Positive Electrode Composition With Reduced Conductive Additive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the optimal amount of conductive materials in rechargeable lithium batteries are inefficient, particularly when using layered lithium nickel-manganese-based composite oxides, leading to issues with electron conductivity, resistance, and cycle-life characteristics.
Innovation Solution
A method is developed to derive the minimum or reduced amount of conductive material in positive electrodes using the specific surface area of layered lithium nickel-manganese-based composite oxides, adhering to the equation y=1.092x^2 + 0.102x + 0.747, where x is the specific surface area and y is the content of the conductive material, optimizing the composition to enhance electron conductivity and cycle-life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the amount of conductive material is increased to improve electron conductivity, then electrical conductivity is improved, but the energy density and capacity of the battery decreases due to higher material content requirements
Solution Approach 1:
The patent changes the physical state of the conductive material from bulk powder to nanoscale particles (1-100 nm), fundamentally altering the parameter of particle size. This enables the conductive material to form effective networks at much lower weight percentages (0.1-5 wt%), simultaneously improving electrical conductivity while preserving energy density by minimizing the amount of non-active material required.
Solution Approach 2:
The patent utilizes the porous structure created by nanoscale conductive material particles dispersed throughout the electrode. This porous network provides extensive surface area and conductive pathways throughout the electrode matrix, enabling efficient electron transport without requiring high material loading, thus resolving the contradiction between conductivity and energy density.
2Measurement precision
If traditional methods are used to determine conductive material amount by preparing slurry and measuring resistance, then resistance measurement is possible, but the process is inefficient and time-consuming
Solution Approach 1:
The patent establishes predetermined relationships between conductive material content and electrode performance characteristics through prior experimentation. These pre-determined optimal ratios are then applied directly to formulation, eliminating the need for iterative slurry preparation and resistance measurement during normal production, thus significantly improving productivity while maintaining measurement precision.
Solution Approach 2:
Instead of performing actual resistance measurements on electrode plates, the patent uses pre-established data models and relationships that copy the essential information about optimal conductive material content. This allows rapid determination of appropriate material amounts without repeating the time-consuming measurement process for each batch.
Data Source
AI summary
A positive electrode includes a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector and including a positive electrode active material and a conductive material. The positive electrode active material includes a layered lithium nickel-manganese-based composite oxide. The positive electrode may derive a reduced amount of a required conductive material using only the information of the positive electrode active material, thereby realizing high capacity and low mixture resistance, thereby enabling the realization of a long cycle-life.