Solid-State Battery Recycling Using Solvent-Based Lithium Recovery
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Solution Overview
Problem
Current recycling methods for solid-state lithium batteries are inefficient and resource-intensive, particularly due to the need for complete consumption of metallic lithium and the inability to recycle batteries with varying discharge states, leading to unsuitable materials for further processing.
Innovation Solution
A method involving the separation of solid-state lithium batteries into a mixture of lithium anode, cathode material, and solid electrolyte, followed by the use of aprotic and protic solvents to form lithium salts, allowing for controlled processing and utilization of lithium without external sources, enabling recycling regardless of discharge state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If complete consumption of metallic lithium is required for recycling, then the recycling process can proceed, but batteries with varying discharge states cannot be recycled and external lithium sources are needed
Solution Approach 1:
The method enables the battery system to serve itself by using the lithium contained within the battery to react with protic solvent and form lithium salts, which then serve as the lithium source for recathodizing the cathode material. This self-service approach eliminates the need for external lithium sources and allows recycling of batteries regardless of their discharge state.
Solution Approach 2:
The invention changes the chemical state of lithium from metallic form to lithium salt form through reaction with protic solvent. This parameter change allows the lithium to be transferred in a controlled manner to the cathode material, enabling flexible processing of batteries with varying discharge states without requiring complete lithium consumption.
2Quantity of substance
If hydrothermal processes with acids are used for recycling, then valuable metals can be dissolved and concentrated, but the process is unsafe and not environmentally friendly
Solution Approach 1:
The invention changes the chemical parameters of the recycling process by replacing acidic hydrothermal conditions with a milder approach using protic solvent at controlled temperatures. This parameter change maintains the ability to dissolve and concentrate valuable metals while eliminating the safety hazards and environmental harm associated with acid handling.
Solution Approach 2:
The method converts the previously harmful acidic digestion process into a beneficial reaction where protic solvent safely reacts with lithium to form lithium salts, which then serve as a useful lithium source for recathodizing the cathode material. This transforms a potentially harmful process into a beneficial one that recovers both metals and lithium.
3Productivity
If pyrometallurgical recycling is used, then batteries can be melted thermally, but the process results in slag and molten alloy requiring further processing
Solution Approach 1:
The invention segments the recycling process into distinct chemical steps: dissolution of solid electrolyte in aprotic solvent, reaction of lithium with protic solvent to form lithium salts, and recathodizing of cathode material. This segmentation allows each step to be optimized independently and eliminates the need for complex thermal processing and multiple subsequent separation steps.
4Reliability
If cathode material is chemically relithiated using lithium carbonate, then the material becomes usable again, but additional resource-intensive steps are required
Solution Approach 1:
The recycled cathode material process is made self-sufficient by using lithium salts generated from the battery's own lithium content to perform the recathodizing reaction. This eliminates the need for external lithium carbonate and other lithium sources, making the recycling process resource-conserving while maintaining the reliability and usability of the recovered cathode material.
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 allows for efficient recycling of cathode material and solid electrolyte, utilizing lithium from the batteries and eliminating the need for external lithium sources, thus being more resource-conserving and environmentally friendly, while enabling the reuse of materials in new battery production.
Implementation Method 1
admixing the solid mixture with an aprotic solvent to form a solution of the solid electrolyte in the aprotic solvent and insoluble constituents
Implementation Method 2
contacting the insoluble constituents with a protic solvent to form a solution of lithium salts of the general formula LiX in the protic solvent and undissolved cathode material, in which X is an alkoxide or a hydroxide ion, where the lithium anode is reacted with the protic solvent to form hydrogen and lithium salts LiX
Implementation Method 3
the lithium salts LiX is dissolved in the protic solvent
Data Source
AI summary
A method for recycling a cathode material and a solid electrolyte from a solid-state lithium battery is provided. The method has the following steps: a) separating the solid-state lithium battery into a solid mixture, said mixture comprising lithium anode, cathode material, and solid electrolyte components, b) mixing the solid mixture with an aprotic solvent, forming a solution of the solid electrolyte in the aprotic solvent and insoluble constituents comprising lithium anode and cathode material, c) separating the solution of the solid electrolyte from the insoluble constituents, d) bringing the insoluble constituents into contact with a protic solvent, forming a solution of lithium salt of the general formula LiX in the protic solvent and undissolved cathode material, e) separating the solution of lithium salt LiX from the undissolved cathode material, and f) calcinating the separated cathode material while adding a lithium compound.