Articles and methods related to passivation materials on alkaline earth metals are generally described.

A rechargeable sodium-ion cell, comprising an anode, a cathode, a separator that electronically isolates the anode from the cathode, and an electrolyte in ionic contact with the anode active and the cathode, wherein the anode comprises a graphite or carbon material having expanded inter-graphene planar spaces with an inter-planar spacing d.sub.002 from 0.43 nm to 3.0 nm, as measured by X-ray diffraction, and the expanded inter-graphene planar spaces store sodium ions to a specific capacity no less than 150 mAh/g when the cell is in a charged state. Also provided is a method of producing such an anode and sodium-ion cell.

Disclosed are a system and methods for preventing dendrite growth in an electrochemical cell through the use of a protective layer. The electrochemical cell may comprise an anode, a cathode, an electrolyte, and a protective layer, wherein the protective layer is capable of producing a voltage. The voltage produced can selectively shield metal ions from certain regions of the protective layer. This shielding can result in a more uniform flux of metal ions being transferred across the electrode-electrolyte interface in subsequent electrodeposition and electrodissolution processes. As a result, an electrode with such a protective layer can exhibit improved performance and durability, including markedly lower overpotentials and largely improved metal (e.g., lithium) retention.

Disclosed is a metal anode, including a metal anode body (10) and a protective layer (11) formed on one or two side surfaces of the metal anode body (10). The protective layer (11) includes a coordination polymer having an unsaturated metal site or a complexation product formed by complexation between the coordination polymer having the unsaturated metal site and anions of battery electrolyte salt. The coordination polymer uses zirconium, aluminum, or iron as a center and uses R—X.sub.n as an organic ligand, R is n-valent hydrocarbyl, substituted hydrocarbyl, or hydrocarboxy, n is an integer in a range of 1 to 4, X is an oxygen-containing functional group capable of forming metal-oxygen chemical bond with the metal anode body (10), and the metal-oxygen chemical bond is formed between metal atoms on a surface of the metal anode body (10) and oxygen atoms in the X group.anodeanode.

A solid-state sodium-carbon dioxide battery is provided. The solid-state sodium-carbon dioxide battery comprises a positive electrode, a negative electrode, and an inorganic solid-state electrolyte disposed between the positive electrode and the negative electrode, wherein the positive electrode can catalyze the reaction of sodium ions and carbon dioxide, the negative electrode comprises sodium.

Novel, rechargeable magnesium/magnesium sulfide batteries are disclosed therein, having energy density competitive with lithium batteries, high cycle life, land lower cost. Production method of stabilized MgS is also described, as well as various cells' constructions.

A negative electrode for a lithium metal battery which includes: a current collector; a negative electrode active material layer formed on the surface of a current collector; a heat conductive layer formed on a surface of the negative electrode active material layer wherein the heat conductive layer comprises a heat conductive material having a heat conductivity of 25 W/m.Math.K to 500 W/m.Math.K; and a protective layer formed on a surface of the heat conductive layer, wherein the protective layer includes at least one of a porous polymer layer and a ceramic layer. An electrochemical device including the negative electrode for a lithium metal battery. The negative electrode for a lithium metal battery includes a heat conductive layer and a protective layer, and can inhibit growth of lithium dendrite in a negative electrode for a lithium metal battery and improve the cycle life of an electrochemical device.

An electrolyte composition for an anode-free metal battery cell, wherein the metal is an alkali metal, an alkaline earth metal, or a metal of Group IIIa of the periodic table, including a first solvent, a salt of the alkali metal, the alkaline earth metal or the metal of Group IIIa of the periodic table, the salt being soluble in the first solvent, and an additive. The concentration of the salt in the electrolyte is between 2 M and 3 M, and the additive is a perfluorinated organic compound including at least one halogen atom. The halogen is chlorine, bromine or iodine. An anode-free metal battery cell can include the electrolyte composition.

The present invention provides a magnesium anode and an electrochemical cell comprising the anode.

Provided is a negative electrode active material that contains silicon clathrate II and that is suitable for a negative electrode of a lithium ion secondary battery. The negative electrode active material includes a silicon material in which silicon clathrate II represented by composition formula Na.sub.xSi.sub.136 (0≤x≤10) is contained and a volume of a pore having a diameter of not greater than 100 nm is not less than 0.025 cm.sup.3/g.