Battery Electrode Scrap Recycling via Thermal Expansion Separation
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Solution Overview
Problem
The production of lithium-ion battery electrodes generates waste materials that are difficult to recycle efficiently, as they consist of metallic foils coated with active materials, requiring a method to separate and recover the valuable components while managing different thermal expansion properties.
Innovation Solution
A recycling process that separates and thermally treats waste electrode pieces, utilizing their differing thermal expansion coefficients to detach the active material from the metallic foil, followed by gas flow or brushing for separation, and potentially using roll-to-roll processing or shredding, with heat treatment temperatures between 100°C to 300°C and under controlled atmospheres, to recover the metallic material for reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If thermal treatment is applied to separate active material from metallic foil, then material recovery is improved, but energy consumption increases due to heating requirements
Solution Approach 1:
The patent applies parameter changes by controlling thermal treatment temperature (100-300°C) and atmosphere (inert or vacuum) to optimize the separation of active material from metallic foil. This controlled parameter approach enables effective material recovery while minimizing energy consumption by using the lowest effective temperature and preventing oxidative reactions that would require additional energy input.
Solution Approach 2:
The patent uses an inert atmosphere (nitrogen or argon) or vacuum environment during thermal treatment to prevent oxidation of the metallic foil and active material. This eliminates the need for additional energy-consuming processes to remove oxidation products and allows direct recovery of high-purity materials, thus improving material recovery efficiency while keeping energy consumption low.
2Productivity
If different types of waste pieces are collected and treated separately, then recycling efficiency is improved, but process complexity increases
Solution Approach 1:
The patent segments waste pieces into different types (strip-type, offcut-type, and electrode-type) and processes each type through appropriate thermal treatment conditions. This segmentation allows optimization of recycling efficiency for each waste category while maintaining a relatively simple overall process structure by using a single thermal treatment unit that can accommodate different waste types with adjusted parameters.
3Manufacturing precision
If thermal treatment temperature is increased to ensure complete separation, then separation completeness is improved, but risk of material degradation increases
Solution Approach 1:
The patent optimizes the thermal treatment temperature parameter to the range of 100-300°C, which is sufficient to ensure complete separation of active material from metallic foil through thermal expansion differences, while remaining below the degradation temperatures of these materials. This precise parameter control achieves complete separation without causing material degradation.
Solution Approach 2:
By conducting thermal treatment in an inert atmosphere (nitrogen or argon) or vacuum, the patent prevents oxidative degradation of the metallic foil and active material that would occur at elevated temperatures. This allows the use of higher temperatures within the 100-300°C range to ensure complete separation while protecting materials from thermal and oxidative degradation.
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
Effectively recycles lithium-ion battery electrode waste, recovering the metallic foils for reuse and separating the active material for re-use in new electrodes, while minimizing environmental impact and optimizing material recovery.
Implementation Method 1
The recycling process is preferably applied to waste pieces in which the metallic material of the foil pieces and the electrode active material have different thermal expansion properties, in particular different linear expansion coefficients. In this case, the different thermal expansion properties, in particular the different linear expansion coefficients, are exploited to detach the electrode active material from the foil pieces.
Implementation Method 2
In some cases, it is also useful to carry out the thermal treatment under special environmental conditions, where the waste pieces are not exposed to the ambient air. Instead, the thermal treatment takes place, for example, under a protective gas atmosphere or under vacuum conditions.
Data Source
Figure 1~2
AI summary
The invention relates to a method for the utilization of waste generated during the manufacture of electrodes for lithium-ion batteries, wherein material strips are produced during the manufacturing process, each material strip comprising a foil made of a metallic material 4 coated with an electrode active material 6, wherein pieces 2 of the material strips are generated as waste during the manufacturing process and are collected separately for utilization, wherein each piece 2 comprises a foil piece on which electrode active material 6 is applied, and wherein, for utilization, the pieces 2 are subjected to a thermal treatment to detach the electrode active material 6 from the foil sections.