Tin-containing carbon fibers may be produced by centrifugal spinning of a precursor composition that includes a base polymer and a tin-containing compound. The produced fibers are heated at a temperature sufficient to convert at least a portion of the base polymer in the collected fibers into carbon fibers comprising tin.

A negative electrode for a rechargeable lithium battery includes a negative active material including a metal-based material, crystalline carbon, and amorphous carbon, wherein an amount of the crystalline carbon is greater than that of the amorphous carbon. A rechargeable lithium battery includes the negative electrode including the negative active material.

Methods for pre-lithiating negative electrodes for lithium-ion electrochemical cells (e.g., batteries) are provided. The methods include disposing a lithium metal source comprising a layer of lithium metal adjacent to a surface of a pre-fabricated negative electrode. The lithium metal source and electrode are heated (e.g., to a temperature of ≧about 100° C.) to transfer a quantity of lithium to the pre-fabricated negative electrode. This lithiation process adds excess active lithium capacity that enables replacement of irreversibly lost lithium during cell formation and cell aging, thus leading to increased battery capacity and improved battery life. The methods may be batch or continuous.

The present application is generally directed to composites comprising a hard carbon material and an electrochemical modifier. The composite materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed composite materials are also disclosed.

An electrode for a metal-ion battery is provided wherein the active layer of the electrode comprises a plurality of porous particles comprising an electroactive material selected from silicon, germanium, tin, aluminium and mixtures thereof and a plurality of carbon particles selected from one or more of graphite, soft carbon and hard carbon. The ratio of the D.sub.50 particles size of the carbon particles to the D.sub.50 particle diameter of the porous particles is in the range of from 1.5 to 30. Also provided are rechargeable metal-ion batteries comprising said electrode and compositions of porous particles and carbon particles which may be used to prepare the active layer of said electrode.

A secondary battery capable of improving cycle characteristics is provided. An anode includes: an anode active material layer on an anode current collector, the anode active material layer including a plurality of anode active material particles, in which the average particle area of the plurality of anode active material particles observed from a surface of the anode active material layer is within a range of 1 μm.sup.2 to 60 μm.sup.2 both inclusive.

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The separator includes a substrate layer and a surface layer formed on at least one principal plane of the substrate layer, the surface layer contains polyvinylidene fluoride and an inorganic material particle, and an amount of deformation against pressure of the surface layer is larger than that of the substrate layer.

A nonaqueous electrolyte secondary battery of an embodiment includes an exterior member, a cathode including a cathode active material layer housed in the exterior member, an anode including an anode active material layer housed in the exterior member and spatially separated from the cathode by a separator, and a nonaqueous electrolyte filled in the exterior member. The cathode active material layer contains lithium-copper oxide and copper oxide. A peak intensity ratio d(002)/d(010) between a plane index d(010) derived from the lithium-copper oxide and a plane index d(002) derived from the copper oxide is not lower than 0.1 and not higher than 0.5 at an X-ray diffraction peak.

The present invention relates to: an electrolyte for a rechargeable lithium battery, the electrolyte including a non-aqueous organic solvent, a lithium salt, and an electrolyte additive for a rechargeable lithium battery, the electrolyte additive including a compound represented by Chemical Formula 1; and a rechargeable lithium battery comprising the electrolyte for a rechargeable lithium battery. Chemical Formula 1 is as defined in the specification.

Functionalized Group IVA particles, methods of preparing the Group IVA particles, and methods of using the Group IVA particles are provided. The Group IVA particles may be passivated with at least one layer of material covering at least a portion of the particle. The layer of material may be a covalently bonded non-dielectric layer of material. The Group IVA particles may be used in various technologies, including lithium ion batteries and photovoltaic cells.