Method for checking dispersion of electrode material layer

Abstract

The present invention relates to a method for checking the dispersion of an electrode material layer of an electrode for a lithium rechargeable battery, the electrode having the electrode material layer, comprising an active material, a conductive material and a binder, formed on at least one surface of an electrode current collector, and the method for checking the dispersion of the electrode material layer comprising the steps of: (a) selecting two arbitrary points (1-1') of the electrode material layer; (b) measuring a voltage between the two points (1-1') for each of mutually different current directions, and calculating the difference (delta 1) between the absolute values of the two voltage values; (c) selecting two arbitrary points (2-2' to n-n'; n is an integer equal to or greater than 2) which are different from the two points selected in step (a), and calculating delta 2 to delta n by repeating steps (a) and (b) one or more times; (d) calculating the average of the differencesbetween the absolute values, delta 1 to delta n, obtained by repeating steps (b) and (c); and (e) calculating the standard deviation of delta 1 to delta n from the average, wherein the dispersion ofthe electrode material layer is determined to increase as the standard deviation value of step (e) decreases.

Description

technical field [0001] Cross References to Related Applications [0002] This application claims priority to Korean Patent Application No. 10-2018-0131267 filed with the Korean Intellectual Property Office on October 30, 2018, the disclosure of which is hereby incorporated by reference in its entirety. [0003] The present invention relates to a method for inspecting the dispersibility of an electrode material layer, in particular, to a method for inspecting the dispersibility of an electrode material layer by measuring the voltage of the electrode material layer. Background technique [0004] With the development of technology and the increase in the demand for mobile devices, the demand for secondary batteries as energy sources has increased dramatically, and among secondary batteries, Li-II batteries with high energy density and operating potential, long cycle life and low self-discharge rate Secondary batteries are being commercialized and widely used. [0005] In add...

AI Technical Summary

Problems solved by technology

Among them, in particular, when the dispersibility of the conductive material is poor, the deviation of the electronic conductivity of the electrode increases, which affects the overall performance of the lithium secondary battery such as output characteristics, rate characteristics, and life characteristics due to reasons such as an increase in resistance

[0009] Therefore, electrodes with very poor dispersion are defective and actually cause various problems as the battery is used, but there is no way to determine the dispersion with a non-destructive scheme, so it is impossible to find out the cause of the dispersion of the electrode Defects and constant complaints from users

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