Lithium-Ion Cathode Precursors for Controlled Manganese Oxidation
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Solution Overview
Problem
Current methods for producing cathode materials for lithium ion batteries, such as NMC, are costly and inefficient due to the use of expensive transition metal precursors and complex multi-step processes, leading to high production costs and limited control over cation mixing, which affects the electrochemical performance.
Innovation Solution
A method involving the use of carboxylate precursors, specifically acetates and citrates, derived from pure metals or metal compounds, which are reacted to form oxide materials through liquid or solid phase reactions, allowing for controlled cation mixing and prevention of higher manganese oxidation states, thereby reducing production costs and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional hydroxide co-precipitation method is used for synthesis, then cathode materials can be produced, but production cost becomes high and process becomes complicated
Solution Approach 1:
The patent combines multiple synthesis steps into a single solid-state reaction process. Instead of separate hydroxide co-precipitation, filtration, drying, and calcination steps, the invention directly reacts metal oxides or carbonates with lithium sources in one calcination step to form the final cathode material, thereby simplifying the manufacturing process
Solution Approach 2:
The invention extracts and eliminates the complex hydroxide co-precipitation intermediate steps from the synthesis pathway. By using direct solid-state reaction of metal precursors with lithium compounds, the method removes unnecessary processing stages while maintaining product quality
2Ease of manufacture
If solid state synthesis process is used, then production cost is reduced, but control over cation mixing is limited affecting electrochemical performance
Solution Approach 1:
The patent performs preliminary mixing of metal oxide or carbonate precursors with lithium sources before the calcination reaction. This pre-mixing ensures homogeneous distribution of cations before the reaction occurs, allowing better control over the final cation mixing in the crystal structure while maintaining the cost-effective solid-state synthesis approach
Solution Approach 2:
The invention optimizes reaction parameters such as calcination temperature, holding time, and precursor ratios to control the degree of cation mixing. By adjusting these parameters, the method achieves desired electrochemical performance while maintaining low production costs through solid-state synthesis
3Productivity
If higher oxidation states of manganese are present during synthesis, then reaction proceeds, but electrochemical performance deteriorates
Solution Approach 1:
The patent conducts the calcination reaction in a controlled atmosphere (inert or reducing atmosphere) to prevent oxidation of manganese to higher oxidation states. This protective environment allows the reaction to proceed to completion while maintaining manganese in the desired oxidation state, ensuring both productivity and electrochemical performance
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 enables the production of high-energy-density cathode materials with controlled cation mixing, reducing production costs and enhancing electrochemical performance, while also allowing for the recycling of manganese-containing cathodes from waste batteries.
Implementation Method 1
reacting a mixture of nickel, manganese, cobalt, and/or lithium precursors and calcining to form an oxide
Data Source
AI summary
The present disclosure provides methods for producing cathode materials for lithium ion batteries. Cathode materials that contain manganese are emphasized. Representative materials include LixNi1−y−zMnyCozO2 (NMC) (where x is in the range from 0.80 to 1.3, y is in the range from 0.01 to 0.5, and z is in the range from 0.01 to 0.5), LixMn2O4 (LM), and LixNi1−yMnyO2 (LMN) (where x is in the range from 0.8 to 1.3 and y is in the range from 0.0 to 0.8). The process includes reactions of carboxylate precursors of nickel, manganese, and/or cobalt and lithiation with a lithium precursor. The carboxylate precursors are made from reactions of pure metals or metal compounds with carboxylic acids. The manganese precursor contains bivalent manganese and the process controls the oxidation state of manganese to avoid formation of higher oxidation states of manganese.