Nickel Oxide Cathode Coating and Electrolyte for Low DC Resistance

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Solution Overview

Problem

Nonaqueous electrolyte secondary batteries using nickel-based composite oxides face increased DC resistance due to repeated charging and discharging, which degrades output characteristics.

Innovation Solution

Incorporating a tungsten compound on the surface of nickel-based composite oxide particles and using an unsaturated sultone compound and methyl acetate in the nonaqueous electrolyte to form a protective film that reduces DC resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If nickel-based composite oxide is used as positive electrode active material, then battery capacity is improved, but DC resistance increases and output characteristics deteriorate

Engineering Contradiction:

Improvebattery capacityVSAvoidDC resistance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by coating only the surface of nickel-based composite oxide particles with tungsten compound, rather than changing the bulk composition. This surface modification locally alters the properties at the particle surface where electrochemical reactions occur, reducing DC resistance while preserving the high capacity of the nickel-based bulk material.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates a composite structure by combining nickel-based composite oxide with tungsten compound coating. This composite material approach allows the core nickel-based oxide to provide high capacity while the tungsten compound shell provides low resistance and stability, resolving the contradiction between capacity and resistance.

Inventive Principle:

Principle #40Composite materials

2Reliability

If tungsten compound is attached on the surface of nickel-based composite oxide particles, then initial DC resistance is reduced, but repeated charging and discharging increases DC resistance and reduces output characteristics

Engineering Contradiction:

Improveinitial DC resistanceVSAvoidoutput characteristics after repeated cycles

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by pre-coating the nickel-based composite oxide particles with tungsten compound before battery assembly. This preliminary surface treatment creates a protective layer that stabilizes the particle surface in advance, preventing degradation during subsequent charge-discharge cycles and maintaining low DC resistance throughout the battery lifecycle.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The tungsten compound coating acts as a cushioning layer that protects the nickel-based composite oxide particles from degradation during repeated charging and discharging. This beforehand protection prevents the increase in DC resistance and maintains output characteristics over time.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 significantly suppresses the increase in DC resistance, maintaining high capacity and excellent output characteristics over repeated charge and discharge cycles.

Implementation Method 1

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 2

a tungsten compound attached to a surface of the particles

Methodology Applied

Scientific EffectSurface attachment: Adsorption

Data Source

PatentEP4024507B1Non-aqueous electrolyte secondary battery

Publication Date: 2026.01.28 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

Figure 1

AI summary

A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes a positive electrode material including particles of a composite oxide containing lithium and a metal Me other than lithium, and a tungsten compound attached to a surface of the particles. The metal Me contains at least nickel. The nonaqueous electrolyte includes an unsaturated sultone compound.