Recovered Li-Ion Anode Material for Fast Charge-Discharge
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Solution Overview
Problem
Conventional methods for reproducing negative electrode active materials from used lithium ion secondary batteries do not adequately address the requirement for improved rapid charge-discharge properties.
Innovation Solution
A method involving the preparation of a used lithium ion secondary battery, followed by charging at a lower rate and discharging at a higher rate to amorphize the surface layer of the negative electrode active material, which is then recovered, enhancing its rapid charge-discharge performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional recovery methods are used to reproduce negative electrode active material, then the recovery process is simple, but the rapid charge-discharge property is insufficient
Solution Approach 1:
The patent applies preliminary action by performing a specific charging process before recovery to amorphize the surface layer of the carbon material. The charging step is conducted in advance to modify the crystal structure, creating an amorphous surface layer that enhances rapid charge-discharge properties before the actual material recovery takes place.
Solution Approach 2:
The patent applies parameter changes by controlling the charging potential range (0.01V to 1.5V vs. Li/Li+) and charging capacity (10Ah to 50Ah) to transform the crystal structure of the carbon material surface. By adjusting these charging parameters, the surface layer transitions from a crystalline to an amorphous state, improving ion insertion/extraction kinetics.
2Speed
If the negative electrode active material is discharged at a high rate, then the surface layer is amorphized improving rapid charge-discharge property, but the charging process becomes more complex
Solution Approach 1:
The patent uses preliminary action by performing the amorphizing charging process before material recovery. This pre-treatment modifies the surface structure in advance, enabling the material to achieve better rapid charge-discharge performance without requiring complex post-processing or additional treatment steps.
Solution Approach 2:
The patent exploits phase transitions by inducing a structural transformation from crystalline to amorphous phase in the surface layer of the carbon material through controlled charging. This phase transition occurs when lithium ions are inserted at specific potentials, creating an amorphous surface structure that facilitates faster ion transport.
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 method effectively improves the rapid charge-discharge performance of the recovered negative electrode active material by amorphizing its surface layer, making it suitable for high-performance applications.
Implementation Method 1
the lithium ion secondary battery is discharged at a discharge rate higher than the charge rate, so that a surface layer of the negative electrode active material of the negative electrode is amorphized
Data Source
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AI summary
The present disclosure relates to a reproduction method for obtaining a negative electrode active material with improved rapid charge-discharge property, from a used lithium ion secondary battery. A technology disclosed herein is directed to a reproduction method for a negative electrode active material from a used lithium ion secondary battery, including: a preparation step of preparing the used lithium ion secondary battery including a positive electrode, a negative electrode including a negative electrode active material containing a carbon material, and an electrolyte; a charging step of charging the lithium ion secondary battery; a discharging step of discharging the lithium ion secondary battery obtained after the charging step, at a discharge rate higher than a charge rate of the charging step; and a recovery step of recovering the negative electrode active material containing the carbon material from the negative electrode in the lithium ion secondary battery obtained after the discharging step.