Sodium-Ion Battery Anode Using Novel Precursor Compounds

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Sodium-ion batteries face challenges with negative electrodes due to the large ionic radius of sodium, leading to poor insertion properties in graphite and the use of toxic, non-renewable materials like antimony and tin, which result in reduced energy density and cycling stability.

Innovation Solution

The use of novel precursor compounds of sodium alloys, specifically formulated as MnE1xE2, where M is a transition metal and E1 and E2 are elements like In, Bi, Ge, Sn, and P, which are less toxic and potentially recyclable, as anode active materials in sodium-ion batteries, allowing for excellent electrochemical performance and reduced volume expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If graphite is used as negative electrode material, then cost is reduced and safety is improved, but sodium insertion properties deteriorate due to large ionic radius

Engineering Contradiction:

ImprovecostVSAvoidsodium insertion properties

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the negative electrode material by incorporating elements like Si, Ge, Sn, Pb, In, Ga, Al, or their alloys, transforming graphite from a poor sodium insertion material into an effective negative electrode that accommodates sodium's large ionic radius through alloying mechanisms

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates composite negative electrode materials combining graphite with alloying elements (Si, Ge, Sn, Pb, In, Ga, Al) to achieve both low cost and good sodium insertion properties, leveraging the advantages of both graphite (low cost, safety) and alloy materials (good sodium insertion)

Inventive Principle:

Principle #40Composite materials

2Reliability

If antimony or tin is used as negative electrode active material, then electrochemical performance is improved, but toxicity increases and resource sustainability deteriorates

Engineering Contradiction:

Improveelectrochemical performanceVSAvoidtoxicity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention modifies the composition parameters by introducing alternative elements (Si, Ge, In, Ga, Al) and their combinations to replace or reduce the content of toxic elements (Sb, Sn), maintaining electrochemical performance while reducing toxicity and improving resource sustainability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention employs abundant, non-toxic, and potentially recyclable elements (Si, Ge, In, Ga, Al) that are more sustainable than depleting resources like antimony and tin, ensuring long-term viability of sodium-ion batteries

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If hard carbon is used as anode active material, then sodium ion absorption is improved, but energy density decreases due to passivation layer formation

Engineering Contradiction:

Improvesodium ion absorptionVSAvoidenergy density

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention changes the surface and bulk properties of the negative electrode material through alloying elements that modify the electrochemical behavior, reducing the formation of passivation layers while maintaining good sodium ion absorption capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention converts the harmful passivation effect into a beneficial surface modification by controlled alloying, where the alloying elements create a stable surface composition that prevents excessive passivation while maintaining ion transport pathways

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

These compounds achieve high initial specific capacity and cycling stability, equivalent to or better than lithium-ion batteries, while avoiding electrolyte degradation and reducing the use of toxic elements, with improved electron conduction and volume expansion management.

Implementation Method 1

a compound capable of inserting sodium ions reversibly

Methodology Applied

Scientific EffectIon insertion/extraction: Absorption (physical)

Implementation Method 2

improved electron conduction

Methodology Applied

Scientific EffectElectron conduction: Conduction (electrical)

Data Source

PatentUS10326130B2Use of novel compounds as negative electrode active material in a sodium-ion battery

Publication Date: 2019.06.18 CENT NAT DE LA RECH SCI (C N R S)

AI summary

Precursor compounds of sodium alloy(s), for use as negative electrode active material in a sodium-ion battery, as well as to a negative electrode have the precursor compound of sodium alloy(s), as well as a sodium-ion battery having a negative electrode of this kind.