform morphological feature that could be grown on the anode. The gate electrode provides the ability to avoid, recognize, and remove the presence of such non-uniform morphological features, and provides an electrical electrode that can be used to remove such non-uniform morphological features.

Abstract: A rechargable magnesium battery having an non-aqueous electrolyte is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

Abstract: Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

Abstract: A multi-electrode device that includes an anode electrode, a cathode electrode, and a gate electrode situated between the anode and cathode, and having an electrolyte. The multi-electrode device can be a secondary (rechargeable) electrochemical cell. The gate electrode is permeable to at least one mobile species which is redox-active at at least one of the anode and cathode. The gate electrode has a resistance that is lower than that of a conductive non-uniform morphological feature that could be grown on the anode. The gate electrode provides the ability to avoid, recognize, and remove the presence of such non-uniform morphological features, and provides an electrical electrode that can be used to remove such non-uniform morphological features.

Abstract: Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqeuous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

Abstract: A compound of formula Ab?MgaMbXy or Ab?MgaMb(XOz)y for use as electrode material in a magnesium battery is disclosed, wherein A, M, X, b?, a, b, y, and z are defined herein.

Abstract: A magnesium battery electrode assembly is described, including a current collector comprising a metal, an overlayer material on the metal and an electrode layer comprising an electrode active material disposed on the current collector. The overlayer material passivates the metal, or inhibits a corrosion reaction that would occur between the metal and an electrolyte in the absence of the overlayer material.

Abstract: An electrolyte for use in electrochemical cells is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

Abstract: A non-aqueous Magnesium electrolyte comprising: (a) at least one organic solvent; (b) at least one electrolytically active, soluble, inorganic Magnesium (Mg) salt complex represented by the formula: MgaZbXc wherein a, b, and c are selected to maintain neutral charge of the molecule, and Z and X are selected such that Z and X form a Lewis Acid, and 1?a?10, 1?b?5, and 2?c?30. Further Z is selected from a group consisting of aluminum, boron, phosphorus, titanium, iron, and antimony; X is selected from the group consisting of I, Br, Cl, F and mixtures thereof. Rechargeable, high energy density Magnesium cells containing an cathode, an Mg metal anode, and an electrolyte of the above-described type are also disclosed.

Abstract: An electrolyte for use in electrochemical cells is provided. One type of non-aqueous Magnesium electrolyte comprises: at least one organic solvent; at least one electrolytically active, soluble, inorganic Magnesium salt complex represented by the formula: MgnZX3+(2*n), in which Z is selected from a group consisting of aluminum, boron, phosphorus, titanium, iron, and antimony; X is a halogen and n=1-5. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2 and total water content of <200 ppm. The use of this electrolyte promotes the electrochemical deposition and dissolution of Mg from the negative electrode without the use of any additive. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described. Rechargeable, high energy density Magnesium cells containing a cathode, an Mg metal anode, and an electrolyte are also disclosed.

Abstract: Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

Abstract: An electrolyte for use in electrochemical cells is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

Abstract: Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.