Electrode Lamination Structure for Low Resistance and Core Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing electrodes for non-aqueous electrolyte secondary batteries, such as lithium-ion batteries, face challenges in reducing interface resistance while maintaining core strength, as embedding active materials into the core can decrease core strength and lead to uneven binder distribution.
Innovation Solution
An electrode with a core, an electrode mixture, and a conductive adhesive layer, where the active material is embedded to a maximum depth of 20% of the core thickness, and the density of the active material in the electrode mixture is greater than 70%, using a fibrous binder and a dry process to ensure uniform distribution and adherence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If increasing linear pressure to embed active material into the core, then interface resistance is reduced, but core strength decreases
Solution Approach 1:
The patent optimizes the embedding depth parameter by limiting it to 20% or less of the core thickness, and controls the density of active material in the electrode mixture to be 70% or more of its true density. These parameter changes allow achieving low interface resistance without excessive embedding that would compromise core strength.
Solution Approach 2:
The conductive adhesive layer serves as an intermediary between the core and the electrode mixture. This intermediate layer facilitates electrical contact and reduces interface resistance without requiring deep embedding of active material into the core, thereby preserving core strength while achieving good electrical connectivity.
2Ease of manufacture
If using wet method to apply electrode mixture slurry, then coating process is simple, but binder distribution becomes uneven
Solution Approach 1:
The patent replaces the wet coating method with a dry method where the electrode mixture is formed into a sheet and then laminated onto the core. This substitution eliminates the drying process that causes binder migration, achieving uniform binder distribution while maintaining manufacturing simplicity through the lamination process.
3Reliability
If embedding active material into the core, then interface resistance is reduced, but the amount of embedded active material should be limited to maintain core strength
Solution Approach 1:
The patent establishes specific parameter thresholds: embedding depth limited to 20% or less of core thickness, and active material density in the electrode mixture at 70% or more of true density. These parameter changes optimize the balance between achieving sufficient interface contact for low resistance and limiting the quantity of embedded active material to preserve core strength.
Solution Approach 2:
The conductive adhesive layer acts as an intermediary that reduces interface resistance without requiring large amounts of active material to be embedded into the core. This intermediary layer provides the necessary electrical contact while minimizing the quantity of active material consumed in the embedding process.
Data Source
AI summary
The present invention provides an electrode which is capable of reducing the interface resistance, while ensuring the strength of a core material by suppressing the amount of biting of an active material into the core material. An electrode according to one embodiment of the present disclosure comprises a core material, an electrode mixture that is superposed on the surface of the core material, and a conductive bonding layer that is formed between the core material and the electrode mixture: the electrode mixture comprises an active material and a fibrous binder; the active material bites into the core material; the maximum bite depth is 20% or less of the thickness of the core material; and the ratio of the density of the active material in the electrode mixture to the true density of the active material is 70% or more.