Radial Nickel-Based Active Material for Lithium Secondary Battery
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Solution Overview
Problem
Lithium secondary batteries with traditional nickel-based active materials face issues of reduced lifespan and capacity due to cracking and increased resistance during charging and discharging processes, which limits their energy density and efficiency.
Innovation Solution
A nickel-based active material is developed with secondary particles composed of radially arranged plate primary particles, featuring a higher porosity in the exterior portion than the interior, which enhances lithium diffusivity and reduces stress during volume changes, thereby improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional nickel-based active materials are used, then high energy density can be achieved, but crack generation occurs during charging and discharging which deteriorates battery life
Solution Approach 1:
The active material is divided into plate primary particles that are radially arranged within secondary particles. This segmentation allows each primary particle to independently accommodate volume changes during lithium insertion/extraction, preventing crack propagation through the entire particle structure and thereby maintaining battery life while preserving energy density.
Solution Approach 2:
The patent creates a non-uniform porosity distribution where the exterior portion of secondary particles has higher porosity (5-30%) than the interior portion. This local quality variation allows the exterior to buffer mechanical stress from volume changes while the interior maintains structural integrity, preventing cracks and extending battery life without sacrificing energy density.
2Quantity of substance
If traditional nickel-based active materials are used, then high capacity can be achieved, but resistance increases during charging and discharging processes
Solution Approach 1:
The patent introduces a controlled porous structure in the exterior portion of secondary particles with porosity of 5-30%. These pores facilitate electrolyte penetration and lithium ion transport, reducing resistance during charging and discharging while maintaining high capacity through the preserved active material content.
3Ease of manufacture
If uniform porosity is applied throughout the particle, then manufacturing is simplified, but lithium diffusion efficiency is reduced
Solution Approach 1:
The patent implements a gradient porosity structure where the exterior portion has higher porosity (5-30%) to enhance lithium diffusion, while the interior portion maintains lower porosity for structural stability. This local differentiation optimizes lithium ion transport pathways without significantly complicating the manufacturing process.
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 nickel-based active material enhances the initial efficiency, capacity, and lifetime of lithium secondary batteries by facilitating lithium diffusion and minimizing crack occurrence, leading to improved charge/discharge characteristics and extended battery life.
Implementation Method 1
facilitating lithium diffusion
Implementation Method 2
minimizing crack occurrence
Data Source
Figure 1A~1B
Figure 1C
Figure 2
AI summary
Provided are a nickel-based active material for a lithium secondary battery, a method of preparing the nickel-based active material, and a lithium secondary battery including a positive electrode including the nickel-based active material. The nickel-based active material may include a secondary particle including an agglomerate of at least two plate primary particles, wherein at least a part of the secondary particle has a structure in which the plate primary particles are arranged radially, and a porosity of an exterior portion of the secondary particle is greater than that of an interior portion of the secondary particle.