Azole-Coated Positive Electrode Additive for High-Nickel Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rechargeable lithium batteries face challenges in achieving high energy density and capacity due to issues such as surface degradation, increased resistance, and reduced cycle-life caused by high nickel content in the positive electrode active material, leading to degradation and performance loss.
Innovation Solution
Incorporation of a functional additive, specifically an azole-based compound, into the positive electrode active material layer to form a coating that reduces surface degradation and stabilizes the electrode, along with a sacrificial positive electrode material to supplement lithium, thereby improving stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high nickel content is used in the positive electrode active material to increase energy density and capacity, then the energy density and capacity are improved, but surface degradation, resistance increase, and cycle-life reduction occur
Solution Approach 1:
An azole-based compound is introduced as an intermediary substance between the high-nickel positive electrode active material and the electrolyte. This compound forms a protective coating layer on the surface of the active material particles, acting as a mediator that prevents direct harmful interactions while allowing beneficial lithium ion insertion/extraction. The intermediary layer stabilizes the electrode surface, reducing degradation and maintaining cycle-life despite high nickel content.
Solution Approach 2:
The positive electrode is constructed as a composite material system combining high-nickel active material particles with an azole-based compound coating. This composite structure leverages the high capacity of nickel while the azole compound provides protective functions, creating a synergistic material system that achieves both high energy density and improved stability/cycle-life.
2Use of energy by moving object
If high nickel content is used in the positive electrode active material to increase energy density and capacity, then the energy density and capacity are improved, but surface degradation and resistance increase occur
Solution Approach 1:
The azole-based compound serves as a protective intermediary layer on the surface of high-nickel active material particles. This intermediary coating prevents direct exposure of the nickel surface to the electrolyte, thereby eliminating surface degradation and resistance increase while preserving the high energy density benefits of nickel.
Solution Approach 2:
A thin film coating of the azole-based compound is formed on the surface of the positive electrode active material particles. This flexible thin film provides protective coverage that prevents harmful surface reactions and degradation, while maintaining the underlying high-nickel material's energy storage capabilities.
3Reliability
If a functional additive is added to the positive electrode active material layer to improve stability and cycle-life, then the cycle-life and stability are improved, but the device complexity increases
Solution Approach 1:
The invention optimizes the concentration parameter of the azole-based compound additive within a specific range (0.03-0.3 parts by weight per 100 parts by weight of active material). By controlling this parameter, the patent achieves improved cycle-life and stability without excessive complexity, as the additive is used in small, precisely controlled amounts rather than large quantities.
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 azole-based compound enhances the processability and cycle-life of the battery by reducing surface reactions, maintaining capacity, and preventing lithium elution, thus improving the overall performance and stability of the rechargeable lithium battery.
Implementation Method 1
Incorporation of a functional additive, specifically an azole-based compound, into the positive electrode active material layer to form a coating that reduces surface degradation and stabilizes the electrode
Implementation Method 2
a sacrificial positive electrode material to supplement lithium
Implementation Method 3
the rechargeable lithium battery generates electrical energy caused by oxidation and reduction reactions when lithium ions are intercalated and deintercalated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is an additive for a positive electrode of a rechargeable lithium battery. A positive electrode active material layer includes a positive electrode active material, a sacrificial positive electrode material, a functional additive, a conductive material, and a binder. The functional additive includes an azole-based compound. An amount of the functional additive is in a range of from about 0.03 parts by weight to about 0.3 parts by weight relative to 100 parts by weight of the positive electrode active material layer.