Coated Lithium Reference Lead for Battery Cell Potential Monitoring

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium-ion batteries face challenges in characterizing non-equilibrium kinetics and thermodynamics within battery cells, leading to difficulties in measuring individual electrode potentials and tracking side reactions, which affects battery degradation, charging efficiency, and lifespan, especially in electric vehicles where rapid charging and long-term cycling are required.

Innovation Solution

A coated lithium reference lead is introduced, comprising a lithium metal strip coupled with a conductive wire and coated with a polymer, allowing for insertion into battery cells to provide real-time electrical measurements and improve mechanical robustness, enabling independent monitoring of anode and cathode potentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a reference electrode is placed in the battery cell to measure individual electrode potentials, then measurement precision is improved, but the reference electrode degrades rapidly due to contact with corrosive electrolyte

Engineering Contradiction:

Improveelectrode potential measurementVSAvoidreference electrode stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A polymer coating layer is introduced as an intermediary between the lithium metal reference electrode and the corrosive electrolyte. This coating allows ionic conduction while protecting the lithium metal from direct contact with the electrolyte, preventing degradation and maintaining measurement reliability over time.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin polymer film coating is applied to the lithium metal reference electrode. This flexible film provides mechanical protection and chemical isolation while maintaining ionic conductivity, enabling the reference electrode to function reliably in the corrosive battery environment.

Inventive Principle:

Principle #30Flexible shells and thin films

2Measurement precision

If lithium metal is used as reference electrode for accurate measurements, then measurement precision is improved, but mechanical robustness deteriorates due to lithium's soft and reactive nature

Engineering Contradiction:

Improveelectrochemical potential referenceVSAvoidmechanical robustness

Core Design Contradiction:

Measurement precisionVSStrength

Solution Approach 1:

The reference electrode is constructed as a composite structure with lithium metal core providing electrochemical reference functionality and polymer coating providing mechanical strength and protection. This composite design combines the advantages of both materials while mitigating their individual weaknesses.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

A polymer film shell is applied to the lithium metal core, providing mechanical robustness and protection while maintaining the electrochemical properties needed for accurate reference potential measurements.

Inventive Principle:

Principle #30Flexible shells and thin films

3Device complexity

If conventional two-electrode cell construction is used, then device complexity is reduced, but the ability to characterize non-equilibrium kinetics and thermodynamics is limited

Engineering Contradiction:

Improvecell constructionVSAvoidnon-equilibrium kinetics characterization

Core Design Contradiction:

Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The battery cell is segmented into three independent electrical connections: anode, cathode, and reference electrode. This segmentation allows independent measurement of each electrode's potential relative to the reference, enabling detailed characterization of non-equilibrium kinetics and thermodynamics while maintaining relatively simple cell construction.

Inventive Principle:

Principle #1Segmentation

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

This solution enhances the ability to characterize battery performance, optimizes charging cycles, extends battery lifespan, and facilitates rapid charging, making lithium-ion batteries more competitive with traditional energy technologies by providing accurate, real-time diagnostic information to Battery Management Systems.

Implementation Method 1

The polymer may be a conductive polymer. The conductive polymer may be an ionically conductive polymer.

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS11302955B2Battery cell design with a coated lithium reference electrode

Publication Date: 2022.04.12 CHONGQING JINKANG POWERTRAIN NEW ENERGY CO LTD

AI summary

A battery cell providing a coated lithium reference lead includes at least one anode layer, at least one cathode layer, and a reference lead. The reference lead includes a conductive wire, a layer of lithium metal coupled to the conductive wire, and a polymer coating that covers the layer of lithium metal. The reference lead is inserted into the battery cell with the at least one anode layer and the at least one cathode layer.