Composite Cathode Material Enhances Rate Capability

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Solution Overview

Problem

Electrochemical cells with carbon monofluoride cathodes have low rate capability, making them unsuitable for applications requiring high discharge rates, while liquid lithium-oxyhalide cathodes are caustic and volatile, posing safety risks in harsh environments.

Innovation Solution

A composite cathode material combining metallic phosphates with carbon monofluoride, increasing the rate capability of lithium electrochemical cells and providing a stable, non-volatile alternative for harsh environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If carbon monofluoride cathode material is used, then energy density is improved, but rate capability deteriorates

Engineering Contradiction:
Improveenergy densityVSAvoidrate capability
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent applies composite materials by combining carbon monofluoride (CFx) with metallic phosphate particles to create a composite cathode material. This composite structure allows the CFx to provide high energy density while the metallic phosphate particles provide pathways for improved ion and electron transport, thereby enhancing rate capability without sacrificing the high energy density of the original CFx material.

Inventive Principle:
Principle #40Composite materials

2Productivity

If liquid lithium-oxyhalide cathode material is used, then rate capability is improved, but safety deteriorates

Engineering Contradiction:
Improverate capabilityVSAvoidsafety
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the liquid lithium-oxyhalide cathode material with a solid composite cathode material comprising carbon monofluoride and metallic phosphate. This substitution eliminates the safety issues associated with liquid cathodes (causticity and volatility) while maintaining acceptable rate capability through the composite structure. The solid composite material is inherently safer and more stable in harsh environments.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Quantity of substance

If carbon monofluoride cathode is used, then discharge capacity is improved, but operational speed deteriorates

Engineering Contradiction:
Improvedischarge capacityVSAvoidoperational speed
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent applies local quality by distributing metallic phosphate particles throughout the carbon monofluoride cathode material. This creates localized regions of enhanced conductivity and ion transport within the composite structure. The metallic phosphate particles act as conductive networks that locally improve electron and ion transfer rates, thereby increasing overall operational speed while preserving the high discharge capacity of the CFx material.

Inventive Principle:
Principle #3Local quality

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 composite cathode material enhances the rate capability and stability of lithium electrochemical cells, enabling them to deliver high discharge capacity and operate safely in harsh conditions, such as petroleum exploration environments.

Implementation Method 1

electrochemical cells comprising an anode of a Group IA metal and a cathode of a composite material prepared from a combination of metal salts

Methodology Applied
Scientific EffectElectrochemical reaction:

Implementation Method 2

The composite cathode material enhances the rate capability and stability of lithium electrochemical cells, enabling them to deliver high discharge capacity

Methodology Applied
Scientific EffectIon diffusion: Diffusion

Data Source

PatentUS10109846B2Mixed cathode material with high energy density
Publication Date: 2018.10.23 ELECTROCHEM SOLUTIONS

AI summary

The present invention relates to an electrochemical cell comprising an anode of a Group IA metal and a cathode of a composite material prepared from a first active cathode material of a transition metal phosphate mixed or added to a second active cathode material of a carbonaceous material. The cathode material of the present invention provides increased rate pulse performance compared to carbon monofluoride cathode material. In addition, the cathode material of the present invention is chemically stable which makes it particularly useful for applications that require increased rate capability in extreme environmental conditions such as those found in oil and gas exploration.