Lithium-Ion Electrode Vertical Vents via Thermal Additive Decomposition
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Solution Overview
Problem
Current lithium-ion battery electrodes face inefficiencies in lithium-ion transmission under high-current conditions due to tortuous and porous structures, leading to lithium precipitation and increased risk of short circuits, and existing preparation methods are energy-intensive, time-consuming, and difficult to industrialize.
Innovation Solution
A method involving a thermal decomposition additive with specific proportion and particle size is used in the electrode slurry, controlled to decompose and form vertical vents after solvent evaporation, enhancing lithium-ion transmission efficiency through less-tortuous pathways.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional highly tortuous and porous electrode structures are used, then electrode thickness and compaction density can be increased for high-power output, but lithium-ion transmission efficiency deteriorates and lithium precipitation risk increases
Solution Approach 1:
The electrode structure is segmented into two distinct pore systems: vertical vents (tens of microns aperture) perpendicular to the electrode surface and disordered holes (1 nm to 10 um) within the electrode matrix. This segmentation creates dedicated fast transmission channels (vertical vents) separate from the active particle penetration paths (disordered holes), allowing high-current lithium-ion transmission without requiring highly tortuous structures throughout the entire electrode.
Solution Approach 2:
The invention introduces a vertical dimension (perpendicular to electrode surface) with aperture of approximately tens of microns, transforming the conventional two-dimensional porous structure into a three-dimensional structure with vertical vents. This dimensional change creates direct transmission pathways from the electrolyte through the electrode thickness, dramatically reducing transmission path length and improving lithium-ion transmission efficiency under high-current conditions.
2Reliability
If existing preparation methods for vertical vent structures are implemented, then lithium-ion transmission efficiency is improved, but energy consumption increases and process complexity increases
Solution Approach 1:
The thermal decomposition additive automatically decomposes during the existing drying process to form vertical vent structures, eliminating the need for separate vent-creation steps. The additive self-generates the vertical vents through thermal decomposition, and the slurry itself fills the vents during drying, making the entire process self-contained and compatible with conventional manufacturing without additional equipment or steps.
Solution Approach 2:
The invention changes the chemical composition parameter of the slurry by adding thermal decomposition additives (ammonium bicarbonate, urea, or sodium bicarbonate) with specific decomposition temperatures. This parameter change enables the slurry to autonomously form vertical vents during drying through controlled decomposition, transforming a structurally complex electrode into one with vertical vents using only compositional modification and existing drying parameters.
3Manufacturing precision
If thermal decomposition additive decomposes before solvent evaporation completes, then vertical vents form early, but electrode slurry flows autonomously and fills the vents, reducing transmission efficiency
Solution Approach 1:
The invention establishes a feedback relationship between solvent evaporation and additive decomposition through temperature control. The decomposition temperature of the additive is selected to be higher than the initial drying temperature but lower than the final drying temperature, creating a feedback mechanism where solvent evaporation progress controls additive decomposition timing. This ensures vertical vents form only after the slurry loses流动性 and can no longer fill the vents, maintaining transmission efficiency.
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 method results in a lithium-ion battery electrode sheet with uniformly distributed vertical vents, improving ion transmission efficiency while being simple, cost-effective, and compatible with industrial processes, enabling large-scale manufacturing.
Implementation Method 1
a thermal decomposition additive with a specific proportion content and a specified particle size is used as a composition of an electrode slurry. Further, an evaporation rate of a solvent and a decomposition rate of the thermal decomposition additive are required to be controlled such that the thermal decomposition additive may be completely decomposed and consumed after the solvent is completely evaporated.
Implementation Method 2
an evaporation rate of a solvent and a decomposition rate of the thermal decomposition additive are required to be controlled such that the thermal decomposition additive may be completely decomposed and consumed after the solvent is completely evaporated
Data Source
AI summary
A preparation method of a lithium-ion battery electrode sheet includes: adding a powdered thermal decomposition additive, an active material, a binder, and a conductive agent into a solvent according to a predetermined ratio and a specific order, performing continuous stirring until the solvent is uniformly mixed, obtaining an electrode slurry, coating the prepared and obtained electrode slurry onto a current collector to obtain a lithium-ion battery wet electrode sheet, and heating and drying the lithium-ion battery wet electrode sheet. The lithium-ion battery electrode sheet with the vertical vent structures is accordingly prepared and obtained. The product includes a current collector, an electrode coating layer, and a plurality of vertical vent structures which are uniformly distributed.