Li-Ion Cathode Material Production With Recycled Wet-Chemical Precursors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing lithium mixed metal oxides for cathode materials in Li-ion batteries generate significant effluents, requiring costly treatment and energy consumption, and often result in poor product density due to the need for organic acids and high-temperature calcination.
Innovation Solution
A process involving a wet chemical precursor preparation step followed by a solid-state lithiation step, where raw metals in metallic form are oxidized to form metal hydroxides, allowing for recycling of the liquid portion and minimizing the need for high-temperature calcination and organic decomposition, with unreacted metals recycled and ammonia produced as a useful by-product.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If co-precipitation process using mixed metal sulphates and alkaline solution is used, then cathode materials can be produced, but significant amounts of Na2SO4-containing effluent are generated requiring costly treatment
Solution Approach 1:
The patent changes the chemical parameters of the reaction system by using carbonate salts instead of sulphate salts, and using ammonium hydroxide instead of sodium hydroxide. This parameter change transforms the effluent composition from Na2SO4 (which cannot be reused) to (NH4)2CO3 (which can be recycled), thereby reducing harmful effluent generation while maintaining production capability
Solution Approach 2:
The patent implements a recovery system where the effluent containing ammonium carbonate is collected, treated, and reused in the reaction system. This closes the material loop, preventing effluent discharge while maintaining continuous production. The unreacted metal salts and ammonia are recovered and fed back into the process
2Manufacturing precision
If ammonia is added as chelating agent to assist in providing correct physical properties of precursor materials, then product quality is improved, but effluent contains ammonia and ammonium requiring costly treatment
Solution Approach 1:
The patent converts the previously harmful ammonia effluent into a beneficial reusable resource. By using ammonium carbonate as the base solution, the ammonia that would have been waste is now part of the reaction system's chemistry, forming soluble ammonium carbonate effluent that can be easily recycled back into the process, thus converting a harmful discharge into a beneficial cycle
3Ease of manufacture
If conventional calcination process is used to produce final lithium mixed metal oxide material, then cathode active material is obtained, but significant energy consumption is required
Solution Approach 1:
The patent changes the thermal parameters of the processing by using spray drying at lower temperatures instead of conventional high-temperature calcination. The spray drying process rapidly evaporates solvent at moderate temperatures, forming dry precursors that require less energy for subsequent heat treatment, thereby reducing overall energy consumption while maintaining product quality
4Manufacturing precision
If filtration operation is carried out to separate solid from liquid, then solid precursor is obtained, but liquid effluent containing Na2SO4 cannot be reused and must be treated as waste
Solution Approach 1:
The patent changes the chemical composition parameters of the reaction system by replacing sodium sulphate with ammonium carbonate. This parameter change fundamentally alters the effluent properties from non-reusable Na2SO4 solution to reusable ammonium carbonate solution, which can be recycled back into the reaction system, thereby eliminating substance loss and waste treatment requirements
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 approach reduces effluent generation, conserves energy, and produces high-quality cathode materials with uniform elemental distribution, achieving efficient and environmentally friendly production of lithium mixed metal oxides with improved density and performance.
Implementation Method 1
raw metals in metallic form are oxidized to form metal hydroxides
Implementation Method 2
allowing for recycling of the liquid portion and minimizing the need for high-temperature calcination
Implementation Method 3
unreacted metals recycled
Implementation Method 4
ammonia produced as a useful by-product
Data Source
AI summary
This invention provides an environmental friendly method for the production of high capacity cathode materials for use in Li-ion batteries. Traditional methods for producing lithium mixed metal oxide cathode materials typically generate large amounts of effluent which effluent must be treated prior to discharge. The present process uses mixed metals as raw materials, in a wet chemical reaction with an oxidant, in order to make high-quality metal hydroxide precursors which can be used to prepare high-quality cathode materials after lithiation. As a key feature, in the precursor preparation process, the bulk of the aqueous solution used for the wet chemical reaction can be recycled back to the reactor, so that the total process has little or no effluent generated during production of the cathode precursor material.