Lg Energy Solution, Ltd.

Lg Chem, Ltd

Kwang Ho Yoo

Hyun Woo Park

Dong Hui Kim

Young Joon Shin

Sa Rah Kim

Dong Jun Lee

Han Ho Lee

Sang-Kyu Choi

Shulkee Kim

Wonhee Jung

Kyutae Park

Cheoljin Oh

Gayoung Lim

A negative electrode for a secondary battery includes a current collector and a negative electrode active material layer provided on at least one surface of the current collector. The negative electrode active material layer includes a first region corresponding to 50% of a total thickness of the negative electrode active material layer from a surface facing the current collector and a second region corresponding to 50% of the total thickness of the negative electrode active material layer from a surface opposite to the surface facing the current collector. The negative electrode active material layer includes two or more types of negative electrode active materials having D50 different from each other and satisfies the Equations 1 and 2. A secondary battery including the negative electrode is also provided.

Negative electrode and lithium secondary battery

A method of preparing a secondary battery including pre-lithiating an electrode assembly including an electrode structure including a plurality of electrodes and a plurality of separators, and a metal substrate. The plurality of electrodes and the plurality of separators are alternatingly stacked. The pre-lithiating includes supplying lithium ions from one of the plurality of positive electrodes to one of the plurality of negative electrodes up to a state of charge (SOC) of A % by electrically connecting one of the plurality of positive electrodes and one of the plurality of negative electrodes and applying a first current, supplying lithium ions from the metal substrate to the positive electrodes up to B % of capacity of the positive electrodes by electrically connecting the metal substrate and the positive electrodes and applying a second current, after applying the first current, and resting the electrode assembly, after applying the second current.

Method of preparing secondary battery

A method of preparing a secondary battery which includes pre-lithiating an electrode assembly which includes an electrode structure including a plurality of electrodes and a plurality of separators, and a metal substrate. The plurality of electrodes and the plurality of separators are alternatingly stacked. The metal substrate is present on an outermost surface of the electrode structure in a direction in which the electrode and the separator are stacked. Each positive electrode and negative electrode are spaced apart from each other with one separator of the plurality of separators disposed therebetween. The pre-lithiating includes applying a first current by electrically connecting one of the plurality of positive electrodes and one of the plurality of negative electrodes, and applying a second current by electrically connecting the metal substrate and one of the plurality of positive electrodes, after applying the first current.

A method for manufacturing a lithium ion polymer battery is provided in which in injecting electrolyte into a lithium ion polymer battery, the battery cell is immersed in an electrolyte impregnation bath to allow the electrolyte to be impregnated into the cell. The electrolyte can be impregnated simultaneously, and as the battery cell is activated, the electrolyte is settled down in the interior of the battery cell. Thus, when the battery cell is sealed, a phenomenon that the electrolyte is present at the sealed portion can be prevented.

Method for manufacturing lithium ion polymer battery, battery cell, and lithium ion polymer battery including the same

Provided is a pouch-type secondary battery including an electrode assembly, electrode tabs extending outward from the electrode assembly, a pouch-type battery case for housing the electrode assembly, first sealing portions for sealing the pouch-type battery case and the electrode tabs, and second sealing portions formed at positions with the exception of electrode tab-positioned sites between the first sealing portions and the electrode assembly. The secondary battery is configured to have a structure such that a channel is formed with electrode tab portions by further sealing inside portions of the electrode tabs with the exception of electrode tab-occupied portions. Such a structure allows for easy unidirectional discharge of gases even when the battery inside reaches a certain level of internal pressure due to evolution of gases and enables previous expectation of the gas discharge direction. Therefore, it is possible to provide a secondary battery with improved safety.

Growing community of inventors

Daejeon, South Korea

Kwang Ho Yoo