Guide Roll Thermal Zoning for Stress-Reduced Electrode Calendering
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Solution Overview
Problem
Mechanical compaction of electrodes in battery cell production leads to deformations and stress buildup, which can hinder further processing and application of safety coatings.
Innovation Solution
A calendering apparatus with a guide roll having regions of different thermal conductivities and insulating depressions to control stress release through controlled thermal energy supply, reducing mechanical stress buildup and preventing deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high mechanical pressure is applied to the electrode during compaction to increase bulk density, then the energy density of the battery cell is improved, but mechanical stresses build up within the electrode causing deformations that hinder further processing
Solution Approach 1:
The patent applies thermal energy to the electrode before compaction, changing the temperature parameter to reduce mechanical stress buildup. The guide roll with different thermal conductivities (first region with higher thermal conductivity, second region with lower thermal conductivity) creates controlled thermal gradients that prevent stress-induced deformations while maintaining compaction effectiveness.
Solution Approach 2:
The patent performs preliminary heating of the electrode through the guide roll before the compaction process. This preliminary thermal treatment prepares the electrode material to better withstand mechanical compression, reducing the likelihood of deformation during the subsequent high-pressure compaction operation.
2Manufacturing precision
If thermal energy is supplied to the electrode prior to compaction to reduce stress buildup, then deformation is reduced, but thermal energy loss to the guide roll increases
Solution Approach 1:
The guide roll is designed with spatially varying thermal conductivity properties. The first region has higher thermal conductivity for effective heat transfer, while the second region has lower thermal conductivity to minimize thermal energy loss. This local differentiation allows the system to maintain thermal energy where needed while reducing unnecessary heat dissipation.
Solution Approach 2:
The guide roll surface is segmented into distinct regions with different thermal conductivities. This segmentation allows independent optimization of heat transfer in different zones, enabling controlled thermal management that balances stress reduction with energy conservation during the compaction process.
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 apparatus effectively reduces mechanical stress and deformation in electrodes, ensuring stable processing and coating application by dissipating stress through controlled thermal management.
Implementation Method 1
the guide roll has first regions and second regions in sections on its rolling surface, wherein the first and the second regions have different thermal conductivities
Implementation Method 2
the loss of thermal energy from the electrode to or via the guide roll is at least reduced during the conveying of the electrode through the regions with the lower thermal conductivity
Implementation Method 3
the stresses can be released more quickly at high temperatures than at lower temperatures. High temperatures in the context of embodiments of the invention are especially temperatures of 100° C.-160° C., preferably of 120° C.-150° C.
Implementation Method 4
the stresses, or else stress residues, in the electrode build up mainly in the binder structure thereof. Uncontrolled release of these mechanical stresses can lead to what is called a rebound effect
Data Source
AI summary
A calendering apparatus is provided for the mechanical compacting of an electrode, in particular of a flat form. The calendering apparatus includes a compacting device and a guide roller. The guide roller is configured to feed the electrode to the compacting device during the operation of the calendering apparatus. The guide roller has first regions and second regions in certain parts of its rolling surface, and the first and second regions have different thermal conductivities.