Positive Electrode Binder Composition for High-Temperature Li-Ion Cycling
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Solution Overview
Problem
Lithium-ion batteries face performance degradation due to transition metal dissolution from the positive electrode in high-temperature environments, leading to side reactions and impedance increase, which existing surface coatings and material gradient designs fail to adequately address, especially for low-cobalt or cobalt-free materials.
Innovation Solution
A positive electrode plate using a polymer binder with a specific structural formula, including chain segments and cyano-CN, reduces metal dissolution by minimizing contact area and complexing transition metal ions, thereby inhibiting side reactions and improving high-temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If material gradient design is used to inhibit metal dissolution, then metal dissolution is reduced, but the process becomes complex and cost increases
Solution Approach 1:
The patent makes the binder serve multiple functions: it not only binds the positive electrode active material particles together but also complexes with transition metal ions to inhibit their dissolution. This multi-functionality eliminates the need for separate coating layers or complex gradient structures, simplifying the preparation process while maintaining effectiveness
Solution Approach 2:
The binder automatically complexes with transition metal ions as they dissolve from the positive electrode active material, providing self-inhibition without requiring external intervention or complex processing steps. The system uses its own binder component to solve the dissolution problem inherently
2Ease of manufacture
If conventional binder is used, then preparation is simple, but side reactions occur at positive electrode interface during high-temperature storage and cycling
Solution Approach 1:
The patent changes the chemical composition parameters of the binder by selecting polymers with specific functional groups that have high affinity for transition metal ions. This parameter change enables the binder to effectively complex with dissolved metals, transforming the inhibition mechanism from physical barrier (coating) to chemical complexation
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 polymer binder effectively reduces metal dissolution, enhances high-temperature storage and cycle performance, and maintains battery safety with low preparation costs, suitable for low-cobalt or cobalt-free materials.
Implementation Method 1
the polymer includes a chain segment a, a chain segment b, and a chain segment c... the binder includes a polymer having a structural formula as shown in Formula I
Data Source
AI summary
Disclosed are a positive electrode plate, a preparation method therefor and the use thereof. The positive electrode plate comprises a current collector and an active substance layer formed on the current collector, wherein the active substance layer comprises a positive electrode active material, a conductive agent and a binder, with the binder comprising a polymer with the structural formula as shown in formula I, which polymer comprises chain segments a, b and c. The positive electrode plate not only has a low preparation cost, but can also significantly improve the high-temperature storage and high-temperature cycle performance of a lithium-ion battery.