A negative electrode material that is used for a negative electrode of a lithium secondary battery containing a non-aqueous electrolyte solution, includes: a first layer that contains lithium metal as a negative electrode active material; and a second layer that is arranged on at least one surface of the first layer. The second layer consists of a compound represented by a general formula M.sub.xA.sub.y (M is an element selected from a group consisting of Al, In, Mg, Ag, Si, and Sn, and A is an element selected from a group consisting of O, N, P, and F, and 0.3<x/y<3). The second layer has a thickness of 100 nm or less.

A negative electrode for a lithium secondary battery includes a negative electrode current collector and a negative electrode layer. The negative electrode layer includes a composite layer and a single lithium metal layer. The composite layer includes, as a negative electrode active material, an alloy of lithium metal and dissimilar metal. The composite layer and the single lithium metal layer are arranged in this order from the negative electrode current collector. The dissimilar metal is an element that is able to form a solid solution with the lithium metal or an element that is able to form an intermetallic compound with the lithium metal.

A lithium secondary battery includes a positive electrode, and a negative electrode in which deposition and dissolution reactions of lithium metal occur. The negative electrode includes a negative electrode layer. The negative electrode layer contains, as a negative electrode active material, an alloy of the lithium metal and dissimilar metal. An element percentage of lithium element in the alloy is 40.00 atomic % or more and 99.97 atomic % or less when the lithium secondary battery is fully charged.

Electrolyte materials for use in electrochemical cells, electrochemical cells comprising the same, and methods of making such materials and cells, are generally described. In some embodiments, the materials, processes, and uses described herein relate to electrochemical cells comprising sulfur and lithium such as, for example, lithium sulfur batteries.

A compound represented by the Formula 1 and having an argyrodite-type crystal structure:
Li.sub.aM1.sub.xM2.sub.wPS.sub.yM3.sub.z  Formula 1
wherein M1 is at least one element of Group 2 or Group 11 of the periodic table, M2 is at least one metal element other than Li of Group 1 of the periodic table, M3 is at least one element of Group 17 of the periodic table, and wherein 4≤a≤8, 0<x<0.5, 0≤w<0.5, 3≤y≤7, and 0≤z≤2.

The present invention provides an anode composition comprising (i) a core material (10) comprising a microparticle; (ii) a lithium alloy of said microparticle (14) on a surface of said core material (10); and (iii) a solid electrolyte interface (“SEI”) comprising (a) a LiF and (b) a polymer. The microparticle comprises Si, Al, Bi, Sn, Zn, or a mixture thereof. The present invention also relates to an electrolyte comprising a high lithium fluoride salt concentration in a low reduction potential solvent that is used produce the solid electrolyte interface comprising LiF and a polymer. The anode composition of the invention has an initial coulombic efficiency of at least 90%, a cycling coulombic efficiency of at least 99%, or both.

The invention relates to electrochemical current sources, more particularly to metal-air current sources, and even more particularly to lithium-air current sources and their electrodes. A cathode comprises a base made of a porous electrically conducting material that is permeable to molecular oxygen, the working surface of which has a copolymer applied thereto, which is produced by the copolymerization of a monomeric transition metal coordination complex having a Schiff base and a thiophene group monomer. The monomeric transition metal coordination complex having a Schiff base can be, for example, a compound of the [M(R,R-Salen)], [M(R,R-Saltmen)] or [M(R,R-Salphen)] type, and the thiophene group monomer can be a compound selected from a thiophene group consisting of 3-alkylthiophenes, 3,4-dialkylthiophenes, 3,4-ethylenedioxythiophene or combinations thereof. A current source comprises the described cathode and an anode made from an active metal, in particular lithium, wherein the cathode and the anode are separated by an electrolyte containing ions of the metal from which the anode is made. It has been established that in this system, the copolymer exhibits the properties of an effective catalyst. The technical result is an increase in the specific energy, specific power and number of charge and discharge cycles of a metal-air current source.

A solid state battery is described, which has a negative electrode having a negative electrode active material layer including silicon (Si) as a negative electrode active material. The Si may be present as particles, e.g., microparticles, having an average particle size (D50) of 0.1 μm to 10 μm. The negative electrode active material layer may include the silicon (Si) in an amount of 75 wt % or more, 95 wt % or more, 99 wt % or more, or 99.9 wt % or more, based on 100 wt % of the negative electrode active material layer. The negative electrode active material layer can be free or substantially free of conductive material, carbon, solid state electrolyte, and/or binder. Preferably, after charge/discharge cycles, the negative electrode active material layer forms densified and interconnected large particles of Li—Si alloy, e.g., the Li—Si alloy may have at least one columnar structure and at least one void.

A component for a lithium battery including a first layer including a lithium garnet having a porosity of 0 percent to less than 25 percent, based on a total volume of the first layer; and a second layer on the first layer and having a porosity of 25 percent to 80 percent, based on a total volume of the second layer, wherein the second layer is on the first layer and the second layer has a composition that is different from a composition of the first layer.

A protected anode, an electrochemical device including the same, and a method of preparing the electrochemical device. The protected anode may include: an anode layer; and a protective layer including an oxide represented by Formula 1, on the anode layer:

##STRFormula 1##

In Formula 1, A is at least one of Ge, Sb, Bi, Se, Sn, or Pb; M is at least one of In, Tl, Sb, Bi, S, Se, Te, or Po; A and M are different from each other; and 0<x<100 and 0<y<100.