Resin Current Collector with Recessed Conductive Layer for Battery Electrodes
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Solution Overview
Problem
The existing electrode structure for lithium ion secondary cells has insufficient contact resistance reduction between the electrically conductive resin layer and the active material layer, and it is challenging to apply a resin current collector uniformly across the entire current collector.
Innovation Solution
A resin current collector with an electrically conductive layer having a configuration of recesses and projections is applied, where the average height of these features is between 0.1 µm and 20 µm, and the average inclination angle is optimized to enhance contact locations with the active material particles, reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an electrically conductive resin layer is formed on the current collector to improve adhesion, then adhesion between current collector and active material layer is improved, but contact resistance between the resin layer and active material layer is not sufficiently reduced
Solution Approach 1:
The invention applies surface curvature by forming recesses and projections on the electrically conductive resin layer surface. The average inclination angle of these surface features is controlled at 10° or more to enhance mechanical interlocking with active material particles, thereby improving both adhesion and reducing contact resistance simultaneously.
Solution Approach 2:
The invention implements local quality by creating non-uniform surface features (recesses and projections) with specific geometric characteristics on the resin layer. The average height of 0.1-20 µm and inclination angle of 10° or more are locally optimized to provide enhanced contact points with active material particles in critical areas.
2Strength
If a resin current collector is applied to improve adhesion, then adhesion is improved, but it is not possible to apply the resin current collector uniformly across the entire current collector
Solution Approach 1:
The invention applies parameter changes by controlling the average height of recesses and projections within 0.1-20 µm and the average inclination angle at 10° or more. These parameter optimizations enable uniform application of the resin current collector while maintaining effective adhesion properties across the entire surface.
Data Source
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AI summary
An electrode for a cell includes a resin current collector that is planate and contains a resin and an electrically conductive filler, and an electrode active material layer that is disposed on at least one surface side of the resin current collector and that contains electrode active material particles. The resin current collector includes an electrically conductive layer on its surface side facing the electrode active material layer, the electrically conductive layer having configuration with recesses and projections. This configuration with recesses and projections satisfies the relationship given by formula (1): h / tan θ < D (in this formula, h is the average height of the configuration with recesses and projections, θ is the average inclination angle of the configuration with recesses and projections, and D is the average particle diameter of the electrode active material particles). A cell includes the electrode for a cell described above.