Wet Lithium Battery Recycling via Acid Leaching and Metal Separation
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Solution Overview
Problem
Existing technologies for recycling lithium batteries are inefficient, costly, and environmentally harmful due to complex processes, low recycling efficiency, and the presence of toxic substances.
Innovation Solution
A wet method for recycling metal elements from lithium batteries, involving pretreatment, acid leaching, and subsequent steps such as heating and extraction using diisooctyl phosphate, to separate and recover valuable metals like lithium, nickel, cobalt, and manganese.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing recycling technologies are used, then lithium batteries can be processed, but the treatment process becomes complicated and recycling efficiency decreases
Solution Approach 1:
The recycling process is divided into distinct stages: pyrolysis treatment, acid leaching, and precipitation. Each stage targets specific components of the lithium battery, allowing for systematic processing while maintaining overall efficiency. The pyrolysis stage separates organic materials, the leaching stage extracts metal ions, and the precipitation stage recovers pure metal products.
Solution Approach 2:
The invention uses controlled changes in chemical parameters (acid concentration, temperature, pH) to optimize each processing stage. By adjusting these parameters, the process achieves high recycling efficiency without requiring overly complex equipment or multiple processing steps.
2Quantity of substance
If existing recycling methods are applied, then metals can be recovered, but recycling costs increase
Solution Approach 1:
The pyrolysis process simultaneously achieves multiple objectives: it removes organic binders and electrolytes, concentrates metal elements in the remaining powder, and prepares the material for efficient leaching. This self-service approach reduces the need for additional separate treatment steps, lowering overall processing costs while maximizing metal recovery.
Solution Approach 2:
The invention converts harmful toxic substances (electrolytes, binders, heavy metals) into beneficial outcomes. The pyrolysis process transforms toxic organic materials into removable volatiles and concentrates valuable metals. The acid leaching then selectively extracts metal ions while leaving harmful residues behind, turning environmental hazards into separation advantages.
3Object-affected harmful factors
If discarded lithium batteries are not treated, then toxic substances remain in the environment, but recycling processes may spread pollution
Solution Approach 1:
The pyrolysis process is conducted in an oxygen-free inert atmosphere, preventing combustion of toxic substances and avoiding the generation of harmful combustion products. This controlled environment ensures that toxic materials are decomposed safely without creating additional pollution, while still achieving effective separation and concentration of valuable metals.
Solution Approach 2:
The invention uses acid leaching solution as an intermediary medium to selectively extract metal ions from the pyrolyzed powder. This intermediary step separates valuable metals from harmful residues, allowing the toxic substances to remain in the solid residue while metal ions are transferred to the solution for pure recovery, thus preventing pollution spread.
4Adaptability or versatility
If manual pre-separation of battery types is performed, then recycling can be targeted, but the pretreatment process becomes more complex
Solution Approach 1:
The pyrolysis process serves as a universal pretreatment method that works effectively for all types of lithium batteries regardless of their specific chemistry (lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, etc.). This single-step universal treatment eliminates the need for manual battery type identification and separate processing lines, reducing pretreatment complexity while maintaining adaptability to different battery compositions.
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 achieves high recycling efficiency, allows for the direct reuse of recycled materials in producing new cathode materials, and reduces environmental pollution by effectively managing toxic substances.
Implementation Method 1
in the Step 1, oxygen-free pyrolysis is used to remove binder, so as to separate positive-electrode active materials from current collectors
Implementation Method 2
Step 2, acid leaching to obtain leachate
Implementation Method 3
the solid products, obtained after acid leaching and solid-liquid filtration, are heated in an oxygen-containing atmosphere, so as to burn up carbon
Implementation Method 4
the leachate, obtained after acid leaching and solid-liquid filtration, is sent to an extraction step, wherein diisooctyl phosphate is used as extraction agent, so as to obtain a raffinate containing Li element and an organic phase containing Ni/Co/Mn elements
Implementation Method 5
the back-extraction is performed on the organic phase containing Ni/Co/Mn elements, wherein sulfuric acid aqueous solution is used as the back-extraction agent, so as to obtain a first stripping solution containing Ni/Co/Mn elements
Implementation Method 6
by adding a precipitating agent of sodium carbonate into the raffinate containing Li element, precipitation of lithium carbonate is obtained
Data Source
AI summary
The present invention provides a method of using a wet method to recycle metal elements in lithium batteries, including the following steps: Step 1, pretreating lithium batteries, so as to obtain a mixture of powders containing positive-electrode materials; Step 2, acid leaching to obtain leachate; Step 3, if the to-be-recycled lithium battery contain a lithium iron phosphate battery, the solid products, obtained after acid leaching and solid-liquid filtration, are heated in an oxygen-containing atmosphere, so as to burn up carbon, then the left is ferric phosphate; Step 4, if the to-be-recycled lithium battery contains a ternary lithium battery, the leachate, obtained after acid leaching and solid-liquid filtration, is sent to an extraction step, wherein diisooctyl phosphate is used as extraction agent, so as to obtain a raffinate containing Li element and an organic phase containing Ni/Co/Mn elements.