WO3-Modified Positive Electrode Material for Lithium Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rechargeable lithium batteries face issues with increased internal resistance due to corrosion of the current collector, which affects high-rate and cycle-life characteristics, especially when using aqueous binders.
Innovation Solution
Incorporating WO3 into the positive active material composition, which acts as an oxidant to absorb OH- ions, reducing pH and preventing corrosion of the current collector, while using an organic binder to maintain the composite structure and improve electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an aqueous binder is used in the positive electrode composition, then ease of manufacture is improved, but internal resistance increases due to current collector corrosion
Solution Approach 1:
WO3 is introduced as an intermediary substance between the aqueous binder and the current collector. The WO3 absorbs OH- ions generated by the aqueous binder, preventing direct contact between the corrosive binder and the current collector, thereby eliminating internal resistance increase while maintaining manufacturing ease
Solution Approach 2:
The chemical environment at the interface between the binder and current collector is changed by introducing WO3. The WO3 consumes OH- ions, altering the local pH and chemical composition to prevent corrosion, thus resolving the contradiction between using aqueous binders and maintaining low internal resistance
2Reliability
If WO3 is added to absorb OH- ions and prevent corrosion, then reliability is improved, but device complexity increases
Solution Approach 1:
WO3 is combined with the positive active material particles to form a composite structure. This merging integrates the corrosion prevention function directly into the electrode material system, avoiding the need for separate protective layers or additional components, thus minimizing device complexity while improving reliability
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 solution effectively suppresses internal resistance increase, enhancing the high-rate and cycle-life characteristics of rechargeable lithium batteries by preventing current collector corrosion and maintaining the structural integrity of the positive electrode.
Implementation Method 1
WO3, which acts as an oxidant to absorb OH- ions
Implementation Method 2
absorb OH- ions
Data Source
AI summary
A positive active material composition for a rechargeable lithium battery that includes a positive active composite material including a compound being reversibly capable of intercalating and deintercalating lithium, WO3, and a binder; and an aqueous binder, a positive electrode for a rechargeable lithium battery including the positive active material composition, and a rechargeable lithium battery comprising the positive electrode including the positive active material composition.