Dry-Mixed Battery Electrode With Dual-Binder Strength and Conductivity
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Solution Overview
Problem
Conventional electrodes for secondary batteries, particularly those manufactured in a wet manner, face challenges such as damage to metal oxides during high-temperature heat treatment and require improved tensile strength and resistance reduction.
Innovation Solution
The use of a dual-binder system comprising polytetrafluoroethylene (PTFE) as a first binder and an acrylic polymer as a second binder, with distinct glass transition temperatures, allows for dry mixing and enhances tensile strength and resistance reduction by controlling fiberization and agglomeration in the electrode composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a wet manufacturing process is used for electrodes, then the electrode composition can be uniformly mixed, but high-temperature heat treatment is required which may damage metal oxide and reduces manufacturing efficiency
Solution Approach 1:
The patent extracts and eliminates the solvent from the electrode manufacturing process, transitioning from a wet process to a dry process. This removes the need for high-temperature heat treatment while maintaining composition uniformity through direct dry mixing of electrode materials, binders, and conductive agents.
Solution Approach 2:
The patent replaces the thermal field (heat treatment) with a mechanical field (intense mixing). By using high-shear mixing and intensive mechanical agitation, the electrode composition achieves uniformity without requiring high-temperature heat treatment, thus avoiding metal oxide damage and improving manufacturing efficiency.
2Device complexity
If conventional single-binder systems are used in dry electrodes, then the manufacturing process is simplified, but tensile strength and resistance reduction are insufficient
Solution Approach 1:
The patent employs a composite binder system consisting of multiple binder materials with different functions. This composite approach combines the advantages of each binder type to achieve both adequate mechanical strength (tensile strength) and electrical performance (resistance reduction) while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent segments the binder function into multiple components, where each binder material performs specific functions (e.g., one binder provides mechanical strength while another enhances conductivity). This functional segmentation allows the electrode to achieve both high tensile strength and good resistance reduction without requiring a single complex binder material.
3Stability of the object's composition
If high-temperature heat treatment is applied during wet manufacturing, then the electrode structure is stabilized, but metal oxide may be damaged and energy consumption increases
Solution Approach 1:
The patent replaces thermal stabilization (heat treatment) with mechanical stabilization through intensive mixing. The dry mixing process, using high-shear forces and repeated agitation, creates a stable electrode structure without exposing metal oxide to high temperatures that could cause damage or phase changes.
Solution Approach 2:
The patent changes the processing parameters from high-temperature thermal treatment to room-temperature or low-temperature mechanical mixing. By adjusting the mixing intensity, duration, and mechanical energy input, the electrode achieves structural stability without the harmful effects of high-temperature heat treatment on metal oxide materials.
4Object-affected harmful factors
If dry mixing is used for electrode manufacturing, then heat treatment damage is avoided, but achieving sufficient tensile strength and conductivity is more difficult
Solution Approach 1:
The patent uses a composite binder system specifically designed for dry-mixed electrodes. This composite binder formulation provides adequate tensile strength to the electrode structure while maintaining good electrical conductivity, overcoming the typical limitations of dry-mixing processes without requiring heat treatment.
Solution Approach 2:
The patent introduces conductive binders and conductive agents as intermediaries that facilitate electrical conductivity in the dry-mixed electrode. These intermediary materials bridge the electrode active materials and current collector, ensuring sufficient conductivity is achieved through mechanical mixing alone without compromising the electrode's tensile strength.
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 dual-binder system improves the tensile strength and resistance reduction of secondary battery electrodes, ensuring better flexibility and conductivity, thereby enhancing the battery's performance and lifespan.
Implementation Method 1
The first binder and the second binder have distinct glass transition temperatures
Data Source
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AI summary
An electrode for secondary battery according to an embodiment of the present disclosure includes an electrode current collector; and an electrode layer located on the electrode current collector, wherein the electrode layer comprises an electrode composition in which an active material, a conductive material, and a binder are dry-mixed, wherein the binder comprises a first binder and a second binder, with the first binder and the second binder being different from each other, and wherein the second binder is attached to the surface of the first binder.