Battery Material Recovery via Charged Li-Ion Cell Aqueous Elution
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Solution Overview
Problem
The existing methods for collecting lithium (Li) from used lithium ion secondary batteries often result in reduced Li collection rates due to the formation of Li—Al alloys during the roasting process, which hinder the dissolution of Li in acid liquids.
Innovation Solution
A manufacturing method for battery materials that involves electrically charging lithium ion secondary batteries to a predetermined State of Charge (SOC), filling the inside of the battery with an aqueous medium, and collecting this medium to elute Li from the negative electrode active material, thereby enhancing Li collection efficiency before the roasting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electric discharge is performed on the lithium ion secondary battery before collection processing, then the Li is stored on the positive electrode active material, but this causes formation of Li-Al alloy during roasting which reduces Li collection rate
Solution Approach 1:
Instead of discharging the battery to store Li on the positive electrode (conventional method), the invention inverts the approach by charging the battery to store Li on the negative electrode. This inversion prevents Li-Al alloy formation during subsequent roasting while maintaining high Li collection rates through acid exudation processing.
2Ease of manufacture
If the battery is roasted in the state with Li stored on positive electrode, then the roasting process can be performed, but Li-Al alloy is generated which is hardly dissolved in acid liquid
Solution Approach 1:
The invention performs preliminary charging action before roasting to store Li on the negative electrode active material. This preliminary action ensures that during subsequent roasting and acid exudation, Li remains in a form that is easily dissolved, preventing the formation of insoluble Li-Al alloys and ensuring high collection efficiency.
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 method significantly improves the Li collection rate by ensuring Li is stored in the negative electrode active material, allowing for easy elution into an aqueous medium, and preventing the formation of Li—Al alloys, thus reducing the risk of reduced collection rates.
Implementation Method 1
the Li in the negative electrode active material is eluted into the aqueous medium
Data Source
AI summary
A manufacturing method disclosed herein includes a preparing step at which a lithium ion secondary battery having been electrically charged to be equal to or more than a predetermined reference SOC is prepared, a filling step at which an inside of the lithium ion secondary battery is filled with an aqueous medium, and a collecting step at which the aqueous medium is collected from the inside of the lithium ion secondary battery. By doing this, it is possible to prepare a Li solution in which Li of a negative electrode active material is eluted into the aqueous medium. Then, by collecting this Li solution, it is possible to easily perform collection of a large amount of Li.