Flexible Coating for High-Voltage Ternary Cathode Particle Integrity
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Solution Overview
Problem
Ternary positive electrode materials in lithium-ion batteries face issues with particle breakage during high-voltage and high-temperature charging and discharging, leading to side reactions that affect cycle performance and safety.
Innovation Solution
A high-voltage ternary positive electrode material is developed by coating ternary positive electrode active material particles with a flexible coating body composed of a mixture of polyaniline and polyurethane elastomer, which enhances flexibility and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If ternary positive electrode material is charged and discharged at high voltage and high temperature, then capacity and energy density are improved, but particle breakage occurs due to intense reaction and strong anisotropic stress
Solution Approach 1:
The patent applies a flexible coating layer comprising polyurethane elastomer and polyaniline on the surface of the ternary positive electrode material particles. This flexible coating acts as a protective shell that can accommodate volume changes and stress during charging and discharging, preventing particle breakage while maintaining structural integrity. The coating thickness is controlled at 0.1-5 μm to provide protection without excessive impedance.
Solution Approach 2:
The patent uses a composite coating material consisting of polyurethane elastomer as the base matrix and polyaniline as the functional additive. The polyurethane elastomer provides flexibility and mechanical strength, while the conductive polyaniline enhances electrical conductivity. This composite structure synergistically combines the advantages of both materials to protect the electrode particles during high-voltage operation.
2Strength
If flexible coating body is applied to maintain particle integrity, then particle breakage is reduced, but coating complexity and manufacturing steps increase
Solution Approach 1:
The patent prepares the flexible coating material in advance by mixing polyurethane elastomer and polyaniline to form a coating slurry before the coating process. This preliminary preparation ensures uniform composition and facilitates the subsequent coating operation, reducing process complexity during production.
Solution Approach 2:
The patent uses a dispersant as an intermediary substance to facilitate the uniform mixing of polyurethane elastomer and polyaniline in the coating slurry. The dispersant ensures homogeneous distribution of components, enabling smooth coating application and simplifying the overall 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 flexible coating body maintains interface stability and integrity of the active material particles, reduces side reactions, and improves both cycle performance and safety performance of the battery.
Implementation Method 1
the flexible coating body has both flexibility and conductivity, the flexible coating body can adapt to interface changes of the ternary positive electrode active material particles
Implementation Method 2
the flexible coating body comprising a mixture of polyaniline and a polyurethane elastomer has both flexibility and conductivity
Implementation Method 3
the flexible coating body can provide a uniform lithium ion transmission interface for lithium ion deintercalation
Data Source
AI summary
A high-voltage ternary positive electrode material includes ternary positive electrode active material particles and a flexible coating body, the flexible coating body being coated on surfaces of the ternary positive electrode active material particles; wherein, the flexible coating body includes a mixture of polyaniline and a polyurethane elastomer.