Nickel Hydroxide Precursor Void Structure for Lower Battery Resistance
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Solution Overview
Problem
Lithium-ion secondary batteries face challenges in reducing reaction resistance to enhance output voltage, particularly with lithium-nickel composite oxides used as positive electrode active materials in non-aqueous electrolyte secondary batteries.
Innovation Solution
Incorporating nickel composite hydroxide particles with specific void distributions, where the average void area ratio is between 0.5% and 5.0% and standard deviation is less than or equal to 1.0, to create a positive electrode active material precursor that reduces reaction resistance when used in non-aqueous electrolyte secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lithium-nickel composite oxide is used as positive electrode active material, then cost is reduced and capacity is increased, but reaction resistance increases and output voltage decreases
Solution Approach 1:
The patent applies porous materials by controlling the void structure within nickel composite hydroxide particles. The void ratio is specifically controlled between 3-15% and void diameter between 0.5-5 μm to create optimal pathways for lithium ion transport. This porous structure reduces reaction resistance while maintaining high capacity, resolving the contradiction between using lithium-nickel composite oxide for cost reduction and capacity increase versus the resulting high reaction resistance and low output voltage.
Solution Approach 2:
The patent applies parameter changes by precisely controlling physical parameters of the nickel composite hydroxide particles including void ratio (3-15%), void diameter (0.5-5 μm), and particle size (3-15 μm). These parameter optimizations enable the material to achieve both low reaction resistance and high output voltage while maintaining the cost advantages of lithium-nickel composite oxide over lithium-cobalt composite oxide.
2Reliability
If lithium-cobalt composite oxide is used as positive electrode active material, then output voltage and cycle characteristics are improved, but cost significantly increases
Solution Approach 1:
The patent applies this principle by replacing expensive cobalt-based materials with cheaper nickel-based materials (lithium-nickel composite oxide). While nickel-based materials traditionally have poorer cycle characteristics, the patent compensates through optimized void structure control (3-15% void ratio, 0.5-5 μm void diameter) that improves reaction resistance and stability, thereby achieving cost reduction while maintaining acceptable cycle characteristics.
3Object-affected harmful factors
If void ratio in nickel composite hydroxide particles is increased, then reaction resistance is reduced, but particle density decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the void ratio to a specific range (3-15%) and void diameter (0.5-5 μm). This controlled parameter adjustment creates sufficient void spaces to reduce reaction resistance while avoiding excessive void content that would significantly reduce particle density. The balanced parameter selection resolves the contradiction between reducing reaction resistance and maintaining particle density for high energy density batteries.
Data Source
AI summary
A positive electrode active material precursor for a non-aqueous electrolyte secondary battery, including-nickel composite hydroxide particles, is provided, wherein a cross section of each nickel composite hydroxide particle includes voids, and an average value of a ratio of an area of the voids in an area of each of the plurality of regions partitioned by predetermined boundary lines, is greater than or equal to 0.5% and less than or equal to 5.0%, and a standard deviation of the ratio of the area of the voids in the area of each of the plurality of regions partitioned by the predetermined boundary lines, is less than or equal to 1.0.