A separator for a lithium secondary battery comprising a porous polymer substrate and a porous coating layer on at least one surface of the porous polymer substrate. The separator has an ionic conductivity of 4.75×10.sup.−5 S/cm or more, and the porous coating layer comprises an interstitial volume and a macro pore having a larger diameter than the interstitial volume. A method for manufacturing the separator is also disclosed. Accordingly, the separator has significantly improved ionic conductivity over commercial separators.

A nonaqueous electrolyte energy storage device according to one aspect of the present invention is a nonaqueous electrolyte energy storage device including a positive electrode having positive active material particles, in which the positive active material particles contain a lithium transition metal composite oxide having an α-NaFeO.sub.2 structure, the lithium transition metal composite oxide contains at least one of nickel and cobalt, and manganese, a content of lithium with respect to a transition metal in the lithium transition metal composite oxide exceeds 1.0 in terms of a molar ratio, a diffraction peak is present in a range of 20° or more and 22° or less in an X-ray diffraction diagram of the lithium transition metal composite oxide using a CuKα ray, and the positive active material particles contain aluminum.

Discussed is a battery system including a battery; a first main relay connected between one electrode and a first output terminal of the battery; a pre-charge relay connected to the first main relay in parallel; a second main relay connected between another electrode and a second output terminal of the battery; and a battery management system controlling charging and discharging of the battery, and controlling the first main relay, the pre-charge relay, and the second main relay, wherein the battery management system opens the first main relay, the pre-charge relay, and the second main relay when a received power voltage is a predetermined reference voltage or less, closes the pre-charge relay and the second main relay to execute a pre-charge when the power voltage is higher than the reference voltage, and closes the first main relay after the pre-charge is completed.

A device for charging and discharging a battery cell capable of suppressing a swelling phenomenon of a terrace portion of a battery cell during a formation process of the battery cell includes first and second plates configured to receive a battery cell therebetween and to press two surfaces of the battery cell; first and second grippers connected to the first and second plates, respectively, the first and second grippers protrude to face each other and configured to contact a lead region of the battery cell; and first and second pressing pads positioned inward of the first and second grippers, the first and second pressing pads being configured to contact a terrace region of the battery cell. A method of charging and discharging a battery cell using the same is also provided.

The non-aqueous electrolyte secondary cell according to the present invention comprises: an electrode body constituted by a positive electrode including a positive electrode active material comprising a lithium-containing transition metal oxide, a negative electrode including a negative electrode current collector onto which metallic lithium is deposited during charging, and a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte. The molar ratio of the total lithium content of the positive electrode and the negative electrode to the transition metal content of the positive electrode is 1.1 or less. During discharging, the positive electrode capacitance α(mAh) of the positive electrode and the volume X (mm.sup.3) of a hollow constituted by a space formed in the center of the electrode body 14 satisfy the relationship 0.5≤X/α≤4.0.

According to one embodiment, a method of producing a secondary battery includes preparing a battery architecture, which includes a positive electrode, a negative electrode, and an electrolyte, providing a potential adjusted state by adjusting a positive electrode potential to 4.3 V to 4.8 V and a negative electrode potential to 0.5 V to 1.1 V based on oxidation-reduction potential of lithium, and holding the battery architecture in the potential adjusted state. The positive electrode includes a nickel-containing oxide represented by a general formula Li.sub.xM1O.sub.2. M1 is a metal element including at least Ni in an elemental ratio of 50% or more, and 0<x≤1. The negative electrode includes a titanium-containing oxide. The electrolyte includes a sulfur-containing compound.

The present invention relates to a method for manufacturing a secondary battery and a secondary battery. The method for manufacturing the secondary battery comprises an accommodation step of accommodating an electrode assembly in an accommodation part of a battery case, a vent membrane mounting step of mounting a vent membrane on a discharge hole, which passes between the inside and outside of the battery case, in the battery case, and a case sealing step of sealing the battery case, wherein the vent membrane allows only a gas to pass through the discharge hole of the battery case, but blocks a liquid.

In a method for inspecting the insulation property of a secondary battery by connecting an external DC power supply to the secondary battery charged with an initial charge amount and evaluating the insulation property of the secondary battery based on a converging state of a power-supply current, when a charge amount at which an inclination of a tangent to a charge amount—battery voltage curve representing a relationship between the charge amount and a battery voltage of the secondary battery is smallest is assumed as a minimum-inclination charge amount, and the inclination of the tangent at the minimum-inclination charge amount is assumed as a minimum inclination (αL), the initial charge amount is selected from a range of the charge amount in which the inclination is two or more times the minimum inclination.

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 charging and discharging device including a plurality of pressing plates and at least one spacer for supporting a gas pocket of a battery cell to prevent gas pocket interference between battery cells and increase the space utilization rate of the gas pocket during the formation process of the battery cell.