Iodine-Boron Cathode Coating for Low-Resistance Li-Ion Batteries

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Solution Overview

Problem

Lithium-ion secondary batteries face challenges in balancing high capacity characteristics with electrode resistance characteristics, particularly in nickel-rich positive electrode materials where coating films can increase resistance and degrade discharge capacity or cycle characteristics.

Innovation Solution

A positive electrode active material is developed with a core containing lithium transition metal oxide, coated with a layer of iodine and boron, which is formed by mixing lithium transition metal oxide, iodine, and boron and firing the mixture at a temperature of 150-500°C, resulting in improved electrode resistance and capacity characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a coating film based on boron ingredient is formed on the surface of electrode active material, then capacity characteristics are improved, but electrode resistance characteristics deteriorate

Engineering Contradiction:

Improvecapacity characteristicsVSAvoidelectrode resistance characteristics

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies composite materials by forming a coating film containing both boron and iodine on the lithium transition metal oxide surface. This composite coating combines the capacity-enhancing effect of boron with the resistance-reducing effect of iodine, resolving the contradiction between improved capacity and increased resistance that occurs with boron-only coatings

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the compositional parameters of the coating film by introducing iodine alongside boron. This parameter change transforms the coating from a single-element boron film to a dual-element boron-iodine film, which modifies the electrical properties to reduce resistance while preserving capacity benefits

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively enhances both capacity and resistance characteristics of lithium-ion secondary batteries, inhibiting the increase in electrode resistance and maintaining stable long-term cycle performance.

Implementation Method 1

a coating portion at least partially covering the surface of the core and containing iodine and boron... formed by mixing lithium transition metal oxide, iodine, and boron and firing the mixture at a temperature of 150-500°C

Methodology Applied

Scientific EffectThermal deposition: Deposition (physical)

Data Source

PatentUS20240162422A1Positive Electrode Active Material, Positive Electrode Active Material Slurry, Positive Electrode, Lithium-Ion Secondary Battery and Method for Preparing Positive Electrode Active Material

Publication Date: 2024.05.16 LG ENERGY SOLUTION LTD

AI summary

Provided are a positive electrode active material for a lithium-ion secondary battery having excellent capacity characteristics and electrode resistance characteristics, a positive electrode active material slurry, a positive electrode, a lithium-ion secondary battery and a method for preparing a positive electrode active material. The positive electrode active material includes a core containing a lithium transition metal oxide, and a coating portion at least partially covering the surface of the core and containing iodine and boron.