Polymer-Supported Electrode Plate for Bonding and Nail Penetration Safety
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Solution Overview
Problem
Lithium-ion batteries face challenges in achieving high mass energy density and volumetric energy density, and their electrochemical performance and safety are compromised due to the use of conventional metal current collectors, which lead to issues like poor bonding force, internal resistance, and nail penetration safety.
Innovation Solution
The development of an electrode plate with a composite current collector featuring a thin conductive layer and a polymer or polymer composite support layer, along with a conductive primer layer and a specific binder content, enhances energy density, electrochemical performance, and safety by improving bonding force and reducing internal resistance and nail penetration risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional metal current collector is used, then good electrochemical performance is achieved, but mass energy density and volumetric energy density are reduced
Solution Approach 1:
The current collector uses a composite structure consisting of a metal foil base layer (5-12 μm thick) coated with a thin conductive polymer layer (1-10 μm thick). This composite design reduces the overall weight and thickness compared to conventional metal current collectors while maintaining electrochemical performance through the conductive polymer coating that provides both electrical conductivity and mechanical flexibility.
Solution Approach 2:
The patent employs a thin conductive polymer film coating on the metal foil to create a flexible, lightweight current collector. The polymer layer (1-10 μm) is thin enough to reduce weight and increase energy density while still providing sufficient conductivity and mechanical properties for battery operation.
2Weight of moving object
If the conductive layer thickness is reduced to increase energy density, then mass energy density improves, but bonding force between current collector and electrode active material layer deteriorates
Solution Approach 1:
The patent optimizes the conductive polymer layer thickness to a specific range (1-10 μm) that balances conductivity, bonding force, and weight reduction. Within this parameter range, the polymer layer provides sufficient adhesion to the electrode active material while being thin enough to achieve high energy density. The metal foil base layer (5-12 μm) provides mechanical strength to support the thin polymer coating.
Solution Approach 2:
The composite structure of metal foil plus conductive polymer coating creates a hierarchical system where each layer performs its optimal function: the metal foil provides mechanical strength and baseline conductivity, while the thin polymer layer provides enhanced bonding to the electrode material and flexible conductivity, achieving both strong bonding and high energy density.
3Weight of moving object
If a thin conductive layer is used, then energy density increases, but nail penetration safety deteriorates
Solution Approach 1:
The composite current collector combines a metal foil base layer (5-12 μm) with a conductive polymer coating (1-10 μm). The metal foil provides mechanical strength and nail penetration resistance, while the polymer coating provides conductivity and bonding. This composite structure achieves both high energy density and improved safety compared to thin metal foils alone.
Solution Approach 2:
The conductive polymer coating acts as a protective cushion layer between the electrode materials and potential nail penetration events. This polymer layer absorbs and distributes mechanical stress, preventing direct metal-to-metal contact and reducing the risk of internal short circuits during nail penetration tests, thereby improving safety before failure occurs.
Data Source
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AI summary
This application relates to the battery field, and specifically, to an electrode plate, an electrochemical apparatus, and an apparatus. This application relates to an electrode plate, including a current collector and an electrode active material layer disposed on at least one surface of the current collector. The current collector includes a support layer and a conductive layer disposed on at least one surface of the support layer, where single-sided thickness D2 of the conductive layer satisfies: 30 nm ≤ D2 ≤ 3 µm, the support layer includes a polymer material or a polymer composite material, and thickness D1 of the support layer satisfies: 1 µm ≤ D1 ≤ 20 µm.The electrode active material layer includes an electrode active material, a binder, and a conductive agent, where total thickness Dtotal of the electrode active material layer satisfies: 200 ≥ Dtotal/D1≥ 1, and based on total weight of the electrode active material layer, the binder content in the electrode active material layer is not less than 1wt%. The electrode plate in this application has good workability, and the electrochemical apparatus and the apparatus including the electrode plate have high energy density, good electrical performance, and good safety.