Disclosed is a transparent anode thin film comprising a transparent anode active material layer, wherein the transparent anode active material layer comprises a Si-based anode active material having a composition represented by the following [Chemical Formula 1]:
SiN.sub.x  [Chemical Formula 1] (wherein 0<x≤1.5).

Electrolytes for lithium ion batteries with carbon-based, silicon-based, or carbon- and silicon-based anodes include a lithium salt; a nonaqueous solvent comprising at least one of the following components: (i) an ester, (ii) a sulfur-containing solvent, (iii) a phosphorus-containing solvent, (iv) an ether, (v) a nitrile, or any combination thereof, wherein the lithium salt is soluble in the solvent; a diluent comprising a fluoroalkyl ether, a fluorinated orthoformate, a fluorinated carbonate, a fluorinated borate, a fluorinated phosphate, a fluorinated phosphite, or any combination thereof, wherein the lithium salt has a solubility in the diluent at least 10 times less than a solubility of the lithium salt in the solvent; and an additive having a different composition than the lithium salt, a different composition than the solvent, and a different composition than the diluent. In some electrolytes, the nonaqueous solvent comprises an ester.

Manufacturing a lithium-ion battery includes assembling the lithium-ion battery; and performing an initial charging on the lithium-ion battery. The lithium-ion battery includes a positive electrode, a negative electrode, and an electrolyte; the negative electrode contains a negative electrode active material containing a precursor of a silicon material, the precursor having a composition represented by SiO.sub.x where a relationship of 0<x<2 is satisfied. The initial charging includes a first step where the charging is performed to an intermediate voltage at a first current rate, and a second step where the charging is performed from the intermediate voltage to a maximum voltage at a second current rate. The first current rate is lower than 0.5 C; the second current rate is higher than the first current rate; and the intermediate voltage is 3.75 V or higher.

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.

A positive electrode for a secondary battery includes a positive electrode current collector, and a positive electrode mixture layer containing a positive electrode active material and provided on a surface of the positive electrode current collector, wherein the positive electrode active material contains a lithium-containing composite oxide which has a layered structure, and in the lithium-containing composite oxide, nickel occupies 80 atom % or more of a metal other than lithium, and the positive electrode mixture layer has a carbon fiber having an outermost diameter of 5 nm or less, and the carbon fiber is contained by 0.1 parts by mass or less relative to 100 parts by mass of the positive electrode active material.

Silicon particles for use in an electrode in an electrochemical cell are provided. The silicon particles may have outer regions extending about 20 nm deep from the surfaces, the outer regions comprising an amount of aluminum such that a bulk measurement of the aluminum comprises at least about 0.01% by weight of the silicon particles. The bulk measurement of the aluminum may provide the amount of aluminum present at least in the outer regions.

A lithium ion cell includes a ribbon-shaped electrode-separator assembly having an anode, a separator, and a cathode. The electrode-separator assembly has two terminal end faces or two terminal sides. The anode comprises a ribbon-shaped anode current collector having a first longitudinal edge, the cathode comprises a ribbon-shaped cathode current collector having a first longitudinal edge, and the electrode-separator assembly is enclosed in a housing. The first longitudinal edge of the anode current collector protrudes from one of the terminal end faces or terminal sides of the stack and the first longitudinal edge of the cathode current collector protrudes from the other. A contact sheet metal member is in direct contact with a respective longitudinal edge. A part of the housing serves as the contact sheet metal member and/or the contact sheet metal member forms a part of the housing enclosing the electrode-separator assembly.

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.

An electrode for a lithium-ion battery is disclosed, which comprises: a collector comprising a nano-twinned copper foil; and a negative electrode material disposed on the collector, wherein the negative electrode material comprises at least one selected from the group consisting of: silicon, silicon nitride, graphite, graphene, carbon nanotubes, carbon nano-fibers and carbon nano-particles. In addition, a lithium-ion battery comprising the aforesaid electrode is also provided.

The present disclosure provides a negative electrode for an electrochemical cell that cycles lithium ions. The negative electrode may include a negative electroactive material and a lithiation additive. The negative electroactive material may have a first cell voltage window. The lithiation additive may have a second cell voltage window. The second cell voltage window may be less than the first cell voltage window. When the electrochemical cell is operated in the second cell voltage window, the lithiation additive may lithiated the cell.