Transition Metal Oxide Delithiation Using Strong Oxidizers at High pH
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Solution Overview
Problem
Existing methods for delithiating electrochemically active compositions in batteries suffer from high costs and low yields, typically achieving only about 50% yield.
Innovation Solution
A process involving the combination of an electrochemically active composition, such as LiNiO2, with a strong oxidizer at elevated pH to achieve lithium removal, resulting in a delithiated composition with a reduced Li/Ni atomic ratio, using oxidizers like hypochlorite salts or ozone, and optionally recycling the removed lithium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional acid wash methods are used to remove lithium from electrochemically active compositions, then lithium removal is achieved, but the yield is low (approximately 50%) and the process cost is high
Solution Approach 1:
The patent changes the chemical parameters of the treatment process by using basic conditions (pH 12-14) with strong oxidizers instead of traditional acidic conditions. This parameter change transforms the delithiation mechanism while preserving more nickel in the solid phase, achieving both effective lithium removal and higher material yield (>50%).
Solution Approach 2:
The patent employs strong oxidizers such as hypochlorite salts, ozone, or persulfates to accelerate the oxidation of lithium-containing phases during delithiation. This enables more complete and efficient lithium removal at basic pH, resolving the contradiction between lithium removal efficiency and material yield by providing a more effective chemical pathway that minimizes nickel loss.
2Loss of substance
If traditional acid wash methods are used to delithiate electrochemically active compositions, then lithium is removed, but the process cost is high
Solution Approach 1:
The patent shifts from acidic to basic conditions (pH 12-14) and uses readily available strong oxidizers, which are generally more cost-effective than the specialized acids traditionally used for delithiation. This parameter change simplifies the manufacturing process and reduces costs while maintaining effective lithium removal.
Solution Approach 2:
The patent employs inexpensive oxidizing agents such as hypochlorite salts (e.g., sodium hypochlorite), ozone, or persulfates that can be easily prepared or obtained at low cost. These reagents effectively perform the delithiation function without requiring expensive specialized chemicals, thereby reducing overall process cost.
3Productivity
If strong oxidizers are used at elevated pH for lithium removal, then nickel yield and capacity are enhanced, but process complexity increases
Solution Approach 1:
The patent uses strong oxidizers at basic pH to achieve superior nickel yield and capacity by preventing nickel dissolution and promoting complete lithium removal. While this introduces new reagents, the process remains relatively simple by avoiding multi-step procedures and using readily available chemicals, thus managing complexity while enhancing productivity.
Solution Approach 2:
The patent optimizes pH (12-14) and oxidizer concentration to maximize nickel yield while maintaining process simplicity. By carefully controlling these parameters within specific ranges, the process achieves high productivity without requiring overly complex process design, balancing yield enhancement with operational simplicity.
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 process enhances nickel yield and capacity, achieving yields greater than 50% and capacities above 250 mAh/g, while maintaining the crystal structure of the cathode material.
Implementation Method 1
combining the electrochemically active composition with a strong oxidizer for a lithium removal time
Data Source
AI summary
Provided are processes of removing lithium from an electrochemically active composition. The process of removing lithium from an electrochemically active composition may include providing an electrochemically active composition and combining the electrochemically active composition with a strong oxidizer optionally at a pH of 1.5 or greater for a lithium removal time. The electrochemically active composition may include Li, Ni, and O. The electrochemically active composition may optionally have an initial Li/M at % ratio of 0.8 to 1.3. According to some embodiments of the present disclosure, the lithium removal time may be such that a second Li/M at % ratio following the lithium removal time is 0.6 or less, thereby forming a delithiated electrochemically active composition.