Lithium-Ion Electrode Particle Alignment via Magnetic Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion battery electrodes with non-spherical particles face challenges in achieving high energy density and charge/discharge rate capability due to unfavorable electrode microstructure and alignment, leading to limitations in electronic and ionic conductivity, particularly in the direction perpendicular to the current collector.
Innovation Solution
The method involves aligning non-spherical conductive particles using paramagnetic nanoparticles and externally applied magnetic fields during electrode fabrication, ensuring their high mobility directions align with the predominant ion and electron transport in batteries, resulting in densely packed electrodes with reduced tortuosity and enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If non-spherical particles are used in electrodes, then energy density is improved, but electronic and ionic conductivity deteriorates due to unfavorable microstructure and alignment
Solution Approach 1:
The patent changes the alignment parameter of non-spherical particles from random or horizontal orientation to vertical orientation perpendicular to the current collector. This parameter change enables the particles to maintain their high energy density while achieving favorable electronic and ionic conductivity pathways through the electrode structure.
Solution Approach 2:
The patent creates a composite electrode structure where non-spherical particles are vertically aligned within a conductive matrix. This composite approach combines the high energy density of non-spherical particles with the conductivity benefits of a structured arrangement, resolving the contradiction between quantity and reliability.
2Quantity of substance
If non-spherical particles are used in electrodes, then energy density is improved, but charge/discharge rate capability deteriorates due to unfavorable alignment
Solution Approach 1:
The patent changes the spatial orientation parameter of non-spherical particles to vertical alignment, which creates direct pathways for ion and electron transport perpendicular to the current collector. This parameter change enables high charge/discharge rates while maintaining the high energy density provided by non-spherical particle morphology.
3Reliability
If spherical particles are used to improve conductivity, then electronic and ionic conductivity is improved, but energy density deteriorates
Solution Approach 1:
The patent creates a composite structure where non-spherical particles are vertically aligned within a conductive matrix. This composite approach combines the high energy density of non-spherical particles with the conductivity benefits of a structured arrangement, resolving the contradiction between quantity and reliability.
4Ease of manufacture
If graphite platelets align parallel to current collector during fabrication, then manufacturing is simplified, but ion and electron transport capability deteriorates in perpendicular direction
Solution Approach 1:
The patent changes the alignment parameter of graphite platelets from parallel to perpendicular orientation relative to the current collector. This parameter change maintains manufacturing feasibility while dramatically improving ion and electron transport capability in the perpendicular direction, which is critical for battery performance.
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 approach enables the fabrication of electrodes with higher energy density and charge/discharge rate capability, reducing tortuosity in specific directions, allowing for thicker electrodes with comparable rate-performance or the same thickness with increased rate-performance, while accommodating volume changes during lithiation/delithiation.
Implementation Method 1
aligning non-spherical conductive particles using paramagnetic nanoparticles and externally applied magnetic fields during electrode fabrication
Implementation Method 2
The method involves aligning non-spherical conductive particles using paramagnetic nanoparticles and externally applied magnetic fields
Data Source
AI summary
A method for the manufacturing of electrodes with at least one porous surfacial layer comprising anisotropic electrochemically active particles. It also relates to electrodes made using such a method. The method comprises the following steps: (a) coupling of paramagnetic nanoparticles to said active particles for the generation of composites; (b) preparation of a slurry of said composites, including a solvent mixed with a binder able to release a volatile component; (c) application of said slurry to a substrate to form a film; (d) application of a magnetic field to the film and orienting said active particles leading to a substrate in which said active particles are arranged with their shortest axes aligned along a preferred axis parallel to said substrate; (e) during or after application of said magnetic field evaporation of said solvent with solidification of the binder and release of said volatile component under formation of said surfacial layer.