Nickel-Manganese Hydroxide Particle Structure for High-Fillability Cathodes
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Solution Overview
Problem
Current methods for producing nickel-manganese composite hydroxide and lithium-ion secondary battery active materials are inefficient in enhancing battery capacity, output characteristics, and cycle stability, and lack industrial-scale production methods with reduced costs.
Innovation Solution
A nickel-manganese composite hydroxide with a specific particle structure and crystallinity is produced using a controlled crystallization process, involving controlled concentrations of nickel and manganese, oxygen, and stirring power, which is then used to create a positive electrode active material with improved radial particle orientation and porosity, enhancing battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the active material having a narrow particle size distribution with a uniform particle diameter is used to enhance capacity per unit weight, then battery capacity and life are improved, but particle fillability deteriorates leading to low volume energy density
Solution Approach 1:
The invention segments the particle population into two distinct size ranges (first particle diameter range for high capacity, second particle diameter range for high fillability) and combines them in a composite positive electrode. This allows each particle size segment to fulfill its specific function: smaller particles provide high surface area for electrochemical reactions while larger particles provide good packing efficiency, thereby resolving the contradiction between capacity and volume energy density
Solution Approach 2:
The invention applies local quality by assigning different particle size characteristics to different regions/functions within the positive electrode. Specifically, particles with first particle diameters (optimized for capacity) and particles with second particle diameters (optimized for fillability) are distributed throughout the electrode structure, allowing each local region to contribute its specialized property to the overall battery performance
2Volume of moving object
If particles having different particle diameters are mixed to enhance particle fillability, then volume energy density and rate characteristic are improved, but production cost increases due to additional processes
Solution Approach 1:
The invention changes the particle diameter parameter by controlling precipitation conditions (such as pH, temperature, mixing rate, and reagent addition speed) during the hydroxide production process to directly generate particles with different size ranges in a single step. This eliminates the need for separate size classification and mixing processes, thereby reducing manufacturing complexity and cost while achieving the desired multi-size particle composition for high fillability
3Quantity of substance
If a precursor hydroxide is lightly crushed followed by granulation and spheroidization to enhance capacity per unit weight, then open pore ratio is improved, but the process becomes non-industrial and unsuitable for mass production
Solution Approach 1:
The invention performs preliminary action by controlling the particle morphology and structure during the precipitation process itself, rather than requiring subsequent crushing and granulation steps. By adjusting precipitation parameters (pH, temperature, mixing conditions, reagent types), the hydroxide particles are formed with inherent high open pore ratios and favorable structures that maintain mass production capability while achieving high capacity per unit weight
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 approach results in a nickel-manganese composite hydroxide that improves battery capacity, output characteristics, and cycle stability, enabling high-capacity, long-life nonaqueous electrolyte secondary batteries with reduced production costs and industrial scalability.
Implementation Method 1
a crystallization process of forming a nickel-manganese composite hydroxide by neutralizing a salt containing at least nickel and a salt containing at least manganese in an aqueous reaction solution
Implementation Method 2
forming a nickel-manganese composite hydroxide by neutralizing a salt containing at least nickel and a salt containing at least manganese in an aqueous reaction solution
Data Source
AI summary
Provided are a nickel-manganese composite hydroxide capable of producing a secondary battery having a high particle fillability and excellent battery characteristics when used as a precursor of a positive electrode active material and a method for producing the same. A nickel-manganese composite hydroxide is represented by General Formula: NixMnyMz(OH)2+α and contains a secondary particle formed of a plurality of flocculated primary particles. The primary particles have an aspect ratio of at least 3, and at least some of the primary particles are disposed radially from a central part of the secondary particle toward an outer circumference thereof. The secondary particle has a ratio I(101)/I(001) of a diffraction peak intensity I(101) of a 101 plane to a peak intensity I(001) of a 001 plane, measured by an X-ray diffraction measurement, of up to 0.15.