Single-Crystal NMC Cathode Recycling Without Acid Leaching
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Solution Overview
Problem
The increasing adoption of lithium ion batteries poses challenges for raw resource supply chains, particularly cobalt, and the accumulation of spent cathode materials threatens the environment, with conventional recycling methods being costly, energy-intensive, and environmentally hazardous.
Innovation Solution
A solid-state recycling method involving heating cathode materials in an oxygen-containing atmosphere, combining them with lithium compounds, and adjusting compositions to form monocrystalline lithium nickel manganese cobalt oxide, reducing the need for acids and alkalis and minimizing toxic byproducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional hydrometallurgical processes are used to recycle spent cathode materials, then the materials can be decomposed and remanufactured, but the process requires large amounts of acid and alkaline chemicals, is energy-intensive, and causes environmental pollution
Solution Approach 1:
The patent changes the fundamental parameters of the recycling process by replacing wet chemical methods with solid-state thermal processing. The cathode materials are heated in an oxygen-containing atmosphere at temperatures of 400-1000°C to convert them to solid precursors, eliminating the need for large amounts of acid and alkaline chemicals while maintaining effective material recovery and reuse
Solution Approach 2:
The invention utilizes phase transitions through solid-state heating and calcination processes. Spent cathode materials undergo thermal decomposition and phase transformation when heated in oxygen-containing atmospheres, converting them into solid precursor materials that can be directly reused in new cathode synthesis without requiring dissolution and precipitation steps
2Ease of manufacture
If conventional hydrometallurgical processes are used to recycle spent cathode materials, then the materials can be recovered, but the process involves multiple steps and is costly
Solution Approach 1:
The patent merges multiple separate recycling steps into a single integrated solid-state thermal processing operation. Instead of separate decomposition, filtration, precipitation, and calcination steps, the invention combines these functions into one continuous heating process in an oxygen-containing atmosphere, reducing process complexity and operational costs
Solution Approach 2:
The invention extracts and eliminates unnecessary intermediate steps from conventional recycling processes. By directly converting spent cathode materials into solid precursors through thermal treatment, the process removes the need for chemical dissolution, filtration, and precipitation steps, achieving material recovery with fewer operations
3Productivity
If conventional hydrometallurgical processes are used to recycle spent cathode materials, then the materials can be processed, but toxic byproducts and corrosive waste are produced
Solution Approach 1:
The patent converts the harmful effect of thermal energy, which would normally cause uncontrolled decomposition, into a beneficial process by using controlled solid-state heating in an oxygen-containing atmosphere. This approach transforms spent cathode materials into useful solid precursors while avoiding the generation of toxic byproducts and corrosive waste associated with chemical methods
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 reduces environmental risk, lowers costs, and produces high-performance monocrystalline cathode materials with comparable discharge capacities and coulombic efficiencies to pristine materials, offering a more efficient and sustainable recycling process.
Implementation Method 1
heating a cathode material comprising lithium nickel manganese cobalt oxide in an oxygen-containing atmosphere at a temperature T1 for an effective period of time t1 to convert the cathode material to a solid precursor
Implementation Method 2
heating the solid precursor and the lithium compound in an oxygen-containing atmosphere at a temperature T2 for an effective period of time t2 to form a product comprising monocrystalline lithium nickel manganese cobalt oxide
Data Source
AI summary
A solid-state method for recycling spent and/or scrap cathode material includes heating a cathode material comprising lithium nickel manganese cobalt oxide in an oxygen-containing atmosphere at a temperature T1 for an effective period of time t1 to convert the cathode material to a solid precursor, combining the solid precursor with a lithium compound, and heating the solid precursor and the lithium compound in an oxygen-containing atmosphere at a temperature T2 for an effective period of time t2 to form a product comprising monocrystalline lithium nickel manganese cobalt oxide having a formula LiNixMnyMzCo1-x-y-zO2, where M represents one or more dopant metals, x≥0.33, 0.01≤y<0.33, 0≤z≤0.05, and x+y+≤z 1.0.