Battery Recycling Solvent Removal Under Low-Temperature Vacuum
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Solution Overview
Problem
Existing battery recycling methods are complex, expensive, and inefficient in separating low-boiling and high-boiling solvents from lithium-ion batteries, often requiring high temperatures and multiple processing steps, which can lead to hazardous conditions and material alteration.
Innovation Solution
A method and processing plant that involves shredding batteries under inert gas and slight negative pressure, followed by thermal treatment in a drying container where ambient temperature and pressure are controlled to evaporate solvents below 200°C, allowing simultaneous separation of both low-boiling and high-boiling solvents without material melting, using a single drying chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pyrolysis is used at very high decomposition temperatures (up to 900°C) to decompose binder and recover active material, then active material recovery is improved, but process complexity and cost increase, and unpleasant odors are generated
Solution Approach 1:
The patent changes the temperature parameter from very high (900°C) to moderate (80-200°C) and combines it with pressure reduction (vacuum) to achieve solvent removal without pyrolysis, thus recovering active material while simplifying the process and avoiding odors
Solution Approach 2:
The patent extracts and removes the electrolyte solvents (both low-boiling and high-boiling) from the battery material before further processing, separating the solvent removal function from the active material recovery function to enable simpler subsequent processing
2Use of energy by moving object
If low drying temperatures (approximately 80°C or less) are used in thermal pretreatment, then energy consumption is reduced, but only low-evaporating or low-boiling solvents can be separated from the electrolyte
Solution Approach 1:
The patent changes the pressure parameter (reduces pressure to vacuum conditions) to enable high-boiling solvents to evaporate at low temperatures, thus achieving complete solvent separation without increasing energy consumption
Solution Approach 2:
The patent utilizes phase transition (evaporation) of both low-boiling and high-boiling solvents under vacuum conditions at low temperature, allowing complete solvent removal without requiring high energy input
3Quantity of substance
If very high evaporation temperatures are used to remove high-boiling solvents from electrolyte, then complete solvent removal is improved, but plastic-containing substances in the material being ground begin to melt, altering the material undesirably
Solution Approach 1:
The patent simultaneously changes pressure (reduces to vacuum) and temperature (keeps low) parameters to create conditions where high-boiling solvents evaporate without reaching temperatures that would melt plastic-containing substances, thus removing solvents completely while preserving material composition
4Quantity of substance
If multiple processing steps and additional containers are used to separate low-boiling and high-boiling solvents, then solvent separation completeness is improved, but process complexity and processing time increase
Solution Approach 1:
The patent merges the separation of low-boiling and high-boiling solvents into a single thermal pretreatment step under vacuum conditions, eliminating the need for multiple processing steps and additional containers while achieving complete solvent removal
Solution Approach 2:
The patent creates a universal thermal pretreatment process under vacuum that simultaneously handles both low-boiling and high-boiling solvent removal, making the process applicable to all electrolyte compositions without requiring step-specific modifications
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
This approach reduces processing complexity and cost by ensuring efficient solvent separation in a single step, minimizing hazards and material alteration, and optimizing energy transfer for faster and more complete solvent evaporation.
Implementation Method 1
the provided batteries and/or the resulting shredded material are heated in the shredding chamber to a shredding temperature
Implementation Method 2
the ambient temperature and pressure are controlled in the drying container such that the material to be ground heats up and solvents contained in the material to be ground can evaporate
Implementation Method 3
shredding the provided battery to be recycled to obtain shredded material, preferably in a shredding chamber under inert gas and a slight negative pressure
Implementation Method 4
a mixing device (4d) for loosening and/or mixing the material to be ground (101) in the drying container (4a)
Implementation Method 5
at least one heater (4b), at least partially located in or on the drying container (4a), for increasing the ambient temperature in the drying container (4a)
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for preparing batteries (100) to be recycled, having at least the following steps: - comminuting a provided battery (100) to be recycled in order to obtain comminuted material (101), the provided battery (100) to be recycled and/or the comminuted material (101) obtained therefrom being thermally pre-treated in a comminuting chamber (3a) by being heated up to a comminuting temperature (TZ) which is lower than 100 °C; - transferring the comminuted material (101) into a drying container (4a) and thermally treating the comminuted material (101) by raising the actual ambient temperature (TActual) and lowering the actual ambient pressure (pActual) in the drying container (4a) in order to heat the comminuted material (101) in the drying container (4a), wherein the actual ambient temperature (TActual) in the drying container (4a) is set such that the comminuted material (101) is heated to no higher than 200 °C, the actual ambient pressure (pActual) in the drying container (4a) is set such that both the low-boiling solvent (LL) as well as the high-boiling solvent (LH) are separated by being evaporated out of the comminuted material (101) at the set actual ambient temperature (TActual), and the low-boiling solvent (LL) and the high-boiling solvent (LH) are discharged out of the same drying container (4a) during the thermal treatment of the comminuted material (101); and - mechanically preparing the thermally treated comminuted material (101).