Fluoride Ion Electrochemical Cell Eliminating Metallic Lithium

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Solution Overview

Problem

Conventional lithium-based electrochemical cells face limitations in achieving high specific energies, safety, and stability due to the use of metallic lithium, which results in restricted operating voltages and potential safety risks.

Innovation Solution

The development of secondary anionic electrochemical cells using anion charge carriers and anion host materials eliminates the need for metallic lithium, enabling higher cell voltages, specific energies, and improved safety through the use of fluoride ion charge carriers and advanced electrode materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If metallic lithium is used in electrochemical cells, then high specific capacity is achieved, but safety risks and stability deteriorate due to reactive nature and non-epitaxial deposition

Engineering Contradiction:
Improvespecific capacityVSAvoidsafety and stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces an intercalation host material as an intermediary between metallic lithium and the electrolyte. This host material accommodates lithium ions through intercalation reactions, preventing direct contact between lithium metal and electrolyte, thereby eliminating safety risks while preserving high specific capacity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical system of metallic lithium deposition with a chemical intercalation system. Instead of lithium metal directly depositing on the electrode, lithium ions are inserted into the host material structure through intercalation reactions, providing epitaxial growth and improved stability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If conventional lithium-based electrochemical cells are used, then compatibility with existing technology is maintained, but operating voltage and specific energy are restricted

Engineering Contradiction:
Improvetechnology compatibilityVSAvoidoperating voltage and specific energy
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The patent changes the electrochemical parameters of the system by using intercalation host materials with different redox potentials. This allows operating voltages to exceed the conventional 3.8V limit while maintaining compatibility with existing battery architectures and manufacturing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite electrode structures combining intercalation host materials with conductive additives and binders. These composite materials enable higher operating voltages and specific energies while maintaining structural integrity and compatibility with existing battery designs

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If lithium metal is used for high energy density, then specific energy is improved, but device complexity and safety systems increase due to reactive handling requirements

Engineering Contradiction:
Improvespecific energyVSAvoidsafety systems and handling requirements
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The intercalation host material serves as a protective intermediary that eliminates the need for complex safety systems. By preventing direct exposure of lithium metal to electrolyte and atmosphere, the host material simplifies device design and handling requirements while maintaining high specific energy

Inventive Principle:
Principle #24Intermediary (Mediator)

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 proposed electrochemical cells achieve higher specific energies, longer cycle life, and enhanced safety compared to conventional lithium-ion batteries, with fluoride ion cells exhibiting voltages greater than 3.5 V and cycle life exceeding 500 cycles.

Implementation Method 1

an electrolyte provided between the positive electrode and the negative electrode, wherein the electrolyte is capable of conducting anion charge carriers

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

the positive electrode and negative electrode are capable of reversibly exchanging the anion charge carriers with the electrolyte during charging or discharging of the electrochemical cell

Methodology Applied
Scientific EffectIntercalation: Absorption (physical)

Data Source

PatentEP1993953B1Fluoride ion electrochemical cell
Publication Date: 2018.09.05 CALIFORNIA INST OF TECH
  • EP1993953B1 patent drawingFigure 1A~1B
  • EP1993953B1 patent drawingFigure 2~3A
  • EP1993953B1 patent drawingFigure 3B

AI summary

The present invention provides electrochemical cells capable of good electronic performance, particularly high specific energies, useful discharge rate capabilities and good cycle life. Electrochemical cells of the present invention are versatile and include primary and secondary cells useful for a range of important applications including use in portable electronic devices. Electrochemical cells of the present invention also exhibit enhanced safety and stability relative to conventional state of the art primary lithium batteries and lithium ion secondary batteries. For example, electrochemical cells of the present invention include secondary electrochemical cells using anion charge carriers capable of accommodation by positive and negative electrodes comprising anion host materials, which entirely eliminate the need for metallic lithium or dissolved lithium ion in these systems.