Cathode Active Material Processing with Anhydrous Lithium Firing
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Solution Overview
Problem
The existing methods for manufacturing positive electrode active materials for lithium secondary batteries face challenges in improving productivity and yield due to low reactivity between the precursor and lithium raw material, particularly when using hydrated lithium hydroxide, which leads to lower quality and higher energy consumption.
Innovation Solution
A method involving dry-mixing a transition metal hydroxide with an anhydrous lithium raw material, followed by primary and secondary firing steps, to enhance reactivity and produce a lithium transition metal oxide with improved quality and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If LiOH·H2O (hydrate) is used as the lithium raw material, then the manufacturing process is simpler, but the reactivity between the lithium raw material and the precursor is lowered, resulting in lower yield and lower productivity
Solution Approach 1:
The patent changes the physical and chemical parameters of the lithium raw material from hydrated form (LiOH·H2O) to anhydrous form (LiOH). This parameter change eliminates the water molecule that interferes with the oxidation reaction, thereby improving reactivity between the lithium raw material and the precursor, increasing yield and productivity while maintaining ease of manufacture through optimized processing conditions
2Ease of operation
If LiOH·H2O (hydrate) is used as the lithium raw material, then the handling is easier, but the reactivity between the lithium raw material and the precursor is lowered, resulting in lower yield
Solution Approach 1:
The patent changes the chemical composition parameter of the lithium raw material from hydrated to anhydrous form. This change improves the chemical reactivity and oxidation efficiency, thereby increasing the manufacturing yield. The ease of operation is maintained through optimized mixing and firing process parameters that accommodate the anhydrous material
3Device complexity
If conventional firing method is used, then the process is simpler, but the reactivity between the lithium raw material and the precursor is lowered, resulting in lower productivity
Solution Approach 1:
The patent segments the conventional single-step firing process into two distinct stages: first firing at a lower temperature (400-600°C) to initiate the reaction, followed by second firing at a higher temperature (600-800°C) to complete the oxidation. This segmentation improves reactivity and productivity by controlling the reaction progression, while the overall process complexity remains manageable through standardized procedural steps
4Quantity of substance
If LiOH·H2O is used as the lithium raw material, then the cost is lower, but the energy consumption is higher due to lower reactivity requiring longer firing time
Solution Approach 1:
The patent changes the lithium raw material from hydrated to anhydrous form, which significantly improves reactivity. This allows the oxidation reaction to proceed more efficiently and completely within a shorter firing time, thereby reducing energy consumption. The cost is maintained through efficient use of the anhydrous lithium hydroxide material
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 increases the production yield and quality of the positive electrode active material by improving reactivity and reducing energy consumption, while also enhancing the thermal stability and capacity characteristics of the final product.
Implementation Method 1
a positive electrode active material is synthesized by mixing and firing a positive electrode active material precursor and a lithium raw material and allowing an oxidation reaction between lithium and the precursor
Implementation Method 2
a first step of dry-mixing a transition metal hydroxide and an anhydrous lithium raw material to form a mixture; a second step of subjecting the mixture to primarily firing to form a primarily fired material
Data Source
Figure 1
AI summary
Provided are a manufacturing method of a positive electrode active material for a lithium secondary battery including: a first step of dry-mixing a transition metal hydroxide and an anhydrous lithium raw material; a second step of subjecting the mixture of the transition metal hydroxide and the anhydrous lithium raw material to primarily firing; and a third step of finely pulverizing and mixing the primarily fired material and performing secondary firing, and thus obtaining a lithium transition metal oxide, wherein, in the first step, the anhydrous lithium raw material is mixed at 40 parts by weight or less based on 100 parts by weight of the transition metal hydroxide, and a positive electrode for a lithium secondary battery including a positive electrode active material manufactured by the above-described manufacturing method, and a lithium secondary battery.