Nickel Oxide Cathode Composition for Lower DC Resistance

Solution Overview

Problem

Existing non-aqueous electrolyte secondary batteries face challenges in reducing direct current resistance, particularly due to the high interfacial transfer resistance associated with larger average particle diameters of positive electrode active materials.

Innovation Solution

A positive electrode active material comprising a mixture of first lithium nickel oxide particles with an average diameter of 8 to 30 µm and second lithium nickel oxide particles with an average diameter of up to 6 µm, with a higher concentration of sulfonate compounds on the surfaces of the larger particles, reducing interfacial transfer resistance without compromising electrical conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the average particle diameter of the positive electrode active material is increased, then the specific surface area is reduced, but the interfacial transfer resistance increases

Engineering Contradiction:

Improvespecific surface areaVSAvoidinterfacial transfer resistance

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The positive electrode active material is segmented into two distinct particle size ranges: first lithium nickel oxide particles with an average particle diameter of 8 µm to 30 µm, and second lithium nickel oxide particles with an average particle diameter of 3 µm to 6 µm. This segmentation allows the larger particles to provide high capacity while the smaller particles provide high surface area, collectively reducing interfacial transfer resistance without sacrificing specific surface area

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the particle size distribution are assigned different functions: larger particles (8-30 µm) serve as the primary capacity storage, while smaller particles (3-6 µm) are specifically designed to reduce interfacial transfer resistance. This local quality differentiation resolves the contradiction by optimizing each particle size range for its specific function

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the average particle diameter of the positive electrode active material is increased, then the capacity is improved, but the direct current resistance increases

Engineering Contradiction:

Improvebattery capacityVSAvoiddirect current resistance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The positive electrode active material is segmented into two distinct particle size ranges: first lithium nickel oxide particles with an average particle diameter of 8 µm to 30 µm, and second lithium nickel oxide particles with an average particle diameter of 3 µm to 6 µm. This segmentation allows the larger particles to provide high capacity while the smaller particles provide high surface area, collectively reducing interfacial transfer resistance without sacrificing specific surface area

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention creates a composite particle system combining two different lithium nickel oxide particle sizes with distinct functional characteristics. The composite structure integrates the high capacity advantage of large particles with the low resistance advantage of small particles, achieving both high capacity and low direct current resistance simultaneously

Inventive Principle:

Principle #40Composite materials

Data Source

PatentEP4704187A1Positive electrode active material for non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary battery

Publication Date: 2026.03.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

Figure 1

AI summary

A positive electrode active material comprises first lithium nickel oxide particles ( average particle size: 8-30 µm) and second lithium nickel oxide particles (≤ 6 µm). A sulfonic acid compound of general formula I (where A is a group 1 or 2 element, R is a hydrocarbon group, and n is 1 or 2) exists on the surface of the first particles. When X and Y are defined as the mass ratios of the sulfonic acid compound to the respective particle masses, the relation X≥Y is satisfied.