Nickel-Based Cathode Oxide Composition With Soluble Sulfur Control
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Solution Overview
Problem
Current positive electrode active materials for electrochemical cells in electric and hybrid electric vehicles lack improved electrochemical properties such as first charge capacity and capacity fading rate, with specific surface area being a key limiting factor.
Innovation Solution
A lithium transition metal-based oxide positive electrode active material with a specific surface area between 0.6 m2/g and 1.1 m2/g, comprising Ni, Co, Mn, and soluble sulfur, along with other elements, optimized through a manufacturing process involving mixing with a sulfur-containing compound and heating in an oxidizing atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the specific surface area of positive electrode active material is increased to improve first charge capacity and capacity fading rate, then electrochemical performance is enhanced, but manufacturing complexity and process control difficulty increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the sulfur content (0.1-0.8 mol%) and specific surface area (0.6-1.1 m2/g) of the positive electrode active material. By optimizing these physical and chemical parameters within specific ranges, the invention achieves improved first charge capacity (≥212 mAh/g) and capacity fading rate (≤20%/100 cycles) while maintaining manufacturability through controlled parameter specifications.
Solution Approach 2:
The patent employs composite materials by incorporating sulfur-containing compounds into the lithium transition metal-based oxide structure. This creates a composite positive electrode active material where sulfur is integrated at the molecular level, achieving both enhanced electrochemical performance and controlled surface area without requiring complex external coating processes.
2Reliability
If soluble sulfur content is optimized to enhance first charge capacity, then electrochemical performance improves, but measurement precision and quality control become more challenging
Solution Approach 1:
The patent transforms the measurement challenge by establishing a specific parameter range for soluble sulfur content (0.1-0.8 mol%) that correlates directly with electrochemical performance. This parameter optimization approach converts the measurement difficulty into a controllable quality specification, where ICP measurement within this range provides sufficient precision for quality control while ensuring improved first charge capacity (≥212 mAh/g).
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 material achieves a first charge capacity of at least 212 mAh/g and a capacity fading rate of no more than 20%/100 cycles, enhancing the electrochemical performance of electrochemical cells.
Implementation Method 1
heating in an oxidizing atmosphere
Implementation Method 2
a material capable to capture and release Li ions when subjected to a voltage change
Data Source
AI summary
The invention relates to a positive electrode active material for suitable for electric vehicle (EV) and hybrid electric vehicle (HEV) applications, wherein said material comprises lithium transition metal-based oxide particles comprising soluble S content and having a high specific surface area.