Disclosed is a positive electrode for a lithium secondary battery and a lithium secondary battery including the same. More particularly, disclosed is a positive electrode for a lithium secondary battery including a sulfur-carbon composite including thermally expanded-reduced graphene oxide as a positive electrode active material and montmorillonite as an additive. The positive electrode for the lithium secondary battery not only has excellent electrochemical reactivity, but also improves the problem due to leaching of lithium polysulfide, thereby improving capacity and lifetime characteristics of the lithium secondary battery.

Disclosed is an electrolyte for a lithium-sulfur battery and a lithium-sulfur battery including the same, more specifically an electrolyte for a lithium-sulfur battery including a lithium salt, a non-aqueous organic solvent, and an additive, wherein the additive includes a sulfide compound. The electrolyte for the lithium-sulfur battery improves the efficiency and stability of the negative electrode, thereby improving the capacity and lifetime characteristics of the lithium-sulfur battery.

An electrode and a method of manufacturing an electrode for a lithium secondary battery comprising a perforated current collector. The perforated current collector is capable of allowing active materials to be bonded through perforations of the perforated current collector, and at the same time, improving the energy density of the battery by reducing the weight even if the wet process and the electrically conductive material and binder, which are essential components of the existing electrode mixture, are excluded. The electrode for the lithium secondary battery comprises a first electrode active material layer; a second electrode active material layer; and a perforated current collector interposed between the first electrode active material layer and the second electrode active material layer and is characterized in that the first electrode active material layer and the second electrode active material layer are combined through perforations of the current collector.

A negative electrode and a lithium-sulfur battery comprising the same are provided. The negative electrode comprises a negative electrode current collector and a protective layer which is disposed on at least one surface of the negative electrode current collector and contains graphene.

An anodeless cell with an anode-side current collector and a cathode active surface that supports a layer of anode material. The cathode active material includes a conductive framework of tangled nanofibers with lumps of amorphous carbon-sulfur and the anode material distributed within them. During cell formation, the anode material of the layer and within the cathode material is electrodeposited on the anode current collector to form the anode. The combined anode material within and on the cathode material is more than is required for anode formation. The excess anode material can be removed, and some can be left in the cell to offset losses due to side reactions.

Electrolytes, anodes, lithium ion cells and methods are provided for preventing lithium metallization in lithium ion batteries to enhance their safety. Electrolytes comprise up to 20% ionic liquid additives which form a mobile solid electrolyte interface during charging of the cell and prevent lithium metallization and electrolyte decomposition on the anode while maintaining the lithium ion mobility at a level which enables fast charging of the batteries. Anodes are typically metalloid-based, for example include silicon, germanium, tin and/or aluminum. A surface layer on the anode bonds, at least some of the ionic liquid additive to form an immobilized layer that provides further protection at the interface between the anode and the electrolyte, prevents metallization of lithium on the former and decomposition of the latter.

Disclosed is a positive electrode for a lithium-sulfur battery, including a current collector; and a positive electrode active material layer on the current collector, wherein the positive electrode active material layer includes a positive electrode active material and a binder, and the positive electrode active material layer has surface properties defined by the following S.sub.a (arithmetic mean surface roughness of the positive electrode) and S.sub.z (maximum height roughness of the positive electrode) ((i) 1 μm≤S.sub.a≤5 μm, (ii) 10 μm≤S.sub.z≤60 μm (wherein S.sub.a is the average value of the distance from the middle surface of the surface irregularity structure of the positive electrode to the highest point and the lowest point of each irregularity part, and S.sub.z means the distance from the lowest point to the highest point of the positive electrode)) and a method for manufacturing the same.

An electrode material for a lithium ion secondary battery and method of forming the same, the electrode material including composite particles, each composite particle including: a primary particle including an electrochemically active material; and an envelope disposed on the surface of the primary particle. The envelope includes turbostratic carbon having a Raman spectrum having: a D band having a peak intensity (I.sub.D) at wave number between 1330 cm.sup.−1 and 1360 cm.sup.−1; a G band having a peak intensity (I.sub.G) at wave number between 1530 cm.sup.−1 and 1580 cm.sup.−1; and a 2D band having a peak intensity (I.sub.2D) at wave number between 2650 cm.sup.−1 and 2750 cm.sup.−1. In one embodiment, a ratio of I.sub.D/I.sub.G ranges from greater than zero to about 1.1, and a ratio of I.sub.2D/I.sub.G ranges from about 0.4 to about 2.

A battery includes an anode having an alkali metal as the active material, a cathode having, for example, iron disulfide as the active material, and an increased electrolyte volume.

In a method of manufacturing an electrochemical cell, a porous or non-porous metal substrate may be provided. A precursor solution may be applied to a surface of the metal substrate. The precursor solution may comprise a chalcogen donor compound dissolved in a solvent. The precursor solution may be applied to the surface of the metal substrate such that the chalcogen donor compound reacts with the metal substrate and forms a conformal metal chalcogenide layer on the surface of the metal substrate. A conformal lithium metal layer may be formed on the surface of the metal substrate over the metal chalcogenide layer.