The present invention relates to a lithium secondary battery including a pre-lithiated carbon-based negative electrode, a positive electrode, a separator, and an inorganic electrolyte represented by the following Formula 1 and a method of preparing the same.

LiMX_n(SO.sub.2)  [Formula 1]

In Formula 1, M is at least one metal selected from an alkali metal, a transition metal, and a post-transition metal, X is a halogen element, and n is an integer of 1 to 4.

A positive electrode active material for a secondary battery is provided. The positive electrode active material being a lithium cobalt-based oxide includes a doping element M. A lithium cobalt-based oxide particle containing the doping element M in an amount of 3,000 ppm or more, wherein in a bulk portion corresponding to 90% of a core side among the radius from a core of the particle to a surface thereof, the doping element M in the lithium cobalt-based oxide particle is contained at a constant concentration, and in a surface portion from the surface of the particle to 100 nm in a core direction, the doping element M is contained at a concentration equal to or higher than that in the bulk portion and has a concentration in which the concentration thereof is gradient gradually decreased in the core direction from the surface of the particle.

The present invention relates to a method for lithiation of an intercalation-based anode or a non-reactive plating-capable foil or a reactive alloy capable anode, whereby utilization of said lithiated intercalation-based anode or a plating-capable foil or reactive alloy capable anode in a rechargeable battery or electrochemical cell results in an increased amount of lithium available for cycling, and an improved reversible capacity during charge and discharge.

Disclosed is a method of manufacturing a secondary battery, the method including: manufacturing a pre-lithiation cell including a negative electrode and a lithium metal counter electrode and pre-lithiating the negative electrode by charging the pre-lithiation cell; separating the pre-lithiated negative electrode from the pre-lithiation cell and manufacturing an electrode assembly including the pre-lithiated negative electrode and a positive electrode; impregnating the electrode assembly with an electrolyte; activating the impregnated electrode assembly by performing a first charging the impregnated electrode assembly; removing gas generated in the activation; discharging the activated electrode assembly immediately after removing the gas; and performing a second charging on the discharged electrode assembly.

A method of manufacturing a negative electrode, which includes: applying a negative electrode slurry on a negative electrode current collector and subjecting the applied negative electrode slurry to a first roll-pressing to form a negative electrode active material layer; pre-lithiating the negative electrode active material layer to form a pre-lithiated negative electrode active material layer; and subjecting the pre-lithiated negative electrode active material layer to a second roll-pressing, wherein the negative electrode active material layer includes a silicon-based active material, and a ratio (p.sub.1/p.sub.2) of porosity (p.sub.1) of negative electrode active material layer after the first roll-pressing to porosity (p.sub.2) of negative electrode active material layer after the second roll-pressing is in a range of 1.05 to 1.65.

A method for pre-lithiation of a negative electrode including the steps of: interposing a separator between a lithium ion-supplying metal sheet and a negative electrode to prepare a simple cell; dipping the simple cell in an electrolyte for pre-lithiation; and disposing the simple cell dipped in the electrolyte for pre-lithiation between two polymer pads, and carrying out electrochemical charging, while pressurizing the outside of the two polymer pads, to perform pre-lithiation of the negative electrode. Each of the polymer pads has a thickness of 60% to 90% of a thickness of a corresponding jig of the pair of jigs. A pre-lithiated negative electrode and a lithium secondary battery including the pre-lithiated negative electrode are also disclosed.

A method of manufacturing a negative electrode wherein, in the pre-lithiation of a negative electrode structure including a negative electrode active material layer formed therein through electrochemical charging in a roll-to-roll manner, the negative electrode active material layer is divided into a central part and a side part. The charge current applied to the central part is higher than the charge current applied to the side part. In addition, in the method of manufacturing the negative electrode a pre-lithiation section is divided into a first section and a second section, the central part is electrochemically charged in the first section, the side part is electrochemically charged in the second section, and the central part and the side part are alternately electrochemically charged in one or more cycles.

The present disclosure belongs to the technical field of lithium battery material, and relates to a negative electrode material, a method therefor and use thereof, the method comprises the following step: conducting a lithiation treatment on a negative electrode raw material in a lithiation solution; the lithiation solution comprises Li- aromatic composition; wherein the aromatic composition comprises unsubstituted aromatic compounds and substituted aromatic compounds; or the aromatic composition comprises at least two substituted aromatic compounds. The negative electrode material, method therefor and use thereof provided by the present disclosure can improve the depth and efficiency of lithium intercalation, reduce the loss of the irreversible capacity and improve the capacity of batteries.

A method of manufacturing a negative electrode includes providing a negative electrode roll on which a negative electrode structure including a negative electrode current collector, a first negative electrode active material layer formed on one side of the negative electrode current collector, and a second negative electrode active material layer formed on the other side of the negative electrode current collector is wound, preparing a pre-lithiation bath including an impregnation section and a pre-lithiation section and containing a pre-lithiation solution, unwinding the negative electrode structure, moving the negative electrode structure to the impregnation section, and impregnating the negative electrode structure with the pre-lithiation solution; and pre-lithiating the negative electrode structure by moving the same from the impregnation section to the pre-lithiation section. The pre-lithiation is carried out by alternately electrochemically charging the first negative electrode active material layer and the second negative electrode active material layer in the pre-lithiation section.

An electrochemical pretreatment method of a vanadium positive electrode for a lithium secondary battery, which can improve the lifetime characteristics of the positive electrode and the battery by inhibiting the leaching of vanadium when charging and discharging the lithium secondary battery using, for instance, vanadium oxide (V.sub.2O.sub.5) as a positive electrode, and a vanadium positive electrode for a lithium secondary battery pretreated thereby. The electrochemical pretreatment method of the vanadium positive electrode for a lithium secondary battery includes a) a step of discharging the lithium free vanadium positive electrode at a voltage of 1.9 V or more; b) an electrochemical pretreatment step of maintaining the discharged vanadium positive electrode of a) at an onset potential value or a potential value having a maximum current through a potentiostat; and c) a step of charging and discharging the pretreated vanadium positive electrode of b) at a voltage range of 2.1V to 4.0V.