Negative Electrode Material Recovery for Fast Charge-Discharge
Find Innovative SolutionsGenerate Solutions
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 reproduction method involving charging and discharging the lithium ion secondary battery at specific rates to amorphize the surface layer of the negative electrode active material, followed by recovery, which includes steps like roasting, sorting, acid treatment, and magnetic force sorting to obtain a negative electrode active material with enhanced rapid charge-discharge performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
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 charging at a first rate followed by discharging at a second rate higher than the first rate before recovery. This pre-treatment modifies the surface layer of the carbon material to improve rapid charge-discharge properties, achieving the desired performance enhancement without complicating the overall recovery process
2Speed
If the battery is discharged at a higher rate than charge rate, then the surface layer of negative electrode active material is amorphized improving rapid charge-discharge property, but the process requires additional charging and discharging steps
Solution Approach 1:
The patent utilizes parameter changes by varying the discharge rate to be higher than the charge rate, which transforms the surface layer of the carbon material from crystalline to amorphous state. This parameter change (rate differential) achieves improved rapid charge-discharge properties while the additional time required is offset by the simplicity of the process steps
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, leading to better lithium ion insertion and detachment capabilities.
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
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.