Secondary battery cathode and lithium secondary battery comprising same

一种二次电池、正极集电体的技术,应用在二次电池、二次电池维修/保养、电池电极等方向,能够解决无法充分确保电池稳定性等问题,达到改善稳定性的效果

Active Publication Date: 2019-07-30
LG ENERGY SOLUTION LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] However, this method is only used to periodically check the status of the battery, and may not sufficiently ensure the stability of the battery

Method used

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  • Secondary battery cathode and lithium secondary battery comprising same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0092] 50 parts by weight of LiFePO 4 positive electrode active material, 3 parts by weight of carbon black as a conductive agent, 3 parts by weight of polyvinylidene fluoride (PVdF) as a binder, and 44 parts by weight of Li as a gas generating agent 2 CO 3 mixed in N-methylpyrrolidone (NMP) solvent to prepare a first cathode active material slurry.

[0093] Additionally, 94 parts by weight of LiNi 0.6 mn 0.2 co 0.2 o 2 A positive active material, 3 parts by weight of carbon black as a conductive agent, and 3 parts by weight of PVdF as a binder were mixed in an NMP solvent to prepare a second positive active material slurry.

[0094] A 20 μm thick Al foil was coated with the first positive electrode active material slurry prepared above, and then dried to form a 10 μm thick first positive electrode active material layer. Subsequently, the second positive electrode active material slurry was coated on the first positive electrode active material layer, dried, and then rol...

Embodiment 2

[0098] In the same manner as in Example 1, a positive electrode and a lithium secondary battery containing it were prepared, except that 20 parts by weight of LiFePO 4 positive electrode active material, 3 parts by weight of carbon black as a conductive agent, 3 parts by weight of polyvinylidene fluoride (PVdF) as a binder, and 74 parts by weight of Li as a gas generating agent 2 CO 3 To prepare the first cathode active material slurry.

experiment example 1

[0108] Experimental Example 1: Overcharge Test

[0109] The overcharge test was performed by using the secondary batteries prepared in Examples 1 and 2 and Comparative Examples 1 to 3. Specifically, after each secondary battery was charged at 0.3C to the full charge voltage (4.25V) and the charge was cut off at 0.05C, each secondary battery was subjected to a rest time of 3 hours to stabilize the voltage. After the battery voltage was stabilized, each secondary battery was overcharged at 1C to a voltage of 6.4V.

[0110] In this regard, figure 1 is a graph showing overcharge tests of lithium secondary batteries prepared in Examples 1 and 2 and Comparative Examples 1 to 3 of the present invention.

[0111] For the lithium secondary batteries of Examples 1 and 2, it was confirmed that the voltage rapidly increased due to overcharging occurring above 4.8 V, and therefore, it was considered that the overcharging cut-off voltage was reached quickly.

[0112] For Comparative Exam...

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PUM

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Abstract

The present invention relates to a secondary battery cathode for improving stability upon overcharging and a lithium secondary battery comprising the same and, specifically, to a secondary battery cathode and a lithium secondary battery comprising the same, the secondary battery cathode being a cathode comprising a cathode active material formed on a cathode current collector, wherein the cathodeactive material has a two-layer structure including a first cathode active material layer formed on the cathode current collector and a second cathode active material layer formed on the first cathodeactive material layer, the first cathode active material layer includes a first cathode active material, a conductive material, and a gas generating material for generating gas upon overcharging, andthe second cathode active material layer includes a second cathode active material.

Description

technical field [0001] Cross References to Related Applications [0002] This application claims the benefit of Korean Patent Application No. 2017-0096435 filed with the Korean Intellectual Property Office on July 28, 2017, the disclosure of which is hereby incorporated by reference in its entirety. technical field [0003] The present invention relates to a positive electrode for a secondary battery and a lithium secondary battery including the same. Background technique [0004] With the technological development and increase in demand for mobile devices, the demand for secondary batteries as energy sources has significantly increased, and among these secondary batteries, high energy density, high operating voltage, long cycle life and low self-discharge rate Lithium secondary batteries have been commercialized and widely used. [0005] Recently, with the use of lithium secondary batteries as power sources for medium and large devices such as electric vehicles, the d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/13H01M10/42H01M4/62H01M4/58H01M4/525H01M4/505H01M4/485H01M10/052
CPCH01M4/505H01M4/525H01M4/62H01M4/131H01M4/136H01M4/366H01M4/5825H01M10/0525Y02E60/10H01M4/13H01M10/4235H01M4/485H01M10/052H01M4/5805H01M4/625H01M2004/021H01M2004/028H01M4/58H01M10/42
Inventor 李京珉崔正锡金京旼吴松泽
Owner LG ENERGY SOLUTION LTD
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