Sulfonate-Coated Cathode Material for Durable Low-Resistance Batteries

Solution Overview

Problem

Existing lithium-containing composite oxides in the form of single particles exhibit poor durability and high direct current resistance, with existing technologies not addressing the compatibility between these two factors effectively.

Innovation Solution

A positive electrode active material is developed by coating lithium-containing composite oxide particles with a sulfonate compound, which are composed of single particles with specific size and composition, and incorporating a method that includes synthesis, washing, drying, and addition of the sulfonate compound to enhance durability and reduce direct current resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lithium-containing composite oxides are formed as single particles to improve durability, then durability is improved, but direct current resistance increases

Engineering Contradiction:

ImprovedurabilityVSAvoiddirect current resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by coating only the surface of the lithium-containing composite oxide particles with a sulfonate compound. This creates a differentiated structure where the core maintains its single-particle morphology for durability, while the surface layer provides low resistance. The sulfonate compound forms a thin film specifically on the particle surface, addressing the resistance issue locally without compromising the overall single-particle structure that provides durability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates a composite material system consisting of the lithium-containing composite oxide core and the sulfonate compound coating. This composite structure combines the advantages of both components: the single-particle lithium-containing composite oxide provides durability and structural stability, while the sulfonate compound layer provides low direct current resistance and improved electrochemical performance. The combination resolves the contradiction between durability and resistance.

Inventive Principle:

Principle #40Composite materials

2Reliability

If single particles are used to improve durability, then durability is improved, but both suppression of direct current resistance and durability cannot be achieved simultaneously

Engineering Contradiction:

ImprovedurabilityVSAvoidcompatibility between suppression of direct current resistance and durability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by coating only the surface of the lithium-containing composite oxide particles with a sulfonate compound. This creates a differentiated structure where the core maintains its single-particle morphology for durability, while the surface layer provides low resistance. The sulfonate compound forms a thin film specifically on the particle surface, addressing the resistance issue locally without compromising the overall single-particle structure that provides durability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates a composite material system consisting of the lithium-containing composite oxide core and the sulfonate compound coating. This composite structure combines the advantages of both components: the single-particle lithium-containing composite oxide provides durability and structural stability, while the sulfonate compound layer provides low direct current resistance and improved electrochemical performance. The combination resolves the contradiction between durability and resistance.

Inventive Principle:

Principle #40Composite materials

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 coated lithium-containing composite oxide particles achieve high durability and suppressed direct current resistance, leading to improved battery performance and capacity.

Implementation Method 1

a sulfonate compound present on a surface of the lithium-containing composite oxide

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentEP4704189A1Positive electrode active material for nonaqueous electrolyte secondary batteries, nonaqueous electrolyte secondary battery, and method for producing positive electrode active material for nonaqueous electrolyte secondary batteries

Publication Date: 2026.03.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

Figure 1

AI summary

The present invention provides a positive electrode active material which has high durability and enables a battery to have a reduced DC resistance. A positive electrode active material for nonaqueous electrolyte secondary batteries according to one embodiment of the present disclosure is characterized by containing a lithium-containing composite oxide and a sulfonic acid compound that is present on the surface of the lithium-containing composite oxide. This positive electrode active material is also characterized in that: the lithium-containing composite oxide is composed of isolated particles having an average particle diameter of 0.5 µm to 5 µm inclusive, and contains 70 mol% or more of Ni and Mn in total with respect to the total molar quantity of metal elements excluding Li; and the sulfonic acid compound is represented by general formula I. In the formula, A represents a group 1 element or a group 2 element; R represents a hydrocarbon group; and n is 1 or 2.